Optical lenses and near-eye display devices

Abstract

This invention provides an optical lens and a near-eye display device, comprising, sequentially from the entrance pupil side of the human eye to the image source side in the opposite direction of light transmission: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; the first lens has negative optical power, its light-emitting surface is convex, and its light-receiving surface is concave; the second lens has positive optical power, its light-emitting surface is convex, and its light-receiving surface is concave; the third lens has positive optical power, its light-emitting surface is convex, and its light-receiving surface is convex; the fourth lens has positive optical power, and its light-emitting surface is convex; the fifth lens has negative optical power, and its light-receiving surface is concave; the distance CT between the light-receiving surface of the fifth lens and the image source on the optical axis is... W The range is adjustable. The optical lens provided by this invention has the advantages of adjustable diopter and excellent image quality.

Description

Technical Field

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

[0002] With the continuous advancement of optoelectronic devices and communication technologies, virtual reality (VR) technology, as a cutting-edge direction of the next generation of information technology, has experienced rapid development, with its forms and types becoming increasingly diverse and its applications expanding in military, medical, educational, and consumer fields. Head-mounted displays typically transmit and amplify information from the screen through an optical system, ultimately outputting it to the human eye. Therefore, the human eye receives a magnified virtual image of the screen, achieving the purpose of large-screen viewing. Currently, head-mounted displays are developing towards miniaturization, thinner design, ease of wear, and reduced load. Simultaneously, a wide field of view, low distortion, and visual comfort have become key evaluation indicators for head-mounted displays. A wide field of view provides a better sense of immersion, while low distortion and high image quality determine visual comfort.

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

[0004] To address the aforementioned problems, the present invention aims to provide an optical lens and a near-eye display device that have one or more advantages, such as adjustable diopter and excellent imaging quality.

[0005] The present invention provides an optical lens composed of five lenses, which are arranged sequentially from the entrance pupil side of the human eye to the image source side in the opposite direction of light transmission: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; each of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens includes an entrance surface near the image source side and an exit surface near the entrance pupil side of the human eye.

[0006] The first lens has negative optical power, its light-emitting surface is convex, and its light-incident surface is concave.

[0007] The second lens has positive optical power, its light-emitting surface is convex, and its light-incident surface is concave.

[0008] The third lens has positive optical power, and its light-emitting surface is convex, as is its light-incident surface.

[0009] The fourth lens has positive optical power and its light-emitting surface is convex.

[0010] The fifth lens has negative optical power and its incident surface is concave.

[0011] The distance CT between the incident light surface of the fifth lens and the image source on the optical axis W is adjustable;

[0012] Among them, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -3 < f12 / f < -1.4;

[0013] 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: 0.4 < f345 / f < 0.8.

[0014] Further preferably, the distance TL on the optical axis from the exit light surface of the first lens to the incident light surface of the fifth lens and the effective focal length f of the optical lens satisfy: 1 < TL / f < 1.2; the distance TL on the optical axis from the exit light surface of the first lens to the incident light surface of the fifth lens and the display area length IH of the image source that the optical lens can match satisfy:

[0015] 1.1 < TL / IH < 1.3.

[0016] Further preferably, 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: 0.92 < IH / f < 0.95; the exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.6 < ED / f < 0.62.

[0017] Further preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -1.5 < f1 / f < -0.9.

[0018] Further preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1 < f2 / f < 2.2; the radius of curvature R4 of the incident light surface of the second lens and the effective focal length f of the optical lens satisfy: 0.3 < R4 / f < 0.5.

[0019] Further preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.5 < f3 / f < 1; the radius of curvature R5 of the exit light surface of the third lens and the effective focal length f of the optical lens satisfy: 0.5 < R5 / f < 2.8.

[0020] Further preferably, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f4 / f < 11.

[0021] Further preferably, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -2.6 < f5 / f < -0.8; the radius of curvature R10 of the incident light surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < R10 / f < 1.5.

[0022] Further preferably, the central thickness CT1 of the first lens and the air gap CT12 on the optical axis between the first lens and the second lens satisfy: 7 < CT1 / CT12 < 17; the central thickness CT2 of the second lens and the air gap CT12 on the optical axis between the first lens and the second lens satisfy: 8.5 < CT2 / CT12 < 13.

[0023] Further preferably, the sum ∑CT of the central thicknesses along the optical axis of the first lens to the fifth lens respectively and the sum ∑AT of the distances on the optical axis between any two adjacent lenses among the first lens to the fifth lens satisfy: 4 < ∑CT / ∑AT < 7.

