Visual optical system

Abstract

The embodiment of the utility model discloses a visual optical system which comprises a first optical system and a second optical system, and the first optical system sequentially comprises a first element group, a second element group and a third element group from a near-eye side to a display side along a first optical axis, the first element group comprises a first lens, a reflective polarizing element and a quarter-wave plate; the second element group comprises a second lens; the third element group comprises a third lens; the second optical system sequentially comprises a first lens with focal power, a second lens with positive focal power, a third lens with positive focal power and a fourth lens with focal power from the first side to the second side along the second optical axis; wherein the distance TDm from the first side surface of the first element group to the second side surface of the third element group on the first optical axis and the distance TDe from the first surface of the first lens to the second surface of the fourth lens on the second optical axis satisfy 5.0 lt; tD < m > / TD < solid >; 15.0, 15.0).

Description

Technical Field

[0001] The present application relates to the field of optical elements, and in particular, to a visual optical system. Background Art

[0002] VR (Virtual Reality) technology creates a realistic simulated environment, allowing users to immerse themselves in different environments, bringing about tremendous changes in social, entertainment, medical, and education fields.

[0003] With the continuous development of VR technology, consumers have an increasing demand for VR interactive experience. However, due to the limited storage space and computing power of VR hardware, it is difficult to achieve consumer demand. Among them, in order to solve the screen window feeling caused by insufficient resolution of LCD (Liquid Crystal Display) screens, higher resolution LCD screens or Micro_OLED (Micro Organic Lighting Emitting Display) screens are required, but the increase in resolution also means that more storage space and computing power are needed. In order to solve the problem of insufficient computing power, the display screen can be partially rendered, and the premise of local rendering is the Eye Tracking function. At present, the Eye Tracking Camera (eye tracking system) is usually placed on the bracket near the eye end of the VR device, which is visible to the eye, and thus will affect the aesthetics of the VR device product. Utility Model Content

[0004] According to an embodiment of the present application, a visual optical system is provided, including a first optical system and a second optical system, wherein the first optical system includes, in sequence from the near-eye side to the display side, a first element group, a second element group and a third element group along a first optical axis, wherein the first element group includes a first lens, a reflective polarizing element and a quarter-wave plate; the second element group includes a second lens; the third element group includes a third lens; the second optical system includes, in sequence from the first side to the second side, a first lens with optical power, a second lens with positive optical power, a third lens with positive optical power and a fourth lens with optical power along a second optical axis; wherein a distance TDm from the first side surface of the first element group to the second side surface of the third element group on the first optical axis and a distance TDe from the first surface of the first lens to the second surface of the fourth lens on the second optical axis satisfy: 5.0 <TDm / TDe<15.0。

[0005] In one or more embodiments, the focal length f1m of the first element group and the focal length f3m of the third element group satisfy: 0.3 <f1m / f3m<2.5。

[0006] In one or more embodiments, the distance TDm on the first optical axis from the first side surface of the first element group to the second side surface of the third element group satisfies -0.01 < TDm / f3m < 0.50 with the focal length f3m of the third element group.

[0007] In one or more embodiments, the distance TDm on the first optical axis from the first side surface of the first element group to the second side surface of the third element group satisfies 0.1 < CT3m / TDm < 0.9 with the central thickness CT3m of the third lens on the first optical axis.

[0008] In one or more embodiments, the refractive index N1m of the first lens, the refractive index N2m of the second lens, the air gap T12m between the first element group and the second element group on the first optical axis, the focal length f1m of the first element group, and the focal length f2m of the second element group satisfy -3.5 < (N1m + N2m)*T12m / (f2m / f1m) < 2.0.

[0009] In one or more embodiments, the refractive index N3m of the third lens satisfies 0.8 < N3m / N1e < 1.20 with the refractive index N1e of the first lens; the dispersion coefficient V3m of the third lens satisfies 0 < |V3m - V1e| < 40.0 with the dispersion coefficient V1e of the first lens.

[0010] In one or more embodiments, the distance TTLe on the second optical axis from the first surface of the first lens to the imaging surface satisfies 1.30 < TTLe / TDe < 1.80 with the distance TDe on the second optical axis from the first surface of the first lens to the second surface of the fourth lens.

[0011] In one or more embodiments, the refractive index N2e of the second lens, the refractive index N3e of the third lens, the central thickness CT2e of the second lens on the second optical axis, and the central thickness CT3e of the third lens on the second optical axis satisfy 0.2 < (N2e*CT2e) / (N3e*CT3e) < 1.8.

[0012] In one or more embodiments, the focal length f1e of the first lens satisfies -1.50 < f1e / f2e < 0.09 with the focal length f2e of the second lens.

[0013] In one or more embodiments, the focal length f3e of the third lens satisfies 0.01 < |f3e / f4e| < 1.20 with the focal length f4e of the fourth lens.

[0014] In one or more embodiments, the radius of curvature R1m of the first side surface of the first lens satisfies 0 < R1m / R3m < 1.0 with the radius of curvature R3m of the first side surface of the second lens.

[0015] In one or more embodiments, the radius of curvature R5m of the first side surface of the third lens and the radius of curvature R6m of the second side surface of the third lens satisfy: -2.0 <R6m / R5m<2.0。

[0016] In one or more embodiments, a curvature radius R1e of the first surface of the first lens and a curvature radius R8e of the second surface of the fourth lens satisfy: -5.0<|R8e| / R1e<0.

[0017] In one or more embodiments, the focal length f3e of the third lens, the curvature radius R5e of the first surface of the third lens, and the curvature radius R6e of the second surface of the third lens satisfy: -2.0 <f3e / (R5e+R6e)<0。

[0018] In one or more embodiments, the total focal length f of the visual optical system satisfies: 0.8 <f<1.5。

[0019] In one or more embodiments, the second optical system is disposed between the first optical system and the display side, the first side of the second optical system is relatively close to the near-eye side, and the second side of the second optical system is relatively close to the display side.

[0020] In one or more embodiments, an angle θ between the second optical axis and the first optical axis satisfies: 0°<θ<90°.

[0021] In one or more embodiments, the second optical system further includes an aperture, which is disposed on one side of the first surface of the first lens; the spacing distance Tz from the intersection of the second side surface of the element group closest to the display side in the first optical system and the first optical axis to the intersection of the aperture center of the second optical system and the second optical axis along the first optical axis direction satisfies: 0 mm <Tz<15.0mm。

[0022] In one or more embodiments, the second optical system further includes an aperture, which is disposed on one side of the first surface of the first lens; the spacing distance Ty between the intersection of the second side surface of the element group closest to the display side in the first optical system and the first optical axis and the intersection of the aperture center of the second optical system and the second optical axis along the direction perpendicular to the first optical axis satisfies: 5 mm <Ty<25.0mm。

[0023] In one or more embodiments, the second side surface of the first lens is at least partially bonded to the reflective polarizing element, and the second side surface of the reflective polarizing element is at least partially bonded to the quarter-wave plate; the second side surface of the first lens is a plane.

