Optical imaging lens, scanning display device and near-eye display device

Abstract

The embodiment of the application discloses an optical imaging lens, a scanning display device and a near-eye display device, and relates to the technical field of scanning display. The optical imaging lens can reasonably disperse the optical power of the system, slow down the aberration generated by the lens, achieve the purpose of correcting various aberrations, and realize clear imaging of the image surface on the basis of improving the field of view by reasonably optimizing the focal lengths of five coaxial lenses of the optical imaging lens. The field of view and the imaging quality are further improved by limiting and optimizing the refractive index, the dispersion coefficient and the surface structure of the five coaxial lenses. The overall structure of the optical imaging lens can be more compact on the basis of further improving the imaging quality by limiting and optimizing the five coaxial lenses to be aspherical surface structures, so that the production demand of miniaturization of the lens product is met.

Description

TECHNICAL FIELD

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

[0002] Scanning display imaging as a new display technology 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 high processing difficulty, high mass production cost, poor imaging quality, small field of view angle and the inability to be miniaturized, which limits the application of scanning display imaging technology in the market, especially when it is applied to the near-eye display scenario. The imaging effect and the field of view angle limit the performance requirements of high resolution in the near-eye display, thereby hindering the development of the near-eye display to the consumer market. SUMMARY

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

[0005] The present application provides an optical imaging lens, which comprises at least a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged in sequence from a first side to a second side and sharing an optical axis, wherein the focal lengths of the first lens to the fifth lens are negative, positive, negative, positive and negative respectively.

[0006] Optionally, the various lenses satisfy the following relationship: 0.39≤|f3 / f|≤0.54 and 1.43≤|f5 / f|≤2.88, wherein f3 is the focal length of the third lens, f5 is the focal length of the fifth lens, and f is the focal length of the optical imaging lens.

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

[0008] Optionally, the various lenses satisfy the following relationship: 1.54≤|f1 / f|≤21.59, 0.68≤f2 / f≤0.97 and 0.55≤f4 / f≤0.57, wherein f1 is the focal length of the first lens, f2 is the focal length of the second lens, f4 is the focal length of the fourth lens, and f is the focal length of the optical imaging lens.

[0009] The various lenses satisfy the following relationship: 1.54≤n1≤1.67, 1.56≤n2≤1.75, 1.63≤n3≤1.76, 1.49≤n4≤1.57, 1.54≤n5≤1.67; wherein 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 the various lenses satisfy: 46.3≤v1≤55.7, 23.2≤v2≤62.8, 23.2≤v3≤29.3, 62.4≤v4≤70.4, 52.1≤v5≤60.3; wherein 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] Optionally, n1 is 1.63 or 1.66 or 1.69 or 1.73, n2 is 1.56 or 1.57 or 1.58, n3 is 1.52 or 1.64 or 1.76, n4 is 1.49 or 1.52 or 1.57, and n5 is 1.62 or 1.64 or 1.74 or 1.75.

[0012] The dispersion coefficients of the various lenses satisfy: the Abbe number of the first lens is 35.8 or 39.8 or 46.3 or 53.1, the Abbe number of the second lens is 45 or 48.4 or 59.8 or 61.3, the Abbe number of the third lens is 22.4 or 27.6 or 56.2, the Abbe number of the fourth lens is 63.2 or 66.9 or 70.4, and the Abbe number of the fifth lens is 23.1 or 29.7 or 43 or 60.3.

[0013] Optionally, the first side surface of the fifth lens is convex, the first side surface of the fourth lens is concave or convex, and the second side surface of the fourth lens is convex.

[0014] Optionally, the first side surface of the third lens is concave or convex at the near optical axis, and the second side surface of the third lens is concave.

[0015] Optionally, the first side surface of the first lens is convex, and the second side surface of the first lens is concave; the first side surface of the second lens is convex, and the second side surface of the second lens is convex or concave.

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

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

[0018] The scanning display device also includes an optical fiber scanner configured to scan and emit light of an image to be displayed, and the optical imaging lens configured to magnify and project a scanning surface corresponding to the light emitted by the optical fiber scanner.

[0019] The optical fiber scanner includes an actuator and an optical fiber fixed to the actuator, and a portion of the optical fiber beyond the actuator forms an optical fiber cantilever, which is driven by the actuator to perform two-dimensional scanning.

[0020] The near-eye display device is used as a head-mounted augmented reality device and includes at least a near-eye display module and the scanning display device.

[0021] The near-eye display device is used as a head-mounted virtual reality device and includes at least a near-eye display module and the scanning display device.

[0022] The technical solutions in the embodiments of the present application can achieve the following technical effects:

[0023] In the embodiments of the present application, the focal lengths of the five coaxial lenses of the optical imaging lens are reasonably optimized to reasonably disperse the optical power of the system, slow down the aberration generated by the lens, achieve the purpose of correcting various aberrations, and clearly image the curved surface on the image side on the basis of improving the field of view. At the same time, the optical imaging lens has a compact overall structure due to the reasonable number of lens combinations, which meets the production needs of miniaturized lens products.

[0024] Further, the refractive index, dispersion coefficient, and surface structure of the five coaxial lenses are limited and optimized to further improve the field of view and imaging quality.

[0025] Other features and advantages of the present application will be described in the following description, and some will become apparent from the description, or will be understood from the practice of the present application. The purpose and other advantages of the present application can be achieved and obtained by the structures and / or processes specifically pointed out in the specification, claims, and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0026] Other features, objects, and advantages of the application will become more apparent from the following detailed description when read in conjunction with the accompanying drawings:

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

[0028] Figure 2a is a schematic diagram of scanning output of a fiber scanner provided by embodiments of the application;

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

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

[0031] Figure 4 is an MTF curve diagram of the optical imaging lens group in Embodiment One of the application;

[0032] Figure 5 is a field curvature distortion curve diagram of the optical imaging lens group in Embodiment One of the application;

[0033] Figure 6 is a sagittal chromatic aberration diagram of the optical imaging lens group in Embodiment One of the application.

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

[0035] Figure 8 is an MTF curve diagram of the optical imaging lens group in Embodiment Two of the application;

[0036] Figure 9 is a field curvature distortion curve diagram of the optical imaging lens group in Embodiment Two of the application;

[0037] Figure 10 is a sagittal chromatic aberration diagram of the optical imaging lens group in Embodiment Two of the application.

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

[0039] Figure 12 is an MTF curve diagram of the optical imaging lens group in Embodiment Three of the application;

[0040] Figure 13 is a field curvature distortion curve diagram of the optical imaging lens group in Embodiment Three of the application;

[0041] Figure 14is an axial chromatic aberration diagram of the optical imaging lens set in Embodiment Three of the present application;

[0042] Figure 15 is a structural schematic diagram of an optical imaging lens set provided in Embodiment Four of the present application;

[0043] Figure 16 is an MTF curve diagram of the optical imaging lens set in Embodiment Four of the present application;

[0044] Figure 17 is a field curvature distortion curve diagram of the optical imaging lens set in Embodiment Four of the present application;

[0045] Figure 18 is an axial chromatic aberration diagram of the optical imaging lens set in Embodiment Four of the present application;

[0046] Figure 19 is a structural schematic diagram of an optical imaging lens set provided in Embodiment Five of the present application;

[0047] Figure 20 is an MTF curve diagram of the optical imaging lens set in Embodiment Five of the present application;

[0048] Figure 21 is a field curvature distortion curve diagram of the optical imaging lens set in Embodiment Five of the present application;

[0049] Figure 22 is an axial chromatic aberration diagram of the optical imaging lens set in Embodiment Five of the present application.

