Visual optical system

Abstract

The utility model discloses a visual optical system. The visual optical system sequentially comprises a first optical system and a second optical system from a first side to a second side, the first optical system sequentially comprises a reflective polarizing element, a quarter-wave plate and a first lens from the first side to the second side along a first optical axis; wherein the first lens has positive focal power, the first side surface of the first lens is a concave surface, and the second side surface of the first lens is a convex surface; the second optical system sequentially comprises a first lens with positive focal power and a second lens with focal power from the first side to the second side along the second optical axis; wherein the first side surface of the second lens is a concave surface; the number of the lenses with the focal power in the second optical system is two; the curvature radius R1m of the first side surface of the first lens, the curvature radius R2m of the second side surface of the first lens, the combined focal length f12e of the first lens and the second lens and the distance TDe from the first side surface of the first lens to the second side surface of the second lens on the second optical axis meet the following conditions: 0.8 lt; (R1m / R2m) / (f12e / TDe) lt; 2.0.

Description

Technical Field

[0001] This application relates to the field of optical devices, and particularly to a visual optical system. Background Art

[0002] With the continuous development of mixed reality technology, visual optical systems with eye-tracking functions are becoming increasingly important. A visual optical system with an eye-tracking function is an important part of a mixed reality device, which can capture pupil information, locate individual information, and ensure information security. However, such visual optical systems with eye-tracking functions usually have problems such as a relatively long overall body length, a relatively heavy weight, and a center of gravity position being relatively forward, which affect the user experience. Summary of the Utility Model

[0003] One aspect of this application provides such a visual optical system, which sequentially includes a first optical system and a second optical system from a first side to a second side. The first optical system sequentially includes a reflective polarizing element, a quarter-wave plate, and a first lens along a first optical axis from the first side to the second side; wherein, the first lens has a positive optical power, its first side is concave, and its second side is convex. The second optical system sequentially includes a first lens with a positive optical power and a second lens with an optical power along a second optical axis from the first side to the second side; wherein, the first side of the second lens is concave. The number of lenses with optical power in the second optical system is two. The radius of curvature R1m of the first side of the first lens, the radius of curvature R2m of the second side of the first lens, the combined focal length f12e of the first lens and the second lens, and the distance TDe on the second optical axis from the first side of the first lens to the second side of the second lens satisfy: 0.8 < (R1m / R2m) / (f12e / TDe) < 2.0.

[0004] According to an exemplary embodiment of this application, the central thickness CT2e of the second lens on the second optical axis and the radius of curvature R3e of the first side of the second lens satisfy: -1.25 < CT2e / R3e < -0.15.

[0005] According to an exemplary embodiment of this application, the effective focal length f1e of the first lens and the effective focal length f2e of the second lens satisfy: -1.1 ≤ (f1e + f2e) / (f1e - f2e) ≤ 2.0.

[0006] According to an exemplary embodiment of this application, the radius of curvature R1e of the first side of the first lens and the radius of curvature R2e of the second side of the first lens satisfy: -1.95 < (R1e - R2e) / (R1e + R2e) < 1.05.

[0007] According to an exemplary embodiment of the present application, the effective focal length f1e of the first lens and the radius of curvature R1e of the first side surface of the first lens satisfy: 0 < f1e / |R1e| < 1.8.

[0008] According to an exemplary embodiment of the present application, the total effective focal length f of the visual optical system, the refractive index N1e of the first lens, and the refractive index N1m of the first lens satisfy: 0.5 mm < f × (N1e / N1m) < 0.75 mm.

[0009] According to an exemplary embodiment of the present application, the central thickness CT1m of the first lens on the first optical axis, the central thickness CTR of the reflective polarizing element on the first optical axis, the central thickness CTQ of the quarter-wave plate on the first optical axis, and the total effective focal length f of the visual optical system satisfy: 18.85 < (CT1m + CTR + CTQ) / f < 24.4.

[0010] According to an exemplary embodiment of the present application, the total effective focal length f of the visual optical system and the effective focal length f1e of the first lens satisfy: 0.15 < f / f1e < 1.35.

[0011] According to an exemplary embodiment of the present application, the combined focal length f12e of the first lens and the second lens, the combined focal length fzm of the reflective polarizing element, the quarter-wave plate, and the first lens, and the radius of curvature R2m of the second side surface of the first lens satisfy: -4.25 mm < f12e × (fzm / R2m) < -3.25 mm.

[0012] According to an exemplary embodiment of the present application, the combined focal length f12e of the first lens and the second lens, the effective focal length f1m of the first lens, and the central thickness CT1m of the first lens on the first optical axis satisfy: 12.3 mm < f12e × (f1m / CT1m) < 15.95 mm.

[0013] According to an exemplary embodiment of the present application, the central thickness CT1e of the first lens on the second optical axis, the central thickness CT2e of the second lens on the second optical axis, and the total effective focal length f of the visual optical system satisfy: 0.45 < (CT1e + CT2e) / f < 1.35.

[0014] According to an exemplary embodiment of the present application, the total effective focal length f of the visual optical system, the Abbe number V2e of the second lens, and the Abbe number V1e of the first lens satisfy: 0.5 mm < f × (V2e / V1e) < 0.7 mm.

[0015] According to an exemplary embodiment of the present application, the distance TDe on the second optical axis from the first side surface of the first lens to the second side surface of the second lens, the central thickness CTR of the reflective polarizing element on the first optical axis, and the central thickness CTQ of the quarter-wave plate on the first optical axis satisfy: 1.8 < TDe / (CTR + CTQ) < 4.45.

[0016] According to an exemplary embodiment of the present application, the combined focal length f12e of the first lens and the second lens and the central thickness CTQ of the quarter-wave plate on the first optical axis satisfy: 5.65 < f12e / CTQ < 7.4.

