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 like, which limits the application of scanning display imaging in the market, especially when it is applied to the near-eye display, 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 present application aims 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 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 along the same optical axis, wherein the focal lengths of the first lens to the fifth lens are positive, negative, positive, positive and negative respectively.

[0006] Optionally, the various lenses satisfy the following relationship: 0.3≤|f2 / f|≤1 and 0.52≤|f5 / f|≤1.7, wherein f2 is the focal length of the second 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: 3≤f1 / f≤7, 0.48≤f3 / f≤0.53 and 2.82≤f4 / f≤32.84, wherein f1 is the focal length of the first lens, f3 is the focal length of the third 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 relationships: 1.432 < n1 < 1.832, 1.432 < n2 < 1.832, 1.335 < n3 < 1.735, 1.335 < n4 < 1.735, 1.432 < n5 < 1.832; 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] Optionally, n1 is 1.632, n2 is 1.632, n3 is 1.535, n4 is 1.535, and n5 is 1.632.

[0011] The various lenses satisfy the following relationships: 1.432 < n1 < 1.832, 1.432 < n2 < 1.832, 1.335 < n3 < 1.735, 1.335 < n4 < 1.735, 1.432 < n5 < 1.832; 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.

[0012] Optionally, 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.

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

[0014] Optionally, the first side surface and the second side surface of the second lens are both concave, and the first side surface and the second side surface of the third lens are both convex.

[0015] The first side surface and the second side surface of the first lens to the fifth lens are both aspherical surface structures.

[0016] 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.

[0017] The application also provides a scanning display device, which comprises a fiber scanner and the optical imaging lens as described above, the fiber scanner is used to scan and emit light of an image to be displayed, and the optical imaging lens is used to magnify and project a scanning surface corresponding to the light emitted by the fiber scanner.

[0018] The fiber scanner comprises an actuator and a fiber fixed on the actuator, a part of the fiber beyond the actuator forms a fiber cantilever, and the fiber cantilever performs two-dimensional scanning under the driving of the actuator.

[0019] The embodiment of the present application also provides a near-eye display device, which is used as a head-mounted augmented reality device and comprises at least a near-eye display module and the scanning display device.

[0020] The embodiment of the present application also provides a near-eye display device, which is used as a head-mounted virtual reality device and comprises at least a near-eye display module and the scanning display device.

[0021] The technical solution in the embodiment of the present application can achieve the following technical effects:

[0022] In the embodiment of the present application, the focal lengths of the five coaxial lenses of the optical imaging lens group are reasonably optimized, so that 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; at the same time, the overall structure of the optical imaging lens group is more compact through the reasonable number of lens combination configurations, and the production demand of miniaturization of the lens product is met.

[0023] Further, by limiting and optimizing the refractive index, dispersion coefficient and surface structure of the five coaxial lenses, the field of view and the imaging quality are further improved.

[0024] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or will be learned by practice of the present application. The objects and other advantages of the present application will be realized and achieved by means of the structures and / or processes particularly pointed out in the description and the claims. BRIEF DESCRIPTION OF DRAWINGS

[0025] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the accompanying drawings:

[0026] Figure 1a 、 1b FIG. 1 is a structural schematic diagram of an illustrative scanning display system;

[0027] Figure 2a FIG. 2 is a schematic diagram of scanning output of a fiber scanner provided in the embodiment of the present application;

[0028] Figure 2b FIG. 3 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 in the embodiment of the present application;

[0029] Figure 3is a structural schematic diagram of an optical imaging lens provided by Embodiment One of the present application;

[0030] Figure 4 is an MTF curve diagram of the optical imaging lens in Embodiment One of the present application;

[0031] Figure 5 is a field curvature distortion curve diagram of the optical imaging lens in Embodiment One of the present application;

[0032] Figure 6 is a sagittal chromatic aberration diagram of the optical imaging lens in Embodiment One of the present application.

