Optical systems and virtual reality equipment

Abstract

The present application provides an optical system and a virtual reality device, which relate to the technical field of optical systems and are used to solve the technical problems in the related art that the optical system has a low focusing speed and unclear recognition of environmental information at different object distances. The optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence along the light transmission direction. The optical system also includes an aperture, and the third lens is also arranged at the aperture, or is also arranged at a position close to the aperture; wherein the third lens includes an adjustable lens, and the adjustable lens is used to adjust the diopter of the light according to a voltage to achieve the purpose of changing the curvature and thus changing the focusing distance. The device has the advantages of millisecond-level automatic clear focusing, and has low power consumption, no magnetic interference, and no problems affected by gravity posture differences.

Description

Technical Field

[0001] The present application relates to the technical field of optical systems, and in particular to an optical system and a virtual reality device. Background Art

[0002] Virtual reality (VR) technology is a computer-generated, interactive, immersive visual virtual environment that can provide users with a completely enclosed virtual space and simulate senses such as vision, hearing, and touch, allowing users to enter a completely immersed virtual world. It is widely used in urban planning, driving training, interior design and other fields.

[0003] The virtual reality device includes a display screen and an optical system. The light emitted by the display screen is transmitted and amplified by the optical system, and then transmitted to the aperture surface. The human eye is located at the aperture surface or near the aperture surface; that is, the human eye receives the magnified virtual image of the display screen.

[0004] Among them, the optical system in the relevant technology includes a See-Through function, which collects real-time views of the surrounding environment through a camera and displays them through a screen, thereby increasing the user's perception of the surrounding environment and giving the user a feeling that the human eye can directly see the real world around them through the headset, breaking the limitations of a completely enclosed virtual space and allowing users to step out of the VR world; at the same time, it also allows users to understand the real environment of the border area and improve safety; it also allows users to interact with the external real world without removing the headset, such as: touching and opening the controller, signing for express delivery, sending and receiving text messages, etc., thereby enhancing the experience of virtual reality devices.

[0005] However, the optical system in the related art uses a fixed-focus optical perspective system, which has the problem of unclear recognition of environmental information at different object distances, resulting in a poor experience. Summary of the invention

[0006] In view of the above problems, the embodiments of the present application provide an optical system and a virtual reality device to solve the problems in the related art that the optical system has a low focusing speed and unclear recognition of environmental information at different object distances.

[0007] In order to achieve the above objectives, the embodiments of the present application provide the following technical solutions:

[0008] A first aspect of an embodiment of the present application provides an optical system, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence along a light transmission direction; the optical system also includes an aperture, and the third lens is also arranged at the aperture, or is also arranged at a position close to the aperture; wherein the third lens includes an adjustable lens, and the adjustable lens is used to adjust the refractive power of the light according to a voltage.

[0009] In a possible implementation, the optical system further includes a filter element and an imaging element. In the light transmission direction, the filter element and the imaging element are both located behind the seventh lens, and the filter element and the imaging element are arranged in sequence.

[0010] In a possible implementation, the surfaces of the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all aspherical, and the surfaces of the third lens, the filter element and the imaging element are all spherical.

[0011] In a possible implementation, the first lens includes a first lens object side surface and a first lens image side surface, the first lens object side surface is a convex surface convex toward the object side, and the first lens image side surface is a concave surface convex toward the object side; the second lens includes a second lens object side surface and a second lens image side surface, the second lens object side surface is a concave surface convex toward the object side, and the second lens image side surface is a convex surface convex toward the image side; the fourth lens includes a fourth lens object side surface and a fourth lens image side surface, the fourth lens object side surface is a convex surface convex toward the object side, and the fourth lens image side surface is a convex surface convex toward the image side. The fifth lens comprises a fifth lens object side surface and a fifth lens image side surface, the fifth lens object side surface is a concave surface convex toward the image side, and the fifth lens image side surface is a concave surface convex toward the object side; the sixth lens comprises a sixth lens object side surface and a sixth lens image side surface, the sixth lens object side surface is a convex surface convex toward the object side, and the sixth lens image side surface is a convex surface convex toward the image side; the seventh lens comprises a seventh lens object side surface and a seventh lens image side surface, the seventh lens object side surface is a concave surface convex toward the image side, and the seventh lens image side surface is a concave surface convex toward the object side.