[0017] According to an exemplary embodiment of the present application, the angle θ between the second optical axis and the first optical axis satisfies: 0° < θ < 90°.

[0018] The visual optical system provided by the present application is configured in a structural form of a combination of a first optical system and a second optical system. Among them, the first optical system includes a first lens, a reflective polarizing element, and a quarter-wave plate, and the second optical system includes two lenses and is a macro system. The second optical system has a large depth-of-field range. By arranging the first optical system on the first side of the second optical system, it is beneficial to reduce the loss of the overall optical performance of the visual optical system. In addition, by constraining (R1m / R2m) / (f12e / TDe) within a reasonable range, the radius of curvature of the first side surface of the first lens can be made smaller, which is beneficial to reducing the size of the image plane of the first optical system; at the same time, the second optical system can also have a smaller total length, reducing the volume of the second optical system, which is beneficial to the combined assembly of the second optical system and the first optical system. Description of the Drawings

[0019] Other features, objects, and advantages of the present application will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings. Among them:

[0020] Figure 1 Shows a schematic structural diagram of the visual optical system according to Embodiment 1 of the present application;

[0021] Figure 2 Shows a schematic structural diagram of the second optical system according to Embodiment 1 of the present application;

[0022] Figure 3 Shows the modulation transfer function curve of the visual optical system according to Embodiment 1 of the present application;

[0023] Figure 4 Shows a schematic structural diagram of the visual optical system according to Embodiment 2 of the present application;

[0024] Figure 5Shows a schematic structural diagram of a second optical system according to Embodiment 2 of the present application;

[0025] Figure 6 Shows the modulation transfer function curve of the visual optical system according to Embodiment 2 of the present application;

[0026] Figure 7 Shows a schematic structural diagram of the visual optical system according to Embodiment 3 of the present application;

[0027] Figure 8 Shows a schematic structural diagram of a second optical system according to Embodiment 3 of the present application;

[0028] Figure 9 Shows the modulation transfer function curve of the visual optical system according to Embodiment 3 of the present application;

[0029] Figure 10 Shows a schematic structural diagram of the visual optical system according to Embodiment 4 of the present application;

[0030] Figure 11 Shows a schematic structural diagram of a second optical system according to Embodiment 4 of the present application;

[0031] Figure 12 Shows the modulation transfer function curve of the visual optical system according to Embodiment 4 of the present application;

[0032] Figure 13 Shows a schematic structural diagram of the visual optical system according to Embodiment 5 of the present application;

[0033] Figure 14 Shows a schematic structural diagram of a second optical system according to Embodiment 5 of the present application; and

[0034] Figure 15 Shows the modulation transfer function curve of the visual optical system according to Embodiment 5 of the present application. Detailed Description of the Invention

[0035] To better understand the present application, more detailed descriptions of various aspects of the present application will be made 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 do not 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.

[0036] It should be noted that in this specification, the expressions such as first, second, and third are only used to distinguish one feature from another feature and do not represent any limitation on the feature. Therefore, without departing from the teachings of the present application, the first lens discussed below may also be referred to as the second lens.

[0037] In the drawings, for ease of explanation, the thickness, dimensions, and shape of the lenses and / or lens elements have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are for illustrative purposes only and are not drawn to an exact scale.

[0038] As used herein, the paraxial region refers to the region near the optical axis. If the surface of a lens and / or lens element is convex and the position of the convex surface is not defined, it means that the surface of the lens and / or lens element is convex at least in the paraxial region; if the surface of a lens and / or lens element is concave and the position of the concave surface is not defined, it means that the surface of the lens and / or lens element is concave at least in the paraxial region. The surface of each lens and / or lens element closest to the first side (e.g., the side closer to the human eye) is referred to as the first side surface of the lens and / or lens element, and the surface of each lens and / or lens element closest to the second side (e.g., the side farther from the human eye) is referred to as the second side surface of the lens and / or lens element.

[0039] It should also be understood that the terms "comprises" and / or "having", when used in this specification, denote the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Further, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". And the term "exemplary" is intended to refer to an example or illustration.

[0040] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0041] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0042] Reference Figure 1 and Figure 2, a first aspect of the present application provides a visual optical system, which may sequentially include a first optical system and a second optical system from a first side to a second side. The first optical system may be configured as a catadioptric optical system. The second optical system is used to collect an image of the user's eyeball and obtain the fixation point information of the human eye based on the collected eyeball image to achieve the function of eye movement tracking. The number of the first optical systems may be one or more. The number of the second optical systems may be one or more. In an example, the visual optical system may include two first optical systems and two second optical systems symmetrically arranged.

[0043] In an exemplary embodiment, the first optical system may include a reflective polarizing element, a quarter-wave plate, and a first lens arranged in sequence along a first optical axis (e.g., Z1 axis) from the first side to the second side. After the light passes through the quarter-wave plate, the polarization state changes. The light with the changed polarization state is reflected or transmitted at the reflective polarizing element, so that the light is catadioptric between the reflective polarizing element and the second side surface of the first lens, effectively shortening the body length of the first optical system.

[0044] In an exemplary embodiment, the first lens may have a positive optical power, its first side surface is concave, and its second side surface is convex.

[0045] In an exemplary embodiment, the reflective polarizing element is attached to the quarter-wave plate and attached to the first side surface of the first lens. Among them, the quarter-wave plate is closer to the first side surface of the first lens than the reflective polarizing element. By combining the reflective polarizing element and the quarter-wave plate together to form a film layer, the adhesion yield of the film layer can be improved.

[0046] In an exemplary embodiment, the first optical system may further include a partial reflection layer, and the partial reflection layer may be attached to the second side surface of the first lens. The partial reflection layer has a semi-transmissive and semi-reflective effect on light. By providing the partial reflection layer and combining it with the reflective polarizing element and the quarter-wave plate, the light can be catadioptric multiple times, effectively reducing the body length of the first optical system.

