Optical lens and near-eye display device

Abstract

The application provides an optical lens and a near-eye display device, which comprises, in sequence from the human eye entrance pupil side to the image source side along the reverse direction of light transmission, a first lens, a second lens, a third lens, a fourth lens and a fifth lens; the first lens has positive refractive power, and its light exit surface is a convex surface; the second lens has negative refractive power, and its light exit surface is a concave surface and its light entrance surface is a concave surface; the third lens has positive refractive power, and its light entrance surface is a convex surface; the fourth lens has negative refractive power; the fifth lens has negative refractive power, and its light entrance surface is a concave surface; the distance CT between the light entrance surface of the fifth lens and the image source on the optical axis can be adjusted. W The optical lens provided by the application has the advantages of adjustable refractive power and excellent imaging quality.

Description

TECHNICAL FIELD

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

[0002] With the continuous progress of optoelectronic devices and communication technology, virtual reality (VR) technology as a leading direction of new generation information technology has developed rapidly, and its forms and types are increasingly diverse, and its applications in military, medical, education and consumer fields are constantly increasing. The head-mounted display device usually transmits and magnifies the information of the display screen through the optical system, and finally outputs it to the human eye, so that the human eye receives the virtual image of the magnified display screen, thereby achieving the purpose of large-screen viewing. The current head-mounted display device is developing towards smaller size, thinner, easier to wear, and lighter load. At the same time, large field of view, low distortion and visual comfort have become key evaluation indicators of head-mounted display. A large field of view brings better immersion, low distortion and high image quality determine the visual comfort.

[0003] In order to meet these requirements, the optical system needs to simultaneously achieve large field of view, low distortion, high image quality and other indicators, but the increase of the field of view will often bring the increase of distortion, so simultaneous satisfaction of the above optical performance brings great challenges to the design and aberration optimization of the optical system. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide an optical lens and a near-eye display device, which has one or more of the advantages of adjustable diopter and excellent imaging quality.

[0005] The present application provides an optical lens composed of five lenses, which includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens in order from the human eye entrance pupil side to the image source side along the reverse direction of light transmission; the first lens, the second lens, the third lens, the fourth lens and the fifth lens each include an entrance surface close to the image source side and an exit surface close to the human eye entrance pupil side;

[0006] The first lens has positive refractive power, and its exit surface is convex;

[0007] The second lens has negative refractive power, its exit surface is concave, and its entrance surface is concave;

[0008] The third lens has positive refractive power, and its entrance surface is convex;

[0009] The fourth lens has negative refractive power;

[0010] The fifth lens has negative refractive power, and its entrance surface is concave;

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

[0012] wherein a display area length IH of the image source matched by the optical lens and an effective focal length f of the optical lens satisfy: 0.9<IH / f<0.95.

[0013] An exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.57<ED / f<0.62.

[0014] Further preferably, a 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: 0.6<f345 / f<0.85.

[0015] Further preferably, a focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.7<f1 / f<7; a light exit surface curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: 0.4<R1 / f<0.9.

[0016] Further preferably, a focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2.5<f2 / f<-0.6; a light exit surface curvature radius R3 of the second lens and a light entrance surface curvature radius R4 of the second lens satisfy:

[0017] -2<R3 / R4<-0.7.

[0018] Further preferably, a focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.3<f3 / f<0.6; a light entrance surface curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: -0.32<R6 / f<-0.22.

[0019] Further preferably, a focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -5<f4 / f<-0.7.

[0020] Further preferably, a focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -200<f5 / f<-0.5; a light entrance surface curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.2<R10 / f<1.6.

[0021] Further preferably, a refractive index Nd2 of the second lens satisfies: 1.75<Nd2<1.9; a refractive index Nd4 of the fourth lens satisfies: 1.7<Nd4<1.85; a refractive index Nd5 of the fifth lens satisfies: 1.75<Nd5<1.9.

[0022] Further preferably, the sum of the center thicknesses of the first lens to the fifth lens along the optical axis ∑CT and the sum of the intervals of any two adjacent lenses of the first lens to the fifth lens on the optical axis ∑AT satisfy:

[0023] 1.8 <∑CT / ∑AT < 6; the sum of the center thicknesses of the first lens to the fifth lens along the optical axis ∑CT and the distance TL of the light exit surface of the first lens to the light entrance surface of the fifth lens on the optical axis satisfy: 0.6 <∑CT / TL < 0.9.

