VR optical system

Abstract

The present invention provides a VR optical system. The VR optical system sequentially includes a first optical element group, a second optical element group, and a third optical element group from the human eye to the display. Among them, the first optical element group at least includes a first lens; the second optical element group at least includes a second lens; the third optical element group includes a third lens, and the third lens has a focal power; the first optical element group or the second optical element group further includes a reflective polarizer and a quarter-wave retarder; wherein, the lens has a surface close to the human eye side and a surface close to the display side, and at least one surface of the first lens, the second lens, and the third lens has a partial reflection layer; the effective focal length FG1 of the first optical element group, the effective focal length FG2 of the second optical element group, and the effective focal length group FG3 of the third optical element group satisfy: 0 < FG1 / |FG2 + FG3| < 4.0. The present invention solves the problem in the prior art that the VR optical system cannot兼顾miniaturization and high image quality. It should be noted that the Chinese phrase "兼顾" in the original text is misspelled. The correct word should be "兼顾", which means "take both into consideration" or "give consideration to both". The translated text above uses the correct expression "give consideration to both" to convey the intended meaning.

Description

Technical Field

[0001] This invention relates to the field of optical imaging equipment technology, and more specifically, to a VR optical system. Background Technology

[0002] With the rise of AR and VR, VR optical devices are gradually entering the public eye, and consumers' expectations for VR optics are increasing, leading to a gradual increase in the consumption of VR optical devices. Currently, VR optical devices are still under development, and there are still many areas that need improvement, such as their size, weight, and image quality.

[0003] Typically, improving image quality involves increasing the number of lenses in an optical lens, which effectively balances various aberrations and enhances image quality. However, as VR optical devices strive for miniaturization and weight reduction, VR optical systems also need to be miniaturized and lightweight. Increasing the number of lenses increases the size and weight of the VR optical system, while reducing the number of lenses compromises image quality. This makes it difficult for VR optical systems to simultaneously meet the requirements of miniaturization and high image quality. Furthermore, the smaller size of lenses used in VR optical systems increases the difficulty of lens manufacturing, resulting in less design freedom and hindering improvements in image quality.

[0004] In other words, existing VR optical systems suffer from the problem of not being able to simultaneously achieve miniaturization and high image quality. Summary of the Invention

[0005] The main objective of this invention is to provide a VR optical system that solves the problem that existing VR optical systems cannot simultaneously achieve miniaturization and high image quality.

[0006] To achieve the above objectives, according to one aspect of the present invention, a VR optical system is provided, comprising, sequentially from the human eye to the display, a first optical element group, a second optical element group, and a third optical element group, wherein the first optical element group includes at least a first lens; the second optical element group includes at least a second lens; the third optical element group includes a third lens having optical power; the first optical element group or the second optical element group further includes a reflective polarizer and a quarter-retarder; wherein the lens has a surface near the human eye and a surface near the display, and at least one surface of the first lens, the second lens, and the third lens has a partially reflective layer; the effective focal lengths FG1 of the first optical element group, FG2 of the second optical element group, and FG3 of the third optical element group satisfy the following: 0 <FG1 / |FG2+FG3|<4.0。

[0007] Furthermore, when the first optical element group includes a reflective polarizer and a quarter-retarder, the reflective polarizer and the quarter-retarder are bonded together, and the first lens is bonded together with the reflective polarizer on the side surface near the display.

[0008] Furthermore, when the second optical element group includes a reflective polarizer and a quarter-retarder, the reflective polarizer is bonded to the quarter-retarder, and the second lens is bonded to the quarter-retarder on the surface near the human eye.

[0009] Furthermore, the center thickness CT2 of the second lens on the optical axis of the VR optical system and the center thickness CT3 of the third lens on the optical axis satisfy the following condition: 0.25 <CT2 / CT3<7.2。

[0010] Furthermore, the third lens has a convex surface near the display side surface.

[0011] Furthermore, the radius of curvature R22 of the second lens near the display side surface and the radius of curvature R31 of the third lens near the human eye side surface satisfy the following relationship: 0.76 <R22 / R31<11.1。

[0012] Furthermore, the effective focal length FG1 of the first optical element group and the effective focal length f of the VR optical system satisfy: 2.4 <FG1 / f<16.4。

[0013] Furthermore, the refractive indices of the first lens, the second lens, and the third lens are greater than 1.5 and less than 1.7.

[0014] Furthermore, the distance T12 between the first lens near the display side surface and the second lens near the human eye side surface on the optical axis of the VR optical system, and the distance T23 between the second lens near the display side surface and the third lens near the human eye side surface on the optical axis, satisfy the following condition: 1.0 <T23 / T12<3.8。

[0015] Furthermore, the distance TD between the surface of the first optical element group near the human eye and the surface of the third lens near the display on the optical axis of the VR optical system, and the center thickness CT1 of the first lens on the optical axis, satisfy: 4.6 <TD / CT1<7.2。

[0016] Furthermore, the radius of curvature R11 of the first lens near the human eye side surface and the radius of curvature R22 of the second lens near the display side surface satisfy: 0.6 < |R11+R22| / (R11-R22) < 5.8.