[0047] In an exemplary embodiment, the second optical system may include a first lens and a second lens arranged in sequence along a second optical axis (e.g., Z2 axis) from the first side to the second side. There may be a spacing distance between the first lens and the second lens, for example, an air gap.

[0048] In an exemplary embodiment, the first lens may have a positive optical power, its first side surface may be convex or concave, and its second side surface may be convex or concave.

[0049] In an exemplary embodiment, the second lens may have a positive or negative optical power, its first side surface may be concave, and its second side surface may be convex or concave.

[0050] In an exemplary embodiment, the second optical system may further include a diaphragm, and the diaphragm may be disposed between the first optical system and the first lens.

[0051] In an exemplary embodiment, the first side may be the side close to the human eye, and the second side may be the side far from the human eye. Correspondingly, the first side surfaces of the respective elements (reflective polarizing element, quarter-wave plate, first lens, first lens, and second lens) may be referred to as the side surfaces close to the human eye, and the second side surfaces may be referred to as the side surfaces far from the human eye.

[0052] In an exemplary embodiment, a display screen may be disposed on the second side of the visual optical system, and the second optical system is located between the first optical system and the display screen. Light rays from the human eye reach the second optical system after passing through the first optical system, and the second optical system receives the above light rays and presents an image. By placing the second optical system on the side of the first optical system away from the human eye, without affecting the performance and function of the first optical system, the visual optical system can be enabled to have an eye movement tracking function, improve the appearance of subsequent devices including the visual optical system, and make the second optical system invisible under visual inspection, thereby improving the aesthetics of the device.

[0053] In an exemplary embodiment, the included angle θ between the second optical axis and the first optical axis may satisfy: 0° < θ < 90°. By controlling the included angle between the second optical axis and the first optical axis, the second optical system can be placed outside the first optical system. While ensuring the performance and function of the first optical system, the second optical system can capture an eye image, thereby realizing the eye movement tracking function.

[0054] In an exemplary embodiment, the radius of curvature R1m of the first side surface of the first lens, the radius of curvature R2m of the second side surface of the first lens, the combined focal length f12e of the first lens and the second lens, and the distance TDe on the second optical axis from the first side surface of the first lens to the second side surface of the second lens may satisfy: 0.8 < (R1m / R2m) / (f12e / TDe) < 1.4. The second optical system includes two lenses and is a macro system. The second optical system has a large depth of field range. In the case where the second optical system has a large depth of field, setting the first optical system on the first side of the second optical system is beneficial to reducing the loss of the overall optical performance of the visual optical system. In addition, by constraining (R1m / R2m) / (f12e / TDe) within a reasonable range, the radius of curvature of the first side surface of the first lens can be made smaller, which is beneficial to reducing the size of the image plane of the first optical system and realizing the miniaturization of the display screen on the second side of the visual optical system; at the same time, the second optical system can have a smaller total length, reducing the volume of the second optical system, which is beneficial to the combined assembly of the second optical system and the first optical system.

[0055] In an exemplary embodiment, the central thickness CT2e of the second lens on the second optical axis and the radius of curvature R3e of the first side surface of the second lens may satisfy: -1.25 < CT2e / R3e < -0.15. By reasonably configuring the ratio of the central thickness of the second lens on the second optical axis to the radius of curvature of the first side surface of the second lens, the effective focal length of the second lens can be effectively controlled, the height of light on the image plane can be increased, and thus the length of the second optical system can be reduced.

[0056] In an exemplary embodiment, the effective focal length f1e of the first lens and the effective focal length f2e of the second lens may satisfy: -1.1 ≤ (f1e + f2e) / (f1e - f2e) ≤ 2.0. By controlling the relationship between the effective focal length of the first lens and the effective focal length of the second lens, the optical power of the two lenses in the second optical system can be reasonably distributed, which is beneficial to correcting the aberration of the visual optical system.

[0057] In an exemplary embodiment, the radius of curvature R1e of the first side surface of the first lens and the radius of curvature R2e of the second side surface of the first lens may satisfy: -1.95 < (R1e - R2e) / (R1e + R2e) < 1.05. By controlling the relationship between the radius of curvature of the first side surface of the first lens and the radius of curvature of the second side surface of the first lens, it is beneficial to constrain the shape of the first lens, thereby controlling the optical power of the first lens and making it a positive optical power, reducing the object distance of the second optical system, and achieving the macro effect of the second optical system.

[0058] In an exemplary embodiment, the effective focal length f1e of the first lens and the radius of curvature R1e of the first side surface of the first lens may satisfy: 0 < f1e / |R1e| < 1.8. By reasonably configuring the ratio of the effective focal length of the first lens to the radius of curvature of the first side surface of the first lens, the shape of the first lens can be constrained, which is beneficial to the forming process of the first lens.

[0059] In an exemplary embodiment, the total effective focal length f of the visual optical system, the refractive index N1e of the first lens, and the refractive index N1m of the first lens element may satisfy: 0.5 mm < f×(N1e / N1m) < 0.75 mm. By controlling the relationship between the total effective focal length of the visual optical system, the refractive index of the first lens, and the refractive index of the first lens element, the total effective focal length of the visual optical system can be made smaller, the field of view angle of the visual optical system can be increased, and it is convenient for the visual optical system to capture more eye features during eye movement tracking.

