Optical Lens and Near-Eye Display Device

Abstract

The present invention provides an optical lens and a near-eye display device, which sequentially include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens along the reverse direction of light transmission; the first lens has a positive optical power; the second lens has a negative optical power, and the light-emitting surface of the second lens is concave; the third lens has a positive optical power, the light-emitting surface of the third lens is convex, and the light-incident surface of the third lens is convex; the fourth lens has an optical power, the light-emitting surface of the fourth lens is concave near the optical axis, and the light-incident surface of the fourth lens is convex near the optical axis; the fifth lens has an optical power; the sixth lens has a positive optical power, and the light-emitting surface of the sixth lens is convex; the seventh lens has a negative optical power, the light-emitting surface of the seventh lens is convex, and the light-incident surface of the seventh lens is concave. The optical lens and the near-eye display device provided by the present invention have the advantage of excellent imaging quality through specific surface shape settings and reasonable optical power distribution.

Description

Technical Field

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

[0002] With the continuous progress of optoelectronic devices and communication technologies, virtual reality (VR) technology, as a frontier direction of the new generation of information technologies, has achieved leapfrog development, and its forms and types are also increasing day by day, with continuous applications in the fields of military, medical, education, and consumption. Among them, head-mounted display devices usually transmit and magnify the information of the display screen through an optical system and finally output it to the human eye. Therefore, the human eye receives a virtual image magnified by the display screen, thereby achieving the purpose of viewing a large screen. Currently, head-mounted display devices are developing towards more miniaturization, thinner and lighter, easy to wear, and reduced load. At the same time, a large field of view, low distortion, and visual comfort have also become key evaluation indicators for the quality of head-mounted displays. A large field of view brings a better sense of immersion, and low distortion and high image quality determine the visual comfort level.

[0003] To meet these requirements, an optical system needs to simultaneously achieve indicators such as a large field of view, low distortion, and high image quality. However, an increase in the field of view often brings an increase in distortion. Therefore, simultaneously meeting the above optical performances poses a huge challenge to the design of the optical system and aberration optimization. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide an optical lens and a near-eye display device, which have the advantage of excellent imaging quality.

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

[0006] An optical lens is composed of seven lenses, and successively includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens from the side of the entrance pupil of the human eye to the side of the image source along the reverse direction of light transmission; each of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens includes an incident light surface close to the side of the image source and an emergent light surface close to the side of the entrance pupil of the human eye; the first lens has a positive optical power; the second lens has a negative optical power, and the emergent light surface of the second lens is a concave surface; the third lens has a positive optical power, the emergent light surface of the third lens is a convex surface, and the incident light surface of the third lens is a convex surface; the fourth lens has an optical power, the emergent light surface of the fourth lens is a concave surface near the optical axis, and the incident light surface of the fourth lens is a convex surface near the optical axis; the fifth lens has an optical power; the sixth lens has a positive optical power, and the emergent light surface of the sixth lens is a convex surface; the seventh lens has a negative optical power, the emergent light surface of the seventh lens is a convex surface, and the incident light surface of the seventh lens is a concave surface; wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.2 < TTL / f < 3.2; the total optical length TTL of the optical lens and the display area length IH of the image source that the optical lens can match satisfy: 1.5 < TTL / IH < 2.2.

[0007] The present invention also provides a near-eye display device, which successively includes: an image source, and the above optical lens along the direction of light signal transmission; the image source is used for emitting 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 for modulating the light signal emitted by the image source and transmitting it to the human eye.

[0008] Compared with the prior art, the optical lens provided by the present invention has a large field of view through specific surface shape settings and reasonable optical power distribution. The large field of view can provide a wide-field display effect, bringing a better experience to the user. At the same time, the optical lens also has a large image plane and high resolution, and can match a large-size 4K high-definition display screen to achieve the viewing effect of a giant screen image, improving the imaging quality and bringing an excellent sensory experience to the user. Description of the Drawings

[0009] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0010] Figure 1 It is a schematic structural diagram of the near-eye display device provided in the embodiment of the present invention.

[0011] Figure 2Schematic diagram of the optical lens provided in Embodiment 1 of the present invention.

