Optical lens and near-eye display device

Abstract

The present invention provides an optical lens and a near-eye display device, which include, in sequence from the entrance pupil side of the human eye to the image source side along the reverse direction of light transmission: a first lens with negative optical power, whose light-emitting surface is concave at the near optical axis and whose light-entering surface is concave; a second lens with positive optical power, whose light-emitting surface is convex and whose light-entering surface is concave; a third lens with positive optical power, whose light-emitting surface is convex and whose light-entering surface is convex; a fourth lens with negative optical power, whose light-emitting surface is concave and whose light-entering surface is concave; a fifth lens with positive optical power, whose light-emitting surface is convex and whose light-entering surface is concave; a sixth lens with positive optical power, whose light-emitting surface is convex and whose light-entering surface is concave; a seventh lens with positive optical power has positive optical power, whose light-emitting surface is convex and whose light-entering surface is concave. The distance range between the light-entering surface of the seventh lens and the image source on the optical axis is adjustable. The optical lens provided by the present invention has the advantage of excellent imaging quality.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and in particular to an optical lens and a near-eye display device. Background Art

[0002] With the development of virtual reality (VR) technology, the forms and types of virtual reality devices are becoming increasingly diverse, and the application fields are also constantly expanding. It has been widely used in many fields such as games, social networking, education, and medical care. Current near-eye display devices such as VR usually transmit and magnify the display screen in the device through an optical lens, and then transmit the output image to the human eye. Therefore, the human eye receives the magnified virtual image of the display screen, thereby achieving the purpose of large-screen viewing through near-eye display devices such as VR.

[0003] In order to provide users with an excellent sensory experience, VR and other near-eye display devices need to have a larger field of view, a larger eye movement range, and higher-quality imaging. At the same time, in order to meet the needs of users with different degrees of myopia or hyperopia, they also need to have adjustable diopter. However, the optical lenses currently used in VR devices still have shortcomings such as large distortion, poor diopter adjustment, and poor imaging quality, which cannot meet market demand well. Summary of the invention

[0004] In view of the above problems, the object of the present invention is to provide an optical lens having the advantages of adjustable diopter and excellent imaging quality.

[0005] The technical solution adopted by the present invention is:

[0006] An optical lens, the optical lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens in sequence from the entrance pupil side of a human eye to the image source side along the reverse direction of light transmission; the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens each comprise a light entrance surface and a light exit surface, the light entrance surface and the light exit surface are arranged oppositely on the surface of each lens; the first lens has a negative optical power, the light exit surface of the first lens is a concave surface at the near optical axis, and the light entrance surface of the first lens is a concave surface;

[0007] The second lens has positive power, a light exiting surface of the second lens is a convex surface, and a light incident surface of the second lens is a concave surface;

[0008] The third lens has positive power, the light exiting surface of the third lens is a convex surface, and the light incident surface of the third lens is a convex surface;

[0009] The fourth lens has negative optical power, the light exiting surface of the fourth lens is a concave surface, and the light incident surface of the fourth lens is a concave surface;

[0010] The fifth lens has positive refractive power, the light exiting surface of the fifth lens is a convex surface, and the light incident surface of the fifth lens is a concave surface;

[0011] The sixth lens has positive power, the light exiting surface of the sixth lens is a convex surface, and the light incident surface of the sixth lens is a concave surface;

[0012] The seventh lens has positive power, the light exiting surface of the seventh lens is a convex surface, and the light incident surface of the seventh lens is a concave surface;

[0013] The range of the distance CTw between the light incident surface of the seventh lens and the image source on the optical axis is adjustable;

[0014] The exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.6 <ED / f<0.7。

[0015] The present invention also provides a near-eye display device, which includes, in sequence along the direction of light signal transmission: an image source and the above-mentioned optical lens; the image source is used to emit a light signal, and the light signal includes image information; the optical lens is arranged in the light emitting direction of the image source, and the seventh lens is arranged closer to the image source than the first lens, and the optical lens is used to modulate the light signal emitted by the image source and transmit it to the human eye.

