Optical Imaging Lens Group, Scanning Display Device, and Near-Eye Display Device

Abstract

Embodiments of the present application disclose an optical imaging lens group, a scanning display device, and a near-eye display device, which relate to the technical field of scanning displays. By reasonably optimizing the focal lengths of five coaxial lenses of the optical imaging lens group, the optical power of the system can be reasonably dispersed, the aberration generated by the lenses can be reduced, and the purpose of correcting various aberrations can be achieved, so as to achieve clear imaging of the image-side curved surface on the basis of increasing the field of view angle; by limiting and optimizing the refractive index, dispersion coefficient, and surface structure of the five coaxial lenses, the field of view angle and imaging quality are further improved; by limiting and optimizing the design of the five coaxial lenses to an aspherical surface structure, on the basis of further improving the imaging quality, the overall structural configuration of the optical imaging lens group can be more compact, meeting the production requirements of miniaturization of lens products.

Description

Technical Field

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

[0002] As a new display technology, scanning display imaging can be used in various application scenarios such as projection display and near-eye display.

[0003] However, in the existing scanning display imaging system, there are disadvantages such as high processing difficulty, high mass production cost, poor imaging quality, small field of view angle, and inability to combine miniaturization. As a result, the scanning display imaging technology is subject to certain limitations in the process of market promotion and application. Especially when the scanning display imaging is applied to the near-eye display scenario, due to the influence of imaging effect and field of view angle, it has always been unable to meet the high-resolution performance requirements in near-eye display, thus hindering the development of near-eye display towards the consumer market. Summary of the Invention

[0004] The purpose of the present application is to provide an optical imaging lens group, a scanning display device, and a near-eye display device to meet the requirements of large field of view angle, high imaging quality, and miniaturization in the near-eye display scenario.

[0005] An embodiment of the present application provides an optical imaging lens group, which at least includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens that are coaxially arranged in sequence from the first side to the second side. The focal lengths corresponding to the first lens to the fifth lens are positive, negative, positive, positive, and positive respectively.

[0006] Optionally, 2.49 ≤ f1 / f ≤ 2.69, where f1 is the focal length of the first lens and f is the focal length of the optical imaging lens group;

[0007] The second side surface of the fifth lens is concave near the optical axis.

[0008] Optionally, the following relationships are satisfied for each of the lenses: -0.96 ≤ f2 / f ≤ -0.41, 0.59 ≤ f3 / f ≤ 3.14, 0.91 ≤ f4 / f ≤ 0.97, and 8.98 ≤ f5 / f ≤ 19.23; where f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, and f is the focal length of the optical imaging lens group;

[0009] Each of the lenses also satisfies the following relationships: 1.49 ≤ n1 ≤ 1.59, 1.74 ≤ n2 ≤ 1.76, 1.6 ≤ n3 ≤ 1.62, 1.49 ≤ n4 ≤ 1.56, 1.62 ≤ n5 ≤ 1.74; where n1 is the refractive index of the first lens, n2 is the refractive index of the second lens, n3 is the refractive index of the third lens, n4 is the refractive index of the fourth lens, and n5 is the refractive index of the fifth lens;

[0010] The dispersion coefficients of each of the lenses satisfy: 43.2 ≤ v1 ≤ 70.4, 27.6 ≤ v2 ≤ 28.3, 60.1 ≤ v3 ≤ 60.3, 64 ≤ v4 ≤ 70.4, 44.9 ≤ v5 ≤ 60.3; where v1 is the Abbe number of the first lens, v2 is the Abbe number of the second lens, v3 is the Abbe number of the third lens, v4 is the Abbe number of the fourth lens, and v5 is the Abbe number of the fifth lens.

[0011] [[ID=X6]]Optionally, n1 is 1.49 or 1.59, n2 is 1.74 or 1.76, n3 is 1.60 or 1.62, n4 is 1.49 or 1.54 or 1.56, and n5 is 1.62 or 1.74;

[0012] The dispersion coefficients of each of the lenses satisfy: the Abbe number of the first lens is 43.2 or 61.4 or 70.4, the Abbe number of the second lens is 27.6 or 28.3, the Abbe number of the third lens is 60.1 or 60.3, the Abbe number of the fourth lens is 64 or 65.1 or 70.4, and the Abbe number of the fifth lens is 44.9 or 60.3.

[0013] Optionally, the first side surface of the fifth lens is convex; the first side surface of the fourth lens is convex, and the second side surface of the fourth lens is convex near the optical axis.

[0014] Optionally, the first side surface of the first lens is convex, and the second side surface of the first lens is concave or convex.

[0015] Optionally, the first side surface of the second lens is concave or convex, and the second side surface of the second lens is concave; the first side surface of the third lens is convex near the optical axis, and the second side surface of the third lens is concave;

[0016] The first side surfaces and the second side surfaces of the first lens to the fifth lens are all aspherical surface structures;

[0017] The second side of the optical imaging lens group corresponds to a curved surface image, and the first side of the optical imaging lens group corresponds to a planar image.

[0018] In an embodiment of the present application, a scanning display device is further provided, which includes an optical fiber scanner and the aforementioned optical imaging lens group. The optical fiber scanner is used to scan and emit the light of the image to be displayed, and the optical imaging lens group is used to magnify and project the scanning plane corresponding to the light emitted by the optical fiber scanner;

[0019] Among them, the optical fiber scanner includes an actuator and an optical fiber fixed on the actuator. The part of the optical fiber exceeding the actuator forms an optical fiber cantilever, and the optical fiber cantilever performs two-dimensional scanning under the drive of the actuator.

[0020] In an embodiment of the present application, a near-eye display device is further provided. The near-eye display device is used as a head-mounted augmented reality device and at least includes a near-eye display module and the scanning display device according to the above. The scanning display device is arranged in the near-eye display module.

[0021] In an embodiment of the present application, a near-eye display device is further provided. The near-eye display device is used as a head-mounted virtual reality device and at least includes a near-eye display module and the scanning display device according to the above. The scanning display device is arranged in the near-eye display module.

[0022] By adopting the technical solution in the embodiment of the present application, the following technical effects can be achieved:

[0023] In the embodiment of the present application, by reasonably optimizing the focal lengths of the five coaxial lenses of the optical imaging lens group, the optical power of the system can be reasonably dispersed, the aberration generated by the lens can be reduced, and the purpose of correcting various aberrations can be achieved, so as to achieve clear imaging of the image-side curved surface on the basis of increasing the field of view angle; at the same time, the overall structure of the optical imaging lens group is made more compact by configuring a reasonable number of lens combinations, meeting the production requirements of miniaturization of lens products.

[0024] Furthermore, by limiting and optimizing the refractive index, dispersion coefficient and surface structure of the five coaxial lenses, the field of view angle and imaging quality are further improved.

[0025] Other features and advantages of the present application will be described in the following specification, and part of them will become obvious from the specification or be understood by implementing the technical solution of the present application. The objectives and other advantages of the present application can be realized and obtained through the structures and / or processes specifically pointed out in the specification, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, objectives and advantages of the present application will become more obvious:

[0027] Figure 1a 、1b It is a schematic structural diagram of an illustrative scanning display system;

[0028] Figure 2a It is a schematic diagram of the scanning output of the fiber optic scanner provided by an embodiment of the present application;

[0029] Figure 2b It is a schematic diagram of the positional relationship between the optical imaging lens group provided by an embodiment of the present application and the entrance pupil position, exit pupil position, and the corresponding exit pupil distance;

[0030] Figure 3 It is a schematic structural diagram of an optical imaging lens group provided by Embodiment 1 of the present application;

[0031] Figure 4 It is the MTF curve graph of the optical imaging lens group in Embodiment 1 of the present application;

[0032] Figure 5 It is the field curvature and distortion curve graph of the optical imaging lens group in Embodiment 1 of the present application;

[0033] Figure 6 It is the lateral chromatic aberration graph of the optical imaging lens group in Embodiment 1 of the present application.

