Optical Lens and Near-Eye Display Device

Abstract

The present invention provides an optical lens and a near-eye display device, which are composed of eight lenses and sequentially include, from the human eye entrance pupil side to the image source side along the reverse direction of light transmission: a first group with positive optical power, a second group with positive optical power, and a third group with negative optical power; the first group sequentially includes, along the reverse direction of light transmission: a first lens with positive optical power and a second lens with optical power; the second group sequentially includes, along the reverse direction of light transmission: a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with positive optical power, and a sixth lens with positive optical power; the third group sequentially includes, along the reverse direction of light transmission: a seventh lens with optical power and an eighth lens with optical power. 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] In recent years, virtual reality (VR) technology has developed rapidly and has become one of the important fields of scientific and technological innovation. Currently, the VR industry is showing a booming development trend, being widely applied not only in consumer fields such as entertainment and gaming, but also demonstrating great potential in industries such as education, medical treatment, industry, and military. VR devices transmit the information of the display screen to the human eye through optical lenses and magnify the display information several times, enabling users to experience an immersive viewing experience. On the one hand, current VR head-mounted display devices are developing towards comfort and high imaging quality; on the other hand, VR head-mounted display devices can also be compatible with other devices for multi-modal experiences. To meet these requirements, an optical system needs to simultaneously achieve technical indicators such as high imaging quality, large exit pupil distance, and large field of view angle. Therefore, simultaneously meeting the above optical performances poses a great challenge to the design and aberration optimization of the optical system. Summary of the Invention

[0003] 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.

[0004] The technical solution adopted by the present invention is as follows:

[0005] An optical lens is composed of eight lenses, and successively includes from the human eye entrance pupil side to the image source side along the reverse direction of light transmission: a first group with positive optical power, a second group with positive optical power, and a third group with negative optical power;

[0006] The first group successively consists of a first lens with positive optical power and a second lens with optical power along the reverse direction of light transmission;

[0007] The second group successively consists of a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with positive optical power, and a sixth lens with positive optical power along the reverse direction of light transmission;

[0008] The third group successively consists of a seventh lens with optical power and an eighth lens with optical power along the reverse direction of light transmission;

[0009] The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens each include an incident light surface close to the image source side and an exit light surface close to the human eye entrance pupil side;

[0010] Among them, the exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.5 < ED / f < 0.95.

[0011] 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 optical lens; the image source is used for emitting an optical signal, and the optical signal includes image information; the optical lens is disposed on the light-emitting direction of the image source, and the eighth lens is disposed closer to the image source than the first lens, and the optical lens is used for modulating the optical signal emitted by the image source and transmitting it to the human eye.

[0012] Compared with the prior art, the optical lens provided by the present invention has a large exit pupil distance and a large field of view angle through specific surface shape settings and reasonable focal power distribution. The large field of view angle 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 a high resolution, and can match a monocular 4K high-definition display screen to achieve high-definition imaging quality, improve the imaging quality, and bring an excellent sensory experience to the user. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0014] Figure 1 is a schematic structural diagram of the near-eye display device provided in the embodiment of the present invention.

[0015] Figure 2 is a schematic structural diagram of the optical lens provided in Embodiment 1 of the present invention.

[0016] Figure 3 is a spot diagram of the optical lens provided in Embodiment 1 of the present invention.

[0017] Figure 4 is an MTF curve diagram of the optical lens provided in Embodiment 1 of the present invention.

[0018] Figure 5 is a schematic structural diagram of the optical lens provided in Embodiment 2 of the present invention.

[0019] Figure 6 is a spot diagram of the optical lens provided in Embodiment 2 of the present invention.

[0020] Figure 7 is an MTF curve diagram of the optical lens provided in Embodiment 2 of the present invention.

[0021] Figure 8 is a schematic structural diagram of the optical lens provided in Embodiment 3 of the present invention.

[0022] Figure 9 It is the spot diagram of the optical lens provided in Embodiment 3 of the present invention.

[0023] Figure 10 It is the MTF curve graph of the optical lens provided in Embodiment 3 of the present invention.

[0024] Figure 11 It is the structural schematic diagram of the optical lens provided in Embodiment 4 of the present invention.

[0025] Figure 12 It is the spot diagram of the optical lens provided in Embodiment 4 of the present invention.

[0026] Figure 13 It is the MTF curve graph of the optical lens provided in Embodiment 4 of the present invention.

[0027] Figure 14 It is the structural schematic diagram of the optical lens provided in Embodiment 5 of the present invention.