[0033] Figure 7 is a structural schematic diagram of an optical imaging lens provided by Embodiment Two of the present application;

[0034] Figure 8 is an MTF curve diagram of the optical imaging lens in Embodiment Two of the present application;

[0035] Figure 9 is a field curvature distortion curve diagram of the optical imaging lens in Embodiment Two of the present application;

[0036] Figure 10 is a sagittal chromatic aberration diagram of the optical imaging lens in Embodiment Two of the present application.

[0037] Figure 11 is a structural schematic diagram of an optical imaging lens provided by Embodiment Three of the present application;

[0038] Figure 12 is an MTF curve diagram of the optical imaging lens in Embodiment Three of the present application;

[0039] Figure 13 is a field curvature distortion curve diagram of the optical imaging lens in Embodiment Three of the present application;

[0040] Figure 14 is a sagittal chromatic aberration diagram of the optical imaging lens in Embodiment Three of the present application.

[0041] Figure 15 is a structural schematic diagram of an optical imaging lens provided by Embodiment Four of the present application;

[0042] Figure 16 is an MTF curve diagram of the optical imaging lens in Embodiment Four of the present application;

[0043] Figure 17 is a field curvature distortion curve diagram of the optical imaging lens in Embodiment Four of the present application;

[0044] Figure 18 is a sagittal chromatic aberration diagram of the optical imaging lens in Embodiment Four of the present application.

[0045] Figure 19 is a structural schematic diagram of an optical imaging lens provided in Embodiment Five of the present application;

[0046] Figure 20 is an MTF curve diagram of the optical imaging lens in Embodiment Five of the present application;

[0047] Figure 21 is a field curvature distortion curve diagram of the optical imaging lens in Embodiment Five of the present application;

[0048] Figure 22 is an axial chromatic aberration diagram of the optical imaging lens in Embodiment Five of the present application.

[0049] 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; 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 DESCRIPTION

[0050] 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, for ease of description, only the parts related to the application are shown in the drawings.

[0051] Illustrative scanning display system

[0052] 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 is a new type of scanning display imaging method, which realizes the scanning output of the image through a fiber scanner. In order to enable those skilled in the art to clearly understand the scheme of the present application, the brief principle and the corresponding system of the fiber scanning imaging are described below.

[0053] As shown in Figure 1a , it is an illustrative scanning display system in the present application, which mainly includes:

[0054] The processor 100, the laser group 110, the fiber scanning module 120, the transmission fiber 130, the light source modulation circuit 140, the scanning driving circuit 150 and the beam combining unit 160. Among them,

[0055] 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.

[0056] 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 fiber 130.

[0057] The processor 100 can also control the scanning driving circuit 150 to drive the fiber scanner in the fiber scanning module 120 to scan, so as to scan and output the light beam transmitted in the transmission fiber 130.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] Optical imaging lens

[0064] 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 positive, negative, positive, 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.

[0065] Further specifically preferably, the various lenses satisfy the following relationships: 3≤f1 / f≤7, 0.3≤|f2 / f|≤1, 0.48≤f3 / f≤0.53, 2.82≤f4 / f≤32.84, and 0.52≤|f5 / f|≤1.7; where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, and f is the focal length of the optical imaging lens (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 region where the lens focal length is located is not defined in the present 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 could not balance the imaging quality and large field of view angle, i.e., the field of view angle was usually improved at the expense of the imaging quality, and it was difficult to ensure the imaging quality while achieving a large field of view angle. However, the present application achieves high-quality imaging output while improving the field of view angle and being compact by controlling the focal length and surface structure of the five lenses.

[0066] 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.

[0067] Further, in a possible implementation, the various lenses further satisfy the following relationships:

[0068] 1.432<n1<1.832, 1.432<n2<1.832, 1.335<n3<1.735, 1.335<n4<1.735, 1.432<n5<1.832; where n1 is the refractive index of the first lens, n2 is the refractive index of the second lens, n3 is the refractive index of the third lens, n4 is the refractive index of the fourth lens, and n5 is the refractive index of the fifth lens. Preferably, the n1 is 1.632, the n2 is 1.632, the n3 is 1.535, the n4 is 1.535, and the n5 is 1.632. 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.