[0050] Icon: 100-processor; 110-laser group; 120-fiber scanning module; 130-transmission fiber; 140-light source modulation circuit; 150-scanning driving circuit; 160-beam combining unit; 121-scanning actuator; 121a-slow axis; 121b-fast axis; 122-fiber cantilever; 123-lens group; 124-scanner package shell; 125-fixing piece; 230-scanning curved surface; 240-imaging plane; 11-first lens; 12-second lens; 13-third lens; 14-fourth lens; 15-fifth lens; 16-sixth lens; 01-diaphragm; 02-scanning curved surface; 31-first lens; 32-second lens; 33-third lens; 34-fourth lens; 35-fifth lens; 36-sixth lens; 03-diaphragm; 04-scanning curved surface; 51-first lens; 52-second lens; 53-third lens; 54-fourth lens; 55-fifth lens; 05-diaphragm; 06-scanning curved surface; 71-first lens; 72-second lens; 73-third lens; 74-fourth lens; 75-fifth lens; 76-sixth lens; 07-diaphragm; 08-scanning curved surface; 91-first lens; 92-second lens; 93-third lens; 94-fourth lens; 95-fifth lens; 09-diaphragm; 10-scanning curved surface. Detailed Implementation

[0051] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0052] Illustrative scanning display system

[0053] Current scanning display imaging can be achieved using either a Digital Micromirror Device (DMD) or a Fiber Scanning Display (FSD) device. The FSD approach, as a novel scanning display imaging method, uses a fiber optic scanner to achieve image scanning output. To enable those skilled in the art to clearly understand the present application, a brief explanation of the principles and corresponding system of fiber optic scanning imaging is provided below.

[0054] like Figure 1a The image shown is an illustrative scanning display system according to this application, which mainly includes:

[0055] The system includes a processor 100, a laser assembly 110, a fiber optic scanning module 120, a transmission fiber optic cable 130, a light source modulation circuit 140, a scanning drive circuit 150, and a beam combining unit 160.

[0056] The processor 100 can be a graphics processing unit (GPU), a central processing unit (CPU), or other chips or circuits with control and image processing functions, without being specifically limited here.

[0057] When the system is in operation, the processor 100 controls the light source modulation circuit 140 to modulate the laser group 110 according to the image data to be displayed. The laser group 110 contains multiple monochromatic lasers, each emitting a beam of a different color. As shown in Figure 1, the laser group can specifically use red (R), green (G), and blue (B) lasers. The beams emitted by each laser 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.

[0058] The processor 100 can also control the scanning drive circuit 150 to drive the fiber scanner in the fiber scanning module 120 to perform scanning, thereby scanning and outputting the beam transmitted in the transmission fiber 130.

[0059] A beam of light output from a fiber optic scanner acts on a specific pixel on the surface of a medium, forming a light spot at that pixel, thus achieving scanning of that pixel location. Driven by the fiber optic scanner, the output end of the transmission fiber 130 sweeps along a specific scanning trajectory, causing the beam to move to the corresponding pixel location. During the actual scanning process, the beam output from the transmission fiber 130 forms a light spot with corresponding image information (such as color, grayscale, or brightness) at each pixel location. Within one frame, the beam traverses each pixel location at a sufficiently high speed to complete the scanning of one frame of the image. Due to the "visual persistence" characteristic of human vision, the human eye cannot perceive the movement of the beam at each pixel location, but instead sees a complete image frame.

[0060] Continue to refer to Figure 1b The specific structure of the fiber optic scanning module 120 includes: a scanning actuator 121, a fiber optic cantilever 122, a mirror assembly 123, a scanner housing 124, and a fixing member 125. The scanning actuator 121 is fixed to the scanner housing 124 by the fixing member 125. The transmission fiber 130 extends from the front end of the scanning actuator 121 to form the fiber optic cantilever 122 (also called the scanning fiber). During operation, driven by the scanning drive signal, the slow axis 121a (also called the first actuation part) of the scanning actuator 121 moves along the vertical direction (this vertical direction is parallel to the...). Figure 1a , 1b The Y-axis in the reference coordinate system (in this application, the vertical direction can also be referred to as the first direction) vibrates, and its fast axis 121b (also referred to as the second actuator) vibrates along the horizontal direction (this horizontal direction is parallel to the reference coordinate system). Figure 1a , 1b The X-axis in the reference coordinate system (in this application, this horizontal direction can also be referred to as the second direction) vibrates, driven by the scanning actuator 121. The front end of the fiber optic cantilever 122 performs a two-dimensional sweep along a preset trajectory and emits a light beam. The emitted light beam can then pass through the mirror assembly 123 to achieve scanning imaging. Generally, the structure composed of the scanning actuator 121 and the fiber optic cantilever 122 can be called a fiber optic scanner.

[0061] like Figure 2a As shown in this embodiment, the motion trajectory of the optical fiber output end forms a scanning surface 230 through the movement of the fast and slow axes. After passing through the corresponding lens group 123, it is converted into an imaging plane 240. When applied to near-eye display devices such as augmented reality (AR) devices, the imaging plane 240 is coupled into the waveguide as the entrance pupil of the waveguide to form an image for human viewing.

[0062] To facilitate description and enable those skilled in the art to easily understand the solution of this application, it should be noted that the optical imaging lens assembly in this application (such as...) Figure 2aThe optical imaging lens group 123 shown in the middle as an eyepiece can convert the scanning curved surface 230 into an imaging plane 240 (in actual application, the transmission direction of light is from the scanning curved surface 230 to the imaging plane 240) through the action of the optical imaging lens group, so that the side corresponding to the imaging plane 240 of the optical imaging lens group is referred to as the first side, and the side corresponding to the scanning curved surface 230 of the optical imaging lens group is referred to as the second side. In the subsequent content, the embodiment scheme of the optical imaging lens group is described by taking the "first side" and "second side" as references. Moreover, in the subsequent embodiments, the description such as the "first side surface of the Xth lens" refers to the surface of the Xth lens facing the first side.

[0063] It needs to be further explained that in the projection field, the image corresponding to the first side is a planar image, and the corresponding planar image carrier can be, for example, a projection screen, a curtain or a wall surface, etc. The image corresponding to the second side is a curved surface image, that is, a scanning surface in an arc shape scanned by a fiber scanner or emitted by other image sources. In the use scenario in the camera field, the optical path is opposite to that in the projection field. The first side corresponds to the object side that generally collects image information, and the second side corresponds to the image side that generally collects the image.

[0064] Optical imaging lens

[0065] The optical imaging lens group in the embodiments of the present application at least includes: a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged in sequence from the first side to the second side and coaxially. It needs to be explained that the focal lengths of the first lens to the fifth lens in the embodiments of the present application are negative, positive, negative, positive and negative respectively. It needs to be explained that through reasonable optimization of the positive and negative of the focal lengths of the five coaxial lenses, the optical power of the system can be reasonably dispersed, the aberration generated by the lens can be slowed down, the purpose of correcting various aberrations can be achieved, and clear imaging of the curved surface on the image side can be realized on the basis of improving the field of view.