[0034] Figure 7 It is a schematic structural diagram of an optical imaging lens group provided by Embodiment 2 of the present application;

[0035] Figure 8 It is the MTF curve graph of the optical imaging lens group in Embodiment 2 of the present application;

[0036] Figure 9 It is the field curvature and distortion curve graph of the optical imaging lens group in Embodiment 2 of the present application;

[0037] Figure 10 It is the lateral chromatic aberration graph of the optical imaging lens group in Embodiment 2 of the present application;

[0038] Figure 11 It is a schematic structural diagram of an optical imaging lens group provided by Embodiment 3 of the present application;

[0039] Figure 12 It is the MTF curve graph of the optical imaging lens group in Embodiment 3 of the present application;

[0040] Figure 13 It is the field curvature and distortion curve graph of the optical imaging lens group in Embodiment 3 of the present application;

[0041] Figure 14 It is the lateral chromatic aberration graph of the optical imaging lens group in Embodiment 3 of the present application;

[0042] Figure 15 It is a schematic structural diagram of an optical imaging lens group provided by Embodiment 4 of the present application;

[0043] Figure 16 is the MTF curve graph of the optical imaging lens group in Embodiment 4 of the present application;

[0044] Figure 17 is the field curvature and distortion curve graph of the optical imaging lens group in Embodiment 4 of the present application;

[0045] Figure 18 is the lateral chromatic aberration graph of the optical imaging lens group in Embodiment 4 of the present application.

[0046] Icon: 100 - Processor; 110 - Laser group; 120 - Fiber optic scanning module; 130 - Transmission fiber; 140 - Light source modulation circuit; 150 - Scanning drive circuit; 160 - Beam combining unit; 121 - Scanning actuator; 121a - Slow axis; 121b - Fast axis; 122 - Fiber optic cantilever; 123 - Lens group; 124 - Scanner package housing; 125 - Fixing part; 230 - Scanning surface; 240 - Imaging plane; 11 - First lens; 12 - Second lens; 13 - Third lens; 14 - Fourth lens; 15 - Fifth lens; 01 - Aperture; 02 - Scanning surface; 31 - First lens; 32 - Second lens; 33 - Third lens; 34 - Fourth lens; 35 - Fifth lens; 03 - Aperture; 04 - Scanning surface; 51 - First lens; 52 - Second lens; 53 - Third lens; 54 - Fourth lens; 55 - Fifth lens; 05 - Aperture; 06 - Scanning surface; 71 - First lens; 72 - Second lens; 73 - Third lens; 74 - Fourth lens; 75 - Fifth lens; 76 - Sixth lens; 07 - Aperture; 08 - Scanning surface. Detailed implementation manners

[0047] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than limiting the invention. Additionally, it should be noted that for the sake of description, only parts related to the relevant invention are shown in the drawings.

[0048] Explanatory Scanning Display System

[0049] For current scanning display imaging, it can be implemented by a Digital Micromirror Device (DMD) or a Fiber Scanning Display (FSD) device. Among them, the FSD scheme, as a new type of scanning display imaging method, realizes the scanning output of images through a fiber optic scanner. In order to enable those skilled in the art to clearly understand the solution of the present application, the brief principle and corresponding system of fiber optic scanning imaging will be elaborated below.

[0050] AsFigure 1a As shown, an illustrative scanning display system in the present application mainly includes:

[0051] A processor 100, a laser group 110, an optical fiber scanning module 120, a transmission optical fiber 130, a light source modulation circuit 140, a scanning drive circuit 150, and a beam combining unit 160. Among them,

[0052] The processor 100 can be a Graphics Processing Unit (GPU), a Central Processing Unit (CPU), or other chips or circuits with control functions and image processing functions, and specific limitations are not made here.

[0053] When the system works, the processor 100 can control the light source modulation circuit 140 to modulate the laser group 110 according to the image data to be displayed. The laser group 110 includes multiple monochromatic lasers that emit beams of different colors. As can be seen from FIG. 1, red (R), green (G), and blue (B) lasers can be specifically used in the laser group. The beams emitted by the lasers in the laser group 110 are combined into a single laser beam by the beam combining unit 160 and coupled into the transmission optical fiber 130.

[0054] The processor 100 can also control the scanning drive circuit 150 to drive the optical fiber scanner in the optical fiber scanning module 120 to scan, so as to scan and output the beam transmitted in the transmission optical fiber 130.

[0055] The beam scanned and output by the optical fiber scanner acts on a pixel position on the surface of the medium, and a light spot is formed at this pixel position, thus realizing the scanning of this pixel position. Driven by the optical fiber scanner, the output end of the transmission optical fiber 130 scans according to a certain scanning trajectory, so that the beam moves to the corresponding pixel position. In the actual scanning process, the beam transmitted by the transmission optical fiber 130 will form a light spot with corresponding image information (such as color, gray level, or brightness) at each pixel position. In the time of one frame, the beam traverses each pixel position at a high enough speed to complete the scanning of one frame of the image. Due to the characteristic of "visual persistence" when the human eye observes things, the human eye cannot perceive the movement of the beam at each pixel position, but sees a complete frame of the image.

[0056] Continue to refer to Figure 1b, which is the specific structure of the fiber optic scanning module 120, including: a scanning actuator 121, a fiber optic cantilever 122, a lens group 123, a scanner encapsulation housing 124, and a fixing member 125. The scanning actuator 121 is fixed in the scanner encapsulation housing 124 through the fixing member 125. The transmission fiber 130 extends at the front end of the scanning actuator 121 to form a fiber optic cantilever 122 (also referred to as a scanning fiber). During operation, under the drive of a scanning drive signal, the slow axis 121a (also referred to as the first actuation part) of the scanning actuator 121 vibrates in the vertical direction (this vertical direction is parallel to Figure 1a , 1b the Y-axis in the reference coordinate system in Figure 1a , 1b and in this application, this vertical direction can also be referred to as the first direction), and its fast axis 121b (also referred to as the second actuation part) vibrates in the horizontal direction (this horizontal direction is parallel to

[0057] such as Figure 2a shown, the X-axis in the reference coordinate system in

[0058] and in this application, this horizontal direction can also be referred to as the second direction). Driven by the scanning actuator 121, the front end of the fiber optic cantilever 122 performs two-dimensional scanning and emits a light beam along a preset trajectory, and the emitted light beam can pass through the lens group 123 to achieve scanning imaging. Generally, the structure formed by the scanning actuator 121 and the fiber optic cantilever 122 can be referred to as: a fiber optic scanner. Figure 2a As shown in

[0059] Figure 2a in the embodiment of this application, through the movement of the fast and slow axes, the movement trajectory of the fiber optic light output end forms a scanning surface 230, and after passing through the corresponding lens group 123, it is converted into an imaging plane 240. When applied to a near-eye display device such as an augmented reality (AR) device, the imaging plane 240 will be used as the entrance pupil of the waveguide and coupled into the waveguide for imaging for the human eye to view.

