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 and miniaturization in the near-eye display scenario.

[0005] The optical imaging lens provided by the embodiments of the present application 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 coaxially, and the focal lengths of the first lens to the fifth lens are negative, negative, positive, negative and positive respectively.

[0006] Optionally, -0.7≤f4 / f≤-0.3 and 0.39≤f5 / f≤0.59, wherein 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.

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

[0008] Optionally, the various lenses also satisfy the following relationship: -4.76≤f1 / f≤-2.66, -1.26≤f2 / f≤-2.24 and 0.39≤f3 / f≤0.43, 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, and f is the focal length of the optical imaging lens.

[0009] The various lenses also satisfy the following relationship: 1.7≤n1≤1.73, 1.67≤n2≤1.76, 1.56≤n3≤1.61, 1.75≤n4≤1.76, 1.62≤n5≤1.63; 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: 28.7≤v1≤39.1, 27.6≤v2≤33.7, 60.7≤v3≤64, 27.6≤v4≤28.6, 58≤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 1.7 or 1.71 or 1.73, n2 is 1.67 or 1.75 or 1.76, n3 is 1.56 or 1.60 or 1.61, n4 is 1.75 or 1.76, and n5 is 1.62 or 1.63.

[0012] The dispersion coefficients of the various lenses satisfy: the Abbe number of the first lens is 28.7 or 31.1 or 39.1, the Abbe number of the second lens is 27.6 or 29.8 or 33.7, the Abbe number of the third lens is 60.7 or 61.6 or 64, the Abbe number of the fourth lens is 27.6 or 28.6, and the Abbe number of the fifth lens is 58 or 60.3.

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

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

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

[0016] The first side surface and the second side surface of the first lens to the fifth lens are all 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] This application embodiment also provides a scanning display device, which includes a fiber optic scanner and the aforementioned optical imaging lens group. The fiber optic scanner is used to scan and emit light of an image to be displayed, and the optical imaging lens group is used to magnify and project the scanning surface corresponding to the light emitted by the fiber optic scanner.

[0019] The fiber optic scanner includes an actuator and an optical fiber fixed to the actuator. The portion of the optical fiber extending beyond the actuator forms an optical fiber cantilever, which performs two-dimensional scanning under the drive of the actuator.

[0020] This application embodiment also provides a near-eye display device, which is used as a head-mounted augmented reality device, and includes at least a near-eye display module and a scanning display device according to the above description, wherein the scanning display device is disposed in the near-eye display module.

[0021] This application embodiment also provides a near-eye display device, which is used as a head-mounted virtual reality device and includes at least a near-eye display module and a scanning display device according to the above description, wherein the scanning display device is disposed in the near-eye display module.

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

[0023] In this embodiment, by reasonably optimizing the focal length of the five coaxial lenses of 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. Thus, clear imaging of the image surface can be achieved while improving the field of view. At the same time, the overall structure of the optical imaging lens group is made more compact by configuring a reasonable number of lenses, which meets the production needs of miniaturized lens products.

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

[0025] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the technical solutions of this application. The objectives and other advantages of this application may be realized and obtained by means of the structures and / or processes particularly pointed out in the description, claims and drawings. Attached Figure Description

[0026] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to 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 an embodiment of the present application;

[0029] Figure 2b is a schematic diagram of a 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 an embodiment of the present application;

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

[0031] Figure 4 is an MTF curve diagram of the optical imaging lens group in the embodiment one of the present application;

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

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

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

[0035] Figure 8 is an MTF curve diagram of the optical imaging lens group in the embodiment two of the present application;

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

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

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

[0039] Figure 12 is an MTF curve diagram of the optical imaging lens group in the embodiment three of the present application;

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

[0041] Figure 14 is a sagittal chromatic aberration diagram of the optical imaging lens group in the embodiment three of the present application.

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

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

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

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

[0046] Figure: 100 - processor; 110 - laser group; 120 - optical fiber scanning module; 130 - transmission optical fiber; 140 - light source modulation circuit; 150 - scanning driving circuit; 160 - beam combining unit; 121 - scanning actuator; 121a - slow axis; 121b - fast axis; 122 - optical fiber cantilever; 123 - lens group; 124 - scanner package shell; 125 - fixing member; 230 - scanning curved surface; 240 - imaging plane; 11 - first lens; 12 - second lens; 13 - third lens; 14 - fourth lens; 15 - fifth lens; 01 - diaphragm; 02 - scanning curved surface; 31 - first lens; 32 - second lens; 33 - third lens; 34 - fourth lens; 35 - fifth 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. DETAILED DESCRIPTION

[0047] The present application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related application, and are not a limitation on the application. In addition, it should be noted that only the parts related to the application are shown in the drawings for ease of description.

[0048] Illustrative scanning display system

[0049] For the current scanning display imaging, it can be realized by a digital micromirror device (DMD) or a fiber scanning display (FSD) device. The FSD scheme as a new type of scanning display imaging method realizes the scanning output of an image through a fiber scanner. In order to enable those skilled in the art to clearly understand the present application scheme, the brief principle of fiber scanning imaging and the corresponding system are described below.

