VR eyepiece device

Abstract

The invention 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] The present invention relates to the field of optical lens technology, and in particular to a VR eyepiece device. Background Art

[0002] With the rapid development of virtual reality technology, VR eyepiece devices, as the core components of virtual reality equipment, have a direct impact on the user's immersion and experience. Traditional VR eyepiece devices have problems such as narrow field of view, severe distortion, and insufficient comfort. Therefore, it is particularly important to develop a VR eyepiece device with high definition, wide viewing angle, low distortion, and comfortable wearing. Summary of the invention

[0003] Since existing VR eyepiece devices have problems such as narrow field of view, severe distortion and insufficient wearing comfort, it is necessary to provide a VR eyepiece device.

[0004] VR eyepiece device, comprising:

[0005] A lens barrel having an eye-side end surface and an image-side end surface;

[0006] a lens group, comprising a first lens, a second lens, a third lens, a fourth lens and a filter which are sequentially installed in the lens barrel from the eye side end surface to the image side end surface and arranged on the same optical axis, wherein the image side surface of the third lens is a convex surface convexly arranged along the optical axis toward the fourth lens, and the eye side surface of the fourth lens is a convex surface convexly arranged along the optical axis toward the third lens; and

[0007] a spacer element group, comprising a third spacer element located between the third lens and the fourth lens and abutting against the image side surface of the third lens;

[0008] The eye side surface and the image side surface of the first lens are spherical surfaces, the eye side surface and the image side surface of the second lens are spherical surfaces, the eye side surface and the image side surface of the third lens are aspherical surfaces, and the eye side surface and the image side surface of the fourth lens are aspherical surfaces; the optical power of the third lens is negative; the image side surface of the first lens is attached with a polarizing reflection film and a quarter wave plate, and the image side surface of the third lens is attached with a semi-reflective and semi-transparent film;

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

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

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

[0012] In this way, the first lens to the fourth lens are arranged in sequence along the optical axis to form a clear optical path. The spherical design of the first lens and the second lens helps to reduce aberrations and improve the clarity of the image, and the aspherical design of the third lens and the fourth lens further corrects high-order aberrations to ensure high resolution and sharpness of the image; the negative focal length of the third lens helps to balance the focal length distribution of the entire system and reduce distortion and chromatic aberration; the setting of the polarizing reflective film and the quarter-wave plate helps to eliminate reflected light and glare, improve the contrast and color saturation of the image, and the semi-reflective and semi-transparent 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 adjust the light distribution to optimize the field of view; the spacer element group ensures the precise spacing and position relationship between the lenses. When -2.60≤R6 / R7<-0.5, the curvature radii of R6 and R7 differ greatly, and the image side of the third lens and the eye side of the fourth lens have the same convex shape, then the light propagation between the two lens surfaces may become complicated. In particular, when the air gap between them (such as the gap formed by the third spacing element) is small, unnecessary reflection and scattering may occur when the light passes through the two lens surfaces. Specifically, the lens usually includes a refractive portion for refraction and a mounting portion for abutting and assembling with the spacing element and the lens barrel. The eye side and the image side of the lens are usually located in the refractive portion of the lens. Based on this, the diameters of the refractive portions of different lenses are also different. For the VR eyepiece device involved in the present application, the size of the refractive portion of the third lens and the size of the refractive portion of the fourth lens are quite different, and the third spacing element is usually difficult to cover the third lens due to the limitation of its dimensional versatility. The mounting part of the third lens and the fourth lens causes the above-mentioned unnecessary reflection and scattering to occur at the mounting part of the third lens and the fourth lens when the light propagates inside the VR eyepiece device. In particular, the stray light reflected and scattered at the mounting part of the fourth lens will continue to pass through the refractive part of the third lens, and part of the light will be imaged in the picture, which actually manifests as multiple ghost images and large-area light spots. The other part of the light will not be imaged but will still reach the human eye, which actually manifests as a bright edge of the picture. Since the ratio of the curvature radius of R6 and R7 has a certain range limit, the tolerance needs to be strictly controlled during the assembly process. If the assembly is not precise enough, the gap between the lenses may be uneven, which will cause stray light. 20≤CP3 / T34<31.7, a larger CP3 / T34 ratio may mean that higher precision is required during the assembly process to ensure the correct alignment between the lenses. If the assembly is not precise enough, the gap between the lenses may be uneven, causing stray light. Although T34 represents the on-axis distance, in actual assembly, the air gap between the lenses may be affected by various factors (such as temperature, humidity, vibration, etc.), causing the gap to change. 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.At this time, we control the ratio of (D3s-d3s) / CP3. By adjusting this ratio between 0.25 and 0.6, the geometric shape of the spacer element can be optimized, thereby reducing the scattering and reflection of light at the edge of the spacer element, and further reducing the generation of stray light. Specifically, the optimization of this ratio can help reduce the scattering of light on the eye side of the third spacer element (i.e., the side close to the fourth lens), because the appropriate inner and outer diameter difference can provide better light guidance, and guide the stray light between the third lens and the fourth lens to the third spacer element, thereby avoiding the mounting part of the third lens and the fourth lens. Usually, the spacer elements between the lenses have the function of absorbing light, thus blocking the stray light from entering the human eye.