[0012] Figure 3 Spot diagram of the optical lens provided in Embodiment 1 of the present invention.

[0013] Figure 4 MTF curve graph of the optical lens provided in Embodiment 1 of the present invention.

[0014] Figure 5 Field curvature curve graph of the optical lens provided in Embodiment 1 of the present invention.

[0015] Figure 6 Schematic diagram of the optical lens provided in Embodiment 2 of the present invention.

[0016] Figure 7 Spot diagram of the optical lens provided in Embodiment 2 of the present invention.

[0017] Figure 8 MTF curve graph of the optical lens provided in Embodiment 2 of the present invention.

[0018] Figure 9 Field curvature curve graph of the optical lens provided in Embodiment 2 of the present invention.

[0019] Figure 10 Schematic diagram of the optical lens provided in Embodiment 3 of the present invention.

[0020] Figure 11 Spot diagram of the optical lens provided in Embodiment 3 of the present invention.

[0021] Figure 12 MTF curve graph of the optical lens provided in Embodiment 3 of the present invention.

[0022] Figure 13 Field curvature curve graph of the optical lens provided in Embodiment 3 of the present invention.

[0023] Figure 14 Schematic diagram of the optical lens provided in Embodiment 4 of the present invention.

[0024] Figure 15 Spot diagram of the optical lens provided in Embodiment 4 of the present invention.

[0025] Figure 16 MTF curve graph of the optical lens provided in Embodiment 4 of the present invention.

[0026] Figure 17 Field curvature curve graph of the optical lens provided in Embodiment 4 of the present invention.

[0027] Figure 18It is a schematic structural diagram of the optical lens provided in Embodiment 5 of the present invention.

[0028] Figure 19 It is a spot diagram of the optical lens provided in Embodiment 5 of the present invention.

[0029] Figure 20 It is an MTF curve graph of the optical lens provided in Embodiment 5 of the present invention.

[0030] Figure 21 It is a field curvature curve graph of the optical lens provided in Embodiment 5 of the present invention.

[0031] Figure 22 It is a schematic optical path diagram of the near-eye display device provided in Embodiment 6 of the present invention.

[0032] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0033] To better understand the present application, various aspects of the present application will be described in more detail 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 do not limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0034] It should be noted that in this specification, the expressions such as first, second, and third are only used to distinguish one feature from another feature and do not represent any limitation on the feature. Therefore, without departing from the teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0035] In the drawings, for the sake of clarity, the thickness, size, and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are only for illustration and are not drawn to an exact scale.

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

[0037] It should also be understood that the terms "comprising", "comprises", "having", "include", and / or "including", when used in this specification, denote the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Further, when an expression such as "at least one of..." appears after a list of listed features, it modifies the entire list of listed features rather than individual elements in the list. Further, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the term "exemplary" is intended to refer to an example or illustration.

[0038] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0039] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0040] The present invention provides an optical lens. The optical lens 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 disposed 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. The image source emits light rays, and the optical lens can correct the light rays emitted by the image source to reduce or eliminate various aberrations, and a high-definition magnified virtual image can be observed on the human eye side.

[0041] Specifically, the optical lens is composed of seven lenses, and successively includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens along the reverse direction of light transmission (i.e., from the entrance pupil side of the human eye to the image source side); 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 close to the image source side and an exit light surface close to the entrance pupil side of the human eye. 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. It should be noted that the entrance pupil position of the human eye is the aperture stop of the optical lens. When the human eye is at the aperture stop position, the human eye can observe the best imaging effect.

[0042] In some embodiments, the first lens has a positive optical power. The light-emitting surface of the first lens can be concave or convex, and the light-incident surface of the first lens can be concave or convex. The second lens has a negative optical power. The light-emitting surface of the second lens is concave, and the light-incident surface of the second lens can be concave or convex. The third lens has a positive optical power. The light-emitting surface of the third lens is convex, and the light-incident surface of the third lens is convex. The fourth lens can have a positive or negative optical power. The light-emitting surface of the fourth lens is concave near the optical axis, and the light-incident surface of the fourth lens is convex near the optical axis. The fifth lens can have a positive or negative optical power. The light-emitting surface of the fifth lens can be concave or convex, and the light-incident surface of the fifth lens can be concave or convex. The sixth lens has a positive optical power. The light-emitting surface of the sixth lens is convex, and the light-incident surface of the sixth lens can be concave or convex. The seventh lens can have a negative optical power. The light-emitting surface of the seventh lens is convex, and the light-incident surface of the seventh lens is concave.