[0066] Further specifically preferably, the various lenses satisfy the following relationship: 1.54≤|f1 / f|≤21.59, 0.68≤f2 / f≤0.97, 0.39≤|f3 / f|≤0.54, 0.55≤f4 / f≤0.57, and 1.43≤|f5 / f|≤1.88; wherein 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 (which can also be understood as the equivalent focal length of the optical imaging lens). It should be noted that by more specifically limiting the size of the focal length of each lens, the power of the system is more reasonably dispersed and configured, thereby further strengthening the correction of various aberrations and improving the field of view angle and imaging quality. In addition, if the position of the lens focal length is not defined in the embodiment, it means that the focal length of the lens can be the focal length of the lens at the near optical axis. It should be emphasized that before the present application, the existing optical imaging lens for projection display cannot balance the imaging quality and large field of view angle, that is, the field of view angle is usually improved at the expense of the imaging quality, and it is difficult to ensure the imaging quality while achieving a large field of view angle. The present application achieves high-quality imaging output while improving the field of view angle and being small in size by controlling the focal length and surface structure of the five lenses.

[0067] Further, in a possible implementation, the connection between the five lenses can be spaced apart or bonded together by adhesion, which will be determined according to the actual application requirements, and is not limited here.

[0068] Further, in a possible implementation, the various lenses satisfy the following relationship:

[0069] 1.54≤n1≤1.67, 1.56≤n2≤1.75, 1.63≤n3≤1.76, 1.49≤n4≤1.57, and 1.54≤n5≤1.67; wherein 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 1.63 or 1.66 or 1.69 or 1.73, n2 is 1.56 or 1.57 or 1.58, n3 is 1.52 or 1.64 or 1.76, n4 is 1.49 or 1.52 or 1.57, and n5 is 1.62 or 1.64 or 1.74 or 1.75. It should be noted that by optimizing the design of the refractive index of the five lenses, the dispersion coefficient of the corresponding lens can be reasonably controlled to ensure the imaging quality and large field of view angle.

[0070] Further optionally, in order to better ensure the imaging quality, the embodiments of the present application further preferably limit the dispersion coefficients of the five lenses, and the dispersion coefficients of the various lenses satisfy: 46.3≤v1≤55.7, 23.2≤v2≤62.8, 23.2≤v3≤29.3, 62.4≤v4≤70.4, 52.1≤v5≤60.3; wherein 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. The Abbe number of the first lens is preferably 35.8 or 39.8 or 46.3 or 53.1, the Abbe number of the second lens is preferably 45 or 48.4 or 59.8 or 61.3, the Abbe number of the third lens is preferably 22.4 or 27.6 or 56.2, the Abbe number of the fourth lens is preferably 63.2 or 66.9 or 70.4, and the Abbe number of the fifth lens is preferably 23.1 or 29.7 or 43 or 60.3. It should be noted that in other embodiments of the present application, the Abbe numbers of the five lenses are not limited to those defined in the embodiments of the present application, and other dispersion coefficients that can ensure good matching relationship of the five lenses can also be used to ensure the final imaging quality.

[0071] Further optionally, in one possible embodiment, the first side surface of the first lens is convex, the second side surface of the first lens is concave; the first side surface of the second lens is convex, the second side surface of the second lens is convex or concave; the first side surface of the third lens is concave or convex near the optical axis, the second side surface of the third lens is concave; the first side surface of the fourth lens is concave or convex, the second side surface of the fourth lens is convex; and the first side surface of the fifth lens is convex, the second side surface of the fifth lens is concave near the optical axis. It should be noted that by limiting the surface shape structures of the corresponding side surfaces of the lenses as described above, the aberration generated between the lenses can be further effectively corrected, the optical sensitivity can be reduced, and the final imaging quality and field of view can be improved. In addition, it should be noted that the first side surface being convex means that the first side surface forms a convex shape towards the first side of the optical imaging lens group, the first side surface being concave means that the first side surface forms a concave shape towards the first side of the optical imaging lens group, the second side surface being convex means that the second side surface forms a convex shape towards the second side of the optical imaging lens group, and the second side surface being concave means that the second side surface forms a concave shape towards the second side of the optical imaging lens group. It should be emphasized that in other embodiments of the present application, the surface shape structures of all the lenses are not limited to be simultaneously limited as in the present embodiment, and the surface shape structures of at least one lens can also be limited, such as limiting the surface shape structures of the first side surface and the second side surface of the fifth lens, and not limiting the surface shape structures of the other lenses.

[0072] Further, in some embodiments, the surface shape of the lens is not entirely concave or convex on the side surface, and the surface shape of the lens can be a compound curved surface, or the near-axis part is curved and the edge part is not curved; in particular, when the lens surface is convex and the position of the convex surface is not defined, it means that the convex surface can be located at the near-axis of the lens surface; similarly, when the lens surface is concave and the position of the concave surface is not defined, it means that the concave surface can be located at the near-axis of the lens surface.

[0073] Further, in some embodiments, the surface shape of the lens is not entirely concave or convex on the side surface, and the surface shape of the lens can be a compound curved surface, or the near-axis part is curved and the edge part is not curved; in particular, when the lens surface is convex and the position of the convex surface is not defined, it means that the convex surface can be located at the near-axis of the lens surface; similarly, when the lens surface is concave and the position of the concave surface is not defined, it means that the concave surface can be located at the near-axis of the lens surface.

[0074] Further, in some embodiments, the surface shape of the lens is not entirely concave or convex on the side surface, and the surface shape of the lens can be a compound curved surface, or the near-axis part is curved and the edge part is not curved; in particular, when the lens surface is convex and the position of the convex surface is not defined, it means that the convex surface can be located at the near-axis of the lens surface; similarly, when the lens surface is concave and the position of the concave surface is not defined, it means that the concave surface can be located at the near-axis of the lens surface.

[0075] In addition, it should be noted that the optical imaging lens group disclosed in the embodiments of the present application can optionally be provided with at least one diaphragm, which can be located before the first lens (first side), between each lens, or after the last fifth lens (second side). The diaphragm can be an aperture diaphragm or a field diaphragm, which can be used to reduce stray light and improve image display quality.

[0076] Further, in some embodiments, the optical imaging lens group in the embodiments of the present application also satisfies the following optical characteristics:

[0077] The plurality of lenses in the optical imaging lens assembly are arranged in sequence along the optical axis from the entrance pupil position to the exit pupil position. The exit pupil position of the optical imaging lens assembly corresponds to the curved image, i.e., corresponds to the second side of the optical imaging lens assembly. The entrance pupil position of the optical imaging lens assembly corresponds to the planar image, i.e., corresponds to the first side of the optical imaging lens assembly. It should be noted that please refer to Figures 1a to 2b ( Figure 2b For example, in the optical imaging lens assembly containing six lenses), the lens surface close to the exit pupil position and opposite to the exit pupil position in the plurality of lenses (i.e., the lens surface closest to the curved image) is a concave surface. The optical axis and the concave surface intersect to form an intersection point. The distance between the intersection point and the exit pupil position is the exit pupil distance. The exit pupil distance is 1.5-6.0 mm, and preferably, the exit pupil distance is 2-3.5 mm. It should be noted that by limiting the surface structure of the lens close to the curved image in the plurality of on-axis lenses of the optical imaging lens assembly and the corresponding exit pupil distance, it can be matched with the corresponding curved scanning image, so that clear imaging from the curved image to the planar image is realized.