[0012] In a possible implementation, the optical system satisfies the following relationship:

[0013] F#≤2.2;

[0014] FOV ≥ 115°;

[0015] TTL / IH≤2.14;

[0016] -2.6≤TTL / f1≤-1.8;

[0017] 1.0≤TTL / f2≤1.6;

[0018] 2.4≤TTL / f4≤3.0;

[0019] -2.1≤TTL / f5≤-1.5;

[0020] 2.6≤TTL / f6≤3.4;

[0021] -2.6≤TTL / f7≤-2;

[0022] Among them, F# is the aperture of the optical system, FOV is the field of view of the optical system, TTL is the total length of the lens group in the optical system, IH is the full field of view image height of the diagonal, f1 is the focal length of the first lens, f2 is the focal length of the second lens, -f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

[0023] In a possible implementation, the optical surface of the third lens includes a first surface, a second surface, a third surface and a fourth surface, the radius of curvature of the first surface is infinite, the radius of curvature of the second surface is variable, the radius of curvature of the third surface is variable, and the radius of curvature of the fourth surface is infinite.

[0024] In a possible implementation manner, the thickness of the first surface is 0.1 mm, the thickness of the second surface is 0.28 mm, the thickness of the third surface is 0.02 mm, and the thickness of the fourth surface is 0.1 mm.

[0025] In a possible implementation manner, the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all made of plastic material.

[0026] In a possible implementation manner, the filter element includes an infrared filter.

[0027] A second aspect of an embodiment of the present application provides a virtual reality device, which includes a plurality of optical systems described above.

[0028] The optical system and virtual reality device of the embodiments of the present application, the optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence along the light transmission direction, the optical system also includes an aperture, the third lens is further arranged at the aperture, or is further arranged at a position close to the aperture; wherein the third lens includes an adjustable lens, the adjustable lens is used to adjust the refractive power of the light according to the voltage to achieve the purpose of changing the curvature and thus changing the focusing distance, has the advantages of millisecond-level automatic clear focusing, and has low power consumption, no magnetic interference, and no problems affected by gravity posture differences. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A schematic diagram of the structure of an optical system provided in an embodiment of the present application;

[0031] Figure 2 Parameters of the optical system provided in the embodiment of the present application Figure 1 ;

[0032] Figure 3 Parameters of the optical system provided in the embodiment of the present application Figure 2 ;

[0033] Figure 4 Parameters of the optical system provided in the embodiment of the present application Figure 3 ;

[0034] Figure 5 A schematic diagram of an optical transfer function of an optical system provided in Embodiment 1 of the present application;

[0035] Figure 6 A schematic diagram of optical distortion of an optical system provided in Embodiment 1 of the present application;

[0036] Figure 7 A schematic diagram of an optical transfer function of an optical system provided in Embodiment 2 of the present application;

[0037] Figure 8 A schematic diagram of optical distortion of an optical system provided in Embodiment 2 of the present application;

[0038] Fig. 9 A schematic diagram of an optical transfer function of an optical system provided in Embodiment 3 of the present application;

[0039] Fig.10 A schematic diagram of optical distortion of an optical system provided in Embodiment 3 of the present application;

[0040] Fig.11 A schematic diagram of an optical transfer function of an optical system provided in Embodiment 4 of the present application;

[0041] Fig.12 A schematic diagram of optical distortion of an optical system provided in Embodiment 4 of the present application;

[0042] Fig.13 A schematic diagram of an optical transfer function of an optical system provided in Embodiment 5 of the present application;

[0043] Fig.14 A schematic diagram of optical distortion of an optical system provided in Embodiment 5 of the present application;

[0044] Fig.15 A schematic diagram of an optical transfer function of an optical system provided in Example 6 of the present application;

[0045] Fig.16 A schematic diagram of the optical distortion of the optical system provided in Example 6 of the present application.