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

[0014] With such a configuration, firstly, by controlling the ratio of L / TD, the overall structural compactness of the VR eyepiece device can be optimized while ensuring the optical performance. A smaller ratio value means that the lens barrel height is more compact relative to the total length of the lens group, which helps to reduce the volume and weight of the entire VR eyepiece device and improve portability and wearing comfort; secondly, an excessively long lens barrel length (i.e., a larger L value) will increase the risk of shaking of the lens group in the vertical direction perpendicular to the optical axis. When designing the lens group, the present application controls the ratio of L / TD within the above-mentioned range to help limit such shaking, thereby improving the stability and durability of the optical lens; finally, the L / TD ratio range limit can also maintain precise alignment between the lenses of the lens group during the manufacturing and assembly process of the VR eyepiece device, which helps to reduce aberrations and distortions caused by assembly errors and improve image clarity and quality.

[0015] 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, and the effective focal length f1 of the first lens and the eye side inner diameter d1s of the first spacer element satisfy the following relationship: 0.15 <d1s / f1<0.3。

[0016] By setting it this way, the light transmission between lens groups can be optimized by precisely controlling the ratio, and the light loss and distortion between lens groups can be reduced, thereby helping to improve the imaging quality, image clarity and sharpness, and color reproduction accuracy of the entire VR eyepiece device. During the lens assembly process, a reasonable d1s / f1 ratio also helps to maintain precise alignment between 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.

[0017] In one embodiment, the spacer element group also 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, and the inner diameter d1s of the eye side of the first spacer element, the outer diameter D1s of the eye side of the first spacer element and the effective radius DT12 of the image side surface of the first lens satisfy: 0.05<(D1s-d1s) / DT12<0.22.

[0018] In this way, the size and shape of the spacer element can be optimized 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 of the first lens, which helps to ensure a close fit between the spacer element group and the lens group, reduce the leakage and scattering of light between the lens groups, and thus improve the imaging quality of the optical system; in addition, a reasonable ratio range helps to maintain the precise alignment of the lens groups with the optical axis during the assembly process. By precisely controlling the size of the spacer element, image distortion and aberrations caused by assembly errors can be reduced, and the overall performance and stability of the lens can be improved; further, by adjusting the size and shape of the spacer element, a VR eyepiece device that adapts to different application scenarios can be designed: for example, in scenarios that require higher resolution or smaller volume, these requirements can be met by optimizing the design of the spacer element.

[0019] 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, and 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] With such a configuration, firstly, the ratio range ensures that the relative size relationship between the third spacing element CP3 and the distance EP13 from the first spacing element to the third spacing element is reasonable, which helps to reasonably allocate the positions of various elements in a limited space and avoids assembly difficulties caused by space waste or excessive compactness; secondly, reasonable spatial layout and element thickness help to reduce the reflection and scattering of light between elements, thereby reducing light loss, and helping to improve light utilization and imaging quality; thirdly, the ratio range helps to balance the focal length relationship between various spacing elements and ensure the focal length balance of the entire VR eyepiece device. This helps to achieve better imaging quality and smaller aberrations; finally, precise spatial layout and ratio range help to ensure the compatibility of the VR eyepiece device with other optical elements or components, thereby assisting in the integration and expansion of the VR eyepiece device. In addition, precise spatial layout and ratio range also help to simplify the manufacturing process, reduce costs, and make it more convenient for debugging and optimization of the optical system, thereby helping to achieve large-scale production and rapid delivery.

[0021] In one embodiment, the spacer element group further includes a fourth spacer element whose two ends are respectively abutted against the image side surface of the fourth lens and the eye side surface of the filter, and the axial distance EP34 from the image side surface of the third spacer element to the eye side surface of the fourth spacer element and the center thickness CT4 of the fourth lens satisfy the following relationship: 0.25 <EP34 / CT4<0.45。

[0022] With such a configuration, firstly, precise control of the ratio can ensure a reasonable distribution of space between the third spacing element and the fourth lens, which helps to achieve optimal optical performance and structural stability within a limited space, while avoiding assembly difficulties caused by space waste or excessive compactness; secondly, the ratio range enables the VR eyepiece device to achieve a relatively compact optical system design, which not only reduces the overall volume and weight of the VR eyepiece device, but also improves portability and wearing comfort; furthermore, the ratio range helps to balance the focal length relationship between the various elements, and focal length balance helps to improve the imaging quality and performance of the entire VR eyepiece device.

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

[0024] In this way, the ratio of the inner diameter d0s of the side of the lens barrel to the effective focal length f determines the field of view of the VR eyepiece device. First, within this ratio range, d0s is relatively large, so that the user can see a wider virtual scene through the VR eyepiece, which helps to enhance the user's sense of immersion and the sense of reality of the virtual experience, specifically: on the one hand, a larger d0s helps to reduce the blind spot of the field of view, so that the user can perceive the surrounding environment more comprehensively when watching the virtual scene, which helps to enhance the user's comfort and satisfaction, and reduce the discomfort caused by the limited field of view; on the other hand, a larger d0s helps to adapt to the eye distance and pupil distance requirements of different users, so that the VR eyepiece device can be more widely used in different user groups, and enhance the comfort and satisfaction of the user experience. Secondly, a reasonable ratio of d0s to f helps to reduce aberrations, including spherical aberration, coma, astigmatism, etc., wherein the reduction of aberrations helps to improve the image quality, making the virtual scene clearer and sharper. Furthermore, within this ratio range, the light can be more evenly distributed on the side of the lens barrel, which helps to reduce light loss and improve the utilization rate of light and the image quality.