[0058] For the convenience of description and to make it easy for those skilled in the art to understand the solution of this application, it should be noted that the optical imaging lens group in this application (such as Figure 2a the lens group 123 shown in

[0059] Figure 2a ) acts as an eyepiece. Through the action of this optical imaging lens group, the scanning surface 230 can be converted into an imaging plane 240 (in actual application, the light transmission direction is: from the scanning surface 230 to the imaging plane 240). Therefore, on the side of the optical imaging lens group corresponding to the imaging plane 240, it is called the first side, and on the side of the optical imaging lens group corresponding to the scanning surface 230, it is called the second side. In the following content, the "first side" and "second side" will be used as references to describe the embodiment solutions of the optical imaging lens group. And in the subsequent embodiments, the description, such as for a certain lens in the optical imaging lens group, the "first side surface of the Xth lens" refers to the surface of the Xth lens facing the first side.It should be further noted that in the projection field, the image corresponding to the first side is a planar image, and the corresponding planar image carrier can be a projection screen, a curtain, a wall surface, etc. The image corresponding to the second side is a curved surface image, that is, an arc-shaped scanning surface scanned by an optical fiber scanner or emitted by other image sources; in the use scenario of the imaging field, the optical path is opposite to that in the projection field. Generally, the first side corresponds to the object side for collecting image information, and the second side generally corresponds to the image side obtained by imaging.

[0060] Optical Imaging Lens Group

[0061] The optical imaging lens group in the embodiment of the present application at least includes: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, which are coaxially arranged in sequence from the first side to the second side, with a total of five lenses. It should be noted that the focal lengths of the first lens to the fifth lens in the embodiment of the present application are positive, negative, positive, positive, and positive respectively. It should be noted that by reasonably optimizing the positive and negative properties of the focal lengths of the five coaxial lenses at the same time, the optical power of the system can be reasonably dispersed, the aberration generated by the lens can be reduced, and the purpose of correcting various aberrations can be achieved, so as to achieve clear imaging of the image-side curved surface on the basis of increasing the field of view. In addition, it should be emphasized that the focal length of the fifth lens is set to be positive, which can enhance the converging ability of the curved surface image to balance the aberration.

[0062] Further specifically and preferably, the various lenses satisfy the following relationships: 2.49≤f1 / f≤2.69, -0.96≤f2 / f≤-0.41, 0.59≤f3 / f≤3.14, 0.91≤f4 / f≤0.97, and 8.98≤f5 / f≤19.23; where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, and f is the focal length of the optical imaging lens group (which can also be understood as the equivalent focal length of the optical imaging lens group). It should be noted that by more specifically defining the focal length of each lens, the optical power of the system is more reasonably dispersed and configured, thereby further strengthening the correction of various aberrations, improving the field of view and imaging quality. In addition, if the regional position of the lens focal length is not defined in this embodiment, it means that the focal length of the lens can be the focal length of the lens near the optical axis. It should be emphasized that before the applicant made this invention, the existing optical imaging lens group for projection display could not achieve the balance between imaging quality and a large field of view, that is, usually the imaging quality would be reduced when the field of view was increased, and it was impossible to achieve a large field of view while ensuring the imaging quality. The inventive solution of the present application realizes high-quality imaging output while increasing the field of view and being miniaturized through the combined control of the focal lengths and surface shapes of the five lenses.

[0063] Further, in a possible implementation, the five lenses can be connected in a spaced manner or bonded together by adhesion, which will be determined according to the actual application requirements and is not limited here.

[0064] Further, in a possible implementation, the above various lenses also satisfy the following relationship:

[0065] 1.49 ≤ n1 ≤ 1.59, 1.74 ≤ n2 ≤ 1.76, 1.6 ≤ n3 ≤ 1.62, 1.49 ≤ n4 ≤ 1.56, 1.62 ≤ n5 ≤ 1.74; where n1 is the refractive index of the first lens, n2 is the refractive index of the second lens, n3 is the refractive index of the third lens, n4 is the refractive index of the fourth lens, and n5 is the refractive index of the fifth lens. Preferably, n1 is 1.49 or 1.59, n2 is 1.74 or 1.76, n3 is 1.60 or 1.62, n4 is 1.49 or 1.54 or 1.56, and n5 is 1.62 or 1.74. It should be noted that by limiting the refractive indices of the five lenses through optimized design, the dispersion coefficient of the corresponding lens can be reasonably controlled to ensure imaging quality and a large field of view.

[0066] Further optionally, in order to better ensure imaging quality, the embodiments of the present invention specifically preferably limit the dispersion coefficients of the five lenses, and the dispersion coefficients of various lenses satisfy: 43.2 ≤ v1 ≤ 70.4, 27.6 ≤ v2 ≤ 28.3, 60.1 ≤ v3 ≤ 60.3, 64 ≤ v4 ≤ 70.4, 44.9 ≤ v5 ≤ 60.3; where v1 is the Abbe number of the first lens, v2 is the Abbe number of the second lens, v3 is the Abbe number of the third lens, v4 is the Abbe number of the fourth lens, and v5 is the Abbe number of the fifth lens. Specifically preferably limited to: the Abbe number of the first lens is 43.2 or 61.4 or 70.4, the Abbe number of the second lens is 27.6 or 28.3, the Abbe number of the third lens is 60.1 or 60.3, the Abbe number of the fourth lens is 64 or 65.1 or 70.4, and the Abbe number of the fifth lens is 44.9 or 60.3. It should be noted that in other embodiments of the present invention, it is not limited to the Abbe numbers of the five lenses defined in the embodiments of the present invention, and other dispersion coefficients that can ensure a good matching relationship between the five lenses can also be used to ensure the final imaging quality.

[0067] Further optionally, in a possible implementation manner, the first side surface of the first lens is a convex surface, and the second side surface of the first lens is a concave surface or a convex surface; the first side surface of the second lens is a concave surface or a convex surface, and the second side surface of the second lens is a concave surface; the first side surface of the third lens is a convex surface near the optical axis, and the second side surface of the third lens is a concave surface; the first side surface of the fourth lens is a convex surface, and the second side surface of the fourth lens is a convex surface near the optical axis; the first side surface of the fifth lens is a convex surface, and the second side surface of the fifth lens is a concave surface near the optical axis. It should be noted that by defining the surface type structures of the corresponding side surfaces of the above lenses, the aberration generated between the lenses can be further effectively corrected, the optical sensitivity can be reduced, and the final imaging quality and the field of view angle can be improved. In addition, it should be noted that when it is said that the first side surface is a convex surface in this article, it means that the first side surface forms a convex shape toward the first side direction of the optical imaging lens group; when the first side surface is a concave surface, it means that the first side surface forms a concave shape toward the first side direction of the optical imaging lens group; when the second side surface is a convex surface, it means that the second side surface forms a convex shape toward the second side direction of the optical imaging lens group; when the second side surface is a concave surface, it means that the second side surface forms a concave shape toward the second side direction of the optical imaging lens group. It should be emphasized that in other embodiments of the present invention, it is not limited to simultaneously defining the surface type structures of all lenses as in this embodiment, and it is also possible to only define the surface type structures of at least one of the lenses, such as only defining the surface type structures of the first side surface and the second side surface of the fifth lens, and not defining the surface type structures of the other lenses.

[0068] Further, in some implementation manners, the surface type of the lens is not that the entire side surface is a concave surface or a convex surface. The surface type of the lens may be a composite curved surface, or the part near the optical axis is a curved surface while the edge part is not a curved surface; in particular, optionally, when the lens surface is a convex surface and the position of the convex surface is not defined, it means that the convex surface can be located near the optical axis of the lens surface; similarly, when the lens surface is a concave surface and the position of the concave surface is not defined, it means that the concave surface can be located near the optical axis of the lens surface.