[0060] In an exemplary embodiment, the central thickness CT1m of the first lens on the first optical axis, the central thickness CTR of the reflective polarizing element on the first optical axis, the central thickness CTQ of the quarter-wave plate on the first optical axis, and the total effective focal length f of the visual optical system may satisfy: 18.85 < (CT1m + CTR + CTQ) / f < 24.4. By controlling the relationship between the central thickness of the first lens on the first optical axis, the central thickness of the reflective polarizing element on the first optical axis, the central thickness of the quarter-wave plate on the first optical axis, and the total effective focal length of the visual optical system, it is possible to ensure that the first optical system has a reasonable overall body length, increase the optical path when light is refracted and reflected in the first optical system, and is also conducive to miniaturizing the first optical system.

[0061] In an exemplary embodiment, the total effective focal length f of the visual optical system and the effective focal length f1e of the first lens may satisfy: 0.15 < f / f1e < 1.35. By reasonably configuring the ratio of the total effective focal length of the visual optical system to the effective focal length of the first lens, the optical power of the first lens can be made smaller, which is conducive to reasonably distributing the optical powers of the two lenses in the second optical system, thereby improving the imaging quality of the second optical system.

[0062] In an exemplary embodiment, the combined focal length f12e of the first lens and the second lens, the combined focal length fzm of the reflective polarizing element, the quarter-wave plate, and the first lens, and the curvature radius R2m of the second side of the first lens may satisfy: -4.25 mm < f12e × (fzm / R2m) < -3.25 mm. By controlling the above conditional expression, the curvature radius of the second side of the first lens can be made negative, and the total effective focal length of the first optical system can be made greater than the curvature radius of the second side of the first lens, effectively constraining the shape of the second side of the first lens, and controlling the deflection angle of light in the first lens reasonably, reducing the angular effect of the reflective polarizing element and the quarter-wave plate.

[0063] In an exemplary embodiment, the combined focal length f12e of the first lens and the second lens, the effective focal length f1m of the first lens, and the central thickness CT1m of the first lens on the first optical axis may satisfy: 12.3 mm < f12e × (f1m / CT1m) < 15.95 mm. By controlling the relationship between the combined focal length of the first lens and the second lens, the effective focal length of the first lens, and the central thickness of the first lens on the first optical axis, the effective focal length and the central thickness of the first lens can be effectively balanced, indirectly constraining the shape of the first lens, which is conducive to the molding of the first lens.

[0064] In an exemplary embodiment, the center thickness CT1e of the first lens on the second optical axis, the center thickness CT2e of the second lens on the second optical axis, and the total effective focal length f of the visual optical system may satisfy: 0.45<(CT1e+CT2e) / f<1.35. By controlling the relationship between the center thickness of the first lens on the second optical axis, the center thickness of the second lens on the second optical axis, and the total effective focal length of the visual optical system, it is beneficial to constrain the center thickness of the first lens and the second lens, thereby effectively constraining the length of the second optical system and realizing miniaturization of the visual optical system.

[0065] In an exemplary embodiment, the total effective focal length f of the visual optical system, the Abbe number V2e of the second lens and the Abbe number V1e of the first lens may satisfy: 0.5 mm <f×(V2e / V1e)<0.7mm。通过控制上述条件式,能够使得第一透镜的阿贝数与第二透镜的阿贝数相近,例如,第一透镜和第二透镜均采用低折射率材料,降低了第二光学系统的生产成本。

[0066] In an exemplary embodiment, the distance TDe from the first side surface of the first lens to the second side surface of the second lens on the second optical axis, the center thickness CTR of the reflective polarizing element on the first optical axis, and the center thickness CTQ of the quarter wave plate on the first optical axis may satisfy: 1.8 <TDe / (CTR+CTQ)<4.45。通过控制上述条件式,能够有效约束第二光学系统的长度,减小第二光学系统的体积,增大第二光学系统内置于第一光学系统的第二侧的可能性。

[0067] In an exemplary embodiment, the combined focal length f12e of the first lens and the second lens and the center thickness CTQ of the quarter wave plate on the first optical axis may satisfy: 5.65 <f12e / CTQ<7.4。合理配置第一透镜和第二透镜的组合焦距与四分之一波板在第一光轴上的中心厚度的比值,能够使得四分之一波板的厚度较薄,有效避免四分之一波板在拉伸时所导致的相位延迟不均匀的风险,并且有利于曲面贴膜工艺。

[0068] The second aspect of the present application provides a visual optical system which sequentially includes a first optical system and a second optical system from the first side to the second side. The first optical system sequentially includes a reflective polarizing element, a quarter-wave plate, and a first lens along the first optical axis from the first side to the second side; wherein, the first lens has a positive optical power, its first side is concave, and its second side is convex. The second optical system sequentially includes a first lens with a positive optical power and a second lens with an optical power along the second optical axis from the first side to the second side; wherein, the first side of the second lens is concave. The number of lenses with optical power in the second optical system is two.

[0069] The combined focal length f12e of the first lens and the second lens, the combined focal length fzm of the reflective polarizing element, the quarter-wave plate, and the first lens, and the radius of curvature R2m of the second side of the first lens can satisfy: -4.25mm < f12e×(fzm / R2m) < -3.25mm. The visual optical system provided by the present application is configured in a structural form of the combination of the first optical system and the second optical system. The first optical system includes the first lens, the reflective polarizing element, and the quarter-wave plate, and the second optical system includes two lenses and is a macro system. The second optical system has a larger depth of field range. By arranging the first optical system on the first side of the second optical system, it is beneficial to reduce the loss of the overall optical performance of the visual optical system. In addition, by constraining f12e×(fzm / R2m) within a reasonable range, the radius of curvature of the second side of the first lens can be made negative, and the total effective focal length of the first optical system can be made greater than the radius of curvature of the second side of the first lens, effectively constraining the shape of the second side of the first lens, and controlling the deflection angle of the light rays on the first lens reasonably, reducing the angular effect of the reflective polarizing element and the quarter-wave plate.

[0070] Those skilled in the art should understand that without departing from the technical solutions claimed in the present application, the number of lenses and spacer elements constituting the visual optical system can be changed to obtain the various results and advantages described in this specification.