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

[0026] In this way, by precisely controlling the ratio of the difference between d0s and d0m and the maximum height L of the lens barrel, the reasonable allocation of the internal space of the lens barrel can be ensured, which helps to achieve the best optical performance and structural stability in a limited space, while avoiding space waste or assembly difficulties caused by excessive compactness, that is, to achieve a relatively more compact optical system design, which not only reduces the overall volume and weight of the VR eyepiece device, but also improves the wearing comfort and portability. In addition, by adjusting the difference between d0s and d0m, the spatial layout and component size can be optimized, so as to flexibly adapt to different application scenarios and meet the needs of higher resolution, lower distortion or smaller volume.

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

[0028] With such a setting, firstly, the larger d0s relative to d01s means that the eye side of the main lens barrel can receive a wider range of light, which helps to reduce light loss and improve light utilization, thereby optimizing imaging quality; secondly, a reasonable d0s to d01s ratio helps to enhance the structural strength of the entire system, which makes the VR eyepiece device more durable and able to withstand greater shock and vibration; thirdly, the precise ratio helps to maintain precise alignment between various components during the assembly process, which reduces assembly errors and improves the stability and accuracy of the system.

[0029] In one embodiment, the spacer element group also includes a fourth spacer element whose two ends are respectively abutted against the image side surface of the fourth lens and the eye side surface of the filter, and the center thickness CP4 of the fourth spacer element and the axial distance BL from the image side surface of the fourth lens to the image side end surface satisfy: 0.1≤CP4 / BL<0.65.

[0030] With such a setting, by precisely controlling the ratio of CP4 to BL, the optical path design can be further optimized and aberrations (such as spherical aberration, coma, astigmatism, etc.) can be reduced, which helps to improve image clarity and sharpness and ensure imaging quality; secondly, a reasonable ratio of CP4 to BL helps to reduce reflection and scattering of light inside the lens barrel, thereby improving light utilization, which helps to enhance image brightness and contrast and improve the overall visual effect; in addition, a precise proportional relationship helps to maintain precise alignment between various components during the assembly process, which reduces assembly errors, improves the stability and accuracy of the system, and ensures consistency in imaging quality. The formation of such a compact and reasonable spatial layout can also help reduce the sense of oppression of the VR eyepiece device on the user, thereby reducing discomfort when worn for a long time and improving the user experience.

[0031] In one embodiment, the second lens is glued to the third lens to form a glue layer between the second lens and the third lens;

[0032] The refractive index of the adhesive layer is in the range of 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 in the range of greater than or equal to 0.095 and less than or equal to 0.256.

[0034] With such a configuration, firstly, the glued lens can reduce the air gap between the lenses, thereby reducing the possibility of light reflection and scattering on the lens surface; secondly, 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; thirdly, the design of the glued lens helps to realize more complex optical systems, such as achromatic lens groups, to correct the chromatic aberration of light of 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 VR eyepiece devices 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 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 consistency of optical performance of each VR eyepiece device.

[0035] In one embodiment, the thickness of the quarter wave plate is in the range of 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 in the range of 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 in the range of greater than or equal to 0.095 and less than or equal to 0.105.

[0038] With this setting, by precisely controlling the thickness of the quarter-wave plate, polarizing reflective film and adhesive layer, the optical path design can be further optimized to meet the requirements of VR eyepiece devices for high resolution, low distortion, etc.

[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] With such a configuration, firstly, by adjusting the ratio range of f1 / (f2+f3), the focal length of the entire system can be flexibly adjusted to adapt to different application scenarios and requirements. A reasonable ratio range of f1 / (f2+f3) helps to balance the focal length relationship between the first lens and the cemented lens group, thereby improving the resolution of the entire VR eyepiece device; secondly, the design of the cemented lens helps to reduce the aberration and distortion between the lens groups and improve the clarity and sharpness of the image, which is specifically manifested in that: by precisely controlling the refractive index Ng of the glue layer, the refraction path of the light can be further optimized and the aberration can be reduced; furthermore, the design of the cemented lens can also achieve color correction, reduce the chromatic aberration between lights of different wavelengths, and improve the image. The color reproduction degree is specifically manifested as follows: the polarized reflective film can selectively reflect or absorb light waves in a specific direction to improve the polarization efficiency of the light, and the quarter-wave plate can change the polarization state of the light wave to further enhance the polarization effect. By precisely controlling the refractive index NRP of the polarized reflective film and the refractive index NQWP of the quarter-wave plate, the generation of 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: 1.9≤V2 / V3<2.6.