[0016] Compared with the prior art, the optical lens provided by the present invention has a larger field of view angle through a specific surface shape setting and reasonable optical focal length distribution. The larger field of view angle can provide a wide field of view display effect, giving users a better experience; at the same time, the optical lens also has a larger image surface and higher resolution, which can match a large-size image source to achieve high-definition imaging and improve imaging quality. The diopter adjustment from -8D to +5D can be achieved by adjusting the spatial spacing distance between the entire lens group and the image source on the optical axis, and all have high imaging quality, bringing users an excellent sensory experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0018] Figure 1 It is a schematic diagram of the structure of a near-eye display device provided in an embodiment of the present invention.

[0019] Figure 2 Schematic diagram of the structure of the optical lens provided in Example 1 of the present invention.

[0020] Figure 3 This is a graph showing the F-Theta distortion of the optical lens provided in Example 1 of the present invention.

[0021] Figure 4 The vertical axis chromatic aberration curve of the optical lens provided in Example 1 of the present invention is shown in FIG.

[0022] Figure 5 This is a relative illumination diagram of the optical lens provided in Example 1 of the present invention.

[0023] Figure 6 Schematic diagram of the structure of the optical lens provided in Example 2 of the present invention.

[0024] Figure 7 This is an F-Theta distortion curve of the optical lens provided in Example 2 of the present invention.

[0025] Figure 8 This is a vertical axis chromatic aberration curve diagram of the optical lens provided in Example 2 of the present invention.

[0026] Fig. 9 This is a relative illumination diagram of the optical lens provided in Example 2 of the present invention.

[0027] Fig.10 Schematic diagram of the structure of the optical lens provided in Example 3 of the present invention.

[0028] Fig.11 This is an F-Theta distortion curve of the optical lens provided in Example 3 of the present invention.

[0029] Fig.12 The vertical axis chromatic aberration curve of the optical lens provided in Example 3 of the present invention is shown.

[0030] Fig.13 This is a relative illumination diagram of the optical lens provided in Example 3 of the present invention.

[0031] Fig.14 This is a schematic diagram of the optical path of the near-eye display device provided in Example 4 of the present invention.

[0032] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0033] 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 the 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.

[0034] 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 invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0035] 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.

[0036] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the convex position is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region.

[0037] 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.

[0038] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0040] The present invention provides an optical lens, which is used to modulate the optical signal emitted by an image source and transmit it to the entrance pupil side of the human eye. The optical lens is arranged in the light-emitting direction of the image source, that is, the emission surface of the image source is the light-emitting side of the optical signal. Along the reverse direction of the light transmission (i.e., from the entrance pupil side of the human eye to the image source surface), it sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, and there is an air gap between any two adjacent lenses. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens each include an incident light surface and an exit light surface, and the incident light surface and the exit light surface are oppositely arranged on the surface of each lens. It can be understood that the surface of each lens close to the image source is called the incident light surface of the lens, and the surface of each lens close to the entrance pupil side of the human eye is called the exit light surface of the lens.

[0041] In some embodiments, the first lens has a negative optical power, the exit light surface of the first lens is concave near the optical axis, and the incident light surface of the first lens is concave. The second lens has a positive optical power, the exit light surface of the second lens is convex, and the incident light surface of the second lens is concave. The third lens has a positive optical power, the exit light surface of the third lens is convex, and the incident light surface of the third lens is convex. The fourth lens has a negative optical power, the exit light surface of the fourth lens is concave, and the incident light surface of the fourth lens is concave. The fifth lens has a positive optical power, the exit light surface of the fifth lens is convex, and the incident light surface of the fifth lens is concave. The sixth lens has a positive optical power, the exit light surface of the sixth lens is convex, and the incident light surface of the sixth lens is concave. The seventh lens has a positive optical power, the exit light surface of the seventh lens is convex, and the incident light surface of the seventh lens is concave.