[0017] Furthermore, the center thickness CT3 of the third lens on the optical axis of the VR optical system satisfies the following condition with respect to the center thickness CTQ of the quarter-retarder on the optical axis: 10≦CT3 / CTQ<61.4.

[0018] Furthermore, the first optical element group has positive optical power.

[0019] According to another aspect of the present invention, a VR optical system is provided, comprising, sequentially from the human eye to the display, a first optical element group, a second optical element group, and a third optical element group, wherein the first optical element group includes at least a first lens; the second optical element group includes at least a second lens; the third optical element group includes a third lens having optical power; the first or second optical element group further includes a reflective polarizer and a quarter-retarder; wherein the lenses have a surface near the human eye and a surface near the display, and at least one surface of the first, second, and third lenses has a partially reflective layer; the effective focal length FG1 of the first optical element group satisfies the following relationship with the effective focal length f of the VR optical system: 2.4 <FG1 / f<16.4。

[0020] Furthermore, when the first optical element group includes a reflective polarizer and a quarter-retarder, the reflective polarizer and the quarter-retarder are bonded together, and the first lens is bonded together with the reflective polarizer on the side surface near the display.

[0021] Furthermore, when the second optical element group includes a reflective polarizer and a quarter-retarder, the reflective polarizer is bonded to the quarter-retarder, and the second lens is bonded to the quarter-retarder on the surface near the human eye.

[0022] Furthermore, the center thickness CT2 of the second lens on the optical axis of the VR optical system and the center thickness CT3 of the third lens on the optical axis satisfy the following condition: 0.25 <CT2 / CT3<7.2。

[0023] Furthermore, the third lens has a convex surface near the display side surface.

[0024] Furthermore, the radius of curvature R22 of the second lens near the display side surface and the radius of curvature R31 of the third lens near the human eye side surface satisfy the following relationship: 0.76 <R22 / R31<11.1。

[0025] Furthermore, the refractive indices of the first lens, the second lens, and the third lens are greater than 1.5 and less than 1.7.

[0026] Furthermore, the distance T12 between the first lens near the display side surface and the second lens near the human eye side surface on the optical axis of the VR optical system, and the distance T23 between the second lens near the display side surface and the third lens near the human eye side surface on the optical axis, satisfy the following condition: 1.0 <T23 / T12<3.8。

[0027] Furthermore, the distance TD between the surface of the first optical element group near the human eye and the surface of the third lens near the display on the optical axis of the VR optical system, and the center thickness CT1 of the first lens on the optical axis, satisfy: 4.6 <TD / CT1<7.2。

[0028] Furthermore, the radius of curvature R11 of the first lens near the human eye side surface and the radius of curvature R22 of the second lens near the display side surface satisfy the following condition: 0.6 < |R11+R22| / (R11-R22) < 5.8.

[0029] Furthermore, the center thickness CT3 of the third lens on the optical axis of the VR optical system satisfies the following condition with respect to the center thickness CTQ of the quarter-retarder on the optical axis: 10≦CT3 / CTQ<61.4.

[0030] Furthermore, the first optical element group has positive optical power.

[0031] Applying the technical solution of this invention, the VR optical system sequentially includes a first optical element group, a second optical element group, and a third optical element group from the human eye to the display. The first optical element group includes at least a first lens; the second optical element group includes at least a second lens; and the third optical element group includes a third lens, which has optical power. The first or second optical element group further includes a reflective polarizer and a quarter-retarder. Each lens has a surface near the human eye and a surface near the display. At least one surface of the first, second, and third lenses has a partially reflective layer. The effective focal lengths FG1 of the first optical element group, FG2 of the second optical element group, and FG3 of the third optical element group satisfy the following: 0 <FG1 / |FG2+FG3|<4.0。

[0032] By incorporating reflective polarizers, quarter-retarders, and a partial reflective layer into the VR optical system, the principle of polarization is used to fold the optical path, thereby increasing the optical path length while reducing the overall length of the VR optical system. This approach facilitates both high image quality and miniaturization. Placing the reflective polarizer and quarter-retarder within the first or second optical element group positions the optical path fold closer to the human eye, increasing the folding distance and effectively extending the optical path. This, in turn, enhances the imaging quality of the VR optical system while simultaneously shortening its length. Furthermore, limiting the focal lengths of the first, second, and third optical element groups rationally allocates the system's optical power, further improving the imaging quality and achieving a balance between miniaturization and high image quality. Attached Figure Description

[0033] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0034] Figure 1 A schematic diagram of a VR optical system according to Example 1 of the present invention is shown;

[0035] Figures 2 to 4 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Example 1 of the present invention are shown respectively.

[0036] Figure 5 A schematic diagram of the VR optical system of Example 2 of the present invention is shown;

[0037] Figures 6 to 8 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Example 2 of the present invention are shown respectively.

[0038] Figure 9 A schematic diagram of the VR optical system of Example 3 of the present invention is shown;

[0039] Figures 10 to 12 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Example 3 of the present invention are shown respectively;

[0040] Figure 13 A schematic diagram of the VR optical system of Example 4 of the present invention is shown;

[0041] Figures 14 to 16 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Example 4 of the present invention are shown respectively;

[0042] Figure 17 A schematic diagram of the VR optical system of Example 5 of the present invention is shown;

[0043] Figures 18 to 20 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Example 5 of the present invention are shown respectively.