[0046] Description of reference numerals:

[0047] 100: first lens;

[0048] 200: second lens;

[0049] 300: the third lens;

[0050] 400: fourth lens;

[0051] 500: fifth lens;

[0052] 600: sixth lens;

[0053] 700: seventh lens;

[0054] 800: filter element;

[0055] 900: Imaging element. DETAILED DESCRIPTION

[0056] As explained in the background technology, the optical system in the related technology has technical problems such as low focusing speed and unclear recognition of environmental information at different object distances. After research by technical personnel, it was found that the reason for the above problems is that the optical system in the related technology is a fixed-focus optical system, and there is a problem of unclear recognition of environmental information at different object distances, which makes the experience worse. In order to solve the problem of unclear recognition, the optical system in the related technology is also provided with a drive motor. First, the optical system automatically determines the subject photographed by the photographer, and measures the distance between the subject and the camera's photosensitive element. Finally, the drive motor pushes the focus device of the lens to the corresponding distance scale, and the automatic zoom is achieved through the drive motor. However, when the automatic zoom is achieved through the drive motor, the focusing speed is low, and the focusing process makes the experience effect poor.

[0057] In response to the above technical problems, an embodiment of the present application provides an optical system, in which the third lens among the first lens, the second lens, the third lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens is located at the aperture, and the third lens is set as an adjustable lens, which can adjust the refractive power of the light according to different voltages, thereby changing the object distance, achieving millisecond-level automatic clear focus, and realizing high-quality imaging.

[0058] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of this application.

[0059] An optical system provided in an embodiment of the present application, referring to Figure 1 , Figure 1 A schematic diagram of the structure of an optical system provided in an embodiment of the present application; the optical system includes a light transmission direction ( Figure 1 In the embodiment of the present invention, a first lens 100, a second lens 200, a third lens 300, a fourth lens 400, a fifth lens 500, a sixth lens 600 and a seventh lens 700 are sequentially arranged (in the horizontal direction shown in FIG). Light is refracted multiple times in the first lens 100, the second lens 200, the third lens 300, the fourth lens 400, the fifth lens 500, the sixth lens 600 and the seventh lens 700 before being projected onto the optical imaging element.

[0060] The optical system also includes an aperture, which is used to simulate the position and size of the human eye pupil. When viewing images using a virtual reality device, the human eye pupil is located at or near the aperture, and the human eye will automatically adjust the size of the pupil according to the brightness of the display device to achieve a good viewing effect. The third lens 300 is also arranged at the aperture, or the third lens 300 is also arranged near the aperture.

[0061] The third lens 300 includes a tunable lens (T lens), which is used to adjust the diopter of light according to voltage. When the voltage value acting on the tunable lens changes, the diopter of light will also change accordingly. When light is emitted from one object to another material with different light density, the propagation direction of the light is deflected. This phenomenon is called refraction. The unit of the refraction (refractive power) is diopter (abbreviated as "D"). 1D refractive power is equivalent to focusing parallel light on a focal length of 1 meter. In other words, the tunable lens can change the system object distance by changing the diopter to achieve the purpose of autofocus.

[0062] The optical system of the embodiment of the present application includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence along the direction of light transmission. The optical system also includes an aperture, and the third lens is further arranged at the aperture, or is further arranged at a position close to the aperture; wherein the third lens includes an adjustable lens, and the adjustable lens is used to adjust the refractive power of the light according to the voltage to achieve the purpose of changing the curvature and thus changing the focusing distance. It has the advantages of millisecond-level automatic clear focus and low power consumption, and has no magnetic interference and no problems affected by gravity posture differences.

[0063] It should be noted that the third lens 300 is a lens with adjustable focal length, and the curvature radius and thickness of the third lens are changed by applying voltage, thereby changing the focal length of the lens.