[0069] Further optionally, in a possible implementation manner, the first side surfaces and the second side surfaces of the first lens to the fifth lens are all aspherical surface type structures. It should be noted that by defining the mirror surface structures of the first lens to the fifth lens as aspherical surface type structures, more control variables can be obtained to reduce aberration and reasonably reduce the number of lenses. Therefore, on the basis of improving the image display quality, it is also helpful for the miniaturization or micro-miniaturization of the optical imaging lens group. In addition, when it is said that the first side surfaces and the second side surfaces of the above lenses are all aspherical surface type structures, it can be understood that the entire or a part of the optically effective area of the lens surface is aspherical.

[0070] Further optionally, in a possible implementation, the first lens to the fifth lens are all made of plastic or glass. It should be noted that the first lens to the fifth lens made of plastic can effectively reduce the production cost. Compared with the glass material, the cost of the plastic lens is one-twentieth to one-tenth of the glass material cost, so it is very conducive to low-cost mass production. In addition, the plastic lens can usually be injection-molded, with low processing difficulty and can be easily processed into various aspherical surface structures, and at the same time, the plastic material can also reduce the weight of the lens as a whole, which is beneficial to its lightweight product design. When using glass material, the refractive index of the glass material is higher and wider, which has an advantage in correcting lens aberration; the expansion coefficient of the glass material is much smaller, which is beneficial to precise assembly. In addition, due to the high temperature resistance, ultraviolet resistance and acid and alkali resistance of the glass itself, the service life and performance stability of the lens group have strong advantages. Of course, it should be emphasized that in other embodiments of the present invention, it is not limited to the two materials of plastic and glass provided in the embodiments of the present invention, and it can also be other materials capable of making lenses.

[0071] It should also be noted that the optical imaging lens group disclosed in the embodiments of the present invention can optionally be provided with at least one aperture stop, which can be located in front of the first lens (the first side), between the lenses, or behind the last fifth lens (the second side). The type of the aperture stop can be an aperture stop or a field stop, etc., which can be used to reduce stray light and help improve the image display quality.

[0072] Furthermore, in some embodiments, the optical imaging lens group in the embodiments of the present application also satisfies the following optical characteristics:

[0073] The multiple lenses in the optical imaging lens group are arranged coaxially in sequence from the entrance pupil position to the exit pupil position. The exit pupil position of the optical imaging lens group corresponds to the curved surface image, that is, it corresponds to the second side of the optical imaging lens group; the entrance pupil position of the optical imaging lens group corresponds to the planar image, that is, it corresponds to the first side of the optical imaging lens group. It should be noted that, please refer to Figures 1a to 2b ( Figure 2b taking the optical imaging lens group including 6 lenses as an example), the lens surface that is close to and opposite to the exit pupil position among the multiple lenses (that is, the lens surface closest to the curved surface image) is concave, and the optical axis intersects the concave surface to form an intersection point. The distance between the intersection point and the exit pupil position is the exit pupil distance, and the exit pupil distance is 1.5 - 6.0 mm. Preferably, the exit pupil distance is 2 - 3.5 mm. It should be noted that by limiting the lens surface structure and the corresponding exit pupil distance of the multiple coaxial lenses of the optical imaging lens group that are close to the curved surface image, it can be matched with the corresponding curved surface scanned image, so as to realize clear imaging from the curved surface image to the planar image.

[0074] In addition, it needs to be further explained that, please continue to refer toFigure 2b :

[0075] Entrance pupil: The entrance pupil is the effective aperture that limits the incident light beam. It is the image formed by the aperture stop on the front optical system and is the conjugate image of the aperture stop in the object space. The entrance pupil corresponds to the exit pupil.

[0076] Entrance pupil position: The entrance pupil position is the position point of the image formed by the aperture stop on the front optical system. The calculation of the entrance pupil position is to consider the center of the aperture stop as an object point and trace the light rays forward to the optical system to obtain the intersection coordinates with the point on the optical axis. Usually, the distance from the first lens surface is used as the entrance pupil distance.

[0077] Exit pupil: The image formed by the aperture stop of the optical system in the image space of the optical system is the exit pupil of the lens.

[0078] Exit pupil position: The exit pupil position is the position point of the image formed by the aperture stop on the rear optical system. The calculation of the exit pupil position is to consider the center of the aperture stop as an object point and trace the light rays backward to the optical system to obtain the intersection coordinates with the point on the optical axis. Usually, the distance from the last lens surface is used as the exit pupil distance.

[0079] Measurement of the exit pupil position: Set a point light source at the center of the entrance pupil position, and image it through the designed lens. The best imaging position of the point light source is the exit pupil position.

[0080] More specifically, as Figure 2b shown, from left to right, that is, from the first side to the second side, are the entrance pupil (entrance pupil position), the optical imaging lens group, and the exit pupil (exit pupil position) in sequence.

[0081] Example 1

[0082] Figure 3 is a schematic structural diagram of an optical imaging lens group provided by an embodiment of the present invention. The optical imaging lens group includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, and a fifth lens 15 that are coaxially arranged in sequence from the first side (that is, Figure 3 the side where the diaphragm 01 in Figure 3 is located) to the second side (that is,

[0083] the side where the scanning surface 02 in

[0084] In this embodiment, there is a gap between every two adjacent lenses among the first lens 11, the second lens 12, the third lens 13, the fourth lens 14, and the fifth lens 15. The first lens 11, the second lens 12, the third lens 13, the fourth lens 14, and the fifth lens 15 are five single non-bonded lenses.

[0085] The first side surface of the first lens 11 is convex, and the second side surface is concave.

[0086] The first side surface of the second lens 12 is convex, and the second side surface is concave.

[0087] The first side surface of the third lens 13 is convex near the optical axis, and the second side surface is concave.

[0088] The first side surface of the fourth lens 14 is convex, and the second side surface is convex near the optical axis.

[0089] The first side surface of the fifth lens 15 is convex, and the second side surface is concave near the optical axis.

[0090] In this embodiment, the focal lengths of the first lens 11 to the fifth lens 1 fifteenth lens 15 in the optical imaging lens group satisfy the following relational expressions:

[0091] f1 / f is 2.58, f2 / f is -0.41, f3 / f is 0.59, f4 / f is 0.93, and f5 / f is 8.98; where f1 is the focal length of the first lens 11, f2 is the focal length of the second lens 12, f3 is the focal length of the third lens 13, f4 is the focal length of the fourth lens 14, f5 is the focal length of the fifth lens 15, and f is the equivalent focal length of the optical imaging lens group.

[0092] The refractive indices and dispersion coefficients of the first lens 11 to the fifth lens 15 in the optical imaging lens group respectively satisfy the following conditions:

[0093] n1 is 1.59, n2 is 1.74, n3 is 1.62, n4 is 1.56, and n5 is 1.74. Among them, n1 to n5 respectively represent the refractive indices of the first lens 11 to the fifth lens 15; the Abbe number of the first lens is 43.2, the Abbe number of the second lens is 28.3, the Abbe number of the third lens is 60.1, the Abbe number of the fourth lens is 64, and the Abbe number of the fifth lens is 44.9.