[0024] Further preferably, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -3 < f1 / f2 < -1; the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -0.7 < f3 / f4 < -0.06.

[0025] The application also provides a near-eye display device, which comprises in sequence along the light signal transmission direction: an image source, and the optical lens described above; the image source is used for emitting light signals, and the light signals comprise image information; the optical lens is arranged in the light emission 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 for modulating and transmitting the light signals emitted by the image source to the human eye.

[0026] Compared with the prior art, the optical lens provided by the application has long-focus characteristics through specific surface shape setting and reasonable power distribution, can better present larger local details, and improves the picture quality; meanwhile, the optical lens can realize the refractive power adjustment of -7D to +2D by adjusting the spatial interval distance of the entire lens group and the image source on the optical axis, and has small distortion and high imaging quality under different refractive powers, thereby bringing excellent sensory experience to users. BRIEF DESCRIPTION OF DRAWINGS

[0027] The above and / or additional aspects and advantages of the application will become apparent and be readily understood from the following description, taken in connection with the accompanying drawings, in which:

[0028] Figure 1 FIG. 1 is a structural schematic diagram of a near-eye display device provided in an embodiment of the application.

[0029] Figure 2 FIG. 2 is a structural schematic diagram of an optical lens provided in an embodiment of the application.

[0030] Figure 3 FIG. 3 is a field curvature curve diagram of the optical lens provided in the embodiment 1 of the application.

[0031] Figure 4F-Tan(θ) distortion curve diagram of the optical lens provided in Embodiment 1 of the present application.

[0032] Figure 5 MTF curve diagram of the optical lens provided in Embodiment 1 of the present application.

[0033] Figure 6 Structure schematic diagram of the optical lens provided in Embodiment 2 of the present application.

[0034] Figure 7 Curvature of field curve diagram of the optical lens provided in Embodiment 2 of the present application.

[0035] Figure 8 F-Tan(θ) distortion curve diagram of the optical lens provided in Embodiment 2 of the present application.

[0036] Figure 9 MTF curve diagram of the optical lens provided in Embodiment 2 of the present application.

[0037] Figure 10 Structure schematic diagram of the optical lens provided in Embodiment 3 of the present application.

[0038] Figure 11 Curvature of field curve diagram of the optical lens provided in Embodiment 3 of the present application.

[0039] Figure 12 F-Tan(θ) distortion curve diagram of the optical lens provided in Embodiment 3 of the present application.

[0040] Figure 13 MTF curve diagram of the optical lens provided in Embodiment 3 of the present application.

[0041] Figure 14 Structure schematic diagram of the optical lens provided in Embodiment 4 of the present application.

[0042] Figure 15 Curvature of field curve diagram of the optical lens provided in Embodiment 4 of the present application.

[0043] Figure 16 F-Tan(θ) distortion curve diagram of the optical lens provided in Embodiment 4 of the present application.

[0044] Figure 17 MTF curve diagram of the optical lens provided in Embodiment 4 of the present application.

[0045] Figure 18 Optical path schematic diagram of the near-eye display device provided in Embodiment 5 of the present application.

[0046] The following detailed description will further describe the present application in combination with the above-mentioned drawings. DETAILED DESCRIPTION

[0047] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be noted that these details are merely exemplary of the embodiments of the present application and are intended for purposes of illustration only and are not intended to be limiting in any way. Like reference numerals refer to like elements throughout the specification. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0048] It is noted that, in this specification, the expressions first, second, third, etc. are used only to distinguish one feature from another, and do not denote any limitation on the features. Thus, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0049] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0050] In this specification, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region.

[0051] It is also to be understood that the use of the terms "include", "includes", "including", "comprise", "comprises", "comprising", "have", "has", "having", or "contains" or "containing", when used in this specification, means that there are other items not listed which are also included in the statement, but do not exclude the presence or addition of one or more other features, elements, components, and / or groups thereof. Also, when the expressions such as "at least one of" appear after the list of one or more features, the expression "at least one of" does not modify the individual elements of the list. Also, when describing aspects of the present application, the use of "may" means one or more embodiments of the present application. Also, the expression "exemplary" is intended to mean an example or an illustration.