[0071] The following further describes specific embodiments of the visual optical system applicable to the above embodiments with reference to the accompanying drawings.

[0072] Example 1

[0073] The following refers to Figures 1 to 3 Describe the visual optical system according to Embodiment 1 of the present application. Figure 1 The structural schematic diagram of the visual optical system of Embodiment 1 is shown. Figure 2 The structural schematic diagram of the second optical system of Embodiment 1 is shown. Figure 3 The modulation transfer function curve of the visual optical system of Embodiment 1 is shown.

[0074] As Figure 1 and Figure 2 shown, the visual optical system may sequentially include a first optical system 100 and a second optical system 200 from the first side to the second side. The second optical system 200 is located on the side away from the human eye of the first optical system 100. The first optical system 100 sequentially includes a reflective polarizing element RP, a quarter-wave plate QWP, and a first lens L1 along the first optical axis from the near-eye side to the far-eye side. The second optical system 200 sequentially includes a first lens E1 and a second lens E2 along the second optical axis from the near-eye side to the far-eye side. An aperture STO may be disposed between the first optical system 100 and the first lens E1.

[0075] Among them, the first lens L1 has a positive optical power. Its near-eye side surface S1' is concave, and its far-eye side surface S2' is convex. The quarter-wave plate QWP has a near-eye side surface and a far-eye side surface. The far-eye side of the quarter-wave plate QWP is attached to the near-eye side S1' of the first lens L1. The reflective polarizing element RP has a near-eye side surface and a far-eye side surface. The far-eye side of the reflective polarizing element RP is attached to the near-eye side of the quarter-wave plate QWP.

[0076] Among them, the first lens E1 has a positive optical power. Its near-eye side surface S1 is concave, and its far-eye side surface S2 is convex. The second lens E2 has a positive optical power. Its near-eye side surface S3 is concave, and its far-eye side surface is convex. A filter E3 and a protective glass E4 may also be disposed between the image plane S9 and the far-eye side surface S4 of the second lens E2. Light from the object sequentially passes through the surfaces S1', S2', and S1 to S8 and finally forms an image on the imaging plane S9.

[0077] Table 1 shows the basic parameter table of the visual optical system of Example 1. Among them, the unit of the radius of curvature and the thickness / distance is millimeter (mm).

[0078]

[0079]

[0080] Table 1

[0081] In this embodiment, the near-eye side surfaces and the far-eye side surfaces of the first lens L1, the first lens E1, and the second lens E2 are all aspherical surfaces. The surface profile x of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

[0082]

[0083] Wherein, when the aspherical surface is at a position with a height of h along the optical axis direction, x is the sagitta, which is the distance from the vertex of the aspherical surface; c is the paraxial curvature of the aspherical surface, c = 1 / R (that is, 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 correction coefficient of the i-th order of the aspherical surface. Table 2 gives the higher-order term coefficients A4, A6, A8, A 10 、A 12 、A 14 、A 16 、A 18 and A 20 .

[0084] Surface number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1' 5.6060E-06 -2.0180E-09 9.8075E-13 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S2' -4.9740E-06 5.1765E-09 -2.9203E-12 1.4943E-15 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S1 -7.8580E+00 1.6121E+02 -1.3879E+04 2.2959E+05 3.6784E-05 -6.6633E-07 -1.1798E-04 -5.2216E-04 -1.9742E-03 S2 6.2031E+00 -1.2107E+02 3.4479E+03 -4.2601E+04 1.0124E+04 3.8942E+04 -7.8664E-04 -3.0515E-03 -6.6349E-03 S3 9.3031E+00 1.6968E+02 -3.3526E+03 1.8888E+04 -1.3875E+03 6.5600E+04 2.1805E+05 -7.7689E+05 -1.2665E+06 S4 3.8727E+00 -6.4950E-01 2.1314E+02 -1.8730E+03 -1.0831E+03 9.5778E+03 2.0199E+05 7.1793E+05 -7.7408E+06

[0085] Table 2

[0086] Example 2

[0087] The visual optical system according to Embodiment 2 of the present application will be described below with reference to Figures 4 to 6 . Figure 4 FIG. shows a schematic structural diagram of the visual optical system of Embodiment 2. Figure 5 FIG. shows a schematic structural diagram of the second optical system of Embodiment 2. Figure 6 FIG. shows the modulation transfer function curve of the visual optical system of Embodiment 2.

[0088] As shown in Figure 4 and Figure 5 , the visual optical system may sequentially include a first optical system 100 and a second optical system 200 from the first side to the second side, and the second optical system 200 is located on the side away from the human eye of the first optical system 100. The first optical system 100 sequentially includes a reflective polarizing element RP, a quarter-wave plate QWP, and a first lens L1 along the first optical axis from the side close to the human eye to the side far from the human eye. The second optical system 200 sequentially includes a first lens E1 and a second lens E2 along the second optical axis from the side close to the human eye to the side far from the human eye. The aperture stop STO may be disposed between the first optical system 100 and the first lens E1.

[0089] Wherein, the first lens L1 has a positive optical power, its side S1' close to the human eye is concave, and its side S2' far from the human eye is convex. The quarter-wave plate QWP has a side close to the human eye and a side far from the human eye, and the side far from the human eye of the quarter-wave plate QWP is attached to the side S1' close to the human eye of the first lens L1. The reflective polarizing element RP has a side close to the human eye and a side far from the human eye, and the side far from the human eye of the reflective polarizing element RP is attached to the side close to the human eye of the quarter-wave plate QWP.