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

[0051] The processor 100, the laser group 110, the optical fiber scanning module 120, the transmission optical fiber 130, the light source modulation circuit 140, the scanning driving circuit 150 and the 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 function and image processing function, which is not specifically limited 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 contains multiple monochromatic lasers, which respectively emit light beams of different colors. As can be seen from FIG. 1, the laser group can specifically use red (R), green (G) and blue (B) lasers. The light beams emitted by each laser in the laser group 110 are combined into a 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 driving circuit 150 to drive the optical fiber scanner in the optical fiber scanning module 120 to scan, so as to scan and output the light beam transmitted in the transmission optical fiber 130.

[0055] The light beam scanned and output by the optical fiber scanner acts on a pixel point position on the medium surface and forms a light spot on the pixel point position, thereby realizing the scanning of the pixel point position. Under the driving of the optical fiber scanner, the output end of the transmission optical fiber 130 scans according to a certain scanning track, so as to move the light beam to the corresponding pixel point position. In the actual scanning process, the light beam output by the transmission optical fiber 130 will form a light spot with corresponding image information (such as color, gray scale or brightness) at each pixel point position. In a frame of time, the light beam traverses each pixel point position at a high enough speed to complete the scanning of a frame of image. Since the human eye has the characteristic of "visual residue" when observing things, the human eye cannot perceive the movement of the light beam on each pixel point position, but sees a complete image.

[0056] Continuing to refer to Figure 1bThe 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.

[0057] 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.

[0058] 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 2a The lens group 123 shown serves 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 practical applications, the direction of light transmission is from the scanning surface 230 to the imaging plane 240). Therefore, the side of the optical imaging lens group corresponding to the imaging plane 240 is referred to as the first side, and the side of the optical imaging lens group corresponding to the scanning surface 230 is referred to as the second side. In the following description, "first side" and "second side" will be used as references to describe the embodiment of the optical imaging lens group. Furthermore, in the description of the subsequent embodiments, 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.

[0059] It is further needed to be explained that in the field of projection, 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., and the image corresponding to the second side is a curved surface image, i.e., a scanning surface in an arc shape scanned by a fiber scanner or emitted by other image sources; in the field of photography, the light path is opposite to that in the field of projection, and the first side generally corresponds to an object side surface for collecting image information, and the second side generally corresponds to an image side surface for collecting an image.

[0060] Optical imaging lens

[0061] The optical imaging lens group in the embodiment of the present application at least includes: first lens, second lens, third lens, fourth lens and fifth lens arranged in sequence on the same optical axis from the first side to the second side, a total of five lenses. It is needed to be explained that the focal lengths of the first lens to the fifth lens in the embodiment of the present application are negative, negative, positive, negative and positive respectively. It is needed to be explained that by reasonably optimizing the positive and negative of the focal lengths of the five on-axis 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, so that clear imaging of the curved surface on the image side can be realized on the basis of improving the field of view. In addition, it is needed to be emphasized that the focal length of the fifth lens is set to be positive, which can strengthen the convergence ability of the curved surface image to balance the aberration.

[0062] Further specifically preferably, the various lenses satisfy the following relationship: -4.76≤f1 / f≤-2.66, -1.26≤f2 / f≤-2.24, 0.39≤f3 / f≤0.43, -0.7≤f4 / f≤-0.3 and 0.39≤f5 / f≤0.59; 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 group (which can also be understood as the equivalent focal length of the optical imaging lens group). It is needed to be explained that by more specifically limiting the focal length of each lens, the optical power of the system is more reasonably dispersed and configured, and the correction of various aberrations is further strengthened, thereby improving the field of view and the imaging quality. In addition, if the position of the lens focal length in the region 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 is needed to be emphasized that before the present application is created, the existing optical imaging lens group for projection display cannot balance the imaging quality and large field of view, i.e., the field of view 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. The present application achieves high-quality imaging output while improving the field of view and being small in size by controlling the combination of the focal lengths and surface structures of the five lenses.

[0063] 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, and is not limited here.

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

[0065] 1.7≤n1≤1.73, 1.67≤n2≤1.76, 1.56≤n3≤1.61, 1.75≤n4≤1.76, 1.62≤n5≤1.63; 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 1.7 or 1.71 or 1.73, n2 is 1.67 or 1.75 or 1.76, n3 is 1.56 or 1.60 or 1.61, n4 is 1.75 or 1.76, and n5 is 1.62 or 1.63. 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 a large field of view.