[0044] The above figures include the following reference numerals:

[0045] STO, human eye; E1, first lens; PR, reflective polarizer; QWP, quarter-retarder; E2, second lens; E3, third lens; IMG, image plane. Detailed Implementation

[0046] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0048] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0049] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0050] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not drawn strictly to scale.

[0051] In this paper, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object side is called the object-side surface of the lens, and the surface of each lens closest to the image side is called the image-side surface of the lens. The surface shape in the paraxial region can be determined according to the judgment method commonly used by those knowledgeable in the field, using the R value (R refers to the radius of curvature of the paraxial region, usually the R value in the lens database of optical software) to determine concavity or convexity. Taking the surface closest to the human eye as an example, when the R value is positive, it is determined to be convex, and when the R value is negative, it is determined to be concave; taking the surface closest to the display as an example, when the R value is positive, it is determined to be concave, and when the R value is negative, it is determined to be convex.

[0052] To address the problem of the inability to simultaneously achieve miniaturization and high image quality in existing VR optical systems, this invention provides a VR optical system.

[0053] Example 1

[0054] like Figures 1 to 20As shown, the VR optical system, from the human eye to the display, sequentially includes a first optical element group, a second optical element group, and a third optical element group. The first optical element group includes at least a first lens; the second optical element group includes at least a second lens; and the third optical element group includes a third lens, which has optical power. The first or second optical element group also includes a reflective polarizer and a quarter-retarder. Each lens has a surface near the human eye and a surface near the display. At least one surface of the first, second, and third lenses has a partially reflective layer. The effective focal lengths FG1 of the first optical element group, FG2 of the second optical element group, and FG3 of the third optical element group satisfy the following: 0 <FG1 / |FG2+FG3|<4.0。

[0055] By incorporating reflective polarizers, quarter-retarders, and a partial reflective layer into the VR optical system, the principle of polarization is used to fold the optical path, thereby increasing the optical path length while reducing the overall length of the VR optical system. This approach facilitates both high image quality and miniaturization. Placing the reflective polarizer and quarter-retarder within the first or second optical element group positions the optical path fold closer to the human eye, increasing the folding distance and effectively extending the optical path. This, in turn, enhances the imaging quality of the VR optical system while simultaneously shortening its length. Furthermore, limiting the focal lengths of the first, second, and third optical element groups rationally allocates the system's optical power, further improving the imaging quality and achieving a balance between miniaturization and high image quality.

[0056] Optionally, when the first optical element group includes a reflective polarizer and a quarter-retarder, the reflective polarizer and the quarter-retarder are bonded together, and the first lens is bonded to the reflective polarizer near the display side surface. Bonding the first lens, the reflective polarizer, and the quarter-retarder together helps to reduce the length of the VR optical system. The reflective polarizer and the quarter-retarder are conformal to the surface of the first lens near the display side, increasing the degree of freedom of the curved surface and thus improving the imaging quality of the VR optical system.

[0057] Optionally, when the second optical element group includes a reflective polarizer and a quarter-retarder, the reflective polarizer and the quarter-retarder are cemented together, and the second lens is cemented together with the quarter-retarder on the surface near the human eye. Cementing together the second lens, the reflective polarizer, and the quarter-retarder helps to reduce the length of the VR optical system. The reflective polarizer and the quarter-retarder are homomorphic to the surface near the human eye of the second lens, increasing the degree of freedom of the curved surface and thus improving the imaging quality of the VR optical system.

[0058] It should be noted that whether the reflective polarizer and the quarter-wave retarder are disposed on the first lens or the second lens, the reflective polarizer is closer to the human eye than the quarter-wave retarder.

[0059] In this embodiment, the central thickness CT2 of the second lens on the optical axis of the VR optical system and the central thickness CT3 of the third lens on the optical axis satisfy: 0.25 < CT2 / CT3 < 7.2. By controlling the ratio of the central thicknesses of the second lens and the third lens within a reasonable range, the optical powers of the second lens and the third lens can be controlled, so that the aberration of the second lens compensates for the aberration of the third lens, thereby reducing the aberration of the VR optical system and improving the imaging quality.

[0060] In this embodiment, the surface of the third lens close to the display is convex. By setting the surface of the third lens close to the display to be convex, the light is converged by the surface of the third lens close to the display, which is beneficial to reducing the screen size.

[0061] In this embodiment, the radius of curvature R22 of the surface of the second lens close to the display and the radius of curvature R31 of the surface of the third lens close to the human eye satisfy: 0.76 < R22 / R31 < 11.1. By controlling R22 / R31 within a reasonable range, it is beneficial to avoid interference between the second lens and the third lens, which is beneficial to the assembly stability of the second lens and the third lens, and ensures the assembly stability of the VR optical system.

[0062] In this embodiment, the effective focal length FG1 of the first optical element group and the effective focal length f of the VR optical system satisfy: 2.4 < FG1 / f < 16.4. By controlling FG1 / f within a reasonable range, it is beneficial to control the distribution of the optical power of the first lens in the optical system, so as to control the focal length of the first lens to compensate for the aberration generated by the second lens and the third lens, and improve the imaging quality of the VR optical system.