[0052] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an overly literal or overly formal sense unless expressly so defined herein.

[0053] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other in the case of no conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0054] The present application provides an optical lens, which is used for modulating and transmitting light signals emitted by an image source to an eye entrance pupil side. The optical lens is arranged on a light emitting direction of the image source, that is, an emitting surface of the image source is a light emitting side of the light signals. The optical lens is composed of five lenses, which include, in the reverse direction of light transmission from the eye entrance pupil side to the image source side, a first lens, a second lens, a third lens, a fourth lens and a fifth lens in sequence. The first lens, the second lens, the third lens, the fourth lens and the fifth lens each include an incident surface close to the image source side and an emitting surface close to the eye entrance pupil side. It can be understood that the surface of each lens close to the image source is referred to as the incident surface of the lens, and the surface of each lens close to the eye entrance pupil side is referred to as the emitting surface of the lens. It should be noted that the position of the eye entrance pupil is the diaphragm of the optical lens.

[0055] In some embodiments, the first lens can have a positive focal power, the emitting surface of the first lens is a convex surface, and the incident surface of the first lens is a convex surface or a concave surface. The second lens can have a negative focal power, the emitting surface of the second lens is a concave surface, and the incident surface of the second lens is a concave surface. The third lens can have a positive focal power, the emitting surface of the third lens is a convex surface or a concave surface, and the incident surface of the third lens is a convex surface. The fourth lens can have a negative focal power, the emitting surface of the fourth lens is a convex surface or a concave surface, and the incident surface of the fourth lens is a convex surface or a concave surface. The fifth lens can have a negative focal power, the emitting surface of the fifth lens is a convex surface or a plane, and the incident surface of the fifth lens is a concave surface.

[0056] To meet the wearing needs of users with different refractive degrees, the air gap CT W (i.e., the distance between the incident surface of the fifth lens and the image source on the optical axis) between the entire lens group (composed of the first lens, the second lens, the third lens, the fourth lens and the fifth lens) and the image source on the optical axis can be dynamically adjusted to realize the adjustment of the optical lens between different refractive powers, so as to well meet the wearing needs of users with different refractive degrees. More specifically, the adjustment range of the distance CT W between the incident surface of the fifth lens and the image source on the optical axis satisfies: 3mm < CT W<13mm. Satisfying the above range, the lens can have a large optical back focal length, on the one hand, the light emitted from the image source side has a large bending space, which improves the matching adaptability of the optical lens and the large-size display screen, and at the same time, a large space is reserved between the image source and the optical lens, which is convenient for adjusting the distance between the two, so that a large range (such as -7D to +2D) of diopter adjustment can be realized, which can meet the wearing needs of users with different degrees of myopia or hyperopia. And the diopter adjustment method of the present application is simple, which only needs to move the screen to realize it.

[0057] In some embodiments, the display area length IH of the image source matched by the optical lens and the effective focal length f of the optical lens satisfy: 0.9<IH / f<0.95; the exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.57<ED / f<0.62. Satisfying the above range, the optical lens can match a larger size image source (display screen) to realize high-definition imaging and bring users an excellent sensory experience. At the same time, it is also beneficial to realize the long-focus performance of the lens, which can better present larger local details, making the picture more concentrated and compact, thereby meeting the visual experience of the human eye. And the exit pupil distance ED represents the distance from the eye entrance side to the light exit surface of the first lens on the optical axis, by reasonably controlling the ratio of the exit pupil distance and the focal length, the lens can have a larger entrance pupil distance, reduce the dizziness of the human eye when wearing, and improve the sensory experience.

[0058] In some embodiments, the combined focal length f345 of the third lens, the fourth lens and the fifth lens and the effective focal length f of the optical lens satisfy: 0.6<f345 / f<0.85. Satisfying the above range is beneficial to converge the light emitted from the image source side, so that the light smoothly transitions to the human eye observation area. At the same time, it is also beneficial to correct various aberrations of the optical lens and improve the imaging quality of the optical lens.