[0024] 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 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 fifth lens is arranged 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.

[0025] Compared with the prior art, the optical lens provided by the present invention has a telephoto characteristic through specific surface shape settings and reasonable optical power distribution, can better present larger local details, and improve the picture quality; moreover, the optical lens provided by the present invention can achieve diopter adjustment from -7D to +2D by adjusting the spatial interval distance between the entire lens group and the image source on the optical axis, and has small distortion and high imaging quality at different diopters, bringing an excellent sensory experience to users. Description of the Drawings

[0026] 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, where:

[0027] Figure 1 It is a schematic structural diagram of the near-eye display device provided in the embodiment of the present invention.

[0028] Figure 2 It is a schematic structural diagram of the optical lens provided in Embodiment 1 of the present invention.

[0029] Figure 3 It is a field curvature curve diagram of the optical lens provided in Embodiment 1 of the present invention.

[0030] Figure 4 This is the F-Tan(θ) distortion curve of the optical lens provided in Embodiment 1 of the present invention.

[0031] Figure 5 This is the MTF curve of the optical lens provided in Embodiment 1 of the present invention.

[0032] Figure 6 This is a schematic diagram of the structure of the optical lens provided in Embodiment 2 of the present invention.

[0033] Figure 7 This is a field curvature curve diagram of the optical lens provided in Embodiment 2 of the present invention.

[0034] Figure 8 This is the F-Tan(θ) distortion curve of the optical lens provided in Embodiment 2 of the present invention.

[0035] Figure 9 This is the MTF curve of the optical lens provided in Embodiment 2 of the present invention.

[0036] Figure 10 This is a schematic diagram of the structure of the optical lens provided in Embodiment 3 of the present invention.

[0037] Figure 11 This is a field curvature curve diagram of the optical lens provided in Embodiment 3 of the present invention.

[0038] Figure 12 This is the F-Tan(θ) distortion curve of the optical lens provided in Embodiment 3 of the present invention.

[0039] Figure 13 This is the MTF curve of the optical lens provided in Embodiment 3 of the present invention.

[0040] Figure 14 This is a schematic diagram of the structure of the optical lens provided in Embodiment 4 of the present invention.

[0041] Figure 15 This is a field curvature curve diagram of the optical lens provided in Embodiment 4 of the present invention.

[0042] Figure 16 This is the F-Tan(θ) distortion curve of the optical lens provided in Embodiment 4 of the present invention.

[0043] Figure 17 This is the MTF curve of the optical lens provided in Embodiment 4 of the present invention.

[0044] Figure 18 This is a schematic diagram of the optical path of the near-eye display device provided in Embodiment 5 of the present invention.

[0045] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0046] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this 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.

[0047] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0048] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0049] In this paper, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity 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 location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region.

[0050] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0051] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0053] This invention provides an optical lens for modulating and transmitting light signals emitted from an image source to the entrance pupil of the human eye. The optical lens is positioned in the light-emitting direction of the image source, meaning the emitting surface of the image source is the light-emitting side. The optical lens consists of five lenses, arranged sequentially from the entrance pupil to the image source in the opposite direction of light transmission: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. Each of the first, second, third, fourth, and fifth lenses includes an incident light surface near the image source and an exit light surface near the entrance pupil. It is understood that the surface of each lens near the image source is called the incident light surface, and the surface of each lens near the entrance pupil is called the exit light surface. It should be noted that the entrance pupil of the human eye is the aperture stop of the optical lens.

[0054] In some embodiments, the first lens may have negative optical power, with a convex light-emitting surface and a concave light-receiving surface. The second lens may have positive optical power, with a convex light-emitting surface and a concave light-receiving surface. The third lens may have positive optical power, with both its light-emitting and light-receiving surfaces being convex. The fourth lens may have positive optical power, with a convex light-emitting surface and either a convex or concave light-receiving surface. The fifth lens may have negative optical power, with either a convex or concave light-emitting surface and a concave light-receiving surface.

