VR eyepiece device

Abstract

The utility model relates to a VR eyepiece device which comprises a lens barrel, a lens group and a spacing element group, the lens group comprises first to fourth lenses and an optical filter which are sequentially mounted on the lens barrel from the eye side to the image side of the lens barrel and share the same optical axis, the image side surface of the third lens and the eye side surface of the fourth lens are oppositely and convexly arranged, the focal power of the first lens is positive, the focal power of the third lens is negative, and the focal power of the fourth lens is negative. The spacing element group comprises a third spacing element located between the third lens and the fourth lens. The curvature radius R6 and the curvature radius R7 of the image side face of the third lens and the curvature radius R7 of the eye side face of the fourth lens meet the condition that R6 / R7lt is larger than or equal to-2.60. The central thickness CP3 of the third spacing element and the axial distance T34 from the image side surface of the third lens to the eye side surface of the fourth lens meet the formula: 20 < = CP3 / T34lt; 31.7, the eye-side inner diameter d3s of the third spacer element, the eye-side outer diameter D3s of the third spacer element, and CP3 satisfy: 0.25 lt; (D3s-d3s) / CP3lt; and 0.6.

Description

Technical Field

[0001] This utility model relates to the field of optical lens technology, and in particular to a VR eyepiece device. Background Technology

[0002] With the rapid development of virtual reality technology, VR headsets, as a core component of virtual reality devices, directly affect the user's immersion and experience. Traditional VR headsets suffer from problems such as narrow field of view, severe distortion, and insufficient comfort. Therefore, it is particularly important to develop a VR headset with high definition, wide field of view, low distortion, and comfortable wear. Utility Model Content

[0003] Given that existing VR eyepiece devices suffer from narrow field of view, severe distortion, and insufficient wearing comfort, it is necessary to provide VR eyepiece devices.

[0004] VR eyepiece device, including:

[0005] The microscope tube has an eye-side end face and an image-side end face;

[0006] A lens assembly includes a first lens, a second lens, a third lens, a fourth lens, and a filter, sequentially mounted in the lens barrel from the eye-side end face to the image-side end face and arranged coaxially. The image-side surface of the third lens is a convex surface protruding towards the fourth lens along the optical axis, and the eye-side surface of the fourth lens is a convex surface protruding towards the third lens along the optical axis.

[0007] A group of spacers includes a third spacer located between the third lens and the fourth lens and abutting against the image side of the third lens;

[0008] The first lens has a spherical eye-side and an image-side, the second lens has a spherical eye-side and an image-side, the third lens has an aspherical eye-side and an image-side, and the fourth lens has an aspherical eye-side and an image-side. The first lens has a positive optical power, and the third lens has a negative optical power. The first lens has a polarizing reflective film and a quarter-wave plate attached to its image-side, and the third lens has a semi-reflective and semi-transparent film attached to its image-side.

[0009] The radius of curvature R6 of the image side of the third lens and the radius of curvature R7 of the eye side of the fourth lens satisfy the following condition: -2.60 ≤ R6 / R7 < -0.5;

[0010] The center thickness CP3 of the third spacer element and the axial distance T34 from the image side of the third lens to the eye side of the fourth lens satisfy the following condition: 20 ≤ CP3 / T34 < 31.7;

[0011] The inner diameter d3s of the third spacer element, the outer diameter D3s of the third spacer element, and the center thickness CP3 of the third spacer element satisfy the following condition: 0.25 < (D3s - d3s) / CP3 < 0.6.

[0012] This configuration, with the first to fourth lenses arranged sequentially along the optical axis, forms a clear optical path. The spherical design of the first and second lenses helps reduce aberrations and improve image sharpness, while the aspherical design of the third and fourth lenses further corrects higher-order aberrations, ensuring high resolution and sharpness. The negative optical power of the third lens helps balance the optical power distribution of the entire system, reducing distortion and chromatic aberration. The polarizing reflective film and quarter-wave plate help eliminate reflected light and glare, improving image contrast and color saturation. The semi-reflective film is used to achieve partial transmission and partial reflection of light, which helps to achieve more complex imaging effects, such as virtual reality (VR) functions or adjusting the light distribution to optimize the field of view. The spacer element group ensures the precise spacing and positional relationship between the lenses. When -2.60≤R6 / R7<-0.5, the radii of curvature of R6 and R7 differ significantly, and the image side of the third lens and the eye side of the fourth lens are both convex, which may complicate the light propagation between these two lens surfaces. Especially when the air gap between them (such as the gap formed by the third spacer element) is small, light may experience unnecessary reflection and scattering when passing through these two lens surfaces. Specifically, a lens typically includes a refractive section for refraction and a mounting section for abutting and assembling with the spacer element and lens barrel. The eye-side and image-side of the lens are usually located in the refractive section of the lens. Based on this, the diameter of the refractive section of different lenses is also different. For the VR eyepiece device involved in this application, the refractive section size of the third lens and the refractive section size of the fourth lens differ significantly, and the third spacer element is usually difficult to cover the third lens due to its size versatility. The mounting points of the third and fourth lenses cause unnecessary reflections and scattering of light as it propagates within the VR eyepiece. Particularly at the fourth lens mounting point, stray light reflected and scattered continues to pass through the refractive section of the third lens. Some of this light forms an image in the picture, manifesting as multiple ghost images and large bright spots, while the rest does not form an image but still reaches the eye, resulting in bright edges on the screen. Since the ratio of the radii of curvature R6 and R7 has a limited range, strict tolerance control is necessary during assembly. Insufficient assembly precision can lead to uneven gaps between lenses, causing stray light. A larger CP3 / T34 ratio (20 ≤ CP3 / T34 < 31.7) may indicate a higher precision required during assembly to ensure proper lens alignment. Insufficient assembly precision can also lead to uneven gaps between lenses, causing stray light. Although T34 represents the on-axis distance, in actual assembly, the air gap between lenses can be affected by various factors (such as temperature, humidity, vibration, etc.), causing changes in the gap. If the CP3 / T34 ratio is too large, the effect of this interval change on light propagation may be more significant, thereby increasing the generation of stray light.Now we control the ratio of (D3s-d3s) / CP3. By adjusting this ratio between 0.25 and 0.6, we can optimize the geometry of the spacer element, thereby reducing light scattering and reflection at the edges of the spacer element and further reducing stray light generation. Specifically, optimizing this ratio helps reduce light scattering on the eye side of the third spacer element (i.e., the side closer to the fourth lens), because an appropriate difference in inner and outer diameters provides better light guidance, directing stray light between the third and fourth lenses to the third spacer element, thus avoiding the mounting portions of the third and fourth lenses. Typically, the spacer element between lenses has a light-absorbing function, thus blocking stray light from entering the image in the human eye.

[0013] In one embodiment, the maximum height L of the lens barrel and the on-axis distance TD from the eye side of the first lens to the image side of the fourth lens satisfy the following condition: 1.1 ≤ L / TD < 1.45.