[0090] Among them, the first lens E1 has a positive optical power, its side S1 close to the human eye is a convex surface, and its side S2 far from the human eye is a convex surface. The second lens E2 has a positive optical power, its side S3 close to the human eye is a concave surface, and its side far from the human eye is a convex surface. A filter E3 and a protective glass E4 can also be arranged between the image plane S9 and the side S4 of the second lens E2 far from the human eye. The light from the object sequentially passes through the surfaces S1', S2' and S1 to S8 and finally forms an image on the imaging plane S9.

[0091] Table 3 shows the basic parameter table of the visual optical system of Embodiment 2, where the units of the radius of curvature and the thickness / distance are both millimeters (mm).

[0092]

[0093] Table 3

[0094] In this embodiment, the sides of the first lens L1, the first lens E1 and the second lens E2 close to and far from the human eye are all aspherical surfaces. Table 4 gives the higher-order term coefficients A4, A6, A8, A 10 , A 12 , A 14 , A 16 , A 18 and A 20 that can be used for the aspherical surfaces S1', S2', S1, S2, S3, S4 in Embodiment 2.

[0095] Surface number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1' 5.6060E-06 -2.0180E-09 9.8075E-13 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S2' -4.9740E-06 5.1765E-09 -2.9203E-12 1.4943E-15 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S1 -4.2261E+00 -4.4694E+00 -1.2195E+03 1.0956E+04 3.6784E-05 -6.6633E-07 -1.1798E-04 -5.2216E-04 -1.9742E-03 S2 2.4224E+00 -1.4599E+01 2.1445E+02 -1.9828E+03 1.0124E+04 3.8942E+04 -7.8664E-04 -3.0515E-03 -6.6349E-03 S3 7.7568E+00 5.2458E+01 -5.5925E+01 -5.5733E+02 -1.3875E+03 6.5600E+04 2.1805E+05 -7.7689E+05 -1.2665E+06 S4 3.0262E+00 -1.6421E+00 3.0853E+02 -1.7374E+03 -1.0831E+03 9.5778E+03 2.0199E+05 7.1793E+05 -7.7408E+06

[0096] Table 4

[0097] Example 3

[0098] The following refers to Figures 7 to 9 to describe the visual optical system according to Embodiment 3 of the present application. Figure 7 Fig. shows the structural schematic diagram of the visual optical system of Embodiment 3. Figure 8 Fig. shows the structural schematic diagram of the second optical system of Embodiment 3. Figure 9 Fig. shows the modulation transfer function curve of the visual optical system of Embodiment 3.

[0099] As Figure 7 and Figure 8As shown, the visual optical system may sequentially include a first optical system 100 and a second optical system 200 from the first side to the second side, and the second optical system 200 is located on the side of the first optical system 100 away from the human eye. The first optical system 100 sequentially includes a reflective polarizing element RP, a quarter-wave plate QWP, and a first lens L1 along the first optical axis from the near-eye side to the far-eye side. The second optical system 200 sequentially includes a first lens E1 and a second lens E2 along the second optical axis from the near-eye side to the far-eye side. An aperture STO may be disposed between the first optical system 100 and the first lens E1.

[0100] Among them, the first lens L1 has a positive optical power, its near-eye side surface S1' is concave, and its far-eye side surface S2' is convex. The quarter-wave plate QWP has a near-eye side surface and a far-eye side surface, and the far-eye side of the quarter-wave plate QWP is attached to the near-eye side S1' of the first lens L1. The reflective polarizing element RP has a near-eye side surface and a far-eye side surface, and the far-eye side of the reflective polarizing element RP is attached to the near-eye side of the quarter-wave plate QWP.

[0101] Among them, the first lens E1 has a positive optical power, its near-eye side surface S1 is convex, and its far-eye side surface S2 is convex. The second lens E2 has a positive optical power, its near-eye side surface S3 is concave, and its far-eye side surface is convex. A filter E3 and a protective glass E4 may also be disposed between the image plane S9 and the far-eye side surface S4 of the second lens E2. The light from the object sequentially passes through the surfaces S1', S2', and S1 to S8 and finally forms an image on the imaging plane S9.

[0102] Table 5 shows the basic parameter table of the visual optical system of Embodiment 3, where the units of the radius of curvature and the thickness / distance are both millimeters (mm).

[0103]

[0104] Table 5

[0105] In this embodiment, the near-eye side surfaces and the far-eye side surfaces of the first lens L1, the first lens E1, and the second lens E2 are all aspherical surfaces, and Table 6 gives the high-order term coefficients A4, A6, A8, A 10 , A 12 , A 14 , A 16 , A 18 and A 20 that can be used for the aspherical surfaces S1', S2', S1, S2, S3, and S4 in Embodiment 3.

[0106]

[0107]

[0108] Table 6

[0109] Example 4

[0110] The following refers to Figures 10 to 12 Describe the visual optical system according to Embodiment 4 of the present application. Figure 10 Fig. shows a schematic structural diagram of the visual optical system of Embodiment 4. Figure 11 Fig. shows a schematic structural diagram of the second optical system of Embodiment 4. Figure 12 Fig. shows the modulation transfer function curve of the visual optical system of Embodiment 4.

[0111] As Figure 10 and Figure 11 shown, the visual optical system may sequentially include a first optical system 100 and a second optical system 200 from the first side to the second side, and the second optical system 200 is located on the side of the first optical system 100 away from the human eye. The first optical system 100 sequentially includes a reflective polarizing element RP, a quarter-wave plate QWP, and a first lens L1 along the first optical axis from the near-eye side to the far-eye side. The second optical system 200 sequentially includes a first lens E1 and a second lens E2 along the second optical axis from the near-eye side to the far-eye side. The aperture stop STO may be disposed between the first optical system 100 and the first lens E1.