[0055] To meet the wearing needs of users with different refractive degrees, the air gap between the entire lens group (composed of the first lens, second lens, third lens, fourth lens, and fifth lens) and the image source on the optical axis can be dynamically adjusted. W (That is, the distance on the optical axis between the incident surface of the fifth lens and the image source) is used to adjust the optical lens between different refractive powers, thus effectively meeting the wearing needs of users with different refractive degrees. More specifically, the distance on the optical axis between the incident surface of the fifth lens and the image source side is CT. W The adjustment range meets the requirement of: 3.5mm <CT W<9.1 mm. Meeting the above range can endow the lens with a relatively large optical back focus. On the one hand, it can provide a relatively large refraction space for the light rays emitted from the image source side, improving the adaptability of the optical lens to a large-size display screen. At the same time, a relatively large space is reserved between the image source and the optical lens, facilitating the adjustment of the distance between the two, so that a diopter adjustment within a relatively large range (such as -7D to +2D) can be achieved, meeting the wearing needs of users with different myopia or hyperopia degrees. Moreover, the diopter adjustment method of this application is simple and can be achieved only by moving the screen.

[0056] In some embodiments, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -3 < f12 / f < -1.4; 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: 0.4 < f345 / f < 0.8. Meeting the above range can enable the light rays at the large marginal field angle to enter the human eye observation area at a more appropriate angle of view. While achieving a large field angle of the lens, it also meets the characteristics of low distortion and high image quality. At the same time, it is also beneficial for the light rays emitted from the image source side to smoothly transition to the human eye observation area, correcting various aberrations of the optical lens and improving the imaging quality of the optical lens.

[0057] In some embodiments, the distance TL on the optical axis from the light-emitting surface of the first lens to the light-incident surface of the fifth lens and the effective focal length f of the optical lens satisfy: 1 < TL / f < 1.2; the distance TL on the optical axis from the light-emitting surface of the first lens to the light-incident surface of the fifth lens and the display area length IH of the image source that the optical lens can match satisfy: 1.1 < TL / IH < 1.3. Meeting the above range can endow the lens with a relatively long focal length, enabling better presentation of larger local details and improving the picture quality. At the same time, it also endows the lens with a relatively large image plane, capable of matching a relatively large-size image source (display screen) to achieve high-definition imaging, bringing an excellent sensory experience to users.

[0058] 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: 0.92 < IH / f < 0.95; meeting the above range can enable the optical lens to match a relatively large-size image source (display screen) to achieve high-definition imaging, bringing an excellent sensory experience to users. At the same time, it is also beneficial for achieving the long focal length performance of the lens, enabling better presentation of larger local details, making the picture more concentrated and compact, thus meeting the visual experience of the human eye. Further, the exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.6 < ED / f < 0.62, where 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. By reasonably controlling the ratio of the exit pupil distance to the focal length, the lens can have a relatively large entrance pupil distance, reducing the dizziness feeling when the human eye wears it and improving the sensory experience.

[0059] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -1.5 < f1 / f < -0.9. Meeting the above range allows the outgoing light to enter the human eye observation area at a relatively parallel viewing angle, providing a better immersive experience for the user.

[0060] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1 < f2 / f < 2.2; the radius of curvature R4 of the incident light surface of the second lens and the effective focal length f of the optical lens satisfy: 0.3 < R4 / f < 0.5. Meeting the above range can effectively converge the light, allowing the outgoing light to enter the human eye observation area at a relatively parallel viewing angle, providing a better immersive experience for the user.

[0061] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.5 < f3 / f < 1; the radius of curvature R5 of the outgoing light surface of the third lens and the effective focal length f of the optical lens satisfy: 0.5 < R5 / f < 2.8. Meeting the above range is beneficial for further converging the light, enabling the light 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.

[0062] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f4 / f < 11. Meeting the above range is beneficial for converging the light emitted from the image source side, reducing the divergence degree of the light, so as to enter the human eye at a nearly parallel viewing angle, ensuring a large viewing angle while improving the overall imaging quality.

[0063] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -2.6 < f5 / f < -0.8; the radius of curvature R10 of the incident light surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < R10 / f < 1.5. Meeting the above range can diverge the light emitted from the image source side to a greater extent, so as to increase the area of the projected virtual image, providing a better immersive experience for the user.

[0064] In some embodiments, the central thickness CT1 of the first lens and the air gap CT12 between the first lens and the second lens on the optical axis satisfy: 7 < CT1 / CT12 < 17; the central thickness CT2 of the second lens and the air gap CT12 between the first lens and the second lens on the optical axis satisfy: 8.5 < CT2 / CT12 < 13. Meeting the above range can effectively slow down the turning degree of the light by reasonably controlling the ratio of the central thickness and the air interval of the first and second lenses, better correct the field curvature of the peripheral image, obtain better imaging quality, and at the same time enable the lens to meet the small size requirement.