[0043] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.2 < TTL / f < 3.2; the total optical length TTL of the optical lens and the display area length IH of the image source that the optical lens can match satisfy: 1.5 < TTL / IH < 2.2. Meeting the above conditions can make the lens have a relatively compact system, and at the same time make the lens have a large image plane, be able to match a large-size image source (display screen) to achieve high-definition imaging, and bring an excellent sensory experience to the user.

[0044] In some embodiments, the display area length IH of the image source that the optical lens can match and the effective focal length f of the optical lens satisfy: 1.25 < IH / f < 1.7. Meeting the above conditions can make the optical lens match a large-size image source (display screen) to achieve high-definition imaging, bring an excellent sensory experience to the user, and at the same time be beneficial to realizing the telephoto performance of the lens, being able to better present larger local details, making the picture more concentrated and compact, so as to meet the visual experience of the human eye.

[0045] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.2 < f1 / f < 5.5. Meeting the above conditions can converge light to a large extent, make the outgoing light better converge into the human eye observation area, and while ensuring that the system provides a large eye movement range, provide a better immersive experience for the user.

[0046] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3.5 < f2 / f < -0.6. Meeting the above conditions can appropriately slow down the turning degree of light, diverge the light better into the human eye, and thus can provide a wide-field display effect and improve the user's immersion.

[0047] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 2 < f3 / f < 7; the radius of curvature R5 of the light-emitting surface of the third lens and the radius of curvature R6 of the light-incident surface of the third lens satisfy: -15 < R5 / R6 < -1. Meeting the above conditions is conducive to converging the light rays emitted from the image source side, reducing the divergence degree of the light rays, so as to enter the human eye at a nearly parallel viewing angle, ensuring a large field of view and improving the overall imaging quality at the same time.

[0048] 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 < 2.6. 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.

[0049] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -6 < f7 / f < -0.8. Meeting the above conditions can greatly diverge the light rays emitted from the image source side to increase the area of the projected virtual image, providing a better immersive experience for the user.

[0050] In some embodiments, 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: 1.1 < R13 / R14 < 10. Meeting the above conditions, by reasonably setting the meniscus shape of the seventh lens, the light rays emitted from a large-size image source (display screen) can be received to a large extent, improving the matching degree between the lens and the large-size display screen.

[0051] In some embodiments, the back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0.16 < BFL / TTL < 0.26; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.45 < BFL / f < 0.65. Meeting the above conditions can make the lens have a large optical back focus, which is conducive to reducing the interference between different components and improving the yield. At the same time, it can enable the seventh lens to better and more comprehensively receive the light rays emitted from the large-size display screen, improving the imaging quality.

[0052] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis respectively and the sum ∑AT of the distances between any two adjacent lenses of the first lens to the seventh lens on the optical axis satisfy: 9 < ∑CT / ∑AT < 35. Meeting the above conditions can make the structure of the lens more compact, which is conducive to realizing the miniaturization of the lens.

[0053] In some embodiments, the combined focal length f345 of the third lens, the fourth lens, and the fifth lens and the effective focal length f of the optical lens satisfy: 0.9 < f345 / f < 6.8. Meeting the above conditions can effectively converge light, enabling the light to enter the system at a relatively gentle viewing angle, reducing the difficulty of correcting aberration and distortion, and improving the overall imaging quality.

[0054] In some embodiments, the exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.5 < ED / f < 0.8. 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 relatively large entrance pupil distance while achieving a large field of view angle, reducing the dizziness when the human eye wears it, and improving the sensory experience.

[0055] In some embodiments, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens, and the display area length IH of the image source that the optical lens can match satisfy: 42° < (f × FOV) / IH < 58°. Meeting the above conditions can enable the lens to have a large field of view angle while having a large image plane, be able to match a large-size display screen to achieve high-definition imaging, and improve the user's immersion.

