Head-mounted device and optical system thereof

Abstract

The utility model provides a head-mounted device and an optical system thereof, the optical system of the head-mounted device comprises a lens cone, a lens group and a spacing element, and the lens group comprises a reflective polarizing element, a quarter-wave plate, a first lens, a second lens and a third lens. The reflective polarizing element, the quarter-wave plate and the first lens form an optical element group, the spacing elements comprise a first spacing element and a second spacing element, the first spacing element is located between the first lens and the second lens, and the optical system meets the following conditions: 0.9 lt; l / flt; 1.4 lt and 1.4 lt; d1m / F1lt; f is the effective focal length of the optical system, L is the maximum horizontal distance from the object side surface of the lens barrel to the image side surface of the lens barrel in the optical axis direction, F1 is the focal length of the optical element group, and d1m is the inner diameter of the plane, perpendicular to the optical axis, of the image side surface of the spacing element.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of optical system especially relates to a head-mounted device and optical system thereof. BACKGROUND

[0002] In recent years, with the rapid development of virtual reality (VR) and augmented reality (AR) technology, it has been widely used in the gaming, education and other industries, the demand for head-mounted devices is increasing. However, the existing head-mounted device optical system still has some problems in imaging quality, field of view, size and other aspects. For example, the outer field of view picture is blurred, the imaging quality needs to be improved, the barrel size is large, which affects the wearing comfort, etc.

[0003] The continuous development of hardware technology is one of the key factors to promote the maturity of VR / AR technology. With the continuous improvement of processor performance, VR / AR devices can run complex graphics and computing tasks more smoothly, providing users with more realistic visual effects. The progress of display technology also makes the picture of VR / AR device clearer, more delicate, and more colorful. At the same time, the development of sensor technology enables VR / AR devices to more accurately capture user motion and position information, achieving a more natural interactive experience.

[0004] Among them, using light path folding scheme to design VR / AR lens is an important technical innovation. Traditional VR / AR lens is usually large in size and heavy in weight, which is not comfortable to wear. By using light path folding scheme, the body length of the lens can be compressed to half of the original, so that the center of gravity of the head-mounted device moves backward, greatly reducing the burden on the user's head and optimizing the user's experience. This design not only makes the device more portable, but also improves the stability and comfort of wearing.

[0005] At present, the device based on light path folding has been released and has attracted widespread attention in the market. However, from the actual experience of users, these devices still have some shortcomings. Among them, the outer field of view picture is relatively blurred, which is a more prominent problem. This is mainly due to the limitations of the light path folding scheme in design, which leads to unstable light transmission in the outer field of view, thereby affecting the clarity of the picture. In addition, the imaging quality of the 2-piece lens also needs to be improved. Although the 2-piece lens can meet the basic needs of users to some extent, there are still some shortcomings in the contrast and color restoration of the image.

[0006] An important reason for these problems is the previous limitation of the film pasting technology. In the manufacturing process of VR / AR lenses, film pasting technology is a key process. However, due to the limitations of technology, the precision and quality of film pasting are difficult to guarantee, thereby affecting the performance of the lens. In addition, due to the limitation of the film pasting technology, the freedom of the lens in the scheme is less, and the performance of the optical system cannot be fully utilized. This also leads to the performance of the system to be improved, and cannot provide users with a better visual experience.

[0007] In order to solve these problems, researchers and engineers are constantly innovating and improving technology. On the one hand, they strive to improve the precision and quality of the film pasting technology, and by using more advanced film pasting equipment and processes, ensure that the performance of the lens is fully utilized. On the other hand, they are also exploring new lens design schemes, increasing the freedom of the lens, and improving the performance of the optical system. At the same time, they are constantly optimizing the performance of hardware devices, improving the operation speed of processors, the clarity of display technology, and the accuracy of sensors, to provide users with a smoother and more realistic visual experience. Practical new type content

[0008] One of the main advantages of the present utility model is to provide a head-mounted device and its optical system, wherein the optical system of the head-mounted device is based on a three-lens architecture, combined with curved film pasting technology, further shortening the thickness of the head-mounted device.

[0009] Another advantage of the present utility model is to provide a head-mounted device and its optical system, wherein the optical system of the head-mounted device improves the system performance and improves the visual experience of consumers.

[0010] Another advantage of the present utility model is to provide a head-mounted device and its optical system, wherein the optical system of the head-mounted device controls part of the structure size, controls the module cost, and improves the market competitiveness.

[0011] Another advantage of the present utility model is to provide a head-mounted device and its optical system, wherein the optical system controls the focal length of the optical imaging system, effectively constrains the field of view angle of the system, so that the system meets the characteristics of the large field of view of the VR lens.

[0012] Another advantage of the present utility model is to provide a head-mounted device and its optical system, wherein by constraining the size of the lens barrel, the size of the lens barrel is as small as possible under the premise of ensuring the processability of the lens barrel, thereby reducing the size of the whole machine.

[0013] The utility model discloses another advantage lies in providing a head-mounted device and its optical system, wherein by controlling the effective focal length of the first lens, the shape of the first lens is controlled, thereby determining the position conducive to RP film attachment; and by controlling the distance from the object side end face of the lens barrel to the first spacing element, the wall thickness of the front end face of the lens barrel and the mechanism diameter thickness of the first spacing element are controlled, which is conducive to the molding of the lens barrel and the lens; it is also conducive to controlling the size of the components.

[0014] The utility model discloses another advantage lies in providing a head-mounted device and its optical system, wherein by controlling the effective focal length of the first lens, the shape of the first lens is controlled, thereby determining the position conducive to RP film attachment; and by controlling the distance from the object side end face of the lens barrel to the first spacing element, the wall thickness of the front end face of the lens barrel and the mechanism diameter thickness of the first spacing element are controlled, which is conducive to the molding of the lens barrel and the lens; it is also conducive to controlling the size of the components.

[0015] The utility model discloses another advantage lies in providing a head-mounted device and its optical system, wherein by controlling the effective focal length of the first lens, the shape of the first lens is controlled, thereby determining the position conducive to RP film attachment; and by controlling the distance from the object side end face of the lens barrel to the first spacing element, the wall thickness of the front end face of the lens barrel and the mechanism diameter thickness of the first spacing element are controlled, which is conducive to the molding of the lens barrel and the lens; it is also conducive to controlling the size of the components.

[0016] The utility model discloses another advantage lies in providing a head-mounted device and its optical system, wherein by controlling the effective focal length of the first lens, the shape of the first lens is controlled, thereby determining the position conducive to RP film attachment; and by controlling the distance from the object side end face of the lens barrel to the first spacing element, the wall thickness of the front end face of the lens barrel and the mechanism diameter thickness of the first spacing element are controlled, which is conducive to the molding of the lens barrel and the lens; it is also conducive to controlling the size of the components.

[0017] The utility model discloses another advantage lies in providing a head-mounted device and its optical system, wherein by controlling the effective focal length of the first lens, the shape of the first lens is controlled, thereby determining the position conducive to RP film attachment; and by controlling the distance from the object side end face of the lens barrel to the first spacing element, the wall thickness of the front end face of the lens barrel and the mechanism diameter thickness of the first spacing element are controlled, which is conducive to the molding of the lens barrel and the lens; it is also conducive to controlling the size of the components.

[0018] The utility model discloses another advantage lies in providing a head-mounted device and its optical system, wherein by controlling the effective focal length of the first lens, the shape of the first lens is controlled, thereby determining the position conducive to RP film attachment; and by controlling the distance from the object side end face of the lens barrel to the first spacing element, the wall thickness of the front end face of the lens barrel and the mechanism diameter thickness of the first spacing element are controlled, which is conducive to the molding of the lens barrel and the lens; it is also conducive to controlling the size of the components.

[0019] The utility model discloses another advantage lies in providing a head-mounted device and its optical system, wherein by controlling the effective focal length of the first lens, the shape of the first lens is controlled, thereby determining the position conducive to RP film attachment; and by controlling the distance from the object side end face of the lens barrel to the first spacing element, the wall thickness of the front end face of the lens barrel and the mechanism diameter thickness of the first spacing element are controlled, which is conducive to the molding of the lens barrel and the lens; it is also conducive to controlling the size of the components.

[0020] Another advantage of the head-mounted device and the optical system thereof is that the ratio between the inner diameter of the spacer element and the SAG value of the second lens image side is adjusted by a specific relationship, which optimizes the field of view to a certain extent; the relationship between the system size and performance can be balanced to a certain extent through reasonable adjustment.

[0021] Another advantage of the head-mounted device and the optical system thereof is that the ratio between the difference of the inner diameter of the lens barrel object side and the image side and the focal length is adjusted by a specific relationship, which can affect the propagation path of light and the imaging characteristics of the system, thereby optimizing the imaging quality to a certain extent. Through reasonable adjustment, the size of the system can be minimized while ensuring performance.

[0022] Another advantage of the head-mounted device and the optical system thereof is that the relative size and spacing between the spacer element and the lens are adjusted by a specific relationship, which can control the optical path length and optimize the imaging quality. Through the set proportional relationship, the manufacturing cost can be minimized while ensuring that the system performance meets the requirements.

[0023] Another advantage of the head-mounted device and the optical system thereof is that the size of certain elements in the system can be minimized while ensuring system performance. Through the set proportional range, clear guidance can be provided for the manufacturing and assembly process, thereby improving the manufacturing and assembly precision of the system and helping to reduce performance degradation caused by manufacturing and assembly errors.

