Optical system and VR device

Abstract

The utility model discloses an optical system and VR equipment comprising the optical system, the optical system comprises a lens barrel and a lens assembly arranged in the lens barrel, and the lens assembly comprises a first lens, a second lens and a third lens in sequence from a first side to a second side along an optical axis; the lens barrel is provided with a front end face facing the first side and a rear end face facing the second side. The second side surface of the second lens is a plane; the first side surface of the third lens is a plane, and the second side surface is a convex surface; the air interval T23 of the second lens and the third lens on the optical axis meets the condition that T23 is greater than or equal to 0 mm and less than or equal to 0.02 mm; and an air interval T12 between the first lens and the second lens on the optical axis, an air interval T23 between the second lens and the third lens on the optical axis, and the maximum height L of the lens barrel in the optical axis direction satisfy the following formula: 11.0 < L / (T12 + T23) < 24.0. The optical system at least has the advantages of being low in forming difficulty, small in size and high in imaging quality, and good user experience can be achieved when the optical system is matched with VR equipment.

Description

Technical Field

[0001] The present application relates to the field of optical elements, and more specifically, to an optical system and a VR device including the optical system. Background Art

[0002] In recent years, with the concept of "metaverse" being proposed, people's entertainment methods have become increasingly diverse, among which human-computer interactive devices such as AR / VR are becoming more and more popular. However, the biggest disadvantages of VR lenses at present are their large size, heaviness and dizziness, which cannot meet people's needs well. In order to better eliminate the above-mentioned defects of VR lenses and improve the user experience, the miniaturization, lightweight and imaging quality of the lenses have become the most important factors to improve the consumer experience. Therefore, how to make the structure of VR lenses more compact and lightweight, optimize the structural design in eliminating chromatic aberration, phase difference and various stray light problems, and then improve the imaging quality and processability of the lenses, is one of the hot topics studied by researchers in this field. Utility Model Content

[0003] The first aspect of the present application provides an optical system, which includes: a lens barrel and a lens assembly arranged in the lens barrel, wherein the lens assembly includes: a first lens, a second lens and a third lens in sequence from the first side to the second side along the optical axis; the lens barrel has a front end face facing the first side and a rear end face facing the second side; the second side surface of the second lens is a plane; the first side surface of the third lens is a plane, and the second side surface is a convex surface; the air interval T23 between the second lens and the third lens on the optical axis satisfies: 0mm≤T23≤0.02mm; and the air interval T12 between the first lens and the second lens on the optical axis, the air interval T23 between the second lens and the third lens on the optical axis and the maximum height L of the lens barrel along the optical axis direction satisfy: 11.0<L / (T12+T23)<24.0.

[0004] In one embodiment, the optical system also includes at least one spacer disposed in the lens barrel; the at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein an outer diameter D1m of the second side surface of the first spacer and an inner diameter d1m of the second side surface of the first spacer satisfy: 4.5<d1m / (D1m-d1m)<17.5.

[0005] In one embodiment, the optical system also includes at least one spacer disposed in the lens barrel; the at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein the maximum height L of the lens barrel along the optical axis, the distance EP01 between the front end face of the lens barrel and the first side face of the first spacer along the optical axis, the maximum thickness CP1 of the first spacer along the optical axis, the center thickness CT2 of the second lens on the optical axis, and the center thickness CT3 of the third lens on the optical axis satisfy: 0.7<(L-EP01-CP1) / (CT2+CT3)<1.6.

[0006] In one embodiment, the optical system also includes at least one spacer disposed in the lens barrel; the at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein the inner diameter d1s of the first side surface of the first spacer, the refractive index N1 of the first lens and the center thickness CT1 of the first lens on the optical axis satisfy: 3.5<d1s / (N1×CT1)<15.5.

[0007] In one embodiment, the optical system also includes at least one spacer disposed in the lens barrel; the at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein the outer diameter D1s of the first side surface of the first spacer, the inner diameter d1s of the first side surface of the first spacer and the center thickness CT1 of the first lens on the optical axis satisfy: 0.5<(D1s-d1s) / CT1<1.6.

[0008] In one embodiment, the optical system also includes at least one spacer disposed in the lens barrel; the at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein the outer diameter D1m of the second side surface of the first spacer, the refractive index N2 of the second lens, the refractive index N3 of the third lens, the center thickness CT2 of the second lens on the optical axis, and the center thickness CT3 of the third lens on the optical axis satisfy: 2.0<D1m / (N2×CT2+N3×CT3)<4.5.

[0009] In one embodiment, the optical system also includes at least one spacer disposed in the lens barrel; the at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein the distance EP01 between the front end face of the lens barrel and the first side face of the first spacer along the optical axis direction and the center thickness CT1 of the first lens on the optical axis satisfy: 0.1<EP01 / CT1<1.1.

[0010] In one embodiment, the optical system also includes at least one spacer disposed in the lens barrel; the at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein the maximum thickness CP1 of the first spacer along the optical axis and the air gap T12 between the first lens and the second lens on the optical axis satisfy: 0≤CP1 / T12<4.0.

[0011] In one embodiment, the optical system also includes at least one spacer disposed in the lens barrel; the at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein the inner diameter d0s of the front end surface of the lens barrel and the inner diameter d1s of the first side surface of the first spacer satisfy: 0.5<d0s / d1s<1.0.

[0012] In one embodiment, the axial distance TD from the first side surface of the first lens to the second side surface of the third lens, the outer diameter D0m of the rear end surface of the lens barrel and the outer diameter D0s of the front end surface of the lens barrel satisfy: 0.5<TD / (D0m-D0s)<3.5.

[0013] In one embodiment, the at least one spacer further includes: a second spacer disposed between the lens barrel and the first side surface of the first lens.

[0014] In one embodiment, the outer diameter D0s of the front end surface of the lens barrel, the inner diameter d0s of the front end surface of the lens barrel, the outer diameter D01s of the first side surface of the second spacer and the inner diameter d01s of the first side surface of the second spacer satisfy: 1.3<(D0s-d0s) / (D01s-d01s)<2.2.

[0015] In one embodiment, the center thickness CT1 of the first lens on the optical axis and the distance EP001 between the front end surface of the lens barrel and the first side surface of the second spacer along the optical axis direction satisfy: 1.0<CT1 / EP001<5.0.

[0016] In one embodiment, the optical system further includes a reflective component, which includes a reflective polarizing element, a quarter wave plate and a partial reflective layer in sequence from the first side to the second side along the optical axis, wherein the reflective polarizing element and the quarter wave plate are arranged on at least one of the first side surface and the second side surface of the first lens and the second lens, and the partial reflective layer is arranged on the first side surface or the second side surface of the third lens.

[0017] The second aspect of the present application also provides an optical system, which includes: a lens barrel and a lens assembly and at least one spacer arranged in the lens barrel, the at least one spacer including a first spacer arranged between the first lens and the second lens and in contact with the first lens; wherein the lens assembly includes: a first lens, a second lens and a third lens in sequence from the first side to the second side along the optical axis; the lens barrel has a front end face facing the first side and a rear end face facing the second side; the second side surface of the second lens is a plane; the first side surface of the third lens is a plane, and the second side surface is a convex surface; the air interval T23 between the second lens and the third lens on the optical axis satisfies: 0mm≤T23≤0.02mm; and the maximum height L of the lens barrel along the optical axis, the distance EP01 between the front end surface of the lens barrel and the first side surface of the first spacer along the optical axis, the maximum thickness CP1 of the first spacer along the optical axis, the center thickness CT2 of the second lens on the optical axis and the center thickness CT3 of the third lens on the optical axis satisfy: 0.7<(L-EP01-CP1) / (CT2+CT3)<1.6.