[0069] Further optionally, in order to better ensure the imaging quality, the Abbe number of the first lens is 23.2, the Abbe number of the second lens is 23.2, the Abbe number of the third lens is 55.7, the Abbe number of the fourth lens is 55.7, and the Abbe number of the fifth lens is 23.2. 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, and other dispersion coefficients that can ensure good matching relationship between the five lenses can also be used to ensure the final imaging quality.

[0070] Further optionally, in one possible implementation, the first side surface of the first lens is a concave surface or a convex surface, the second side surface of the first lens is a convex surface, the first side surface and the second side surface of the second lens are both concave surfaces, the first side surface and the second side surface of the third lens are both convex surfaces, the first side surface of the fourth lens is a concave surface near the optical axis, the second side surface of the fourth lens is a convex surface, and the first side surface of the fifth lens is a convex surface and the second side surface of the fifth lens is a concave surface near the optical axis. It should be noted that by limiting the surface shape of the above lenses, the aberration between the lenses can be 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 a convex surface 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 a concave surface 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 a convex surface 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 a concave surface 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 of all lenses is not limited to the above, and the surface shape of at least one lens can also be limited.

[0071] Further, in some embodiments, the surface shape of the lens is not a concave surface or a convex surface throughout the side surface, 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 defined, 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 defined, the concave surface can be located near the optical axis of the lens surface.

[0072] Further optionally, in a possible implementation, the first side surface and the second side surface of the first lens to the fifth lens are both aspherical surface structures. It should be noted that by limiting the surface structure of the first lens to the fifth lens to be aspherical surface structure, more control variables can be obtained to reduce aberration and reasonably reduce the number of lenses, thereby helping to miniaturize or microsize the optical imaging lens group while improving the image display quality. In addition, the first side surface and the second side surface of the lens are both aspherical surface structures, which can be understood as that the entire or part of the optical effective area of the lens surface is aspherical.

[0073] Further optionally, in a possible implementation, the first lens to the fifth lens are both made of plastic or glass. It should be noted that the first lens to the fifth lens made of plastic can effectively reduce the production cost. Compared with glass material, the cost of plastic material lens is one-twentieth to one-tenth of the cost of glass material, which is very beneficial to low-cost mass production. In addition, the plastic material lens can generally be molded by injection molding, which has low processing difficulty and can be easily processed into various profile structures that meet the aspherical surface. Meanwhile, 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 glass material is higher and wider, which has an advantage in correcting lens aberration. The expansion coefficient of glass material is much smaller, which is beneficial to precise assembly. In addition, due to the characteristics of glass such as high temperature resistance, ultraviolet resistance, and acid and alkali resistance, 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 manufacture lenses can also be used.

[0074] 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 help improve the image display quality.

[0075] Further, in some embodiments, the optical imaging lens group in the embodiments of the present application also satisfies the following optical characteristics:

[0076] The plurality of lenses in the optical imaging lens group are arranged on the same optical axis from the entrance pupil position to the exit pupil position. The exit pupil position of the optical imaging lens group corresponds to a curved image, i.e., the second side of the optical imaging lens group. The entrance pupil position of the optical imaging lens group corresponds to a flat image, i.e., the first side of the optical imaging lens group. It should be noted that please refer to Figures 1a to 2b Figure 2b ​For example, in an optical imaging lens group containing 6 lenses, the lens surface opposite to the exit pupil position and close to the exit pupil position (i.e. the lens surface closest to the curved image) is a concave surface, the intersection of the optical axis and the concave surface forms a point of intersection, the distance between the point of intersection and the exit pupil position is the exit pupil distance, the exit pupil distance is 1.5-6.0 mm, preferably, the exit pupil distance is 2-3.5 mm. It should be noted that by limiting the surface structure of the lens close to the curved image in the optical imaging lens group and the corresponding exit pupil distance, the curved image can be matched with the corresponding curved scanning image, so that clear imaging from the curved image to the flat image can be realized.