[0024] According to one aspect of the present application, the optical system of the head-mounted device of the present application can achieve the aforementioned objectives and other objectives and advantages, and comprises:

[0025] A lens barrel;

[0026] A lens group, wherein the lens group comprises a reflective polarizing element, a quarter-wave plate, a first lens, a second lens, and a third lens, wherein the reflective polarizing element, the quarter-wave plate, and the first lens constitute an optical element group, and the optical element group has positive focal power, the second lens has positive focal power, the third lens has focal power, and the second lens image side and the third lens image side are convex, wherein the optical system satisfies the following conditions: 0.9 < L / f < 1.4 and 1.4 < d1m / F1 < 2.3, wherein f is the effective focal length of the optical system, L is the maximum horizontal distance of the lens barrel object side to the lens barrel image side along the optical axis, F1 is the focal length of the optical element group, and d1m is the inner diameter of the spacer element image side perpendicular to the plane of the optical axis.

[0027] According to an embodiment of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.30 < EP12 / (d1s-2*DT11) < 2.55, wherein EP12 is the interval distance between the image side surface of the first spacer element and the object side surface of the second spacer element in the direction along the optical axis, d1s is the inner diameter of the plane of the object side surface of the spacer element perpendicular to the optical axis, and DT11 is the maximum effective radius of the object side surface of the first lens.

[0028] According to an embodiment of the present application, the optical system of the head-mounted device further satisfies the following condition: 2.0 < (D1s-d1m) / |SAG11| ≤ 12.6, wherein d1m is the inner diameter of the plane of the image side surface of the first spacer element perpendicular to the optical axis, D1s is the outer diameter of the plane of the object side surface of the first spacer element perpendicular to the optical axis, and SAG11 is the on-axis distance between the intersection of the object side surface of the first lens and the optical axis and the vertex of the effective radius of the object side surface of the first lens.

[0029] According to an embodiment of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.80 < EP01 / CT1 < 1.25, wherein EP01 is the interval distance between the object side end surface of the lens barrel and the object side surface of the first spacer element in the direction along the optical axis, and CT1 is the center thickness of the first lens on the optical axis.

[0030] According to an embodiment of the present application, the optical system of the head-mounted device further satisfies the following condition: 1.4 ≤ L / EP02 < 1.7, wherein L is the maximum horizontal distance of the lens barrel from the object side end surface to the image side end surface in the direction along the optical axis, and EP02 is the interval distance between the object side end surface of the lens barrel and the object side surface of the second spacer element in the direction along the optical axis.

[0031] According to an embodiment of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.15 < CP1 / (CT1+T12) < 0.80, wherein CP1 is the maximum thickness of the first spacer element in the direction along the optical axis, CT1 is the center thickness of the first lens on the optical axis, and T12 is the air interval of the first lens and the second lens on the optical axis.

[0032] According to one embodiment of the utility model, optical system of headgear further satisfy following condition: 1.4 < CP2 / T23 < 6.2, wherein, CP2 is the maximum thickness of second interval element along the optical axis direction, T23 is the air interval of second lens and third lens on the optical axis.

[0033] According to one embodiment of the utility model, optical system of headgear further satisfy following condition: 2.05 < d0m / DT32 < 3.30, wherein, d0m is the inner diameter of lens barrel image side perpendicular to the plane of optical axis, DT32 is the maximum effective radius of third lens image side.

[0034] According to one embodiment of the utility model, optical system of headgear further satisfy following condition: 35.05 < d2m / |SAG22| < 59.35, wherein, d2m is the inner diameter of second interval element image side perpendicular to the plane of optical axis, SAG22 is the on-axis distance between the intersection of second lens image side and optical axis and the effective radius vertex point of second lens image side.

[0035] According to one embodiment of the utility model, optical system of headgear further satisfy following condition: 0.20 < (d0m-d0s) / f < 1.30, wherein, d0s is the inner diameter of lens barrel object side perpendicular to the plane of optical axis, d0m is the inner diameter of lens barrel image side perpendicular to the plane of optical axis.

[0036] According to one embodiment of the utility model, optical system of headgear further satisfy following condition: 0.95 < d1m / (DT12*2) < 1.20, wherein, d1m is the inner diameter of first interval element image side perpendicular to the plane of optical axis, DT12 is the maximum effective radius of first lens image side.

[0037] According to one embodiment of the utility model, optical system of headgear further satisfy following condition: 0.95 < (CP1+E12+CP2) / (T12+CT2+T23) < 2.80, wherein, CP1 is the maximum thickness of first interval element along the optical axis direction, CP2 is the maximum thickness of second interval element along the optical axis direction, T12 is the air interval of first lens and second lens on the optical axis, T23 is the air interval of second lens and third lens on the optical axis, CT2 is the center thickness of second lens on the optical axis.

[0038] According to one embodiment of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.05<CP2 / |SAG31|<0.30, wherein SAG31 is the on-axis distance between the intersection of the third lens object side and the optical axis and the effective radius vertex of the third lens object side.

[0039] According to one embodiment of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.05<CP2 / |SAG31|<0.30, wherein SAG31 is the on-axis distance between the intersection of the third lens object side and the optical axis and the effective radius vertex of the third lens object side.

[0040] According to another aspect of the present application, the present application further provides a head-mounted device, comprising:

[0041] a head-mounted device body; and

[0042] at least one optical system as described above, wherein the optical system is mounted on the head-mounted device body.

[0043] The further objects and advantages of the present application will be more fully understood from the following description and drawings.

[0044] These and other objects, features and advantages of the present application will become apparent from the following detailed description and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0045] The technical solutions of the present application will be further described in detail below in combination with the drawings and embodiments. In the drawings, the same reference signs are used to represent the same components unless otherwise specified. Among them:

[0046] Figure 1 is a structural schematic view of the optical system of the head-mounted device according to the first preferred embodiment of the present application.

[0047] Figure 2 is a structural schematic view of the optical system of the head-mounted device according to the second preferred embodiment of the present application.

[0048] Figure 3 is a structural schematic view of the optical system of the head-mounted device according to the third preferred embodiment of the present application.

[0049] Figure 4 is a structural schematic view of the optical system of the head-mounted device according to the fourth preferred embodiment of the present application.

[0050] Figure 5is a structural schematic diagram of an optical system of a head-mounted device according to a fifth preferred embodiment of the present application.

[0051] Figure 6 is a structural schematic diagram of an optical system of a head-mounted device according to a sixth preferred embodiment of the present application.

[0052] Figure 7 is a structural schematic diagram of an optical system of a head-mounted device according to a seventh preferred embodiment of the present application.

[0053] Figure 8 is a structural schematic diagram of an optical system of a head-mounted device according to an eighth preferred embodiment of the present application.

[0054] Figure 9 is a structural schematic diagram of an optical system of a head-mounted device according to a ninth preferred embodiment of the present application.

[0055] Figures 10A to 10C is a schematic diagram of axial chromatic aberration curve, astigmatism curve and distortion curve of the optical system of the head-mounted device according to the first to third preferred embodiments of the present application.

[0056] Figures 11A to 11C is a schematic diagram of axial chromatic aberration curve, astigmatism curve and distortion curve of the optical system of the head-mounted device according to the fourth to sixth preferred embodiments of the present application.

[0057] Figures 12A to 12C is a schematic diagram of axial chromatic aberration curve, astigmatism curve and distortion curve of the optical system of the head-mounted device according to the seventh to ninth preferred embodiments of the present application.

[0058] Figure 13 is a schematic diagram of size of the optical system of the head-mounted device according to the first preferred embodiment of the present application.

[0059] Figure 14 is a schematic diagram of size of the first lens of the optical system of the head-mounted device according to the first preferred embodiment of the present application. DETAILED DESCRIPTION

[0060] The following description is provided to enable any person skilled in the art to practice the present application. The preferred embodiments in the following description are only examples of implementing the present application and other obvious modifications are possible to those skilled in the art. The basic principles defined in the following description can be applied to other embodiments, variations, improvements, equivalents and other technical solutions without departing from the spirit and scope of the present application.

[0061] Those skilled in the art shall understand that in the disclosure of the utility model, the terms longitudinal, transverse, upper, lower, front, rear, left, right, vertical, horizontal, top, bottom, inner, outer and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the above terms cannot be understood as a limitation on the utility model.

[0062] It can be understood that the term one should be understood as at least one or one or more, that is, in one embodiment, the number of one element can be one, and in another embodiment, the number of the element can be multiple, and the term one cannot be understood as a limitation on the number.

[0063] Referring to the drawings of the present application Figures 1 to 14 As shown in the drawings, the optical system of a head-mounted device according to an aspect of the present application is illustrated in the following description. The optical system of the head-mounted device includes the lens barrel P0 and the lens group E assembled in the lens barrel P0 and at least one spacer element P. The lens group E includes a reflective polarizing element S1, a quarter-wave plate S2, a first lens E1, a second lens E2 and a third lens E3, wherein the at least one spacer element P is arranged between the first lens E1, the second lens E2 and the third lens E3. The optical system of the head-mounted device has an object side end and an image side end, wherein the reflective polarizing element S1, the quarter-wave plate S2, the first lens E1, the second lens E2 and the third lens E3 of the lens group E are arranged in order along the object side end (first side) to the image side end (second side) of the lens barrel P0.