[0056] In some embodiments, 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: 0.2 < R7 / R8 < 1.8. Meeting the above conditions can better correct the edge distortion and aberration of the lens and improve the imaging quality of the lens.

[0057] 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. 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.

[0058] In some embodiments, the focal length f6 of the sixth lens and the focal length f7 of the seventh lens satisfy: -2.5 < f6 / f7 < -0.1. Meeting the above conditions can better converge the light emitted from the display screen and enable the light to enter the subsequent system at a relatively gentle viewing angle, reducing the difficulty of correcting aberration and distortion, and improving the overall imaging quality.

[0059] In some embodiments, the clear aperture semi-diameter DM11 of the light-emitting surface of the first lens and the clear aperture semi-diameter DM72 of the light-incident surface of the seventh lens satisfy: 0.58 < DM11 / DM72 < 0.82. Meeting the above conditions, by reasonably setting the aperture relationship of the first and last lenses, the light emitted from the display screen can enter the human eye observation area at a relatively parallel and wide viewing angle, ensuring a relatively large eye movement range of the system while being able to match a large-size 4K high-definition display screen to achieve high-definition imaging, and providing a better immersion experience for users.

[0060] In some embodiments, the optical lens satisfies the conditional formula: 50 mm < TTL < 72 mm; 18 mm < f < 28 mm; 63° < FOV < 75°; 33 mm < IH < 35 mm; 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 long focal length, large field of view angle, and being able to match a display screen with a relatively large size (1.33 inches) to achieve the viewing effect of a giant screen image.

[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. Additionally, when the lens material is glass, due to the low chromatic dispersion characteristic of glass itself, the geometric chromatic aberration of the optical system can be effectively corrected. The first lens, the fourth lens, the fifth lens, and the seventh lens of the present invention can be made of glass or plastic; the second lens can be made of plastic; the third lens and the sixth lens can be made of glass.

[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 system, 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 and the seventh lens of the present invention can adopt spherical or aspherical lenses, and the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens can all adopt aspherical lenses.

[0063] In various embodiments of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0064] ;

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

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

[0067] The present invention will be further described in multiple embodiments below. In each embodiment, the thickness, curvature radius, and material selection of each lens in the optical lens are somewhat different. For specific differences, please refer to the parameter tables of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any other changes, substitutions, combinations, or simplifications made without departing 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] Embodiment 1

[0069] Please refer to Figure 1 , which shows a schematic structural diagram of the near-eye display device 600 provided in the embodiment of the present invention. Please refer to Figure 2 , which shows a schematic structural diagram of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 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 emission surface of the image source 10 is the light-emitting side of the optical signal. As Figure 2 can be seen, the optical lens 100 is sequentially provided with: a stop ST, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7 along the reverse direction of the light transmission (that is, 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 each include an incident light surface close to the image source side and an exit light surface close to the entrance pupil side of the human eye. It can be understood that the surface of each lens close to the image source 10 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. The stop is the entrance pupil of the imaging of this optical system. The human eye is at the position of the stop, so that the human eye can observe the best imaging effect.

[0070] Among them, the first lens L1 has a positive optical power. The exit surface S1 of the first lens is a convex surface, and the incident surface S2 of the first lens is a convex surface;

[0071] The second lens L2 has a negative optical power. The exit surface S3 of the second lens is a concave surface, and the incident surface S4 of the second lens is a concave surface;

[0072] The third lens L3 has a positive optical power. The light-emitting surface S5 of the third lens is convex, and the light-incident surface S6 of the third lens is convex;

[0073] The fourth lens L4 has a negative optical power. The light-emitting surface S7 of the fourth lens is concave near the optical axis, and the light-incident surface S8 of the fourth lens is convex;

[0074] The fifth lens L5 has a negative optical power. The light-emitting surface S9 of the fifth lens L5 is convex, and the light-incident surface S10 of the fifth lens L5 is concave;

[0075] The sixth lens L6 has a positive optical power. The light-emitting surface S11 of the sixth lens L6 is convex, and the light-incident surface S12 of the sixth lens L6 is convex;

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

[0077] In order to better achieve a small volume of the lens and reduce costs, while enabling the lens to have a better imaging effect, both the third lens L3 and the sixth lens L6 are made of glass aspherical lenses, and the first lens L1, the second lens L2, the fourth lens L4, the fifth lens L5, and the seventh lens L7 are all made of plastic aspherical lenses.