[0065] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis respectively and the sum ∑AT of the distances between any two adjacent lenses of the first lens to the fifth lens on the optical axis satisfy: 4 < ∑CT / ∑AT < 7. Meeting the above range can make the structure of the lens more compact and is conducive to realizing the miniaturization of the lens.

[0066] In some embodiments, the curvature radius R1 of the light-emitting surface of the first lens and the curvature radius R2 of the light-incident surface of the first lens satisfy: 1.5 < R1 / R2 < 2.2. Meeting the above range can effectively converge light rays, enabling the outgoing light to enter the human eye observation area at a relatively parallel viewing angle and providing a better immersive experience for users.

[0067] In some embodiments, the curvature radius R3 of the light-emitting surface of the second lens and the curvature radius R4 of the light-incident surface of the second lens satisfy: 0.6 < R3 / R4 < 1. Meeting the above range is conducive to converging light rays, enabling the outgoing light to enter the human eye observation area at a relatively parallel viewing angle and providing a better immersive experience for users.

[0068] In some embodiments, the curvature radius R5 of the light-emitting surface of the third lens and the curvature radius R6 of the light-incident surface of the third lens satisfy: -5 < R5 / R6 < -1. Meeting the above range is conducive to further converging 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 realizing the high-quality imaging of the lens.

[0069] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -1 < f1 / f2 < -0.05. Meeting the above range can enable the light rays at the large edge field angle to enter the human eye observation area at a relatively appropriate viewing angle, while realizing the large field angle of the lens and meeting the characteristics of low distortion and high image quality.

[0070] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: 0 < f3 / f4 < 0.8. Meeting the above range is conducive to converging the light rays emitted from the image source side, enabling the light rays to enter the human eye observation area at a relatively gentle viewing angle and providing a better immersive experience for users.

[0071] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis respectively and the distance TL on the optical axis from the light-emitting surface of the first lens to the light-incident surface of the fifth lens satisfy: 0.78 < ∑CT / TL < 0.88. Meeting the above range can make the structure of the lens more compact, and at the same time facilitate the movement of the image source (display degree) for diopter adjustment, so as to meet the wearing needs of users with different diopters.

[0072] In some embodiments, the combined focal length f12 of the first lens and the second lens and the combined focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy: -5.2 < f12 / f345 < -3. Meeting the above range, by reasonably setting the focal length relationship between the front and rear lens groups, the light enters the human eye at a relatively gentle angle, reducing the difficulty of correcting aberration and distortion, improving the imaging quality, and providing a better sensory experience for users wearing it.

[0073] In some embodiments, the effective aperture DM11 of the light-emitting surface of the first lens and the effective aperture DM52 of the light-incident surface of the fifth lens satisfy: 1 < DM11 / DM52 < 1.1. Meeting the above range, by setting the apertures of the first and last lenses to be relatively close, the light emitted by the display screen can enter the human eye observation area at a relatively parallel viewing angle, while ensuring a large eye movement range provided by the system, improving the comfort of the user experience.

[0074] In some embodiments, the optical lens satisfies the conditional formula: 19.5mm < f < 20mm; 51.5° < FOV < 52.5°; 18.3mm < IH < 18.6mm; where 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 range indicates that the optical lens provided by the embodiments of the present invention has the advantages of small distortion, long focal length characteristics, large exit pupil distance, large adjustable diopter range, and being able to match a 4K high-resolution screen to achieve high-definition imaging.

[0075] 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. When the lens material is glass, the geometric chromatic aberration of the optical lens can be effectively corrected by the low dispersion characteristic of the glass itself. More specifically, the first lens, the third lens, and the fifth lens of the present invention can all adopt glass lenses, and the second lens and the fourth lens can both adopt glass lenses or plastic lenses.

[0076] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the fifth 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, and the fourth lens of the present invention all adopt aspherical lenses, and the fifth lens adopts a spherical lens.

[0077] 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:

[0078]

[0079] Where z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, and B, C, D, E, F, G, and H are the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order surface coefficients, respectively.

[0080] In addition, the present invention also provides a near-eye display device, which includes, in sequence along the light signal transmission direction: an image source and the aforementioned optical lens; the image source is used to emit light signals, the light signals including image information; the optical lens is disposed in the light emission direction of the image source, and the fifth lens is disposed closer to the image source than the first lens, the optical lens being used to modulate the light signal emitted by the image source and transmit it to the human eye.