[0078] In addition, it should be further explained that please continue to refer to Figure 2b :

[0079] Entrance pupil: The entrance pupil is the effective aperture of the incident light beam. It is the image formed by the aperture stop to the front optical system. It is the conjugate of the aperture stop in the object space. The entrance pupil corresponds to the exit pupil.

[0080] Entrance pupil position: The entrance pupil position is the position point of the image formed by the aperture stop to the front optical system. The calculation of the entrance pupil position is to regard the center of the aperture stop as an object point, and to perform ray tracing to the front optical system to obtain the intersection coordinates of the point on the optical axis. Usually, the distance from the first lens surface is taken as the entrance pupil distance.

[0081] 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.

[0082] Exit pupil position: The exit pupil position is the position point of the image formed by the aperture stop to the rear optical system. The calculation of the exit pupil position is to regard the center of the aperture stop as an object point, and to perform ray tracing to the rear optical system to obtain the intersection coordinates of the point on the optical axis. Usually, the distance from the last lens surface is taken as the exit pupil distance.

[0083] Measurement of the exit pupil position: A point light source is set at the center of the entrance pupil position. The best imaging position of the point light source is the exit pupil position through the imaging of the designed lens.

[0084] Further specifically, as Figure 2b shown, from left to right, i.e., from the first side to the second side, in sequence are the entrance pupil (entrance pupil position), the optical imaging lens assembly, and the exit pupil (exit pupil position).

[0085] Example One

[0086] Figure 3 A structural schematic diagram of an optical imaging lens provided by an embodiment of the present application. The optical imaging lens comprises first lens 11, second lens 12, third lens 13, fourth lens 14 and fifth lens 15 arranged in sequence on the same optical axis from the first side (i.e., the side where the diaphragm 01 in FIG. 1 is located) to the second side (i.e., the side where the scanning curved surface 02 in FIG. 1 is located). Figure 3 Figure 3

[0087] In this embodiment, each 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 has a gap, and 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-bonding lenses.

[0088] The focal lengths of the first lens 11 to the fifth lens 15 from the first side to the second side are negative, positive, negative, positive and negative in sequence.

[0089] The first side surface of the first lens 11 is a convex surface, and the second side surface is a concave surface.

[0090] The first side surface and the second side surface of the second lens 12 are both convex surfaces.

[0091] The first side surface and the second side surface of the third lens 13 are both concave surfaces.

[0092] The first side surface of the fourth lens 14 is a convex surface, and the second side surface is a convex surface near the optical axis.

[0093] The first side surface of the fifth lens 15 is a convex surface, and the second side surface is a concave surface near the optical axis.

[0094] In this embodiment, the focal lengths of the first lens 11 to the fifth lens 15 in the optical imaging lens satisfy the following relationship:

[0095] f1 / f is -18.12, f2 / f is 0.87, f3 / f is -0.39, f4 / f is 0.56 and f5 / f is -2.88; wherein 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.

[0096] The refractive index and the dispersion coefficient of the first lens 11 to the fifth lens 15 in the optical imaging lens satisfy the following conditions respectively:

[0097] ​​n1 is 1.69, n2 is 1.57, n3 is 1.64, n4 is 1.52, and n5 is 1.75. Wherein, n1-n5 represent the refractive index of the first lens 11 to the fifth lens 15 respectively; the Abbe number of the first lens is 39.8, the Abbe number of the second lens is 45, the Abbe number of the third lens is 22.4, the Abbe number of the fourth lens is 66.9, and the Abbe number of the fifth lens is 29.7.

[0098] The optical imaging lens provided by the embodiment one has an equivalent focal length of 2.60mm, an aperture value of 1.3, a half field angle of 10 degrees, a scanning radius of 2mm, and an entrance pupil diameter of 2mm. The preferred parameters of the curvature radius, thickness, refractive index, and dispersion coefficient of each lens in the imaging of the scanning surface 02 are shown in Table 1:

[0099] Table 1 Structure parameters of the optical imaging lens in embodiment one

[0100] Surface Lens Number Surface Form Radius of Curvature Thickness / Spacing Material Refractive Index Dispersion Coefficient 0 Imaging Plane Plane Infinity Infinity 1 Stop 01 Infinity 1 2 First Lens 11 Aspheric 24.02 1.35 1.69 39.8 3 Aspheric 12.92 1.30 4 Second Lens 12 Aspheric 1.54 1.39 1.57 45 5 Aspheric -5.70 0.23 6 Third Lens 13 Aspheric -12.01 0.60 1.64 22.4 7 Aspheric 0.71 0.29 8 Fourth Lens 14 Aspheric 4.66 1.11 1.52 66.9 9 Aspheric -0.85 0.10 10 Fifth Lens 15 Aspheric 1.00 0.65 1.75 29.7 11 Aspheric 0.61 0.49 12 Scanning Surface 02 Spherical 2

[0101] It should be noted that Table 1 is the detailed structure data of the optical imaging lens in embodiment one, wherein 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 a curvature radius of "infinity" in the imaging plane means a plane.

[0102] Further, the aspherical conic coefficients of the surfaces corresponding to the first lens 11 to the fifth lens 15 are shown in Table 2:

[0103] Table 2 Aspherical conic coefficient data of different lens surfaces in embodiment one

[0104]

[0105]

[0106] Table 2 is the aspherical coefficient data in embodiment one, wherein 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.

[0107] Further, when the image light corresponding to the projection scanning surface is projected by using the above optical imaging lens, the optical transfer function curve is as shown in Figure 4 , the field curvature distortion curve is as shown in Figure 5 , and the axial chromatic aberration curve is as shown in Figure 6The modulation transfer function (MTF) represents the comprehensive resolution level of an optical system, the field curvature distortion curve represents the F-Tan(theta) distortion size value (percentage) under different field angles, and the vertical axis chromatic aberration curve represents the size of the chromatic aberration perpendicular to the axial direction.

[0108] By Figures 4-6 It can be observed that the optical imaging lens group of the embodiment one has good imaging resolution in the full field of view range, small optical system distortion and chromatic aberration, and thus can clearly image the curved surface image scanned by the fiber scanner, and all have good imaging effects.

[0109] Of course, in actual applications, the optical imaging lens group can also include display elements, housings, etc., the display elements 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 that the curved surface image scanned by the image source (such as the fiber scanner) can be imaged on a plane to achieve clear imaging.

[0110] Embodiment two

[0111] Figure 7 A structural schematic diagram of an optical imaging lens group provided by the embodiment of the present application is shown. The optical imaging lens group includes a first lens 31, a second lens 32, a third lens 33, a fourth lens 34, and a fifth lens 35 arranged in sequence on the same optical axis from a first side (i.e., a side on which the diaphragm 03 in the above embodiment is located) to a second side (i.e., a side on which the curved surface 04 in the above embodiment is located). Figure 7 Figure 7 In the above embodiment, each 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 has a gap, and 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-adhesive lenses.

[0112] In the above embodiment, each 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 has a gap, and 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-adhesive lenses.