[0112] Among them, the first lens L1 has a positive optical power, its near-eye side surface S1' is concave, and its far-eye side surface S2' is convex. The quarter-wave plate QWP has a near-eye side surface and a far-eye side surface, and the far-eye side of the quarter-wave plate QWP is attached to the near-eye side S1' of the first lens L1. The reflective polarizing element RP has a near-eye side surface and a far-eye side surface, and the far-eye side of the reflective polarizing element RP is attached to the near-eye side of the quarter-wave plate QWP.

[0113] Among them, the first lens E1 has a positive optical power, its near-eye side surface S1 is convex, and its far-eye side surface S2 is concave. The second lens E2 has a positive optical power, its near-eye side surface S3 is concave, and its far-eye side surface is convex. A filter E3 and a protective glass E4 may also be disposed between the image plane S9 and the far-eye side surface S4 of the second lens E2. The light from the object sequentially passes through the respective surfaces S1', S2', and S1 to S8 and finally forms an image on the imaging plane S9.

[0114] Table 7 shows the basic parameter table of the visual optical system of Embodiment 4, where the unit of the radius of curvature and the thickness / distance is millimeter (mm).

[0115]

[0116]

[0117] Table 7

[0118] In this embodiment, both the near-eye side and the far-eye side of the first lens L1, the first lens E1, and the second lens E2 are aspherical surfaces. Table 8 gives the higher-order coefficients A4, A6, A8, A 10 , A 12 , A 14 , A 16 , A 18 , and A 20 for each of the aspherical surfaces S1', S2', S1, S2, S3, and S4 that can be used in Example 4.

[0119] Surface number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1' 5.6060E-06 -2.0180E-09 9.8075E-13 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S2' -4.9740E-06 5.1765E-09 -2.9203E-12 1.4943E-15 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S1 2.8185E+00 3.7013E+02 -5.6960E+03 -1.2868E+05 3.6784E-05 -6.6633E-07 -1.1798E-04 -5.2216E-04 -1.9742E-03 S2 1.2511E+01 3.3384E+02 8.7627E+03 -2.0431E+05 1.0124E+04 3.8942E+04 -7.8664E-04 -3.0515E-03 -6.6349E-03 S3 -2.5049E+00 1.0372E+02 -1.7054E+03 5.7616E+04 -1.3875E+03 6.5600E+04 2.1805E+05 -7.7689E+05 -1.2665E+06 S4 -3.8379E-01 -2.8105E+01 3.8987E+02 -7.2573E+03 -1.0831E+03 9.5778E+03 2.0199E+05 7.1793E+05 -7.7408E+06

[0120] Table 8

[0121] Example 5

[0122] The following refers to Figures 13 to 15 to describe the visual optical system according to Embodiment 5 of the present application. Figure 13 FIG. shows a schematic structural diagram of the visual optical system of Embodiment 5. Figure 14 FIG. shows a schematic structural diagram of the second optical system of Embodiment 5. Figure 15 FIG. shows the modulation transfer function curve of the visual optical system of Embodiment 5.

[0123] As shown in Figure 13 and Figure 14 , the visual optical system may sequentially include a first optical system 100 and a second optical system 200 from the first side to the second side. The second optical system 200 is located on the side away from the human eye of the first optical system 100. The first optical system 100 sequentially includes a reflective polarizing element RP, a quarter-wave plate QWP, and a first lens L1 along the first optical axis from the near-eye side to the far-eye side. The second optical system 200 sequentially includes a first lens E1 and a second lens E2 along the second optical axis from the near-eye side to the far-eye side. The aperture stop STO may be disposed between the first optical system 100 and the first lens E1.

[0124] Among them, the first lens L1 has a positive optical power. Its near-eye side S1' is a concave surface, and its far-eye side S2' is a convex surface. The quarter-wave plate QWP has a near-eye side and a far-eye side. The far-eye side of the quarter-wave plate QWP is attached to the near-eye side S1' of the first lens L1. The reflective polarizing element RP has a near-eye side and a far-eye side. The far-eye side of the reflective polarizing element RP is attached to the near-eye side of the quarter-wave plate QWP.

[0125] Among them, the first lens E1 has a positive optical power. Its side S1 close to the human eye is concave, and its side S2 far from the human eye is convex. The second lens E2 has a negative optical power. Its side S3 close to the human eye is concave, and its side far from the human eye is concave. A filter E3 and a protective glass E4 can also be provided between the image plane S9 and the side S4 of the second lens E2 far from the human eye. The light from the object sequentially passes through the surfaces S1', S2' and S1 to S8 and finally forms an image on the imaging plane S9.

[0126] Table 9 shows the basic parameter table of the visual optical system of Example 5, where the unit of the radius of curvature and the thickness / distance is millimeter (mm).

[0127]

[0128]

[0129] Table 9

[0130] In this embodiment, the sides of the first lens L1, the first lens E1 and the second lens E2 close to the human eye and far from the human eye are all aspherical surfaces. Table 10 gives the higher-order coefficients A4, A6, A8, A 10 、A 12 、A 14 、A 16 、A 18 and A 20 .

[0131] Surface number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1' 5.6060E-06 -2.0180E-09 9.8075E-13 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S2' -4.9740E-06 5.1765E-09 -2.9203E-12 1.4943E-15 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S1 6.8151E-02 1.0692E+02 -3.3942E+03 1.1144E+05 3.6784E-05 -6.6633E-07 -1.1798E-04 -5.2216E-04 -1.9742E-03 S2 1.2273E+01 -1.2001E+02 1.1098E+03 -5.6976E+03 1.0124E+04 3.8942E+04 -7.8664E-04 -3.0515E-03 -6.6349E-03 S3 1.0775E+01 -1.6123E+02 1.3572E+03 -6.2006E+03 -1.3875E+03 6.5600E+04 2.1805E+05 -7.7689E+05 -1.2665E+06 S4 -9.8310E-01 -4.3723E+01 4.5106E+02 -2.2274E+03 -1.0831E+03 9.5778E+03 2.0199E+05 7.1793E+05 -7.7408E+06

[0132] Table 10

[0133] Table 11 shows the values of the parameters f, f1m, fzm, f1e, f2e and f12e of each embodiment in Embodiments 1-5.