[0018] The third aspect of the present application also provides an optical system, which includes: a lens barrel and a lens assembly and at least one spacer arranged in the lens barrel, the at least one spacer including a first spacer arranged between the first lens and the second lens and in contact with the first lens; wherein the lens assembly includes, in sequence from the first side to the second side along the optical axis: a first lens, a second lens and a third lens; the lens barrel has a front end face facing the first side and a rear end face facing the second side; the second side surface of the second lens is a plane; the first side surface of the third lens is a plane, and the second side surface is a convex surface; the air gap T23 between the second lens and the third lens on the optical axis satisfies: 0mm≤T23≤0.02mm; and the outer diameter D1s of the first side surface of the first spacer, the inner diameter d1s of the first side surface of the first spacer and the center thickness CT1 of the first lens on the optical axis satisfy: 0.5<(D1s-d1s) / CT1<1.6.

[0019] The fourth aspect of the present application also provides an optical system, which includes: a lens barrel and a lens assembly and at least one spacer arranged in the lens barrel, the at least one spacer including a first spacer arranged between the first lens and the second lens and in contact with the first lens; wherein the lens assembly includes: a first lens, a second lens and a third lens in sequence from the first side to the second side along the optical axis; the lens barrel has a front end face facing the first side and a rear end face facing the second side; the second side surface of the second lens is a plane; the first side surface of the third lens is a plane, and the second side surface is a convex surface; the air gap T23 between the second lens and the third lens on the optical axis satisfies: 0mm≤T23≤0.02mm; and the outer diameter D1m of the second side surface of the first spacer, the refractive index N2 of the second lens, the refractive index N3 of the third lens, the center thickness CT2 of the second lens on the optical axis and the center thickness CT3 of the third lens on the optical axis satisfy: 2.0<D1m / (N2×CT2+N3×CT3)<4.5.

[0020] The fifth aspect of the present application also provides a VR device, characterized in that it includes: the optical system provided by any of the above-mentioned embodiments; and a transmitting unit, used to transmit a light signal, the light signal including image information; the optical system is arranged in the light emitting direction of the transmitting unit, and the third lens is arranged closer to the transmitting unit than the first lens, and the optical system is used to modulate the light signal emitted by the transmitting unit and transmit it to the human eye.

[0021] The optical system and VR device provided by the present application use three lenses, and have the characteristics of good projection quality, short total length and good processability. The optical system provided by the present application controls the surface shape of the second lens and the third lens, so that the second side surface of the second lens and the first side surface of the third lens are both planes, and the second lens and the third lens are glued together, and meet 0mm≤T23≤0.02mm and 11.0<L / (T12+T23)<24.0, which effectively reduces the difficulty of lens molding, and does not increase the total length, weight and stray light risk of the lens. At the same time, by limiting the air interval between the first lens and the second lens and the maximum height of the lens barrel, the field curvature of the system is constrained within a certain range, and finally the lens as a whole obtains a better imaging effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, purposes and advantages of the present application will become more apparent through the following detailed description of non-limiting embodiments in conjunction with the accompanying drawings. In the accompanying drawings:

[0023] Figure 1 A schematic diagram showing some parameters of an optical system according to the present application;

[0024] Figure 2 A structural schematic diagram of a VR device according to the present application is shown;

[0025] Figure 3A and Figure 3B The schematic diagrams of the structures of the optical systems according to Embodiment 1 and Embodiment 2 of the present application are shown respectively;

[0026] FIG. 4A to FIG. 4C The axial chromatic aberration curve, the astigmatism curve and the distortion curve of the optical system according to Embodiment 1 and Embodiment 2 of the present application are respectively shown;

[0027] Figure 5A and Figure 5B The schematic diagrams of the structures of the optical systems according to Embodiment 3 and Embodiment 4 of the present application are shown respectively;

[0028] FIG. 6A to FIG. 6C The axial chromatic aberration curve, the astigmatism curve and the distortion curve of the optical system according to Embodiment 3 and Embodiment 4 of the present application are respectively shown;

[0029] Fig. 7A and Figure 7B The schematic diagrams of the structures of the optical systems according to Embodiment 5 and Embodiment 6 of the present application are shown respectively;

[0030] FIG. 8A to FIG. 8C The axial chromatic aberration curve, the astigmatism curve and the distortion curve of the optical system according to Embodiment 5 and Embodiment 6 of the present application are respectively shown;

[0031] Fig.9A and Fig. 9B Schematic diagrams of the structures of optical systems according to Embodiment 7 and Embodiment 8 of the present application are respectively shown; and

[0032] FIG. 10A to FIG. 10C The axial chromatic aberration curve, the astigmatism curve and the distortion curve of the optical system according to Embodiment 7 and Embodiment 8 of the present application are respectively shown;

[0033] Fig.11 A cross-sectional view of a lens barrel of an optical system according to the present application along the plane where the optical axis is located is shown. DETAILED DESCRIPTION

[0034] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0035] It should be noted that in this specification, the expressions of first, second, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens, and the second lens may also be referred to as the first lens.

[0036] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0037] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the convex position 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 concave position is not defined, it means that the lens surface is concave at least in the paraxial region.

[0038] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0039] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0040] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] The features, principles and other aspects of the present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0042] The optical system according to the exemplary embodiment of the present application includes: a lens barrel and a lens assembly arranged in the lens barrel. The lens assembly may include three lenses with optical power, namely a first lens, a second lens and a third lens. The three lenses are arranged in sequence from the first side to the second side along the optical axis. The lens barrel has a front end surface facing the first side and a rear end surface facing the second side. Exemplarily, the lens barrel can be an integrated lens barrel.

[0043] In an exemplary embodiment, the optical system provided in the present application can be applied to, for example, a VR device, the first side can be, for example, a human eye side, and the second side can be, for example, a display side or an image source side.

[0044] The optical system according to the exemplary embodiment of the present application may also include at least one spacer, which may be arranged between any two adjacent lenses, and may also be arranged between the lens barrel and the first side of the first lens, or between the lens barrel and the second side of the third lens. Exemplarily, at least one spacer may include a first spacer arranged between the first lens and the second lens and in contact with the first lens. Exemplarily, at least one spacer may include a second spacer arranged between the lens barrel and the first side of the first lens.

[0045] It should be understood that the present application does not specifically limit the number of spacers, and any number of spacers may be included between any two lenses, and the entire optical system may also include any number of spacers. Optionally, as required, at least one spacer may also include a third spacer disposed between the second lens and the third lens and in contact with the second lens. Optionally, as required, at least one spacer may also include a fourth spacer disposed between the second side of the third lens and the lens barrel. The spacer helps the optical system intercept excess refractive and reflective light paths and reduce the generation of stray light and ghosting. Auxiliary support may be added between the spacer and the lens barrel, which is beneficial to improving the poor assembly stability and low performance yield caused by the large step difference between the lenses. By reasonably setting the number, thickness, inner diameter and outer diameter of the spacer, it is beneficial to improve the assembly of the optical system, to block stray light, and to improve the projection quality of the optical system.

[0046] The optical system according to the exemplary embodiment of the present application may also include a reflective component, which includes at least one reflective element, and the reflective element may be, for example, a reflective polarizing element, a quarter wave plate, and a partial reflective layer. The optical system can reflect light of a certain polarization direction and transmit light orthogonal to the polarization direction by setting a reflective polarizing element; the optical system can change the polarization state of light by setting a quarter wave plate; the partial reflective layer has a semi-transmissive and semi-reflective function, and the optical system can achieve reflection and transmission by setting a partial reflective layer.

[0047] The present application can change the polarization state of polarized light by attaching a reflective polarizer and a quarter-wave plate on the surface of the first lens or the second lens, so that the light is reflected when it passes through the reflective polarizer for the first time and is transmitted when it passes through the reflective polarizer for the second time; at least one of the first side surface and the second side surface of the third lens is provided with a partial reflective layer, and the reflective polarizer, the quarter-wave plate and the partial reflective layer can refract the light path of the optical system, which is beneficial to shortening the length of the optical system.

[0048] In an exemplary embodiment, the reflective polarizing element may be disposed on the first side or the second side of the first lens, and the reflective polarizing element may also be disposed on the first side of the second lens; the quarter-wave plate may be disposed on the first side or the second side of the second lens, and the partial reflective layer may be placed on the first side or the second side of the third lens.