[0024] The visual optical system provided according to the embodiment of the present application may include a first optical system and a second optical system. The first optical system uses a reflective polarizing element and a quarter-wave plate to realize light path reversal, wherein the quarter-wave plate can change the polarization state of polarized light, so that circularly polarized light becomes s-light or p-light, and the reflective polarizing element can transmit or reflect s-light or p-light, thereby reversing the light path and reducing the total length of the near-eye display system; the second optical system can form an eye tracking system with the first optical system. By controlling the ratio of the on-axis length of the first optical system to the on-axis length of the second optical system, the miniaturization of the second optical system can be well controlled, which is beneficial to make it invisible to the eye while ensuring the eye tracking function, thereby improving the practicality and aesthetics of the VR device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0026] Figure 1 A schematic structural diagram of a visual optical system according to an exemplary embodiment of the present application is shown;

[0027] Figure 2 Shows Figure 1 An enlarged schematic diagram of the second optical system in the visual optical system;

[0028] Figure 3 A schematic structural diagram of a visual optical system according to Embodiment 1 of the present application is shown;

[0029] Figure 4 A schematic diagram of a second optical system of the visual optical system according to the first embodiment of the present application is shown;

[0030] Figure 5 A schematic diagram of an MTF curve of a visual optical system according to Embodiment 1 of the present application is shown;

[0031] Figure 6 A schematic structural diagram of a visual optical system according to Embodiment 2 of the present application is shown;

[0032] Figure 7 A schematic diagram showing a second optical system of the visual optical system according to the second embodiment of the present application is shown;

[0033] Figure 8 A schematic diagram of an MTF curve of a visual optical system according to Embodiment 2 of the present application is shown;

[0034] Fig. 9 A schematic structural diagram of a visual optical system according to Embodiment 3 of the present application is shown;

[0035] Fig.10 A schematic diagram showing a second optical system of the visual optical system according to the third embodiment of the present application is shown;

[0036] Fig.11 A schematic diagram of an MTF curve of a visual optical system according to Embodiment 3 of the present application is shown;

[0037] Fig.12 A schematic structural diagram of a visual optical system according to a fourth embodiment of the present application is shown;

[0038] Fig.13 A schematic diagram showing a second optical system of a visual optical system according to a fourth embodiment of the present application is shown;

[0039] Fig.14 A schematic diagram of the MTF curve of the visual optical system according to the fourth embodiment of the present application is shown. DETAILED DESCRIPTION

[0040] 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.

[0041] It should be noted that in this specification, the expressions of first, second, third, 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 or the first lens.

[0042] 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.

[0043] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface 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 position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region.

[0044] 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.

[0045] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as those 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.

[0046] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following examples only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for those of ordinary skill in the art, without departing from the concept of the present application, several variations and improvements can also be made, which all belong to the protection scope of the present application.

[0047] The features, principles and other aspects of the present application are described in detail below.

[0048] refer to Figure 1 As shown, the visual optical system according to an exemplary embodiment of the present application may include a first optical system and a second optical system.

[0049] In an exemplary embodiment, the first optical system may include a first element group, a second element group, and a third element group arranged in sequence from the first side to the second side along the first optical axis Z1, wherein the first element group may include a first lens, a reflective polarizing element, and a quarter wave plate, the second element group may include a second lens, and the third element group may include a third lens. There may be an air gap between the first element group and the second element group, and between the second element group and the third element group.

[0050] In an exemplary embodiment, the first side may be a near-eye side, and the second side may be a display side. Accordingly, each element group (first element group, second element group, third element group) and each optical element (first lens, reflective polarizing element, quarter-wave plate, second lens, third lens, etc.) in the first optical system may have a first side surface relatively close to the near-eye side and a second side surface relatively close to the display side.

[0051] refer to Figure 2 As shown, in an exemplary embodiment, the second optical system may include a first lens, a second lens, a third lens, and a fourth lens sequentially arranged from the first side to the second side along the second optical axis Z2. An air gap may be provided between adjacent two lenses of the first to fourth lenses.

[0052] In exemplary embodiments, the first lens may have positive or negative power; the second lens may have positive power; the third lens may have positive power; and the fourth lens may have positive or negative power.

[0053] In an exemplary embodiment, the first optical system may be configured as a catadioptric near-eye display system, for example, and the second optical system may be configured as an infrared band imaging system, and the second optical system may form an EyeTracking system with the first optical system.

[0054] Exemplarily, the second optical system can be used to image real scenes, and the real image is transmitted to the display screen in the form of electrical signals; the first optical system is used to project the virtual image on the display screen and the real image transmitted to the display screen, such as projecting it into the user's eyes, so that the user can see a combination of virtual and real images, thereby enhancing the user's sense of immersion.

[0055] Exemplarily, the visual optical system according to the exemplary embodiment of the present application can be used in a variety of virtual reality display devices, such as VR head-mounted devices, or AR (Augmented Reality) electronic devices, etc.

[0056] In an exemplary embodiment, the reflective polarizing element may be disposed on the second side of the first lens and at least partially adhered to the second side of the first lens; the quarter-wave plate may be disposed on the second side of the reflective polarizing element and at least partially adhered to the second side of the reflective polarizing element. The quarter-wave plate may change the polarization state of polarized light, so that circularly polarized light becomes s-light or p-light. When the light passes through the reflective polarizing element, the reflective polarizing element may transmit or reflect the s-light or p-light, thereby refracting the light path and reducing the total length of the near-eye display system.

[0057] In an exemplary embodiment, the first optical system may further include a partial reflection layer, which may be attached to the first side or the second side of the second lens, or the partial reflection layer may be attached to the first side or the second side of the third 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 refracted multiple times, thereby effectively reducing the body length of the first optical system.

[0058] Combined with Figure 1 As shown, in an exemplary embodiment, the second optical system may be disposed between the first optical system and the display side (display screen). The first side of the second optical system is relatively closer to the near-eye side, and the second side of the second optical system is relatively closer to the display side. Thus, the first surfaces of the first lens, the second lens, the third lens, and the fourth lens in the second optical system are relatively closer to the near-eye side, and the second surfaces are relatively closer to the display side. By disposing the second optical system between the first optical system and the display (display screen), without compromising the performance of the first optical system, the eye-tracking function of the second optical system is ensured, and the appearance of the head-mounted device of the virtual reality device is improved, making it visually invisible, thereby enhancing the aesthetics of the product.

[0059] The visual optical system according to an exemplary embodiment of the present application may satisfy 5.0 < TDm / TDe < 15.0, where TDm is the distance from the first side of the first element group to the second side of the third element group on the first optical axis, and TDe is the distance from the first surface of the first lens to the second surface of the fourth lens on the second optical axis. Satisfying 5.0 < TDm / TDe < 15.0 and reasonably controlling the ratio of the on-axis length of the first optical system to the on-axis length of the second optical system can well control the miniaturization of the second optical system, which is beneficial to disposing the second optical system between the first optical system and the screen to make it visually invisible and improve the aesthetics of the product; and it can ensure the eye-tracking function while achieving miniaturization.

[0060] In an exemplary embodiment, the visual optical system may satisfy 0.3 < f1m / f3m < 2.5, where f1m is the focal length of the first element group and f3m is the focal length of the third element group. Satisfying 0.3 < f1m / f3m < 2.5, on the one hand, makes the focal lengths of the two element groups not differ much. In a large-aperture optical system, it indirectly controls the sag heights of the two element groups, which is beneficial to the forming of the two elements; on the other hand, when the focal lengths of the two element groups are both relatively large, it reduces the influence of the aberrations introduced by the two element groups on the second optical system.