[0014] This design offers several advantages. First, by controlling the L / TD ratio, the overall structural compactness of the VR eyepiece device can be optimized while maintaining optical performance. A smaller ratio means a more compact lens barrel height relative to the total length of the lens group, which helps reduce the overall size and weight of the VR eyepiece device, improving portability and wearing comfort. Second, an excessively long lens barrel (i.e., a larger L value) increases the risk of lens group wobbling in the vertical direction perpendicular to the optical axis. By controlling the L / TD ratio within the aforementioned range when designing the lens group, this application helps limit such wobbling, thereby improving the stability and durability of the optical lens. Finally, limiting the L / TD ratio range also ensures precise alignment between the individual lenses in the lens group during the manufacturing and assembly of the VR eyepiece device, helping to reduce aberrations and distortions caused by assembly errors, and improving image clarity and quality.

[0015] In one embodiment, the spacer group further includes a first spacer element located between the first lens and the third lens and abutting against the image-side surface of the first lens, wherein the effective focal length f1 of the first lens and the eye-side inner diameter d1s of the first spacer element satisfy: 0.15 <d1s / f1<0.3。

[0016] This configuration, through precise control of the ratio, optimizes light transmission between lens groups, reducing light loss and distortion between them. This contributes to improving the overall image quality, image clarity and sharpness, and color reproduction accuracy of the VR eyepiece device. During lens assembly, a suitable d1s / f1 ratio also helps maintain precise alignment between lens groups, reducing image distortion and aberrations caused by assembly errors, further enhancing the overall performance and stability of the VR eyepiece device.

[0017] In one embodiment, the spacer group further includes a first spacer element located between the first lens and the third lens and abutting against the image side of the first lens, wherein the eye-side inner diameter d1s of the first spacer element, the eye-side outer diameter D1s of the first spacer element, and the effective radius DT12 of the image side of the first lens satisfy the following: 0.05 < (D1s - d1s) / DT12 < 0.22.

[0018] This configuration, by precisely controlling the ratio between the difference between the inner and outer diameters of the first spacer element (D1s−d1s) and the effective radius DT12 of the image-side surface of the first lens, optimizes the size and shape of the spacer element. This helps ensure a tight fit between the spacer element group and the lens group, reducing light leakage and scattering between the lens groups, thereby improving the imaging quality of the optical system. Furthermore, a reasonable ratio range helps maintain precise alignment of the lens groups with the optical axis during assembly. Precise control of the spacer element's size reduces image distortion and aberrations caused by assembly errors, improving the overall performance and stability of the lens. Moreover, by adjusting the size and shape of the spacer element, VR eyepiece devices adapted to different application scenarios can be designed: for example, in scenarios requiring higher resolution or smaller size, these needs can be met by optimizing the design of the spacer element.

[0019] In one embodiment, the spacer group further includes a first spacer element located between the first lens and the third lens and abutting against the image-side surface of the first lens, wherein the center thickness CP3 of the third spacer element and the axial distance EP13 from the image-side surface of the first spacer element to the eye-side surface of the third spacer element satisfy: 1.1 <CP3 / EP13<2.1。

[0020] This configuration offers several advantages. First, the proportional range ensures a reasonable relative size between the third spacer element CP3 and the distance EP13 between the first and third spacers, facilitating the efficient allocation of elements within a limited space and avoiding space waste or assembly difficulties caused by excessive compactness. Second, the reasonable spatial layout and element thickness help reduce light reflection and scattering between elements, thereby reducing light loss and improving light utilization and image quality. Third, this proportional range helps balance the focal length relationships between the spacers, ensuring focal length balance throughout the VR eyepiece device. This contributes to better image quality and fewer aberrations. Finally, the precise spatial layout and proportional range help ensure compatibility between the VR eyepiece device and other optical elements or components, facilitating integration and expansion of the VR eyepiece device. Furthermore, the precise spatial layout and proportional range also simplify the manufacturing process, reduce costs, and facilitate the debugging and optimization of the optical system, thus contributing to mass production and rapid delivery.

[0021] In one embodiment, the spacer element group further includes a fourth spacer element with its two ends respectively abutting against the image-side surface of the fourth lens and the eye-side surface of the filter, wherein the axial distance EP34 between the image-side surface of the third spacer element and the eye-side surface of the fourth spacer element and the center thickness CT4 of the fourth lens satisfy: 0.25 <EP34 / CT4<0.45。

[0022] This configuration offers several advantages. First, precise control of the ratio ensures a reasonable spatial allocation between the third spacer element and the fourth lens, contributing to optimal optical performance and structural stability within a limited space, while avoiding wasted space or assembly difficulties caused by excessive compactness. Second, this ratio range enables a relatively compact optical system design for the VR eyepiece device, reducing its overall size and weight while improving portability and wearing comfort. Third, this ratio range helps balance the focal length relationships between various elements, which in turn improves the overall imaging quality and performance of the VR eyepiece device.

[0023] In one embodiment, the inner diameter d0s of the eye-side end face and the effective focal length f of the VR eyepiece device satisfy: 1.6 <d0s / f<3。

[0024] This configuration, where the ratio of the inner diameter d0s of the eyepiece side of the lens barrel to the effective focal length f determines the field of view of the VR eyepiece device. Firstly, within this ratio range, a relatively large d0s allows users to see a wider virtual scene through the VR eyepiece, enhancing immersion and the realism of the virtual experience. Specifically, a larger d0s helps reduce blind spots, allowing users to perceive their surroundings more comprehensively when viewing virtual scenes, improving comfort and satisfaction and reducing discomfort caused by limited field of view. Secondly, a larger d0s helps accommodate different users' interpupillary distance and interpupillary distance requirements, making the VR eyepiece device more widely applicable to different user groups and improving user comfort and satisfaction. Thirdly, a reasonable d0s to f ratio helps reduce aberrations, including spherical aberration, coma, and astigmatism. Reducing aberrations improves image quality, making virtual scenes clearer and sharper. Finally, within this ratio range, light can be distributed more evenly on the eyepiece side of the lens barrel, reducing light loss and improving light utilization and image quality.

[0025] In one embodiment, the inner diameter d0s of the eye-side end face, the inner diameter d0m of the image-side end face, and the maximum height L of the lens barrel satisfy the following: d0s≠d0m, 0.65<|(d0s-d0m)| / L<1.

[0026] This configuration, by precisely controlling the ratio of the difference between d0s and d0m to the maximum height L of the lens barrel, ensures a rational allocation of internal space. This helps achieve optimal optical performance and structural stability within a limited space, while avoiding wasted space or assembly difficulties caused by excessive compactness. In other words, it enables a more compact optical system design, which not only reduces the overall size and weight of the VR eyepiece device but also improves wearing comfort and portability. Furthermore, by adjusting the difference between d0s and d0m, the spatial layout and component dimensions can be optimized, thus flexibly adapting to different application scenarios and meeting the needs for higher resolution, lower distortion, or smaller size.

[0027] In one embodiment, when the inner diameter d0s of the eye-side end face is greater than the inner diameter d0m of the image-side end face, the VR eyepiece device further includes an auxiliary lens tube, wherein the inner diameter d01s of the eye-side side of the auxiliary lens tube, the inner diameter d0s of the eye-side end face, and the inner diameter d0m of the image-side end face satisfy the following condition: 1.4 ≤ d0s / d01s < 1.65.

[0028] This setup offers several advantages. First, the larger d0s relative to d01s means that the eyepiece side of the primary lens can receive a wider range of light, which helps reduce light loss, improves light utilization, and thus optimizes image quality. Second, a reasonable d0s to d01s ratio helps enhance the structural strength of the entire system, making the VR eyepiece device more durable and able to withstand greater impacts and vibrations. Third, a precise ratio helps maintain accurate alignment between components during assembly, reducing assembly errors and improving the system's stability and precision.