[0049] In an exemplary embodiment, the reflective polarizing element and the quarter wave plate may be attached together to the first side surface of the second lens.

[0050] The optical system according to the exemplary embodiment of the present application includes: a lens barrel and a lens assembly arranged in the lens barrel. The lens assembly may include three lenses with optical power, namely a first lens, a second lens and a third lens. The three lenses are arranged in sequence from the first side to the second side along the optical axis. The lens barrel has a front end face facing the first side and a rear end face facing the second side. Among them, the second side surface of the second lens is a plane; the first side surface of the third lens is a plane, and the second side surface is a convex surface. The optical system can satisfy 0mm≤T23≤0.02mm and 11.0<L / (T12+T23)<24.0, wherein T23 is the air interval between the second lens and the third lens on the optical axis, T12 is the air interval between the first lens and the second lens on the optical axis, and L is the maximum height of the lens barrel along the optical axis. The present application controls the surface shape of the second lens and the third lens so that the second side surface of the second lens and the first side surface of the third lens are both planes, and the second lens and the third lens can be glued together, which not only splits the optically designed convex-concave lens into convex-flat and plano-concave lenses, effectively reducing the difficulty of lens molding, but also does not increase the total length, weight and stray light risk of the lens. At the same time, by limiting the air gap between the first lens and the second lens and the maximum height of the lens barrel, the field curvature of the system is constrained within a certain range, and finally the lens as a whole obtains a better imaging effect.

[0051] Figure 1 A schematic diagram showing some parameters of an optical system according to the present application is shown. It should be understood by those skilled in the art that some parameters of lenses commonly used in the art (such as the center thickness CT2 of the second lens on the optical axis) are not shown in FIG. Figure 1 It is shown in Figure 1Only some parameters of the lens barrel and the spacer of an optical system of the present application are shown as examples to facilitate a better understanding of the present invention. Figure 1 As shown, L represents the maximum height of the lens barrel along the optical axis, EP01 represents the distance between the front end face of the lens barrel and the first side face of the first spacer along the optical axis, EP001 represents the distance between the front end face of the lens barrel and the first side face of the second spacer along the optical axis, CP1 represents the maximum thickness of the first spacer along the optical axis, D0s represents the outer diameter of the front end face of the lens barrel, d0s represents the inner diameter of the front end face of the lens barrel, D1s represents the outer diameter of the first side face of the first spacer, d1s represents the inner diameter of the first side face of the first spacer, D01s represents the outer diameter of the first side face of the second spacer, d01s represents the inner diameter of the first side face of the second spacer, D1m represents the outer diameter of the second side face of the first spacer, d1m represents the inner diameter of the second side face of the first spacer, and D0m represents the outer diameter of the rear end face of the lens barrel.

[0052] In an exemplary embodiment, the optical system of the present application may satisfy: 4.5<d1m / (D1m-d1m)<17.5, wherein D1m is the outer diameter of the second side of the first spacer, and d1m is the inner diameter of the second side of the first spacer. Satisfying 4.5<d1m / (D1m-d1m)<17.5 is conducive to ensuring the structural support of the first spacer while preventing the first spacer from interfering with the assembly of the first lens and the second lens, and is also conducive to balancing the processability of the first spacer and the compactness required for the overall structure.

[0053] In an exemplary embodiment, the optical system of the present application may satisfy: 0.7<(L-EP01-CP1) / (CT2+CT3)<1.6, wherein L is the maximum height of the lens barrel along the optical axis, EP01 is the distance between the front end surface of the lens barrel and the first side surface of the first spacer along the optical axis, CP1 is the maximum thickness of the first spacer along the optical axis, CT2 is the center thickness of the second lens on the optical axis, and CT3 is the center thickness of the third lens on the optical axis. Satisfying 0.7<(L-EP01-CP1) / (CT2+CT3)<1.6 can prevent the lens barrel from being too long, affecting the length of the whole machine, and can reasonably distribute the thickness of the first spacer, the second lens, and the third lens to avoid being too small, and ensure the processability of the first spacer, the second lens, and the third lens under the premise of ensuring the stability of the system assembly.

[0054] In an exemplary embodiment, the optical system of the present application may satisfy: 3.5<d1s / (N1×CT1)<15.5, wherein d1s is the inner diameter of the first side surface of the first spacer, N1 is the refractive index of the first lens, and CT1 is the center thickness of the first lens on the optical axis. Satisfying 3.5<d1s / (N1×CT1)<15.5 can control the shape of the first lens, which is beneficial to its processability, and at the same time ensure the stability of the first lens and the first spacer, which is beneficial to the lens assembly and reliability.

[0055] In an exemplary embodiment, the optical system of the present application may satisfy: 0.5<(D1s-d1s) / CT1<1.6, wherein D1s is the outer diameter of the first side surface of the first spacer, d1s is the inner diameter of the first side surface of the first spacer, and CT1 is the center thickness of the first lens on the optical axis. Satisfying 0.5<(D1s-d1s) / CT1<1.6 can control the shape of the first lens, which is beneficial to its processability, and at the same time ensure the stability of the first lens and the first spacer, which is beneficial to the lens assembly and reliability.

[0056] In an exemplary embodiment, the optical system of the present application may satisfy: 2.0<D1m / (N2×CT2+N3×CT3)<4.5, wherein D1m is the outer diameter of the second side surface of the first spacer, N2 is the refractive index of the second lens, N3 is the refractive index of the third lens, CT2 is the center thickness of the second lens on the optical axis, and CT3 is the center thickness of the third lens on the optical axis. Satisfying 2.0<D1m / (N2×CT2+N3×CT3)<4.5 can control the appearance of the second lens and the third lens, which is beneficial to their processability, and at the same time ensures the stability of the second lens, the third lens and the second spacer, which is beneficial to the lens assembly and reliability.

[0057] In an exemplary embodiment, the optical system of the present application may satisfy: 0.1<EP01 / CT1<1.1, wherein EP01 is the distance between the front end face of the lens barrel and the first side face of the first spacer along the optical axis, and CT1 is the center thickness of the first lens on the optical axis. Satisfying 0.1<EP01 / CT1<1.1 can reasonably distribute the thickness of the front end face of the first lens and the lens barrel, and ensure the processability of the two while ensuring the assembly of the system.

[0058] In an exemplary embodiment, the optical system of the present application may satisfy: 0≤CP1 / T12<4.0, where CP1 is the maximum thickness of the first spacer along the optical axis, and T12 is the air gap between the first lens and the second lens on the optical axis. When 0≤CP1 / T12<4.0 is satisfied, the air gap between the first lens and the second lens on the optical axis and the thickness of the first spacer can be reasonably allocated, and the first lens and the second lens are prevented from being too convex or too concave, thereby reducing the difficulty of processing the first lens and the second lens.

[0059] In an exemplary embodiment, the optical system of the present application may satisfy: 0.5<d0s / d1s<1.0, wherein d0s is the inner diameter of the front end surface of the lens barrel, and d1s is the inner diameter of the first side surface of the first spacer. Fig.11 It is a cross-sectional view of the lens barrel along the plane where the optical axis is located. The inner diameter of the lens barrel P0 gradually increases from the front end to the rear end. The line connecting the inner wall of the front end to the rear end of the lens barrel P0 on both sides of the optical axis constitutes the opening angle The optical system of the present application satisfies 0.5<d0s / d1s<1.0, which can limit the structural direction of the inner wall of the lens barrel, prevent the lens barrel from having an angle that is too large and not machinable, and on the other hand prevent the lens barrel from having an angle that is too small, which is not conducive to the lens shape design.

[0060] In an exemplary embodiment, the optical system of the present application may satisfy: 0.5<TD / (D0m-D0s)<3.5, wherein TD is the on-axis distance from the first side surface of the first lens to the second side surface of the third lens, D0m is the outer diameter of the rear end surface of the lens barrel, and D0s is the outer diameter of the front end surface of the lens barrel. Satisfying 0.5<TD / (D0m-D0s)<3.5 can limit the direction of the outer shape of the lens barrel structure, on the one hand, preventing the outer diameter of the lens barrel from being too large, affecting the assembly space of the overall design; on the other hand, preventing the outer diameter of the lens barrel from being too small, which makes processing and molding too difficult.