[0028] Figure 15 It is the spot diagram of the optical lens provided in Embodiment 5 of the present invention.

[0029] Figure 16 It is the MTF curve graph of the optical lens provided in Embodiment 5 of the present invention.

[0030] Figure 17 It is the structural schematic diagram of the optical lens provided in Embodiment 6 of the present invention.

[0031] Figure 18 It is the spot diagram of the optical lens provided in Embodiment 6 of the present invention.

[0032] Figure 19 It is the MTF curve graph of the optical lens provided in Embodiment 6 of the present invention.

[0033] Figure 20 It is the optical path schematic diagram of the near-eye display device provided in Embodiment 7 of the present invention.

[0034] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0035] To better understand the present application, more detailed descriptions of various aspects of the present application will be made with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of 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.

[0036] It should be noted that in this specification, the expressions such as first, second, third, etc. are only used to distinguish one feature from another, and do not represent any limitation on the features. 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.

[0037] In the drawings, for ease of illustration, the thickness, dimensions, 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 examples and are not drawn to an exact scale.

[0038] In this context, 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.

[0039] It should also be understood that the terms "comprises", "comprising", "has", "including", and / or "including having", 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 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 modifying a single element in the list. In addition, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". And the term "exemplary" is intended to refer to an example or illustration.

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

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

[0042] 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. 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.

[0043] Specifically, the optical lens is composed of eight lenses, which successively include: a first group with positive optical power, a second group with positive optical power, and a third group with negative optical power along the reverse direction of light transmission (i.e., from the entrance pupil side of the human eye to the image source).

[0044] Among them, the first group successively includes: a first lens with positive optical power and a second lens with optical power along the reverse direction of light transmission. The second group successively includes: a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with positive optical power, and a sixth lens with positive optical power along the reverse direction of light transmission. The third group successively includes: a seventh lens with optical power and an eighth lens with optical power 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, the seventh lens, and the eighth 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.

[0045] In some embodiments, the first lens has positive optical power, the exit light surface of the first lens is convex, and the incident light surface of the first lens can be concave or convex. The second lens has optical power, the exit light surface of the second lens is convex, and the incident light surface of the second lens can be concave or convex. The third lens has positive optical power, the exit light surface of the third lens is convex, and the incident light surface of the third lens can be concave or convex. The fourth lens has positive optical power, the exit light surface of the fourth lens is convex, and the incident light surface of the fourth lens can be concave or convex. The fifth lens has positive optical power, the exit light surface of the fifth lens is convex, and the incident light surface of the fifth lens can be concave or convex. The sixth lens has positive optical power, the exit light surface of the sixth lens is convex, and the incident light surface of the sixth lens can be concave or convex. The seventh lens has optical power, the exit light surface of the seventh lens is convex, and the incident light surface of the seventh lens can be concave or convex. The eighth lens has optical power, the exit light surface of the eighth lens can be concave or convex, and the incident light surface of the eighth lens is concave.

[0046] 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 < 0.95; the exit pupil distance ED of the optical lens satisfies: 24 mm < ED < 26 mm. 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, leaving enough space to accommodate the matching of other devices (such as an eye movement camera, self-matching myopia lenses, etc.), reducing the dizziness when worn by the human eye, and improving the sensory experience.

[0047] 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: 0.75 < IH / f < 1.2. Meeting the above conditions can enable the optical lens to match a large-size display screen to achieve high-definition imaging, bringing an excellent sensory experience to users. At the same time, it is beneficial to realize the telephoto performance of the lens, better present larger local details, make the picture more concentrated and compact, thus meeting the visual experience of the human eye.

[0048] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 2 < f1 / f < 11; the effective focal length f of the optical lens and the curvature radius R1 of the light-emitting surface of the first lens satisfy: 1 < R1 / f < 22. Meeting the above conditions, the first lens near the entrance pupil side of the human eye has a positive optical power, which can effectively converge the light, so that the outgoing light enters the human eye observation area at a relatively parallel angle of view. While ensuring a large eye movement range of the system, it provides a better immersive experience for users.

[0049] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4 < f3 / f < 17. Meeting the above conditions, the third lens can have an appropriate positive optical power, which can further converge the light, make the light enter the system at a relatively gentle angle of view, reduce the difficulty of correcting aberration and distortion, and improve the overall imaging quality.