[0113] The focal lengths of the first lens 31 to the fifth lens 35 from the first side to the second side are negative, positive, negative, positive, and negative in sequence.

[0114] The first side surface of the first lens 31 is a convex surface, and the second side surface is a concave surface.

[0115] The first side surface and the second side surface of the second lens 32 are both convex surfaces.

[0116] The first side surface and the second side surface of the third lens 33 are both concave surfaces.

[0117] 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. ​

[0118] The first side surface of the fifth lens 35 is a convex surface, and the second side surface is a concave surface at the near optical axis.

[0119] In the embodiment, the focal lengths of the first lens 31 to the fifth lens 35 in the optical imaging lens satisfy the following relationship:

[0120] f1 / f is -21.59, f2 / f is 0.89, f3 / f is -0.40, f4 / f is 0.55, and f5 / f is -2.58; wherein 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.

[0121] The refractive indices and dispersion coefficients of the first lens 31 to the fifth lens 35 in the optical imaging lens satisfy the following conditions, respectively:

[0122] n1 is 1.63, n2 is 1.56, n3 is 1.64, n4 is 1.52, and n5 is 1.64; wherein n1-n5 represent the refractive indices of the first lens 31 to the fifth lens 35, respectively; the Abbe number of the first lens is 35.8, the Abbe number of the second lens is 48.4, the Abbe number of the third lens is 22.4, the Abbe number of the fourth lens is 66.9, and the Abbe number of the fifth lens is 23.1.

[0123] In the optical imaging lens provided by the second embodiment of the present application, the equivalent focal length of the optical imaging lens as a whole 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, refractive index, and dispersion coefficient of each lens in the imaging of the scanning curved surface 04 are shown in Table 3:

[0124] Table 3 Structure parameters of the optical imaging lens in the second embodiment

[0125] Surface Lens Number Surface Form Radius of Curvature Thickness / Spacing Material Refractive Index Dispersion Coefficient 0 Imaging Plane Plane Infinity Infinity 1 Stop 03 Infinity 1 2 First Lens 31 Aspheric 21.95 1.40 1.63 35.8 3 Aspheric 13.14 1.35 4 Second Lens 32 Aspheric 1.53 1.39 1.56 48.4 5 Aspheric -5.80 0.23 6 Third Lens 33 Aspheric -11.41 0.60 1.64 22.4 7 Aspheric 0.71 0.24 8 Fourth Lens 34 Aspheric 4.61 1.13 1.52 66.9 9 Aspheric -0.81 0.10 10 Fifth Lens 35 Aspheric 0.89 0.60 1.64 23.1 11 Aspheric 0.54 0.49 12 Scanning Surface 04 Spherical 2

[0126] It should be noted that Table 3 is the detailed structure data of the optical imaging lens in the second embodiment, wherein the units of the curvature radius, thickness, and focal length are all millimeters, and surfaces 0-12 represent the surfaces from the first side to the second side in order; the optical surface with a curvature radius of "infinity" in the imaging plane means a plane.

[0127] Further, the aspheric conic coefficients of the surfaces corresponding to the first lens 31 to the fifth lens 35 are shown in Table 4:

[0128] Table 4 Aspheric conic coefficient data of different lens surfaces in the second embodiment

[0129] Surface K A4 A6 A8 2 1.51E+02 -3.35E-02 6.27E-03 -1.39E-03 3 -4.00E+02 -6.75E-02 1.53E-02 -1.94E-03 4 -1.84E+00 1.12E-02 -1.30E-02 -8.97E-03 5 -6.54E+01 2.61E-01 -3.18E-01 1.05E-01 6 5.20E+01 -1.22E-01 5.20E-03 3.12E-02 7 -3.91E+00 -3.93E-01 3.14E-01 -9.35E-02 8 1.34E+01 -2.62E-01 3.69E-01 -1.41E-01 9 -2.69E+00 -6.72E-02 2.46E-01 -5.25E-02 10 -7.78E-01 -4.56E-03 2.02E-01 -2.20E-01 11 -5.04E-01 -1.95E+00 2.28E+00 -3.27E+00

[0130] Table 4 is the aspherical surface coefficient data in Example 2, wherein k is the conic coefficient in the aspherical surface equation, and A4 to A8 represent the 4th to 8th order aspherical surface coefficients of each surface.

[0131] Further, when the image light corresponding to the scanning surface is projected by using the optical imaging lens group, the optical transfer function curve is as shown in Figure 8 , the field curvature distortion curve is as shown in Figure 9 , and the axial chromatic aberration curve is as shown in Figure 10 ; wherein 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 value (percentage) under different field angles, and the axial chromatic aberration curve represents the size of the chromatic aberration perpendicular to the axial direction.

[0132] It can be observed from Figures 8-10 that the optical imaging lens group in Example 2 has good imaging resolution in the full field of view, small optical system distortion and chromatic aberration, and thus can clearly image the scanning surface image of the fiber scanner, and all have good imaging effects.

[0133] Of course, in actual applications, the optical imaging lens group can further include a display element and a housing, 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 that the curved surface image scanned by the image source (such as a fiber scanner) can be imaged on a plane to achieve clear imaging.

[0134] Example Three

[0135] Figure 11 A structural schematic diagram of an optical imaging lens group according to an embodiment of the present application is shown in FIG. 1. 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 arranged in sequence on the same optical axis from a first side (i.e., the side where the diaphragm 05 in Figure 11 is located) to a second side (i.e., the side where the scanning curved surface 06 in Figure 11 is located).

[0136] In this embodiment, each 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 has a spacing, and 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-adhesive lenses.

[0137] The focal lengths of the first lens 51 to the fifth lens 55 from the first side to the second side are negative, positive, negative, positive, and negative in sequence.

[0138] The first side surface of the first lens 51 is a convex surface, and the second side surface is a concave surface.

[0139] The first side surface and the second side surface of the second lens 52 are both convex surfaces.

[0140] The first side surface of the third lens 53 is a convex surface at the near optical axis, and the second side surface is a concave surface.

[0141] The first side surface of the fourth lens 54 is a concave surface, and the second side surface is a convex surface at the near optical axis.

[0142] The first side surface of the fifth lens 55 is a convex surface, and the second side surface is a concave surface at the near optical axis.

[0143] In the present embodiment, the focal lengths of the first lens 51 to the fifth lens 55 in the optical imaging lens group satisfy the following relationship:

[0144] f1 / f is -15.68, f2 / f is 0.97, f3 / f is -0.58, f4 / f is 0.56, and f5 / f is -1.43; wherein 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.

[0145] The refractive indices and the dispersion coefficients of the first lens 51 to the fifth lens 55 in the optical imaging lens group satisfy the following conditions, respectively:

[0146] n1 is 1.66, n2 is 1.57, n3 is 1.52, n4 is 1.57, and n5 is 1.74; wherein n1-n5 represent the refractive indices of the first lens 51 to the fifth lens 55, respectively; the Abbe number of the first lens is 53.1, the Abbe number of the second lens is 59.8, the Abbe number of the third lens is 56.2, the Abbe number of the fourth lens is 63.2, and the Abbe number of the fifth lens is 43.