[0063] In this embodiment, the refractive indices of the first lens, the second lens and the third lens are greater than 1.5 and less than 1.7. By controlling the refractive indices of the three lenses to be within the range of low refractive indices, it is beneficial to the selection of low-stress materials, thereby reducing the influence of the birefringence of the materials on the polarization of the VR optical system.

[0064] In this embodiment, the distance T12 between the side surface of the first lens close to the display and the side surface of the second lens close to the human eye on the optical axis of the VR optical system, and the distance T23 between the side surface of the second lens close to the display and the side surface of the third lens close to the human eye on the optical axis satisfy: 1.0 < T23 / T12 < 3.8. By controlling T23 / T12 within a reasonable range, the air gaps in the VR optical system are evenly distributed, which is conducive to the abutment between the lenses, avoids the formation of large step structures, and is beneficial to increasing the assembly stability.

[0065] In this embodiment, the distance TD between the side surface of the first optical element group close to the human eye and the side surface of the third lens close to the display on the optical axis of the VR optical system, and the central thickness CT1 of the first lens on the optical axis satisfy: 4.6 < TD / CT1 < 7.2. By controlling TD / CT1 within a reasonable range, the proportion of the central thickness of the first lens in the total length of the entire optical system is reasonably controlled, the structural strength of the first lens is ensured, and it is beneficial to the stable abutment of the first lens.

[0066] In this embodiment, the radius of curvature R11 of the side surface of the first lens close to the human eye and the radius of curvature R22 of the side surface of the second lens close to the display satisfy: 0.6 < |R11 + R22| / (R11 - R22) < 5.8. By controlling |R11 + R22| / (R11 - R22) within a reasonable range, it is beneficial to control the shapes of the first lens and the second lens, is beneficial to film pasting on the first lens and the second lens, and at the same time is beneficial to reducing the reflection of light between the two lenses, thereby reducing the ghost image intensity of the VR optical system.

[0067] In this embodiment, the central thickness CT3 of the third lens on the optical axis of the VR optical system and the central thickness CTQ of the quarter wave plate on the optical axis satisfy: 10 ≤ CT3 / CTQ < 61.4. By controlling CT3 / CTQ within a reasonable range, it is beneficial to control the central thickness of the quarter wave plate, ensure the support strength of the quarter wave plate, and at the same time is beneficial to the adhesion between the quarter wave plate and the lens and the reflective polarizer.

[0068] In this embodiment, the first optical element group has a positive optical power. Setting the first optical element group to have a positive optical power is conducive to the convergence of light, which is beneficial to reducing the effective sizes of the second lens and the third lens, and is beneficial to the miniaturization of the VR optical system.

[0069] Embodiment 2

[0070] As Figures 1 to 20As shown, the VR optical system sequentially comprises a first optical element group, a second optical element group, and a third optical element group from the human eye to the display. The first optical element group includes at least a first lens; the second optical element group includes at least a second lens; and the third optical element group includes a third lens with optical power. The first or second optical element group also includes a reflective polarizer and a quarter-retarder. Each lens has a surface near the human eye and a surface near the display. At least one surface of the first, second, and third lenses has a partially reflective layer. The effective focal length FG1 of the first optical element group satisfies the relationship between the effective focal length f of the VR optical system and: 2.4 <FG1 / f<16.4。

[0071] By incorporating a reflective polarizer, a quarter-retarder, and a partial reflective layer into the VR optical system, the principle of polarization is used to fold the optical path, thereby increasing the optical path length while reducing the overall length of the VR optical system. This approach facilitates both high image quality and miniaturization. Placing the reflective polarizer and quarter-retarder in the first or second optical element group positions the optical path fold closer to the human eye, increasing the folding distance and effectively extending the optical path. This, in turn, improves the imaging quality of the VR optical system while simultaneously shortening its length. Furthermore, controlling the FG1 / f ratio within a reasonable range allows for better control of the first lens's power distribution within the optical system. This, in turn, controls the focal length of the first lens to compensate for aberrations generated by the second and third lenses, further enhancing the imaging quality of the VR optical system.

[0072] Optionally, when the first optical element group includes a reflective polarizer and a quarter-retarder, the reflective polarizer and the quarter-retarder are bonded together, and the first lens is bonded to the reflective polarizer near the display side surface. Bonding the first lens, the reflective polarizer, and the quarter-retarder together helps to reduce the length of the VR optical system. The reflective polarizer and the quarter-retarder are conformal to the surface of the first lens near the display side, increasing the degree of freedom of the curved surface and thus improving the imaging quality of the VR optical system.

[0073] Optionally, when the second optical element group includes a reflective polarizer and a quarter-retarder, the reflective polarizer and the quarter-retarder are cemented together, and the second lens is cemented together with the quarter-retarder on the surface near the human eye. Cementing together the second lens, the reflective polarizer, and the quarter-retarder helps to reduce the length of the VR optical system. The reflective polarizer and the quarter-retarder are homomorphic to the surface near the human eye of the second lens, increasing the degree of freedom of the curved surface and thus improving the imaging quality of the VR optical system.