[0059] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.7<f1 / f<7; the light exit surface curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: 0.4<R1 / f<0.9. Satisfying the above range can effectively converge the light, so that the emitted light enters the human eye observation area at a relatively parallel viewing angle, providing users with a better immersive experience.

[0060] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2.5<f2 / f<-0.6; the light exit surface curvature radius R3 of the second lens and the light entrance surface curvature radius R4 of the second lens satisfy: -2<R3 / R4<-0.7. Satisfying the above range can appropriately slow down the turning degree of the light, and better disperse the light into the human eye, thereby providing a wide field of view display effect and improving the user's immersion.

[0061] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.3 < f3 / f < 0.6; the radius of curvature R6 of the light entrance surface of the third lens and the effective focal length f of the optical lens satisfy: -0.32 < R6 / f < -0.22. Satisfying the above range is conducive to the convergence of light rays, allowing the light rays 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.

[0062] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -5 < f4 / f < -0.7. Satisfying the above range can greatly diverge the light rays emitted from the image source side to increase the area of the projected virtual image, providing a better immersive experience for the user.

[0063] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -200 < f5 / f < -0.5; the radius of curvature R10 of the light entrance surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.2 < R10 / f < 1.6. Satisfying the above range is conducive to diverging the light rays emitted from the image source side, allowing the outgoing light to enter the human eye observation area with a larger field of view angle, ensuring a large field of view angle while improving the overall imaging quality.

[0064] In some embodiments, the refractive index Nd2 of the second lens satisfies: 1.75 < Nd2 < 1.9; the refractive index Nd4 of the fourth lens satisfies: 1.7 < Nd4 < 1.85; the refractive index Nd5 of the fifth lens satisfies: 1.75 < Nd5 < 1.9. Satisfying the above range, by setting the second, fourth, and fifth lenses to have a larger refractive index, the light rays can be greatly turned, which is conducive to improving the imaging quality.

[0065] In some embodiments, the sum ∑CT of the center thicknesses of the first to fifth lenses along the optical axis and the sum ∑AT of the distances between any two adjacent lenses along the optical axis satisfy: 1.8 < ∑CT / ∑AT < 6; the sum ∑CT of the center thicknesses of the first to fifth lenses along the optical axis and the distance TL between the light exit surface of the first lens and the light entrance surface of the fifth lens along the optical axis satisfy: 0.6 < ∑CT / TL < 0.9. Satisfying the above range can make the structure of the lens more compact, which is conducive to the miniaturization of the lens. At the same time, it is convenient for the mobile image source (display) to adjust the diopter, thereby meeting the wearing needs of users with different diopters.

[0066] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -3 < f1 / f2 < -1; the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -0.7 < f3 / f4 < -0.06. Satisfying the above range, the light rays at the edge of the large field of view can enter the human eye observation area at a more appropriate viewing angle, realizing a large field of view of the lens while satisfying the characteristics of low distortion and high image quality. At the same time, the light rays emitted from the image source side are better converged to enter the human eye observation area at a relatively gentle viewing angle, providing a better immersive experience for the user.

[0067] In some embodiments, the distance TL of the light exit surface of the first lens to the light entrance surface of the fifth lens on the optical axis and the effective focal length f of the optical lens satisfy: 0.9 < TL / f < 1.3; the distance TL of the light exit surface of the first lens to the light entrance surface of the fifth lens on the optical axis and the display area length IH of the image source that can be matched by the optical lens satisfy: 1 < TL / IH < 1.4. Satisfying the above range, the lens has a longer focal length, can better present larger local details, improve the picture quality, and at the same time, the lens has a larger image plane, can match a larger size image source (display screen) to realize high-definition imaging, and bring an excellent sensory experience to the user.

[0068] In some embodiments, the effective aperture DM11 of the light exit surface of the first lens and the effective aperture DM52 of the light entrance surface of the fifth lens satisfy: 0.83 < DM11 / DM52 < 0.95. Satisfying the above range, by reasonably setting the aperture relationship of each lens, the light rays emitted by the display screen can enter the human eye observation area at a relatively parallel and wide viewing angle, ensuring that the system provides a larger eye movement range while improving the experience comfort of the user.