[0064] Among them, the reflective polarizing element S1, the quarter-wave plate S2 and the first lens E1 constitute an optical element group E0, and the optical element group E0 has a positive focal power. Positive focal power means that the optical element group E0 can converge light, thereby playing an important role in the imaging process. It should be noted that in the preferred embodiment of the present application, the reflective polarizing element S1 can selectively reflect or transmit light of a specific polarization direction, thereby improving the contrast and color saturation of the image. The quarter-wave plate S2 can convert linearly polarized light into circularly polarized light or vice versa, further enhancing the performance of the optical system. The shape and parameters of the first lens E1 directly affect the imaging quality of the entire optical system.

[0065] Preferably, in this preferred embodiment of the present application, the reflective polarizing element S1 and the quarter-wave plate S2 are attached to the object side end of the first lens E1, i.e., the reflective polarizing element S1, the quarter-wave plate S2, and the first lens E1 are combined as the optical element group E0.

[0066] The reflective polarizing element S1 and the quarter-wave plate S2 of the optical element group E0 are located on the object side of the first lens E1, wherein the reflective polarizing element S1 can serve as the first object side surface of the optical element group E0, and the quarter-wave plate S2 serves as the second object side surface of the optical element group E0. Further, the first lens E1 has a first lens object side surface S3 facing the object side and a first lens image side surface S4 facing the image side, the second lens E2 has a second lens object side surface S5 facing the object side and a second lens image side surface S6 facing the image side, and the third lens E3 has a third lens object side surface S7 facing the object side and a third lens image side surface S8 facing the image side.

[0067] The second lens E2 has optical power, and its image side surface (i.e., the second lens image side surface S6) is convex. This can make the light rays more concentrated when passing through the second lens E2, thereby improving the clarity and brightness of the image. The convex image side surface can better collect and focus light rays, making the image more sharp.

[0068] The third lens E3 also has optical power, and its image side surface (i.e., the third lens image side surface S8) is also convex. Similar to the second lens E2, the convex image side surface of the third lens E3 can effectively collect light rays and improve the imaging quality. In addition, the optical power of the third lens E3 can cooperate with the first lens E1 and the second lens E2 to jointly adjust the focal length and field of view angle of the optical system to meet different application requirements.

[0069] The spacer element P further includes a first spacer element P1 and a second spacer element P2, wherein the first spacer element P1 is located between the first lens E1 and the second lens E2 and abuts against the second side surface of the first lens E1. The second spacer element P2 is arranged between the second lens E2 and the third lens E3.

[0070] It is worth mentioning that the function of the spacer element P is to keep the distance between the lenses stable, prevent collision and friction between the lenses, and thus ensure the stability and reliability of the optical system.

[0071] The lens barrel P0 has a lens barrel object side end surface P01 and a lens barrel image side end surface P02, wherein the lens barrel object side end surface P01 is located at the object side end of the lens barrel P0, and the lens barrel image side end surface P02 is located at the image side end of the lens barrel P0.

[0072] In order to ensure the performance of the optical system, the following condition needs to be met: 0.9 < L / f < 1.4. Wherein, f is the effective focal length of the optical system, L is the maximum horizontal distance of the lens barrel object side P01 to the lens barrel image side P02 of the lens barrel P0 along the optical axis direction. It can be understood that this technical condition of the optical system can effectively control the focal length of the optical system, thereby restricting the field of view angle of the system, so that the system meets the characteristics of the large field of view of the VR lens. The large field of view can make the user obtain a wider field of view when wearing the head-mounted device, and enhance the sense of immersion.

[0073] Further, the optical system further meets the following condition: 1.4 < d1m / F1 < 2.3, wherein F1 is the focal length of the optical element group E0, and d1m is the inner diameter of the spacer element P1 image side perpendicular to the plane of the optical axis. It is worth mentioning that when d1m / F1 is less than 1.4, a series of problems will be caused. First, the length of the lens barrel P0 is shorter, which leads to the propagation path of light in the lens barrel P0 not long enough. This will make the light easy to appear blurred or distorted in the imaging process, affecting the image quality. In order to make up for this problem, more complex optical elements need to be used for compensation. However, this will increase the cost and structural complexity, which is not conducive to the large-scale production and application of head-mounted devices; when d1m / F1 is greater than 2.3, it will also have adverse effects. Larger d1m means that the light may spread to the edge area when passing through P1, and these areas may not be effectively utilized or collected. In this way, the light reaching the image plane will be reduced, thereby affecting the imaging brightness. In addition, the larger ratio of d1m to F1 may also cause the increase of aberration. Light is more susceptible to various aberrations such as spherical aberration, coma, astigmatism, etc. when passing through a larger aperture. These aberrations will reduce the imaging quality, making the image blurred and distorted. Moreover, too large d1m may mean redundancy in design, increasing the volume, weight and cost of the system, but not bringing substantial performance improvement.

[0074] It is worth mentioning that when the optical system satisfies the above relationship, the following effects can be achieved: first, the focal length of the optical system is effectively controlled, the field of view of the system is constrained, and the system satisfies the characteristics of the large field of view of the VR lens. A large field of view can bring a more immersive experience to the user, as if they were in a virtual world. Second, by constraining the size of the lens barrel P0, the size of the lens barrel P0 is as small as possible under the premise of ensuring the processability of the lens barrel P0, thereby reducing the size of the whole machine. This is very important for head-mounted devices, because smaller size can improve the comfort and portability of wearing. Third, by controlling the effective focal length of the first lens E1, it is beneficial to control the shape of the first lens E1, thereby determining the position conducive to the attachment of the RP film (reflective polarizing film, i.e. the reflective polarizing element S1). The attachment of the RP film can further improve the performance of the optical system, such as reducing reflection and improving contrast. Finally, by controlling the distance from the object side end face of the lens barrel P0 to the spacer element P1, the thickness of the front end face of the lens barrel P0 and the mechanism diameter thickness of the spacer element P1 can be controlled. This is beneficial to the molding of the lens barrel P0 and the lens, improves production efficiency and quality. At the same time, it is also beneficial to control the size of the components and reduce costs.

[0075] It can be understood that the optical system of the head-mounted device of the preferred embodiment of the present application achieves excellent performance and effect through reasonable design and parameter control. It not only meets the demand of large field of view of VR lens, but also reduces the size of the whole machine under the premise of ensuring the imaging quality, improves the comfort and portability of wearing.

[0076] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.30<EP12 / (d1s-2*DT11)<2.55, wherein EP12 is the interval distance between the image side face of the first spacer element P1 and the object side face of the second spacer element P2 in the direction along the optical axis, d1s is the inner diameter of the object side face of the spacer element P1 perpendicular to the plane of the optical axis, and DT11 is the maximum effective radius of the object side face S3 of the first lens. It is worth mentioning that in the preferred embodiment of the present application, the setting of the above technical condition parameter range can effectively control the shape of the first lens E1, reduce the molding difficulty. At the same time, it can also control the interval of the first spacer element P1 and the second spacer element P2, which is beneficial to reduce the body height and realize the miniaturization of the VR lens.

[0077] In other words, the preferred embodiment of the present application can effectively control the shape of the first lens E1, reduce its molding difficulty by reasonably setting the maximum effective radius of the object side S3 of the first lens, the interval distance of the first interval element P1 and the second interval element P2, which is of great significance to improve production efficiency and reduce cost. In addition, it can be understood that by controlling the interval of the two interval elements, the body height of the optical system can be reduced, which is very important for head-mounted devices, because it can make the device more portable and comfortable, and it is more convenient to wear. In addition, by controlling the inner diameter of the object side end of the first interval element P1, the size of the optical system can be further reduced, which is beneficial to realize the miniaturization of the VR lens, and make the device more portable, convenient for users to carry and use.

[0078] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 2.0 < (D1s-d1m) / |SAG11|≤12.6, wherein d1m represents the inner diameter of the image side of the first interval element P1 perpendicular to the plane of the optical axis, which determines the range of light that can enter the optical system through the first interval element P1. A smaller inner diameter can limit too much light from entering, preventing overexposure caused by excessive light flux; while a larger inner diameter may allow more light to enter the system, which needs to be carefully adjusted to avoid underexposure caused by insufficient light flux. D1s is the outer diameter of the object side of the first interval element P1 perpendicular to the plane of the optical axis. It can be understood that this outer diameter size together with the inner diameter defines the overall size of the first interval element P1. A larger outer diameter can provide more space for the optical system to arrange other elements, but at the same time it may also increase the size of the whole machine, affecting the portability of the device. Therefore, it is necessary to reasonably control the size of the outer diameter under the premise of ensuring the optical performance. SAG11 is the on-axis distance between the intersection of the object side S3 of the first lens and the optical axis and the effective radius vertex of the object side S3 of the first lens. This distance reflects the shape and curvature of the first lens, which plays an important role in the refraction and focusing of light, so by adjusting the value of SAG11, the optical performance of the first lens E1 can be changed, thereby affecting the imaging quality of the entire optical system.

[0079] It is worth mentioning that in the preferred embodiment of the present application, the ratio of (D1s-d1m) / |SAG11| in the above relationship reflects the relationship between the size of the first spacer element P1 and the shape of the first lens E1. When this ratio changes between 2.0 and 12.6, it means that the size of the first spacer element P1 and the shape of the first lens E1 can be adjusted within a certain range to meet different optical design requirements. For example, when a larger field of view is needed, the values of D1s and d1m can be appropriately increased, while the value of SAG11 is reduced, to increase the incidence angle and range of light. When higher resolution is needed, the values of D1s and d1m can be reduced, while the value of SAG11 is increased, to improve the focusing accuracy and image quality of light.