[0064] In the embodiment of the present application, the third lens 300 can achieve clear focus at the entire focal length of 20 cm to 5 m, solving the virtual reality perspective analogy with the human eye function.

[0065] In the embodiment of the present application, the optical system may further include a filter element 800 and an imaging element 900. Figure 1 In the horizontal direction shown in FIG. 1 , the filter element 800 and the imaging element 900 are both located behind the seventh lens 700, and the filter element 800 and the imaging element 900 are sequentially arranged along the light transmission direction. The filter element 800 is used to select the required radiation band to optimize the imaging effect; the optimized image is finally projected on the imaging element 900.

[0066] The filter element 800 may include an infrared filter made of glass.

[0067] In the embodiment of the present application, the surface types of the first lens 100, the second lens 200, the fourth lens 400, the fifth lens 500, the sixth lens 600 and the seventh lens 700 are all aspherical surfaces, that is, the first lens 100, the second lens 200, the fourth lens 400, the fifth lens 500, the sixth lens 600 and the seventh lens 700 are all biconvex lenses, and both optical surfaces of the biconvex lenses are aspherical. Aspherical lenses have a better curvature radius and can maintain good aberration correction to obtain the required performance; at the same time, aspherical lenses have better sharpness and higher resolution.

[0068] Continue to refer Figure 1 In the above embodiment of the present application, the first lens 100 includes a first lens object side surface and a first lens image side surface, the first lens object side surface is a convex surface convex toward the object side, and the first lens image side surface is a concave surface convex toward the object side. The second lens 200 includes a second lens object side surface and a second lens image side surface, the second lens object side surface is a concave surface convex toward the object side, and the second lens image side surface is a convex surface convex toward the image side. The fourth lens 400 includes a fourth lens object side surface and a fourth lens image side surface, the fourth lens object side surface is a convex surface convex toward the object side, and the fourth lens image side surface is a convex surface convex toward the image side. The fifth lens 500 includes a fifth lens object-side surface and a fifth lens image-side surface, the fifth lens object-side surface is a concave surface convex toward the image side, and the image-side surface of the fifth lens is a concave surface convex toward the object side; the sixth lens 600 includes a sixth lens object-side surface and a sixth lens image-side surface, the sixth lens object-side surface is a convex surface convex toward the object side, and the image-side surface of the sixth lens is a convex surface convex toward the image side; the seventh lens 700 includes a seventh lens object-side surface and a seventh lens image-side surface, the seventh lens object-side surface is a concave surface convex toward the image side, and the image-side surface of the seventh lens is a concave surface convex toward the object side.

[0069] In the above embodiments of the present application, the first lens 100 , the second lens 200 , the fourth lens 400 , the fifth lens 500 , the sixth lens 600 and the seventh lens 700 are all made of plastic material.

[0070] In the embodiment of the present application, the surface type of the third lens 300 is a spherical surface type. The optical surface of the third lens includes a first surface, a second surface, a third surface and a fourth surface. The radius of curvature of the first surface is infinite (when the radius of curvature of a spherical surface tends to infinity, the spherical surface tends to a plane, that is, the plane can be regarded as a spherical surface with an infinite radius of curvature), the radius of curvature of the second surface is a variable, the radius of curvature of the third surface is a variable, and the radius of curvature of the fourth surface is infinite.

[0071] refer to Figure 2 , Figure 2 Parameters of the optical system provided in the embodiment of the present application Figure 1; Wherein, surface number 1 and surface number 2 refer to the two optical surfaces of the first lens 100, surface numbers 6, 7, 8, 9 refer to the four optical surfaces of the third lens 300, namely the first surface, the second surface, the third surface and the fourth surface, and the remaining surface numbers are similar and will not be repeated. It should be noted that, Figure 2 The structural parameters in also include the surface type, curvature radius, thickness, material of the lens, refractive index, dispersion, and focal length of the optical surface. It can be seen that the focal lengths of the first lens 100, the second lens 200, the fourth lens 400, the fifth lens 500, the sixth lens 600, and the seventh lens 700 are all quantitative, and the focal length of the third lens 300 (that is, the adjustable lens) is a variable.