[0066] Further optionally, in order to better ensure the imaging quality, the embodiments of the present application also specifically prefer to limit the dispersion coefficients of the five lenses, and the dispersion coefficients of the various lenses satisfy: 28.7≤v1≤39.1, 27.6≤v2≤33.7, 60.7≤v3≤64, 27.6≤v4≤28.6, and 58≤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. Specifically, the Abbe number of the first lens is limited to 28.7 or 31.1 or 39.1, the Abbe number of the second lens is limited to 27.6 or 29.8 or 33.7, the Abbe number of the third lens is limited to 60.7 or 61.6 or 64, the Abbe number of the fourth lens is limited to 27.6 or 28.6, and the Abbe number of the fifth lens is limited to 58 or 60.3. It should be noted that in other embodiments of the present application, the Abbe number of the five lenses is not limited to the above, but can also be other dispersion coefficients that can ensure good matching relationship of the five lenses, thereby ensuring the final imaging quality.

[0067] Further optionally, in a possible implementation, the first side surface of the first lens is concave or 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 concave; the first side surface and the second side surface of the third lens are both convex; the first side surface of the fourth lens is concave at the vicinity of the optical axis, the second side surface of the fourth lens is convex; the first side surface of the fifth lens is convex, the second side surface of the fifth lens is concave at the vicinity of the optical axis. It should be noted that by limiting the surface shape structure of the side surface of the above lens, 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 of the lens is convex, which means that the first side surface forms a convex shape towards the first side direction of the optical imaging lens; the first side surface is concave, which means that the first side surface forms a concave shape towards the first side direction of the optical imaging lens; the second side surface is convex, which means that the second side surface forms a convex shape towards the second side direction of the optical imaging lens; the second side surface is concave, which means that the second side surface forms a concave shape towards the second side direction of the optical imaging lens. It should be emphasized that in other embodiments of the present application, the surface shape structure of all lenses is not limited as in the present embodiment, but only the surface shape structure of at least one lens can be limited, such as limiting the surface shape structure of the first side surface and the second side surface of the fifth lens, and the surface shape structure of other lenses is not limited.

[0068] Further, in some embodiments, the surface shape of the lens is not entirely concave or convex, and the surface shape of the lens can be a composite curved surface, or the edge part is not curved while the part near the optical axis is curved. In particular, optionally, when the lens surface is convex and the position of the convex surface is not limited, the convex surface can be located near the optical axis of the lens surface. Similarly, when the lens surface is concave and the position of the concave surface is not limited, the concave surface can be located near the optical axis of the lens surface.

[0069] Further optionally, in a possible implementation, the first side surface and the second side surface of the first lens to the fifth lens are all aspherical surface shape structures. It should be noted that by limiting the surface shape structure of the first lens to the fifth lens to be aspherical surface shape structure, more control variables can be obtained to reduce aberration and reasonably reduce the number of lenses, so as to improve the image display quality and help the miniaturization or micro-miniaturization of the optical imaging lens. In addition, the first side surface and the second side surface of the above lens are both aspherical surface shape structures, which can be understood as that the entire or part of the optical effective area of the lens surface is aspherical.

[0070] Further optionally, in a possible implementation, the first lens to the fifth lens are 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, and compared with the glass material, the cost of the plastic material lens is one-twentieth to one-tenth of the cost of the glass material, so it is very beneficial to low-cost mass production. In addition, the plastic material lens can usually be injection molded, which has low processing difficulty and can be easily processed into various profile structures that meet the aspheric surface. At the same time, the plastic material can also reduce the weight of the lens as a whole, which is beneficial to the 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 characteristics of high temperature resistance, ultraviolet resistance and acid and alkali resistance of glass, the service life and performance stability of the lens group have strong advantages. It should be emphasized that in other embodiments of the present application, the plastic and glass materials provided in the embodiments of the present application are not limited to the two materials, and other materials that can be used to make lenses can also be used.

[0071] 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 the lenses 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.

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

[0073] The plurality of lenses in the optical imaging lens group 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 group corresponds to the curved image, that is, the second side of the optical imaging lens group. The entrance pupil position of the optical imaging lens group corresponds to the flat image, that is, the first side of the optical imaging lens group. It should be noted that please refer to Figures 1a-2b Figure 2b For example, the optical imaging lens group contains 6 lenses), the lens surface close to the exit pupil position and opposite in the plurality of lenses (that is, 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, and the exit pupil distance is 1.5-6.0mm, preferably 2-3.5mm. It should be noted that by limiting the lens surface structure close to the curved image in the plurality of coaxial lenses of the optical imaging lens group and the corresponding exit pupil distance, it can be matched with the corresponding curved scanning image, so as to realize clear imaging from the curved image to the flat image.

[0074] In addition, it should be further explained that please continue to refer to​Figure 2b :

[0075] Entrance pupil: the entrance pupil is the effective aperture of the incident light beam, is the image of the aperture stop on the front optical system, is the conjugate 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 of the aperture stop on the front optical system, the calculation of the entrance pupil position is to regard the center of the aperture stop as an object point, to carry out ray tracing to the front optical system, to obtain the intersection coordinates of the point on the optical axis, and usually to take the distance from the first lens surface as the entrance pupil distance.