[0042] In this arrangement, firstly, the second lens is a convex lens, and the third lens has a negative focal power, that is, a concave lens. The spherical aberration of the two lenses is opposite. By gluing the two together, part of the spherical aberration can be offset, thereby obtaining a clearer image. In other words, the design of the glued lens helps to correct the spherical aberration more accurately to improve the image quality. Secondly, the Abbe number (V value) is an indicator of the dispersion ability of the lens material. By selecting lens materials with different Abbe numbers for gluing, the chromatic aberration can be corrected, so that the imaging of the lens combination at different wavelengths is more consistent. Furthermore, within the above-given V2 / V3 range, the lens combination may have a better chromatic aberration correction effect, and the glued lens can reduce the aberration and chromatic aberration, thereby improving the clarity of the image. Finally, by optimizing the shape, material and refractive index of the glue layer of the lens, the image quality can be further improved. In the field of photography and videography, this lens combination can be applied to high-end cameras and lenses to improve the shooting quality. It can reduce aberration and chromatic aberration, making the photos and videos taken clearer and more realistic.

[0043] In one embodiment, the spacer element group also 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, and the on-axis distance EP01 from the eye side end face to the eye side surface 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: 0.6<(EP01+CP1) / (CT1+CTRP+CTQWP)<1.8.

[0044] With such arrangement, firstly, by precisely controlling the on-axis distance EP01 from the eye side of the lens barrel to the eye side of the first spacing element, the center thickness CP1 of the first spacing 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, a more compact optical system design can be achieved; secondly, the ratio range ensures that the space allocation between the various elements is relatively reasonable, avoiding the assembly difficulties caused by space waste or excessive compactness, which is helpful to achieve the best optical performance and structural stability in a limited space; thirdly, the reasonable space layout and element thickness are helpful to reduce the reflection, scattering and absorption of light between the elements, thereby This reduces light loss, improves light utilization and imaging quality; further, 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 glued lenses and polarization elements helps to achieve color correction, reduce chromatic aberration between light of different wavelengths, and help improve the color reproduction and saturation of the image; finally, the precise spatial layout and proportional range not only helps to maintain precise alignment between the various components during the assembly process, reduce assembly errors, and improve the stability and accuracy of the system, but also helps to simplify the manufacturing process, reduce manufacturing costs, and help achieve large-scale 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, 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 and the axial distance Tr3r6 from the eye side surface of the second lens to the image side surface of the third lens satisfy: 0.35 <EP13 / Tr3r6<0.7。

[0046] With such an arrangement, firstly, by precisely controlling the on-axis distance EP13 from the image side of the first spacing element to the eye side of the third spacing element and the on-axis distance Tr3r6 from the eye side of the second lens to the image side of the third lens, a more compact optical system design can be achieved. This compact design helps to reduce the overall volume and weight of the VR eyepiece device and improve the wearing comfort and portability; secondly, the proportional range ensures that the space distribution between the various elements is relatively reasonable, avoiding space waste or assembly difficulties caused by excessive compactness, which helps to achieve optimal optical performance and structural stability in a limited space; further, by precisely controlling the position and distance of each element, the optical path design can be optimized and aberrations and distortions can be reduced, which helps to achieve clearer and sharper images; finally, by adjusting the position and distance of each element, different application scenarios and requirements can be flexibly adapted: for example, in a VR eyepiece device that requires higher resolution, lower distortion or smaller volume, these requirements can be met by optimizing the spatial layout and element distance, and the precise spatial layout and proportional range help to simplify the manufacturing process and reduce manufacturing costs, thereby achieving large-scale production and rapid delivery. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of the structure of a VR eyepiece device in an embodiment provided in this application;

[0048] Figure 2A Schematic diagram of the structure of the VR eyepiece device in Example 1 under working condition 1-1;

[0049] Figure 2B Schematic diagram of the structure of the VR eyepiece device in Example 1 under working condition 1-2;

[0050] Figure 2C Schematic diagram of the structure of the VR eyepiece device in Example 1 under working conditions 1-3;

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

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

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

[0054] Figure 4A Schematic diagram of the structure of the VR eyepiece device in Example 2 under working condition 2-1;

[0055] Figure 4B Schematic diagram of the structure of the VR eyepiece device in Example 2 under working condition 2-2;

[0056] Figure 4C Schematic diagram of the structure of the VR eyepiece device in Example 2 under working condition 2-3;

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

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

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

[0060] Fig. 6A Schematic diagram of the structure of the VR eyepiece device in Example 3 under working condition 3-1;

[0061] Figure 6B Schematic diagram of the structure of the VR eyepiece device in Example 3 under working condition 3-2;

[0062] Figure 6C Schematic diagram of the structure of the VR eyepiece device in Example 3 under working condition 3-3;

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

[0064] Figure 7B 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] Fig. 8A This is an MTF curve diagram of the VR eyepiece device in Example 2 under working condition 2-2;

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

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

[0069] Fig. 9 Schematic diagram of the optical path of effective light and stray light in the VR eyepiece device.