[0081] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

[0082] Example 1

[0083] Please see Figure 1 The diagram shown is a structural schematic of the near-eye display device 500 provided in an embodiment of the present invention. Please refer to [link / reference]. Figure 2 The diagram shows a schematic of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 is used to modulate the light 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 in the light-emitting direction of the image source 10, that is, the emitting surface of the image source 10 is the light-emitting side of the light signal. Figure 2 As can be seen, the optical lens 100, arranged sequentially along the opposite direction of light transmission (i.e., from the entrance pupil side of the human eye to the image source side), includes: an aperture stop ST, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5. Each of the first lens L1, second lens L2, third lens L3, fourth lens L4, and fifth lens L5 includes an incident light surface near the image source side and an exit light surface near the entrance pupil side of the human eye. It can be understood that the surface of each lens near the image source 10 is called the incident light surface of that lens, and the surface of each lens near the entrance pupil side of the human eye is called the exit light surface of that lens. It should be noted that the entrance pupil position of the human eye is the aperture stop ST of the optical lens 100.

[0084] Among them, the first lens L1 has negative optical power, the light-exiting surface S1 of the first lens is convex, and the light-incident surface S2 of the first lens is concave.

[0085] The second lens L2 has positive optical power, the light-exiting surface S3 of the second lens is convex, and the light-incident surface S4 of the second lens is concave.

[0086] The third lens L3 has positive optical power, the light-exiting surface S5 of the third lens is convex, and the light-incident surface S6 of the third lens is convex.

[0087] The fourth lens L4 has positive optical power, the light-exiting surface S7 of the fourth lens is convex, and the light-incident surface S8 of the fourth lens is convex.

[0088] The fifth lens L5 has negative optical power. The light-exiting surface S9 of the fifth lens is concave, and the light-incident surface S10 of the fifth lens is concave.

[0089] The first lens L1, the third lens L3, and the fourth lens L4 are all glass aspherical lenses, the second lens L2 is a plastic aspherical lens, and the fifth lens L5 is a glass spherical lens.

[0090] To meet the wearing needs of users with different refractive degrees, the air gap between the entire lens group (composed of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5) and the image source 10 on the optical axis can be dynamically adjusted. W (The distance between the light-incident surface of the fifth lens L5 and the image source 10 on the optical axis) is used to adjust the optical lens between different diopter values, thereby well meeting the wearing needs of users with different diopter degrees.

[0091] Specifically, in this embodiment, the distance CT between the light-incident surface of the fifth lens and the image source side on the optical axis is... W The adjustment range is 4.278~7.646mm, allowing for diopter adjustment from -700 to 200 degrees (-7D to 2D), thus providing a good sensory experience for users with different degrees of myopia or hyperopia. Figure 2 The diagram shown is a structural schematic of the optical lens 100 when the refractive power is 0D (0°). At this time, the CT... W It is 6.837mm; when CT W At a focal length of 4.278mm, the refractive power of optical lens 100 is -7D (-700°); when CT... W At a focal length of 7.646mm, the diopter of the optical lens 100 is 2D (200°). In this embodiment, the diopter can be adjusted by moving the image source (display screen).

[0092] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0093] Table 1-1

[0094]

[0095] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0096] Table 1-2

[0097]

[0098]

[0099] Please refer to Figure 3 The figure shows the field curvature curve of the optical lens 100, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.6 mm to 0.4 mm, indicating that the optical lens 100 can correct the field curvature well.

[0100] Please refer to Figure 4 The figure shows the F-Tan(θ) distortion curve of optical lens 100. The horizontal axis represents the percentage of F-Tan(θ) distortion, and the vertical axis represents the half field of view (unit: degrees). Figure 4 It can be seen that the F-Tan(θ) distortion value of the image received by the user's eye at the high position is controlled within -6% to 0%, indicating that the distortion of the optical lens 100 has been well corrected.

[0101] Please refer to Figure 5 The figure shows the MTF (modulation transfer function) curve of the optical lens 100, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of this embodiment is above 0.6 throughout the entire field of view. The MTF curve decreases smoothly and evenly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution in both low and high frequency conditions.

[0102] from Figure 3 , Figure 4 , Figure 5 It can be seen that the aberrations of the optical lens 100 are well balanced, resulting in good image quality.