[0080] Firstly, in the above relationship of the preferred embodiment of the present application, d1m limits the amount of light that can enter the optical system. By adjusting the value of d1m, the optical system can receive the appropriate amount of light under different lighting conditions, avoiding overexposure or underexposure. For example, in strong light environment, the value of d1m can be reduced to reduce the amount of light entering the system, preventing the image from being too bright. In weak light environment, the value of d1m can be appropriately increased to increase the collection of light and improve the brightness of the image. Therefore, the control of light flux can improve the quality and stability of the image, so that the head-mounted device can provide clear and accurate images in different environments. Secondly, in the above relationship of the preferred embodiment of the present application, D1s does not directly affect the light flux, but it defines the overall size of the first spacer element P1 together with d1m. Reasonable control of the values of D1s and d1m can make the size of the first spacer element P1 match other optical elements and the overall structure, thereby helping to constrain the size of the whole machine and improve the compactness of the system. For head-mounted devices, compact design can make the device more portable and comfortable, and it is more convenient to wear. At the same time, smaller size is also conducive to the carrying and storage of the device, improving the user experience.

[0081] In addition, in the above relationship of the preferred embodiment of the present application, the optical system of the head-mounted device allows (D1s-d1m) / |SAG11| to change within a certain range, providing great flexibility for optical design. Designers can adjust the size and position of the spacer element and lens according to specific requirements such as focal length, field of view, aperture size, etc., to achieve the best optical performance. For example, when adjusting the focal length, the curvature of the first lens E1 and the position of the first spacer element P1 can be changed. When changing the field of view, the values of D1s and d1m can be adjusted to change the incidence angle and range of light. This flexibility makes the optical system adapt to different application scenarios and user needs, improving the universality and competitiveness of the product.

[0082] Therefore, when the optical system of the head-mounted device of the preferred embodiment of the present application satisfies the following relationship: 2.0 < (D1s-d1m) / |SAG11|≤12.6, by controlling the size of the first spacing element P1 and the shape of the first lens, the control of light flux, the constraint of the overall size, and the flexibility of optical design are achieved, which facilitates to provide high-quality images and comfortable use experience.

[0083] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.80 < EP01 / CT1 < 1.25, wherein EP01 is the interval distance from the lens barrel object side end surface P01 to the object side surface of the first spacing element P1 in the optical axis direction, and CT1 is the center thickness of the first lens E1 in the optical axis.

[0084] It is worth mentioning that EP01 not only affects the structural layout of the front end of the lens barrel, but also is closely related to the optical performance. A suitable EP01 value can ensure that the light propagates at the best angle and path when entering the optical system, improving the imaging quality. Specifically, the size of EP01 affects the wall thickness of the front end of the lens barrel. If EP01 is too small, the wall thickness of the front end of the lens barrel may be insufficient, resulting in reduced strength and stability of the lens barrel. Conversely, if EP01 is too large, the wall thickness of the front end of the lens barrel may be too large, increasing the weight and volume of the lens barrel, which is not conducive to the miniaturization and lightweight design of the device.

[0085] It is worth mentioning that the change of the center thickness of the first lens E1 will cause the change of the curvature and surface shape of the first lens. Therefore, by controlling CT1, the shape of the first lens E1 can be accurately adjusted to meet different optical design requirements.

[0086] When the value of CT1 increases, the central part of the first lens E1 becomes thicker, thereby changing the curvature of the lens, which can affect the refraction and focusing of light, and further adjust the imaging effect of the optical system. It can be understood that in the preferred embodiment of the present application, by adjusting the value of CT1, the surface shape of the first lens E1 can be made more smooth and regular, providing a good basis for the attachment of the RP film. In this way, not only the firmness of the RP film can be improved, but also the optical performance of the optical system can be ensured to be stable and reliable.

[0087] By controlling the distance EP01 from the mirror barrel object side end surface P01 to the spacing element P1, the mirror barrel front end surface wall thickness and the structure diameter thickness of the first spacing element P1 can be effectively controlled. During the forming of the mirror barrel P0, a suitable front end surface wall thickness can ensure that the mirror barrel has sufficient strength and rigidity to withstand the pressure of the internal optical elements and external impact. At the same time, a reasonable structure diameter thickness of the first spacing element P1 can ensure that the spacing element can be stably installed in the mirror barrel, providing reliable support and separation for the lens group. For example, by adjusting the value of EP01, the mirror barrel front end surface wall thickness and the structure diameter thickness of the first spacing element P1 can be optimized, thereby improving the forming quality of the mirror barrel and the lens. In this way, the defect rate and the waste rate in the production process can be reduced, and the production cost can be reduced.

[0088] In this preferred embodiment of the present application, by controlling the ratio of EP01 and CT1, the overall size of the first spacing element P1 and the lens can be constrained, that is, by reasonably adjusting these two parameters, the optical system can be more compact, the volume and weight of the device can be reduced, and the portability and use convenience of the device can be improved.

[0089] As an example, in one specific example of the present application, by optimizing the values of EP01 and CT1, the size of the mirror barrel and the lens can be made more compact, thereby meeting the needs of different application scenarios. In some occasions with high space requirements, such as head-mounted display devices, miniature cameras, etc., a small optical system can provide a better user experience.

[0090] When the optical system of the head-mounted device of the preferred embodiment of the present application satisfies: 0.80 < EP01 / CT1 < 1.25, that is, by controlling the center thickness CT1 of the first lens E1 and the distance EP01 from the mirror barrel object side end surface P01 to the spacing element P1, the shape of the first lens E1 can be accurately controlled, and the position conducive to RP film attachment can be determined; at the same time, the mirror barrel front end surface wall thickness and the structure diameter thickness of the spacing element P1 can also be controlled, which is conducive to the forming of the mirror barrel and the lens; in addition, the overall size of the spacing element and the lens can also be constrained, and the miniaturization and lightweight design of the optical system can be realized.

[0091] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 1.4 ≤ L / EP02 < 1.7, wherein L is the maximum horizontal distance from the mirror barrel object side end surface P01 to the mirror barrel image side end surface P02 along the optical axis direction, and EP02 is the spacing distance from the mirror barrel object side end surface P01 to the second spacing element P2 object side surface along the optical axis direction.

[0092] It is worth mentioning that by limiting the ratio between L and EP02 in the range of 1.4≤L / EP02<1.7, the relative position between the lens barrel P0 and the second spacer element P2 can be ensured to be reasonable. That is, when designing the optical system, the distance between the lens barrel and the spacer element can be accurately controlled to avoid spatial conflicts or waste. For example, if the ratio of L and EP02 is too large, it may cause the distance between the lens barrel and the spacer element to be too long, wasting space and increasing the volume of the optical system; if the ratio is too small, it may cause the distance between the lens barrel and the spacer element to be too short, causing the light to be blocked and affecting the imaging quality. Therefore, by accurately controlling the distance between the lens barrel and the spacer element, the best optical performance can be achieved in a limited space to meet the high requirements of users on optical equipment.

[0093] In addition, by reasonably adjusting the ratio of L and EP02, the propagation of light in the optical system can be smoother, reducing the scattering and loss of light and improving the clarity and contrast of imaging. In addition, the field of view, focal length and other performance indicators of the optical system can also be optimized to meet the needs of different application scenarios. By optimizing the positional relationship between the lens barrel and the spacer element, the volume and weight of the optical system can be minimized under the premise of meeting the optical performance requirements, thereby reducing the amount of materials used. In mass production of optical equipment, by accurately controlling the ratio of L and EP02, standardized production can be achieved, production efficiency can be improved, and production costs can be reduced. At the same time, the scrap rate can be reduced, and the quality and reliability of the product can be improved.

[0094] When the optical system of the head-mounted device of the preferred embodiment of the present application satisfies the technical feature of 1.4≤L / EP02<1.7, by limiting the ratio between L and EP02, the relative position between the lens barrel P0 and the spacer element P2 can be ensured to be reasonable, avoiding spatial conflicts or waste; optimizing the positional relationship between the lens barrel and the spacer element can improve the performance of the optical system without increasing excessive costs; reasonable layout also helps to reduce material consumption and manufacturing costs.

[0095] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.15<CP1 / (CT1+T12)<0.80, where CP1 is the maximum thickness of the first spacer element P1 along the optical axis, CT1 is the central thickness of the first lens E1 on the optical axis, and T12 is the air gap between the first lens E1 and the second lens E2 on the optical axis.

[0096] In this preferred embodiment of the present application, by limiting the ratio between CP1 and (CT1+T12) within the range of 0.15<CP1 / (CT1+T12)<0.80, it helps to ensure the compactness of the optical system. This inequality requires that the thickness of the first spacer element P1 cannot be too large to occupy too much space, nor too small to ensure its structural stability and functionality. This balanced design can make the optical system achieve the best performance in a limited space, meeting the demand of miniaturization and portability of modern optical equipment. For example, when designing a small optical system such as a head-mounted display device or a miniature camera, compactness is a key consideration. By reasonably controlling the parameters of CP1, CT1 and T12, the optical system can be made more compact and portable for carrying and using.

[0097] It is worth mentioning that although this inequality is directly related to the ratio of physical dimensions, it indirectly affects the imaging quality of the optical system. The thickness of the first spacer element P1, the central thickness of the lens, and the air gap between the lenses are all important factors that affect the light propagation path and aberration. By optimizing the ratio of these parameters, aberrations such as spherical aberration, coma, and astigmatism can be reduced, thereby improving the clarity and resolution of the image.