[0061] In an exemplary embodiment, the optical system of the present application further includes a second spacer disposed between the lens barrel and the first side surface of the first lens. Since the first lens and the lens barrel are relatively large in size, the thickness tolerance range thereof is relatively large, which will affect the distance from the first lens to the display screen. By arranging spacers of different thickness specifications between the lens barrel and the first side surface of the first lens, it is possible to ensure that the distance from the first lens to the display screen does not have a large deviation, thereby ensuring the lens performance.

[0062] In an exemplary embodiment, the optical system of the present application may satisfy: 1.3<(D0s-d0s) / (D01s-d01s)<2.2, wherein D0s is the outer diameter of the front end face of the lens barrel, d0s is the inner diameter of the front end face of the lens barrel, D01s is the outer diameter of the first side face of the second spacer, and d01s is the inner diameter of the first side face of the second spacer. Satisfying 1.3<(D0s-d0s) / (D01s-d01s)<2.2 can limit the shape of the front end face of the lens barrel, on the one hand, preventing the front end face of the lens barrel from bearing too little to affect the lens assembly, and on the other hand, preventing the front end face of the lens barrel from being too large and occupying too much space in the whole machine.

[0063] In an exemplary embodiment, the optical system of the present application may satisfy: 1.0<CT1 / EP001<5.0, wherein CT1 is the center thickness of the first lens on the optical axis, and EP001 is the distance between the front end face of the lens barrel and the first side face of the second spacer along the optical axis. Satisfying 1.0<CT1 / EP001<5.0 can reasonably distribute the thickness of the front end face of the first lens and the lens barrel, and ensure the processability of the two while ensuring the assembly of the system.

[0064] In an exemplary embodiment, the optical system of the present application may include at least one aperture. The aperture may constrain the optical path and control the light intensity. The aperture may be set at an appropriate position of the optical system, for example, the aperture may be located at the first side of the first lens.

[0065] The optical system provided in the present application is a three-piece catadioptric optical system, which utilizes the additional function of the quarter-wave plate on the phase of polarized light, the splitting function of the reflective polarizing element, and the reflection function of the partial reflective layer to achieve the folding effect of the imaging light path, which can better compress the height of the main body and improve the imaging quality.

[0066] An optical system according to an exemplary embodiment of the present application includes: a lens barrel, a lens assembly and at least one spacer disposed in the lens barrel, the at least one spacer including a first spacer disposed between a first lens and a second lens and in contact with the first lens; wherein the lens assembly includes: a first lens, a second lens and a third lens in sequence from a first side to a second side along the optical axis; the lens barrel has a front end surface facing the first side and a rear end surface facing the second side; the second side surface of the second lens is a plane; the first side surface of the third lens is a plane, and the second side surface is a convex surface; the optical system can satisfy 0mm≤T23≤0.02mm and 0.7<(L-EP01-CP1) / (CT2+CT3)<1.6, wherein T23 is an air gap between the second lens and the third lens on the optical axis, L is a maximum height of the lens barrel along the optical axis, EP01 is a distance between the front end surface of the lens barrel and the first side surface of the first spacer along the optical axis, CP1 is a maximum thickness of the first spacer along the optical axis, CT2 is a center thickness of the second lens on the optical axis, and CT3 is a center thickness of the third lens on the optical axis. On the one hand, the present application controls the surface shapes of the second lens and the third lens so that the second side surface of the second lens and the first side surface of the third lens are both planes, and the second lens and the third lens can be glued together, which effectively reduces the difficulty of lens molding without increasing the total length, weight and stray light risk of the lens. On the other hand, the present application also reasonably controls the length of the lens barrel and reasonably distributes the thickness of the first spacer, the second lens and the third lens, and ensures the machinability of the first spacer, the second lens and the third lens while ensuring the stability of the system assembly.

[0067] An optical system according to an exemplary embodiment of the present application includes: a lens barrel, a lens assembly and at least one spacer arranged in the lens barrel, the at least one spacer including a first spacer arranged between a first lens and a second lens and in contact with the first lens; wherein the lens assembly includes, in order from the first side to the second side along the optical axis: a first lens, a second lens and a third lens; the lens barrel has a front end face facing the first side and a rear end face facing the second side; the second side surface of the second lens is a plane; the first side surface of the third lens is a plane, and the second side surface is a convex surface; the air interval T23 between the second lens and the third lens on the optical axis satisfies: 0mm≤T23≤0.02mm; and the outer diameter D1s of the first side surface of the first spacer, the inner diameter d1s of the first side surface of the first spacer and the center thickness CT1 of the first lens on the optical axis satisfy: 0.5<(D1s-d1s) / CT1<1.6. On the one hand, the present application controls the surface shapes of the second lens and the third lens so that the second side surface of the second lens and the first side surface of the third lens are both planes, and the second lens and the third lens can be glued together, effectively reducing the difficulty of lens molding without increasing the total length, weight and stray light risk of the lens. On the other hand, the present application also controls the shape of the first lens to ensure its machinability, while also ensuring the stability of the first lens and the first spacer, thereby improving the stability and reliability of the lens assembly.

[0068] An optical system according to an exemplary embodiment of the present application includes: a lens barrel, a lens assembly and at least one spacer arranged in the lens barrel, the at least one spacer including a first spacer arranged between a first lens and a second lens and in contact with the first lens; wherein the lens assembly includes, in order from the first side to the second side along the optical axis: a first lens, a second lens and a third lens; the lens barrel has a front end surface facing the first side and a rear end surface facing the second side; the second side surface of the second lens is a plane; the first side surface of the third lens is a plane, and the second side surface is a convex surface; the air interval T23 between the second lens and the third lens on the optical axis satisfies: 0mm≤T23≤0.02mm; and the outer diameter D1m of the second side surface of the first spacer, the refractive index N2 of the second lens, the refractive index N3 of the third lens, the center thickness CT2 of the second lens on the optical axis, and the center thickness CT3 of the third lens on the optical axis satisfy: 2.0<D1m / (N2×CT2+N3×CT3)<4.5. On the one hand, the present application controls the surface shapes of the second lens and the third lens so that the second side surface of the second lens and the first side surface of the third lens are both planes, and the second lens and the third lens can be glued together, which effectively reduces the difficulty of lens molding without increasing the total length, weight and stray light risk of the lens. On the other hand, the present application also controls the appearance of the second lens and the third lens to ensure their processability, while also ensuring the stability of the second lens, the third lens and the second spacer, thereby improving the stability and reliability of the lens assembly.

[0069] According to some embodiments of the present application, the optical system according to the present application is a small-volume optical system with high-definition imaging quality. In application, the optical system according to the exemplary embodiment of the present application can be suitable for VR equipment. By reasonably setting the center thickness, refractive index, Abbe number, radius of curvature and other parameters of the lens of the optical system, and by reasonably setting the aperture parameters, the purpose of the wide angle of the VR device can be met, and the chromatic aberration of the system can be corrected to improve the imaging quality of the system. By setting spacers between lenses, it can also be beneficial to the processing and molding performance of the lens, reduce the sensitivity of the lens, improve the assembly yield, and meet the miniaturization goal of VR equipment while ensuring the performance of the optical system.

[0070] The optical system provided in the present application can be applied to, for example, a VR device, where the first side can be, for example, a human eye side, and the second side can be, for example, a display side or an image source side. Figure 2 A schematic structural diagram of a VR device according to an exemplary embodiment of the present application is shown. The VR device includes, in sequence from the first side to the second side along the optical axis: a receiving part J, an optical system C, and a transmitting part F. Figure 2 The receiving part J in the optical system may be, for example, a human eye. The optical system C may be an optical system provided by any of the above-mentioned embodiments, and the transmitting part F may be a display screen. The transmitting part F is used to transmit a light signal, which may include image information; the optical system is arranged in the light emitting direction of the transmitting part, and the third lens is arranged closer to the transmitting part than the first lens, and the optical system is used to modulate the light signal emitted by the transmitting part and transmit it to the human eye. Exemplarily, the image light on the display screen is refracted and reflected multiple times by the third lens, the second lens, the first lens, the quarter-wave plate, and the reflective polarizing element, and is finally projected to the user's eyes.