[0077] In addition, it should be further explained that please continue to refer to Figure 2b :

[0078] Entrance pupil: the entrance pupil is the effective aperture of the incident light beam, the image formed by the aperture stop to the front optical system, the conjugate of the aperture stop in the object space, the entrance pupil corresponds to the exit pupil;

[0079] 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, to perform 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 surface of the first lens as the entrance pupil distance.

[0080] 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;

[0081] 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, to perform 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 surface of the last lens as the exit pupil distance.

[0082] 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.

[0083] Further specifically, as Figure 2b shown, from left to right, i.e. 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).

[0084] Example One

[0085] 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 side (i.e. a side where the aperture 01 in Figure 3 , to a second side (i.e. a side where the aperture 02 in Figure 3The first lens 11, the second lens 12, the third lens 13, the fourth lens 14 and the fifth lens 15 are sequentially arranged on the same optical axis.

[0086] In the embodiment, there is a gap between 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, 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.

[0087] The focal length of the first lens 11 to the fifth lens 15 from the first side to the second side is positive, negative, positive, positive and negative in sequence.

[0088] The first side surface and the second side surface of the first lens 11 are both convex.

[0089] The first side surface of the second lens 12 is concave at the near optical axis, and the second side surface is concave.

[0090] The first side surface and the second side surface of the third lens 13 are both convex.

[0091] The first side surface of the fourth lens 14 is convex at the near optical axis, and the second side surface is convex.

[0092] The first side surface of the fifth lens 15 is convex, and the second side surface is concave at the near optical axis.

[0093] In the embodiment, the focal length of the first lens 11 to the fifth lens 15 in the optical imaging lens group satisfies the following relationship:

[0094] f1 / f is 3.00, f2 / f is -0.46, f3 / f is 0.54, f4 / f is 32.84, and f5 / f is -1.48; 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.

[0095] The refractive index and the dispersion coefficient of the first lens 11 to the fifth lens 15 in the optical imaging lens group satisfy the following conditions respectively:

[0096] n1 is 1.632, n2 is 1.632, n3 is 1.535, n4 is 1.535, and n5 is 1.632. Wherein n1-n5 represent the refractive index of the first lens 11 to the sixth lens 15 respectively; the Abbe number of the first lens is 23.2, the Abbe number of the second lens is 23.2, the Abbe number of the third lens is 55.7, the Abbe number of the fourth lens is 55.7, and the Abbe number of the fifth lens is 23.2.

[0097] The optical imaging lens provided by the embodiment one has an equivalent focal length of 2.57 mm, an aperture value of 1.25, 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 for imaging the scanning surface 02 are shown in Table 1:

[0098] Table 1 Structure parameters of the optical imaging lens in embodiment one

[0099]

[0100]

[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 aspheric conic coefficients of the surfaces corresponding to the first lens 11 to the fifth lens 15 are shown in Table 2:

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

[0104] Surface K A4 A6 A8 2 -3.95E+02 2.98E-02 7.92E-03 -3.95E-03 3 -8.50E+00 4.07E-02 1.10E-02 -4.31E-03 4 -4.17E+00 1.05E-01 -1.18E-01 1.39E-02 5 -7.61E-01 4.02E-02 -6.15E-02 6.04E-03 6 -2.57E+00 -7.43E-02 3.48E-02 -1.22E-02 7 -2.59E+00 5.37E-04 3.80E-03 1.71E-03 8 -5.27E+00 8.41E-02 -4.78E-03 4.36E-04 9 -1.02E+00 8.41E-02 -2.10E-02 3.65E-03 10 -4.10E-02 6.93E-02 -4.67E-02 -8.02E-03 11 1.22E-01 1.01E+00 -4.71E+00 1.28E+00

[0105] Table 2 is the aspheric coefficient data in embodiment one, 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.