[0078] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0079] Table 1-1

[0080]

[0081] The surface shape parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0082] Table 1-2

[0083]

[0084] Please refer to Figure 3 , which shows the spot diagram of the optical lens 100. The scale in the figure is 400 (unit: μm). The field angle (unit: degree) is shown above each figure, and the corresponding image height (unit: mm) is shown below. It can be seen from the figure that the RMS (root mean square radius of the blur spot) within the 0.9 field of view is less than 15 μm. This small value indicates that the imaging quality of the optical lens 100 is good.

[0085] Please refer to Figure 4, shown is the MTF (Modulation Transfer Function) curve graph of the optical lens 100. In the graph, the abscissa represents the spatial frequency (unit: lp / mm), and the ordinate represents the modulation degree of the optical transfer function. It can be seen from the graph that the MTF values of the full field of view are all greater than 0.55 at 16 lp / mm, and the curve is compact and the decline is smooth, indicating that the optical lens 100 has good resolution and contrast, and the imaging of the edge position and the center position has good consistency.

[0086] Please refer to Figure 5 , shown is the field curvature curve graph of the optical lens 100, which represents the bending degree of light rays in the meridional image plane and the sagittal image plane. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the field angle (unit: °). It can be seen from the graph that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±2.5 mm, indicating that the optical lens 100 can correct the field curvature well.

[0087] Embodiment 2

[0088] Please refer to Figure 6 , shown is the structural schematic diagram of the optical lens 200 provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main differences are: the fourth lens L4 has a positive optical power; the fifth lens L5 has a positive optical power; the light-emitting surface S9 of the fifth lens L5 is a concave surface; the light-incident surface S10 of the fifth lens L5 is a convex surface; the first lens L1, the third lens L3, and the sixth lens L6 adopt glass aspherical lenses; the second lens L2, the fourth lens L4, the fifth lens L5, and the seventh lens L7 all adopt plastic aspherical lenses; the optical parameters such as the curvature radius, lens thickness, and material of each lens surface are different.

[0089] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0090] Table 2-1

[0091]

[0092] The surface type parameters of the aspherical lenses of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0093] Table 2-2

[0094]

[0095] It can be seen from Figure 7 that the RMS (root mean square radius of the blur spot) within 0.9 field of view is less than 15 um, and this small value indicates that the imaging quality of the optical lens 200 is good.

[0096] It can be seen from Figure 8It can be seen that the MTF values of the full field of view are all greater than 0.68 at 16 lp / mm, and the curve is compact and the decline is smooth, indicating that the optical lens 200 has good resolution and contrast, and the imaging at the edge position and the center position has good consistency.

[0097] From Figure 9 it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within -6 mm to 2 mm, indicating that the optical lens 200 can correct the field curvature well.

[0098] Embodiment 3

[0099] Please refer to Figure 10 , which shows the structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present invention. Compared with Embodiment 1, the main differences are as follows: the fifth lens L5 has a positive optical power; the incident surface S2 of the first lens L1 is a concave surface; the exit surface S9 of the fifth lens L5 is a concave surface; the incident surface S10 of the fifth lens L5 is a convex surface; the incident surface S12 of the sixth lens L6 is a concave surface; the seventh lens L7 adopts a glass spherical lens; the second lens L2 adopts a plastic aspherical lens; the first lens L1, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 all adopt glass aspherical lenses; the optical parameters such as the radius of curvature, lens thickness, and material of each lens surface are different.

[0100] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0101] Table 3-1

[0102]

[0103] The surface type parameters of the aspherical lenses of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0104] Table 3-2

[0105]

[0106] From Figure 11 it can be seen that the RMS (root mean square radius of the blur spot) within 0.9 field of view is less than 15 um, and this small value indicates that the imaging quality of the optical lens 300 is good.

[0107] From Figure 12 it can be seen that the MTF values of the full field of view are all greater than 0.58 at 16 lp / mm, and the curve is compact and the decline is smooth, indicating that the optical lens 300 has good resolution and contrast, and the imaging at the edge position and the center position has good consistency.