[0050] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2 < f4 / f < 11; the effective focal length f of the optical lens and the curvature radius R7 of the light-emitting surface of the fourth lens satisfy: 1 < R7 / f < 15. Meeting the above conditions is beneficial 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 of view close to parallel, ensuring a large field of view while improving the overall imaging quality.

[0051] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 2.5 < f5 / f < 9.5; the effective focal length f of the optical lens and the radius of curvature R9 of the light-emitting surface of the fifth lens satisfy: 2 < R9 / f < 23. Meeting the above conditions is conducive to the convergence of light, enabling the light emitted from the image source side to smoothly enter the rear optical system, reducing the difficulty of correcting various aberrations, and better achieving high-quality imaging of the lens.

[0052] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1 < f6 / f < 17; the effective focal length f of the optical lens and the radius of curvature R11 of the light-emitting surface of the sixth lens satisfy: 0.6 < R11 / f < 6. 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 while improving the overall imaging quality.

[0053] In some embodiments, the clear aperture radius DM11 of the light-emitting surface of the first lens and the clear aperture radius DM82 of the light-incident surface of the eighth lens satisfy: 1 < DM11 / DM82 < 1.3. 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 angle, ensuring a large eye movement range of the system while providing a better immersive experience for users.

[0054] In some embodiments, the combined focal length fa of the first group and the effective focal length f of the optical lens satisfy: 1 < fa / f < 45. 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 while improving the overall imaging quality.

[0055] In some embodiments, the combined focal length fb of the second group and the effective focal length f of the optical lens satisfy: 0.8 < fb / f < 1.8. Meeting the above conditions is conducive to the smooth transition of light, while correcting various aberrations of the optical lens and improving the imaging quality of the optical lens.

[0056] In some embodiments, the combined focal length fc of the third group and the effective focal length f of the optical lens satisfy: -2.5 < fc / f < -0.5. Meeting the above conditions can greatly diverge the light emitted from the image source side to increase the area of the projected virtual image and provide a better immersive experience for users.

[0057] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.25 < TTL / f < 1.8; the total optical length TTL of the optical lens and the length IH of the display area of the image source that the optical lens can match satisfy: 1.4 < TTL / IH < 1.9. Meeting the above conditions can enable the lens to have a relatively compact system while having a large image plane, be able to match a large-size 4K high-definition display screen to achieve high-definition imaging, and bring an excellent sensory experience to users.

[0058] In some embodiments, the effective focal length f of the optical lens and the curvature radius R3 of the light-emitting surface of the second lens satisfy: 2 < R3 / f < 8. Meeting the above conditions can reasonably set the surface shape of the second lens, which is beneficial to the smooth transition of light and reduces the difficulty of aberration correction.

[0059] In some embodiments, the effective focal length f of the optical lens and the curvature radius R13 of the light-emitting surface of the seventh lens satisfy: 0.6 < R13 / f < 3. Meeting the above conditions can reasonably set the surface shape of the seventh lens, which is beneficial to the smooth transition of light and reduces the difficulty of aberration correction.

[0060] In some embodiments, the effective focal length f of the optical lens and the curvature radius R16 of the light-incident surface of the eighth lens satisfy: 0.3 < R16 / f < 9. Meeting the above conditions, by reasonably setting the surface shape of the eighth lens, the light emitted from a large-size image source (display screen) can be received to a large extent, and the matching degree between the lens and the large-size display screen can be improved.

[0061] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the eighth lens along the optical axis and the sum ∑AT of the distances between any two adjacent lenses of the first lens to the eighth lens on the optical axis satisfy: 2.5 < ∑CT / ∑AT < 19. Meeting the above conditions can make the structure of the lens more compact and is beneficial to the miniaturization of the lens.

[0062] In some embodiments, the optical lens satisfies the conditional formula: 48 mm < TTL < 65 mm; 28 mm < f < 45 mm; 68° < FOV < 72°, 34 mm < IH < 35 mm; where TTL represents the total 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 length of the display area 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 performance, large field of view angle, small total length, and being able to match a 4K high-definition display screen to achieve the effect of watching a giant screen image.

[0063] 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 system can be effectively corrected by the low dispersion characteristic of the glass itself. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens of the present invention can all be made of glass or plastic material.

[0064] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth 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, the seventh lens, and the eighth lens of the present invention can all adopt aspherical lenses.

[0065] 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:

[0066] ;

[0067] where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, F, G, H are the coefficients of the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order curved surfaces respectively.

[0068] 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 eighth 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.

[0069] The present invention will be further described below with multiple embodiments. In each embodiment, the thickness, curvature radius, and material selection of each lens in the optical lens are partially 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 all included in the protection scope of the present invention.