[0147] In the optical imaging lens group provided by the third embodiment of the present application, the equivalent focal length of the optical imaging lens group as a whole 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, the thickness parameter, the refractive index, and the dispersion coefficient of each lens in the imaging of the scanning curved surface 06 are shown in Table 5:

[0148] Table 5 Structure parameters of the optical imaging lens group in the third embodiment

[0149] Surface Lens Number Surface Form Radius of Curvature Thickness / Spacing Material Refractive Index Dispersion Coefficient 0 Imaging Plane Plane Infinity Infinity 1 Stop 05 Infinity 1 2 First Lens 51 Aspheric 21.46 1.11 1.66 53.1 3 Aspheric 11.65 1.05 4 Second Lens 52 Aspheric 1.50 1.37 1.57 59.8 5 Aspheric -16.96 0.20 6 Third Lens 53 Aspheric 52.98 0.60 1.52 56.2 7 Aspheric 0.94 0.46 8 Fourth Lens 54 Aspheric -8.22 1.06 1.57 63.2 9 Aspheric -0.78 0.10 10 Fifth Lens 55 Aspheric 1.08 0.60 1.74 43 11 Aspheric 0.59 0.49 12 Scanning Surface 06 Spherical 2

[0150] It should be noted that Table 5 is the detailed structure data of the optical imaging lens group of Example 3, wherein the units of the curvature radius, the thickness and the focal length are millimeters, and the surfaces 0-12 represent the surfaces from the first side to the second side in sequence; the optical surface with the curvature radius of "infinity" in the imaging plane means a plane.

[0151] Further, the aspheric conic coefficients of the surfaces corresponding to the first lens 51 to the fifth lens 55 are shown in Table 6 as follows:

[0152] Table 6: Aspheric conic coefficients of different lens surfaces in Example 3

[0153] Surface K A4 A6 A8 2 1.51E+02 -3.35E-02 6.27E-03 -1.39E-03 3 -4.00E+02 -6.75E-02 1.53E-02 -1.94E-03 4 -1.84E+00 1.12E-02 -1.30E-02 -8.97E-03 5 -6.54E+01 2.61E-01 -3.18E-01 1.05E-01 6 5.20E+01 -1.22E-01 5.20E-03 3.12E-02 7 -3.91E+00 -3.93E-01 3.14E-01 -9.35E-02 8 1.34E+01 -2.62E-01 3.69E-01 -1.41E-01 9 -2.69E+00 -6.72E-02 2.46E-01 -5.25E-02 10 -7.78E-01 -4.56E-03 2.02E-01 -2.20E-01 11 -5.04E-01 -1.95E+00 2.28E+00 -3.27E+00

[0154] Table 6 is the aspheric coefficient data in Example 3, wherein k is the conic coefficient in the aspheric curve equation, and A4 to A8 represent the 4th to 8th order aspheric coefficients of each surface.

[0155] Further, when the image light corresponding to the scanning surface of the optical fiber scanner is projected by using the optical imaging lens group, the Modulation Transfer Function (MTF) curve is as shown in Figure 12 , the field curvature distortion curve is as shown in Figure 13 , and the axial chromatic aberration curve is as shown in Figure 14 ; wherein the Modulation Transfer Function (MTF) curve represents the comprehensive resolution level of an optical system, the field curvature distortion curve represents the F-Tan(theta) distortion size value (percentage) under different field angles, and the axial chromatic aberration curve represents the size of the chromatic aberration perpendicular to the axial direction.

[0156] It can be observed from Figures 12-14 that the imaging resolution of the optical imaging lens group of Example 3 is good in the full field of view range, the optical system distortion and the chromatic aberration are small, so the optical imaging lens group can clearly image the scanning surface image of the optical fiber scanner, and all have good imaging effects.

[0157] Of course, in actual application, the optical imaging lens group can also include a display element and a shell, 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 shell, that is, the curved surface image scanned by the image source (such as an optical fiber scanner) can be imaged on a plane to realize clear imaging.

[0158] Example 4

[0159] Figure 15 A structure diagram of an optical imaging lens group provided in the embodiment of the present application. The optical imaging lens group includes a first side (i.e., a side where the diaphragm 07 in Figure 15 is located) to a second side (i.e., a side where the diaphragm 07 in Figure 15The 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 sequentially arranged on the same optical axis of the scanning surface 08 (on the side of the scanning surface 08 in the optical imaging lens group 70). It should be noted that the first lens 71 provided in the embodiment of the present application corresponds to an additional lens, the focal length of the second lens 72, the third lens 73, the fourth lens 74, the fifth lens 75 and the sixth lens 76 corresponds to the positive or negative of the focal length of the five lenses defined in the claims, and the "first", "second" and the like in the embodiment have no importance or order difference of the lenses, but only for naming and distinguishing different elements.

[0160] In the embodiment, there is a gap between each two adjacent lenses of 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, and 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-adhesive lenses.

[0161] The focal length of the first lens 71 to the sixth lens 76 from the first side to the second side is positive, negative, positive, negative, positive and negative in turn.

[0162] The first side surface of the first lens 71 is a concave surface, and the second side surface is a convex surface.

[0163] The first side surface of the second lens 72 is a convex surface, and the second side surface is a concave surface at the near optical axis.

[0164] The first side surface of the third lens 73 is a convex surface, and the second side surface is a concave surface.

[0165] The first side surface and the second side surface of the fourth lens 74 are both concave surfaces.

[0166] The first side surface of the fifth lens 75 is a concave surface, and the second side surface is a convex surface at the near optical axis.

[0167] The first side surface of the sixth lens 76 is a convex surface, and the second side surface is a concave surface at the near optical axis.

[0168] In the embodiment, the focal length of the first lens 71 to the sixth lens 76 in the optical imaging lens group satisfies the following relationship:

[0169] f1 / f is 45.61, f2 / f is -26.43, f3 / f is 0.95, f4 / f is -0.46, f5 / f is 0.52, and f6 / f is -1.53; wherein 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.

[0170] The refractive indices and dispersion coefficients of the first lens 71 to the sixth lens 76 in the optical imaging lens group satisfy the following conditions respectively:

[0171] n1 is 1.62, n2 is 1.62, n3 is 1.56, n4 is 1.76, n5 is 1.56, and n6 is 1.67. Wherein, n1-n6 represent the refractive indices of the first lens 71 to the sixth lens 76 respectively; the Abbe number of the first lens is 60.3, the Abbe number of the second lens is 60.4, the Abbe number of the third lens is 63.7, the Abbe number of the fourth lens is 27.6, the Abbe number of the fifth lens is 64, and the Abbe number of the sixth lens is 52.

[0172] In the optical imaging lens group provided by the fourth embodiment of the present application, the equivalent focal length of the optical imaging lens group as a whole 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, refractive index and dispersion coefficient of each lens in the imaging of the scanning surface 08 are shown in Table 7:

[0173] Table 7 Structure parameters of the optical imaging lens group in the fourth embodiment

[0174] Surface Lens Number Surface Form Radius of Curvature Thickness / Spacing Material Refractive Index Dispersion Coefficient 0 Imaging Plane Plane Infinity Infinity 1 Stop 07 Infinity 1 2 First Lens 71 Spherical -50.18 0.71 1.62 60.3 3 Spherical -30.08 0.10 4 Second Lens 72 Aspheric 16.39 0.76 1.62 60.4 5 Aspheric 11.65 0.96 6 Third Lens 73 Aspheric 1.48 1.36 1.56 63.7 7 Aspheric -18.25 0.18 8 Fourth Lens 74 Aspheric 153.05 0.60 1.76 27.6 9 Aspheric 0.91 0.30 10 Fifth Lens 75 Aspheric -18.79 1.03 1.56 64 11 Aspheric -0.75 0.10 12 Sixth Lens 76 Aspheric 1.01 0.61 1.67 52 13 Aspheric 0.56 0.50 14 Scanning Surface 08 Spherical 2

[0175] It should be noted that Table 7 is the detailed structure data of the optical imaging lens group in the fourth embodiment, wherein 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 order; the optical surface with a curvature radius of "infinity" in the imaging plane means a plane.