[0094] In the optical imaging lens group provided in the first embodiment of the present invention; the overall equivalent focal length of the optical imaging lens group is 2.60 mm, the aperture value is 1.30, the half field angle is 10 degrees, the scanning radius is 2 mm, and the entrance pupil diameter is 2 mm. The preferred parameters of the curvature radius, thickness parameter, refractive index, and dispersion coefficient of each lens for imaging the scanning curved surface 02 are shown in Table 1:

[0095] Table 1 Structural parameters of the optical imaging lens group in the first embodiment

[0096] Surface Lens Serial Number Surface Shape Radius of Curvature Thickness / Spacing Material Refractive Index Dispersion Coefficient 0 Imaging Plane Plane Infinity Infinity 1 Aperture 01 Infinity 1 2 First Lens 11 Aspherical 3.21 1.85 1.59 43.2 3 Aspherical 13.74 1.04 4 Second Lens 12 Aspherical 21.18 1.02 1.74 28.3 5 Aspherical 0.73 0.13 6 Third Lens 13 Aspherical 0.90 1.09 1.62 60.1 7 Aspherical 8.75 0.10 8 Fourth Lens 14 Aspherical 3.57 1.17 1.56 64 9 Aspherical -1.91 0.10 10 Fifth Lens 15 Aspherical 0.78 0.71 1.74 44.9 11 Aspherical 0.50 0.50 12 Scanning Surface 02 Spherical 2

[0097] It should be noted that Table 1 shows the detailed structural data of the optical imaging lens group in the first embodiment. Among them, the units of the radius of curvature, thickness, and focal length are all millimeters, and the surfaces 0 - 12 sequentially represent the surfaces from the first side to the second side; the optical surface with an infinite radius of curvature in the imaging plane refers to a plane surface.

[0098] Furthermore, the aspherical conic coefficients of the surfaces corresponding to the first lens 11 to the fifth lens 15 are shown in Table 2 below:

[0099] Table 2 Aspherical conic coefficient data of different lens surfaces in the first embodiment

[0100] Surface K A4 A6 A8 2 -1.24E+01 5.51E-02 -1.18E-02 3.78E-03 3 1.85E+02 3.85E-02 2.50E-02 1.36E-02 4 3.82E+02 -1.24E-01 1.21E-01 -4.28E-02 5 -3.29E+00 -6.10E-02 7.07E-02 -3.33E-02 6 -3.29E+00 -8.25E-02 4.68E-02 -1.12E-02 7 1.70E+01 -1.19E-01 1.77E-02 2.42E-03 8 1.28E+00 5.44E-02 1.07E-03 1.34E-03 9 -1.10E+00 5.40E-02 1.19E-01 -4.80E-02 10 -5.99E-01 -2.84E-02 -5.33E-02 -8.63E-02 11 -6.76E-01 -1.28E-01 -3.14E+00 2.32E+00

[0101] Table 2 shows the aspherical coefficient data in the first embodiment, where k is the conic coefficient in the aspherical curve equation, and A4 to A8 represent the 4th to 8th order aspherical coefficients of each surface.

[0102] Furthermore, through testing, when using the above optical imaging lens group to project the image light corresponding to the scanning surface, its optical transfer function curve is as shown in Figure 4 shown, the field curvature distortion curve is as shown in Figure 5 shown, and the lateral chromatic aberration curve is as shown in Figure 6 shown; among them, the optical transfer function curve (Modulation Transfer Function, MTF) represents the comprehensive resolution level of an optical system, the field curvature distortion curve represents the F - Tan(theta) distortion magnitude value (percentage) under different field of view angles, and the lateral chromatic aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0103] From Figures 4 - 6 observation, it can be seen that the imaging resolution of the optical imaging lens group in the first embodiment is good within the full field of view, and the distortion and chromatic aberration of the optical system are small. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber scanner and all have good imaging effects.

[0104] Of course, in practical applications, the optical imaging lens group may also include a display element, a housing, etc. The display element can be arranged on the second side of the optical imaging lens group, and the optical imaging lens group can be installed in the housing, so as to image the curved surface image formed by scanning an image source (such as a fiber scanner) onto a plane to achieve clear imaging.

[0105] Embodiment 2

[0106] Figure 7 This is a schematic structural diagram of an optical imaging lens group provided by an embodiment of the present invention. The optical imaging lens group includes from the first side (that is, Figure 7 the side where the aperture stop 03 is located in Figure 7The first lens 31, the second lens 32, the third lens 33, the fourth lens 34, and the fifth lens 35 are arranged coaxially in sequence on the side where the scanning surface 04 in

[0107] In this embodiment, there is a gap between every two adjacent lenses among the first lens 31, the second lens 32, the third lens 33, the fourth lens 34, and the fifth lens 35. The first lens 31, the second lens 32, the third lens 33, the fourth lens 34, and the fifth lens 35 are five single non-bonded lenses.

[0108] The focal lengths of the first lens 31 to the fifth lens 35 from the first side to the second side are positive, negative, positive, positive, and positive in sequence.

[0109] The first side surface of the first lens 31 is a convex surface, and the second side surface is a concave surface.

[0110] Both the first side surface and the second side surface of the second lens 32 are concave surfaces.

[0111] The first side surface of the third lens 33 is a convex surface, and the second side surface is a concave surface.

[0112] The first side surface of the fourth lens 34 is a convex surface, and the second side surface is a convex surface near the optical axis.

[0113] The first side surface of the fifth lens 35 is a convex surface, and the second side surface is a concave surface near the optical axis.

[0114] In this embodiment, the focal lengths of the first lens 31 to the fifth lens 35 in the optical imaging lens group satisfy the following relational expressions:

[0115] f1 / f is 2.49, f2 / f is -0.65, f3 / f is 1.45, f4 / f is 0.91, and f5 / f is 10.53; where f1 is the focal length of the first lens 31, f2 is the focal length of the second lens 32, f3 is the focal length of the third lens 33, f4 is the focal length of the fourth lens 34, f5 is the focal length of the fifth lens 35, and f is the equivalent focal length of the optical imaging lens group.

[0116] The refractive indices and dispersion coefficients of the first lens 31 to the fifth lens 35 in the optical imaging lens group respectively satisfy the following conditions:

[0117] n1 is 1.59, n2 is 1.76, n3 is 1.62, n4 is 1.54, and n5 is 1.62. Among them, n1 to n5 respectively represent the refractive indices of the first lens 31 to the fifth lens 35; the Abbe number of the first lens is 61.4, the Abbe number of the second lens is 27.6, the Abbe number of the third lens is 60.3, the Abbe number of the fourth lens is 65.1, and the Abbe number of the fifth lens is 60.3.

[0118] In the optical imaging lens group provided in the second embodiment of the present invention, the overall equivalent focal length of the optical imaging lens group is 2.6 mm, the aperture value is 1.30, the half field of view angle is 10 degrees, the scanning radius is 2 mm, and the entrance pupil diameter is 2 mm. The preferred parameters of the curvature radius, thickness parameter, refractive index, and dispersion coefficient of each lens for imaging the scanning surface 04 are shown in Table 3:

[0119] Table 3 Structural parameters of the optical imaging lens group in the second embodiment

[0120]

[0121]

[0122] It should be noted that Table 3 shows the detailed structural data of the optical imaging lens group in the second embodiment. Among them, the units of the curvature radius, thickness, and focal length are all millimeters, and the surfaces 0-12 represent the surfaces from the first side to the second side in sequence; the optical surface with an infinite curvature radius in the imaging plane refers to a plane.

[0123] Furthermore, the aspherical conic coefficients of the surfaces corresponding to the first lens 31 to the fifth lens 35 are as shown in Table 4 below:

[0124] Table 4 Aspherical conic coefficient data of different lens surfaces in the second embodiment

[0125] Surface K A4 A6 A8 2 -1.82E+01 4.71E-02 -1.18E-02 3.78E-03 3 4.00E+02 3.38E-02 1.00E-02 1.25E-02 4 -1.89E+02 -1.31E-01 1.20E-01 -4.27E-02 5 -4.77E+00 -7.97E-02 6.13E-02 -3.43E-02 6 -3.01E+00 -8.28E-02 4.12E-02 -1.80E-02 7 3.56E+01 -1.19E-01 1.61E-02 2.42E-03 8 6.77E-01 5.28E-02 4.61E-04 2.26E-03 9 -1.32E+00 5.80E-02 1.21E-01 -4.34E-02 10 -4.37E-01 -4.33E-02 -1.86E-02 -1.18E-01 11 -9.69E-01 6.42E-01 -2.14E+00 1.16E+00

[0126] Table 4 shows the aspherical coefficient data in the second embodiment. Among them, k is the conic coefficient in the aspherical curve equation, and A4 to A8 represent the 4th to 8th order aspherical coefficients of each surface.