[0077] Exit pupil: the image of 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 of the aperture stop on the rear optical system, the calculation of the exit pupil position is to regard the center of the aperture stop as an object point, to carry out ray tracing to the rear optical system, to obtain the intersection coordinates of the point on the optical axis, and usually to take the distance from the last lens surface as the exit pupil distance.

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

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

[0081] Example One

[0082] Figure 3 A structural schematic diagram of an optical imaging lens group provided by the embodiment of the present application. The optical imaging lens group comprises a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, and a fifth lens 15 which are sequentially arranged on the same axis from the first side (that is, the side where the aperture stop 01 in Figure 3 is located) to the second side (that is, the side where the scanning surface 02 in Figure 3 is located).

[0083] In the 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, 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-adhesive lenses.

[0084] The focal lengths of the first lens 11 to the fifth lens 15 from the first side to the second side are negative, negative, positive, negative, and positive in sequence.

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

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

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

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

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

[0090] In the embodiment, the focal lengths of the first lens 11 to the fifth lens 15 in the optical imaging lens group satisfy the following relationship:

[0091] f1 / f is -4.21, f2 / f is -1.26, f3 / f is 0.39, f4 / f is -0.70, and f5 / f is 0.59; 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 group.

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

[0093] n1 is 1.7, n2 is 1.76, n3 is 1.6, n4 is 1.75, and n5 is 1.62. Wherein n1-n5 represent the refractive indices of the first lens 11 to the sixth lens 15 respectively; the Abbe number of the first lens is 39.1, the Abbe number of the second lens is 27.6, the Abbe number of the third lens is 61.6, the Abbe number of the fourth lens is 28.6, and the Abbe number of the fifth lens is 60.3.

[0094] The optical imaging lens group provided by the embodiment one has an equivalent focal length of 2.60mm, an aperture value of 1.30, 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 parameter, refractive index, and dispersion coefficient of each lens in the imaging of the scanning curved surface 02 are shown in Table 1:

[0095] Table 1 Structure parameters of the optical imaging lens group in the embodiment one

[0096] Surface Lens Number Surface Shape 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 1.94 0.82 1.7 39.1 3 Aspheric 1.28 0.70 4 Second Lens 12 Aspheric 1.22 0.98 1.76 27.6 5 Aspheric 0.54 0.15 6 Third Lens 13 Aspheric 0.64 1.35 1.6 61.6 7 Aspheric -2.76 0.18 8 Fourth Lens 14 Aspheric -0.70 1.01 1.75 28.6 9 Aspheric -2.30 0.10 10 Fifth Lens 15 Aspheric 0.70 1.14 1.62 60.3 11 Aspheric 1.05 0.50 12 Scanning Surface 02 Spherical 2

[0097] It is to be noted that Table 1 is the detailed structure data of the optical imaging lens group of Example 1, 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.

[0098] Further, the aspheric conic coefficients of the surfaces corresponding to the first lens 11 to the fifth lens 15 are shown in Table 2 as follows:

[0099] Table 2: Aspheric conic coefficients of the surfaces of different lenses in Example 1

[0100] Surface K A4 A6 A8 2 -4.93E+00 6.53E-02 -2.44E-02 9.85E-03 3 -4.30E+00 8.32E-02 -8.97E-02 4.58E-02 4 -2.30E+00 -1.04E-01 4.74E-02 -6.00E-02 5 -3.34E+00 -3.60E-02 3.79E-02 -1.51E-02 6 -3.51E+00 -1.36E-01 9.60E-02 -2.25E-02 7 -9.70E+01 -9.95E-02 1.76E-02 -6.99E-03 8 -6.18E+00 1.85E-01 -4.39E-02 1.54E-03 9 -1.96E+01 -5.21E-02 1.41E-01 -1.32E-03 10 -1.40E+00 -4.44E-02 9.59E-02 -2.43E-02 11 -3.33E+00 -2.08E-01 -1.06E-01 1.58E-01

[0101] Table 2 is the aspheric coefficient data in Example 1, 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.

[0102] Further, it is tested that when the image light corresponding to the scanning surface of the optical fiber scanner is projected by using the above optical imaging lens group, the modulation transfer function (MTF) 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 6 ; 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.

[0103] It can be observed from Figures 4-6 that the imaging resolution of the optical imaging lens group of Example 1 is good in the full field of view, 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.

[0104] 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 the optical fiber scanner) can be imaged on a plane to realize clear imaging.

[0105] Example Two

[0106] Figure 7 A structure diagram of an optical imaging lens group provided by the embodiment of the present application. The optical imaging lens group includes a first side (that is, a side where the diaphragm 03 in Figure 7 is located) to a second side (that is,Figure 7 The first lens 31, the second lens 32, the third lens 33, the fourth lens 34 and the fifth lens 35 are sequentially arranged on the same axis of the scanning surface 04.

[0107] In the present embodiment, there is a gap between 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, 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.

[0108] The focal length of the first lens 31 to the fifth lens 35 from the first side to the second side is negative, negative, positive, negative 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] The first side surface of the second lens 32 is a convex surface, and the second side surface is a concave surface.