[0071] Specific embodiments of the optical system applicable to the above-mentioned embodiments will be further described below with reference to the accompanying drawings.

[0072] Example 1

[0073] Figure 3A FIG. 1 shows a schematic diagram of the structure of an optical system according to Embodiment 1 of the present application. Figure 3AAs shown, the optical system includes: a lens barrel P0 and a lens assembly, a reflection assembly and at least one spacer arranged in the lens barrel P0, wherein the lens assembly includes a first lens E1, a second lens E2 and a third lens E3 in sequence from the first side to the second side along the optical axis. The reflection assembly may include a reflective polarizing element RP arranged on the first side of the first lens, a quarter wave plate QWP arranged on the first side of the second lens and a partial reflection layer BS arranged on the second side of the third lens. At least one spacer includes a first spacer P1 arranged between the first lens and the second lens and in contact with the first lens, and at least one spacer also includes a second spacer P01 arranged between the lens barrel and the first side of the first lens. The above-mentioned spacer can block the entry of extra external light, so that the lens and the lens barrel are better supported, and enhance the structural stability of the optical system.

[0074] Table 1 shows the basic parameters of the optical system of Example 1, where the units of the radius of curvature and thickness are both in millimeters (mm). Table 1 only lists the correspondence between the surface numbers of some surfaces and some components. Due to the problem of common surfaces between adjacent components, it is not convenient to mark all components in Table 1 with common surfaces.

[0075]

[0076]

[0077] Table 1

[0078] Exemplarily, when the optical system is applied to, for example, a VR device, the first side may be, for example, the human eye side, and the second side may be, for example, the display side or the image source side. Referring to Table 1, the receiving part may be the human eye, and the transmitting part may be the display screen. The light from the transmitting part sequentially passes through the third lens E3, the second lens E2, the quarter wave plate QWP, the first lens E1, and reaches the reflective polarizing element RP, is reflected at the reflective polarizing element RP and passes through the first lens E1, the quarter wave plate QWP, the second lens E2, and the third lens E3 again, and then the light beam is reflected again at the partial reflection layer BS on the second side surface S6 of the third mirror E3 and sequentially passes through the third lens E3, the second lens E2, the quarter wave plate QWP, the first lens E1 to reach the reflective polarizing element RP, passes through the aperture STO and finally exits toward the human eye side. In an exemplary embodiment, the partial reflection layer BS may be a semi-transparent and semi-reflective film layer coated on the second side surface S6 of the third mirror E3.

[0079] In Example 1, the first side surface S1 and the second side surface S2 of the first lens E1, the first side surface S3 of the second lens E2, and the second side surface S6 of the third lens E3 are aspherical surfaces, and the surface shape x of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0080]

[0081] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 2 shows the cone coefficients and high-order coefficients A4, A6, A8 and A9 that can be used for each aspheric mirror surface S1-S3 and S6 in Example 1. 10 .

[0082] Face number Cone coefficient A4 A6 A8 A10 S1 0.0000 1.41E-01 1.72E-02 0.00E+00 0.00E+00 S2 0.0000 1.09E+01 7.17E-01 -1.83E-01 -6.30E-02 S3 0.0000 8.87E-01 -1.35E-01 7.21E-03 -2.87E-03 S6 0.0000 7.39E+00 1.21E+00 7.83E-02 -4.19E-02

[0083] Table 2

[0084] Table 3 gives the basic parameters of the lens barrel and the spacer of the optical system of Example 1. The units of each parameter in Table 3 are millimeters (mm).

[0085] Parameter name Example 1 d1s(mm) 36.74 d1m(mm) 37.88 D1s(mm) 39.41 D1m(mm) 40.28 d0s(mm) 34.15 D0s(mm) 40.82 D0m(mm) 45.71 EP01(mm) 1.54 CP1(mm) 2.68 d01s(mm) 36.09 D01s(mm) 39.35 EP001(mm) 1.40 L(mm) 10.07

[0086] Table 3

[0087] Example 2

[0088] Figure 3B The schematic diagram of the structure of the optical system according to Embodiment 2 of the present application is shown. In this embodiment and the following embodiments, for the sake of brevity, some descriptions similar to Embodiment 1 will be omitted.

[0089] like Figure 3B As shown, the optical system of embodiment 2 includes a lens barrel P0 and a lens assembly, a reflection assembly and at least one spacer arranged in the lens barrel P0, wherein the lens assembly includes a first lens E1, a second lens E2 and a third lens E3 in sequence from the first side to the second side along the optical axis. The reflection assembly may include a reflective polarizing element RP arranged on the first side of the first lens, a quarter wave plate QWP arranged on the first side of the second lens and a partial reflection layer BS arranged on the second side of the third lens. At least one spacer includes a first spacer P1 arranged between the first lens and the second lens and in contact with the first lens, and at least one spacer also includes a second spacer P01 arranged between the lens barrel and the first side of the first lens. The above-mentioned spacer can block the entry of extra external light, so that the lens and the lens barrel are better supported, and enhance the structural stability of the optical system.

[0090] The lens assembly and the reflection assembly of the optical system of Example 2 are exactly the same as the lens assembly and the reflection assembly of the optical system of Example 1, respectively. The basic parameters thereof are detailed in Tables 1 and 2 and will not be described in detail.

[0091] Table 4 shows basic parameters of the lens barrel and spacers of the optical system of Example 2. The units of each parameter in Table 4 are millimeters (mm).

[0092]

[0093]

[0094] Table 4

[0095] Figure 4A The axial chromatic aberration curves of the optical systems of Example 1 and Example 2 are shown, which indicate the deviation of the convergent focus of light rays of different wavelengths after passing through the lens. Figure 4B Astigmatism curves of the optical systems of Example 1 and Example 2 are shown, which represent meridional field curvature and sagittal field curvature. Figure 4C The distortion curves of the optical systems of Example 1 and Example 2 are shown, which represent the distortion values ​​corresponding to different half-field angles. FIG. 4A to FIG. 4C It can be seen that the optical systems provided in Example 1 and Example 2 can achieve good imaging quality.

[0096] Example 3

[0097] Figure 5A FIG. 4 shows a schematic diagram of the structure of an optical system according to Embodiment 3 of the present application. Figure 5A As shown, the optical system includes: a lens barrel P0 and a lens assembly, a reflection assembly and at least one spacer arranged in the lens barrel P0, wherein the lens assembly includes a first lens E1, a second lens E2 and a third lens E3 in sequence from the first side to the second side along the optical axis. The reflection assembly may include a reflective polarizing element RP arranged on the second side of the first lens, a quarter wave plate QWP arranged on the second side of the second lens and a partial reflection layer BS arranged on the second side of the third lens. At least one spacer includes a first spacer P1 arranged between the first lens and the second lens and in contact with the first lens, and at least one spacer also includes a second spacer P01 arranged between the lens barrel and the first side of the first lens. The above-mentioned spacer can block the entry of extra external light, so that the lens and the lens barrel can be better supported, and the structural stability of the optical system is enhanced.

[0098] Table 5 shows the basic parameters of the optical system of Example 3, where the units of the radius of curvature and thickness are both in millimeters (mm). Table 5 only lists the correspondence between the surface numbers of some surfaces and some components. Due to the problem of common surfaces between adjacent components, it is not convenient to mark all components in Table 5.

[0099]

[0100]

[0101] Table 5

[0102] Exemplarily, when the optical system is applied to, for example, a VR device, the first side may be, for example, the human eye side, and the second side may be, for example, the display side or the image source side. Referring to Table 5, the receiving part may be the human eye, and the transmitting part may be the display screen. The light from the transmitting part sequentially passes through the third lens E3, the quarter wave plate QWP, and the second lens E2 to reach the reflective polarizing element RP, is reflected at the reflective polarizing element RP and passes through the second lens E2, the quarter wave plate QWP, and the third lens E3 again, and then the light beam is reflected again at the partial reflection layer BS on the second side surface S6 of the third mirror E3 and sequentially passes through the third lens E3, the quarter wave plate QWP, the second lens E2, the reflective polarizing element RP and the first lens E1, passes through the aperture STO and finally exits toward the human eye side. In an exemplary embodiment, the partial reflection layer BS may be a semi-transparent and semi-reflective film layer coated on the second side surface S6 of the third mirror E3.