[0061] In an exemplary embodiment, the visual optical system may satisfy -0.01 < TDm / f3m < 0.50, where TDm is the distance on the first optical axis from the first side surface of the first element group to the second side surface of the third element group, and f3m is the focal length of the third element group. By satisfying -0.01 < TDm / f3m < 0.50 and controlling the ratio of the distance on the first optical axis from the first side surface of the first element group to the second side surface of the third element group to the focal length of the third element group, TDm can be made smaller, which is beneficial to controlling the mechanical length of the first optical system.

[0062] In an exemplary embodiment, the visual optical system may satisfy 0.1 < CT3m / TDm < 0.9, where TDm is the distance on the first optical axis from the first side surface of the first element group to the second side surface of the third element group, and CT3m is the central thickness of the third lens on the first optical axis. By satisfying 0.1 < CT3m / TDm < 0.9 and controlling the ratio of the on-axis distance from the first side surface of the first element group to the second side surface of the third element group to the central thickness of the third lens, it is beneficial to controlling the thickness of the third lens, thereby increasing the assembly stability.

[0063] In an exemplary embodiment, the visual optical system may satisfy -3.5 < (N1m + N2m)*T12m / (f2m / f1m) < 2.0, where N1m is the refractive index of the first lens, N2m is the refractive index of the second lens, T12m is the spatial interval between the first element group and the second element group on the first optical axis, f1m is the focal length of the first element group, and f2m is the focal length of the second element group. By satisfying -3.5 < (N1m + N2m)*T12 / (f2m / f1m) < 2.0 and controlling the correlation between the refractive indices, focal lengths, and air gap of the first lens in the first element group and the second lens in the second element group, it is beneficial to controlling the incident angle of the reflected light on the second side surface of the first element group, thereby controlling the incident angle of the light on the reflective polarizing element, which is beneficial to improving the reflection efficiency of the reflected light and reducing light leakage.

[0064] In an exemplary embodiment, the visual optical system may satisfy 0.8 < N3m / N1e < 1.20, 0 < |V3m - V1e| < 40.0, where N3m is the refractive index of the third lens, N1e is the refractive index of the first lens, V3m is the dispersion coefficient of the third lens, and V1e is the dispersion coefficient of the first lens. By satisfying 0.8 < N3m / N1e < 1.20, 0 < |V3m - V1e| < 40.0 and controlling the relative relationship between the refractive indices and Abbe numbers of the third lens and the first lens, the material selection of the third lens and the first lens is controlled. The material selection requirements for the third lens are low stress, generally low refractive index and high Abbe number. The first lens, as the first lens of the infrared band imaging system, is generally low refractive index and high Abbe or medium refractive index and medium Abbe number.

[0065] In an exemplary embodiment, the visual optical system may satisfy 1.30 < TTLe / TDe < 1.80, where TTLe is the distance from the first surface of the first lens to the imaging surface on the second optical axis, and TDe is the distance from the first surface of the first lens to the second surface of the fourth lens on the second optical axis. Satisfying 1.30 < TTLe / TDe < 1.80, by controlling the ratio of the distance from the first surface of the first lens to the imaging surface to the distance from the first surface of the first lens to the second surface of the fourth lens, the back focal length of the second optical system can be effectively controlled, which is beneficial to the selection of the thickness of the IR (infrared sensor) chip.

[0066] In an exemplary embodiment, the visual optical system may satisfy 0.2 < (N2e*CT2e) / (N3e*CT3e) < 1.8, where N2e is the refractive index of the second lens, N3e is the refractive index of the third lens, CT2e is the central thickness of the second lens on the second optical axis, and CT3e is the central thickness of the third lens on the second optical axis. Satisfying 0.2 < (N2e*CT2e) / (N3e*CT3e) < 1.8, by controlling the ratio of the refractive index and thickness of the second lens and the third lens, it is beneficial to control the optical power of the second lens and the third lens, thereby facilitating the control of the height of the light rays in the second lens and the third lens, and facilitating the matching of the barrel shape.

[0067] In an exemplary embodiment, the visual optical system may satisfy -1.50 < f1e / f2e < 0.09, where f1e is the focal length of the first lens and f2e is the focal length of the second lens. Satisfying -1.50 < f1e / f2e < 0.09, by controlling the ratio of the focal lengths of the first lens and the second lens, the optical powers of the first lens and the second lens are opposite, and the combination of positive and negative optical powers is adopted, which is beneficial to correcting the system aberration.

[0068] In an exemplary embodiment, the visual optical system may satisfy 0.01 < |f3e / f4e| < 1.20, where f3e is the focal length of the third lens and f4e is the focal length of the fourth lens. Satisfying 0.01 < |f3e / f4e| < 1.20, by controlling the ratio of the focal lengths of the third lens and the fourth lens, the focal length of the fourth lens is greater than that of the third lens, which is beneficial to the compression of the light rays by the fourth lens and reduces the incident angle of the light rays on the imaging surface.

[0069] In an exemplary embodiment, the visual optical system may satisfy 0 < R1m / R3m < 1.0, where R1m is the radius of curvature of the first side surface of the first lens and R3m is the radius of curvature of the first side surface of the second lens. Satisfying 0 < R1m / R3m < 1.0, by controlling the ratio of the radius of curvature of the first side surface of the first lens to the radius of curvature of the first side surface of the second lens, it is beneficial to increase the optical power of the first lens, thereby reducing the height of the light rays on the second lens and the third lens.

[0070] In an exemplary embodiment, the visual optical system may satisfy -2.0 < R6m / R5m < 2.0, where R5m is the radius of curvature of the first side of the third lens, and R6m is the radius of curvature of the second side of the third lens. Satisfying -2.0 < R6m / R5m < 2.0, by controlling the ratio of the radius of curvature of the first side to the second side of the third lens, the shape of the third lens is effectively controlled, especially the second side of the third lens, so that its radius of curvature is smaller. On the one hand, it is beneficial to compress the first reflected light, and on the other hand, it is beneficial to compress the second transmitted light.

[0071] In an exemplary embodiment, the visual optical system may satisfy -5.0 < |R8e| / R1e < 0, where R1e is the radius of curvature of the first surface of the first lens, and R8e is the radius of curvature of the second surface of the fourth lens. Satisfying -5.0 < |R8e| / R1e < 0, by controlling the ratio of the radius of curvature of the first surface of the first lens to the second surface of the fourth lens, and making the radius of curvature of the first surface of the first lens negative, combined with the front position of the aperture, it is beneficial to increase the field of view angle of the optical system.

[0072] In an exemplary embodiment, the visual optical system may satisfy -2.0 < f3e / (R5e + R6e) < 0, where f3e is the focal length of the third lens, R5e is the radius of curvature of the first surface of the third lens, and R6e is the radius of curvature of the second surface of the third lens. Satisfying -2.0 < f3e / (R5e + R6e) < 0, by controlling the ratio of the focal length of the third lens to the sum of the surface radii of curvature, the center thickness of the third lens can be effectively controlled. On the one hand, it is beneficial to the shaping of the third lens, and on the other hand, it is beneficial to control the internal reflection ghost image of the third lens.