[0176] Further, the aspherical conic coefficients of the surfaces corresponding to the first lens 71 to the sixth lens 76 are shown in Table 8:

[0177] Table 8 Aspherical conic coefficient data of different lens surfaces in the fourth embodiment

[0178]

[0179]

[0180] Table 8 is the aspherical coefficient data in the fourth embodiment, wherein 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.

[0181] Further, it is tested that when the image light corresponding to the projection scanning surface is projected by using the above optical imaging lens group, the optical transfer function curve is as shown in Figure 16 , the field curvature distortion curve is as shown in Figure 17 , and the axial chromatic aberration curve is as shown in Figure 18The modulation transfer function (MTF) represents the comprehensive resolution level of an optical system, the field curvature distortion curve represents the F-Tan(theta) distortion value (percentage) at different field angles, and the vertical axis chromatic aberration curve represents the chromatic aberration size in the direction perpendicular to the axial direction.

[0182] By Figures 16-18 It can be observed that the optical imaging lens group of Example Four has good imaging resolution in the full field of view, small optical system distortion and chromatic aberration, and thus can clearly image the curved surface image scanned by the fiber scanner, and all have good imaging effects.

[0183] Of course, in actual applications, the optical imaging lens group can also include display elements, housings, etc., the display elements 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 that the curved surface image scanned by the image source (such as a fiber scanner) can be imaged on a plane to achieve clear imaging.

[0184] Example Five

[0185] Figure 19 A structural schematic diagram of an optical imaging lens group provided by the embodiment of the present application. The optical imaging lens group includes a first lens 91, a second lens 92, a third lens 93, a fourth lens 94, and a fifth lens 95 arranged in sequence on the same optical axis from a first side (i.e., a side on which the stop 09 in the above embodiment is located) to a second side (i.e., a side on which the curved surface 10 in the above embodiment is located). Figure 19 Figure 19

[0186] In the present embodiment, each two adjacent lenses among the first lens 91, the second lens 92, the third lens 93, the fourth lens 94, and the fifth lens 95 has a spacing, and the first lens 91, the second lens 92, the third lens 93, the fourth lens 94, and the fifth lens 95 are five single non-adhesive lenses.

[0187] The focal lengths of the first lens 91 to the fifth lens 95 from the first side to the second side are negative, positive, negative, positive, and negative in sequence.

[0188] The first side surface of the first lens 91 is a convex surface, and the second side surface is a concave surface.

[0189] The first side surface of the second lens 92 is a convex surface, and the second side surface is a concave surface.

[0190] The first side surface of the third lens 93 is a convex surface, and the second side surface is a concave surface.

[0191] The first side surface of the fourth lens 94 is a concave surface, and the second side surface is a convex surface.​​

[0192] The first side surface of the fifth lens 95 is a convex surface, the second side surface is a concave surface at the near optical axis, and the second side surface is a convex surface at the far optical axis.

[0193] In the embodiment, the focal lengths of the first lens 91 to the fifth lens 95 in the optical imaging lens group satisfy the following relationship:

[0194] f1 / f is -1.54, f2 / f is 0.68, f3 / f is -0.54, f4 / f is 0.57, and f5 / f is -3.50; wherein f1 is the focal length of the first lens 91, f2 is the focal length of the second lens 92, f3 is the focal length of the third lens 93, f4 is the focal length of the fourth lens 94, f5 is the focal length of the fifth lens 95, and f is the equivalent focal length of the optical imaging lens group.

[0195] The refractive indices and dispersion coefficients of the first lens 91 to the fifth lens 95 in the optical imaging lens group satisfy the following conditions respectively:

[0196] n1 is 1.73, n2 is 1.58, n3 is 1.76, n4 is 1.49, and n5 is 1.62; wherein n1-n5 represent the refractive indices of the first lens 91 to the fifth lens 95 respectively; the Abbe number of the first lens is 46.3, the Abbe number of the second lens is 61.3, the Abbe number of the third lens is 27.6, the Abbe number of the fourth lens is 70.4, and the Abbe number of the fifth lens is 60.3.

[0197] In the optical imaging lens group provided by the embodiment, the equivalent focal length of the optical imaging lens group as a whole is 2.6 mm, the aperture value is 1.30, the half field angle is 10 degrees, the scanning radius is 1.8 mm, and the entrance pupil diameter is 2 mm. The preferred parameters of the curvature radius, thickness, refractive index, and dispersion coefficient of each lens in the imaging of the scanning curved surface 10 are shown in Table 9:

[0198] Table 9 Structure parameters of the optical imaging lens group in Example Five

[0199] Surface Lens Number Surface Form Radius of Curvature Thickness / Spacing Material Refractive Index Dispersion Coefficient 0 Imaging Plane Plane Infinity Infinity 1 Stop 09 Infinity 1 2 First Lens 51 Aspheric 11.23 1.94 1.73 46.3 3 Aspheric 2.15 0.37 4 Second Lens 52 Aspheric 0.97 1.31 1.58 61.3 5 Aspheric 7.65 0.34 6 Third Lens 53 Aspheric 4.78 0.63 1.76 27.6 7 Aspheric 0.83 0.34 8 Fourth Lens 54 Aspheric 34.38 1.11 1.49 70.4 9 Aspheric -0.74 0.10 10 Fifth Lens 55 Aspheric 1.14 0.77 1.62 60.3 11 Aspheric 0.70 0.50 12 Scanning Surface 10 Spherical 2

[0200] It should be noted that Table 9 is the detailed structure data of the optical imaging lens group in Example Five, wherein the units of the curvature radius, thickness, and focal length are all millimeters, and surfaces 0-12 represent the surfaces from the first side to the second side in order; the optical surface with a curvature radius of "infinity" in the imaging plane means a plane.

[0201] Further, the aspheric conic coefficients of the surfaces corresponding to the first lens 91 to the fifth lens 95 are shown in Table 10:

[0202] Table 10 Aspheric conic coefficient data of different lens surfaces in Example Five

[0203] Surface K A4 A6 A8 2 5.68E+01 -7.44E-03 9.83E-03 -4.02E-03 3 -1.61E+01 -6.07E-02 4.00E-02 -7.74E-03 4 -2.35E+00 2.42E-02 5.98E-03 -1.45E-02 5 -3.47E+02 2.42E-01 -3.25E-01 1.39E-01 6 -1.43E+02 -1.59E-01 7.35E-03 7.24E-02 7 -5.24E+00 -2.98E-01 2.20E-01 -7.42E-02 8 4.00E+02 -3.52E-01 3.24E-01 -1.42E-01 9 -2.13E+00 -1.25E-01 1.00E-01 -1.97E-02 10 -6.35E-01 -5.57E-02 1.76E-02 -2.62E-01 11 -6.65E-01 -1.95E+00 1.81E+00 -8.87E-01

[0204] Table 10 is the aspherical surface coefficient data in Example 5, wherein k is the conic coefficient in the aspherical surface equation, and A4 to A8 represent the 4th to 8th order aspherical surface coefficients of each surface.