[0029] In one embodiment, the spacer group further includes a fourth spacer element with its two ends respectively abutting against the image side of the fourth lens and the eye side of the filter, wherein the center thickness CP4 of the fourth spacer element and the axial distance BL from the image side of the fourth lens to the image side end face satisfy the following condition: 0.1≤CP4 / BL<0.65.

[0030] This setup, by precisely controlling the ratio of CP4 to BL, further optimizes the optical path design and reduces aberrations (such as spherical aberration, coma, and astigmatism), which helps improve image clarity and sharpness, ensuring image quality. Secondly, a reasonable CP4 to BL ratio helps reduce light reflection and scattering inside the lens barrel, thereby improving light utilization. This helps enhance image brightness and contrast, improving the overall visual effect. In addition, the precise ratio helps maintain accurate alignment between components during assembly, reducing assembly errors, improving system stability and precision, and ensuring consistent image quality. This compact and reasonable spatial layout also helps reduce the pressure on the user from the VR eyepiece device, thereby alleviating discomfort during prolonged wear and improving the user experience.

[0031] In one embodiment, the second lens is cemented to the third lens to form an adhesive layer between the second lens and the third lens;

[0032] The refractive index of the adhesive layer is greater than or equal to 1.45 and less than or equal to 1.55; and / or

[0033] The thickness of the adhesive layer is greater than or equal to 0.095 and less than or equal to 0.256.

[0034] This design offers several advantages. First, cemented lenses reduce the air gap between lenses, minimizing the possibility of light reflection and scattering at the lens surface. Second, the adhesive layer typically has a high refractive index, further optimizing the light refraction path, reducing aberrations and distortion, and improving image clarity and sharpness. Third, the design of cemented lenses facilitates the creation of more complex optical systems, such as achromatic lens groups, to correct chromatic aberrations in different wavelengths of light. Furthermore, by precisely controlling the refractive index and thickness of the adhesive layer, the optical performance of the lens group can be further optimized to meet the high resolution and low distortion requirements of VR eyepiece devices. Additionally, the cemented lens tightly bonds two lenses together into a single structure, improving the stability and durability of the lens group. This helps reduce lens displacement or damage caused by vibration or impact, ensuring long-term stable operation of the VR eyepiece device. Finally, as a single structure, the cemented lens simplifies the assembly process and reduces the risk of assembly errors. This contributes to increased production efficiency, reduced manufacturing costs, and ensures consistent optical performance across all VR eyepiece devices.

[0035] In one embodiment, the thickness of the quarter-wave plate is greater than or equal to 0.105 and less than or equal to 0.115; and / or

[0036] The thickness of the polarizing reflective film is greater than or equal to 0.105 and less than or equal to 0.115; and / or

[0037] The thickness of the semi-reflective and semi-permeable membrane is greater than or equal to 0.095 and less than or equal to 0.105.

[0038] This setup, by precisely controlling the thickness of the quarter-wave plate, polarizing reflective film, and adhesive layer, allows for further optimization of the optical path design, meeting the requirements of VR eyepiece devices for high resolution and low distortion.

[0039] In one embodiment, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, and the effective focal length f3 of the third lens satisfy the following relationship: -0.1 <f1 / (f2+f3)≤0.4。

[0040] This setup offers several advantages. First, by adjusting the f1 / (f2+f3) ratio range, the focal length of the entire system can be flexibly adjusted to adapt to different application scenarios and needs. A reasonable f1 / (f2+f3) ratio range helps balance the focal length relationship between the first lens and the cemented lens group, thereby improving the resolution of the entire VR eyepiece device. Second, the cemented lens design helps reduce aberrations and distortions between lens groups, improving image clarity and sharpness. Specifically, by precisely controlling the refractive index Ng of the adhesive layer, the refraction path of light can be further optimized, reducing aberrations. Third, the cemented lens design can also achieve color correction, reducing chromatic aberration between different wavelengths of light and improving image quality. The color reproduction accuracy is specifically manifested in the following ways: the polarizing reflective film can selectively reflect or absorb light waves in specific directions to improve the polarization efficiency of light; the quarter-wave plate can change the polarization state of light waves to further enhance the polarization effect; by precisely controlling the refractive index NRP of the polarizing reflective film and the refractive index NQWP of the quarter-wave plate, glare and ghosting can be reduced, and the contrast and clarity of the image can be improved; finally, reasonable refractive index selection and optical path design can reduce the loss of light when it propagates between lens groups and improve the utilization rate of light; by precisely controlling the refractive index and thickness of each component and optimizing the ratio range of f1 / (f2+f3), the system can be debugged and optimized more easily.

[0041] In one embodiment, the Abbe number V2 of the second lens and the Abbe number V3 of the third lens satisfy the condition: 1.9 ≤ V2 / V3 < 2.6.

[0042] This setup, firstly, uses a convex lens for the second lens and a concave lens with negative optical power for the third lens. The two lenses have opposite spherical aberrations, and by cementing them together, some of the spherical aberration can be canceled out, resulting in a sharper image. In other words, the cemented lens design helps to more accurately correct spherical aberration to improve image quality. Secondly, the Abbe number (V value) is an indicator of the dispersion capability of lens materials. By selecting lens materials with different Abbe numbers for cementation, chromatic aberration can be corrected, making the image formed by the lens combination more consistent across different wavelengths. Furthermore, within the given V2 / V3 range, the lens combination may have better chromatic aberration correction, and combined with the cemented lens, aberrations and chromatic aberration can be reduced, thereby improving image sharpness. Finally, by optimizing the shape, material, and refractive index of the lens and the adhesive layer, image quality can be further improved. In the fields of photography and videography, this lens combination can be applied to high-end cameras and lenses to improve shooting quality. It reduces aberrations and chromatic aberration, making the photos and videos clearer and more realistic.

[0043] In one embodiment, the spacer group further includes a first spacer located between the first lens and the third lens and abutting against the image side of the first lens, wherein the axial distance EP01 from the eye side end face to the eye side face of the first spacer, the center thickness CP1 of the first spacer, the center thickness CT1 of the first lens, the center thickness CTRP of the polarizing reflective film, and the center thickness CTQWP of the quarter-wave plate satisfy the following: 0.6 < (EP01 + CP1) / (CT1 + CTRP + CTQWP) < 1.8.

[0044] This configuration, firstly, allows for a more compact optical system design by precisely controlling the axial distance EP01 between the eyepiece side of the lens barrel and the eyepiece side of the first spacer element, the center thickness CP1 of the first spacer element, the center thickness CT1 of the first lens, the center thickness CTRP of the polarizing reflective film, and the center thickness CTQWP of the quarter-wave plate. Secondly, this proportional range ensures a relatively reasonable spatial allocation between the various components, avoiding space waste or assembly difficulties caused by excessive compactness, which helps achieve optimal optical performance and structural stability within a limited space. Furthermore, a reasonable spatial layout and component thickness help reduce light reflection, scattering, and absorption between components. Reducing light loss improves light utilization and image quality. Furthermore, by precisely controlling the position and thickness of each component, the optical path design can be further optimized, reducing aberrations and distortions, which helps to achieve clearer and sharper images. The design of cemented lenses and polarizing elements helps to achieve color correction, reducing color differences between different wavelengths of light, which helps to improve the color reproduction and saturation of images. Finally, precise spatial layout and proportion range not only help to maintain accurate alignment between components during assembly, reduce assembly errors, and improve system stability and accuracy, but also help to simplify the manufacturing process, reduce manufacturing costs, and facilitate mass production and rapid delivery.