[0098] Spherical aberration is an aberration caused by the different focusing abilities of different wavelengths of light by the lens. By reasonably adjusting the parameters of CP1, CT1 and T12, the light can be more uniformly focused when passing through the lens and the spacer element, reducing the influence of spherical aberration. Coma is an aberration caused by the uneven refraction of light when passing through the edge of the lens. By optimizing the shape of the lens and the position of the spacer element, the generation of coma can be reduced. Astigmatism is an aberration caused by the different focusing abilities of light in different directions. By adjusting the air gap between the lenses and the thickness of the spacer element, the propagation of light in different directions can be more uniform, reducing the influence of astigmatism.

[0099] It can be understood that these parameters can be adjusted according to specific needs (such as focal length, field of view angle, aperture size, etc.) to achieve the best optical performance. For example, in designs requiring longer focal length or larger field of view angle, it may be necessary to increase the air gap T12 between the lenses, while appropriately adjusting the thickness CP1 of the first spacer element P1 to maintain the ratio within a reasonable range.

[0100] If a longer focal length is required, it is generally necessary to increase the distance between the lenses to achieve a more distant focus of light. In this case, the value of T12 can be appropriately increased, while the thickness of CP1 is adjusted to ensure the compactness and stability of the optical system. If a larger field of view angle is required, the shape and position of the lens, as well as the thickness and position of the spacer element, need to be optimized to ensure that light can enter the optical system at a wider angle and form a clear image on the imaging surface.

[0101] In addition, the size of the aperture also affects the performance of the optical system. A larger aperture can allow more light into the optical system, improving the brightness and contrast of the image, but it can also increase aberrations. By properly adjusting the parameters of CP1, CT1 and T12, the best imaging effect can be achieved under different aperture sizes.

[0102] When the optical system of the head-mounted device of the preferred embodiment of the present application satisfies: 0.15 < CP1 / (CT1+T12) < 0.80, by limiting the ratio of the thickness of the first spacer element P1 to the sum of the central thickness of the first lens E1 and the air gap of the first lens E1 and the second lens E2 on the optical axis, the compactness of the optical system can be ensured, the imaging quality can be improved, and different design requirements can be met. Designers can adjust these parameters reasonably according to specific application scenarios and performance requirements to achieve the best optical performance.

[0103] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 1.4 < CP2 / T23 < 6.2, where CP2 is the maximum thickness of the second spacer element P2 along the optical axis, and T23 is the air gap of the second lens E2 and the third lens E3 on the optical axis.

[0104] In wearable electronic devices, compactness is an important design goal. In the preferred embodiment of the present application, by limiting the ratio of CP2 to T23 to be within the range of 1.4 < CP2 / T23 < 6.2, the thickness of the second spacer element P2 and the air gap between the two lenses (the second lens E2 and the third lens E3) can be effectively controlled, thereby maintaining the compactness of the system. When the ratio is within this range, it can avoid the second spacer element P2 being too thick and occupying too much space, and it can also prevent it from being too thin and unable to provide sufficient support and adjustment space. At the same time, a suitable air gap also helps to optimize the propagation of light, reduce unnecessary space waste, and enable the optical system to achieve the best performance in a limited space.

[0105] It is worth mentioning that the thickness of the second spacer element P2 and the air gap between the second lens E2 and the third lens E3 directly affect the layout of the optical elements. By limiting the ratio of CP2 to T23, the present application can ensure the compactness of the system while leaving enough space for other optical elements and achieving a reasonable layout.

[0106] The second spacing element P2 not only separates the optical elements in the optical system, but also needs to provide certain structural support for the optical elements. A suitable thickness can ensure that the second spacing element P2 has sufficient strength and stability to withstand the weight of the optical elements and external pressure. At the same time, a certain thickness also provides space for adjusting the position and angle of the optical elements, facilitating the calibration and optimization of the optical system.

[0107] Therefore, when the optical system of the head-mounted device of the preferred embodiment of the present application satisfies 1.4 < CP2 / T23 < 6.2, that is, by reasonably controlling the thickness of the second spacing element P2 and the ratio of the air gap between the second lens E2 and the third lens E3, the optical elements can be reasonably arranged while maintaining the compactness of the system, providing sufficient structural support and adjustment space for the optical system, thereby improving the performance and stability of the optical system.

[0108] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 2.05 < d0m / DT32 < 3.30, where d0m is the inner diameter of the lens barrel image side surface P02 perpendicular to the plane of the optical axis, and DT32 is the maximum effective radius of the third lens image side surface S8.

[0109] It is worth mentioning that aberrations in the optical system are important factors affecting the imaging quality; spherical aberration will cause light rays to not accurately focus on a point when passing through the lens, resulting in blurred imaging; coma will cause light rays to form a comet-like spot on the imaging plane; astigmatism will cause light rays to focus differently in different directions, resulting in image distortion; field curvature will cause the imaging plane to be a curved surface rather than a flat surface; distortion will cause the shape of the image to be distorted. In the preferred embodiment of the present application, by adjusting the ratio of the inner diameter of the lens barrel image side surface P02 perpendicular to the plane of the optical axis to the maximum effective radius of the third lens image side surface S8 within the range of 2.05 < d0m / DT32 < 3.30, these aberrations can be controlled to a certain extent.

[0110] As an example, when the ratio is appropriate, the propagation path of light rays in the optical system can be optimized, reducing the generation of spherical aberration and coma. At the same time, astigmatism and field curvature can also be adjusted to make the imaging plane more flat. In addition, a reasonable ratio can also control distortion to make the shape of the image more accurate. By controlling these aberrations, the clarity and resolution of the image can be improved, providing users with a better visual experience.

[0111] It can be understood that a larger inner diameter d0m allows more light to enter the system, and more light flux can improve the brightness of the imaging, making the image clearer and more visible. However, an excessively large inner diameter will also increase the complexity and cost of the system. On the one hand, a larger barrel requires more materials and manufacturing processes, increasing production costs. On the other hand, a large-diameter barrel can introduce more stray light, which requires additional optical elements to eliminate these stray lights, increasing the complexity of the system.

[0112] By setting the proportional relationship between d0m and DT32, unnecessary waste and complexity can be avoided while ensuring sufficient light flux. When the proportion is within a suitable range, better light flux can be obtained without significantly increasing the cost and complexity of the system, improving the imaging quality.

[0113] Therefore, when the optical system of the head-mounted device of the preferred embodiment of the present application satisfies: 2.05 < d0m / DT32 < 3.30, that is, by reasonably adjusting the proportion of the barrel inner diameter and the effective radius of the lens, it can play an important role in controlling aberration and balancing light flux, improving the imaging quality of the optical system, and meeting the needs of different application scenarios.

[0114] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 35.05 < d2m / |SAG22| < 59.35, where d2m is the inner diameter of the second spacer element P2 perpendicular to the plane of the optical axis, and SAG22 is the on-axis distance between the intersection of the second lens image side S6 and the optical axis to the effective radius vertex of the second lens image side S6.

[0115] It is worth mentioning that VR systems usually require a larger field of view to provide a more immersive experience. In the preferred embodiment of the present application, by adjusting the proportion between d2m and SAG22 within the range of 35.05 < d2m / |SAG22| < 59.35, the propagation path of the light and the focal length of the system can be affected, thereby optimizing the field of view to a certain extent. When the proportion is appropriate, the light can propagate in the optical system in a more reasonable way, so that the field of view can meet the user's demand for immersive experience, and at the same time, the aberration will not be too large to affect the imaging quality.

[0116] The field of view can be optimized by adjusting the inner diameter d2m of the spacer element P2 and the SAG22 value of the second lens E2. If the field of view is too small, the user will feel that the field of view is narrow when using the VR system, and the sense of immersion is not enough; if the field of view is too large, it may cause image distortion and increase in aberration, affecting the imaging quality. By reasonably adjusting this proportion, the field of view can be increased as much as possible while ensuring the imaging quality, improving the user's experience.

[0117] By adjusting the ratio of d2m and SAG22, the size and weight of the optical system can be optimized while ensuring imaging quality. For example, the size of the spacer element P2 can be reduced by reducing the value of d2m, or the shape and curvature of the second lens E2 can be changed by adjusting the value of SAG22, thereby reducing the volume and weight of the entire optical system. By reasonably adjusting this ratio, the propagation path of light can be optimized, the generation of aberrations can be reduced, and the imaging quality can be improved.

[0118] When the optical system of the head-mounted device of the preferred embodiment of the present application satisfies: 35.05 < d2m / |SAG22| < 59.35, that is, by adjusting the ratio between the inner diameter of the spacer element P2 and the SAG22 value of the second lens image side S6, the field of view angle can be optimized, the relationship between system size and performance can be balanced, and the imaging quality and user experience of the VR system can be improved.

[0119] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.20 < (d0m-d0s) / f < 1.30, where d0s is the inner diameter of the lens barrel object side P01 perpendicular to the plane of the optical axis, and d0m is the inner diameter of the lens barrel image side P02 perpendicular to the plane of the optical axis.

[0120] It is worth mentioning that the difference between the object side and image side inner diameters of the lens barrel P0 (d0m-d0s) directly affects the amount of light that the system can collect. A larger difference means that more light can enter the system, thereby improving light collection efficiency.

[0121] Therefore, in the preferred embodiment of the present application, by setting the ratio relationship 0.20 < (d0m-d0s) / f < 1.30, the light collection efficiency can be ensured while avoiding the problem of excessive divergence or inaccurate focusing of light.