[0103] In Example 3, the first side surface S1 of the first lens E1, the first side surface S3 of the second lens E2, and the second side surface S6 of the third lens E3 are aspherical surfaces, wherein the surface shape of each aspherical surface can be defined by the formula (1) given in the above Example 1. Table 6 shows the conic coefficients and high-order coefficients A4, A6, A8 and A9 of each aspherical mirror surface S1-S3 and S6 that can be used in Example 3. 10 .

[0104] Face number Cone coefficient A4 A6 A8 A10 S1 0.0000 1.04E-05 -6.39E-09 -7.01E-11 0.00E+00 S3 0.0000 -2.17E-06 -2.38E-08 3.89E-11 -3.58E-14 S6 0.0000 1.78E-06 -1.96E-09 -4.85E-12 0.00E+00

[0105] Table 6

[0106] Table 7 gives the basic parameters of the lens barrel and the spacer of the optical system of Example 3. The units of each parameter in Table 7 are millimeters (mm).

[0107] Parameter name Example 3 d1s(mm) 38.52 d1m(mm) 39.24 D1s(mm) 41.19 D1m(mm) 41.64 d0s(mm) 34.71 D0s(mm) 42.60 D0m(mm) 45.94 EP01(mm) 1.54 CP1(mm) 2.19 d01s(mm) 35.43 D01s(mm) 41.13 EP001(mm) 1.40 L(mm) 10.43

[0108] Table 7

[0109] Example 4

[0110] Figure 5B A schematic structural diagram of an optical system according to Example 4 of the present application is shown.

[0111] like Figure 5BAs shown, the optical system of embodiment 4 includes a lens barrel P0 and a lens assembly, a reflection assembly and at least one spacer arranged in the lens barrel P0, wherein the lens assembly includes a first lens E1, a second lens E2 and a third lens E3 in sequence from the first side to the second side along the optical axis. The reflection assembly may include a reflective polarizing element RP arranged on the second side of the first lens, a quarter wave plate QWP arranged on the second side of the second lens and a partial reflection layer BS arranged on the second side of the third lens. At least one spacer includes a first spacer P1 arranged between the first lens and the second lens and in contact with the first lens, and at least one spacer also includes a second spacer P01 arranged between the lens barrel and the first side of the first lens. The above-mentioned spacer can block the entry of extra external light, so that the lens and the lens barrel are better supported, and enhance the structural stability of the optical system.

[0112] The lens assembly and the reflection assembly of the optical system of Example 4 are exactly the same as the lens assembly and the reflection assembly of the optical system of Example 3, respectively. The basic parameters thereof are detailed in Tables 5 and 6 and will not be described in detail.

[0113] Table 8 shows basic parameters of the lens barrel and spacers of the optical system of Example 4. The units of each parameter in Table 8 are millimeters (mm).

[0114] Parameter name Example 4 d1s(mm) 38.52 d1m(mm) 39.24 D1s(mm) 40.67 D1m(mm) 41.49 d0s(mm) 34.07 D0s(mm) 41.97 D0m(mm) 46.26 EP01(mm) 1.72 CP1(mm) 2.16 d01s(mm) 35.30 D01s(mm) 40.50 EP001(mm) 1.40 L(mm) 10.43

[0115] Table 8

[0116] Fig. 6A The axial chromatic aberration curves of the optical systems of Examples 3 and 4 are shown, which indicate the deviation of the convergent focus of light rays of different wavelengths after passing through the lens. Figure 6B Astigmatism curves of the optical systems of Examples 3 and 4 are shown, which represent meridional field curvature and sagittal field curvature. Figure 6C The distortion curves of the optical systems of Example 3 and Example 4 are shown, which represent the distortion magnitude values ​​corresponding to different half-field angles. FIG. 6A to FIG. 6C It can be seen that the optical systems provided in Examples 3 and 4 can achieve good imaging quality.

[0117] Example 5

[0118] Fig. 7A FIG. 5 shows a schematic diagram of the structure of an optical system according to Embodiment 5 of the present application. Fig. 7AAs shown, the optical system includes: a lens barrel P0 and a lens assembly, a reflection assembly and at least one spacer arranged in the lens barrel P0, wherein the lens assembly includes a first lens E1, a second lens E2 and a third lens E3 in sequence from the first side to the second side along the optical axis. The reflection assembly may include a reflective polarizing element RP arranged on the first side of the second lens, a quarter wave plate QWP arranged on the second side of the second lens and a partial reflection layer BS arranged on the second side of the third lens. At least one spacer includes a first spacer P1 arranged between the first lens and the second lens and in contact with the first lens, and at least one spacer also includes a second spacer P01 arranged between the lens barrel and the first side of the first lens. The above-mentioned spacer can block the entry of extra external light, so that the lens and the lens barrel are better supported, and enhance the structural stability of the optical system.

[0119] Table 9 shows the basic parameters of the optical system of Example 5, where the units of the radius of curvature and thickness are both in millimeters (mm). Table 9 only lists the correspondence between the surface numbers of some surfaces and some components. Due to the problem of common surfaces between adjacent components, it is not convenient to mark all components in Table 9 where there are common surfaces.

[0120]

[0121] Table 9

[0122] Exemplarily, when the optical system is applied to, for example, a VR device, the first side may be, for example, the human eye side, and the second side may be, for example, the display side or the image source side. Referring to Table 9, the receiving part may be the human eye, and the transmitting part may be the display screen. The light from the transmitting part sequentially passes through the third lens E3, the quarter wave plate QWP, and the second lens E2 to reach the reflective polarizing element RP, is reflected at the reflective polarizing element RP and passes through the second lens E2, the quarter wave plate QWP, and the third lens E3 again, and then the light beam is reflected again at the partial reflection layer BS on the second side surface S6 of the third mirror E3 and sequentially passes through the third lens E3, the quarter wave plate QWP, the second lens E2, the reflective polarizing element RP and the first lens E1, passes through the aperture STO and finally exits toward the human eye side. In an exemplary embodiment, the partial reflection layer may be a semi-transparent and semi-reflective film layer coated on the second side surface S6 of the third mirror E3.

[0123] In Example 5, the first side surface S1 and the second side surface S2 of the first lens E1, the first side surface S3 of the second lens E2, and the second side surface S6 of the third lens E3 are aspherical surfaces, wherein the surface shape of each aspherical surface can be defined by the formula (1) given in the above Example 1. Table 10 shows the conic coefficients and high-order coefficients A4, A6, A8 and A9 of each aspherical mirror surface S1-S3 and S6 that can be used in Example 5. 10 .

[0124] Face number Cone coefficient A4 A6 A8 A10 S1 0.0000 -4.16E-05 5.10E-08 -6.30E-10 0.00E+00 S2 0.0000 -4.58E-05 5.48E-09 -3.75E-10 1.64E-13 S3 0.0000 6.72E-06 -1.06E-08 2.92E-11 -6.02E-14 S6 0.0000 3.59E-06 -5.83E-10 -6.79E-12 0.00E+00

[0125] Table 10

[0126] Table 11 gives the basic parameters of the lens barrel and spacers of the optical system of Example 5. The units of each parameter in Table 11 are millimeters (mm).

[0127] Parameter name Example 5 d1s(mm) 37.00 d1m(mm) 37.00 D1s(mm) 44.32 D1m(mm) 44.32 d0s(mm) 25.63 D0s(mm) 33.09 D0m(mm) 47.70 EP01(mm) 1.64 CP1(mm) 0.10 d01s(mm) 26.92 D01s(mm) 31.83 EP001(mm) 1.40 L(mm) 15.79

[0128] Table 11

[0129] Example 6

[0130] Figure 7B A schematic structural diagram of an optical system according to Example 6 of the present application is shown.