[0045] In one embodiment, the spacer element group further includes a first spacer element located between the first lens and the third lens and abutting against the image-side surface of the first lens, wherein the axial distance EP13 between the image-side surface of the first spacer element and the eye-side surface of the third spacer element and the axial distance Tr3r6 between the eye-side surface of the second lens and the image-side surface of the third lens satisfy: 0.35 <EP13 / Tr3r6<0.7。

[0046] This setup offers several advantages. First, by precisely controlling the axial distance EP13 between the image-side of the first spacer element and the eye-side of the third spacer element, and the axial distance Tr3r6 between the eye-side of the second lens and the image-side of the third lens, a more compact optical system design can be achieved. This compact design helps reduce the overall size and weight of the VR eyepiece device, improving wearing comfort and portability. Second, this proportional range ensures a relatively reasonable spatial allocation between the various elements, avoiding space waste or assembly difficulties caused by excessive compactness. This helps achieve optimal optical performance and structural stability within a limited space. Furthermore, by precisely controlling the position and distance of each element, the optical path design can be optimized and aberrations and distortions reduced, contributing to clearer and sharper images. Finally, by adjusting the position and distance of each element, it can flexibly adapt to different application scenarios and requirements. For example, in VR eyepiece devices requiring higher resolution, lower distortion, or smaller size, these requirements can be met by optimizing the spatial layout and element distances. Precise spatial layout and proportional range help simplify the manufacturing process, reduce manufacturing costs, and thus enable mass production and rapid delivery. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the structure of the VR eyepiece device in one embodiment of this application;

[0048] Figure 2A This is a schematic diagram of the VR eyepiece device in Example 1 under operating condition 1-1;

[0049] Figure 2B This is a schematic diagram of the VR eyepiece device in Example 1 under operating conditions 1-2;

[0050] Figure 2C This is a schematic diagram of the VR eyepiece device in Example 1 under operating conditions 1-3;

[0051] Figure 3A This is an on-axis chromatic aberration curve of the VR eyepiece device in Example 1;

[0052] Figure 3B This is an astigmatism curve diagram of the VR eyepiece device in Example 1;

[0053] Figure 3C This is a distortion curve diagram of the VR eyepiece device in Example 1;

[0054] Figure 4A This is a schematic diagram of the VR eyepiece device in Example 2 under operating condition 2-1;

[0055] Figure 4B This is a schematic diagram of the VR eyepiece device in Example 2 under operating condition 2-2;

[0056] Figure 4C This is a schematic diagram of the VR eyepiece device in Example 2 under operating conditions 2-3;

[0057] Figure 5A This is an on-axis chromatic aberration curve of the VR eyepiece device in Example 2;

[0058] Figure 5B This is an astigmatism curve diagram of the VR eyepiece device in Example 2;

[0059] Figure 5C This is a distortion curve diagram of the VR eyepiece device in Example 2;

[0060] Figure 6A This is a schematic diagram of the VR eyepiece device in Example 3 under operating condition 3-1;

[0061] Figure 6B This is a schematic diagram of the VR eyepiece device in Example 3 under operating condition 3-2;

[0062] Figure 6C This is a schematic diagram of the VR eyepiece device in Example 3 under operating condition 3-3;

[0063] Figure 7A This is an on-axis chromatic aberration curve of the VR eyepiece device in Example 3;

[0064] Figure 7B This is an astigmatism curve diagram of the VR eyepiece device in Example 3;

[0065] Figure 7C This is a distortion curve diagram of the VR eyepiece device in Example 3;

[0066] Figure 8A This is the MTF curve of the VR eyepiece device in Example 2 under operating condition 2-2;

[0067] Figure 8B The MTF curve of the VR eyepiece device in Example 2 is shown when the parameter (D3s-d3s) / CP3 is 0.1 in modified working condition 2-2.

[0068] Figure 8C This is the MTF curve of the VR eyepiece device in Example 2 when the parameter (D3s-d3s) / CP3 is 1 in modified condition 2-2;

[0069] Figure 9 This is a schematic diagram of the optical paths of effective light and stray light in a VR eyepiece device.

[0070] Figure label:

[0071] P0, lens barrel; P01, first auxiliary spacer element; P1, first spacer element; P3, third spacer element; P3b, third auxiliary spacer element; P4, fourth spacer element; L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, filter. Detailed Implementation

[0072] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0073] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0074] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0075] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0076] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0077] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0078] With the rapid development of virtual reality technology, VR headsets, as a core component of virtual reality devices, directly affect the user's immersion and experience. Traditional VR headsets suffer from problems such as narrow field of view, severe distortion, and insufficient comfort. Therefore, it is particularly important to develop a VR headset with high definition, wide field of view, low distortion, and comfortable wear.

[0079] The unit of length in this application is millimeters (mm).