[0069] In some embodiments, the optical lens satisfies the condition formula: 19.5mm < f < 20.3mm; 49.5° < FOV < 50.5°; 18mm < IH < 18.5mm; wherein f represents the effective focal length of the optical lens, FOV represents the maximum field of view of the optical lens, and IH represents the display area length of the image source that can be matched by the optical lens. Satisfying the above range indicates that the optical lens provided by the embodiment of the application has the advantages of small distortion, long focal length, large exit pupil distance, large refractive power adjustable range, and can match a 4K high-resolution screen to realize high-definition imaging.

[0070] In some embodiments, the lens material in the optical lens provided by the present application 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 due to the low dispersion of the glass itself. More specifically, the first lens, the second lens, the fourth lens and the fifth lens can all adopt glass lenses, and the third lens can adopt a glass lens or a plastic lens.

[0071] In some embodiments, the first lens, the second lens, the third lens, the fourth lens and the fifth lens can adopt a spherical lens or an aspherical lens. 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 achieving the miniaturization of the lens. More specifically, the first lens, the second lens, the third lens and the fifth lens all adopt aspherical lenses, and the fourth lens adopts an aspherical lens or a spherical lens.

[0072] In various embodiments of the present application, when the lens adopts an aspherical lens, the shape of each aspherical surface of the optical lens satisfies the following equation:

[0073]

[0074] wherein z is the distance of the curved surface from the vertex of the curved surface in the direction of the optical axis, 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 quadratic surface coefficient, and B, C, D, E, F, G and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order and sixteenth-order surface coefficients, respectively.

[0075] In addition, the present application also provides a near-eye display device, which comprises, in sequence along the direction of light signal transmission, an image source, the optical lens described above, and an image source for emitting light signals, wherein the light signals comprise 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 for modulating and transmitting the light signals emitted by the image source to the human eye.

[0076] The present application will be further described in the following embodiments. In various embodiments, the thickness, the radius of curvature and the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present application, but the embodiments of the present application are not limited to the following embodiments only, and any changes, substitutions, combinations or simplifications made without departing from the innovative points of the present application should be regarded as equivalent replacement methods, and are all included in the protection scope of the present application.

[0077] Embodiment 1

[0078] Please refer to Figure 1The 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.

[0079] Among them, the first lens L1 has positive optical power, the light-exiting surface S1 of the first lens is convex, and the light-incident surface S2 of the first lens is convex.

[0080] The second lens L2 has negative optical power, the light-exiting surface S3 of the second lens is concave, and the light-incident surface S4 of the second lens is concave.

[0081] The third lens L3 has positive optical power, the light-exiting surface S5 of the third lens is concave, and the light-incident surface S6 of the third lens is convex.

[0082] The fourth lens L4 has negative optical power, the light-exiting surface S7 of the fourth lens is convex, and the light-incident surface S8 of the fourth lens is concave.

[0083] The fifth lens L5 has negative optical power, the light-exiting surface S9 of the fifth lens is convex, and the light-incident surface S10 of the fifth lens is concave.

[0084] The first lens L1, the second lens L2, the fourth lens L4, and the fifth lens L5 are all glass aspherical lenses, while the third lens L3 is a plastic aspherical lens.

[0085] 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. WThe distance between the light entrance surface of the fifth lens L5 and the image source 10 on the optical axis) to achieve the adjustment of the optical lens between different diopters, so as to well meet the wearing needs of users with different diopters.

[0086] Specifically, in the embodiment, the distance CT between the light entrance surface of the fifth lens and the image source side on the optical axis is 3.068-6.789 mm, which can realize the diopter adjustment of-700-200 degrees (-7D-2D), so that users with different degrees of myopia or hyperopia can have good sensory experience. As shown in W Fig. 1, which is a structural schematic diagram of the optical lens 100 when the diopter is 0D (0°), at this time CT W is 5.927 mm; when CT W is 3.068 mm, the diopter of the optical lens 100 is-7D (-700°); when CT W is 6.789 mm, the diopter of the optical lens 100 is 2D (200°). The embodiment can realize the diopter adjustment by moving the display screen. Figure 2

[0087] The related parameters of each lens in the optical lens 100 in embodiment 1 are shown in Table 1-1.