[0134] Example parameters 1 2 3 4 5 f (mm) 0.63 0.69 0.56 0.54 0.57 f1m (mm) 277.87 277.87 277.87 277.87 277.87 fzm (mm) 277.05 277.05 277.05 277.05 277.05 f1e (mm) 0.48 0.53 2.13 3.00 0.45 f2e (mm) 14.81 10.76 0.71 0.62 -2.05 f12e (mm) 0.67 0.74 0.60 0.57 0.60

[0135] Table 11

[0136] Table 12 shows the values of the conditional expressions of each embodiment in Embodiments 1-5.

[0137]

[0138]

[0139] Table 12

[0140] The above description is only a preferred embodiment of the present application and an explanation of the technical principles applied. Those skilled in the art should understand that the scope of the application involved in the present application is not limited to the technical solutions formed by the 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 application concept. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) disclosed in the present application that have similar functions.

Claims

1. A visual optical system, characterized in that, It includes a first optical system and a second optical system in sequence from the first side to the second side; The first optical system includes a reflective polarizing element, a quarter-wave plate, and a first lens in sequence along a first optical axis from the first side to the second side; wherein, the first lens has a positive optical power, its first side is concave, and its second side is convex; The second optical system includes a first lens with a positive optical power and a second lens with an optical power in sequence along a second optical axis from the first side to the second side; wherein, the first side of the second lens is concave; The number of lenses with optical power in the second optical system is two; The radius of curvature R1m of the first side of the first lens, the radius of curvature R2m of the second side of the first lens, the combined focal length f12e of the first lens and the second lens, and the distance TDe on the second optical axis from the first side of the first lens to the second side of the second lens satisfy: 0.8 < (R1m / R2m) / (f12e / TDe) < 2.

0.

2. The visual optical system according to claim 1, wherein, The central thickness CT2e of the second lens on the second optical axis and the radius of curvature R3e of the first side of the second lens satisfy: -1.25 < CT2e / R3e < -0.

15.

3. The visual optical system according to claim 1, characterized in that, The effective focal length f1e of the first lens and the effective focal length f2e of the second lens satisfy: -1.1 ≤ (f1e + f2e) / (f1e - f2e) ≤ 2.

0.

4. The visual optical system according to claim 1, wherein The radius of curvature R1e of the first side of the first lens and the radius of curvature R2e of the second side of the first lens satisfy: -1.95 < (R1e - R2e) / (R1e + R2e) < 1.

05.

5. The visual optical system according to claim 1, characterized in that, The effective focal length f1e of the first lens and the radius of curvature R1e of the first side of the first lens satisfy: 0 < f1e / |R1e| < 1.

8.

6. The visual optical system according to any one of claims 1 to 5, characterized in that The total effective focal length f of the visual optical system, the refractive index N1e of the first lens, and the refractive index N1m of the first lens satisfy: 0.5 mm < f×(N1e / N1m) < 0.75 mm.

7. The visual optical system according to any one of claims 1 to 5, characterized in that, The central thickness CT1m of the first lens on the first optical axis, the central thickness CTR of the reflective polarizing element on the first optical axis, the central thickness CTQ of the quarter-wave plate on the first optical axis, and the total effective focal length f of the visual optical system satisfy: 18.85 < (CT1m + CTR + CTQ) / f < 24.

4.

8. The visual optical system according to any one of claims 1 to 5, characterized in that, The total effective focal length f of the visual optical system and the effective focal length f1e of the first lens satisfy: 0.15 < f / f1e < 1.

35.

9. The visual optical system according to any one of claims 1 to 5, characterized in that, The combined focal length f12e of the first lens and the second lens, the combined focal length fzm of the reflective polarizing element, the quarter-wave plate, and the first lens, and the radius of curvature R2m of the second side of the first lens satisfy: -4.25 mm < f12e×(fzm / R2m) < -3.25 mm.

10. The visual optical system according to any one of claims 1 to 5, characterized in that, The combined focal length f12e of the first lens and the second lens, the effective focal length f1m of the first lens, and the central thickness CTR1m of the first lens on the first optical axis satisfy: 12.3 mm < f12e × (f1m / CTR1m) < 15.95 mm.

11. The visual optical system according to any one of claims 1 to 5, characterized in that, The central thickness CTR1e of the first lens on the second optical axis, the central thickness CTR2e of the second lens on the second optical axis, and the total effective focal length f of the visual optical system satisfy: 0.45 < (CTR1e + CTR2e) / f < 1.

35.

12. The visual optical system according to any one of claims 1 to 5, characterized in that, The total effective focal length f of the visual optical system, the Abbe number V2e of the second lens, and the Abbe number V1e of the first lens satisfy: 0.5 mm < f × (V2e / V1e) < 0.7 mm.

13. The visual optical system according to any one of claims 1 to 5, characterized in that, The distance TDe on the second optical axis from the first side surface of the first lens to the second side surface of the second lens, the central thickness CTR of the reflective polarizing element on the first optical axis, and the central thickness CTQ of the quarter-wave plate on the first optical axis satisfy: 1.8 < TDe / (CTR + CTQ) < 4.

45.

14. The visual optical system according to any one of claims 1 to 5, characterized in that, The combined focal length f12e of the first lens and the second lens and the central thickness CTQ of the quarter-wave plate on the first optical axis satisfy: 5.65 < f12e / CTQ < 7.

4.

15. The visual optical system according to any one of claims 1 to 5, characterized in that, The angle θ between the second optical axis and the first optical axis satisfies: 0° < θ < 90°.

Images