[0074] It should be noted that whether the reflective polarizer and the quarter-wave retarder are disposed on the first lens or the second lens, the reflective polarizer is closer to the human eye than the quarter-wave retarder.

[0075] In this embodiment, the center thickness CT2 of the second lens on the optical axis of the VR optical system and the center thickness CT3 of the third lens on the optical axis satisfy: 0.25 < CT2 / CT3 < 7.2. By controlling the center thickness ratio of the second lens and the third lens within a reasonable range, the optical powers of the second lens and the third lens can be controlled, so that the aberration of the second lens and the aberration of the third lens compensate each other, thereby reducing the aberration of the VR optical system and improving the imaging quality.

[0076] In this embodiment, the surface of the third lens close to the display side is convex. By setting the surface of the third lens close to the display side as convex, the light is converged by the surface of the third lens close to the display side, which is beneficial to reducing the screen size.

[0077] In this embodiment, the radius of curvature R22 of the surface of the second lens close to the display side and the radius of curvature R31 of the surface of the third lens close to the human eye side satisfy: 0.76 < R22 / R31 < 11.1. By controlling R22 / R31 within a reasonable range, it is beneficial to avoid interference between the second lens and the third lens, which is beneficial to the assembly stability of the second lens and the third lens, and ensures the assembly stability of the VR optical system.

[0078] In this embodiment, the refractive indices of the first lens, the second lens and the third lens are greater than 1.5 and less than 1.7. By controlling the refractive indices of the three lenses so that the refractive indices of the lenses are within the range of low refractive indices, it is beneficial to the selection of low-stress materials, thereby reducing the influence of the birefringence of the materials on the polarization of the VR optical system.

[0079] In this embodiment, the distance T12 on the optical axis between the surface of the first lens close to the display side and the surface of the second lens close to the human eye side, and the distance T23 on the optical axis between the surface of the second lens close to the display side and the surface of the third lens close to the human eye side satisfy: 1.0 < T23 / T12 < 3.8. By controlling T23 / T12 within a reasonable range, the air gaps in the VR optical system are evenly distributed, which is beneficial to the bearing between the lenses, avoids the formation of a large-step structure, and is beneficial to increasing the assembly stability.

[0080] In this embodiment, the distance TD between the surface of the first optical element group close to the human eye side and the surface of the third lens close to the display side on the optical axis of the VR optical system, and the central thickness CT1 of the first lens on the optical axis satisfy: 4.6 < TD / CT1 < 7.2. By controlling TD / CT1 within a reasonable range, reasonably controlling the proportion of the central thickness of the first lens in the total length of the entire optical system, ensuring the structural strength of the first lens, and being beneficial to the stable bearing of the first lens.

[0081] In this embodiment, the radius of curvature R11 of the surface of the first lens close to the human eye side and the radius of curvature R22 of the surface of the second lens close to the display side satisfy: 0.6 < |R11 + R22| / (R11 - R22) < 5.8. By controlling |R11 + R22| / (R11 - R22) within a reasonable range, it is beneficial to control the shapes of the first lens and the second lens, beneficial to applying a film on the first lens and the second lens, and at the same time beneficial to reducing the reflection of light between the two lenses, thereby reducing the ghost image intensity of the VR optical system.

[0082] In this embodiment, the central thickness CT3 of the third lens on the optical axis of the VR optical system and the central thickness CTQ of the quarter-wave retarder on the optical axis satisfy: 10 ≤ CT3 / CTQ < 61.4. By controlling CT3 / CTQ within a reasonable range, it is beneficial to control the central thickness of the quarter-wave retarder, ensure the support strength of the quarter-wave retarder, and at the same time beneficial to the adhesion between the quarter-wave retarder and the lens and the reflective polarizer.

[0083] In this embodiment, the first optical element group has a positive optical power. Setting the first optical element group to have a positive optical power is beneficial to the convergence of light, thereby being beneficial to reducing the effective sizes of the second lens and the third lens and being beneficial to the miniaturization of the VR optical system.

[0084] The VR optical system in this application can adopt multiple lenses, such as the three lenses mentioned above. By reasonably distributing the optical powers, surface shapes, central thicknesses of each lens, and the on-axis distances between each lens, etc., the imaging quality of the VR optical system can be effectively improved and the volume of the VR optical system can be reduced.

[0085] In this application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. The characteristics of an aspherical lens are that the curvature changes continuously from the center of the lens to the periphery of the lens. Different from a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has better radius of curvature characteristics and has the advantages of improving distortion aberration and improving astigmatism aberration. After adopting an aspherical lens, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality.

[0086] However, those skilled in the art will understand that the number of lenses constituting the VR optical system can be changed without departing from the technical solutions claimed in this application to obtain the various results and advantages described in this specification. For example, although three lenses have been described as an example in the embodiments, the VR optical system is not limited to including three lenses. If necessary, the VR optical system may also include other numbers of lenses.

[0087] The following description, with reference to the accompanying drawings, further illustrates examples of specific surface features and parameters applicable to the VR optical system described above.

[0088] It should be noted that any of the examples one through five below are applicable to all embodiments of this application.