[0080] Please see Figure 1 , Figures 8A to 8C and Figure 9 , Figure 1 This is a schematic diagram of the VR eyepiece device in one embodiment of this application. Figure 8A This is the MTF curve of the VR eyepiece device in Example 2 under operating condition 2-2. Figure 8B This is the MTF curve of the VR eyepiece device in Example 2 when the parameter (D3s-d3s) / CP3 is 0.1 in modified operating condition 2-2. Figure 8C This is the MTF curve of the VR eyepiece device in Example 2 when the parameter (D3s-d3s) / CP3 is 1 in modified condition 2-2. Figure 9This is a schematic diagram of the optical paths of effective light and stray light in a VR eyepiece device. The VR eyepiece device provided in this application includes a lens barrel P0 with an eye-side end face and an image-side end face, a lens group, and a spacer element group. The lens group includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a filter L5, which are sequentially mounted on the lens barrel P0 from the eye-side end face to the image-side end face and arranged coaxially to form a clear optical path. The inner ring surface of the lens barrel P0 is stepped to accommodate the dimensions of the first to fourth lenses L4. The image-side surface of the third lens L3 is a convex surface protruding towards the fourth lens L4 along the optical axis, and the eye-side surface of the fourth lens L4 is a convex surface protruding towards the third lens L3 along the optical axis. The spacer element group includes a first spacer element P1 located between the first lens L1 and the third lens L3 and abutting against the image-side surface of the first lens L1, and a third spacer element located between the third lens L3 and the fourth lens L4 and abutting against the image-side surface of the third lens L3. P3 and the fourth spacer element P4, whose two ends respectively abut against the image side of the fourth lens L4 and the eye side of the filter L5; the eye side and image side of the first lens L1 are spherical, the eye side and image side of the second lens L2 are spherical, which helps to reduce aberrations; the eye side and image side of the third lens L3 are aspherical, and the eye side and image side of the fourth lens L4 are aspherical, which helps to further correct higher-order aberrations and ensure high resolution and sharpness of the image; the optical power of the first lens L1 is positive, and the optical power of the third lens L3 is negative; the image side of the first lens L1 is covered with a polarizing reflective film and a quarter-wave plate to eliminate reflected light and glare, and the image side of the third lens L3 is covered with a semi-reflective and semi-transparent film to achieve more complex imaging effects, such as virtual reality (VR) functions or adjusting light distribution to optimize the field of view. The radius of curvature R6 of the image-side surface of the third lens L3 and the radius of curvature R7 of the eye-side surface of the fourth lens L4 satisfy the condition: -2.60 ≤ R6 / R7 < -0.5, preferably -2.60 ≤ R6 / R7 < -1.65; the center thickness CP3 of the third spacer P3 and the axial distance T34 from the image-side surface of the third lens L3 to the eye-side surface of the fourth lens L4 satisfy the condition: 20 ≤ CP3 / T34 < 31.7. However, under these conditions, the propagation of light between these two lens surfaces may become complicated.Especially when the air gap between them (such as the gap formed by the third spacer element P3) is small, light may produce unnecessary reflection and scattering when passing through these two lens surfaces. Specifically, a lens typically includes a refractive section for refraction and a mounting section for abutting and assembling with the spacer element and lens barrel. The eyepiece side and image side of the lens are usually located in the refractive section of the lens. Based on this, the diameter of the refractive section of different lenses is also different. For the VR eyepiece device involved in this application, the refractive section size of the third lens L3 and the refractive section size of the fourth lens L4 differ significantly, and the third spacer element P3 is usually difficult to cover the third lens due to its size versatility. The mounting points of the third lens L3 and the fourth lens L4 cause unnecessary reflections and scattering of light as it propagates within the VR eyepiece device. Particularly, stray light reflected and scattered from the mounting point of the fourth lens L4 continues to pass through the refractive section of the third lens L3. Some of this light forms an image in the picture, resulting in multiple ghost images and large bright spots; the other part does not form an image but still reaches the eye, resulting in bright edges on the screen. Since the ratio of the radii of curvature of R6 and R7 has a limited range, strict tolerance control is required during assembly. Insufficient assembly precision may lead to uneven gaps between lenses, causing stray light. A larger CP3 / T34 ratio may mean higher precision is needed during assembly to ensure proper alignment between lenses. Although T34 represents the on-axis distance, in actual assembly, the air gap between lenses may be affected by various factors (such as temperature, humidity, vibration, etc.), causing changes in the gap. If the CP3 / T34 ratio is too large, the effect of this spacing change on light propagation may be more significant, thereby increasing the generation of stray light. Therefore, in the VR eyepiece device provided in this application, the eye-side inner diameter d3s, the eye-side outer diameter D3s of the third spacer element P3, and the center thickness CP3 of the third spacer element P3 are also made to satisfy: 0.25 < (D3s - d3s) / CP3 < 0.6.By setting (D3s - d3s) / CP3 within the above range, the geometry of the third spacer element P3 can be optimized, thereby reducing the scattering and reflection of light at the edges of the spacer element, and further reducing the generation of stray light. Within this ratio range, the third spacer element P3 can provide better guidance for light, guiding the stray light between the third lens L3 and the fourth lens L4 to the third spacer element P3, thereby avoiding the mounting parts of the two lenses, the third lens L3 and the fourth lens L4. Usually, the spacer element between lenses has the function of absorbing light, thereby reducing unnecessary reflection and scattering at the third spacer element P3 (especially on the side of the third spacer element P3 close to the fourth lens L4), blocking the stray light from entering the human eye image to improve the image quality. Exemplarily, as. Figures 8A to 8C As shown, when the ratio of the curvature radii of R6 and R7 is 2.6 and CP3 / T34 is 21.37, and the value of (D3s - d3s) / CP3 is 0.43, the MTF index of this VR eyepiece device is good and the resolution is high.

[0081] Optionally, in order to increase the structural compactness of the VR eyepiece device, so as to achieve the purpose of reducing the volume and weight of the entire VR eyepiece device and improving portability and wearing comfort, in the VR eyepiece device provided in this application, the maximum height L of the lens barrel P0 and the axial distance TD from the object side surface of the first lens L1 to the image side surface of the fourth lens L4 satisfy: 1.1 ≤ L / TD < 1.45. In addition, controlling the ratio of L / TD within the above range helps to limit the risk of the lens group shaking in the vertical direction of the optical axis, thereby improving the stability and durability of the optical lens. The ratio range limit of L / TD can also keep the lenses of the lens group precisely aligned during the manufacturing and assembly process of the VR eyepiece device, helping to reduce the aberration and distortion caused by assembly errors and improving the clarity and quality of the image.

[0082] Optionally, in order to reduce the loss and distortion of light during propagation between the lens groups, and further improve the imaging quality, image clarity, sharpness and color reproduction accuracy of the entire VR eyepiece device, in an embodiment provided in this application, the effective focal length f1 of the first lens L1 and the inner diameter d1s of the object side of the first spacer element P1 satisfy: 0.15 < d1s / f1 < 0.3, preferably satisfy: 0.15 < d1s / f1 < 0.28. In addition, during the lens assembly process, a reasonable d1s / f1 ratio also helps to maintain the precise alignment between the lens groups, thereby reducing image distortion and aberration caused by assembly errors, and further improving the overall performance and stability of the VR eyepiece device.

[0083] Optionally, to ensure a tight fit between the spacer element group and the lens group, reduce light leakage and scattering between the lens groups, and thus improve the imaging quality of the optical system, in an embodiment provided in the present application, the following relationship is satisfied among the object-side inner diameter d1s of the first spacer element P1, the object-side outer diameter D1s of the first spacer element P1, and the effective radius DT12 of the image side surface of the first lens L1: 0.05 < (D1s - d1s) / DT12 < 0.22. In addition, a reasonable ratio range helps to maintain the precise alignment of the lens groups along the optical axis during the assembly process. By precisely controlling the dimensions of the spacer elements, image distortion and aberrations caused by assembly errors can be reduced, improving the overall performance and stability of the lens; further, by adjusting the dimensions and shapes of the spacer elements, VR eyepiece devices adapted to different application scenarios can be designed: for example, in scenarios requiring higher resolution or smaller volume, these requirements can be met by optimizing the design of the spacer elements.

[0084] Optionally, to reasonably allocate the positions of each element for convenient assembly and reduce light loss, in an embodiment provided in the present application, the following relationship is satisfied between the central thickness CP3 of the third spacer element P3 and the on-axis distance EP13 from the image side surface of the first spacer element P1 to the object side surface of the third spacer element P3: 1.1 < CP3 / EP13 < 2.1. In addition, this ratio range also helps to ensure the focal length balance of the entire VR eyepiece device, thereby obtaining better imaging quality and smaller aberrations. From the perspective of the application scenarios of mass production and the requirements of rapid delivery, such a precise spatial layout and ratio range also help to simplify the manufacturing process, reduce costs, and facilitate the debugging and optimization of the optical system, achieving the purpose of shortening the production cycle.

[0085] Optionally, to achieve the best optical performance and structural stability within a limited space, while avoiding assembly difficulties caused by space waste or excessive compactness, in an embodiment of the present application, the following relationship is satisfied between the on-axis distance EP34 from the image side surface of the third spacer element P3 to the object side surface of the fourth spacer element P4 and the central thickness CT4 of the fourth lens L4: 0.25 < EP34 / CT4 < 0.45. In addition, this ratio range also helps to balance the focal length relationship between each element, and focal length balance helps to improve the imaging quality and performance of the entire VR eyepiece device.