[0042] To meet the wearing needs of users with different refractive degrees, the air interval CTw (i.e., the distance between the incident light surface of the seventh lens and the image source on the optical axis) between the entire lens group (composed of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens) and the image source can be dynamically adjusted to achieve the adjustment of the optical lens between different diopters, so as to well meet the wearing needs of users with different refractive degrees. More specifically, the adjustment range of the distance CTw between the incident light surface of the seventh lens and the image source side on the optical axis satisfies: 4mm < CTw < 10mm. Meeting the above conditions, by setting a large air distance between the optical lens and the image source, the light rays emitted from the image source side can have a large refraction space, and at the same time, it is convenient to finely adjust the axial distance between the entire optical lens and the image source, so that users with different myopia or hyperopia degrees can wear it with a relatively clear picture, improving the sensory experience of different users. In this application, the optical lens can achieve adjustable diopters from -800 to 500 degrees (-8D to 5D), so that users with different myopia or hyperopia degrees can wear it with a good sensory experience.

[0043] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.85 < TTL / f < 2.3. Meeting the above conditions is conducive to the optical lens having a relatively compact structure, while enabling the lens to have a longer focal length, being able to better present larger local details, and improving the picture quality.

[0044] In some embodiments, the exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.6 < ED / f < 0.7. The exit pupil distance ED represents the distance on the optical axis from the entrance pupil side of the human eye to the light-emitting surface of the first lens. Meeting the above conditions can ensure a large entrance pupil distance while achieving a large field of view angle, reduce the dizziness when the human eye wears it, and improve the sensory experience.

[0045] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -5 < f1 / f < -3; the curvature radius R1 of the light-emitting surface of the first lens and the curvature radius R2 of the light-incident surface of the first lens satisfy: -0.4 < R1 / R2 < -0.1. Meeting the above conditions can increase the divergence degree of light, better diverge the light into the human eye observation area, and thus can provide a wide field of view display effect and improve the user's immersion.

[0046] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.8 < f2 / f < 2.5; the curvature radius R3 of the light-emitting surface of the second lens and the curvature radius R4 of the light-incident surface of the second lens satisfy: 0.3 < R3 / R4 < 0.4. Meeting the above conditions can further converge the light, make the light enter the system at a relatively gentle angle of view, reduce the correction difficulty of aberration and distortion, and improve the overall imaging quality.

[0047] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.5 < f3 / f < 2.5; the curvature radius R5 of the light-emitting surface of the third lens and the curvature radius R6 of the light-incident surface of the third lens satisfy: -0.5 < R5 / R6 < -0.04. Meeting the above conditions is conducive to converging the light emitted from the image source side, reducing the divergence degree of the light, and thus entering the human eye at an angle close to parallel, ensuring a large field of view angle while improving the overall imaging quality.

[0048] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -0.8 < f4 / f < -0.2; the curvature radius R7 of the light-emitting surface of the fourth lens and the curvature radius R8 of the light-incident surface of the fourth lens satisfy: -1.5 < R7 / R8 < -0.2. Meeting the above conditions, by setting the fourth lens to have a large negative refractive power, the light emitted from the image source side can be diverged to a large extent to increase the area of the projected virtual image and provide a better immersion experience for the user.

[0049] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.5 < f5 / f < 2; the radius of curvature R9 of the light-emitting surface of the fifth lens and the radius of curvature R10 of the light-incident surface of the fifth lens satisfy: 0.5 < R9 / R10 < 1.2. Meeting the above conditions is conducive to the convergence of light rays, enabling the light rays emitted from the image source side to smoothly enter the rear optical system, reducing the correction difficulty of various aberrations, and better achieving high-quality imaging of the lens.

[0050] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.6 < f6 / f < 1; the radius of curvature R11 of the light-emitting surface of the sixth lens and the radius of curvature R12 of the light-incident surface of the sixth lens satisfy: 0 < R11 / R12 < 0.2. Meeting the above conditions can effectively converge the light rays emitted from the image source side, reduce the correction difficulty of aberrations and distortions, and improve the overall imaging quality.