[0205] Further, when the image light corresponding to the scanning surface is projected by using the optical imaging lens group, the optical transfer function curve is as shown in Figure 20 , the field curvature distortion curve is as shown in Figure 21 , and the axial chromatic aberration curve is as shown in Figure 22 ; wherein 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 value (percentage) at different field angles, and the axial chromatic aberration curve represents the size of the chromatic aberration perpendicular to the axial direction.

[0206] It can be observed from Figures 20-22 that the optical imaging lens group in Example 5 has good imaging resolution in the full field of view range, small optical system distortion and chromatic aberration, and thus can clearly image the scanning surface image of the fiber scanner, and all have good imaging effects.

[0207] Of course, in actual applications, the optical imaging lens group can further include a display element and a housing, 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 that the curved surface image scanned by the image source (such as the fiber scanner) can be imaged on a plane to achieve clear imaging.

[0208] Scanning display device

[0209] The foregoing optical imaging lens group can be combined with a fiber scanner (or a corresponding fiber scanning module) to form a scanning display device in the embodiments of the present application (such as Figure 1a , 1b , wherein the optical imaging lens group is arranged on the light path of the fiber scanner), wherein the first side of the optical imaging lens group faces the scanning direction of the fiber scanner, and the preferred mode is that the optical imaging lens group is coaxial with the central optical axis of the fiber scanner. Of course, the structure and general principle of the fiber scanner can refer to the corresponding content of the foregoing Figure 1a , 1b , and thus will not be described in detail here.

[0210] Near-eye display device

[0211] In this application, the scanning display device can be further applied to a near-eye display device, and can be used in conjunction with a near-eye display module to form the near-eye display device in the embodiments of this application, for use as a head-mounted AR device (such as AR glasses). The scanning display device is disposed in the near-eye display module.

[0212] The near-eye display module may include: a light source, processing and control circuitry, a wearable frame structure, and a waveguide. The image beam output from the light source enters the scanning display device, where it is scanned by a fiber optic scanner and output to the optical display lens assembly. The scanning surface of the fiber optic scanner (see reference) Figure 3 The scan surface 02 and its corresponding Figure 2a The scanning surface 230 in the image is converted into an imaging plane after passing through the optical display lens group (see reference). Figure 2a The imaging plane 240 in the waveguide is coupled into the waveguide as the entrance pupil surface, and then coupled out through the waveguide to enter the human eye.

[0213] As another possible implementation, the scanning display device can be further combined with the near-eye display module to form the near-eye display device in the embodiments of this application, and used as a head-mounted VR device (such as a VR helmet / glasses). The scanning display device is disposed in the near-eye display module.

[0214] In this embodiment, by rationally optimizing the focal length of the five coaxial lenses in the optical imaging lens group, the optical power of the system can be reasonably dispersed, the aberrations generated by the lenses can be reduced, and the purpose of correcting various aberrations can be achieved. While improving the field of view, clear imaging of the image surface is achieved. By limiting and optimizing the refractive index, dispersion coefficient, and surface structure of the five coaxial lenses, the imaging quality and field of view are further improved. By limiting and optimizing the design of the five coaxial lenses into aspherical surface structures, the overall structure of the optical imaging lens group is more compact while further improving the imaging quality, thus meeting the production requirements for miniaturization of lens products.

[0215] The above description is merely a preferred embodiment of this application. Each embodiment is only used to illustrate the technical solution of this application and is not intended to limit this application. Any technical solution that can be obtained by those skilled in the art through logical analysis, reasoning or effective experimentation based on the concept of this application should be within the scope of this application.

[0216] The various embodiments in this application are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0217] The expressions "first", "second", "the first", or "the second" used in various embodiments of the disclosure can modify various components regardless of order and / or importance, but the expressions do not limit the corresponding components. The above expressions are configured only 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, characterized in that, The first side of the optical imaging lens corresponds to a plane image, the second side of the optical imaging lens corresponds to a curved surface image, the optical imaging lens comprises at least a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged in sequence on the same optical axis from the first side to the second side, the focal lengths of the first lens to the fifth lens correspond to negative, positive, negative, positive and negative respectively; each of the lenses satisfies the following relationship: 1.54≤|f1 / f|≤21.59, 0.68≤f2 / f≤0.97, 0.39≤|f3 / f|≤0.54, 0.55≤f4 / f≤0.57 and 1.43≤|f5 / f|≤2.88; wherein 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; the exit pupil distance of the optical imaging lens is 1.5-6.0mm.

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

3. The optical imaging lens according to claim 2, wherein, Each of the lenses satisfies the following relationship: 1.54≤n1≤1.67, 1.56≤n2≤1.75, 1.63≤n3≤1.76, 1.49≤n4≤1.57 and 1.54≤n5≤1.67; wherein 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 each of the lenses satisfy: 46.3≤v1≤55.7, 23.2≤v2≤62.8, 23.2≤v3≤29.3, 62.4≤v4≤70.4 and 52.1≤v5≤60.3; wherein 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 according to claim 3, wherein, The n1 is 1.63 or 1.66, the n2 is 1.56 or 1.57 or 1.58, the n3 is 1.64 or 1.76, the n4 is 1.49 or 1.52 or 1.57, and the n5 is 1.62 or 1.

64. The dispersion coefficients of each of the lenses satisfy: the Abbe number of the first lens is 46.3 or 53.1, the Abbe number of the second lens is 45 or 48.4 or 59.8 or 61.3, the Abbe number of the third lens is 27.6, the Abbe number of the fourth lens is 63.2 or 66.9 or 70.4, and the Abbe number of the fifth lens is 60.

3.

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

6. The optical imaging lens according to any one of claims 1-5, wherein, The first side surface of the third lens is concave or convex at the near optical axis, and the second side surface of the third lens is concave.

7. The optical imaging lens according to claim 6, wherein, The first side surface of the first lens is convex, and the second side surface of the first lens is concave; the first side surface of the second lens is convex, and the second side surface of the second lens is convex or concave; The first side surface and the second side surface of the first lens to the fifth lens are aspherical surface structures.

8. A scanning display device, characterized by The optical imaging lens group according to any one of the preceding claims 1 to 7 is used for scanning and emitting light of an image to be displayed. The optical fiber scanner comprises an actuator and an optical fiber fixed on the actuator, and a part of the optical fiber beyond the actuator forms an optical fiber cantilever, which is driven by the actuator to perform two-dimensional scanning.

9. A near-eye display device, comprising: The near-eye display device is used as a head-mounted augmented reality device and comprises at least a near-eye display module and the scanning display device according to claim 8, which is arranged in the near-eye display module.

10. A near-eye display device, comprising: The near-eye display device is used as a head-mounted virtual reality device and comprises at least a near-eye display module and the scanning display device according to claim 8, which is arranged in the near-eye display module.

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