[0086] Optionally, to enhance the user's immersion and realism, in an embodiment provided by the present application, the inner diameter d0s of the ocular side end face and the effective focal length f of the VR eyepiece device satisfy: 1.6 < d0s / f < 3. This can reduce the visual field blind area and adapt to the eye distance and pupil distance requirements of different users. A reasonable ratio relationship between d0s and f helps reduce aberrations, including spherical aberration, coma, astigmatism, etc., and the light can be more evenly distributed on the ocular side face of the lens barrel P0, which helps reduce light loss, improve the light utilization rate and imaging quality.

[0087] Optionally, to make the internal structure of the VR eyepiece device more compact, in an embodiment provided by the present application, the inner diameter d0s of the ocular side end face, the inner diameter d0m of the image side end face, and the maximum height L of the lens barrel P0 satisfy: d0s ≠ d0m, 0.65 < |(d0s - d0m)| / L < 1. By adjusting the difference between d0s and d0m, the spatial layout and component sizes can also be optimized, so as to flexibly adapt to different application scenarios and meet the requirements of higher resolution, lower distortion or smaller volume.

[0088] Optionally, to improve the light utilization rate and increase the structural strength of the entire VR eyepiece device, in an embodiment provided by the present application, when the inner diameter d0s of the ocular side end face is greater than the inner diameter d0m of the image side end face, the VR eyepiece device further includes an auxiliary lens barrel P0. The inner diameter d01s of the ocular side face of the auxiliary lens barrel P0, the inner diameter d0s of the ocular side end face, and the inner diameter d0m of the image side end face satisfy: 1.4 ≤ d0s / d01s < 1.65.

[0089] Optionally, to improve the clarity and sharpness of the image and ensure the imaging quality, in an embodiment provided by the present application, the central thickness CP4 of the fourth spacer element P4 and the axial distance BL from the image side face of the fourth lens L4 to the image side end face satisfy: 0.1 ≤ CP4 / BL < 0.65.

[0090] Optionally, to meet the requirements of the VR eyepiece device for high resolution and low distortion, the polarization reflective film, the quarter-wave plate, and the semi-transmissive semi-reflective film respectively have certain thicknesses. The thickness range of the quarter-wave plate is greater than or equal to 0.105 and less than or equal to 0.115, the thickness range of the polarization reflective film is greater than or equal to 0.105 and less than or equal to 0.115, and the thickness range of the semi-transmissive semi-reflective film is greater than or equal to 0.195 and less than or equal to 0.205. Specifically, in the embodiment provided by the present application, the thicknesses of the polarization reflective film and the quarter-wave plate are both 0.11.

[0091] Optionally, in an embodiment provided by the present application, the second lens L2 and the third lens L3 are glued together to form a glue layer with a certain thickness and a certain refractive index between the second lens L2 and the third lens L3. The refractive index range of the glue layer is greater than or equal to 1.45 and less than or equal to 1.55, and the thickness range of the glue layer is greater than or equal to 0.095 and less than or equal to 0.256. Specifically, in the embodiment provided by the present application, the refractive index of the glue layer is 1.5. Such a setting has at least the following advantages: First, the glued lens can reduce the air gap between the lenses, thereby reducing the possibility of light reflection and scattering on the lens surface; Second, the glue layer usually has a high refractive index, which can further optimize the refraction path of light, reduce aberration and distortion, and improve the clarity and sharpness of the image; Third, the design of the glued lens helps to realize a more complex optical system, such as an achromatic lens group, to correct the chromatic aberration of light with different wavelengths; Further, by precisely controlling the refractive index and thickness of the glue layer, the optical performance of the lens group can be further optimized to meet the requirements of the VR eyepiece device for high resolution, low distortion, etc.; In addition, the glued lens tightly combines the two lenses together to form an integral structure, which helps to improve the stability and durability of the lens group, which helps to reduce the lens displacement or damage caused by vibration or impact, and ensure the long-term stable operation of the VR eyepiece device; Finally, the glued lens as an integral structure simplifies the assembly process and reduces the risk of assembly errors. This helps to improve production efficiency, reduce manufacturing costs, and ensure the optical performance consistency of each VR eyepiece device. It can be understood that in other embodiments, if only to fix the second lens L2, a second spacer element may also be provided between the second lens L2 and the third lens L3, and both ends of the second spacer element are respectively abutted against the image side of the second lens L2 and the ocular side of the third lens L3.

[0092] Optionally, in order to better balance the overall focal length of the VR eyepiece device to improve the resolution of the entire VR eyepiece device, in an embodiment provided by the present application, the effective focal length f1 of the first lens L1, the effective focal length f2 of the second lens L2, and the effective focal length f3 of the third lens L3 satisfy: -0.1 < f_{1} / (f_{2}+f_{3}) ≤ 0.4.配合胶合透镜及膜层对于光线的折射作用,能够减少炫光和鬼影的产生,有利于提高图像的对比度和清晰度,除此之外,合理的折射率选择和光路设计可以减少光线在透镜组之间传播时的损失,提高光线e utilization rate, and by precisely controlling the refractive index and thickness of each element, as well as optimizing the ratio range of f_{1} / (f_{2}+f_{3}), it is also easier to achieve system debugging and optimization.Paired with the refraction of light by the glued lens and the film layer, it is possible to reduce the generation of glare and ghost images, which is beneficial to improving the contrast and clarity of the image. In addition, reasonable refractive index selection and optical path design can reduce the loss of light when propagating between lens groups, improve the light utilization rate, and by precisely controlling the refractive index and thickness of each element, as well as optimizing the ratio range of f_{1} / (f_{2}+f_{3}), it is also easier to achieve system debugging and optimization.

[0093] Optionally, to correct chromatic aberration, in one embodiment provided in this application, the Abbe number V2 of the second lens L2 and the Abbe number V3 of the third lens L3 satisfy: 1.9 ≤ V2 / V3 < 2.6, preferably satisfying: 2.1 ≤ V2 / V3 < 2.6. Furthermore, by combining the cemented lens and the spherical aberration cancellation compensation between the second lens L2 and the third lens L3, the imaging clarity of the VR eyepiece device can be improved.

[0094] Optionally, in order to achieve optimal optical performance and structural stability within a limited space, in one embodiment provided in this application, the axial distance EP01 from the eye-side end face to the eye-side surface of the first spacer element P1, the center thickness CP1 of the first spacer element P1, the center thickness CT1 of the first lens L1, the center thickness CTRP of the polarizing reflective film, and the center thickness CTQWP of the quarter-wave plate satisfy the following: 0.6 < (EP01 + CP1) / (CT1 + CTRP + CTQWP) < 1.8.

[0095] Optionally, in order to achieve the most compact structure of the VR eyepiece device while realizing assembly, in one embodiment provided in this application, the axial distance EP13 between the image side of the first spacer element P1 and the eye side of the third spacer element P3, and the axial distance Tr3r6 between the eye side of the second lens L2 and the image side of the third lens L3, satisfy: 0.35 <EP13 / Tr3r6<0.7。

[0096] The following describes some specific, non-limiting examples of embodiments of this application in more detail with reference to the accompanying drawings. It is understood that any of the examples one through three described below is applicable to all embodiments of this application.