[0122] By adjusting the ratio between the difference between the object side and image side inner diameters of the lens barrel and the focal length, the propagation path of light and the imaging characteristics of the system can be affected, thereby optimizing the imaging quality to some extent. Different ratio relationships will cause changes in the refraction, reflection and focusing of light in the optical system, thereby affecting the clarity, contrast, color reproduction and other aspects of the imaging.

[0123] It is worth mentioning that in the preferred embodiment of the present application, by reasonably adjusting this ratio, the generation of aberrations such as spherical aberration, coma, astigmatism, etc. can be reduced. By optimizing the ratio between the difference between the inner diameters of the lens barrel and the focal length, the propagation path of light can be adjusted, the influence of these aberrations can be reduced, and the clarity and resolution of the imaging can be improved.

[0124] It can be understood that the proportional relationship between the difference of the inner diameters of the object side and the image side of the lens barrel and the focal length also relates to the overall size of the system. By reasonable adjustment, the size of the system can be minimized under the premise of ensuring performance. If the difference of the inner diameters is too large or the focal length is too long, it may cause the volume of the lens barrel to increase, which is not conducive to the miniaturization and portability of the system. By optimizing this proportional relationship, the size of the lens barrel can be reduced while meeting the requirements of light collection efficiency and imaging quality, making the optical system more compact. Therefore, by selecting appropriate lens materials and manufacturing processes, and optimizing the layout of the optical system, the size of the lens barrel can be reduced while ensuring imaging quality and light collection efficiency.

[0125] When the optical system of the head-mounted device of the preferred embodiment of the present application satisfies: 0.20<(d0m-d0s) / f<1.30, that is, by reasonably adjusting the proportional relationship between the difference of the inner diameters of the object side and the image side of the lens barrel and the focal length, the balance between light collection efficiency and focusing accuracy can be achieved, the imaging quality can be optimized, the system size can be controlled, and the needs of different application scenarios can be met.

[0126] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.95<d1m / (DT12*2)<1.20, where d1m is the inner diameter of the plane perpendicular to the optical axis of the image side of the first spacer element P1, and DT12 is the maximum effective radius of the image side S4 of the first lens.

[0127] In the preferred embodiment of the present application, by adjusting the proportional relationship between d1m and DT12 within the range of 0.95<d1m / (DT12*2)<1.20, the occurrence of aberration can be controlled to a certain extent. Reasonable proportioning can optimize the propagation path of light in the optical system, reduce the generation of aberration, and improve the clarity and accuracy of the image.

[0128] When the proportion is appropriate, the light can be more uniformly focused when passing through the first spacer element P1 and the first lens E1, reducing the influence of spherical aberration and coma. At the same time, astigmatism and field curvature can also be adjusted to make the imaging plane more flat. In addition, reasonable proportioning can also control distortion to make the shape of the image more accurate. By controlling aberration, the imaging quality of the optical system can be improved to provide users with clearer and more accurate images.

[0129] By optimizing the proportion of d1m and DT12, the size of the first spacer element P1 and the first lens E1 can be made more compact, thereby reducing the volume of the entire optical system. The size of the first spacer element P1 can be reduced by reducing the value of d1m, or the shape and size of the first lens E1 can be changed by adjusting the value of DT12.

[0130] It can be understood that a reasonable proportion relationship helps to ensure that the relative position relationship between each element in the system is reasonable, thereby improving the overall performance, stability and reliability of the system. The positional relationship between the first spacing element P1 and the first lens E1 has an important influence on the propagation of light and the imaging quality. If the positional relationship between them is unreasonable, it may cause scattering, reflection and inaccurate focusing of light, affecting the imaging quality. Therefore, by adjusting the proportion of d1m and DT12, the relative position of the first spacing element P1 and the first lens E1 can be made more reasonable, the propagation path of light can be optimized, and the performance and stability of the system can be improved.

[0131] Optimizing the proportion relationship of d1m and DT12 also helps to reduce the mass of the whole machine. In an optical system, the mass of each element affects the weight and portability of the entire device. By reducing the size and weight of the first spacing element P1 and the first lens E1, the mass of the entire optical system can be reduced, making the device more portable and easy to carry and use.

[0132] When the optical system of the head-mounted device of the preferred embodiment of the present application satisfies: 0.95 < d1m / (DT12*2) < 1.20, i.e. by adjusting the proportion relationship between the inner diameter of the first spacing element P1 and the effective radius of the first lens image side S4, the occurrence of aberration can be controlled, the image quality can be improved, the system size can be optimized to realize miniaturization design, the relative position of the elements can be ensured to be reasonable to improve the performance and stability of the system, and the mass of the whole machine can be reduced to improve the portability. Designers can reasonably adjust this proportion relationship according to specific application requirements and performance requirements to achieve the best optical performance and design goal.

[0133] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.95 < (CP1+E12+CP2) / (T12+CT2+T23) < 2.80, wherein CP1 is the maximum thickness of the first spacing element P1 along the optical axis, CP2 is the maximum thickness of the second spacing element P2 along the optical axis, T12 is the air gap of the first lens E1 and the second lens E2 on the optical axis, T23 is the air gap of the second lens E2 and the third lens E3 on the optical axis, and CT2 is the center thickness of the second lens E2 on the optical axis.

[0134] Specifically, in this preferred embodiment of the present application, by adjusting the ratio relationship 0.95<(CP1+E12+CP2) / (T12+CT2+T23)<2.80, the overall size of the system can be minimized under the premise of ensuring system performance. Smaller intervals and thicknesses mean that the system can be more compact, reducing space occupation. For wearable devices such as VR headsets, this can improve the comfort and portability of wearing. Users will not feel heavy and oppressive when using, and it is also more convenient to carry and store.

[0135] In addition, in the present application, by adjusting the relative size and interval between the spacer element P and the lens, the optical path length can be controlled. Reasonable optical path length helps to reduce the loss and distortion of light during propagation, thereby optimizing the imaging quality. If the optical path length is too long, the light may be scattered, absorbed, etc. during propagation, resulting in reduced imaging brightness and clarity; if the optical path length is too short, the optical performance of the lens may not be fully utilized, which will also affect the imaging quality.

[0136] It can be understood that when designing a VR optical system, the relationship between system performance and cost needs to be balanced. Smaller intervals and thicknesses may mean lower manufacturing costs, as the amount of material used and the complexity of the manufacturing process can be reduced. However, it may also have some impact on system performance. By setting this ratio relationship, manufacturing costs can be minimized under the premise of ensuring that system performance meets requirements.

[0137] When the optical system of the head-mounted device of this preferred embodiment of the present application satisfies 0.95<(CP1+E12+CP2) / (T12+CT2+T23)<2.80, i.e. by adjusting this ratio relationship, the system size can be reduced, the portability and comfort can be improved, the optical path length can be controlled, the imaging quality can be optimized, the system performance and cost can be balanced, and a more efficient and economical design can be achieved under the premise of ensuring system performance.

[0138] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: -4.85<f23 / R5*(CP2 / T23)<9.3, where f23 is the combined focal length of the second lens E2 and the third lens E3, R5 is the radius of curvature of the object side S7 of the third lens, and T23 is the air gap of the second lens E2 and the third lens E3 on the optical axis.

[0139] Specifically, in the preferred embodiment of the present application, the ratio between the focal length f23 and the radius of curvature R5 of the object side surface of the third lens E3 directly affects the imaging performance of the system, so the preferred embodiment of the present application can control the focusing characteristics of light by adjusting this ratio. The ratio between the thickness CP2 of the second spacer element P2 and the air gap T23 also plays a similar role. They jointly affect the propagation path of light and the imaging effect. By reasonably adjusting these two ratios, the propagation of light in the optical system can be optimized, the generation of aberrations can be reduced, and the imaging quality can be improved.

[0140] It can be understood that smaller spacing and thickness mean that the system can be more compact, reducing the size and weight of the system. This is very important for VR devices, because a lightweight device can improve the comfort and portability of wearing. By reasonably adjusting the ratio of CP2 and T23, the thickness of the spacer element P2 and the air gap can be reduced, so that the optical system is more compact.

[0141] Different VR optical systems may have different design requirements and goals. Some systems may focus more on imaging quality, while others may focus more on the portability and cost-effectiveness of the system, so by adjusting the ratio -4.85 < f23 / R5*(CP2 / T23) < 9.3, VR optical systems that meet different requirements can be designed.

[0142] When the optical system of the head-mounted device of the preferred embodiment of the present application satisfies -4.85 < f23 / R5*(CP2 / T23) < 9.3, i.e. by adjusting this ratio, the focusing characteristics of light can be controlled, the imaging quality can be optimized; the size and weight of the system can be reduced, the comfort and portability of wearing can be improved; different design requirements can be met, and a better VR optical system can be designed.

[0143] Further, in one specific example of the present application, the optical system of the head-mounted device further satisfies the following condition: 0.05 < CP2 / |SAG31| < 0.30, where SAG31 is the on-axis distance between the intersection of the object side surface S7 of the third lens and the optical axis and the effective radius vertex of the object side surface S7 of the third lens.

[0144] Specifically, in this preferred embodiment of the present application, by limiting the ratio of CP2 to |SAG31| within the range of 0.05 < CP2 / |SAG31| < 0.30, the degree of tilt and decentration of the lens can be indirectly controlled. If the lens has a large tilt or decentration, the light rays will deviate from the ideal path when passing through the lens, causing imaging blur, distortion, or color difference, etc., thereby seriously affecting the imaging effect. In addition, the tilt and decentration of the lens can also cause the stability of the optical system to decrease, which is easily affected by external factors such as vibration during use, further reducing the imaging quality. By reasonably controlling this ratio range, the position of the third lens E3 on the optical axis can be ensured to be accurate, reducing the occurrence of tilt and decentration, thereby ensuring the imaging quality and stability of the system.