[0051] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 0.85 < f7 / f < 1.5; the radius of curvature R13 of the light-emitting surface of the seventh lens and the radius of curvature R14 of the light-incident surface of the seventh lens satisfy: 0.6 < R13 / R14 < 1.2. Meeting the above conditions, for the light rays emitted from the image source side, the seventh lens close to the image source side is set with a relatively large positive refractive power, which can converge the light rays emitted from the image source side to a certain extent, ensure that the light rays in the edge field of view can effectively enter the entire lens, make the system have a relatively high relative illuminance, improve the image quality at the edge, and provide a good immersion experience for users with different myopia or hyperopia degrees.

[0052] In some embodiments, the combined focal length fa of the first lens and the second lens and the combined focal length fb of the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: 3 < fa / fb < 4.5. Meeting the above conditions, by reasonably setting the focal length relationship between the front and rear lens groups, the light rays enter the human eye at a relatively gentle angle, reducing the correction difficulty of aberrations and distortions, improving the imaging quality, and enabling users with different myopia or hyperopia degrees to have a better sensory experience when wearing.

[0053] In some embodiments, the sum of the central thicknesses ∑CT of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens and the overall optical length TTL of the optical lens satisfy: 0.65 < ∑CT / TTL < 0.75. Meeting the above conditions can, on the one hand, effectively control the overall volume of the optical lens, provide sufficient and compact arrangement space between the lenses, thereby enabling the optical lens to achieve a miniaturized design. On the other hand, it can provide sufficient deflection space for light rays within each lens, thus enabling reasonable control of the light ray deflection of the optical lens, facilitating reduction of the light ray deflection angle, and further facilitating balancing of aberration ranges such as distortion generated by each lens, and improving the overall imaging quality.

[0054] In some embodiments, the length IH of the display area of the image source that the optical lens can match and the effective focal length f of the optical lens satisfy: 1.2 < IH / f < 1.32. Meeting the above conditions is beneficial for achieving the long focal length performance of the lens, enabling better presentation of larger local details, making the picture more concentrated and compact, thereby meeting the visual experience of the human eye; at the same time, it also enables the optical lens to match a larger-sized image source for high-definition imaging, bringing an excellent sensory experience to users.

[0055] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -2.5 < f1 / f2 < -1.5. Meeting the above conditions, by reasonably allocating the focal lengths of the first lens and the second lens, the degree of light ray turning can be effectively reduced, enabling the lens to have a larger field of view angle and long focal length performance, thereby achieving an effect close to the human eye's field of view.

[0056] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -6 < f3 / f4 < -2.5. Meeting the above conditions can reduce the degree of convergence of marginal light rays, which is beneficial for correcting the distortion of the optical lens and improving the imaging quality of the lens's marginal field of view.

[0057] In some embodiments, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: 0.5 < f5 / f6 < 2.5. Meeting the above conditions is beneficial for correcting the aberration of the optical lens, improving the imaging quality, and enabling users with different degrees of myopia or hyperopia to have a better sensory experience when wearing.

[0058] In some embodiments, the exit pupil distance ED of the optical lens and the overall optical length TTL of the optical lens satisfy: 0.3 < ED / TTL < 0.32. Meeting the above conditions ensures that the optical lens has an appropriate exit pupil distance, effectively reducing the overall optical length of the lens while meeting the human eye's observation range.

[0059] In some embodiments, the combined focal length fa of the first lens and the second lens and the effective focal length f of the optical lens satisfy: 3.5 < fa / f < 5; the combined focal length fb of the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens and the effective focal length f of the optical lens satisfy: 1 < fb / f < 1.5. Meeting the above conditions is beneficial to the smooth transition of light, and at the same time corrects various aberrations of the optical lens, improving the imaging quality of the optical lens.