[0127] Furthermore, after testing, when using the above optical imaging lens group to project the image light corresponding to the scanning surface, its optical transfer function curve is as shown in Figure 8 shown, the field curvature distortion curve is as shown in Figure 9 shown, and the lateral chromatic aberration curve is as shown in Figure 10 shown; among them, the optical transfer function curve (Modulation Transfer Function, MTF) represents the comprehensive resolution level of an optical system, the field curvature distortion curve represents the F-Tan(theta) distortion magnitude value (percentage) under different field of view angles, and the lateral chromatic aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0128] From Figures 8 - 10 observation, it can be seen that the optical imaging lens group in the second embodiment has good imaging resolution within the full field of view, small optical system distortion and chromatic aberration. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber scanner and all have good imaging effects.

[0129] Of course, in practical applications, the optical imaging lens group may further include a display element, a housing, etc. The display element

[0130] can be arranged on the second side of the optical imaging lens group. The optical imaging lens group can be installed in the housing, so that a curved surface image formed by scanning an image source (such as an optical fiber scanner) can be imaged on a plane to achieve clear imaging.

[0131] Embodiment III

[0132] Figure 11 FIG. is a schematic structural diagram of an optical imaging lens group provided by an embodiment of the present invention. The optical imaging lens group includes a first lens 51, a second lens 52, a third lens 53, a fourth lens 54, and a fifth lens 55 that are sequentially arranged on the common optical axis from the first side (i.e., the side where the aperture stop 05 is located in Figure 11 to the second side (i.e., the side where the scanning curved surface 06 is located in Figure 11 ).

[0133] In this embodiment, there is a gap between every two adjacent lenses among the first lens 51, the second lens 52, the third lens 53, the fourth lens 54, and the fifth lens 55. The first lens 51, the second lens 52, the third lens 53, the fourth lens 54, and the fifth lens 55 are five single non-bonded lenses.

[0134] The focal lengths of the first lens 51 to the fifth lens 55 from the first side to the second side are positive, negative, positive, positive, and positive in sequence.

[0135] Both the first side surface and the second side surface of the first lens 51 are convex surfaces.

[0136] Both the first side surface and the second side surface of the second lens 52 are concave surfaces.

[0137] The first side surface of the third lens 53 is a convex surface, and the second side surface is a concave surface near the optical axis.

[0138] The first side surface of the fourth lens 54 is a convex surface, and the second side surface is a convex surface near the optical axis.

[0139] The first side surface of the fifth lens 55 is a convex surface, and the second side surface is a concave surface near the optical axis.

[0140] In this embodiment, the focal lengths of the first lens 51 to the fifth lens 55 in the optical imaging lens group satisfy the following relationship:

[0141] f1 / f is 2.69, f2 / f is -0.96, f3 / f is 3.14, f4 / f is 0.97, and f5 / f is 19.23; where f1 is the focal length of the first lens 51, f2 is the focal length of the second lens 52, f3 is the focal length of the third lens 53, f4 is the focal length of the fourth lens 54, f5 is the focal length of the fifth lens 55, and f is the equivalent focal length of the optical imaging lens group.

[0142] In the optical imaging lens group, the refractive indices and dispersion coefficients of the first lens 51 to the fifth lens 55 respectively satisfy the following conditions:

[0143] n1 is 1.49, n2 is 1.76, n3 is 1.60, n4 is 1.49, and n5 is 1.62. Where n1 to n5 respectively represent the refractive indices of the first lens 51 to the fifth lens 55; the Abbe number of the first lens is 70.4, the Abbe number of the second lens is 27.6, the Abbe number of the third lens is 61.3, the Abbe number of the fourth lens is 70.4, and the Abbe number of the fifth lens is 60.3.

[0144] In the optical imaging lens group provided in the third embodiment of the present invention, the equivalent focal length of the overall optical imaging lens group is 2.6 mm, the aperture value is 1.30, the half field angle is 10 degrees, the scanning radius is 2 mm, and the entrance pupil diameter is 2 mm. The preferred parameters of the curvature radius, thickness parameter, refractive index, and dispersion coefficient of each lens for imaging the scanning curved surface 06 are shown in Table 5:

[0145] Table 5 Structural parameters of the optical imaging lens group in the third embodiment

[0146] Surface Lens Serial Number Surface Shape Radius of Curvature Thickness / Spacing Material Refractive Index Dispersion Coefficient 0 Imaging Plane Plane Infinity Infinity 1 Aperture 05 Infinity 1 2 First Lens 51 Aspherical 14.48 2.00 1.49 70.4 3 Aspherical -4.28 2.32 4 Second Lens 52 Aspherical -5.55 0.60 1.76 27.6 5 Aspherical 3.07 0.10 6 Third Lens 53 Aspherical 3.21 0.96 1.6 61.3 7 Aspherical 8.10 0.10 8 Fourth Lens 54 Aspherical 3.09 1.17 1.49 70.4 9 Aspherical -1.82 0.10 10 Fifth Lens 55 Aspherical 0.75 0.81 1.62 60.3 11 Aspherical 0.44 0.50 12 Scanning Surface 06 Spherical 2

[0147] It should be noted that Table 5 shows the detailed structural data of the optical imaging lens group in the third embodiment. Among them, the units of the curvature radius, thickness, and focal length are all millimeters, and the surfaces 0 - 12 sequentially represent the surfaces from the first side to the second side; the optical surface with an infinite curvature radius in the imaging plane refers to a plane.

[0148] Furthermore, the aspherical conic coefficients of the surfaces corresponding to the first lens 51 to the fifth lens 55 are as shown in Table 6 below:

[0149] Table 6 Aspherical conic coefficient data of different lens surfaces in the third embodiment

[0150]

[0151]

[0152] Table 6 shows the aspherical coefficient data in the third embodiment. Among them, k is the conic coefficient in the aspherical curve equation, and A4 to A8 represent the 4th to 8th order aspherical coefficients of each surface.

[0153] Further, through testing, when the image light corresponding to the projection scanning surface is projected by the above optical imaging lens group, the curve graph of its optical transfer function is as shown in Figure 12 shown, the curve graph of field curvature distortion is as shown in Figure 13 shown, and the curve graph of lateral chromatic aberration is as shown in Figure 14 shown; among them, the curve graph of the optical transfer function (Modulation Transfer Function, MTF) represents the comprehensive resolution level of an optical system, the curve graph of field curvature distortion represents the magnitude value (percentage) of F-Tan(theta) distortion under different field angles of view, and the curve graph of lateral chromatic aberration represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0154] From Figures 12 - 14 observation, it can be seen that the imaging resolution within the full field of view of the optical imaging lens group in the third embodiment is good, and the distortion and chromatic aberration of the optical system are small. Therefore, the optical imaging lens group can clearly image the scanning curved surface image of the fiber optic scanner, and all have good imaging effects.

[0155] Of course, in practical applications, the optical imaging lens group may further include a display element, a housing, etc. The display element can be arranged on the second side of the optical imaging lens group, and the optical imaging lens group can be installed in the housing, that is, the curved surface image formed by scanning an image source (such as a fiber optic scanner) can be imaged on a plane to achieve clear imaging.