[0097] For ease of description, in the following examples, STO represents the surface of the aperture stop, IMG represents the image plane of the VR eyepiece device, f represents the effective focal length of the VR eyepiece device; fi represents the effective focal length of the i-th lens, i=1, 2, 3, 4, HFOV represents the horizontal field of view, FNO is the ratio of the focal length of the VR eyepiece device to the entrance pupil diameter, reflecting the light transmission capability of the VR eyepiece device, REFL1 represents the first lens L1, RELF2 represents the second lens L2, and RELF3 represents the third lens L3.

[0098] Furthermore, the surface numbers of the functional surfaces along the reverse direction of the light path are sequentially defined as S1 to SN, where S1 represents the surface number of the first functional surface along the reverse direction of the light path, and SN represents the surface number of the Nth functional surface along the reverse direction of the light path.

[0099] Please see Figure 2A , Figure 4A and Figure 6AThe three figures illustrate the structural schematic diagrams of the VR eyepiece device in three embodiments provided in this application. Specifically, S1 represents the eye-side surface of the first lens L1, S2 represents the bonding surface between the first lens L1 and the polarizing reflective film, S3 represents the bonding surface between the polarizing reflective film and the quarter-wave plate, S4 represents the image-side surface of the quarter-wave plate, S5 represents the eye-side surface of the second lens L2, S6 represents the bonding surface between the second lens L2 and the adhesive layer, S7 represents the bonding surface between the adhesive layer and the third lens L3, S8 represents the bonding surface between the third lens L3 and the semi-reflective film, S9 represents the eye-side surface of the fourth lens L4, S10 represents the image-side surface of the fourth lens L4, S11 represents the eye-side surface of the filter L5, and S12 represents the image-side surface of the filter L5.

[0100] The light path and surface numbers are explained as follows: The light path is refracted on eleven surfaces, S1, S2, S4~S7 and S9~S13, while it is reflected on two surfaces, S3 and S8. Specifically, the light enters the VR eyepiece device from S12, passes through S11~S4 in sequence and arrives at the polarizing reflective film located at S3. After being reflected by S3, it passes through S4~S6 in sequence and arrives at the semi-reflective and semi-transparent film located at S8. After being reflected by S8, it passes through S7~S1 in sequence and arrives at the pupil.

[0101] The quadric surfaces and aspherical surfaces involved in this patent still satisfy the following formula:

[0102]

[0103] In the above formula, x represents the surface droop parallel to the optical axis, c represents the curvature, h represents the radial distance from the optical axis, k represents the quadratic surface constant, and Ai represents the i-th order constant.

[0104] Example 1

[0105] like Figures 2A-2C As shown, Figures 2A-2C These are schematic diagrams of the VR eyepiece device under three different operating conditions provided in Embodiment 1. Specifically, in... Figure 2A and Figure 2B In the corresponding operating conditions 1-1 and 1-2, the eye-side end face of the lens barrel P0 is provided with a stop step, which abuts against the eye-side surface of the first lens L1 to axially limit the first lens L1 together with the first spacer element P1. And... Figure 2C In the corresponding operating conditions 1-3, the VR eyepiece device also includes a first auxiliary spacer element P01 located on the eye side end face of the lens barrel P0 and installed on the inner ring surface of the lens barrel P0. The first auxiliary spacer element P01 abuts against the eye side face of the first lens L1 to limit the first lens L1 axially together with the first spacer element P1.

[0106] Table 1 provides the design data for the VR eyepiece device in Example 1, and Table 2 provides the higher-order coefficient parameters of the four surfaces S7 to S10.

[0107] Table 1

[0108]

[0109] Table 2

[0110]

[0111] After simulation testing, the results are as follows: Figures 3A-3C As shown, Figures 3A-3C These are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve for the VR eyepiece device. According to... Figures 3A to 3C It can be seen that the VR eyepiece device in Embodiment 1 can achieve good imaging quality.

[0112] Example 2

[0113] like Figures 4A-4C As shown, Figures 4A-4C These are schematic diagrams of the VR eyepiece device under three different operating conditions provided in Embodiment 2. Specifically, in Figure 4A and 4B In operating conditions 2-1 and 2-2 respectively, the eyepiece side end face of the lens barrel P0 is provided with a stop step, which abuts against the eyepiece side face of the first lens L1 to axially limit the first lens L1 together with the first spacer element P1. Figure 4C In the corresponding operating conditions 2-3, the VR eyepiece device also includes a first auxiliary spacer element P01 located on the eye-side end face of the lens barrel P0 and sleeved on the outer annular surface of the lens barrel P0. This first auxiliary spacer element P01 is arranged spaced apart from the first lens L1. Figure 4A In the corresponding operating condition 2-1, the VR eyepiece device also includes a third auxiliary spacer element P3b, with its two ends respectively abutting the image-side surface of the third spacer unit and the eye-side surface of the fourth lens L4; furthermore, the two ends of the first spacer element P1 abut the image-side surface and the eye-side surface of the first lens L1, respectively. Figure 4B and Figure 4C In the corresponding working conditions 2-2 and 2-3, the two ends of the first spacing unit abut against the image side of the first lens L1 and the eye side of the third lens L3, respectively, and the second lens L2 is arranged at an interval from the first lens L1.

[0114] Table 3 shows the design data of the VR eyepiece device in Example 2, and Table 4 shows the higher-order coefficient parameters of the four surfaces S7 to S10.

[0115] Table 3

[0116]

[0117] Table 4

[0118]

[0119] After simulation testing, the results are as follows: Figures 5A-5C As shown, Figures 5A-5C These are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve for the VR eyepiece device. According to... Figures 5A to 5C It can be seen that the VR eyepiece device in Embodiment 2 can achieve good imaging quality.

[0120] Example 3

[0121] like Figures 6A-6C As shown, Figures 6A-6C These are schematic diagrams of the VR eyepiece device under three different operating conditions provided in Embodiment 3. Specifically, in Figure 6A and 6B In operating conditions 3-1 and 3-2 respectively, the eyepiece side end face of the lens barrel P0 is provided with a stop step, which abuts against the eyepiece side face of the first lens L1 to axially limit the first lens L1 together with the first spacer element P1. Figure 6C In the corresponding operating condition 3-3, the VR eyepiece device also includes a first auxiliary spacer element P01 located on the eye-side end face of the lens barrel P0 and sleeved on the outer annular surface of the lens barrel P0. This first auxiliary spacer element P01 is spaced apart from the first lens L1. In all three operating conditions, the VR eyepiece device also includes a third auxiliary spacer element P3b, with its two ends respectively abutting against the image-side surface of the third spacer unit and the eye-side surface of the fourth lens L4. Figure 6A In the corresponding operating condition 3-1, the two ends of the first spacer element P1 abut against the image-side surface of the first lens L1 and the eye-side surface of the second lens L2, respectively. Figure 6B and Figure 6C In the corresponding working conditions 3-2 and 3-3, the two ends of the first spacer element P1 are respectively abutted against the image side of the first lens L1 and the eye side of the third lens L3, and the second lens L2 is arranged at an interval from the first lens L1.

[0122] Table 5 shows the design data of the VR eyepiece device in Example 3, and Table 4 shows the higher-order coefficient parameters of the four surfaces S7 to S10.

[0123] Table 5

[0124]

[0125] Table 6

[0126]

[0127] After simulation testing, the results are as follows: Figures 7A-7C As shown, Figures 7A-7CThese are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve for the VR eyepiece device. According to... Figures 7A to 7C It can be seen that the VR eyepiece device in Embodiment 3 can achieve good imaging quality.