[0060] In some embodiments, the optical lens satisfies the conditional formula: 35mm < TTL < 42mm, 18mm < f < 20mm; 65° < FOV < 75°, 20mm < IH < 25mm; where TTL represents the overall optical length of the optical lens, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, and IH represents the display area length of the image source that the optical lens can match. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention has the advantages of at least a small overall length and a large field of view angle.

[0061] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. On the other hand, when the lens material is glass, the geometric chromatic aberration of the optical lens can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt an all-plastic lens structure, which not only enables the lens to have excellent imaging performance, but also makes the structure of the lens relatively compact, and can better achieve the balance of miniaturization and high image quality of the lens.

[0062] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens of the present invention can all adopt aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens.

[0063] In each embodiment of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0064] ;

[0065] Among them, z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the surface vertex, K is the quadratic surface coefficient, B, C, D, E, F, G, and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients respectively.

[0066] In addition, the present invention also provides a near-eye display device, which includes, in sequence along the direction of light signal transmission: an image source, the above-mentioned optical lens; the image source is used to emit a light signal, and the light signal includes image information; the optical lens is arranged in the light emitting direction of the image source, and the seventh lens is arranged closer to the image source than the first lens, and the optical lens is used to modulate the light signal emitted by the image source and transmit it to the human eye.

[0067] The present invention is further described below in multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different. For specific differences, please refer to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications that do not deviate from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0068] Example 1

[0069] See also Figure 1 , which is a schematic diagram of the structure of a near-eye display device 400 provided in an embodiment of the present invention, please refer to Figure 2 , which is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention, is used to modulate the optical signal emitted by the image source 10 and transmit it to the entrance pupil side of the human eye. The optical lens 100 is arranged in the light emitting direction of the image source 10, that is, the emitting surface of the image source 10 is the light emitting side of the optical signal. Figure 2 It can be known that the optical lens 100 is sequentially provided with the following components along the opposite direction of light transmission (i.e., from the entrance pupil side of the human eye to the image source side): the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7. The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 each include a light entrance surface and a light exit surface, and the light entrance surface and the light exit surface are arranged on the surface of each lens relatively. It can be understood that the surface of each lens close to the image source 10 is called the light entrance surface of the lens, and the surface of each lens close to the entrance pupil side of the human eye is called the light exit surface of the lens. It should be noted that the entrance pupil position of the human eye is the aperture ST of the optical lens 100.

[0070] The first lens L1 has negative optical power, a light exiting surface S1 of the first lens is a concave surface at the near optical axis, and a light incident surface S2 of the first lens is a concave surface;

[0071] The second lens L2 has positive refractive power, a light exiting surface S3 of the second lens is a convex surface, and a light incident surface S4 of the second lens is a concave surface;

[0072] The third lens L3 has positive refractive power, a light exiting surface S5 of the third lens is a convex surface, and a light incident surface S6 of the third lens is a convex surface;

[0073] The fourth lens L4 has negative optical power, a light exiting surface S7 of the fourth lens is a concave surface, and a light incident surface S8 of the fourth lens is a concave surface;

[0074] The fifth lens L5 has positive refractive power, a light exiting surface S9 of the fifth lens L5 is a convex surface, and a light incident surface S10 of the fifth lens L5 is a concave surface;

[0075] The sixth lens L6 has positive refractive power, a light exiting surface S11 of the sixth lens L6 is a convex surface, and a light incident surface S12 of the sixth lens L6 is a concave surface;

[0076] The seventh lens L7 has positive refractive power. The light-emitting surface S13 of the seventh lens L7 is a convex surface, and the light-incident surface S14 of the seventh lens L7 is a concave surface.

[0077] In order to better realize a small lens volume and reduce the cost, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all plastic aspherical lenses.

[0078] In order to meet the wearing needs of users with different refractive powers, the air spacing CTw on the optical axis (the distance between the light incident surface of the seventh lens L7 and the image source 10 on the optical axis) between the entire lens group (consisting of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7) and the image source 10 can be dynamically adjusted to achieve adjustment of the optical lens between different refractive powers, thereby being able to well meet the wearing needs of users with different refractive powers.