[0106] 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 6 ; 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.

[0107] As can be seen from Figures 4-6 , the optical imaging lens in embodiment one 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.

[0108] 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 surface image scanned by the image source (such as a fiber scanner) can be imaged on a plane to achieve clear imaging.

[0109] Example Two

[0110] Figure 7 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 31, second lens 32, third lens 33, fourth lens 34, and fifth lens 35 arranged in sequence on the same optical axis from the first side (i.e., the side on which diaphragm 03 in FIG. 1 is located) to the second side (i.e., the side on which scanning curved surface 04 in FIG. 1 is located). Figure 7 Figure 7

[0111] In this embodiment, each two adjacent lenses among first lens 31, second lens 32, third lens 33, fourth lens 34, and fifth lens 35 have a gap therebetween, and first lens 31, second lens 32, third lens 33, fourth lens 34, and fifth lens 35 are five single non-adhesive lenses.

[0112] The focal lengths of first lens 31 to fifth lens 35 from the first side to the second side are positive, negative, positive, positive, and negative in sequence.

[0113] The first side surface of first lens 31 is a convex surface, and the second side surface is a convex surface near the optical axis.

[0114] The first side surface of second lens 32 is a concave surface near the optical axis, and the second side surface is a concave surface.

[0115] The first side surface of third lens 33 is a convex surface near the optical axis, and the second side surface is a convex surface.

[0116] The first side surface of fourth lens 34 is a concave surface near the optical axis, and the second side surface is a convex surface.

[0117] The first side surface of fifth lens 35 is a convex surface, and the second side surface is a concave surface near the optical axis.

[0118] In this embodiment, the focal lengths of first lens 31 to fifth lens 35 in the optical imaging lens group satisfy the following relationship:

[0119] ​​f1 / f is 3.23, f2 / f is -0.39, f3 / f is 0.53, f4 / f is 3.12, and f5 / f is -1.68; 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.

[0120] 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:

[0121] n1 is 1.632, n2 is 1.632, n3 is 1.535, n4 is 1.535, and n5 is 1.632; 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 23.2, the Abbe number of the second lens is 23.2, the Abbe number of the third lens is 55.7, the Abbe number of the fourth lens is 55.7, and the Abbe number of the fifth lens is 23.2.

[0122] 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 2.65 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 imaging the scanning surface 04 are shown in Table 3:

[0123] Table 3 Structure parameters of the optical imaging lens in the second embodiment

[0124] Surface Lens Number Surface Form Radius of Curvature Thickness / Spacing Material Material Refractive Index Dispersion Coefficient 0 Imaging Plane Plane Infinity Infinity 1 Stop 03 Infinity 1 2 First Lens 31 Asphere 17.65 0.94 Plastic 1.632 23.2 3 Asphere -8.05 2.96 4 Second Lens 32 Asphere -1.25 0.80 Plastic 1.632 23.2 5 Asphere 1.89 0.13 6 Third Lens 33 Asphere 0.87 1.55 Plastic 1.535 55.7 7 Asphere -1.60 0.36 8 Fourth Lens 34 Asphere -1.92 1.35 Plastic 1.535 55.7 9 Asphere -1.64 0.10 10 Fifth Lens 35 Asphere 1.15 1.14 Plastic 1.632 23.2 11 Asphere 0.50 0.50 12 Scanning Surface 04 Sphere 2

[0125] 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.

[0126] Further, the aspheric conic coefficients of the surfaces corresponding to the first lens 31 to the fifth lens 35 are shown in Table 4:

[0127] Table 4 Aspheric conic coefficient data of different lens surfaces in the second embodiment

[0128] Surface K A4 A6 A8 2 1.13E+02 4.17E-02 1.28E-03 7.59E-04 3 -2.03E+01 6.08E-02 4.68E-03 7.94E-03 4 -1.13E+01 1.59E-02 -8.07E-02 3.43E-02 5 2.26E-01 -9.16E-02 -5.18E-02 9.97E-03 6 -3.73E+00 -5.66E-02 4.69E-02 -2.26E-02 7 -2.17E+00 3.34E-02 2.72E-02 -1.27E-02 8 -1.14E+01 1.73E-01 -5.75E-02 2.16E-03 9 -4.79E+00 8.07E-02 -6.21E-02 1.16E-02 10 -1.54E+00 5.09E-02 -5.63E-02 2.40E-02 11 -5.74E-01 -1.56E+00 1.73E+00 -4.17E+00

[0129] 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.