[0103] Example 2

[0104] Please see Figure 6The figure shows a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the light-incident surface S8 of the fourth lens L4 is concave; the light-exit surface S9 of the fifth lens L5 is convex; the second lens L2 is a glass aspherical lens; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0105] In this embodiment, the distance CT between the incident surface of the fifth lens and the image source side on the optical axis is... W The adjustment range is 4.311–7.646 mm. For example... Figure 6 The diagram shown is a structural schematic of the optical lens 200 when the refractive power is 0D (0°). At this time, the CT... W It is 6.841mm; when CT W At a focal length of 4.311mm, the refractive power of the optical lens 200 is -7D (-700°); when CT... W At a focal length of 7.646mm, the diopter of the optical lens 200 is 2D (200°).

[0106] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0107] Table 2-1

[0108]

[0109]

[0110] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0111] Table 2-2

[0112]

[0113] Please refer to Figure 7 The figure shows the field curvature curve of the optical lens 200, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.2 mm, indicating that the optical lens 200 can correct the field curvature well.

[0114] Please refer to Figure 8 The figure shows the F-Tan(θ) distortion curve of optical lens 200. The horizontal axis represents the percentage of F-Tan(θ) distortion, and the vertical axis represents the half field of view (unit: degrees). Figure 8It can be seen that the F-Tan(θ) distortion value of the image received by the user's eye at the high position is controlled within -4% to 0%, indicating that the distortion of the optical lens 200 has been well corrected.

[0115] Please refer to Figure 9 The figure shows the MTF (modulation transfer function) curve of the optical lens 200, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of this embodiment is above 0.8 throughout the entire field of view. The MTF curve decreases smoothly and evenly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution in both low and high frequency conditions.

[0116] from Figure 7 , Figure 8 , Figure 9 It can be seen that the aberrations of the 200 optical lens are well balanced, resulting in good image quality.

[0117] Example 3

[0118] Please see Figure 10 The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the light-incident surface S8 of the fourth lens L4 is concave; the second lens L2 is a glass aspherical lens; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0119] In this embodiment, the distance CT between the incident surface of the fifth lens and the image source side on the optical axis is... W The adjustment range is 3.755~7.102mm. For example... Figure 10 The diagram shown is a structural schematic of the optical lens 300 when the diopter is 0D (0°). At this time, the CT... W It is 6.292mm; when CT W At 3.755mm, the refractive power of the optical lens 300 is -7D (-700°); when CT... W At a focal length of 7.102mm, the diopter of the optical lens 300 is 2D (200°).

[0120] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0121] Table 3-1

[0122]

[0123] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0124] Table 3-2

[0125]

[0126]

[0127] Please refer to Figure 11 The figure shows the field curvature curve of optical lens 300, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.2 mm, indicating that optical lens 300 can correct field curvature well.

[0128] Please refer to Figure 12 The figure shows the F-Tan(θ) distortion curve of optical lens 300. The horizontal axis represents the percentage of F-Tan(θ) distortion, and the vertical axis represents the half field of view (unit: degrees). From Figure 12 It can be seen that the F-Tan(θ) distortion value of the image received by the user's eye at the high position is controlled within -6% to 0%, indicating that the distortion of the optical lens 300 has been well corrected.

[0129] Please refer to Figure 13 The figure shows the MTF (modulation transfer function) curve of the optical lens 300, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of this embodiment is above 0.7 throughout the entire field of view. The MTF curve decreases smoothly and evenly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution in both low and high frequency conditions.

[0130] from Figure 11 , Figure 12 , Figure 13 It can be seen that the aberrations of the 300mm optical lens are well balanced, resulting in good image quality.

[0131] Example 4

[0132] Please see Figure 14 The diagram shows a schematic of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the light-incident surface S8 of the fourth lens L4 is concave; the light-exit surface S9 of the fifth lens L5 is convex; the second lens L2 is a glass aspherical lens; the fourth lens L4 is a plastic aspherical lens; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0133] In this embodiment, the distance CT between the incident surface of the fifth lens and the image source side on the optical axis is... WThe adjustment range is 5.545–8.929 mm. For example... Figure 14 The diagram shown is a structural schematic of the optical lens 400 when the refractive power is 0D (0°). At this time, the CT... W It is 8.117mm; when CT W At 5.545mm, the refractive power of the 400mm optical lens is -7D (-700°); when CT... W At a focal length of 8.929mm, the optical lens 400 has a diopter of 2D (200°).