[0145] It is worth mentioning that although this inequality does not directly involve the overall size of the system, by reasonably controlling the ratio relationship of CP2 and SAG31, the size of some elements in the system can be minimized as much as possible under the premise of ensuring system performance. For wearable devices such as VR headsets, the compactness of the system is crucial. Smaller volume and weight can improve the comfort of wearing and reduce the burden on the user's head. At the same time, it is also convenient to carry and use, increasing the portability of the device. For example, when designing a VR optical system, the ratio relationship of CP2 and SAG31 can be reasonably controlled to make the optical system more compact and lightweight, improving the user's experience.

[0146] In the manufacturing process of the optical system, the size and shape of each element need to be accurately controlled to ensure that the performance of the system meets the design requirements. The ratio range of CP2 and SAG31 provides a specific target for size control in the manufacturing process, which helps to improve manufacturing precision. At the same time, during the assembly process of the system, the positions of the lenses and the thickness of the spacing elements can also be adjusted according to this ratio range to ensure the accurate relative positions between the elements.

[0147] Improving manufacturing and assembly precision can reduce the performance degradation caused by manufacturing and assembly errors. If there are large errors in the manufacturing and assembly process, the imaging quality of the optical system may decrease, or even cannot work normally. By strictly controlling the ratio relationship of CP2 and SAG31, the influence of these errors can be effectively reduced, improving the performance stability of the system.

[0148] When the optical system of the head-mounted device of the preferred embodiment of the present application satisfies: 0.05<CP2 / |SAG31|<0.30, that is, by reasonably controlling the proportional relationship between the thickness CP2 of the spacer element P2 and the on-axis distance SAG31 of the third lens object side, the tilt and eccentricity of the lens can be indirectly controlled, the imaging quality and stability are ensured, the compactness design of the system is realized, the wearing comfort and portability are improved, clear guidance is provided for the manufacturing and assembly process, the manufacturing and assembly precision is improved, and the performance degradation is reduced.

[0149] As Figures 1 to 9 The optical system of the head-mounted device of the preferred embodiment of the present application is shown in nine different specific embodiments, wherein the optical elements in the optical system in embodiment one, embodiment two and embodiment three have the same optical properties; wherein the optical elements in the optical system in embodiment four, embodiment five and embodiment six have the same optical properties; wherein the optical elements in the optical system in embodiment seven, embodiment eight and embodiment nine have the same optical properties, such as the surface type, curvature radius, thickness material and the like of each surface, the difference lies in the above relationship.

[0150] Figures 10A to 10C The on-axis chromatic aberration curve, the astigmatism curve and the distortion curve of the optical system of the head-mounted device of the first to third preferred embodiments of the present application are shown; Figures 11A to 11C The on-axis chromatic aberration curve, the astigmatism curve and the distortion curve of the optical system of the fourth to sixth preferred embodiments of the present application are shown; Figures 12A to 12C The on-axis chromatic aberration curve, the astigmatism curve and the distortion curve of the optical system of the seventh to ninth preferred embodiments of the present application are shown; Figure 13 The size of the optical system of the head-mounted device of the first preferred embodiment of the present application is shown; Figure 14 The size of the first lens of the optical system of the head-mounted device of the first preferred embodiment of the present application is shown.

[0151] Specifically, Table 1 is the optical parameters of each optical element in embodiment one, embodiment two and embodiment three of the present application; and Table 2 is the surface parameters of the lens of each optical element in embodiment one, embodiment two and embodiment three of the present application.

[0152] Table 1 is the optical parameters of each optical element in embodiment one, embodiment two and embodiment three

[0153]

[0154] Table 2 is the surface parameters of the lens of each optical element in embodiment one, embodiment two and embodiment three of the present application.

[0155] Surface 3 4 5 6 7 A4 -2.3109E-07 9.3349E-07 1.0325E-05 2.1320E-06 1.0605E-05 A6 5.5331E-10 -4.2345E-10 1.7868E-08 1.5578E-08 -1.1391E-07 A8 1.7081E-12 9.4844E-12 2.6550E-11 3.2325E-11 1.8865E-10 A10 -3.3433E-15 -1.6437E-14 3.1407E-14 7.2565E-15 -1.5117E-13 A12 0.0000E+00 1.1039E-17 -7.4441E-17 -1.7271E-16 6.9996E-17 A14 0.0000E+00 -2.7319E-21 0.0000E+00 0.0000E+00 -1.9705E-20 A16 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 3.3338E-24 A18 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 -3.1204E-28 A20 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 1.2428E-32

[0156] Table 3 is the optical parameter of each optical element in the fourth embodiment, the fifth embodiment and the sixth embodiment of the present application; Table 4 is the surface parameter of the lens of each optical element in the fourth embodiment, the fifth embodiment and the sixth embodiment of the present application.

[0157] Table 3 is the optical parameter of each optical element in the fourth embodiment, the fifth embodiment and the sixth embodiment of the present application; Table 4 is the surface parameter of the lens of each optical element in the fourth embodiment, the fifth embodiment and the sixth embodiment of the present application.

[0158]

[0159] Table 4 is the surface parameter of the lens of each optical element in the fourth embodiment, the fifth embodiment and the sixth embodiment of the present application; Table 4 is the surface parameter of the lens of each optical element in the fourth embodiment, the fifth embodiment and the sixth embodiment of the present application.

[0160] Surface 3 4 5 6 7 8 A4 -1.7775E-07 0.0000E+00 0.0000E+00 3.9893E-06 -4.2990E-07 -1.3549E-06 A6 -1.5376E-09 0.0000E+00 0.0000E+00 2.2594E-08 8.5416E-09 -8.2555E-10 A8 -3.8081E-13 0.0000E+00 0.0000E+00 -3.9809E-10 4.3746E-11 4.4041E-11 A10 -3.2614E-16 0.0000E+00 0.0000E+00 2.1865E-12 2.6695E-15 -2.3115E-15 A12 7.3703E-19 0.0000E+00 0.0000E+00 -5.8925E-15 -1.1718E-18 -4.1926E-18 A14 0.0000E+00 0.0000E+00 0.0000E+00 9.1037E-18 0.0000E+00 0.0000E+00 A16 0.0000E+00 0.0000E+00 0.0000E+00 -8.3108E-21 0.0000E+00 0.0000E+00 A18 0.0000E+00 0.0000E+00 0.0000E+00 4.1898E-24 0.0000E+00 0.0000E+00 A20 0.0000E+00 0.0000E+00 0.0000E+00 -9.0012E-28 0.0000E+00 0.0000E+00

[0161] Table 5 is the optical parameter of each optical element in the seventh embodiment, the eighth embodiment and the ninth embodiment of the present application; Table 6 is the surface parameter of the lens of each optical element in the seventh embodiment, the eighth embodiment and the ninth embodiment of the present application.

[0162] Table 5 is the optical parameter of each optical element in the seventh embodiment, the eighth embodiment and the ninth embodiment of the present application; Table 6 is the surface parameter of the lens of each optical element in the seventh embodiment, the eighth embodiment and the ninth embodiment of the present application.

[0163]

[0164] Table 6 is the surface parameter of the lens of each optical element in the seventh embodiment, the eighth embodiment and the ninth embodiment of the present application; Table 6 is the surface parameter of the lens of each optical element in the seventh embodiment, the eighth embodiment and the ninth embodiment of the present application.

[0165] Surface 3 4 5 6 7 8 A4 -4.2137E-08 0.0000E+00 -1.8579E-05 0.0000E+00 0.0000E+00 -2.9287E-05 A6 -1.4631E-09 0.0000E+00 7.0560E-09 0.0000E+00 0.0000E+00 1.4825E-07 A8 2.9789E-13 0.0000E+00 1.5033E-10 0.0000E+00 0.0000E+00 -2.2567E-10 A10 -3.3682E-14 0.0000E+00 1.2382E-13 0.0000E+00 0.0000E+00 1.7249E-13 A12 -3.9252E-17 0.0000E+00 -1.8394E-16 0.0000E+00 0.0000E+00 -7.3184E-17 A14 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 1.7134E-20 A16 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 -1.9295E-24 A18 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 4.1953E-29 A20 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 6.3544E-33

[0166] Table 7 shows the parameter characteristic data in the first embodiment (1) to the ninth embodiment (9) of the present application.

[0167] Table 7 shows the parameter characteristic data in the first embodiment (1) to the ninth embodiment (9) of the present application.

[0168]

[0169]

[0170] Table 8 shows the parameter characteristic data in the first embodiment (1) to the ninth embodiment (9) of the present application.

[0171] Table 8 shows the parameter characteristic data in the first embodiment (1) to the ninth embodiment (9) of the present application.