[0073] In an exemplary embodiment, the total focal length f of the visual optical system may satisfy 0.8 < f < 1.5. Satisfying 0.8 < f < 1.5, by controlling the value of the total focal length of the visual optical system to be a smaller value, it is beneficial to increase the field of view angle of the visual optical system, so that the system can capture more eye movement information.

[0074] In an exemplary embodiment, there is a certain angle between the second optical axis Z2 of the second optical system and the first optical axis Z1 of the first optical system, and this angle θ satisfies 0° < θ < 90°. By controlling the angle between the second optical axis of the second optical system and the first optical axis of the first optical system, on the one hand, the second optical system is placed outside the first optical system, thus ensuring the function of the first optical system, and on the other hand, the second optical system can capture the eye image, thereby completing eye tracking.

[0075] In an exemplary embodiment, the second optical system of the visual optical system further includes a diaphragm, which can be disposed on one side close to the first surface of the first lens. The visual optical system can satisfy 0 mm < Tz < 15.0 mm, where Tz is the distance along the first optical axis between the intersection of the second side surface of the element group closest to the display side in the first optical system and the first optical axis and the intersection of the center of the diaphragm of the second optical system and the second optical axis. The visual optical system can further satisfy 0 mm < Tz < 10.0 mm. By controlling the above interval distance, the z-direction height between the second optical system and the first optical system can be controlled, thereby effectively controlling the second optical system to be located between the first optical system and the screen, ensuring the feasibility of the Eye Tracking solution.

[0076] In an exemplary embodiment, the visual optical system can satisfy 5 mm < Ty < 25.0 mm, where Ty is the distance along a direction perpendicular to the first optical axis between the intersection of the second side surface of the element group closest to the display side in the first optical system and the first optical axis and the intersection of the center of the diaphragm of the second optical system and the second optical axis. The visual optical system can further satisfy 5 mm < Ty < 25.0 mm. By controlling the above interval, the aperture of the bracket of the second optical system is controlled, making the aperture of the bracket of the second optical system between the aperture of the first optical system and the size of the screen, which is beneficial to the assembly of the second optical system.

[0077] In an exemplary embodiment of the visual optical system, in the first optical system, the second side surface of the first lens is attached to a reflective polarizing element, and the second side surface of the reflective polarizing element is attached to a quarter-wave plate. The second side surface of the first lens can be a flat surface. Exemplarily, in a near-eye display system, the first lens adopts a flat film attachment method, and a composite film composed of a reflective polarizing element and a quarter-wave plate is attached to the second side surface of the first lens, which is beneficial to reducing the influence of film orange peel on performance.

[0078] According to the visual optical system of the above embodiments of the present application, by reasonably setting the curvature radius, central thickness, surface shape, refractive index, Abbe number of each optical element group and each optical element, as well as parameters such as the total effective focal length of the visual optical system, it is beneficial to improve the imaging effect and ensure the optical performance of the system; and by reasonably setting parameters such as the diaphragm position, the air gap between the lenses, and the distance to the display or imaging surface, it is beneficial to ensure the molding and strength of the lenses, beneficial to reducing the sensitivity of the lenses; at the same time, it is beneficial to restrict the total length of the optical system and improve the portability of the device; it can also increase the field of view angle and enhance the user experience.

[0079] The following further describes specific embodiments of the visual optical system applicable to the above embodiments with reference to the accompanying drawings.

[0080] Embodiment 1

[0081] The following reference Figures 3 to 5 The visual optical system according to the first embodiment of the present application is described.

[0082] like Figure 3 As shown, the visual optical system of this embodiment may include a first optical system and a second optical system. The first optical system includes: a first element group, a second element group and a third element group arranged in sequence from the near-eye side to the display side along the first optical axis, wherein the first element group includes a first lens L1, a reflective polarizing element RP and a quarter-wave plate QWP; the second element group includes a second lens L2; ​​and the third element group includes a third lens L3. A display may be provided on the second side of the first optical system.

[0083] In this embodiment, the first lens L1 has positive power, the first side surface S1' is convex, and the second side surface S2' is flat. The reflective polarizing element RP is at least partially attached to the second side surface S2' of the first lens L1, and the quarter wave plate QWP is at least partially attached to the second side surface of the reflective polarizing element RP.

[0084] The second lens L2 has positive power, the first side surface S3 ′ is a convex surface, and the second side surface S4 ′ is a convex surface.

[0085] The third lens L3 has positive refractive power, the first side surface S5 ′ is a concave surface, and the second side surface S6 ′ is a convex surface.

[0086] like Figure 4 As shown, the second optical system includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4, which are arranged in sequence from the object side to the image side along the second optical axis.

[0087] In this embodiment, the first lens E1 may have negative power, the first surface S1 is a concave surface, and the second surface S2 is a concave surface. The second lens E2 may have positive power, the first surface S3 is a convex surface, and the second surface S4 is a concave surface. The third lens E3 may have positive power, the first surface S5 is a concave surface, and the second surface S6 is a convex surface. The fourth lens E4 may have positive power, the first surface S7 is a convex surface, and the second surface S8 is a concave surface.

[0088] As an exemplary embodiment, the second optical system may further include a stop STO, which may be disposed on a side close to the first surface of the first lens E1. The second optical system may further include a protective glass or filter E5 for protecting a photosensitive element located on the imaging surface S11.

[0089] Table 1 shows a basic parameter table of the visual optical system of Example 1, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0090] Face number Surface type Radius of curvature thickness Refractive Index Abbe number Cone coefficient Near the eye Spherical endless 15.0000 S1' Aspheric 94.2231 7.1462 1.54 55.92 0.0000 S2' Spherical endless 0.1000 1.50 56.00 RP Spherical endless 0.1000 1.50 56.00 QWP Spherical endless 0.5000 S3' Aspheric 173.6732 7.0000 1.54 55.92 0.0000 S4' Aspheric -197.7719 2.5056 0.0000 S5' Aspheric -399.9734 3.5000 1.54 55.92 0.0000 S6' Aspheric -114.4096 0.0000 0.0000 Tz / Ty STO Spherical endless 0.0304 S1 Aspheric -11.6649 0.3000 1.57 29.91 0.0000 S2 Aspheric 1.0742 0.0404 0.0000 S3 Aspheric 0.5400 0.3000 1.65 19.24 0.0000 S4 Aspheric 0.9512 0.0561 0.0000 S5 Aspheric -2.4888 0.4668 1.54 56.14 0.0000 S6 Aspheric -0.6853 0.0300 0.0000 S7 Aspheric 0.6339 0.3925 1.65 19.24 -1.0000 S8 Aspheric 0.8954 0.0713 0.0000 S9 Spherical endless 0.2100 1.52 64.20 S10 Spherical endless 0.4300 S11 Spherical endless -0.0050 Display side

[0091] Table 1

[0092] In this embodiment, the first side surface S1' of the first lens L1, the first side surface S3' and the second side surface S4' of the second lens L2, the first side surface S5' and the second side surface S6' of the third lens L3, the first surface S1 and the second surface S2 of the first lens E1, the first surface S3 and the second surface S4 of the second lens E2, the first surface S5 and the second surface S6 of the third lens E3, and the first surface S7 and the second surface S8 of the fourth lens E4 are all aspherical surfaces, and the surface shape x of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0093]

[0094] Wherein, x is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface. Table 2 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A 10 , A 12 , A 14 and A 16 .