[0111] The first side surface and the second side surface of the third lens 33 are both convex surfaces.

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

[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 the present embodiment, the focal length of the first lens 31 to the fifth lens 35 in the optical imaging lens group satisfies the following relationship:

[0115] f1 / f is -2.66, f2 / f is -2.24, f3 / f is 0.40, f4 / f is -0.45 and f5 / f is 0.50; 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 group.

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

[0117] n1 is 1.71, n2 is 1.75, n3 is 1.61, n4 is 1.75 and n5 is 1.62; wherein n1-n5 represent the refractive index of the first lens 31 to the fifth lens 35 respectively; the Abbe number of the first lens is 31.1, the Abbe number of the second lens is 29.8, the Abbe number of the third lens is 60.7, the Abbe number of the fourth lens is 27.6 and the Abbe number of the fifth lens is 60.3.

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

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

[0120] Surface Lens Number Surface Shape 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 2.85 1.10 1.71 31.1 3 Aspheric 1.51 0.14 4 Second Lens 32 Aspheric 0.95 0.78 1.75 29.8 5 Aspheric 0.51 0.16 6 Third Lens 33 Aspheric 0.74 1.28 1.61 60.7 7 Aspheric -1.43 0.35 8 Fourth Lens 34 Aspheric -0.43 0.85 1.75 27.6 9 Aspheric -1.58 0.10 10 Fifth Lens 35 Aspheric 0.69 1.22 1.62 60.3 11 Aspheric 1.59 0.50 12 Scanning Surface 04 Spherical 2

[0121] 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 radius of curvature, thickness, and focal length are millimeters, and surfaces 0-12 represent the surfaces from the first side to the second side in sequence; the optical surface with a radius of curvature of "infinity" in the imaging plane refers to a plane.

[0122] Further, the aspheric conic coefficients of the surfaces corresponding to the first lens 31 to the fifth lens 35 are shown in Table 4:

[0123] Table 4 Aspheric conic coefficient data of different lens surfaces in the second embodiment

[0124] Surface K A4 A6 A8 2 -5.74E+00 5.44E-02 -1.22E-02 3.78E-03 3 -8.41E+00 9.64E-02 -4.95E-02 -6.39E-03 4 -2.89E+00 -6.44E-02 3.00E-02 -7.63E-02 5 -2.60E+00 6.17E-02 -4.54E-02 -4.02E-02 6 -3.58E+00 -5.52E-03 1.45E-01 -8.08E-02 7 -6.93E+00 -1.09E-01 2.45E-02 4.77E-02 8 -2.78E+00 -1.26E-01 3.74E-02 2.86E-02 9 -1.04E+01 -1.91E-01 8.46E-02 -1.20E-02 10 -8.13E-01 -3.22E-01 1.98E-01 -1.60E-01 11 -1.54E+01 5.01E-01 -1.75E+00 1.27E+00

[0125] Table 4 is the aspheric coefficient data in the second embodiment, 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.

[0126] Further, when the image light corresponding to the scanning surface is projected using the above optical imaging lens, 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 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.

[0127] As can be seen from Figures 8-10 , the optical imaging lens in the second embodiment has good imaging resolution in the full field of view, small optical system distortion and chromatic aberration, and therefore the optical imaging lens can clearly image the scanning surface image of the optical fiber scanner, and has good imaging effect.

[0128] Of course, in practical 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, i.e., the curved image scanned by the image source (such as a fiber scanner) can be imaged on a plane to achieve clear imaging.

[0129] Example Three

[0130] Figure 11 A structural schematic diagram of an optical imaging lens group provided by an embodiment of the present application is shown in FIG. 1. The optical imaging lens group includes first lens 51, second lens 52, third lens 53, fourth lens 54, and fifth lens 55 arranged in sequence on the same optical axis from the first side (i.e., the side on which diaphragm 05 in FIG. 1 is located) to the second side (i.e., the side on which scanning curved surface 06 in FIG. 1 is located). Figure 11 Figure 11

[0131] In this embodiment, each two adjacent lenses among first lens 51, second lens 52, third lens 53, fourth lens 54, and fifth lens 55 have a gap therebetween, and first lens 51, second lens 52, third lens 53, fourth lens 54, and fifth lens 55 are five single non-adhesive lenses.

[0132] The focal lengths of first lens 51 to fifth lens 55 from the first side to the second side are negative, negative, positive, negative, and positive in sequence.

[0133] The first side surface and the second side surface of first lens 51 are both concave.

[0134] The first side surface of second lens 52 is convex, and the second side surface is concave near the optical axis.

[0135] The first side surface of third lens 53 is convex, and the second side surface is convex near the optical axis.

[0136] The first side surface of fourth lens 54 is concave near the optical axis, and the second side surface is convex.

[0137] The first side surface of fifth lens 55 is convex, and the second side surface is concave near the optical axis.