[0088] Table 1-1

[0089]

[0090]

[0091] The face type parameters of the aspherical lens of the optical lens 100 in embodiment 1 are shown in Table 1-2.

[0092] Table 1-2

[0093]

[0094] Please refer to Figure 3 , which is a field curvature curve diagram of the optical lens 100, which represents the bending degree of the light rays on the meridional image surface and the sagittal image surface. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within-0.4 mm-0.2 mm, which shows that the optical lens 100 can well correct the field curvature.

[0095] Please refer to Figure 4 , which is a F-Tan(θ) distortion curve diagram of the optical lens 100. The horizontal axis in the figure represents the F-Tan(θ) distortion percentage, and the vertical axis represents the half field angle (unit: degree). From Figure 4 ​It can be seen from the figure that the F-Tan(θ) distortion value of the image height received by the user's eyes is controlled within ±2%, which indicates that the distortion of the optical lens 100 is well corrected.

[0096] Please refer to Figure 5 , which is an MTF (Modulation Transfer Function) curve diagram of the optical lens 100, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value of the present embodiment is above 0.8 in the full field of view, and the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low and high frequency cases.

[0097] It can be seen from Figure 3 , Figure 4 , Figure 5 that the aberration of the optical lens 100 is well balanced, and has good imaging quality.

[0098] Embodiment 2

[0099] Please refer to Figure 6 , which is a structural schematic diagram of the optical lens 200 provided in the embodiment 2 of the present application. Compared with the embodiment 1, the main difference is that: the light entrance surface S2 of the first lens L1 is a concave surface; the light exit surface S7 of the fourth lens L4 is a concave surface; the light entrance surface S8 of the fourth lens L4 is a convex surface; the light exit surface S9 of the fifth lens L5 is a plane; the third lens L3 adopts a glass aspherical lens; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0100] In the present embodiment, the distance CT W between the light entrance surface of the fifth lens and the image source side on the optical axis is adjusted in the range of 8.746-12.847mm. As shown in Figure 6 , which is a structural schematic diagram of the optical lens 200 when the diopter is 0D (0°), at this time CT W is 11.987mm; when CT W is 8.746mm, the diopter of the optical lens 200 is -7D (-700°); when CT W is 12.847mm, the diopter of the optical lens 200 is 2D (200°).

[0101] The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in Table 2-1.

[0102] Table 2-1

[0103]

[0104] The surface shape parameters of the aspherical lenses of the optical lens 200 in embodiment 2 are shown in table 2-2.

[0105] Table 2-2

[0106]

[0107]

[0108] Please refer to Figure 7 , which is a field curvature curve diagram of the optical lens 200, indicating the bending degree of light rays on the meridional image surface and the sagittal image surface, 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 image surface and the sagittal image surface is controlled within ±0.4 mm, which shows that the optical lens 200 can better correct the field curvature.

[0109] Please refer to Figure 8 , which is an F-Tan(θ) distortion curve diagram of the optical lens 200, in which the horizontal axis represents the F-Tan(θ) distortion percentage, and the vertical axis represents the half field of view (unit: degree). As can be seen from Figure 8 , the F-Tan(θ) distortion value of the image height received by the user's eye is controlled within -4%~0%, which shows that the distortion of the optical lens 200 is well corrected.

[0110] Please refer to Figure 9 , which is an MTF (Modulation Transfer Function) curve diagram of the optical lens 200, indicating the lens imaging modulation degree of different spatial frequencies under each field 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 the present embodiment is above 0.7 in the full field of view, and the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in low and high frequency conditions.

[0111] As can be seen from Figure 7 , Figure 8 , Figure 9 , the aberration of the optical lens 200 is well balanced, and has good imaging quality.