[0079] Specifically, in this embodiment, the adjustment range of the distance CTw between the light incident surface of the seventh lens and the image source side on the optical axis is 4.586~9.046mm, which can achieve -800~500 degrees (-8D~5D) of adjustable diopter, so that users with different myopia or hyperopia degrees can have a good sensory experience when wearing it. Figure 2, which is a schematic diagram of the structure of the optical lens 100 when the diopter is 0D (0°), and the CTw is 7.253mm at this time; when the CTw is 4.586mm, the diopter of the optical lens 100 is -8D (-800°); when the CTw is 9.046mm, the diopter of the optical lens 100 is 5D (500°).

[0080] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0081] Table 1-1

[0082]

[0083] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0084] Table 1-2

[0085]

[0086] The corresponding parameters of the optical lens 100 in Example 1 under different refractive power states are shown in Tables 1-3.

[0087] Table 1-3

[0088]

[0089] Please refer to Figure 3 , which is a graph of the F-Theta distortion of the optical lens 100, wherein the horizontal axis represents the F-Theta distortion percentage and the vertical axis represents the field of view angle (unit: degree). Figure 3 It can be seen that the F-Theta distortion value at the image height received by the user's eyes is controlled within 0~5%, indicating that the distortion of the optical lens 100 is well corrected.

[0090] Please refer to Figure 4 , which is a vertical axis chromatic aberration curve of the optical lens 100, represents the chromatic aberration of each wavelength relative to the central wavelength (0.550 μm) at the image height received by the user's eyes, the horizontal axis represents the vertical axis chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view. Figure 4 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -5~20μm, indicating that the chromatic aberration of the optical lens 100 is well corrected.

[0091] Please refer to Figure 5, which is a relative illumination curve of the optical lens 100, indicating the relative illumination value at the image height received by the user's eyes, the horizontal axis indicates the field angle (unit: °), and the vertical axis indicates the relative illumination value (unit: %). It can be seen from the figure that the relative illumination value of the optical lens at the edge of the field of view is still greater than 70%, indicating that the optical lens 100 has good relative illumination.

[0092] from Figure 3 , Figure 4 , Figure 5 It can be seen that the aberration of the optical lens 100 is well balanced and has good imaging quality.

[0093] Example 2

[0094] See also Figure 6 , which is a schematic diagram of the structure of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main differences between this embodiment and Example 1 are: the optical parameters such as the curvature radius of each lens surface and the lens thickness are different; the optical parameters corresponding to different refractive powers are different, and the adjustment range of the distance CTw between the light incident surface and the image source side on the optical axis of the seventh lens is 5.14~9.578mm.

[0095] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0096] Table 2-1

[0097]

[0098] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0099] Table 2-2

[0100]

[0101] The corresponding parameters of the optical lens 200 in Example 2 under different refractive power states are shown in Table 2-3.

[0102] Table 2-3

[0103]

[0104] Please refer to Figure 7 , which is a graph of the F-Theta distortion of the optical lens 200, wherein the horizontal axis represents the F-Theta distortion percentage and the vertical axis represents the field of view angle (unit: degree). Figure 7 It can be seen that the F-Theta distortion value at the image height received by the user's eyes is controlled within ±2%, indicating that the distortion of the optical lens 200 is well corrected.

[0105] Please refer to Figure 8 , which is a vertical axis chromatic aberration curve of the optical lens 200, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.550 μm) at the image height received by the user's eyes, the horizontal axis represents the vertical axis chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view. Figure 8 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -7~20μm, indicating that the chromatic aberration of the optical lens 200 is well corrected.

[0106] Please refer to Fig. 9 , which is a relative illumination curve of the optical lens 200, which indicates the relative illumination value at the image height received by the user's eyes, the horizontal axis indicates the field of view angle (unit: °), and the vertical axis indicates the relative illumination value (unit: %). It can be seen from the figure that the relative illumination value of the optical lens at the edge of the field of view is still greater than 70%, indicating that the optical lens 200 has good relative illumination.