[0089] Example 1

[0090] like Figures 1 to 4 As shown, the VR optical system of Example 1 of this application is described. Figure 1 A schematic diagram of the VR optical system structure for Example 1 is shown.

[0091] like Figure 1 As shown, the VR optical system, from the human eye to the display, includes the human eye (STO), the first lens (E1), the reflective polarizer (PR), the quarter-retarder (QWP), the second lens (E2), the third lens (E3), and the image plane (IMG). The image plane (IMG) can be considered the display.

[0092] In this embodiment, the first optical element group includes a first lens E1, a reflective polarizer PR, and a quarter retarder QWP.

[0093] The first lens has a convex surface near the human eye and a flat surface near the display. The second lens has a convex surface near the human eye and a concave surface near the display. The third lens has a convex surface near both the human eye and display. The surface of the third lens near the display has a partial reflective layer.

[0094] Table 1 shows the basic structural parameters of the VR optical system in Example 1. The units for radius of curvature, thickness / distance and focal length are millimeters (mm). The arrangement of the surfaces is the order in which the light passes through. Refraction / reflection is the refraction or reflection of the light by the surface during this passage.

[0095]

[0096]

[0097] Table 1

[0098] In Example 1, the surface shape of the aspherical lenses in the first lens E1 to the third lens E3 can be defined using, but is not limited to, the following aspherical formula:

[0099]

[0100] Where x is the distance vector from the vertex of the aspherical surface at a height h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 2 below gives the higher-order coefficients A4, A6, A8, and A10 that can be used for the aspherical mirrors in Example 1.

[0101]

[0102] Table 2

[0103] Figure 2 The on-axis chromatic aberration curve of the VR optical system in Example 1 is shown, which represents the deflection of the focal point of light of different wavelengths after passing through the VR optical system. Figure 3 The astigmatism curves of the VR optical system in Example 1 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 4 The distortion curve of the VR optical system in Example 1 is shown, which represents the distortion magnitude corresponding to different field of view angles.

[0104] according to Figures 2 to 4 As can be seen, the VR optical system given in Example 1 can achieve good imaging quality.

[0105] Example 2

[0106] like Figures 5 to 8 As shown, the VR optical system of Example 2 of this application is described. Figure 5 A schematic diagram of the VR optical system structure for Example 2 is shown. For the sake of brevity, descriptions similar to those in Example 2 are omitted.

[0107] like Figure 5 As shown, the VR optical system, from the human eye to the display, includes the human eye STO, the first lens E1, the reflective polarizer PR, the quarter-retarder QWP, the second lens E2, the third lens E3, and the image plane IMG.

[0108] In this embodiment, the first optical element group includes a first lens E1, a reflective polarizer PR, and a quarter retarder QWP.

[0109] The first lens has a convex surface near the human eye and a flat surface near the display. The second lens has a convex surface near the human eye and a convex surface near the display. The third lens has a concave surface near the human eye and a convex surface near the display. The third lens has a partially reflective layer on its surface near the display.

[0110] Table 3 shows the basic structural parameters of the VR optical system in Example 2, where the units for radius of curvature, thickness / distance, and focal length are millimeters (mm).

[0111]

[0112] Table 3

[0113] Table 4 provides the coefficients of higher-order terms that can be used for each aspherical mirror in Example 5.

[0114]

[0115] Table 4

[0116] Figure 6 The on-axis chromatic aberration curve of the VR optical system in Example 2 is shown, which indicates the deflection of the focal point after light of different wavelengths passes through the VR optical system. Figure 7 The astigmatism curves of the VR optical system in Example 2 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 8 The distortion curve of the VR optical system in Example 2 is shown, which represents the distortion magnitude corresponding to different field of view angles.

[0117] according to Figures 6 to 8 As can be seen, the VR optical system given in Example 2 can achieve good imaging quality.

[0118] Example 3

[0119] like Figures 9 to 12 As shown, the VR optical system of Example 3 of this application is described. Figure 9 A schematic diagram of the VR optical system structure for Example 3 is shown. For the sake of brevity, descriptions similar to those in Example 3 are omitted.

[0120] like Figure 9 As shown, the VR optical system, from the human eye to the display, includes the human eye STO, the first lens E1, the reflective polarizer PR, the quarter-retarder QWP, the second lens E2, the third lens E3, and the image plane IMG.

[0121] In this embodiment, the second optical element group includes a reflective polarizer PR, a quarter-retarder QWP, and a second lens E2.

[0122] The first lens has a concave surface near the human eye and a convex surface near the display. The second lens has a flat surface near the human eye and a convex surface near the display. The third lens has a concave surface near the human eye and a convex surface near the display. The third lens has a partially reflective layer on its surface near the display.

[0123] Table 5 shows the basic structural parameters of the VR optical system in Example 3, where the units for radius of curvature, thickness / distance, and focal length are millimeters (mm).

[0124]

[0125] Table 5

[0126] Table 6 provides the coefficients of higher-order terms that can be used for each aspherical mirror in Example 2.