[0070] Embodiment 1

[0071] Please refer toFigure 1 , as shown is a schematic structural diagram of a near-eye display device 700 provided in an embodiment of the present invention. Please refer to Figure 2 , as shown is a schematic structural diagram of an 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 disposed on 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. It can be seen from Figure 2 that the optical lens 100 is sequentially provided with: a stop ST, a first group with a positive optical power, a second group with a positive optical power, and a third group with a negative optical power along the reverse direction of the light transmission (that is, from the entrance pupil side of the human eye to the image source surface).

[0072] The first group includes a first lens L1 and a second lens L2; the second group includes a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6; the third group includes a seventh lens L7 and an eighth lens L8.

[0073] Each 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, the seventh lens L7, and the eighth lens L8 includes an incident light surface and an exit light surface, and the incident light surface and the exit light surface are oppositely disposed on the surface of each lens. 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.

[0074] Specifically, the first lens L1 has a positive optical power. The exit light surface S1 of the first lens is a convex surface, and the incident light surface S2 of the first lens is a concave surface;

[0075] The second lens L2 has a negative optical power. The exit light surface S3 of the second lens is a convex surface, and the incident light surface S4 of the second lens is a concave surface;

[0076] The third lens L3 has a positive optical power. The exit light surface S5 of the third lens is a convex surface, and the incident light surface S6 of the third lens is a convex surface;

[0077] The fourth lens L4 has a positive optical power. The exit light surface S7 of the fourth lens is a convex surface, and the incident light surface S8 of the fourth lens is a concave surface near the optical axis;

[0078] The fifth lens L5 has a positive optical power. The exit light surface S9 of the fifth lens L5 is a convex surface, and the incident light surface S10 of the fifth lens L5 is a convex surface;

[0079] The sixth lens L6 has a positive optical power. The exit light surface S11 of the sixth lens L6 is a convex surface, and the incident light surface S12 of the sixth lens L6 is a concave surface;

[0080] 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.

[0081] The eighth lens L8 has a negative optical power. The light-emitting surface S15 of the eighth lens L8 is concave, and the light-incident surface S16 of the eighth lens L8 is concave.

[0082] 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 second lens L2 and the eighth lens L8 are made of plastic aspherical lenses, and the first lens L1, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are all made of glass aspherical lenses.

[0083] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0084] Table 1-1

[0085]

[0086] The surface type parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0087] Table 1-2

[0088]

[0089] Please refer to Figure 3 , which shows the spot diagram of the optical lens 100. The scale in the figure is 200 (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) is less than 30 μm, and this small value indicates that the imaging quality of the optical lens 100 is good.

[0090] Please refer to Figure 4 , which shows the MTF (modulation transfer function) curve graph of the optical lens 100. The abscissa in the figure 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 figure that the MTF values of the full field of view are all greater than 0.45 at 20 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 at the edge position and the center position has good consistency.

[0091] Embodiment 2

[0092] Please refer to Figure 5, which shows 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 as follows: The eighth lens L8 has a positive optical power; the light-emitting surface S15 of the eighth lens L8 is a convex surface; the first lens L1, the third lens L3, the fourth lens L4, the sixth lens L6, the seventh lens L7, and the eighth lens L8 adopt glass aspherical lenses; the second lens L2 and the fifth lens L5 both adopt plastic aspherical lenses; the optical parameters such as the curvature radius, lens thickness, and material of each lens surface are different.

[0093] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0094] Table 2-1

[0095]

[0096] The surface type parameters of the aspherical lenses of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0097] Table 2-2

[0098]

[0099] It can be seen from Figure 6 that the RMS (root mean square radius of the blur spot) is less than 30 um, and this small value indicates that the imaging quality of the optical lens 200 is good.

[0100] It can be seen from Figure 7 that the MTF values of the full field of view are all greater than 0.4 at 20 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.

[0101] Embodiment 3

[0102] Please refer to Figure 8 , 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 second lens L2 has a positive optical power; the seventh lens L7 has a positive optical power; the incident surface S2 of the first lens L1 is a convex surface; the incident surface S4 of the second lens L2 is a convex surface; the incident surface S6 of the third lens L3 is a concave surface; the incident surface S8 of the fourth lens L4 is a convex surface; the incident surface S10 of the fifth lens L5 is a concave surface; the incident surface S12 of the sixth lens L6 is a convex surface; the first lens L1, the third lens L3, the sixth lens L6, and the seventh lens L7 adopt glass aspherical lenses; the second lens L2, the fourth lens L4, the fifth lens L5, and the eighth lens L8 adopt plastic aspherical lenses; the optical parameters such as the curvature radius, lens thickness, and material of each lens surface are different.