[0128] The optical parameters of the three embodiments above are shown in Table 7.

[0129] Table 7

[0130]

[0131] Please see Figure 1 The parameters involved in the VR eyepiece device under various operating conditions are shown in Table 8.

[0132] Table 8

[0133]

[0134] The conditional expressions for the VR eyepiece device under various operating conditions are shown in Table 9.

[0135] Table 9

[0136]

[0137] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0138] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A VR eyepiece device, characterized in that, include: The microscope tube has an eye-side end face and an image-side end face; A lens assembly includes a first lens, a second lens, a third lens, a fourth lens, and a filter, sequentially mounted in the lens barrel from the eye-side end face to the image-side end face and arranged coaxially. The image-side surface of the third lens is a convex surface protruding towards the fourth lens along the optical axis, and the eye-side surface of the fourth lens is a convex surface protruding towards the third lens along the optical axis. A group of spacers includes a third spacer located between the third lens and the fourth lens and abutting against the image side of the third lens; The first lens has a spherical eye-side and an image-side, the second lens has a spherical eye-side and an image-side, the third lens has an aspherical eye-side and an image-side, and the fourth lens has an aspherical eye-side and an image-side. The first lens has a positive optical power, and the third lens has a negative optical power. The first lens has a polarizing reflective film and a quarter-wave plate attached to its image-side, and the third lens has a semi-reflective and semi-transparent film attached to its image-side. The radius of curvature R6 of the image side of the third lens and the radius of curvature R7 of the eye side of the fourth lens satisfy the following condition: -2.60 ≤ R6 / R7 < -0.5; The center thickness CP3 of the third spacer element and the axial distance T34 from the image side of the third lens to the eye side of the fourth lens satisfy the following condition: 20 ≤ CP3 / T34 < 31.7; The inner diameter d3s of the third spacer element, the outer diameter D3s of the third spacer element, and the center thickness CP3 of the third spacer element satisfy the following condition: 0.25 < (D3s - d3s) / CP3 < 0.

6.

2. The VR eyepiece device according to claim 1, characterized in that, The maximum height L of the lens barrel and the on-axis distance TD from the eye side of the first lens to the image side of the fourth lens satisfy the following condition: 1.1 ≤ L / TD < 1.

45.

3. The eyepiece device according to claim 1, characterized in that, The spacer element group further includes a first spacer element located between the first lens and the third lens and abutting against the image-side surface of the first lens, wherein the effective focal length f1 of the first lens and the eye-side inner diameter d1s of the first spacer element satisfy the following condition: 0.15 <d1s / f1<0.3。 4. The VR eyepiece device according to claim 1, characterized in that, The spacer element group further includes a first spacer element located between the first lens and the third lens and abutting against the image side of the first lens. The eye-side inner diameter d1s of the first spacer element, the eye-side outer diameter D1s of the first spacer element, and the effective radius DT12 of the image side of the first lens satisfy the following condition: 0.05 < (D1s - d1s) / DT12 < 0.

22.

5. The VR eyepiece device according to claim 1, characterized in that, The spacer element group further includes a first spacer element located between the first lens and the third lens and abutting against the image-side surface of the first lens. The center thickness CP3 of the third spacer element and the axial distance EP13 from the image-side surface of the first spacer element to the eye-side surface of the third spacer element satisfy: 1.1 <CP3 / EP13<2.1。 6. The VR eyepiece device according to claim 1, characterized in that, The spacer element group further includes a fourth spacer element whose two ends respectively abut against the image-side surface of the fourth lens and the eye-side surface of the filter. The axial distance EP34 between the image-side surface of the third spacer element and the eye-side surface of the fourth spacer element and the center thickness CT4 of the fourth lens satisfy the following condition: 0.

25. <EP34 / CT4<0.45。 7. The VR eyepiece device according to claim 1, characterized in that, The inner diameter d0s of the eyepiece end face and the effective focal length f of the eyepiece device satisfy the following relationship: 1.6 <d0s / f<3。 8. The VR eyepiece device according to claim 1, characterized in that, The inner diameter d0s of the eye-side end face, the inner diameter d0m of the image-side end face, and the maximum height L of the lens tube satisfy the following: d0s≠d0m, 0.65<|(d0s-d0m)| / L<1.

9. The VR eyepiece device according to claim 1, characterized in that, When the inner diameter d0s of the eye-side end face is greater than the inner diameter d0m of the image-side end face, the eyepiece device further includes an auxiliary lens tube, and the inner diameter d01s of the eye-side side of the auxiliary lens tube, the inner diameter d0s of the eye-side end face, and the inner diameter d0m of the image-side end face satisfy the following condition: 1.4≤d0s / d01s<1.

65.

10. The VR eyepiece device according to claim 1, characterized in that, The spacer element group further includes a fourth spacer element whose two ends abut against the image side of the fourth lens and the eye side of the filter, respectively. The center thickness CP4 of the fourth spacer element and the axial distance BL from the image side of the fourth lens to the image side end face satisfy the following condition: 0.1≤CP4 / BL<0.

65.

11. The VR eyepiece device according to any one of claims 1 to 10, characterized in that, The second lens is cemented to the third lens to form an adhesive layer between the second lens and the third lens; The refractive index of the adhesive layer is greater than or equal to 1.45 and less than or equal to 1.55; and / or The thickness of the adhesive layer is greater than or equal to 0.095 and less than or equal to 0.

256.

12. The VR eyepiece device according to claim 11, characterized in that, The thickness of the quarter-wave plate is greater than or equal to 0.105 and less than or equal to 0.115; and / or The thickness of the polarizing reflective film is greater than or equal to 0.105 and less than or equal to 0.115; and / or The thickness of the semi-reflective and semi-permeable membrane is greater than or equal to 0.095 and less than or equal to 0.

105.

13. The VR eyepiece device according to claim 11, characterized in that, The effective focal length f1 of the first lens, the effective focal length f2 of the second lens, and the effective focal length f3 of the third lens satisfy the following relationship: -0.1 <f1 / (f2+f3)≤0.4。 14. The VR eyepiece device according to claim 11, characterized in that, The Abbe number V2 of the second lens and the Abbe number V3 of the third lens satisfy the following condition: 1.9 ≤ V2 / V3 < 2.

6.

15. The VR eyepiece device according to claim 14, characterized in that, The spacer element group further includes a first spacer element located between the first lens and the third lens and abutting against the image side of the first lens. The axial distance EP01 from the eye side end face to the eye side face of the first spacer element, the center thickness CP1 of the first spacer element, the center thickness CT1 of the first lens, the center thickness CTRP of the polarizing reflective film, and the center thickness CTQWP of the quarter-wave plate satisfy the following: 0.6 < (EP01 + CP1) / (CT1 + CTRP + CTQWP) < 1.

8.

16. The VR eyepiece device according to claim 11, characterized in that, The spacer element group further includes a first spacer element located between the first lens and the third lens and abutting against the image-side surface of the first lens. The axial distance EP13 between the image-side surface of the first spacer element and the eye-side surface of the third spacer element and the axial distance Tr3r6 between the eye-side surface of the second lens and the image-side surface of the third lens satisfy: 0.35 <EP13 / Tr3r6<0.7。

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