[0072] In the above embodiment of the present application, the thickness of the first surface is 0.1 mm, the thickness of the second surface is 0.28 mm, the thickness of the third surface is 0.02 mm, and the thickness of the fourth surface is 0.1 mm.

[0073] The surface types of the filter element 800 and the imaging element 900 are both spherical surfaces.

[0074] The optical system of the embodiment of the present application also satisfies the following relationship:

[0075] F#≤2.2, F# is the aperture size of the optical system in the embodiment of the present application, and preferably, F# is 2.1.

[0076] FOV≥115°, FOV is the field of view angle of the optical system of the embodiment of the present application (the size of the field of view angle determines the field of view range of the optical instrument. The larger the field of view angle, the larger the field of view and the smaller the optical magnification). Preferably, the FOV is 120° to achieve a wide angle while ensuring the aperture size and increasing the amount of light entering.

[0077] TTL / IH≤2.14, TTL is the total length of the lens group in the optical system of the embodiment of the present application, that is, the length of the lens; IH is the diagonal full field of view image height. Among them, the diagonal full field of view image height and the camera module optical CRA (chiefray angle) image height are matched with the 8M chip to achieve a higher resolution and adapt to the current screen resolution. Preferably, TTL is 10mm.

[0078] -2.6≤TTL / f1≤-1.8, f1 is the focal length of the first lens 100, preferably, f1 is -4.58 mm.

[0079] 1.0≤TTL / f2≤1.6, f2 is the focal length of the second lens 200, and preferably, f2 is 7.768 mm.

[0080] 2.4≤TTL / f4≤3.0, f4 is the focal length of the fourth lens 400, and preferably, f4 is 3.739 mm.

[0081] -2.1≤TTL / f5≤-1.5, f5 is the focal length of the fifth lens 500, preferably, f5 is -5.56 mm.

[0082] 2.6≤TTL / f6≤3.4, f6 is the focal length of the sixth lens 600, and preferably, f6 is 3.307 mm.

[0083] -2.6≤TTL / f7≤-2, f7 is the focal length of the seventh lens 700, and preferably, f7 is -4.359 mm.

[0084] The optical system obtained by the above parameters and relationship has excellent aberration performance in the entire focal length and can achieve a large field of view and a large exit pupil diameter.

[0085] The following will analyze and illustrate the image quality of the optical system of the present application embodiment using six embodiments:

[0086] Image quality refers to the imaging quality of a lens, and is used to evaluate the imaging quality of a lens. Modulation transfer function (MTF) and distortion are two important parameters used to evaluate image quality. The image obtained by the lens imaging is "blurred" relative to the real object, and the contrast is reduced. MTF is usually used to measure the imaging quality. Distortion is caused by the optical structure and imaging characteristics of the lens. Distortion is caused by the inconsistent magnification of different parts on the image plane, which is a magnification aberration.

[0087] refer to Figure 2-Figure 4 , Figure 3 Parameters of the optical system provided in the embodiment of the present application Figure 2 , Figure 4 Parameters of the optical system provided in the embodiment of the present application Figure 3 ;in, Figure 3 The horizontal axis in is Figure 2 For example, surface number 1 refers to the aspheric surface of the first lens, and surface number 12 refers to the aspheric surface of the fifth lens; Figure 3 K in is the cone coefficient of each face, Figure 3 A4, A6, A8, A10, A12, A14, and A16 are the aspheric coefficients of each surface.

[0088] In the following six embodiments, the following parameters remain consistent: the thickness of the first surface of the third lens 300 is 0.1 mm, the thickness of the second surface is 0.28 mm, the thickness of the third surface is 0.02 mm, and the thickness of the fourth surface is 0.1 mm; the radius of curvature of the first surface is infinite, the radius of curvature of the second surface is variable, the radius of curvature of the third surface is variable, and the radius of curvature of the fourth surface is infinite.