[0138] In this embodiment, the focal lengths of first lens 51 to fifth lens 55 in the optical imaging lens group satisfy the following relationship:

[0139] ​​f1 / f is -4.76, f2 / f is -1.97, f3 / f is 0.43, f4 / f is -0.31, and f5 / f is 0.39; 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.

[0140] The refractive indices and dispersion coefficients of the first lens 51 to the fifth lens 55 in the optical imaging lens satisfy the following conditions respectively:

[0141] n1 is 1.73, n2 is 1.67, n3 is 1.56, n4 is 1.76, and n5 is 1.63. 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 28.7, the Abbe number of the second lens is 33.7, the Abbe number of the third lens is 64, the Abbe number of the fourth lens is 27.6, and the Abbe number of the fifth lens is 58.

[0142] In the optical imaging lens provided by the third embodiment of the present application, the equivalent focal length of the optical imaging lens as a whole is 2.6mm, the aperture value is 1.30, the half field angle is 10 degrees, the scanning radius is 2mm, and the entrance pupil diameter is 2mm. The preferred parameters of the curvature radius, thickness, refractive index and dispersion coefficient of each lens in the imaging of the scanning curved surface 06 are shown in Table 5:

[0143] Table 5 Structure parameters of the optical imaging lens in the third embodiment

[0144] Surface Lens Number Surface Shape 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 -11.37 1.05 1.73 28.7 3 Aspheric 50.51 0.12 4 Second Lens 52 Aspheric 1.20 1.15 1.67 33.7 5 Aspheric 0.55 0.28 6 Third Lens 53 Aspheric 0.68 1.25 1.56 64 7 Aspheric -2.57 0.42 8 Fourth Lens 54 Aspheric -0.40 0.70 1.76 27.6 9 Aspheric -1.99 0.10 10 Fifth Lens 55 Aspheric 0.61 1.18 1.63 58 11 Aspheric 3.62 0.50 12 Scanning Surface 06 Spherical 2

[0145] It should be noted that Table 5 is the detailed structure data of the optical imaging lens in the third embodiment, 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 order; the optical surface with a curvature radius of "infinity" in the imaging plane means a plane.

[0146] Further, the aspheric conic coefficients of the surfaces corresponding to the first lens 51 to the fifth lens 55 are shown in Table 6:

[0147] Table 6 Aspheric conic coefficient data of different lens surfaces in the third embodiment

[0148] Surface K A4 A6 A8 2 -3.92E+02 3.52E-02 -1.87E-02 2.50E-03 3 4.00E+02 8.25E-02 -7.71E-02 1.71E-02 4 -2.70E+00 8.55E-02 -4.54E-02 -2.16E-04 5 -2.85E+00 1.93E-01 -2.23E-01 3.50E-02 6 -2.77E+00 1.23E-01 -8.55E-02 7.54E-04 7 -1.90E+01 4.05E-02 -1.56E-01 1.33E-01 8 -2.81E+00 -1.60E-01 2.46E-01 -1.40E-01 9 1.81E+00 2.18E-02 5.72E-02 1.88E-04 10 -2.56E+00 1.59E-01 -8.02E-02 -2.20E-02 11 -1.25E+01 1.48E-01 -6.25E-01 4.23E-01

[0149] Table 6 is the aspheric coefficient data in the third embodiment, 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.

[0150] Furthermore, tests showed that when the image light corresponding to the scanning surface is projected using the aforementioned optical imaging lens group, its optical transfer function curve is as follows: Figure 12 As shown, the field distortion curve is as follows: Figure 13 As shown, the vertical axis color difference curve is as follows: Figure 14 As shown; among them, the Modulation Transfer Function (MTF) curve represents the overall resolution level of an optical system, the Field Curve Distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the Vertical Chromatic Aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0151] Depend on Figures 12-14 Observations show that the optical imaging lens group in Example 3 has good imaging resolution, small optical system distortion and chromatic aberration across the entire field of view. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber optic scanner and has good imaging effect.

[0152] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element can be set on the second side of the optical imaging lens assembly, and the optical imaging lens assembly can be installed in the housing, so that the curved image formed by the image source (such as a fiber optic scanner) can be imaged on a plane to achieve clear imaging.

[0153] Example Four

[0154] Figure 15 This is a schematic diagram of an optical imaging lens assembly provided in an embodiment of the present invention. The optical imaging lens assembly includes a first side (i.e., Figure 15 From the side where aperture 07 is located to the second side (that is, Figure 15 The first lens 71, second lens 72, third lens 73, fourth lens 74, fifth lens 75, and sixth lens 76 are arranged sequentially along the common optical axis on the side where the scanning surface 08 is located. It should be noted that the first lens 71 provided in this embodiment is equivalent to an additional lens, and the positive and negative focal lengths of the second lens 72, third lens 73, fourth lens 74, fifth lens 75, and sixth lens 76 correspond to the positive and negative focal lengths of the five lenses defined in the claims. The terms "first," "second," etc., in the embodiments do not indicate the importance or order of the lenses, but are simply used to distinguish different components.