[0108] From Figure 13It can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±1.5 mm, indicating that the optical lens 300 can correct the field curvature well.

[0109] Example 4

[0110] Please refer to Figure 14 , which shows the structural schematic diagram of the optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, the main differences are as follows: The fourth lens L4 has a positive optical power; the fifth lens L5 has a positive optical power; the light-emitting surface S1 of the first lens L1 is concave; the light-incident surface S4 of the second lens L2 is convex; the light-incident surface S10 of the fifth lens L5 is convex; the light-incident surface S12 of the sixth lens L6 is concave; the first lens L1 and the seventh lens L7 adopt glass spherical lenses; the second lens L2 adopts a plastic aspherical lens; the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 all adopt glass aspherical lenses; the optical parameters such as the curvature radius, lens thickness, and material of each lens surface are different.

[0111] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0112] Table 4-1

[0113]

[0114] The surface type parameters of the aspherical lenses of the optical lens 400 in Example 4 are shown in Table 4-2.

[0115] Table 4-2

[0116]

[0117] From Figure 15 it can be seen that the RMS (root mean square radius of the blur spot) within the 0.9 field of view is less than 15 μm, and this small value indicates that the imaging quality of the optical lens 400 is good.

[0118] From Figure 16 it can be seen that the MTF values of the full field of view are all greater than 0.48 at 16 lp / mm, and the curve is compact and the decline is smooth, indicating that the optical lens 400 has good resolution and contrast, and the imaging at the edge position and the center position has good consistency.

[0119] From Figure 17 it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±1 mm, indicating that the optical lens 400 can correct the field curvature well.

[0120] Example 5

[0121] Please refer to Figure 18, which shows a schematic structural diagram of the optical lens 500 provided in Embodiment 5 of the present invention. Compared with Embodiment 1, the main differences are as follows: the fourth lens L4 has a positive optical power; the fifth lens L5 has a positive optical power; the light-emitting surface S1 of the first lens L1 is concave; the light-incident surface S4 of the second lens L2 is convex; the light-incident surface S10 of the fifth lens L5 is convex; the light-incident surface S12 of the sixth lens L6 is concave; the first lens L1 and the seventh lens L7 are made of glass spherical lenses; the second lens L2 is made of plastic aspherical lens; the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all made of glass aspherical lenses; the optical parameters such as the radius of curvature of each lens surface, the lens thickness, and the material are different.

[0122] The relevant parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5-1.

[0123] Table 5-1

[0124]

[0125] The surface type parameters of the aspherical lenses of the optical lens 500 in Embodiment 5 are shown in Table 5-2.

[0126] Table 5-2

[0127]

[0128] From Figure 19 it can be seen that the RMS (root mean square radius of the blur spot) within 0.9 field of view is less than 15um, and this small value indicates that the imaging quality of the optical lens 500 is good.

[0129] From Figure 20 it can be seen that the MTF values of the full field of view are all greater than 0.48 at 16 lp / mm, and the curve is compact and the decline is smooth, indicating that the optical lens 500 has good resolution and contrast, and the imaging at the edge position and the center position has good consistency.

[0130] From Figure 21 it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±1mm, indicating that the optical lens 500 can correct the field curvature well.

[0131] Please refer to Table 6 for the optical characteristics corresponding to the above embodiments, including the effective focal length f, the total optical length TTL, the maximum field of view angle FOV, the back focal length BFL of the optical lens, and the display area length IH of the image source that the optical lens can match and the corresponding values for each conditional expression in each embodiment.

[0132] Table 6

[0133]

[0134] In summary of the above embodiments, the optical lens provided by the present invention has at least the following advantages:

[0135] (1) Through the setting of a specific surface shape and reasonable optical power distribution, the optical lens has a large field of view angle and a long focal length characteristic. The large field of view angle can provide a wide-field display effect, bringing a better experience to the user. The lens with a long focal length characteristic can better present larger local details, making the picture more concentrated and compact, thus meeting the requirements.