[0172] Example data 1 2 3 4 5 6 7 8 9 d1s 42.93 42.92 41.82 40.06 41.00 41.98 38.05 38.66 43.08 d1m 44.18 44.19 40.89 42.23 39.64 39.51 39.18 39.92 35.66 D1s 45.71 45.74 45.09 42.71 43.28 44.63 43.90 42.96 45.27 d2m 43.00 45.71 36.71 42.31 42.15 39.95 37.50 37.49 39.03 d0s 30.95 30.54 31.00 31.54 31.54 31.54 31.75 31.75 31.01 d0m 52.52 49.92 34.69 49.44 49.34 37.50 49.01 49.01 35.66 EP01 6.58 6.59 6.59 8.09 8.09 8.09 6.63 6.63 6.02 CP1 6.51 5.82 5.82 4.76 4.76 4.76 1.28 2.08 2.08 EP12 1.34 2.03 2.33 1.72 1.72 1.98 5.86 5.07 5.43 CP2 3.85 4.59 4.56 1.21 1.21 0.85 2.44 2.44 2.08 EP02 14.43 14.44 14.74 14.58 14.58 14.84 13.78 13.78 13.53 L 24.00 21.62 22.37 20.38 20.43 21.08 21.01 21.01 19.04

[0173] Table 9 shows the conditional data in the first embodiment (1) to the ninth embodiment (9) of the present application.

[0174] Table 9: Data for each condition in Examples 1-9

[0175] Conditional / Example 1 2 3 4 5 6 7 8 9 d1m / F1 2.29 2.29 2.12 1.53 1.43 1.43 2.16 2.20 1.97 L / f 1.39 1.25 1.29 0.92 0.93 0.96 1.22 1.22 1.11 EP12 / (d1s-2*DT11) 0.34 0.51 0.81 0.39 0.32 0.31 2.54 1.74 0.74 (D1s-d1m) / |SAG11| 10.71 10.86 12.60 2.41 2.07 2.41 5.60 4.12 2.10 EP01 / CT1 0.82 0.82 0.82 1.21 1.21 1.21 1.11 1.11 1.00 L / EP02 1.66 1.50 1.52 1.40 1.40 1.42 1.52 1.52 1.41 CP1 / (CT1+T12) 0.77 0.68 0.68 0.64 0.64 0.64 0.18 0.30 0.30 CP2 / T23 5.17 6.16 6.12 2.07 2.07 1.45 3.16 3.16 2.69 d0m / DT32 3.26 3.10 2.15 2.74 2.74 2.08 2.89 2.89 2.11 d2m / |SAG22| 54.38 57.80 46.42 59.30 59.08 56.00 35.10 35.09 36.53 (d0m-d0s) / f 1.25 1.12 0.21 0.81 0.81 0.27 1.00 1.00 0.27 d1m / (DT12*2) 1.13 1.13 1.05 1.16 1.09 1.08 1.08 1.10 0.98 (CP1+E12+CP2) / (T12+CT2+T23) 2.54 2.70 2.76 0.98 0.98 0.97 1.16 1.16 1.16 f23 / R5*(CP2 / T23) 7.76 9.25 9.19 -1.05 -1.05 -0.74 -4.81 -4.81 -4.10 CP2 / |SAG31| 0.23 0.28 0.28 0.07 0.07 0.05 0.14 0.14 0.12

[0176] According to another aspect of the present application, the present application further provides a head-mounted device, wherein the head-mounted device can be but is not limited to an AR device or a VR device, such as an AR(VR) glasses, wherein the head-mounted device comprises a head-mounted device body (not shown in the figures) and at least one optical system arranged on the head-mounted device body, the at least one optical system is carried on the head-mounted device body, the at least one optical system is as described in any of the above embodiments, which will not be repeated herein.

[0177] It will be understood by those skilled in the art that the embodiments of the present application described above and shown in the drawings are only examples and do not limit the present application. The purpose of the present application has been fully and effectively achieved. The function and structural principle of the present application has been demonstrated and explained in the embodiments, and the implementation of the present application can be any modification or change without departing from the principle.

Claims

1. An optical system of a head-mounted device, characterized by, Comprising: A lens barrel; A lens group, wherein the lens group includes a reflective polarizing element, a quarter-wave plate, a first lens, a second lens, and a third lens. Among them, the reflective polarizing element, the quarter-wave plate, and the first lens form an optical element group, and the optical element group has a positive optical power. The second lens has a positive optical power, the third lens has an optical power, and the image sides of the second lens and the third lens are convex surfaces; and a spacer element, wherein the spacer element includes a first spacer element, and the first spacer element is located between the first lens and the second lens and abuts against the second side surface of the first lens. The optical system satisfies the following conditions: 0.9 < L / f < 1.4 and 1.4 < d1m / F1 < 2.3, where f is the effective focal length of the optical system, L is the maximum horizontal distance along the optical axis from the object side surface of the lens barrel to the image side surface of the lens barrel, F1 is the focal length of the optical element group, and d1m is the inner diameter of the plane perpendicular to the optical axis of the image side of the spacer element.

2. The optical system of the head-mounted device according to claim 1, wherein the spacer element further includes a second spacer element, and the second spacer element is disposed between the second lens and the third lens. The optical system of the head-mounted device further satisfies the following conditions: 0.30 < EP12 / (d1s - 2*DT11) < 2.55, where EP12 is the axial spacing distance between the image side of the first spacer element and the object side of the second spacer element, d1s is the inner diameter of the plane perpendicular to the optical axis of the object side of the spacer element, and DT11 is the maximum effective radius of the object side of the first lens.

3. The optical system of a head-mounted device according to claim 2, wherein the optical system of a head-mounted device further satisfies the condition: 2.0 < (Dls - dl m) / |SAG11| < 12.6, where, d1m is the inner diameter of the plane perpendicular to the optical axis of the image side of the first spacer element, D1s is the outer diameter of the plane perpendicular to the optical axis of the object side of the first spacer element, and SAG11 is the axial distance between the intersection of the object side of the first lens and the optical axis and the vertex of the effective radius of the object side of the first lens.

4. The optical system of a head-mounted device according to claim 3, wherein the optical system of a head-mounted device further satisfies the condition: 0.80 < EP01 / CT1 < 1.25, where, EP01 is the axial spacing distance from the object side end face of the lens barrel to the object side of the first spacer element, and CT1 is the central thickness of the first lens on the optical axis.

5. The optical system of a head-mounted device according to claim 4, wherein the optical system of a head-mounted device further satisfies the condition: 1.4 < L / EP02< 1.7, where, L is the maximum horizontal distance along the optical axis from the object side end face of the lens barrel to the image side end face of the lens barrel, and EP02 is the axial spacing distance from the object side end face of the lens barrel to the object side of the second spacer element.

6. The optical system of a head-mounted device according to claim 5, wherein the optical system of a head-mounted device further satisfies the condition: 0.15 < CP1 / (CT1+T12) < 0.80, where, CP1 is the maximum thickness of the first spacer element along the optical axis, CT1 is the central thickness of the first lens on the optical axis, and T12 is the air gap between the first lens and the second lens on the optical axis.

7. The optical system of a head-mounted device according to claim 6, wherein the optical system of a head-mounted device further satisfies the condition: 1.4 < CP2 / T23 < 6.2, where, CP2 is the maximum thickness of the second spacer element along the optical axis, and T23 is the air gap between the second lens and the third lens on the optical axis.

8. The optical system of a head-mounted device according to claim 7, wherein the optical system of a head-mounted device further satisfies the condition: 2.05 < do m / DT32 < 3.30, where, d0m is the inner diameter of the plane perpendicular to the optical axis of the image side of the lens barrel, and DT32 is the maximum effective radius of the image side of the third lens.

9. The optical system of a head-mounted device according to claim 8, wherein the optical system of a head-mounted device further satisfies the condition: 35.05 < d2m / |SAG22| < 59.35, where, d2m is the inner diameter of the plane perpendicular to the optical axis of the image side of the second spacer element, and SAG22 is the axial distance between the intersection of the image side of the second lens and the optical axis and the vertex of the effective radius of the image side of the second lens.

10. The optical system of a head-mounted device according to claim 9, wherein the optical system of a head-mounted device further satisfies the condition: 0.20 < (d0m - d0s) / f < 1.30, where, d0s is the inner diameter of the barrel object side surface perpendicular to the plane of the optical axis, d0m is the inner diameter of the barrel image side surface perpendicular to the plane of the optical axis.

11. The optical system of a head-mounted device according to claim 10, wherein the optical system of a head-mounted device further satisfies the condition: 0.95 < dlm / (DT12*2) < 1.20, where, d1m is the inner diameter of the image side surface of the first spacer element perpendicular to the plane of the optical axis, DT12 is the maximum effective radius of the first lens image side surface.

12. The optical system of a head-mounted device according to claim 11, wherein the optical system of a head-mounted device further satisfies the condition: 0.95 < (CP1 + E12 + CP2) / (T12 + CT2 + T23) < 2.80, where, CP1 is the maximum thickness of the first spacer element in the direction of the optical axis, CP2 is the maximum thickness of the second spacer element in the direction of the optical axis, T12 is the air spacing of the first lens and the second lens on the optical axis, T23 is the air spacing of the second lens and the third lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis.

13. The optical system of a head-mounted device according to claim 12, wherein the optical system of a head-mounted device further satisfies the condition: -4.85 < f23 / R5 * (CP2 / T23) < 9.3, where, f23 is the combined focal length of the second lens and the third lens, R5 is the radius of curvature of the third lens object side surface, T23 is the air spacing of the second lens and the third lens on the optical axis.

14. The optical system of a head-mounted device of claim 13, wherein the optical system of a head-mounted device further satisfies the condition: 0.05 < CP2 / |SAG31| < 0.30, where, SAG31 is the on-axis distance between the intersection of the third lens object side surface and the optical axis and the vertex of the effective radius of the third lens object side surface.

15. A headset, characterized in that comprising: a head-mounted device body; and at least one optical system as claimed in any one of claims 1 to 14, wherein the optical system is mounted on the head-mounted device body.

Images