[0107] from Figure 7 , Figure 8 , Fig. 9 It can be seen that the aberration of the optical lens 200 is well balanced and has good imaging quality.

[0108] Example 3

[0109] See also Fig.10 , which is a schematic diagram of the structure of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main differences between this embodiment and Example 1 are: the optical parameters such as the curvature radius of each lens surface and the lens thickness are different; the optical parameters corresponding to different refractive powers are different, and the adjustment range of the distance CTw between the light incident surface of the seventh lens and the image source side on the optical axis is 5.34~9.946mm.

[0110] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0111] Table 3-1

[0112]

[0113] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0114] Table 3-2

[0115]

[0116] The corresponding parameters of the optical lens 300 in Example 3 under different refractive power states are shown in Table 3-3.

[0117] Table 3-3

[0118]

[0119] Please refer to Fig.11 , which is a F-Theta distortion curve of the optical lens 300, wherein the horizontal axis represents the F-Theta distortion percentage and the vertical axis represents the field of view angle (unit: degree). Fig.11 It can be seen that the F-Theta distortion value at the image height received by the user's eyes is controlled within ±1%, indicating that the distortion of the optical lens 300 is well corrected.

[0120] Please refer to Fig.12 , which is a vertical axis chromatic aberration curve of the optical lens 300, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.550 μm) at the image height received by the user's eyes, the horizontal axis represents the vertical axis chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field of view. Fig.12 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -10~25μm, indicating that the chromatic aberration of the optical lens 300 is well corrected.

[0121] Please refer to Fig.13 , which is a relative illumination curve of the optical lens 300, indicating the relative illumination value at the image height received by the user's eyes, the horizontal axis indicates the field of view angle (unit: °), and the vertical axis indicates the relative illumination value (unit: %). It can be seen from the figure that the relative illumination value of the optical lens at the edge of the field of view is still greater than 70%, indicating that the optical lens 300 has good relative illumination.

[0122] from Fig.11 , Fig.12 , Fig.13 It can be seen that the aberration of the optical lens 300 is well balanced and has good imaging quality.

[0123] Please refer to Table 4, which shows the optical characteristics of the optical lenses provided in the above three embodiments when the diopter is 0D (0°), including the effective focal length f, total optical length TTL, aperture value Fno, maximum field of view FOV, back focal length BFL, entrance pupil diameter EPD, exit pupil distance ED, and display area length IH of the image source that the optical lens can match, and the numerical value corresponding to each conditional expression in each embodiment.

[0124] Table 4

[0125]

[0126] In summary, the optical lens provided by the present invention has at least the following advantages:

[0127] (1) Through specific surface shape settings and reasonable optical focal length distribution, the optical lens has a larger field of view angle. The larger field of view angle can provide a wide field of view display effect, giving users a better experience.

[0128] (2) The optical lens also has a larger image surface, higher illumination (relative illumination is within 70%) and higher resolution, which can match large-size image sources to achieve high-definition imaging, improve imaging quality, and bring users an excellent sensory experience.

[0129] (3) Different diopter adjustments can be achieved by adjusting the spatial distance between the lens group and the image source on the optical axis. A wide range of diopter adjustments (-8D to +5D) can be achieved, and the imaging quality is high, which can meet the needs of different myopic users. At the same time, it has a large exit pupil distance (ED>12mm), which can provide users with a better experience.

[0130] Example 4

[0131] See also Fig.14 , which is a schematic diagram of an optical path in a near-eye display device 400 provided in an embodiment of the present invention, the near-eye display device 400 includes an image source 10, an optical lens (such as optical lens 100) in any of the aforementioned embodiments of the present application, and the optical lens 100 is located between the human eye 20 and the image source 10. The image information emitted from the image source 10 enters the human eye 20 through the optical lens 100 to form an image, and a high-definition magnified virtual image can be observed in the human eye 20, which has an extremely realistic sensory experience.