[0103] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0104] Table 3-1

[0105]

[0106] The surface type parameters of the aspherical lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0107] Table 3-2

[0108]

[0109] It can be seen from Figure 9 that the RMS (root mean square radius of the blur spot) is less than 30 μm, and this relatively small value indicates that the imaging quality of the optical lens 300 is good.

[0110] It can be seen from Figure 10 that the MTF values of the full field of view are all greater than 0.4 at 20 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.

[0111] Embodiment 4

[0112] Please refer to Figure 11 , which shows the structural schematic diagram of the optical lens 400 provided in Embodiment 4 of the present invention. Compared with Embodiment 1, the main differences are as follows: the second lens L2 has a positive optical power; the seventh lens L7 has a positive optical power; the incident surface S2 of the first lens L1 is a convex surface; the incident surface S4 of the second lens L2 is a convex surface; the incident surface S12 of the sixth lens L6 is a convex surface; the incident surface S14 of the seventh lens L7 is a convex surface; the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 all adopt plastic aspherical lenses; the optical parameters such as the curvature radius, lens thickness, and material of each lens surface are different.

[0113] The relevant parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0114] Table 4-1

[0115]

[0116] The surface type parameters of the aspherical lens of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0117] Table 4-2

[0118]

[0119] From Figure 12 it can be seen that the RMS (root mean square radius of the dispersion spot) is less than 30 um, and this small value indicates that the imaging quality of the optical lens 400 is good.

[0120] From Figure 13 it can be seen that the MTF values of the full field of view are all greater than 0.3 at 20 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.

[0121] Embodiment 5

[0122] Please refer to Figure 14 , which shows the structural schematic diagram of the optical lens 500 provided in Embodiment 5 of the present invention. Compared with Embodiment 1, the main differences are: the second lens L2 has a positive optical power; the seventh lens L7 has a positive optical power; the incident surface S2 of the first lens L1 is a convex surface; the incident surface S4 of the second lens L2 is a convex surface; the incident surface S8 of the fourth lens L4 is a convex surface; the incident surface S10 of the fifth lens L5 is a concave surface; the incident surface S14 of the seventh lens L7 is a convex surface; the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 all adopt plastic aspherical lenses; the optical parameters such as the radius of curvature, lens thickness, and material of each lens surface are different.

[0123] The relevant parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5-1.

[0124] Table 5-1

[0125]

[0126] The surface type parameters of the aspherical lenses of the optical lens 500 in Embodiment 5 are shown in Table 5-2.

[0127] Table 5-2

[0128]

[0129] From Figure 15 it can be seen that the RMS (root mean square radius of the dispersion spot) is less than 30 um, and this small value indicates that the imaging quality of the optical lens 500 is good.

[0130] From Figure 16It can be seen that the MTF values of the full field of view are all greater than 0.58 at 20 lp / mm, and the curves are 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.

[0131] Example 6

[0132] Please refer to Figure 17 , which shows the schematic structural diagram of the optical lens 600 provided in Example 6 of the present invention. Compared with Example 1, the main differences are: the second lens L2 has a positive optical power; the seventh lens L7 has a positive optical power; the incident light surface S2 of the first lens L1 is convex; the incident light surface S4 of the second lens L2 is convex; the incident light surface S8 of the fourth lens L4 is convex; the incident light surface S10 of the fifth lens L5 is concave; the eighth lens L8 uses a plastic aspherical lens; 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 all use glass aspherical lenses; the optical parameters such as the radius of curvature, lens thickness, and material of each lens surface are different.

[0133] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6-1.

[0134] Table 6-1

[0135]

[0136] The surface type parameters of the aspherical lenses of the optical lens 600 in Example 6 are shown in Table 6-2.

[0137] Table 6-2

[0138]

[0139] From Figure 18 it can be seen that the RMS (root mean square radius of the blur spot) is less than 30 um, and this small value indicates that the imaging quality of the optical lens 600 is good.

[0140] From Figure 19 it can be seen that the MTF values of the full field of view are all greater than 0.6 at 20 lp / mm, and the curves are compact and the decline is smooth, indicating that the optical lens 600 has good resolution and contrast, and the imaging at the edge position and the center position has good consistency.