[0112] Embodiment 3

[0113] Please refer to Figure 10 , which is a structural schematic diagram of the optical lens 300 provided in embodiment 3 of the present application. Compared with embodiment 1, the main difference is that the third lens L3 adopts a glass aspherical lens; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0114] In the present embodiment, the distance CTW The adjustment range of CT is 5.331-9.027 mm. As shown in FIG. 3B, which is a structural schematic diagram of the optical lens 300 at a dioptric power of 0D (0°), the CT is 8.174 mm; when the CT is 5.331 mm, the dioptric power of the optical lens 300 is -7D (-700°); and when the CT is 9.027 mm, the dioptric power of the optical lens 300 is 2D (200°). W W W Figure 10

[0115] The related parameters of the lenses in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0116] Table 3-1

[0117]

[0118]

[0119] The surface type parameters of the aspherical lenses of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0120] Table 3-2

[0121]

[0122] Please refer to FIG. 4, which is a field curvature curve diagram of the optical lens 300, indicating the bending degree of light rays on the sagittal image plane and the tangential image plane, wherein 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 diagram, the field curvature of the sagittal image plane and the tangential image plane is controlled within -0.4 mm-0.2 mm, which indicates that the optical lens 300 can better correct the field curvature. Figure 11 Please refer to FIG. 5, which is an F-Tan(θ) distortion curve diagram of the optical lens 300, wherein the horizontal axis represents the F-Tan(θ) distortion percentage, and the vertical axis represents the half field of view (unit: °). As can be seen from the diagram, the F-Tan(θ) distortion value at the image height received by the user's eye is controlled within ±2%, which indicates that the distortion of the optical lens 300 is well corrected.

[0123] Figure 12 Please refer to FIG. 6, which is an F-Tan(θ) distortion curve diagram of the optical lens 300, wherein the horizontal axis represents the F-Tan(θ) distortion percentage, and the vertical axis represents the half field of view (unit: °). As can be seen from the diagram, the F-Tan(θ) distortion value at the image height received by the user's eye is controlled within ±2%, which indicates that the distortion of the optical lens 300 is well corrected. Figure 12

[0124] Please refer to FIG. 6, which is an F-Tan(θ) distortion curve diagram of the optical lens 300, wherein the horizontal axis represents the F-Tan(θ) distortion percentage, and the vertical axis represents the half field of view (unit: °). As can be seen from the diagram, the F-Tan(θ) distortion value at the image height received by the user's eye is controlled within ±2%, which indicates that the distortion of the optical lens 300 is well corrected. Figure 13 ​​​​​​Figure 3 shows a MTF (Modulation Transfer Function) curve of the optical lens 300, which represents the lens imaging modulation degree of different spatial frequencies under each field of view, the horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.8 in the full field of view, and the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low and high frequency cases.

[0125] From Figure 11 , Figure 12 , Figure 13 it can be seen that the aberration of the optical lens 300 is well balanced, and has good imaging quality.

[0126] Embodiment 4

[0127] Please refer to Figure 14 , which shows a structural schematic diagram of an optical lens 400 provided in Embodiment 4 of the present application. Compared with Embodiment 1, the main difference is that: the light entrance surface S2 of the first lens L1 is a concave surface; the light exit surface S5 of the third lens L3 is a convex surface; the light exit surface S7 of the fourth lens L4 is a concave surface; the light entrance surface S8 of the fourth lens L4 is a convex surface; the light exit surface S9 of the fifth lens L5 is a plane; the third lens L3 adopts a glass aspheric lens; the fourth lens L4 adopts a glass spherical lens; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0128] In this embodiment, the distance CT W between the light entrance surface of the fifth lens and the image source side on the optical axis is 6.652-10.297mm. As Figure 14 shown, when the dioptric power of the optical lens 400 is 0D (0°), the distance CT W is 9.451mm; when the distance CT W is 6.652mm, the dioptric power of the optical lens 400 is -7D (-700°); when the distance CT W is 10.297mm, the dioptric power of the optical lens 400 is 2D (200°).

[0129] The related parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0130] Table 4-1

[0131]

[0132] The surface type parameters of the aspheric lens of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0133] Table 4-2

[0134]

[0135]

[0136] 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 to 0.8 mm, indicating that optical lens 400 can correct field curvature well.

[0137] 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 at the high point of the image received by the user's eye is controlled within ±2%, indicating that the distortion of the optical lens 400 has been well corrected.

[0138] Please refer to Figure 17 The 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 0.5 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.

[0139] 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.

[0140] 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.

[0141] Table 5

[0142]

[0143]

[0144] In summary of the above embodiments, the optical lens provided by the application has at least the following advantages:

[0145] (1) By means of specific surface shape setting and reasonable power distribution, the optical lens has long-focus characteristics, can better present larger local details, and improve picture quality, and meanwhile, the optical lens has low distortion characteristics, improves imaging quality, and brings better experience to users.