[0095] Face number / coefficient A4 A6 A8 A10 A12 A14 A16 S1' 1.7237E+00 -1.0531E-02 1.8280E-02 1.1790E-02 1.9481E-03 -2.2963E-03 4.9674E-04 S3' -1.7897E-01 -4.5955E-02 3.6542E-02 -2.4898E-03 -5.2026E-03 4.4163E-03 -1.1827E-03 S4' -2.0077E-01 -2.0784E-01 -3.5027E-02 3.7970E-03 1.8428E-02 1.3874E-02 -7.2088E-04 S5' -1.7781E+00 -4.2544E-01 -1.1943E-01 -2.8744E-02 5.6071E-03 9.3229E-03 1.8844E-03 S6' -1.0784E-01 -6.9805E-02 -8.2343E-03 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S1 9.7313E-03 -2.9451E-03 -9.1754E-04 1.9580E-04 -1.7899E-04 4.5136E-05 -6.1431E-05 S2 -3.2863E-02 3.4397E-03 -8.8822E-04 1.8945E-04 2.4553E-05 -3.8122E-05 1.0442E-05 S3 -1.0712E-01 3.0855E-03 -3.0317E-03 5.5134E-04 -2.6057E-05 7.6738E-05 -2.2467E-05 S4 -8.9602E-02 -2.2287E-03 1.3166E-04 1.1821E-04 -2.3671E-04 5.2161E-05 -2.7513E-06 S5 9.8766E-02 -2.0941E-02 7.2624E-03 -3.5343E-03 1.6253E-03 4.5222E-04 -4.9459E-04 S6 6.8644E-02 1.8287E-02 2.7685E-03 -7.5355E-04 1.7051E-04 -6.0324E-04 1.8412E-04 S7 -3.0163E-01 1.9931E-02 1.8006E-03 1.3702E-03 5.3668E-04 -9.0251E-04 -2.4516E-04 S8 -4.5789E-01 9.3755E-03 3.5542E-03 1.4647E-04 3.7005E-03 -1.5009E-03 6.8907E-04

[0096] Table 2

[0097] Figure 5 The diffraction MTF (Modulation Transfer Function) curve of the visual optical system of the first embodiment in different fields of view is shown. The horizontal axis Spatial Frequency represents the spatial frequency of line pairs / mm (lp / mm), and the vertical axis Modulation is the modulation transfer function. Figure 5 It can be seen that the visual optical system of this embodiment has good contrast within a spatial frequency of 30lp / mm and a high comprehensive resolution level.

[0098] Embodiment 2

[0099] The following reference Figures 6 to 8 The visual optical system according to the second embodiment of the present application is described. Figure 6 The structure diagram of the visual optical system according to the second embodiment of the present application is shown. In this embodiment and the following embodiments, for the sake of brevity, some descriptions similar to the first embodiment will be omitted.

[0100] like Figure 6As shown, the visual optical system of this embodiment may include a first optical system and a second optical system. The first optical system includes: a first element group, a second element group and a third element group arranged in sequence from the near-eye side to the display side along the first optical axis, wherein the first element group includes a first lens L1, a reflective polarizing element RP and a quarter-wave plate QWP; the second element group includes a second lens L2; ​​and the third element group includes a third lens L3. A display may be provided on the second side of the first optical system.

[0101] In this embodiment, the first lens L1 has positive optical power, the first side surface S1' is a convex surface, the second side surface S2' is a plane, the reflective polarizing element RP is at least partially bonded to the second side surface S2' of the first lens L1, and the quarter-wave plate QWP is at least partially bonded to the second side surface of the reflective polarizing element RP.

[0102] The second lens L2 has negative optical power, the first side surface S3 ′ is a convex surface, and the second side surface S4 ′ is a concave surface.

[0103] The third lens L3 has positive power, the first side surface S5 ′ is a convex surface, and the second side surface S6 ′ is a convex surface.

[0104] like Figure 7 As shown, the second optical system includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 arranged in sequence from the object side to the image side along the second optical axis. The second optical system may also include a stop STO disposed on the first surface side close to the first lens E1, and a protective glass or filter E5 for protecting the photosensitive element located on the imaging surface S11.

[0105] In this embodiment, the first lens E1 may have negative power, the first surface S1 is concave, and the second surface S2 is convex. The second lens E2 may have positive power, the first surface S3 is convex, and the second surface S4 is concave. The third lens E3 may have positive power, the first surface S5 is concave, and the second surface S6 is convex. The fourth lens E4 may have positive power, the first surface S7 is convex, and the second surface S8 is concave.

[0106] Table 3 shows the basic parameter table of the visual optical system of Example 2, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0107] Face number Surface type Radius of curvature thickness Refractive Index Abbe number Cone coefficient Near the eye Spherical endless 12.0000 S1' Aspheric 62.1320 2.4847 1.54 55.92 0.0000 S2' Spherical endless 0.1000 1.50 56.00 RP Spherical endless 0.1000 1.50 56.00 QWP Spherical endless 0.3184 S3' Aspheric 486.3949 0.6000 1.62 23.52 0.0000 S4' Aspheric 48.0118 0.2260 0.0000 S5' Aspheric 44.7715 9.3206 1.54 55.92 0.0000 S6' Aspheric -60.5294 0.0000 0.0000 Tz / Ty STO Spherical endless 0.0561 S1 Aspheric -0.5382 0.3000 1.54 49.64 0.0000 S2 Aspheric -59.3317 0.0300 0.0000 S3 Aspheric 0.3930 0.3000 1.54 56.14 0.0000 S4 Aspheric 0.9957 0.0750 0.0000 S5 Aspheric -1.0098 0.5072 1.54 56.14 0.0000 S6 Aspheric -0.5381 0.0300 -1.0000 S7 Aspheric 0.9938 0.4686 1.65 19.24 0.0000 S8 Aspheric 2.0973 0.0300 0.0000 S9 Spherical endless 0.2100 1.52 64.20 S10 Spherical endless 0.4444 S11 Spherical endless 0.0000 Display side

[0108] Table 3

[0109] In this embodiment, the first side surface S1' of the first lens L1, the first side surface S3' and the second side surface S4' of the second lens L2, the first side surface S5' and the second side surface S6' of the third lens L3, the first surface S1 and the second surface S2 of the first lens E1, the first surface S3 and the second surface S4 of the second lens E2, the first surface S5 and the second surface S6 of the third lens E3, and the first surface S7 and the second surface S8 of the fourth lens E4 are all aspherical surfaces. The surface shape x of each aspherical lens can be defined by using but not limited to the aspherical formula (1) in the first embodiment.

[0110] Table 4 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A59, A60, A61, A62, A63, A70, A71, A72, A73, A 10 , A 12 , A 14 and A 16 .