[0131] like Figure 7B As shown, the optical system of Example 6 includes a lens barrel P0 and a lens assembly, a reflection assembly and at least one spacer arranged in the lens barrel P0, wherein the lens assembly includes a first lens E1, a second lens E2 and a third lens E3 in sequence from the first side to the second side along the optical axis. The reflection assembly may include a reflective polarizing element RP arranged on the first side of the second lens, a quarter wave plate QWP arranged on the second side of the second lens and a partial reflection layer BS arranged on the second side of the third lens. At least one spacer includes a first spacer P1 arranged between the first lens and the second lens and in contact with the first lens, and at least one spacer also includes a second spacer P01 arranged between the lens barrel and the first side of the first lens. The above-mentioned spacer can block the entry of extra external light, so that the lens and the lens barrel are better supported, and enhance the structural stability of the optical system.

[0132] The lens assembly and the reflection assembly of the optical system of Example 6 are exactly the same as the lens assembly and the reflection assembly of the optical system of Example 5, respectively. Their basic parameters are detailed in Tables 9 and 10 and will not be described in detail.

[0133] Table 12 shows basic parameters of the lens barrel and spacers of the optical system of Example 6. The units of each parameter in Table 12 are millimeters (mm).

[0134]

[0135]

[0136] Table 12

[0137] Fig. 8A The axial chromatic aberration curves of the optical systems of Examples 5 and 6 are shown, which indicate the deviation of the convergent focus of light rays of different wavelengths after passing through the lens. Figure 8B Astigmatism curves of the optical systems of Examples 5 and 6 are shown, which indicate meridional field curvature and sagittal field curvature. Figure 8C The distortion curves of the optical systems of Example 5 and Example 6 are shown, which represent the distortion values ​​corresponding to different half-field angles. FIG. 8A to FIG. 8C It can be seen that the optical systems provided in Examples 5 and 6 can achieve good imaging quality.

[0138] Example 7

[0139] Fig.9A FIG. 2 shows a schematic diagram of the structure of an optical system according to Embodiment 7 of the present application. Fig.9A As shown, the optical system includes: a lens barrel P0 and a lens assembly, a reflection assembly and at least one spacer arranged in the lens barrel P0, wherein the lens assembly includes a first lens E1, a second lens E2 and a third lens E3 in sequence from the first side to the second side along the optical axis. The reflection assembly may include a reflective polarizing element RP and a quarter wave plate QWP arranged on the first side of the second lens, and a partial reflection layer BS arranged on the first side of the third lens. At least one spacer includes a first spacer P1 arranged between the first lens and the second lens and in contact with the first lens, and at least one spacer also includes a second spacer P01 arranged between the lens barrel and the first side of the first lens. The above-mentioned spacer can block the entry of extra external light, so that the lens and the lens barrel can be better supported, and the structural stability of the optical system is enhanced.

[0140] In an exemplary embodiment, the reflective polarizing element and the quarter wave plate are combined and attached in one step instead of two steps, thereby reducing the angular position error caused by attachment and improving the imaging quality.

[0141] Table 13 shows the basic parameters of the optical system of Example 7, where the units of the radius of curvature and thickness are both in millimeters (mm). Table 13 only lists the correspondence between the surface numbers of some surfaces and some components. Due to the problem of common surfaces between adjacent components, it is not convenient to mark all components in Table 13 where there are common surfaces.

[0142]

[0143]

[0144] Table 13

[0145] Exemplarily, when the optical system is applied to, for example, a VR device, the first side may be, for example, the human eye side, and the second side may be, for example, the display side or the image source side. Referring to Table 13, the receiving part may be the human eye, and the transmitting part may be the display screen. The light from the transmitting part sequentially passes through the third lens E3, the second lens E2, and the quarter-wave plate QWP to reach the reflective polarizing element RP, is reflected at the reflective polarizing element RP and passes through the quarter-wave plate QWP and the second lens E2 again, and then the light beam is reflected again at the partial reflection layer BS on the first side surface S5 of the third mirror E3 and sequentially passes through the second lens E2, the quarter-wave plate QWP, the reflective polarizing element RP and the first lens E1, passes through the aperture STO and finally exits toward the human eye side. In an exemplary embodiment, the partial reflection layer may be a semi-transparent and semi-reflective film layer coated on the first side surface S5 of the third mirror E3.

[0146] In Example 7, the first side surface S1 and the second side surface S2 of the first lens E1, the first side surface S3 of the second lens E2, and the second side surface S6 of the third lens E3 are aspherical surfaces, wherein the surface shape of each aspherical surface can be defined by the formula (1) given in the above Example 1. Table 14 shows the conic coefficients and high-order coefficients A4, A6, A8 and A9 of each aspherical mirror surface S1-S3 and S6 that can be used in Example 7. 10 .

[0147] Face number Cone coefficient A4 A6 A8 A10 S1 0.0000 -9.66E-05 4.68E-07 -9.35E-10 0.00E+00 S2 0.0000 -8.03E-05 -1.01E-07 3.44E-09 -2.45E-11 S3 0.0000 -3.75E-06 1.61E-08 -1.31E-11 -1.75E-15 S6 -556.1512 0.00E+00 1.88E-06 7.97E-10 -3.27E-12

[0148] Table 14

[0149] Table 15 gives the basic parameters of the lens barrel and spacers of the optical system of Example 7. The units of each parameter in Table 15 are millimeters (mm).

[0150] Parameter name Example 7 d1s(mm) 47.03 d1m(mm) 47.03 D1s(mm) 53.14 D1m(mm) 53.14 d0s(mm) 26.42 D0s(mm) 33.53 D0m(mm) 57.44 EP01(mm) 1.20 CP1(mm) 0.10 d01s(mm) 27.35 D01s(mm) 31.73 EP001(mm) 1.40 L(mm) 23.45

[0151] Table 11

[0152] Example 8

[0153] Fig. 9B A schematic structural diagram of an optical system according to Example 8 of the present application is shown.

[0154] like Fig. 9BAs shown, the optical system of Example 8 includes a lens barrel P0 and a lens assembly, a reflection assembly and at least one spacer arranged in the lens barrel P0, wherein the lens assembly includes a first lens E1, a second lens E2 and a third lens E3 in sequence from the first side to the second side along the optical axis. The reflection assembly may include a reflective polarizing element RP and a quarter wave plate QWP arranged on the first side of the second lens, and a partial reflection layer BS arranged on the first side of the third lens. At least one spacer includes a first spacer P1 arranged between the first lens and the second lens and in contact with the first lens, and at least one spacer also includes a second spacer P01 arranged between the lens barrel and the first side of the first lens. The above-mentioned spacer can block the entry of extra external light, so that the lens and the lens barrel are better supported, and enhance the structural stability of the optical system.

[0155] In an exemplary embodiment, the reflective polarizing element and the quarter wave plate are combined and attached in one step instead of two steps, thereby reducing the angular position error caused by attachment and improving the imaging quality.

[0156] The lens assembly and the reflection assembly of the optical system of Example 8 are exactly the same as the lens assembly and the reflection assembly of the optical system of Example 7, respectively. Their basic parameters are detailed in Tables 9 and 10 and will not be described in detail.

[0157] Table 12 shows basic parameters of the lens barrel and spacers of the optical system of Example 8. The units of each parameter in Table 12 are millimeters (mm).

[0158] Parameter name Example 8 d1s(mm) 47.03 d1m(mm) 47.03 D1s(mm) 52.25 D1m(mm) 52.25 d0s(mm) 26.02 D0s(mm) 33.53 D0m(mm) 56.94 EP01(mm) 1.07 CP1(mm) 0.10 d01s(mm) 26.83 D01s(mm) 31.73 EP001(mm) 1.53 L(mm) 23.45

[0159] Table 12

[0160] Fig. 10A The axial chromatic aberration curves of the optical systems of Examples 7 and 8 are shown, which indicate the deviation of the convergent focus of light rays of different wavelengths after passing through the lens. Fig. 10B Astigmatism curves of the optical systems of Examples 7 and 8 are shown, which indicate meridional field curvature and sagittal field curvature. Fig. 10C The distortion curves of the optical systems of Example 7 and Example 8 are shown, which represent the distortion values ​​corresponding to different half-field angles. FIG. 10A to FIG. 10C It can be seen that the optical systems provided in Examples 7 and 8 can achieve good imaging quality.