[0141] Please refer to Table 7 for the optical characteristics corresponding to the above embodiments, including the effective focal length f, the overall optical length TTL, the maximum field of view angle FOV, the entrance pupil diameter EPD, the exit pupil distance ED, the virtual image distance VID of the optical lens, and the display area length IH of the image source that the optical lens can match and the numerical values corresponding to each conditional formula in each embodiment.

[0142] Table 7

[0143]

[0144] Combining the above embodiments, the optical lens provided by the present invention has at least the following advantages:

[0145] (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 large exit pupil distance. The large field of view angle can provide a wide-field display effect, bringing a better experience to the user. The lens has a telephoto characteristic, which can better present larger local details, making the picture more concentrated and compact, thus meeting the requirements.

[0146] (2) The optical lens also has a large image plane and a high resolution, and can match a monocular 4K high-definition display screen to achieve high-definition imaging quality, improve the imaging quality, and bring an excellent sensory experience to the user.

[0147] Embodiment 7

[0148] Please refer to Figure 20 , which shows a schematic optical path diagram in a near-eye display device 700 provided by an embodiment of the present invention. The near-eye display device 700 includes an image source 10 and an optical lens (such as the optical lens 100) in any one 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.

[0149] The image source 10 is used to emit optical signals, and the optical signals include image information. Specifically, the image source 10 can be one of display screens such as Micro LED, OLED, LCD, LCOS, and M-OLED. More specifically, in this embodiment, the image source 10 can adopt a 1.35-inch Micro OLED display screen, which can provide high-definition image picture information for the optical lens.

[0150] The optical lens is arranged in the light-emitting direction of the image source 10, and the eighth 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 signal emitted by the image source 10 and transmit it to the human eye 20.

[0151] The near-eye display device 700 may be a VR glasses, VR helmet, head-mounted display device, etc. Since the above optical lens has a large exit pupil distance, a relatively large field of view angle, and a long focal length characteristic, the relatively large field of view angle 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 relatively large image plane, a relatively high resolution, and a relatively long virtual image distance. The optical signal image modulated by the optical lens is bright, clear, and has a better effect. The picture projected onto the human eye is clearer and wider. Therefore, the near-eye display device equipped with the optical lens at least has the characteristics of a wide field of view and high image quality, and can effectively improve the user's visual experience and comfort.

[0152] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0153] The above-described 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 shall be subject to the appended claims.

Claims

1. An optical lens, consisting of eight lenses, characterized in that: The optical components include: a first group with positive optical power, a second group with positive optical power, and a third group with negative optical power, from the entrance pupil side of the human eye to the image source side in the reverse direction of light transmission; The first group is composed of a first lens with positive refractive power and a second lens with positive refractive power in sequence along the reverse direction of light transmission; The second group is composed of a third lens with positive focal power, a fourth lens with positive focal power, a fifth lens with positive focal power, and a sixth lens with positive focal power in sequence along the reverse direction of light transmission; The third group is composed of a seventh lens having optical power and an eighth lens having optical power in sequence 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, the seventh lens and the eighth 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 exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.5 <ED / f<0.95。 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: 0.75 <IH / f<1.2。 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: <f1 / f<11。 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: <f3 / f<17。 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: <f4 / f<11。 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: 2.5 <f5 / f<9.5。 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: 1 <f6 / f<17。 8. The optical lens according to claim 1, characterized in that: The semi-aperture DM11 of the light exiting surface of the first lens and the semi-aperture DM82 of the light incident surface of the eighth lens satisfy: 1 <DM11 / DM82<1.3。 9. The optical lens according to claim 1, characterized in that: The combined focal length fa of the first group and the effective focal length f of the optical lens satisfy: 1 <fa / f<45。 10. The optical lens according to claim 1, characterized in that: The combined focal length fb of the second group and the effective focal length f of the optical lens satisfy: 0.8 <fb / f<1.8。 11. The optical lens according to claim 1, characterized in that: The combined focal length fc of the third group and the effective focal length f of the optical lens satisfy: -2.5 <fc / f<-0.5。 12. The optical lens according to claim 1, characterized in that: The light exit surface of the first lens is convex; the light exit surface of the second lens is convex; the light exit surface of the third lens is convex; the light exit surface of the fourth lens is convex; the light exit surface of the fifth lens is convex; the light exit surface of the sixth lens is convex; the light exit surface of the seventh lens is convex; and the light incident surface of the eighth lens is concave.

13. 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 12; 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 eighth 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