[0136] (2) The optical lens also has a large image plane and a high resolution, and can be matched with a large-size 4K high-definition display screen to achieve the effect of watching giant screen images, improving the imaging quality and bringing an excellent sensory experience to the user.

[0137] Embodiment 6

[0138] Please refer to Figure 22 , which shows a schematic optical path diagram in a near-eye display device 600 provided by an embodiment of the present invention. The near-eye display device 600 includes an image source 10 and an optical lens (such as the optical lens 100) in any of the foregoing embodiments of the present application. The optical lens 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 for imaging, and a high-definition magnified virtual image can be observed in the human eye 20, having an extremely realistic sensory experience.

[0139] The image source 10 is used to emit optical signals, and the optical signals include image information. Specifically, the image source 10 may be one of display screens such as Micro LED, OLED, LCD, LCOS, and M-OLED. More specifically, in this embodiment, the image source 10 may adopt a 1.33-inch Micro OLED display screen, which can provide high-definition image frame information for the optical lens.

[0140] The optical lens is disposed in the light-emitting direction of the image source 10, and the seventh lens in the optical lens is closer to the image source 10 than the first lens. The optical lens is used to modulate the optical signals emitted by the image source 10 and transmit them to the human eye 20.

[0141] The near-eye display device 600 may be a VR glasses, a VR helmet, a head-mounted display device, etc. Since the above optical lens has a large field of view and a long focal length characteristic, the large field of view can provide a wide-field display effect, improve the user's immersion, and thus bring a better experience to the user. The lens has a long focal length characteristic, which can better present larger local details, make the picture more concentrated and compact, and thus meet the requirements. At the same time, the optical lens also has a large image plane and a high resolution. The optical signal image modulated by the optical lens is bright, clear and has a better effect, and the picture projected onto 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, and can effectively improve the user's visual experience and comfort.

[0142] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection 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.

[0143] The above embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. An optical lens, consisting of seven lenses, characterized in that: 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 from the side of the entrance pupil 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 incident surface close to the image source side and a light exit surface close to the entrance pupil side of the human eye; The first lens has a positive optical power; The second lens has a negative optical power, and the light exit surface of the second lens is concave; The third lens has a positive optical power, the light exit surface of the third lens is convex, and the light incident surface of the third lens is convex; The fourth lens has an optical power, the light exit surface of the fourth lens is concave near the optical axis, and the light incident surface of the fourth lens is convex near the optical axis; The fifth lens has an optical power; The sixth lens has a positive optical power, and the light exit surface of the sixth lens is convex; The seventh lens has a negative optical power, the light exit surface of the seventh lens is convex, and the light incident surface of the seventh lens is concave; Wherein, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.2 < TTL / f < 3.2; The total optical length TTL of the optical lens and the display area length IH of the image source that the optical lens can match satisfy: 1.5 < TTL / IH < 2.

2.

2. The optical lens according to claim 1, characterized in that: The display area length IH of the image source that the optical lens can match and the effective focal length f of the optical lens satisfy: 1.25 < IH / f < 1.

7.

3. 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: 1.2 < f1 / f < 5.

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 f2 of the second lens satisfy: -3.5 < f2 / f < -0.

6.

5. 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: 2 < f3 / f < 7; the curvature radius R5 of the light exit surface of the third lens and the curvature radius R6 of the light incident surface of the third lens satisfy: -15 < R5 / R6 < -1.

6. 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 < 2.

6.

7. 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: -6 < f7 / f < -0.8; the curvature radius R13 of the light exit surface of the seventh lens and the curvature radius R14 of the light incident surface of the seventh lens satisfy: 1.1 < R13 / R14 < 10.

8. The optical lens according to claim 1, characterized in that: The back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0.16 < BFL / TTL < 0.26; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.45 < BFL / f < 0.

65.

9. The optical lens according to claim 1, characterized in that: The sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis respectively and the sum ∑AT of the distances between any two adjacent lenses of the first lens to the seventh lens on the optical axis satisfy: 9 < ∑CT / ∑AT < 35.

10. The optical lens according to claim 1, characterized in that: The combined focal length f345 of the third lens, the fourth lens and the fifth lens and the effective focal length f of the optical lens satisfy: 0.9 <f345 / f<6.8。 11. 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 10; 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.

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