[0070] Reference numerals:

[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 DESCRIPTION

[0072] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0073] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0074] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0075] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0076] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0077] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0078] With the rapid development of virtual reality technology, the performance of VR eyepieces, as the core components of virtual reality equipment, directly affects the user's immersion and experience. Traditional VR eyepieces have problems such as narrow field of view, severe distortion, and insufficient comfort. Based on this, it is particularly important to develop a VR eyepiece device with high definition, wide viewing angle, low distortion, and comfortable wearing.

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

[0080] See also Figure 1 , FIG. 8A to FIG. 8C and Fig. 9 , Figure 1 This is a schematic diagram of the structure of a VR eyepiece device in an embodiment provided in this application. Fig. 8A is the MTF curve diagram of the VR eyepiece device in Example 2 under working condition 2-2, Figure 8B This is the MTF curve diagram of the VR eyepiece device in Example 2 when the parameter (D3s-d3s) / CP3 is 0.1 in the modified working condition 2-2. Figure 8C This is an MTF curve diagram of the VR eyepiece device in Example 2 when the parameter (D3s-d3s) / CP3 is 1 in the modified working condition 2-2, Fig. 9Schematic diagram of the optical path of effective light and stray light in a VR eyepiece device. The VR eyepiece device provided in the present application includes a lens barrel P0 having 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 installed on the lens barrel P0 from the eye-side end face to the image-side end face and arranged on the same optical axis to form a clear optical path, the inner annular surface of the lens barrel P0 is stepped to adapt to the sizes of the first to fourth lenses L4, the image-side surface of the third lens L3 is a convex surface convexly arranged along the optical axis toward the fourth lens L4, the eye-side surface of the fourth lens L4 is a convex surface convexly arranged along the optical axis toward the third lens L3, 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, a second lens L2, a third lens L3, a fourth lens L4, and a filter L5 located between the third lens L3 and the fourth lens L4 and abutting against the image-side surface of the third lens L3. The third spacing element P3 on the surface and the fourth spacing element P4 whose two ends are respectively abutted against the image side surface of the fourth lens L4 and the eye side surface of the filter L5; the eye side surface and the image side surface of the first lens L1 are spherical surfaces, the eye side surface and the image side surface of the second lens L2 are spherical surfaces, which is helpful to reduce aberrations, the eye side surface and the image side surface of the third lens L3 are aspherical surfaces, and the eye side surface and the image side surface of the fourth lens L4 are aspherical surfaces, which is helpful to further correct high-order aberrations and ensure high resolution and sharpness of the image; the optical power of the third lens L3 is negative; the image side surface of the first lens L1 is provided with a polarizing reflective film and a quarter-wave plate to eliminate reflected light and glare, and the image side surface of the third lens L3 is provided with a semi-reflective and semi-transparent film to achieve more complex imaging effects, such as virtual reality (VR) function or adjusting light distribution to optimize the field of view. The curvature radius R6 of the image side surface of the third lens L3 and the curvature radius R7 of the eye side surface of the fourth lens L4 satisfy: -2.60≤R6 / R7<-0.5, preferably: -2.60≤R6 / R7<-1.65; the center thickness CP3 of the third spacer element 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: 20≤CP3 / T34<31.7. However, under this condition, the light propagation between the two lens surfaces may become complicated.In particular, when the air gap between them (such as the gap formed by the third spacing element P3) is small, unnecessary reflection and scattering may occur when the light passes through the two lens surfaces. Specifically, the lens usually includes a refractive portion for refraction and a mounting portion for abutting and assembling with the spacing element and the lens barrel. The eye side and the image side of the lens are usually located in the refractive portion of the lens. Based on this, the diameters of the refractive portions of different lenses are also different. For the VR eyepiece device involved in the present application, the size of the refractive portion of the third lens L3 and the size of the refractive portion of the fourth lens L4 are quite different, and the third spacing element P3 is usually difficult to cover the third lens due to the limitation of its dimensional versatility. The mounting part of the third lens L3 and the fourth lens L4 causes the above-mentioned unnecessary reflection and scattering to occur at the mounting part of the third lens L3 and the fourth lens L4 when the light propagates inside the VR eyepiece device. In particular, the stray light reflected and scattered at the mounting part of the fourth lens L4 will continue to pass through the refractive part of the third lens L3, and part of the light will be imaged in the picture, which actually manifests as multiple ghost images and large-area light spots. The other part of the light will not be imaged but will still reach the human eye, which actually manifests as a bright edge of the picture. Since the ratio of the radius of curvature of R6 and R7 has a certain range limit, the tolerance needs to be strictly controlled during the assembly process. If the assembly is not precise enough, the gap between the lenses may be uneven, which will cause stray light. A larger CP3 / T34 ratio may mean that higher precision is required during the assembly process to ensure the correct alignment between the lenses. If the assembly is not precise enough, the gap between the lenses may be uneven, causing stray light. Although T34 represents the on-axis distance, in actual assembly, the air gap between the lenses may be affected by various factors (such as temperature, humidity, vibration, etc.), causing the gap to change. If the ratio of CP3 / T34 is too large, the effect of the spacing change on light propagation may be more significant, thereby increasing the generation of stray light. Therefore, in the VR eyepiece device provided in the present application, the inner diameter d3s of the eye side of the third spacing element P3, the outer diameter D3s of the eye side of the third spacing element P3, and the center thickness CP3 of the third spacing element P3 also 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, thus avoiding the mounting parts of these two lenses, the third lens L3 and the fourth lens L4. Generally, 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), and blocking the stray light from entering the human eye image to improve the image quality. Exemplarily, as... FIG. 8A to FIG. 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 also 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 when propagating between the lens groups, and further improve the imaging quality, image clarity and 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 satisfying: 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 by 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 on the optical axis during the assembly process. By precisely controlling the dimensions of the spacer elements, image distortion and aberration 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 where higher resolution or smaller volume is required, these requirements can be met by optimizing the design of the spacer elements.