[0111] Face number / coefficient A4 A6 A8 A10 A12 A14 A16 S1' -6.1153E-01 -3.3166E-01 8.0580E-03 -1.1441E-02 -2.5244E-03 8.2930E-03 1.6853E-03 S3' -6.0641E-01 2.6268E-01 -7.4653E-02 8.7985E-02 -2.9213E-02 1.9815E-03 -7.5513E-04 S4' -1.0827E+00 -2.2629E-01 -5.0583E-02 5.2634E-02 -2.9721E-02 1.0318E-02 5.9363E-04 S5' -1.6093E+00 -1.2201E-01 1.8394E-02 -3.2984E-02 1.2357E-02 -1.0253E-02 1.6463E-03 S6' 4.2211E-03 -1.3171E-02 -1.4171E-03 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S1 -4.9820E-04 -8.5735E-03 -2.0187E-04 7.8926E-04 -1.2418E-04 -2.2426E-04 -1.0187E-05 S2 -7.3658E-02 1.4461E-02 -3.2792E-03 9.4565E-04 -4.1960E-04 -1.0050E-05 -1.1930E-04 S3 -1.7375E-01 7.2456E-03 -5.5176E-03 6.5799E-04 -3.9686E-04 1.6944E-04 -4.1445E-05 S4 -8.9329E-02 -6.4437E-03 6.5873E-05 -2.6281E-04 -1.3780E-05 1.5518E-05 -5.6596E-06 S5 9.7945E-02 -1.4810E-02 4.3659E-03 -8.7729E-04 1.4100E-04 3.3040E-05 1.5118E-05 S6 -9.2934E-03 1.7298E-02 5.5158E-03 -1.7493E-03 4.0194E-04 -3.3446E-04 8.4028E-05 S7 -2.7015E-01 1.7947E-02 8.2099E-03 -1.6157E-03 9.4741E-04 -1.2046E-03 3.1861E-04 S8 -3.5002E-01 2.3383E-02 5.8652E-03 -6.5533E-04 2.3091E-03 -4.4268E-04 4.9400E-04

[0112] Table 4

[0113] Figure 8 The diffraction MTF curves of the visual optical system of the second embodiment in different fields of view are shown. The horizontal axis Spatial Frequency represents the spatial frequency of line pairs / mm (lp / mm), and the vertical axis Modulation is the optical modulation transfer function. Figure 8 It can be seen that the visual optical system of this embodiment has good contrast within a spatial frequency of 30lp / mm and a high comprehensive resolution level.

[0114] Embodiment 3

[0115] The following reference Figures 9 to 11 Describe the visual optical system according to the third embodiment of the present application. Fig. 9 A schematic structural diagram of a visual optical system according to Embodiment 3 of the present application is shown.

[0116] like Fig. 9 As shown, the visual optical system of this embodiment may include a first optical system and a second optical system. The first optical system includes: a first element group, a second element group and a third element group arranged in sequence from the near-eye side to the display side along the first optical axis, wherein the first element group includes a first lens L1, a reflective polarizing element RP and a quarter-wave plate QWP; the second element group includes a second lens L2; ​​and the third element group includes a third lens L3. A display may be provided on the second side of the first optical system.

[0117] In this embodiment, the first lens L1 has positive optical power, the first side surface S1' is a convex surface, the second side surface S2' is a plane, the reflective polarizing element RP is at least partially bonded to the second side surface S2' of the first lens L1, and the quarter-wave plate QWP is at least partially bonded to the second side surface of the reflective polarizing element RP.

[0118] The second lens L2 has positive power, the first side surface S3 ′ is a convex surface, and the second side surface S4 ′ is a concave surface.

[0119] The third lens L3 has positive power, the first side surface S5 ′ is a convex surface, and the second side surface S6 ′ is a convex surface.

[0120] like Fig.10 As shown, the second optical system includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 arranged in sequence from the object side to the image side along the second optical axis. The second optical system may also include a stop STO disposed on the first surface side close to the first lens E1, and a protective glass or filter E5 for protecting the photosensitive element located on the imaging surface S11.

[0121] In this embodiment, the first lens E1 may have negative power, the first surface S1 is a concave surface, and the second surface S2 is a convex surface. The second lens E2 may have positive power, the first surface S3 is a convex surface, and the second surface S4 is a convex surface. The third lens E3 may have positive power, the first surface S5 is a convex surface, and the second surface S6 is a convex surface. The fourth lens E4 may have positive power, the first surface S7 is a concave surface, and the second surface S8 is a convex surface.

[0122] Table 5 shows a basic parameter table of the visual optical system of Example 3, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0123] Face number Surface type Radius of curvature thickness Refractive Index Abbe number Cone coefficient Near the eye Spherical endless 12.0000 S1' Aspheric 66.6014 3.6893 1.54 55.92 0.0000 S2' Spherical endless 0.1000 1.50 56.00 RP Spherical endless 0.1000 1.50 56.00 QWP Spherical endless 0.5000 S3' Aspheric 165.3041 2.0421 1.54 55.92 0.0000 S4' Aspheric 181.2680 0.2421 0.0000 S5' Aspheric 140.1847 6.8952 1.54 55.92 0.0000 S6' Aspheric -61.4727 0.0000 0.0000 Tz / Ty STO Spherical endless 0.0503 S1 Aspheric -0.8208 0.3000 1.65 19.24 0.0000 S2 Aspheric -12.7945 0.0300 0.0000 S3 Aspheric 2.5746 0.6474 1.54 56.14 0.0000 S4 Aspheric -1.5709 0.0300 0.0000 S5 Aspheric 0.5649 0.3845 1.65 19.24 1.0000 S6 Aspheric -110.1102 0.1812 0.0000 S7 Aspheric -0.3562 0.3573 1.65 19.24 1.0000 S8 Aspheric -0.4837 0.0300 1.0000 S9 Spherical endless 0.2100 1.52 64.20 S10 Spherical endless 0.4700 S11 Spherical endless 0.0000 Display side

[0124] Table 5

[0125] In this embodiment, the first side surface S1' of the first lens L1, the first side surface S3' and the second side surface S4' of the second lens L2, the first side surface S5' and the second side surface S6' of the third lens L3, the first surface S1 and the second surface S2 of the first lens E1, the first surface S3 and the second surface S4 of the second lens E2, the first surface S5 and the second surface S6 of the third lens E3, and the first surface S7 and the second surface S8 of the fourth lens E4 are all aspherical surfaces. The surface shape x of each aspherical lens can be defined by using but not limited to the aspherical formula (1) in the first embodiment.

[0126] Table 6 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A 10 , A 12 , A14 and A 16 .

[0127]

[0128]

[0129] Table 6

[0130] Fig.11 The diffraction MTF curves of the visual optical system of the third embodiment in different fields of view are shown. The horizontal axis Spatial Frequency represents the spatial frequency of line pairs / mm (lp / mm), and the vertical axis Modulation is the optical modulation transfer function. Fig.11 It can be seen that the visual optical system of this embodiment has good contrast within a spatial frequency of 30lp / mm and a high comprehensive resolution level.

[0131] Embodiment 4

[0132] The following reference Figure 12 to Figure 14 Describe the visual optical system according to the fourth embodiment of the present application. Fig.12 A schematic structural diagram of a visual optical system according to a fourth embodiment of the present application is shown.

[0133] like Fig.12 As shown, the visual optical system of this embodiment may include a first optical system and a second optical system. The first optical system includes: a first element group, a second element group and a third element group arranged in sequence from the near-eye side to the display side along the first optical axis, wherein the first element group includes a first lens L1, a reflective polarizing element RP and a quarter-wave plate QWP; the second element group includes a second lens L2; ​​and the third element group includes a third lens L3. A display may be provided on the second side of the first optical system.