[0132] The image source 10 is used to emit a light signal, and the light signal includes image information. Specifically, the image source 10 can be one of a display screen such as Micro LED, OLED, LCD, LCOS, M-OLED, etc., and can provide high-definition image information for the optical lens 100.

[0133] The optical lens 100 is arranged in the light emitting direction of the image source 10 , and the seventh lens in the optical lens 100 is arranged closer to the image source 10 than the first lens. The optical lens 100 is used to modulate the light signal emitted by the image source 10 and transmit it to the human eye 20 .

[0134] The near-eye display device 400 can be VR glasses, VR helmets, head-mounted display devices, etc. By adjusting the distance between the lens and the image source side, the diopter can be adjusted (-8D~5D), so that users with different degrees of myopia or hyperopia can have a better wearing experience. Since the above-mentioned optical lens has a large field of view, the large field of view can provide a wide field of view display effect, improve the user's sense of immersion, and thus bring a better experience to the user. At the same time, the optical lens also has a large image surface and a high resolution. The light signal image modulated by the optical lens is bright and clear, the effect is better, and the picture projected to the human eye is clearer. Therefore, the near-eye display device equipped with the optical lens has at least the characteristics of a wide field of view and high image quality, which can effectively improve the user's visual experience and comfort.

[0135] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0136] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical lens, characterized in that: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are sequentially included from the entrance pupil side of the human eye to the image source side along the reverse direction of light transmission; the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens each include a light entrance surface and a light exit surface, and the light entrance surface and the light exit surface are arranged oppositely on the surface of each lens; The first lens has negative optical power, the light exit surface of the first lens is a concave surface at the near optical axis, and the light incident surface of the first lens is a concave surface; The second lens has positive power, a light exiting surface of the second lens is a convex surface, and a light incident surface of the second lens is a concave surface; The third lens has positive power, the light exiting surface of the third lens is a convex surface, and the light incident surface of the third lens is a convex surface; The fourth lens has negative optical power, the light exiting surface of the fourth lens is a concave surface, and the light incident surface of the fourth lens is a concave surface; The fifth lens has positive refractive power, the light exiting surface of the fifth lens is a convex surface, and the light incident surface of the fifth lens is a concave surface; The sixth lens has positive power, the light exiting surface of the sixth lens is a convex surface, and the light incident surface of the sixth lens is a concave surface; The seventh lens has positive power, the light exiting surface of the seventh lens is a convex surface, and the light incident surface of the seventh lens is a concave surface; An air interval CTw on the optical axis between the entire lens group consisting of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens and the image source is dynamically adjustable; The exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.6 <ED / f<0.7。 2. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: <f1 / f<-3。 3. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.8 <f2 / f<2.5。 4. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.5 <f3 / f<2.5。 5. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -0.8 <f4 / f<-0.2。 6. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.5 <f5 / f<2。 7. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.6 <f6 / f<1。 8. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 0.85 <f7 / f<1.5。 9. The optical lens according to claim 1, characterized in that: The distance CTw between the incident surface of the seventh lens and the image source on the optical axis satisfies: 4 mm <CTw<10mm。 10. The optical lens according to claim 1, characterized in that: The combined focal length fa of the first lens and the second lens and the combined focal length fb of the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: <fa / fb<4.5。 11. The optical lens according to claim 1, characterized in that: A sum ΣCT of center thicknesses of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens and a total optical length TTL of the optical lens satisfy the following: 0.65<ΣCT / TTL<0.

75.

12. A near-eye display device, characterized in that: The optical signal transmission direction includes: an image source, an optical lens according to any one of claims 1 to 11; The image source is used to emit a light signal, and the light signal includes image information; The optical lens is arranged in the light emitting direction of the image source, and the seventh lens is arranged closer to the image source than the first lens. The optical lens is used to modulate the light signal emitted by the image source and transmit it to the human eye.

Images