[0084] Optionally, to reasonably allocate the positions of the respective elements for convenient assembly and reduce light loss, in an embodiment provided by 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 aberration. 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 make it more convenient for 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 the respective elements, and the 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 sense of reality, 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 field of view blind area and adapt to the interpupillary 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 utilization rate of light, and improve the 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, and 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 polarizing reflective film, quarter-wave plate, and semi-transparent 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 polarizing 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-transparent 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 both the polarizing reflective film and the quarter-wave plate are 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. This 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 the two ends of the second spacer element respectively abut 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 < f1 / (f2 + f3) ≤ 0.4. Combining the refraction of light by the glued lens and the film layer can 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 the lens groups, improve the utilization rate of light. By precisely controlling the refractive index and thickness of each element, and optimizing the ratio range of f1 / (f2 + f3), it is also easier to realize the debugging and optimization of the system.

[0093] Optionally, in order to correct chromatic aberration, in an embodiment provided in the present 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 satisfy: 2.1≤V2 / V3<2.6. Further, with the spherical aberration compensation effect between the cemented lens and 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 in a limited space, in an embodiment provided in the present application, the on-axis distance EP01 from the eye-side end face to the eye-side face of the first spacing element P1, the center thickness CP1 of the first spacing 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 relationship: 0.6<(EP01+CP1) / (CT1+CTRP+CTQWP)<1.8.

[0095] Optionally, in order to achieve the compactness of the structure of the VR eyepiece device as much as possible under the premise of achieving assembly, in one embodiment provided in the present application, the axial distance EP13 from the image side surface of the first spacing element P1 to the eye side surface of the third spacing element P3 and the axial distance Tr3r6 from the eye side surface of the second lens L2 to the image side surface of the third lens L3 satisfy the following relationship: 0.35 <EP13 / Tr3r6<0.7。

[0096] Some specific but non-limiting examples of the embodiments of the present application are described in more detail below with reference to the accompanying drawings. It is understood that any one of the following examples 1 to 3 is applicable to all embodiments of the present application.

[0097] For the convenience of description, in the following examples, STO represents the surface of the aperture, 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, which reflects the light transmission capacity 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] In addition, the surface numbers of the functional surfaces of the light path along the reverse direction of the light path are defined as S1 to SN in sequence, where S1 represents the surface number of the first functional surface of the light path along the reverse direction of the light path, and SN represents the surface number of the Nth functional surface of the light path along the reverse direction of the light path.

[0099] See also Figure 2A , Figure 4A and Fig. 6A, the three figures respectively show the structural schematic diagrams of the VR eyepiece device in the three embodiments provided by the present 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 bonding layer, S7 is the bonding surface between the bonding layer and the third lens L3, S8 is the bonding surface between the third lens L3 and the semi-reflective and semi-transparent film, S9 is the eye side surface of the fourth lens L4, S10 is the image side surface of the fourth lens L4, S11 is the eye side surface of the filter L5, and S12 is the image side surface of the filter L5.

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

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

[0102]

[0103] In the above formula, x represents the surface sag 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] Embodiment 1

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

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

[0107] Table 1

[0108]

[0109]

[0110] Table 2

[0111] Face number A4 A6 A8 S7 8.427E-06 2.123E-08 2.343E-11 S8 1.101E-06 -7.645E-10 2.372E-12 S9 2.517E-05 1.674E-07 -7.384E-11 S10 8.126E-05 -3.861E-09 -1.005E-09

[0112] After simulation test, the results are as follows Figure 3A to Figure 3C As shown, Figure 3A to Figure 3C They are the axial chromatic aberration curve, astigmatism curve and distortion curve of the VR eyepiece device. FIG. 3A to FIG. 3C It can be seen that the VR eyepiece device of Example 1 can achieve good imaging quality.

[0113] Embodiment 2

[0114] like Figure 4A to Figure 4C As shown, Figure 4A to Figure 4C The following are schematic diagrams of the structure of the VR eyepiece device under three working conditions provided in Example 2. Figure 4A and 4B In the corresponding working conditions 2-1 and 2-2, a stop step is provided on the eye side end surface of the lens barrel P0, and the stop step abuts against the eye side surface of the first lens L1 to limit the first lens L1 axially together with the first spacing element P1. Figure 4C In the corresponding working condition 2-3, the VR eyepiece device further includes a first auxiliary spacing element P01 located on the eye side end surface of the lens barrel P0 and sleeved on the outer annular surface of the lens barrel P0, and the first auxiliary spacing element P01 is spaced apart from the first lens L1. Figure 4A In the corresponding working condition 2-1, the VR eyepiece device further includes a third auxiliary spacing element P3b whose two ends are respectively abutted against the image side surface of the third spacing element and the eye side surface of the fourth lens L4; in addition, the two ends of the first spacing element P1 are respectively abutted against the image side surface and the eye side surface of the first lens L1. Figure 4B and Figure 4C In the corresponding working conditions 2-2 and 2-3, two ends of the first spacing unit are respectively in contact with the image side surface of the first lens L1 and the eye side surface of the third lens L3, and the second lens L2 is spaced apart from the first lens L1.