[0089] In the first embodiment, the curvature radii of the second surface and the third surface of the third lens are both -31.78354 mm, and the thickness of the object to be photographed is 1500 mm.

[0090] In the second embodiment, the curvature radii of the second surface and the third surface of the third lens are both infinite, and the thickness of the object to be photographed is 200 mm.

[0091] In the third embodiment, the curvature radii of the second surface and the third surface of the third lens are both 28.08564 mm, and the thickness of the object to be photographed is 400 mm.

[0092] In the fourth embodiment, the curvature radii of the second surface and the third surface of the third lens are both -32.1656 mm, and the thickness of the object to be photographed is 800 mm.

[0093] In the fifth embodiment, the curvature radii of the second surface and the third surface of the third lens are both -67.36288 mm, and the thickness of the object to be photographed is 2000 mm.

[0094] In the sixth embodiment, the curvature radii of the second surface and the third surface of the third lens are both -31.34893 mm, and the thickness of the object is 5000 mm.

[0095] refer to Figure 5-Figure 16 , Figure 5 This is a schematic diagram of the optical transfer function of the optical system provided in Example 1 of the present application. Figure 6 A schematic diagram of optical distortion of an optical system provided in Embodiment 1 of the present application; Figure 7 A schematic diagram of an optical transfer function of an optical system provided in Embodiment 2 of the present application, Figure 8 A schematic diagram of optical distortion of an optical system provided in Embodiment 2 of the present application; Fig. 9 This is a schematic diagram of the optical transfer function of the optical system provided in Example 3 of the present application. Fig.10 A schematic diagram of optical distortion of an optical system provided in Embodiment 3 of the present application; Fig.11 This is a schematic diagram of the optical transfer function of the optical system provided in the fourth embodiment of the present application. Fig.12 A schematic diagram of optical distortion of an optical system provided in Embodiment 4 of the present application; Fig.13 This is a schematic diagram of the optical transfer function of the optical system provided in Example 5 of the present application, Fig.14A schematic diagram of optical distortion of an optical system provided in Embodiment 5 of the present application; Fig.15 This is a schematic diagram of the optical transfer function of the optical system provided in Example 6 of the present application, Fig.16 A schematic diagram of the optical distortion of the optical system provided in Example 6 of the present application.

[0096] Among them, the optical transfer function (OTF) is a complex variable related to the spatial frequency, and its modulus is the modulation transfer function (MFT); it can be seen that the aberration performance at the entire focal length is excellent.

[0097] An embodiment of the present application also provides a virtual reality device, which includes the optical system described above.

[0098] In summary, the embodiments of the present application provide an optical system and a virtual reality device, wherein the optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens sequentially arranged along the direction of light transmission, and the optical system also includes an aperture, and the third lens is further arranged at the aperture, or is further arranged at a position close to the aperture; wherein the third lens includes an adjustable lens, and the adjustable lens is used to adjust the refractive power of the light according to the voltage, so as to achieve the purpose of changing the curvature and thus changing the focusing distance, and has the advantages of millisecond-level automatic clear focusing, and has low power consumption, no magnetic interference, and no problems affected by gravity posture differences.

[0099] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0100] It should be noted that the phrases "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments", etc. mentioned in the specification indicate that the described embodiments may include certain features, structures or characteristics, but not every embodiment may include the certain features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing certain features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments, whether explicitly or not explicitly described.

[0101] In general, terms should be understood, at least in part, by the context in which they are used. For example, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in a singular sense, or may be used to describe a combination of features, structures, or characteristics in a plural sense, depending, at least in part, on the context. Similarly, terms such as "a," "an," or "the" may also be understood to convey singular usage or to convey plural usage, depending, at least in part, on the context.