[0161] In summary, the optical systems of Examples 1 to 8 satisfy the relationship shown in Table 13.

[0162] Conditional / Example 1 2 3 4 5 6 7 8 d1m / (D1m-d1m) 15.77 10.67 16.34 17.42 5.06 4.86 7.70 9.01 (L-EP01-CP1) / (CT2+CT3) 0.91 1.29 0.72 0.71 1.42 1.42 1.55 1.56 d1s / (N1×CT1) 6.28 6.67 15.25 15.25 3.73 3.73 5.72 5.72 L / (T12+T23) 14.39 14.44 11.59 11.59 17.55 17.55 23.34 23.34 (D1s-d1s) / CT1 0.70 0.95 1.58 1.27 1.09 1.14 1.10 0.94 D1m / (N2×CT2+N3×CT3) 4.09 4.33 2.92 2.91 2.85 2.87 2.37 2.33 TD / (D0m-D0s) 2.25 1.99 3.49 2.72 1.18 1.45 0.87 0.89 EP01 / CT1 0.40 0.43 0.91 1.02 0.24 0.24 0.22 0.19 CP1 / T12 3.83 0.14 3.12 3.08 0.14 0.14 0.10 0.10 d0s / d1s 0.93 0.89 0.90 0.88 0.69 0.69 0.56 0.55 (D0s-d0s) / (D01s-d01s) 2.05 2.10 1.39 1.52 1.52 1.49 1.63 1.53 CT1 / EP001 2.74 2.74 1.21 1.21 4.77 4.77 3.96 3.62

[0163] Table 13

[0164] The present application also provides a VR device, which includes an optical system and a transmitter provided in any of the above embodiments. The transmitter is used to transmit a light signal, which may include image information. The optical system is arranged in the light emitting direction of the transmitter, and the third lens is arranged closer to the transmitter than the first lens, and the optical system is used to modulate the light signal emitted by the transmitter and transmit it to the human eye.

[0165] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of protection involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of the present application. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) to form a technical solution.

Claims

1. An optical system, characterized in that include: A lens barrel and a lens assembly disposed in the lens barrel, wherein: The lens assembly includes, in order from the first side to the second side along the optical axis: a first lens, a second lens and a third lens; The lens barrel has a front end surface facing the first side and a rear end surface facing the second side; The second side surface of the second lens is a plane; The first side surface of the third lens is a plane surface, and the second side surface is a convex surface; The interval T23 between the second lens and the third lens on the optical axis satisfies: 0 mm ≤ T23 ≤ 0.02 mm or T23 = 0.2000 mm; and The interval T12 between the first lens and the second lens on the optical axis, the interval T23 between the second lens and the third lens on the optical axis, and the maximum height L of the lens barrel along the optical axis satisfy: 11.0<L / (T12+T23)<24.

0.

2. The optical system according to claim 1, characterized in that The optical system further includes at least one spacer disposed within the lens barrel; The at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein, An outer diameter D1m of the second side surface of the first spacer and an inner diameter d1m of the second side surface of the first spacer satisfy the following: 4.5<d1m / (D1m-d1m)<17.

5.

3. The optical system according to claim 1, characterized in that The optical system further includes at least one spacer disposed within the lens barrel; The at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein, The maximum height L of the lens barrel along the optical axis, the distance EP01 between the front end face of the lens barrel and the first side face of the first spacer along the optical axis, the maximum thickness CP1 of the first spacer along the optical axis, the center thickness CT2 of the second lens on the optical axis and the center thickness CT3 of the third lens on the optical axis satisfy: 0.7<(L-EP01-CP1) / (CT2+CT3)<1.

6.

4. The optical system according to claim 1, characterized in that The optical system further includes at least one spacer disposed within the lens barrel; The at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein, An inner diameter d1s of the first side surface of the first spacer, a refractive index N1 of the first lens, and a center thickness CT1 of the first lens on the optical axis satisfy: 3.5<d1s / (N1×CT1)<15.

5.

5. The optical system according to claim 1, characterized in that The optical system further includes at least one spacer disposed within the lens barrel; The at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein, An outer diameter D1s of the first side surface of the first spacer, an inner diameter d1s of the first side surface of the first spacer, and a center thickness CT1 of the first lens on the optical axis satisfy: 0.5<(D1s-d1s) / CT1<1.

6.

6. The optical system according to claim 1, characterized in that The optical system further includes at least one spacer disposed within the lens barrel; The at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein, The outer diameter D1m of the second side surface of the first spacer, the refractive index N2 of the second lens, the refractive index N3 of the third lens, the center thickness CT2 of the second lens on the optical axis and the center thickness CT3 of the third lens on the optical axis satisfy: 2.0<D1m / (N2×CT2+N3×CT3)<4.

5.

7. The optical system according to claim 1, characterized in that The optical system further includes at least one spacer disposed within the lens barrel; The at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein, A distance EP01 between the front end surface of the lens barrel and the first side surface of the first spacer along the optical axis and a center thickness CT1 of the first lens on the optical axis satisfy: 0.1<EP01 / CT1<1.

1.

8. The optical system according to claim 1, characterized in that The optical system further includes at least one spacer disposed within the lens barrel; The at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein, A maximum thickness CP1 of the first spacer along the optical axis and a distance T12 between the first lens and the second lens on the optical axis satisfy: 0≤CP1 / T12<4.

0.

9. The optical system according to claim 1, characterized in that The optical system further includes at least one spacer disposed within the lens barrel; The at least one spacer includes a first spacer disposed between the first lens and the second lens and in contact with the first lens; wherein, An inner diameter d0s of the front end surface of the lens barrel and an inner diameter d1s of the first side surface of the first spacer satisfy the following relationship: 0.5<d0s / d1s<1.

0.

10. The optical system according to any one of claims 1 to 9, characterized in that: The axial distance TD from the first side surface of the first lens to the second side surface of the third lens, the outer diameter D0m of the rear end surface of the lens barrel, and the outer diameter D0s of the front end surface of the lens barrel satisfy: 0.5<TD / (D0m-D0s)<3.

5.

11. The optical system according to any one of claims 2 to 9, characterized in that: The at least one spacer further includes a second spacer disposed between the lens barrel and the first side surface of the first lens.

12. The optical system according to claim 11, characterized in that The outer diameter D0s of the front end surface of the lens barrel, the inner diameter d0s of the front end surface of the lens barrel, the outer diameter D01s of the first side surface of the second spacer and the inner diameter d01s of the first side surface of the second spacer satisfy: 1.3<(D0s-d0s) / (D01s-d01s)<2.

2.

13. The optical system according to claim 11, characterized in that The center thickness CT1 of the first lens on the optical axis and the distance EP001 between the front end surface of the lens barrel and the first side surface of the second spacer along the optical axis direction satisfy: 1.0<CT1 / EP001<5.

0.

14. The optical system according to any one of claims 1 to 9, characterized in that: The optical system also includes a reflective component, which includes a reflective polarizing element, a quarter wave plate and a partial reflective layer in sequence from the first side to the second side along the optical axis, wherein the reflective polarizing element and the quarter wave plate are arranged on at least one of the first side surface and the second side surface of the first lens and the second lens, and the partial reflective layer is arranged on the first side surface or the second side surface of the third lens.

15. A VR device, characterized in that: include: An optical system as claimed in any one of claims 1 to 14; as well as A transmitting unit, used for transmitting a light signal, wherein the light signal includes image information; The optical system is arranged in the light emitting direction of the emitting part, and the third lens is arranged closer to the emitting part than the first lens. The optical system is used to modulate the light signal emitted by the emitting part and transmit it to the human eye.

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