[0115] Table 3 gives the design data of the VR eyepiece device in Example 2, and Table 4 gives the high-order coefficient parameters of the four surfaces S7 to S10.

[0116] Table 3

[0117]

[0118]

[0119] Table 4

[0120] Face number A4 A6 A8 S7 -3.720E-07 1.087E-07 -4.585E-11 S8 -6.714E-07 1.738E-08 -3.612E-11 S9 1.679E-04 -1.673E-06 2.174E-09 S10 -2.134E-04 1.457E-06 -5.196E-09

[0121] After simulation test, the results are as follows Figure 5A to Figure 5C As shown, Figure 5A to Figure 5C They are the axial chromatic aberration curve, astigmatism curve and distortion curve of the VR eyepiece device. FIG. 5A to FIG. 5C It can be seen that the VR eyepiece device of Example 2 can achieve good imaging quality.

[0122] Embodiment 3

[0123] like Figure 6A to Figure 6C As shown, Figure 6A to Figure 6C The following are structural schematic diagrams of the VR eyepiece device under three working conditions provided in Example 3. Specifically, Fig. 6A and 6B In the corresponding working conditions 3-1 and 3-2, a stop step is provided on the eye side end surface of the lens barrel P0, and the stop step abuts against the eye side surface of the first lens L1 to limit the first lens L1 axially together with the first spacing element P1. Figure 6C In the corresponding working condition 3-3, the VR eyepiece device further includes a first auxiliary spacing element P01 located on the eye side end surface of the lens barrel P0 and sleeved on the outer annular surface of the lens barrel P0, and the first auxiliary spacing element P01 is spaced apart from the first lens L1. In the three working conditions, the VR eyepiece device further includes a third auxiliary spacing element P3b whose two ends are respectively abutted against the image side surface of the third spacing unit and the eye side surface of the fourth lens L4. Fig. 6A In the corresponding working condition 3-1, the two ends of the first spacer element P1 are respectively in contact with the image side surface of the first lens L1 and the eye side surface of the second lens L2, and Figure 6B and Figure 6C In the corresponding working conditions 3-2 and 3-3, two ends of the first spacing element P1 are respectively in contact with the image side surface of the first lens L1 and the eye side surface of the third lens L3, and the second lens L2 is spaced apart from the first lens L1.

[0124] Table 5 gives the design data of the VR eyepiece device in Example 3, and Table 4 gives the high-order coefficient parameters of the four surfaces S7 to S10.

[0125] Table 5

[0126]

[0127]

[0128] Table 6

[0129] Face number A4 A6 A8 S7 -8.022E-07 2.984E-08 2.123E-11 S8 1.326E-06 3.888E-09 1.999E-12 S9 2.642E-05 -8.866E-07 5.384E-09 S10 -9.599E-06 -2.476E-07 9.300E-09

[0130] After simulation test, the results are as follows Figure 7A to Figure 7C As shown, Figure 7A to Figure 7C They are the axial chromatic aberration curve, astigmatism curve and distortion curve of the VR eyepiece device. 7A to 7C It can be seen that the VR eyepiece device of Example 3 can achieve good imaging quality.

[0131] The optical parameters of the above three embodiments are shown in Table 7.

[0132] Table 7

[0133] Example parameters 1 2 3 HFOV 43.00 41.00 38.70 FNO 3.11 3.47 3.07 TD 13.34 13.05 13.30 f 12.46 13.90 12.28 f1 164.17 186.53 124.81 f2 1692.35 499.83 -2696.27 f3 -26.37 -28.42 -26.07 f4 27.54 -600.00 29.02

[0134] See also Figure 1 ,The parameters involved in the VR eyepiece device under various working conditions are shown in Table 8.

[0135] Table 8

[0136]

[0137]

[0138] The conditional formulas of the VR eyepiece device under various working conditions are shown in Table 9.