[0134] In this embodiment, the first lens L1 has negative optical power, the first side surface S1' is a concave surface, the second side surface S2' of the first lens L1 is a convex surface, the reflective polarizing element RP is at least partially bonded to the second side surface S2' of the first lens L1, and the quarter-wave plate QWP is at least partially bonded to the second side surface of the reflective polarizing element RP.

[0135] The second lens L2 has positive refractive power, the first side surface S3 ′ is a concave surface, and the second side surface S4 ′ is a convex surface.

[0136] The third lens L3 has negative optical power, the first side surface S5' is a concave surface, and the second side surface S6' is a convex surface.

[0137] like Fig.13As shown, the second optical system includes: a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4 arranged in sequence from the object side to the image side along the second optical axis. In this embodiment, the second optical system may further include a stop STO disposed on the first surface side close to the first lens E1, and a protective glass or filter E5 for protecting the photosensitive element located on the imaging surface S11.

[0138] In this embodiment, the first lens E1 may have positive power, the first surface S1 is a concave surface, and the second surface S2 is a convex surface. The second lens E2 may have positive power, the first surface S3 is a concave surface, and the second surface S4 is a concave surface. The third lens E3 may have positive power, the first surface S5 is a concave surface, and the second surface S6 is a convex surface. The fourth lens E4 may have negative power, the first surface S7 is a convex surface, and the second surface S8 is a concave surface.

[0139] Table 7 shows a basic parameter table of the visual optical system of Example 4, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0140] Face number Surface type Radius of curvature thickness Refractive Index Abbe number Cone coefficient Near the eye Spherical endless 12.0000 S1' Aspheric -18.5496 0.7897 1.62 23.52 0.0000 S2' Aspheric -21.6377 0.1000 1.50 56.00 RP Aspheric -21.6377 0.1000 1.50 56.00 QWP Aspheric -21.6377 0.2500 S3' Aspheric -30.7029 3.2751 1.54 55.92 0.0000 S4' Aspheric -15.9703 0.2500 0.0000 S5' Aspheric -16.2887 3.5000 1.62 23.52 0.0000 S6' Aspheric -21.5780 0.0000 0.0000 Tz / Ty STO Spherical endless 0.0534 S1 Aspheric -1.3967 0.1373 1.57 29.91 0.0000 S2 Aspheric -1.1220 0.0962 0.0000 S3 Aspheric -4.1421 0.1201 1.65 19.24 0.0000 S4 Aspheric 2.2855 0.1458 0.0000 S5 Aspheric -8.5185 0.4485 1.54 56.14 0.0000 S6 Aspheric -0.5777 0.0174 -1.0000 S7 Aspheric 2.0319 0.1752 1.65 19.24 -1.0000 S8 Aspheric 1.6539 0.1861 -1.0000 S9 Spherical endless 0.2100 1.52 64.20 S10 Spherical endless 0.4443 S11 Spherical endless 0.0000 Display side

[0141] Table 7

[0142] In this embodiment, the first side surface S1' and the first side surface S2' of the first lens L1, the first side surface S3' and the second side surface S4' of the second lens L2, the first side surface S5' and the second side surface S6' of the third lens L3, the first surface S1 and the second surface S2 of the first lens E1, the first surface S3 and the second surface S4 of the second lens E2, the first surface S5 and the second surface S6 of the third lens E3, and the first surface S7 and the second surface S8 of the fourth lens E4 are all aspherical surfaces. The surface shape x of each aspherical lens can be defined by but not limited to the aspherical formula (1) in the first embodiment.

[0143] Table 8 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A 10 , A 12 , A 14 and A 16 .

[0144] Face number / coefficient A4 A6 A8 A10 A12 A14 A16 S1' -1.1242E-01 2.1702E-02 1.8514E-01 -2.8267E-03 1.3801E-02 -1.4578E-02 3.2945E-03 S2' -5.2829E-02 1.0902E-01 3.1306E-02 6.8431E-03 1.6485E-03 6.1464E-04 -9.2957E-04 S3' -1.5098E+00 3.4975E-01 -2.2104E-01 4.1582E-02 -5.3277E-02 1.1293E-02 -9.2157E-03 S4' -3.9932E-01 -3.5499E-02 7.9833E-02 1.7820E-02 3.6225E-02 -4.3785E-03 1.6630E-03 S5' 1.1224E+00 -1.0458E-01 6.5785E-02 -1.9573E-02 2.5698E-02 -3.9078E-03 3.1698E-03 S6' 9.3449E-03 -1.3907E-03 -1.2398E-04 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S1 -2.3683E-02 -2.5877E-03 -4.9194E-04 -6.6926E-05 -5.4380E-05 -3.4536E-05 -1.4807E-05 S2 -3.0421E-02 7.2981E-04 -3.4213E-04 9.3350E-06 -6.6429E-06 1.9763E-06 1.8429E-06 S3 -8.9467E-02 -2.0244E-03 -4.1298E-04 -1.8461E-04 -2.8392E-05 -6.7493E-06 -1.2150E-06 S4 -1.1830E-01 -1.4939E-03 3.6218E-04 -6.3973E-04 1.5840E-04 -4.1661E-05 8.1538E-06 S5 8.8540E-02 -1.3076E-02 1.7821E-03 -4.2198E-04 1.2878E-04 -4.5006E-05 1.3715E-05 S6 -9.4144E-03 1.4248E-03 2.8232E-03 4.5450E-04 2.1786E-05 -2.6140E-05 -6.2361E-06 S7 -4.5485E-01 4.5717E-02 -5.2047E-04 9.4696E-04 7.1605E-05 -3.8705E-04 5.9336E-05 S8 -7.9021E-01 1.1645E-01 -1.8970E-02 6.9221E-03 -1.5486E-03 3.1619E-04 -6.0664E-05

[0145] Table 8

[0146] Fig.14 The diffraction MTF curves of the visual optical system of the fourth embodiment in different fields of view are shown. The horizontal axis Spatial Frequency represents the spatial frequency of line pairs / mm (lp / mm), and the vertical axis Modulation is the optical modulation transfer function. Fig.14It can be seen that the visual optical system of this embodiment has good contrast within a spatial frequency of 30lp / mm and a high comprehensive resolution level.

[0147] Table 9 shows the optical parameters of the visual optical system of the above-mentioned embodiments 1 to 4, including the focal length f of the visual optical system, the focal length of each lens, the spacing distance Tz from the intersection of the second side surface of the component group closest to the display side in the first optical system and the first optical axis to the intersection of the aperture center of the second optical system and the second optical axis along the first optical axis direction, and the spacing distance Ty from the intersection of the second side surface of the component group closest to the display side in the first optical system and the first optical axis to the intersection of the aperture center of the second optical system and the second optical axis along the direction perpendicular to the first optical axis, etc. Among them, the units of the distance and focal length values ​​are both millimeters (mm).