[0127]

[0128] Table 6

[0129] Figure 10 The on-axis chromatic aberration curve of the VR optical system in Example 3 is shown, which represents the deflection of the focal point after light of different wavelengths passes through the VR optical system. Figure 11 The astigmatism curves of the VR optical system in Example 3 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 12 The distortion curve of the VR optical system in Example 3 is shown, which represents the distortion magnitude corresponding to different field of view angles.

[0130] according to Figures 10 to 12 As can be seen, the VR optical system given in Example 3 can achieve good imaging quality.

[0131] Example 4

[0132] like Figures 13 to 16 As shown, the VR optical system of Example 4 of this application is described. Figure 13 A schematic diagram of the VR optical system structure for Example 4 is shown. For the sake of brevity, descriptions similar to those in Example 4 are omitted.

[0133] like Figure 13 As shown, the VR optical system, from the human eye to the display, includes the human eye STO, the first lens E1, the reflective polarizer PR, the quarter-retarder QWP, the second lens E2, the third lens E3, and the image plane IMG.

[0134] In this embodiment, the second optical element group includes a reflective polarizer PR, a quarter-retarder QWP, and a second lens E2.

[0135] The first lens has a concave surface near the human eye and a convex surface near the display. The second lens has a flat surface near the human eye and a concave surface near the display. The third lens has a convex surface near the human eye and a convex surface near the display. The third lens has a partially reflective layer on its surface near the display.

[0136] Table 7 shows the basic structural parameters of the VR optical system in Example 4, where the units for radius of curvature, thickness / distance, and focal length are millimeters (mm).

[0137]

[0138]

[0139] Table 7

[0140] Table 8 gives the coefficients of higher-order terms that can be used for each aspherical mirror in Example 2.

[0141]

[0142] Table 8

[0143] Figure 14 The on-axis chromatic aberration curve of the VR optical system in Example 4 is shown, which represents the deflection of the focal point after light of different wavelengths passes through the VR optical system. Figure 15 The astigmatism curves of the VR optical system in Example 4 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 16 The distortion curve of the VR optical system in Example 4 is shown, which represents the distortion magnitude corresponding to different field of view angles.

[0144] according to Figures 14 to 16 As can be seen, the VR optical system given in Example 4 can achieve good imaging quality.

[0145] Example 5

[0146] like Figures 17 to 20 As shown, the VR optical system of Example 5 of this application is described. Figure 17 A schematic diagram of the VR optical system structure for Example 5 is shown. For the sake of brevity, descriptions similar to those in Example 5 are omitted.

[0147] like Figure 17 As shown, the VR optical system consists of the human eye (STO), first lens (E1), reflective polarizer (PR), quarter-retarder (QWP), second lens (E2), third lens (E3), and image plane (IMG) in sequence from the human eye to the display.

[0148] In this embodiment, the second optical element group includes a reflective polarizer PR, a quarter-retarder QWP, and a second lens E2.

[0149] The first lens has a concave surface near the human eye and a convex surface near the display. The second lens has a flat surface near the human eye and a convex surface near the display. The third lens has a concave surface near the human eye and a convex surface near the display. The third lens has a partially reflective layer on its surface near the display.

[0150] Table 9 shows the basic structural parameters of the VR optical system in Example 5, where the units for radius of curvature, thickness / distance, and focal length are millimeters (mm).

[0151]

[0152] Table 9

[0153] Table 10 gives the coefficients of higher-order terms that can be used for each aspherical mirror in Example 3.

[0154]

[0155] Table 10

[0156] Figure 18 The on-axis chromatic aberration curve of the VR optical system in Example 5 is shown, which represents the deflection of the focal point of light of different wavelengths after passing through the VR optical system. Figure 19 The astigmatism curves of the VR optical system in Example 5 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 20 The distortion curve of the VR optical system in Example 5 is shown, which represents the distortion magnitude corresponding to different field of view angles.

[0157] according to Figures 18 to 20 As can be seen, the VR optical system given in Example 5 can achieve good imaging quality.

[0158] Examples 1 and 2 illustrate the trajectory of light emitted from the image plane IMG. The light emitted from the image plane IMG passes sequentially through the third lens near the display side surface (surface 18), the third lens near the eye side surface (surface 17), the second lens near the display side surface (surface 16), and the second lens near the eye side surface (surface 15), before incident on the quarter-retarder near the display side surface (surface 14). The quarter-retarder converts the light into a first polarization state. This first polarization state light then strikes the reflective polarizer near the display side surface (surface 13, also a quarter-retarder near the eye side surface) and is reflected to form the first reflected light. This first reflected light then strikes the quarter-retarder near the display side surface (surface 12), where the quarter-retarder QWP converts the first reflected light into a second polarization state. This second polarization state light then sequentially passes through the second lens near the eye side surface (surface 11). The second lens near the display side surface (surface 10) and the third lens near the human eye side surface (surface 9) are reflected by the third lens near the display side surface (surface 8, the part of the reflective layer near the third lens near the display side surface) to form a second reflected light. The second reflected light passes sequentially through the third lens near the human eye side surface (surface 7), the second lens near the display side surface (surface 6), and the second lens near the human eye side surface (surface 5) before being incident on the quarter-retarder near the display side surface (surface 4). The quarter-retarder QWP converts the second magnetically reflected light into light of the third polarization state. The light of the third polarization state is incident on the reflective polarizer near the display side surface (surface 3) and transmitted by the reflective polarizer near the display side surface (surface 3). The transmitted light passes sequentially through the first lens near the display side surface (surface 2) and the first lens near the human eye side surface (surface 1) before being incident on the human eye STO.