[0134] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0135] Table 4-1

[0136]

[0137]

[0138] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0139] Table 4-2

[0140]

[0141] Please refer to Figure 15 The figure shows the field curvature curve of optical lens 400, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within ±0.4 mm, indicating that optical lens 400 can correct field curvature well.

[0142] Please refer to Figure 16 The figure shows the F-Tan(θ) distortion curve of optical lens 400. The horizontal axis represents the percentage of F-Tan(θ) distortion, and the vertical axis represents the half field of view (unit: degrees). Figure 16 It can be seen that the F-Tan(θ) distortion value of the image received by the user's eye at the high position is controlled within -6% to 0%, indicating that the distortion of the optical lens 400 has been well corrected.

[0143] Please refer to Figure 17The figure shows the MTF (modulation transfer function) curve of the optical lens 400, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of this embodiment is above 0.6 throughout the entire field of view. The MTF curve decreases smoothly and evenly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution in both low and high frequency conditions.

[0144] from Figure 15 , Figure 16 , Figure 17 It can be seen that the aberrations of the 400mm optical lens are well balanced, resulting in good image quality.

[0145] Please refer to Table 5, which shows the optical characteristics of the optical lenses provided in the above four embodiments when the diopter is 0D (0°), including the effective focal length f, total optical length TTL, distance TL on the optical axis from the light-emitting surface of the first lens to the light-incident surface of the fifth lens, maximum field of view FOV, entrance pupil diameter EPD, and the display area length IH of the image source that the optical lens can match, as well as the values ​​corresponding to each conditional expression in each embodiment.

[0146] Table 5

[0147] Parameters and conditional expressions Example 1 Example 2 Example 3 Example 4 f(mm) 19.700 19.642 19.680 19.720 FOV (°) 52.000 52.000 52.000 52.000 EPD (mm) 4.000 4.000 4.000 4.000 TTL(mm) 30.759 29.606 29.321 29.540 IH(mm) 18.402 18.406 18.406 18.404 TL(mm) 23.223 22.065 22.329 20.723 TL / f 1.179 1.123 1.135 1.051 TL / IH 1.262 1.199 1.213 1.126 IH / f 0.934 0.937 0.935 0.933 ED / f 0.609 0.611 0.610 0.609 f1 / f -0.955 -1.352 -1.296 -1.100 f2 / f 1.101 2.087 1.537 1.935 f3 / f 0.828 0.920 0.665 0.572 f4 / f 1.175 1.452 2.955 10.142 f5 / f -0.923 -1.751 -1.293 -2.481 R1 / R2 1.759 1.740 1.778 2.001 R3 / R4 0.703 0.897 0.822 0.899 R5 / R6 -4.380 -2.372 -2.071 -1.183 R4 / f 0.400 0.353 0.451 0.412 R5 / f 2.682 1.816 1.141 0.715 R10 / f 1.025 0.989 1.379 0.849 f1 / f2 -0.868 -0.648 -0.843 -0.568 f3 / f4 0.705 0.633 0.225 0.056 ∑CT / ∑AT 6.530 5.112 4.122 5.654 ∑CT / TL 0.867 0.836 0.805 0.850 CT1 / CT12 12.227 15.830 8.772 8.053 CT2 / CT12 11.712 12.062 11.492 9.252 f12 / f -2.877 -2.354 -2.776 -1.559 f345 / f 0.623 0.562 0.556 0.482 f12 / f345 -4.614 -4.189 -4.991 -3.237 DM11 / DM52 1.019 1.030 1.041 1.020

[0148] In summary, the optical lens provided by the present invention has at least the following advantages:

[0149] (1) By setting specific surface shapes and reasonable optical power distribution, the optical lens has telephoto characteristics, which can better present larger local details and improve image quality. At the same time, the optical lens has low distortion characteristics, which improves image quality and brings a better user experience.

[0150] (2) The optical lens can be adjusted by moving the screen (-7D to +2D), and the lens has high imaging quality under different diopter, which can meet the needs of different myopic or hyperopic users and provide users with a better experience.

[0151] (3) The optical lens uses five lenses, and the overall length of the design is small, the number of lenses is small, and the surface shape is simple, which meets the development trend of miniaturization and lightweighting.

[0152] Example 5

[0153] Please see Figure 18The diagram shows a schematic of the optical path in a near-eye display device 500 according to an embodiment of the present invention. The near-eye display device 500 includes an image source 10 and an optical lens (such as optical lens 100) as described in any of the preceding embodiments of this application. The optical lens 100 is located between the human eye 20 and the image source 10. Image information emitted from the image source 10 enters the human eye 20 through the optical lens 100 to form an image, in which a high-definition magnified virtual image can be observed, providing an extremely realistic sensory experience.