[0139] Table 9

[0140] Conditional / Example Combination 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 R6 / R7 -1.97 -1.97 -1.97 -2.6 -2.6 -2.6 -1.68 -1.68 -1.68 CP3 / T34 28.73 28.73 28.73 20.01 21.37 21.47 31.68 26.37 26.37 (D3s-d3s) / CP3 0.43 0.56 0.43 0.46 0.43 0.35 0.29 0.35 0.39 L / TD 1.17 1.12 1.21 1.41 1.41 1.19 1.26 1.1 1.1 d1s / f1 0.17 0.19 0.2 0.16 0.17 0.18 0.25 0.24 0.26 (D1s-d1s) / DT12 0.21 0.21 0.21 0.13 0.13 0.2 0.18 0.08 0.18 f1 / (f2+f3) 0.1 0.1 0.1 0.4 0.4 0.4 -0.05 -0.05 -0.05 V2 / V3 2.54 2.54 2.54 2.43 2.43 2.43 2.18 2.18 2.18 (EP01+CP1) / (CT1+CTRP+CTQWP) 1.55 1.55 1.77 1.35 1.75 1.58 0.63 1.07 0.93 EP13 / Tr3r6 0.49 0.49 0.49 0.54 0.39 0.39 0.67 0.56 0.56 CP3 / EP13 2.07 2.07 2.07 1.16 1.73 1.74 2.03 2.01 2.01 EP34 / CT4 0.26 0.26 0.26 0.44 0.37 0.37 0.34 0.43 0.43 d0s / f 2.12 2.12 2.92 1.66 1.66 2.55 2.02 2.02 2.7 (d0s-d0m) / L -0.85 -0.73 0.96 -0.88 -0.88 0.82 -0.74 -0.69 0.86 d0s / d01s / / 1.49 / / 1.62 / / 1.4 CP4 / BL 0.24 0.35 0.23 0.33 0.34 0.63 0.1 0.24 0.21

[0141] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0142] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A VR eyepiece device, characterized in that: include: A lens barrel having an eye-side end surface and an image-side end surface; a lens group, comprising a first lens, a second lens, a third lens, a fourth lens and a filter which are sequentially installed in the lens barrel from the eye side end surface to the image side end surface and arranged on the same optical axis, wherein the image side surface of the third lens is a convex surface convexly arranged along the optical axis toward the fourth lens, and the eye side surface of the fourth lens is a convex surface convexly arranged along the optical axis toward the third lens; and a spacer element group, comprising a third spacer element located between the third lens and the fourth lens and abutting against the image side surface of the third lens; The eye side surface and the image side surface of the first lens are spherical surfaces, the eye side surface and the image side surface of the second lens are spherical surfaces, the eye side surface and the image side surface of the third lens are aspherical surfaces, and the eye side surface and the image side surface of the fourth lens are aspherical surfaces; the optical power of the first lens is positive, and the optical power of the third lens is negative; the image side surface of the first lens is attached with a polarizing reflection film and a quarter wave plate, and the image side surface of the third lens is attached with a semi-reflective and semi-transparent film; The curvature radius R6 of the image side surface of the third lens and the curvature radius R7 of the eye side surface of the fourth lens satisfy: -2.60≤R6 / R7<-0.5; The central thickness CP3 of the third spacer element and the axial distance T34 from the image side surface of the third lens to the eye side surface of the fourth lens satisfy the following: 20≤CP3 / T34<31.7; The inner diameter d3s of the third spacer element at the front side, the outer diameter D3s of the third spacer element at the front side and the center thickness CP3 of the third spacer element satisfy the following: 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: 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, and the effective focal length f1 of the first lens and the eye side inner diameter d1s of the first spacer element satisfy the following relationship: 0.15 <d1s / f1<0.3。 4. The VR eyepiece device according to claim 1, characterized in that: The spacer element group also 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, and the inner diameter d1s of the eye side of the first spacer element, the outer diameter D1s of the eye side of the first spacer element and the effective radius DT12 of the image side surface of the first lens satisfy: 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, and 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 are respectively abutted against the image side surface of the fourth lens and the eye side surface of the filter, and the axial distance EP34 from the image side surface of the third spacer element to 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。 7. The VR eyepiece device according to claim 1, characterized in that: The inner diameter d0s of the eye side end surface and the effective focal length f of the eyepiece device satisfy: 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 surface, the inner diameter d0m of the image-side end surface and the maximum height L of the lens barrel satisfy the following conditions: 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 comprises an auxiliary lens barrel, and the inner diameter d01s of the eye side face of the auxiliary lens barrel, the inner diameter d0s of the eye side end face and the inner diameter d0m of the image side end face satisfy: 1.4≤d0s / d01s<1.

65.

10. The VR eyepiece device according to claim 1, characterized in that: The spacer element group also includes a fourth spacer element whose two ends are respectively abutted against the image side surface of the fourth lens and the eye side surface of the filter, and the center thickness CP4 of the fourth spacer element and the axial distance BL from the image side surface of the fourth lens to the image side end surface satisfy the following: 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 with the third lens to form a cementing layer between the second lens and the third lens; The refractive index of the adhesive layer is in the range of greater than or equal to 1.45 and less than or equal to 1.55; and / or The thickness of the adhesive layer is in the range of 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 in the range of 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 in the range of 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 in the range of 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: -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: 1.9≤V2 / V3<2.

6.

15. The VR eyepiece device according to claim 14, characterized in that: The spacer element group also 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, and the on-axis distance EP01 from the eye side end face to the eye side surface 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, and an axial distance EP13 from the image side surface of the first spacer element to the eye side surface of the third spacer element and an axial distance Tr3r6 from the eye side surface of the second lens to the image side surface of the third lens satisfy the following conditions: 0.35 <EP13 / Tr3r6<0.7。

Images