[0156] Embodiment Four

[0157] Figure 15 This is a schematic structural diagram of an optical imaging lens group provided by an embodiment of the present invention. The optical imaging lens group includes a first lens 71, a second lens 72, a third lens 73, a fourth lens 74, a fifth lens 75, and a sixth lens 76 that are coaxially arranged in sequence from the first side (that is, the side where the aperture stop 07 is located in Figure 15 ) to the second side (that is, the side where the scanning curved surface 08 is located in Figure 15 ). It should be noted that the first lens 71 provided by the embodiment of the present invention is equivalent to an additional lens, and the positive and negative of the focal lengths of the second lens 72, the third lens 73, the fourth lens 74, the fifth lens 75, and the sixth lens 76 correspond to the positive and negative of the focal lengths of the five lenses mentioned in the foregoing embodiment. The "first" and "second" in the embodiment do not distinguish the importance or order of the lenses, but only distinguish different components by naming.

[0158] In this embodiment, there is a gap between every two adjacent lenses among the first lens 71, the second lens 72, the third lens 73, the fourth lens 74, the fifth lens 75, and the sixth lens 76. The first lens 71, the second lens 72, the third lens 73, the fourth lens 74, the fifth lens 75, and the sixth lens 76 are six single non-bonded lenses.

[0159] The focal lengths of the first lens 71 to the sixth lens 76 from the first side to the second side are positive, positive, negative, positive, positive, and positive in sequence.

[0160] The first-side surface of the first lens 71 is concave, and the second-side surface is convex.

[0161] The first-side surface of the second lens 72 is convex, and the second-side surface is convex near the optical axis.

[0162] Both the first-side surface and the second-side surface of the third lens 73 are concave.

[0163] The first-side surface of the fourth lens 74 is convex, and the second-side surface is concave.

[0164] The first-side surface of the fifth lens 75 is convex, and the second-side surface is convex near the optical axis.

[0165] The first-side surface of the sixth lens 76 is convex, and the second-side surface is concave near the optical axis.

[0166] In this embodiment, the focal lengths of the first lens 71 to the sixth lens 76 in the optical imaging lens group satisfy the following relational expressions:

[0167] f1 / f is 7.48, f2 / f is 2.96, f3 / f is -0.42, f4 / f is 0.7, f5 / f is 1.14, and f6 / f is 2.32; where f1 is the focal length of the first lens 71, f2 is the focal length of the second lens 72, f3 is the focal length of the third lens 73, f4 is the focal length of the fourth lens 74, f5 is the focal length of the fifth lens 75, f6 is the focal length of the sixth lens 76, and f is the equivalent focal length of the optical imaging lens group.

[0168] The refractive indices and dispersion coefficients of the first lens 71 to the sixth lens 76 in the optical imaging lens group respectively satisfy the following conditions:

[0169] n1 is 1.75, n2 is 1.56, n3 is 1.75, n4 is 1.63, n5 is 1.54, n6 is 1.74. Among them, n1 to n6 respectively represent the refractive indices of the first lens 71 to the sixth lens 76; the Abbe number of the first lens is 31.5, the Abbe number of the second lens is 64, the Abbe number of the third lens is 27.9, the Abbe number of the fourth lens is 58.9, the Abbe number of the fifth lens is 65.4, and the Abbe number of the sixth lens is 45.3.

[0170] In the optical imaging lens group provided in the fourth embodiment of the present invention, the overall equivalent focal length of the optical imaging lens group is 2.6 mm, the aperture value is 1.30, the half field of view angle is 10 degrees, the scanning radius is 2 mm, and the entrance pupil diameter is 2 mm. The preferred parameters of the curvature radius, thickness parameter, refractive index, and dispersion coefficient of each lens for imaging the scanning curved surface 08 are shown in Table 7:

[0171] Table 7 Structural parameters of the optical imaging lens group in the fourth embodiment

[0172] Surface Lens Serial Number Surface Shape Radius of Curvature Thickness / Spacing Material Refractive Index Dispersion Coefficient 0 Imaging Plane Plane Infinity Infinity 1 Aperture 07 Infinity 1 2 First Lens 71 Spherical -5.30 0.76 1.75 31.5 3 Spherical -4.14 0.10 4 Second Lens 72 Aspherical 4.91 1.79 1.56 64 5 Aspherical -31.57 1.31 6 Third Lens 73 Aspherical -5.90 0.97 1.75 27.9 7 Aspherical 1.02 0.12 8 Fourth Lens 74 Aspherical 1.05 1.04 1.63 58.9 9 Aspherical 7.76 0.10 10 Fifth Lens 75 Aspherical 3.39 1.20 1.54 65.4 11 Aspherical -2.71 0.10 12 Sixth Lens 76 Aspherical 0.70 0.68 1.74 45.3 13 Aspherical 0.49 0.50 14 Scanning Surface 08 Spherical 2

[0173] It should be noted that Table 7 is the detailed structural data of the optical imaging lens group in the fourth embodiment. Among them, the units of the curvature radius, thickness, and focal length are all millimeters, and the surfaces 0-14 represent the surfaces from the first side to the second side in sequence; the optical surface with an infinite curvature radius in the imaging plane refers to a plane.

[0174] Furthermore, the aspherical conic coefficients of the surfaces corresponding to the first lens 71 to the sixth lens 76 are as shown in Table 8 below:

[0175] Table 8 Aspherical conic coefficient data of different lens surfaces in the fourth embodiment

[0176] Surface K A4 A6 A8 4 -3.40E+01 3.28E-02 -1.30E-02 3.78E-03 5 2.39E+02 1.51E-02 5.97E-03 3.98E-03 6 -8.88E+01 -1.06E-01 1.08E-01 -4.83E-02 7 -4.08E+00 -7.40E-02 7.13E-02 -4.22E-02 8 -3.20E+00 -8.04E-02 4.04E-02 -9.29E-03 9 3.98E+01 -1.12E-01 1.54E-02 2.42E-03 10 -3.21E-01 4.91E-02 -3.50E-03 -4.22E-04 11 1.15E+00 4.62E-02 1.06E-01 -5.43E-02 12 -4.40E-01 -3.41E-02 -9.35E-03 -1.28E-01 13 -8.18E-01 7.51E-01 -2.18E+00 2.99E+00

[0177] Table 8 is the aspherical coefficient data in the fourth embodiment. Among them, k is the conic coefficient in the aspherical curve equation, and A4 to A8 represent the 4th to 8th order aspherical coefficients of each surface.

[0178] Furthermore, after testing, when using the above optical imaging lens group to project the image light corresponding to the scanning surface, its optical transfer function curve is as shown in Figure 16 shown, the field curvature distortion curve is as shown in Figure 17 shown, and the lateral chromatic aberration curve is as shown in Figure 18 shown; among them, the optical transfer function curve (Modulation Transfer Function, MTF) represents the comprehensive resolution level of an optical system, the field curvature distortion curve represents the F-Tan(theta) distortion magnitude value (percentage) under different field of view angles, and the lateral chromatic aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0179] From Figures 16 - 18 observation, it can be seen that the imaging resolution of the optical imaging lens group in the fourth embodiment is good within the full field of view, and the distortion and chromatic aberration of the optical system are small. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber scanner, and all have good imaging effects.

[0180] Of course, in practical applications, the optical imaging lens group may further include a display element, a housing, etc. The display element may be disposed on the second side of the optical imaging lens group. The optical imaging lens group may be installed in the housing, that is, the curved surface image formed by scanning an image source (such as an optical fiber scanner) can be imaged on a plane to achieve clear imaging.