[0146] (2) Diopter adjustment (-7D to +2D) can be realized by moving the screen, and all have high imaging quality, can meet the needs of different myopic or hyperopic users, and can provide better experience to users.

[0147] (3) The optical lens adopts five lenses, has small total length in design, has few lenses, and has simple surface shape, meets the development trend of miniaturization and light weight.

[0148] Embodiment 5

[0149] Please refer to Figure 18 , which is a light path schematic diagram of a near-eye display device 500 provided by an embodiment of the application, the near-eye display device 500 comprising an image source 10 and the optical lens (such as the optical lens 100) in any one of the preceding embodiments of the application, the optical lens 100 being located between the human eye 20 and the image source 10. Image information emitted from the image source 10 enters the human eye 20 to form an image through the optical lens 100, and a high-definition magnified virtual image can be observed in the human eye 20, which has extremely realistic sensory experience.

[0150] The image source 10 is used for emitting light signals, and the light signals comprise image information. Specifically, the image source 10 can be one of Micro LED, OLED, LCD, LCOS, M-OLED and the like, and can provide high-definition image picture information for the optical lens 100.

[0151] The optical lens 100 is arranged on the light-emitting direction of the image source 10, and the fifth lens in the optical lens 100 is arranged closer to the image source 10 than the first lens, and the optical lens 100 is used for modulating and transmitting the light signals emitted by the image source 10 to the human eye 20.

[0152] The near-eye display device 500 can be a VR glasses, a VR helmet, a head-mounted display device, etc. By adjusting the distance between the lens and the image source side, the diopter can be adjusted (-7D~2D), so that users with different degrees of myopia or hyperopia can have a good experience. Because the above-mentioned optical lens has a long-focus characteristic, and the optical lens has the characteristics of low distortion, the imaging quality is improved, and the user has a better experience. At the same time, the optical lens also has a larger image surface and higher resolving power, and the light signal image modulated by the optical lens is bright and clear, and the effect is better, and the picture projected to the human eye is clearer, so the near-eye display device equipped with the optical lens at least has the characteristics of small distortion and high image quality, which can effectively improve the visual experience and comfort of the user.

[0153] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like 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 application. In the present specification, the illustrative description of the above terms does 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.

[0154] The above-described embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but should not be understood as a limitation on the scope of the patent of the present application. It should be noted that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to 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 emergent light surface close to the side of the entrance pupil of the human eye; The first lens has a positive optical power, and its emergent light surface is convex; The second lens has a negative optical power, its emergent light surface is concave, and its incident light surface is concave; The third lens has a positive optical power, and its incident light surface is convex; The fourth lens has a negative optical power; 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 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: 0.9 < IH / f < 0.95; The exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.57 < ED / f < 0.

62.

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: 0.6 < f345 / f < 0.

85.

3. 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: 0.7 < f1 / f < 7; the curvature radius R1 of the emergent light surface of the first lens and the effective focal length f of the optical lens satisfy: 0.4 < R1 / f < 0.

9.

4. 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: -2.5 < f2 / f < -0.6; the curvature radius R3 of the emergent light surface of the second lens and the curvature radius R4 of the incident light surface of the second lens satisfy: -2 < R3 / R4 < -0.

7.

5. 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: 0.3 < f3 / f < 0.6; the curvature radius R6 of the incident light surface of the third lens and the effective focal length f of the optical lens satisfy: -0.32 < R 6. The optical lens according to claim 1, characterized in that, ​ 7. The optical lens according to claim 1, characterized in that, ​ 8. The optical lens according to claim 1, characterized in that, ​ 9. The optical lens according to claim 1, characterized in that, 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: 1.8 < ∑CT / ∑AT < 6; 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: 0.6 < ∑CT / TL < 0.

9.

10. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -3 < f1 / f2 < -1; the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -0.7 < f3 / f4 < -0.

06.

11. A near-eye display device, characterized in that, In the light signal transmission direction, it sequentially includes: an image source, and 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 disposed in the light-emitting direction of the image source, and the fifth lens is disposed 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