[0148] Parameters / Examples one two three Four f(mm) 1.00 0.99 1.06 0.91 f1m(mm) 175.66 115.83 124.16 -237.08 f2m(mm) 173.53 -86.00 3349.61 57.58 f3m(mm) 297.47 49.51 80.63 -143.57 f1e(mm) -1.71 -1.00 -1.37 8.45 f2e(mm) 1.50 1.03 1.92 625.71 f3e(mm) 1.62 1.56 0.87 0.99 f4e(mm) 1.61 2.50 20.75 -4.01 Tz(mm) 0.00 9.03 3.66 1.29 Ty(mm) 11.41 18.39 12.00 12.00

[0149] Table 9

[0150] In summary, the visual optical systems of the above-mentioned embodiments 1 to 4 meet the conditions shown in Table 10 below.

[0151] Conditional / Example one two three Four TDm / TDe 13.15 7.69 7.03 7.25 f1m / f3m 0.59 2.34 1.54 1.65 TDm / f3m 0.07 0.27 0.17 -0.06 CT3m / TDm 0.17 0.71 0.51 0.42 (N1m+N2m)*T12m / (f2m / f1m) 1.56 -1.35 0.06 -3.25 N3m / N1e 0.98 1.00 0.93 1.03 |V3m-V1e| 26.01 6.29 36.69 6.39 TTLe / TDe 1.45 1.40 1.37 1.74 (N2e*CT2e) / (N3e*CT3e) 0.69 0.59 1.57 0.29 f1e / f2e -1.14 -0.97 -0.71 0.01 |f3e / f4e| 1.00 0.62 0.04 0.25 R1m / R3m 0.54 0.13 0.40 0.60 R6m / R5m 0.29 -1.35 -0.44 1.32 |R8e| / R1e -0.08 -3.90 -0.59 -1.18 f3e / (R5e+R6e) -0.51 -1.01 -0.01 -0.11

[0152] Table 10

[0153] 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 the utility model 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 utility model. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other to form a technical solution.

Claims

1. A visual optical system, characterized in that: It includes a first optical system and a second optical system. The first optical system sequentially includes, along a first optical axis, from the near-eye side to the display side: a first element group, a second element group, and a third element group. The first element group includes a first lens, a reflective polarizing element, and a quarter-wave plate; the second element group includes a second lens; the third element group includes a third lens. The second optical system sequentially includes, along a second optical axis, from a first side to a second side: a first lens with a focal power, a second lens with a positive focal power, a third lens with a positive focal power, and a fourth lens with a focal power. Wherein, the distance TDm on the first optical axis from the first side surface of the first element group to the second side surface of the third element group, and the distance TDe on the second optical axis from the first surface of the first lens to the second surface of the fourth lens satisfy: 5.0 < TDm / TDe < 15.

0.

2. The visual optical system according to claim 1, wherein: The focal length f1m of the first element group and the focal length f3m of the third element group satisfy: 0.3 < f1m / f3m < 2.

5.

3. The visual optical system according to claim 1, wherein: The distance TDm on the first optical axis from the first side surface of the first element group to the second side surface of the third element group, and the focal length f3m of the third element group satisfy: -0.01 < TDm / f3m < 0.

50.

4. The visual optical system according to claim 1, wherein: The distance TDm on the first optical axis from the first side surface of the first element group to the second side surface of the third element group, and the central thickness CT3m of the third lens on the first optical axis satisfy: 0.1 < CT3m / TDm < 0.

9.

5. The visual optical system according to claim 1, wherein: The refractive index N1m of the first lens, the refractive index N2m of the second lens, the air gap T12m on the first optical axis between the first element group and the second element group, the focal length f1m of the first element group, and the focal length f2m of the second element group satisfy: -3.5 < (N1m + N2m)*T12m / (f2m / f1m) < 2.

0.

6. The visual optical system according to claim 1, wherein: The refractive index N3m of the third lens and the refractive index N1e of the first lens satisfy: 0.8 < N3m / N1e < 1.20; the Abbe number V3m of the third lens and the Abbe number V1e of the first lens satisfy: 0 < |V3m - V1e| < 40.

0.

7. The visual optical system according to claim 1, wherein: The distance TTLe on the second optical axis from the first surface of the first lens to the imaging surface, and the distance TDe on the second optical axis from the first surface of the first lens to the second surface of the fourth lens satisfy: 1.30 < TTLe / TDe < 1.

80.

8. The visual optical system according to claim 1, wherein: The refractive index N2e of the second lens, the refractive index N3e of the third lens, the central thickness CT2e of the second lens on the second optical axis, and the central thickness CT3e of the third lens on the second optical axis satisfy: 0.2 < (N2e*CT2e) / (N3e*CT3e) < 1.

8.

9. The visual optical system according to claim 1, wherein: The focal length f1e of the first lens and the focal length f2e of the second lens satisfy: -1.50 < f1e / f2e < 0.

09.

10. The visual optical system according to claim 1, wherein: The focal length f3e of the third lens and the focal length f4e of the fourth lens satisfy: 0.01<|f3e / f4e|<1.

20.

11. The visual optical system according to claim 1, wherein: The curvature radius R1m of the first side surface of the first lens and the curvature radius R3m of the first side surface of the second lens satisfy: <R1m / R3m<1.0。 12. The visual optical system according to claim 1 or 10, wherein: The curvature radius R5m of the first side surface of the third lens and the curvature radius R6m of the second side surface of the third lens satisfy: -2.0 <R6m / R5m<2.0。 13. The visual optical system according to any one of claims 1, 9 or 10, wherein: A curvature radius R1e of the first surface of the first lens and a curvature radius R8e of the second surface of the fourth lens satisfy: -5.0<|R8e| / R1e<0.

14. The visual optical system according to claim 1 or 10, wherein: The focal length f3e of the third lens, the curvature radius R5e of the first surface of the third lens, and the curvature radius R6e of the second surface of the third lens satisfy: -2.0 <f3e / (R5e+R6e)<0。 15. The visual optical system according to any one of claims 1 to 10, wherein: The total focal length f of the visual optical system satisfies: 0.8 <f<1.5。 16. The visual optical system according to any one of claims 1 to 10, wherein: The second optical system is disposed between the first optical system and the display side, a first side of the second optical system is relatively close to the near-eye side, and a second side of the second optical system is relatively close to the display side.

17. The visual optical system according to any one of claims 1 to 10, wherein: An angle θ between the second optical axis and the first optical axis satisfies: 0°<θ<90°.

18. The visual optical system according to any one of claims 1 to 10, wherein: The second optical system further includes an aperture, which is arranged on a side close to the first surface of the first lens; the spacing distance Tz from the intersection of the second side surface of the element group closest to the display side in the first optical system and the first optical axis to the intersection of the aperture center of the second optical system and the second optical axis along the first optical axis direction satisfies: 0 mm <Tz<15.0mm。 19. The visual optical system according to any one of claims 1 to 10, wherein: The second optical system further includes an aperture, which is arranged on a side close to the first surface of the first lens; the spacing distance Ty between the intersection of the second side surface of the element group closest to the display side in the first optical system and the first optical axis and the intersection of the aperture center of the second optical system and the second optical axis along the direction perpendicular to the first optical axis satisfies: 5 mm <Ty<25.0mm。 20. The visual optical system according to any one of claims 1 to 10, wherein: The second side surface of the first lens is at least partially in contact with the reflective polarizing element, and the second side surface of the reflective polarizing element is at least partially in contact with the quarter-wave plate; the second side surface of the first lens is a plane.

Images