[0181] Scanning Display Device

[0182] The foregoing optical imaging lens group can cooperate with an optical fiber scanner (or a corresponding optical fiber scanning module) to form the scanning display device in the embodiments of the present application (such as Figure 1a , 1b shown, the optical imaging lens group is disposed on the light output path of the optical fiber scanner), wherein the first side of the optical imaging lens group faces the light output direction of the optical fiber scanner scanning. The preferred method is that the optical imaging lens group is coaxial with the central optical axis of the optical fiber scanner. Of course, the structure and general principle of the optical fiber scanner can be referred to the foregoing Figure 1a , 1b corresponding content, and will not be elaborated here too much.

[0183] Near-Eye Display Device

[0184] In the present application, the scanning display device can be further applied to a near-eye display device, and can cooperate with a near-eye display module to form the near-eye display device in the embodiments of the present application, and be used as a head-mounted AR device (such as: AR glasses). The scanning display device is disposed in the near-eye display module.

[0185] Among them, the near-eye display module may include: a light source, a processing and control circuit, a wearable frame structure, a waveguide, etc. The image light beam output by the light source enters the scanning display device, and is scanned and output to the optical display lens group by the optical fiber scanner therein. The scanning curved surface of the optical fiber scanner (the scanning curved surface 02 in Figure 3 and the corresponding Figure 2a scanning curved surface 230) is converted into an imaging plane (the imaging plane 240 in Figure 2a ) after passing through the optical display lens group. This imaging plane is coupled into the waveguide as the entrance pupil plane of the waveguide, and then is extended and imaged by the waveguide and coupled out to enter the human eye.

[0186] As another possible implementation manner, the scanning display device can further cooperate with the near-eye display module to form the near-eye display device in the embodiments of the present application, and be used as a head-mounted VR device (such as: VR helmet / glasses). The scanning display device is disposed in the near-eye display module.

[0187] In the embodiments of the present application, by reasonably optimizing the focal lengths of five coaxial lenses of the optical imaging lens group, the optical power of the system can be reasonably dispersed, the aberration generated by the lenses can be reduced, and the purpose of correcting various aberrations can be achieved. On the basis of increasing the field of view angle, clear imaging of the image-side surface can be realized. By limiting and optimizing the refractive index, dispersion coefficient, and surface shape structure of the five coaxial lenses, the imaging quality and the field of view angle are further improved. By limiting and optimizing the design of the five coaxial lenses to an aspherical surface shape structure, on the basis of further improving the imaging quality, the overall structure of the optical imaging lens group is also more compact, meeting the production requirements of miniaturization of lens products.

[0188] The above are only the preferred specific embodiments of the present application. Each embodiment is only used to illustrate the technical solution of the present application and does not limit the present application. Any technical solution that can be obtained by those skilled in the art through logical analysis, reasoning, or effective experiments according to the concept of the present application should be within the scope of the present application.

[0189] The embodiments in the present application are all described in a progressive manner. The same or similar parts between the embodiments can be referred to each other, and the differences between each embodiment and other embodiments are emphasized.

[0190] In various embodiments of the present disclosure, the expressions "first", "second", "the first", or "the second" used may modify various components without being related to the order and / or importance, but these expressions do not limit the corresponding components. The above expressions are only configured for the purpose of distinguishing an element from other elements. For example, the first lens and the second lens represent different lenses, although both are lenses.

Claims

1. An optical imaging lens group, characterized in that, The optical imaging lens group at least includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens that are coaxially arranged in sequence from the first side to the second side. The focal lengths of the first lens to the fifth lens are positive, negative, positive, positive, and positive respectively; the various lenses satisfy the following relationships: 2.49 ≤ f1 / f ≤ 2.69, -0.96 ≤ f2 / f ≤ -0.41, 0.59 ≤ f3 / f ≤ 3.14, 0.91 ≤ f4 / f ≤ 0.97, and 8.98 ≤ f5 / f ≤ 19.23; where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, and f is the focal length of the optical imaging lens group; the exit pupil distance of the optical imaging lens group is 1.5 - 6.0 mm.

2. The optical imaging lens group according to claim 1, wherein Wherein, The second side surface of the fifth lens is concave near the optical axis.

3. The optical imaging lens group according to claim 2, wherein, The various lenses also satisfy the following relationships: 1.49 ≤ n1 ≤ 1.59, 1.74 ≤ n2 ≤ 1.76, 1.6 ≤ n3 ≤ 1.62, 1.49 ≤ n4 ≤ 1.56, 1.62 ≤ n5 ≤ 1.74; where n1 is the refractive index of the first lens, n2 is the refractive index of the second lens, n3 is the refractive index of the third lens, n4 is the refractive index of the fourth lens, and n5 is the refractive index of the fifth lens; The dispersion coefficients of the various lenses satisfy: 43.2 ≤ v1 ≤ 70.4, 27.6 ≤ v2 ≤ 28.3, 60.1 ≤ v3 ≤ 60.3, 64 ≤ v4 ≤ 70.4, 44.9 ≤ v5 ≤ 60.3; where v1 is the Abbe number of the first lens, v2 is the Abbe number of the second lens, v3 is the Abbe number of the third lens, v4 is the Abbe number of the fourth lens, and v5 is the Abbe number of the fifth lens.

4. The optical imaging lens group according to claim 3, wherein The n1 is 1.49 or 1.59, the n2 is 1.74 or 1.76, the n3 is 1.60 or 1.62, the n4 is 1.49 or 1.54 or 1.56, and the n5 is 1.62 or 1.74; The dispersion coefficients of the various lenses satisfy: the Abbe number of the first lens is 43.2 or 61.4 or 70.4, the Abbe number of the second lens is 27.6 or 28.3, the Abbe number of the third lens is 60.1 or 60.3, the Abbe number of the fourth lens is 64 or 65.1 or 70.4, and the Abbe number of the fifth lens is 44.9 or 60.

3.

5. The optical imaging lens group according to claim 2, wherein The first side surface of the fifth lens is convex; the first side surface of the fourth lens is convex, and the second side surface of the fourth lens is convex near the optical axis.

6. The optical imaging lens group according to any one of claims 1 to 5, characterized in that The first side surface of the first lens is convex, and the second side surface of the first lens is concave or convex.

7. The optical imaging lens group according to claim 6, wherein, The first side surface of the second lens is concave or convex, and the second side surface of the second lens is concave; the first side surface of the third lens is convex near the optical axis, and the second side surface of the third lens is concave; The first side surfaces and the second side surfaces of the first lens to the fifth lens are all aspherical surface structures; The second side of the optical imaging lens group corresponds to a curved surface image, and the first side of the optical imaging lens group corresponds to a planar image.

8. A scanning display device, characterized in that, Comprising an optical fiber scanner and the optical imaging lens group according to any one of the preceding claims 1 to 7, the optical fiber scanner is configured to scan and emit light of an image to be displayed, and the optical imaging lens group is configured to magnify and project an image of a scanning plane corresponding to the light emitted by the optical fiber scanner; Wherein, the optical fiber scanner includes an actuator and an optical fiber fixed to the actuator, and a part of the optical fiber exceeding the actuator forms an optical fiber cantilever, and the optical fiber cantilever performs two-dimensional scanning under the drive of the actuator.

9. A near-eye display device, characterized in that, The near-eye display device is used as a head-mounted augmented reality device, and at least includes a near-eye display module and the scanning display device according to claim 8, and the scanning display device is disposed in the near-eye display module.

10. A near-eye display device, characterized in that, The near-eye display device is used as a head-mounted virtual reality device, and at least includes a near-eye display module and the scanning display device according to claim 8, and the scanning display device is disposed in the near-eye display module.

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