[0155] In this embodiment, there is a gap between each pair of adjacent lenses in 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.

[0156] The focal lengths of the first lens 71 to the sixth lens 76 from the first side to the second side are positive, negative, negative, positive, negative and positive in sequence.

[0157] The first side surface of the first lens 71 is a concave surface, and the second side surface is a convex surface.

[0158] The first side surface and the second side surface of the second lens 72 are both concave surfaces.

[0159] The first side surface of the third lens 73 is a convex surface, and the second side surface is a concave surface at the vicinity of the optical axis.

[0160] The first side surface and the second side surface of the fourth lens 74 are both convex surfaces.

[0161] The first side surface of the fifth lens 75 is a concave surface at the vicinity of the optical axis, and the second side surface is a convex surface.

[0162] The first side surface of the sixth lens 76 is a convex surface, and the second side surface is a concave surface at the vicinity of the optical axis.

[0163] In the present embodiment, the focal lengths of the first lens 71 to the sixth lens 76 in the optical imaging lens satisfy the following relationship:

[0164] f1 / f is 10.18, f2 / f is -4.11, f3 / f is -1.43, f4 / f is 0.42, f5 / f is -0.37 and f6 / f is 0.43; 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.

[0165] The refractive indices and the dispersion coefficients of the first lens 71 to the sixth lens 76 in the optical imaging lens satisfy the following conditions respectively:

[0166] n1 is 1.52, n2 is 1.73, n3 is 1.71, n4 is 1.57, n5 is 1.69 and n6 is 1.62. 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 66.8, the Abbe number of the second lens is 29.2, the Abbe number of the third lens is 29.6, the Abbe number of the fourth lens is 63.5, the Abbe number of the fifth lens is 30.7 and the Abbe number of the sixth lens is 60.3.

[0167] The optical imaging lens provided in the fourth embodiment has an equivalent focal length of 2.6 mm, an aperture value of 1.30, a half field angle of 10 degrees, a scanning radius of 2 mm, and an entrance pupil diameter of 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:

[0168] Table 7 Structure parameters of the optical imaging lens in the fourth embodiment

[0169] Surface Lens Number Surface Shape 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 -2.67 0.83 1.52 66.8 3 Spherical -2.48 0.10 4 Second Lens 72 Aspheric -10.97 0.84 1.73 29.2 5 Aspheric 29.48 0.10 6 Third Lens 73 Aspheric 1.22 1.08 1.71 29.6 7 Aspheric 0.53 0.26 8 Fourth Lens 74 Aspheric 0.64 1.30 1.57 63.5 9 Aspheric -4.05 0.45 10 Fifth Lens 75 Aspheric -0.43 0.71 1.69 30.7 11 Aspheric -2.10 0.18 12 Sixth Lens 76 Aspheric 0.66 1.15 1.62 60.3 13 Aspheric 5.15 0.50 14 Scanning Surface 08 Spherical 2

[0170] It should be noted that Table 7 is the detailed structure data of the optical imaging lens in the fourth embodiment, wherein the units of the curvature radius, thickness, and focal length are millimeters, and the surfaces 0-14 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 refers to a plane.

[0171] Further, the aspheric conic coefficients of the surfaces corresponding to the first lens 71 to the sixth lens 76 are shown in Table 8:

[0172] Table 8 Aspheric conic coefficient data of different lens surfaces in the fourth embodiment

[0173] Surface K A4 A6 A8 4 -3.68E+02 3.49E-02 -1.91E-02 1.63E-03 5 2.68E+02 8.70E-02 -7.57E-02 1.49E-02 6 -2.90E+00 8.61E-02 -4.40E-02 -6.56E-04 7 -2.79E+00 1.91E-01 -2.22E-01 3.54E-02 8 -2.76E+00 1.12E-01 -9.52E-02 -5.06E-03 9 2.22E+00 8.46E-03 -1.64E-01 1.32E-01 10 -2.54E+00 -2.12E-01 2.64E-01 -1.14E-01 11 1.84E+00 7.12E-03 4.33E-02 5.10E-03 12 -2.36E+00 1.23E-01 -4.25E-02 -8.00E-02 13 -2.83E+01 1.17E-01 -6.06E-01 3.85E-01

[0174] Table 8 is the aspheric coefficient data in the fourth embodiment, 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.

[0175] Further, when the image light corresponding to the scanning surface is projected by using the above optical imaging lens, 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 18 ; 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 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.

[0176] As can be seen from Figures 16-18 , the optical imaging lens in the fourth embodiment has good imaging resolution in the full field of view, small optical system distortion and chromatic aberration, and therefore can clearly image the scanning surface image of the optical fiber scanner, and has good imaging effect.

[0177] Of course, in practical 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, i.e., the curved image formed by the image source (such as a fiber scanner) can be imaged on a plane to achieve clear imaging.

[0178] Scanning display device

[0179] The aforementioned 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 As shown, 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 foregoing Figure 1a 、 1b The corresponding content will not be described in detail here.