[0102] It should be easily understood that “on,” “above,” and “over” in the present disclosure should be interpreted in the broadest manner, so that “on” not only means “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “above” or “over” not only includes the meaning of “above” or “over,” but also may include the meaning of “above” or “over something” with no intervening features or layers therebetween (i.e., directly on something).

[0103] In addition, spatially relative terms, such as "below," "below," "beneath," "above," "above," etc., may be used herein for ease of description to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An optical system, characterized in that: It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged along the light transmission direction, a total of seven lenses; The optical system further comprises an aperture stop, wherein the aperture stop is located between the second lens and the third lens; Wherein, the third lens comprises an adjustable lens, and the adjustable lens is used to adjust the diopter of the light according to the voltage; The first lens comprises a first lens object side surface and a first lens image side surface, the first lens object side surface is a convex surface convex toward the object, and the first lens image side surface is a concave surface convex toward the object; The second lens comprises a second lens object side surface and a second lens image side surface, the second lens object side surface is a concave surface convex toward the image side, and the second lens image side surface is a convex surface convex toward the image side; The fourth lens comprises a fourth lens object side surface and a fourth lens image side surface, the fourth lens object side surface is a convex surface convex toward the object side, and the fourth lens image side surface is a convex surface convex toward the image side; The fifth lens comprises a fifth lens object side surface and a fifth lens image side surface, the fifth lens object side surface is a concave surface convex toward the image side, and the fifth lens image side surface is a concave surface convex toward the object side; The sixth lens comprises a sixth lens object side surface and a sixth lens image side surface, the sixth lens object side surface is a convex surface convex toward the object side, and the sixth lens image side surface is a convex surface convex toward the image side; The seventh lens comprises a seventh lens object side surface and a seventh lens image side surface. The object side surface of the seventh lens is a concave surface convex toward the image side, and the image side surface of the seventh lens is a concave surface convex toward the object side.

2. The optical system according to claim 1, characterized in that The optical system further comprises a filter element and an imaging element. In the light transmission direction, the filter element and the imaging element are both located behind the seventh lens, and the filter element and the imaging element are arranged in sequence.

3. The optical system according to claim 2, characterized in that The surfaces of the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all aspherical, and the surfaces of the third lens, the filter element and the imaging element are all spherical.

4. The optical system according to claim 1, characterized in that The optical system satisfies the following relationship: F#≤2.2； FOV ≥ 115°; TTL / IH≤2.14; -2.6≤TTL / f1≤-1.8; 1.0≤TTL / f2≤1.6; 2.4≤TTL / f4≤3.0; -2.1≤TTL / f5≤-1.5; 2.6≤TTL / f6≤3.4; -2.6≤TTL / f7≤-2; Among them, F# is the aperture of the optical system, FOV is the field of view of the optical system, TTL is the total length of the lens group in the optical system, IH is the full field of view image height of the diagonal, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

5. The optical system according to claim 1, characterized in that The optical surface of the third lens includes a first surface, a second surface, a third surface and a fourth surface, the curvature radius of the first surface is infinite, the curvature radius of the second surface is variable, the curvature radius of the third surface is variable, and the curvature radius of the fourth surface is infinite.

6. The optical system according to claim 5, characterized in that The thickness of the first surface is 0.1 mm, the thickness of the second surface is 0.28 mm, the thickness of the third surface is 0.02 mm, and the thickness of the fourth surface is 0.1 mm; wherein the thickness of the first surface is the distance between the first surface and the second surface on the optical axis, the thickness of the second surface is the distance between the second surface and the third surface on the optical axis, the thickness of the third surface is the distance between the third surface and the fourth surface on the optical axis, and the thickness of the fourth surface is the distance between the fourth surface and the object side of the fourth lens on the optical axis.

7. The optical system according to claim 1, characterized in that The first lens, the second lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all made of plastic material.

8. The optical system according to claim 2, characterized in that The filter element comprises an infrared filter.

9. A virtual reality device, characterized in that: The optical system comprises any one of claims 1 to 8.

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