[0159] The light paths in Examples 3 to 5 are similar to those in Examples 1 and 2, and will not be described in detail here.

[0160] It should be noted that during the process of light from the first polarization state becoming light from the third polarization state, it passes through two quarter-retarder plates, which makes the polarization direction of the light from the first polarization state perpendicular to the polarization direction of the light from the third polarization state. Therefore, the reflective polarizing element reflects the light from the first polarization state and transmits the light from the third polarization state.

[0161] In summary, Examples 1 through 5 satisfy the relationships shown in Table 6.

[0162] Expressions / Examples Example 1 Example 2 Example 3 Example 4 Example 5 FG1 / (FG2+FG3) 1.526 3.963 0.692 0.704 0.006 CT2 / CT3 0.2504 5.695 7.160 0.308 0.437 R22 / R31 1.238 1.095 0.771 0.864 11.030 FG1 / f 9.454 16.377 5.105 2.413 2.407 T23 / T12 1.047 1.109 1.336 3.740 2.480 TD / CT1 7.133 7.164 6.856 4.733 4.686 |R11+R22| / (R11-R22) 5.746 0.647 1.235 0.737 1.310 CT3 / CTQ 52.500 10.000 10.000 61.380 57.750

[0163] Table 6

[0164] Table 7 provides some parameters of the VR optical systems in Examples 1 to 5.

[0165]

[0166]

[0167] Table 7

[0168] This application also provides an imaging device, whose electronic photosensitive element can be a photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device can be a stand-alone imaging device such as a digital camera, or an imaging module integrated into a mobile electronic device such as a mobile phone. The imaging device is equipped with the VR optical system described above.

[0169] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0170] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0171] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0172] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A VR optical system, characterized in that, The VR optical system has three lenses with optical power, and sequentially includes a first optical element group, a second optical element group, and a third optical element group from the human eye to the display. The first optical element group includes at least a first lens having optical power, and the first optical element group has positive optical power; The second optical element group includes at least a second lens having optical power; The third optical element group includes a third lens, which has optical power and the surface of the third lens near the display side is convex. The first optical element group or the second optical element group further includes a reflective polarizer and a quarter retarder; The lens has a surface near the human eye and a surface near the display, and at least one of the first lens, the second lens and the third lens has a partially reflective layer on its surface, and the third lens has the partially reflective layer on its surface near the display. The effective focal lengths FG1 of the first optical element group, FG2 of the second optical element group, and FG3 of the third optical element group satisfy the following: 0.006≤FG1 / |FG2+FG3|≤3.963; The distance T12 between the first lens near the display side surface and the second lens near the human eye side surface on the optical axis of the VR optical system, and the distance T23 between the second lens near the display side surface and the third lens near the human eye side surface on the optical axis, satisfy the following condition: 1.047≤T23 / T12≤3.740; The distance TD between the surface of the first optical element group near the human eye and the surface of the third lens near the display on the optical axis of the VR optical system, and the center thickness CT1 of the first lens on the optical axis, satisfy the following: 4.686≤TD / CT1≤7.164; When the first optical element group includes the reflective polarizer and the quarter-retarder, the reflective polarizer and the quarter-retarder are bonded together, and the first lens is bonded together with the reflective polarizer on the surface near the display; or when the second optical element group includes the reflective polarizer and the quarter-retarder, the reflective polarizer and the quarter-retarder are bonded together, and the second lens is bonded together with the quarter-retarder on the surface near the human eye.

2. The VR optical system according to claim 1, characterized in that, The center thickness CT2 of the second lens on the optical axis of the VR optical system and the center thickness CT3 of the third lens on the optical axis satisfy the following condition: 0.2504≤CT2 / CT3≤7.

160.

3. The VR optical system according to claim 1, characterized in that, The radius of curvature R22 of the second lens near the display side surface and the radius of curvature R31 of the third lens near the human eye side surface satisfy the following condition: 0.771≤R22 / R31≤11.

030.

4. The VR optical system according to claim 1, characterized in that, The effective focal length FG1 of the first optical element group and the effective focal length f of the VR optical system satisfy the following condition: 2.407≤FG1 / f≤16.

377.

5. The VR optical system according to claim 1, characterized in that, The refractive indices of the first lens, the second lens, and the third lens are greater than 1.5 and less than 1.

7.

6. The VR optical system according to any one of claims 1 to 5, characterized in that, The radius of curvature R11 of the first lens near the human eye side and the radius of curvature R22 of the second lens near the display side satisfy the following condition: 0.647≤|R11+R22| / (R11-R22)≤5.

746.

7. The VR optical system according to any one of claims 1 to 5, characterized in that, The center thickness CT3 of the third lens on the optical axis of the VR optical system and the center thickness CTQ of the quarter-retarder on the optical axis satisfy the following condition: 10 ≤ CT3 / CTQ ≤ 61.380.

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