[0180] Near-eye display device

[0181] In the present application, the scanning display device can be further applied to a near-eye display device, and can be combined with a near-eye display module to form a near-eye display device in the embodiments of the present application, and can be used as a head-mounted AR device (such as AR glasses). The scanning display device is arranged in the near-eye display module.

[0182] The near-eye display module can include a light source, a processing control circuit, a wearable frame structure, a waveguide, etc. The image light beam output by the light source enters the scanning display device, is scanned by the fiber scanner in the scanning display device, and is output to the optical display lens group. The scanning surface (which can refer to the scanning surface 02 in Figure 3 and the corresponding scanning surface 230 in Figure 2a ) of the fiber scanner is converted into an imaging plane (which can refer to the imaging plane 240 in Figure 2a ) after the optical display lens group, and the imaging plane is coupled into the waveguide as an entrance pupil surface of the waveguide, and then expanded and coupled out through the waveguide to enter the human eye.

[0183] As another possible implementation, the scanning display device can be further combined with a near-eye display module to form a near-eye display device in the embodiments of the present application, and can be used as a head-mounted VR device (such as a VR helmet / glasses). The scanning display device is arranged in the near-eye display module.

[0184] In the embodiments 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 slowed down, the purpose of correcting various aberrations can be achieved, and clear imaging of the image surface can be achieved on the basis of improving the field of view; 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 five coaxial lenses to be aspherical surface structures, the imaging quality is further improved, and the overall structure of the optical imaging lens group is more compact, meeting the production needs of miniaturization of the lens product.

[0185] The above is only the preferred embodiment of the present application, and each embodiment is only used to illustrate the technical solution of the present application, but not to limit the present application. Any technical solution obtained by logical analysis, reasoning or effective experiment according to the concept of the present application should be within the scope of the present application.

[0186] Each embodiment in the present application is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other. Each embodiment mainly describes the difference from other embodiments.

[0187] The expressions "first", "second", "the first" or "the second" used in various embodiments of the present disclosure can modify various components regardless of order and / or importance, but these expressions do not limit the corresponding components. The above expressions are only configured for the purpose of distinguishing the elements 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 assembly, characterized in that, The optical imaging lens group includes at least a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged coaxially from the first side to the second side. The focal lengths of the first lens to the fifth lens are negative, negative, positive, negative, and positive, respectively. Each lens also satisfies the following relationships: -4.76≤f1 / f≤-2.66, -1.26≤f2 / f≤-2.24, 0.39≤f3 / f≤0.43, -0.7≤f4 / f≤-0.3, and 0.39≤f5 / f≤0.

59. 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 group. The exit pupil distance of the optical imaging lens group is 1.5-6.0 mm.

2. The optical imaging lens assembly as described in claim 1, characterized in that, The second side surface of the fifth lens is concave near the optical axis.

3. The optical imaging lens assembly as described in claim 2, characterized in that, The various lenses also satisfy the following relationships: 1.7≤n1≤1.73, 1.67≤n2≤1.76, 1.56≤n3≤1.61, 1.75≤n4≤1.76, 1.62≤n5≤1.63; 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 the following: 28.7≤v1≤39.1, 27.6≤v2≤33.7, 60.7≤v3≤64, 27.6≤v4≤28.6, 58≤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 assembly as described in claim 3, characterized in that, The n1 is 1.7, 1.71, or 1.73; the n2 is 1.67, 1.75, or 1.76; the n3 is 1.56, 1.60, or 1.61; the n4 is 1.75 or 1.76; and the n5 is 1.62 or 1.

63. The dispersion coefficients of the various lenses satisfy the following conditions: the Abbe number of the first lens is 28.7, 31.1, or 39.1; the Abbe number of the second lens is 27.6, 29.8, or 33.7; the Abbe number of the third lens is 60.7, 61.6, or 64; the Abbe number of the fourth lens is 27.6 or 28.6; and the Abbe number of the fifth lens is 58 or 60.

3.

5. The optical imaging lens assembly as described in claim 2, characterized in that, The first side surface of the fifth lens is convex; the first side surface of the fourth lens is concave near the optical axis, and the second side surface of the fourth lens is convex.

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

7. The optical imaging lens assembly as described in claim 6, characterized in that, The first side surface of the second lens is convex, and the second side surface of the second lens is concave; both the first side surface and the second side surface of the third lens are convex. The first and 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, The invention includes a fiber optic scanner and an optical imaging lens group according to any one of claims 1 to 7, wherein the fiber optic scanner is used to scan and emit light to display an image, and the optical imaging lens group is used to magnify and project the scanning surface corresponding to the light emitted by the fiber optic scanner. The fiber optic scanner includes an actuator and an optical fiber fixed to the actuator. The portion of the optical fiber extending beyond the actuator forms an optical fiber cantilever, which 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 includes at least a near-eye display module and a scanning display device according to claim 8, wherein 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 includes at least a near-eye display module and a scanning display device according to claim 8, wherein the scanning display device is disposed in the near-eye display module.

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