[0154] The image source 10 is used to emit light signals, which include image information. Specifically, the image source 10 can be one of the following displays: Micro LED, OLED, LCD, LCOS, M-OLED, etc., which can provide high-definition image information to the optical lens 100.

[0155] The optical lens 100 is disposed in the light-emitting direction of the image source 10, and the fifth lens in the optical lens 100 is disposed closer to the image source 10 than the first lens. The optical lens 100 is used to modulate and transmit the light signal emitted by the image source 10 to the human eye 20.

[0156] The near-eye display device 500 can be VR glasses, VR helmets, head-mounted displays, etc. By adjusting the distance between the lens and the image source, the refractive power is adjustable (-7D to 2D), allowing users with different degrees of myopia or hyperopia to have a good wearing experience. Because the aforementioned optical lens has telephoto characteristics and low distortion, it improves image quality and provides a better user experience. Simultaneously, the optical lens also has a large image plane and high resolution, resulting in a brighter, clearer, and better image after modulation by the optical lens. The image projected to the human eye is clearer. Therefore, the near-eye display device equipped with the aforementioned optical lens has at least the characteristics of low distortion and high image quality, effectively improving the user's visual experience and comfort.

[0157] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0158] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens, comprising five lenses, characterized in that, Along the reverse direction of light transmission, from the side of the entrance pupil of the human eye to the side of the image source, it successively includes: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; each of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens includes an incident light surface close to the side of the image source and an exit light surface close to the side of the entrance pupil of the human eye; The first lens has a negative optical power, its exit light surface is convex, and its incident light surface is concave; The second lens has a positive optical power, its exit light surface is convex, and its incident light surface is concave; The third lens has a positive optical power, its exit light surface is convex, and its incident light surface is convex; The fourth lens has a positive optical power, and its exit light surface is convex; The fifth lens has a negative optical power, and its incident light surface is concave; The distance CT between the incident surface of the fifth lens and the image source on the optical axis W The range is adjustable; Wherein, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: -3 < f12 / f < -1.4; 2. 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: 0.4 < f345 / f < 0.

8.

3. The optical lens according to claim 1, characterized in that, The distance TL on the optical axis from the exit light surface of the first lens to the incident light surface of the fifth lens and the effective focal length f of the optical lens satisfy: 1 < TL / f < 1.2; the distance TL on the optical axis from the exit light surface of the first lens to the incident light surface of the fifth lens and the display area length IH of the image source that the optical lens can match satisfy: 1.1 < TL / IH < 1.

3.

4. 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: 0.92 < IH / f < 0.95; the exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.6 < ED / f < 0.

62.

5. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -1.5 < f1 / f < -0.

9.

6. The optical lens according to claim 1, characterized in that, The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1 < f2 / f < 2.2; the radius of curvature R4 of the incident light surface of the second lens and the effective focal length f of the optical lens satisfy: 0.3 < R4 / f < 0.

5.

7. The optical lens according to claim 1, characterized in that, The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.5 < f3 / f < 1; the radius of curvature R5 of the exit light surface of the third lens and the effective focal length f of the optical lens satisfy: 0.5 < R5 / f < 2.

8.

8. The optical lens according to claim 1, characterized in that, The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1 < f4 / f < 11. The focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -2.6 < f5 / f < -0.8; the radius of curvature R10 of the incident light surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < R10 / f < 1.

5.

9. The optical lens according to claim 1, characterized in that, The central thickness CT1 of the first lens and the air gap CT12 between the first lens and the second lens on the optical axis satisfy: 7 < CT1 / CT12 < 17; the central thickness CT2 of the second lens and the air gap CT12 between the first lens and the second lens on the optical axis satisfy: 8.5 < CT2 / CT12 < 13.

10. The optical lens according to claim 1, characterized in that, The sum ∑CT of the central thicknesses along the optical axis of the first lens to the fifth lens respectively and the sum ∑AT of the distances between any two adjacent lenses of the first lens to the fifth lens on the optical axis satisfy: 4 < ∑CT / ∑AT < 7.

11. A near-eye display device, characterized in that, In the light signal transmission direction, it successively includes: an image source, an optical lens as described in any one of claims 1-10; 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 fifth 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