[0130] Further, when the optical imaging lens group is used to project the image light corresponding to the scanning surface, 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.

[0131] It can be observed that the optical imaging lens group of the second embodiment has good imaging resolution, small optical system distortion and small chromatic aberration in the full field of view, and therefore can clearly image the scanning surface image of the fiber scanner, and all have good imaging effects. Figures 8-10 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.

[0132]

[0133] Example Three

[0134] Figure 11 A structural schematic diagram of an optical imaging lens group according to an embodiment of the present application is provided. 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., a side on which the diaphragm 05 in Figure 11 is located) to a second side (i.e., a side on which the scanning curved surface 06 in Figure 11 is located).

[0135] 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.

[0136] The focal lengths of the first lens 51 to the fifth lens 55 from the first side to the second side are positive, negative, positive, positive, and negative in sequence.

[0137] The first side surface of the first lens 51 is a concave surface, and the second side surface is a convex surface.

[0138] The first side surface and the second side surface of the second lens 52 are both concave surfaces.​

[0139] The first side surface and the second side surface of the third lens 53 are both convex.

[0140] The first side surface of the fourth lens 54 is concave at the near optical axis, and the second side surface is convex.

[0141] The first side surface of the fifth lens 55 is convex, and the second side surface is concave at the near optical axis.

[0142] In the embodiment, the focal lengths of the first lens 51 to the fifth lens 55 in the optical imaging lens group satisfy the following relationship:

[0143] f1 / f is 4.33, f2 / f is -0.59, f3 / f is 0.48, f4 / f is 2.82, and f5 / f is -0.72; 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.

[0144] 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:

[0145] n1 is 1.632, n2 is 1.632, n3 is 1.535, n4 is 1.535, and n5 is 1.632; 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 23.2, the Abbe number of the second lens is 23.2, the Abbe number of the third lens is 55.7, the Abbe number of the fourth lens is 55.7, and the Abbe number of the fifth lens is 23.2.

[0146] In the optical imaging lens group provided by the embodiment three, 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 imaging the scanning curved surface 06 are shown in Table 5:

[0147] Table 5 Structure parameters of the optical imaging lens group in the embodiment three

[0148] Surface Lens Number Surface Form Radius of Curvature Thickness / Spacing Material Material Refractive Index Dispersion Coefficient 0 Imaging Plane Plane Infinity Infinity 1 Stop 05 Infinity 1 2 First Lens 51 Asphere -7.90 0.88 Plastic 1.632 23.2 3 Asphere -4.02 3.91 4 Second Lens 52 Asphere -2.31 0.80 Plastic 1.632 23.2 5 Asphere 2.08 0.10 6 Third Lens 53 Asphere 1.42 1.73 Plastic 1.535 55.7 7 Asphere -0.71 0.30 8 Fourth Lens 54 Asphere -0.70 1.46 Plastic 1.535 55.7 9 Asphere -1.01 0.10 10 Fifth Lens 55 Asphere 1.60 1.09 Plastic 1.632 23.2 11 Asphere 0.51 0.50 12 Scanning Surface 06 Sphere 2

[0149] It should be noted that Table 5 is the detailed structure data of the optical imaging lens group in the embodiment three, wherein the units of the curvature radius, the thickness, and the 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 the curvature radius of “infinity” in the imaging plane means a plane.

[0150] Further, the aspheric conic coefficients of the surfaces corresponding to the first lens 51 to the fifth lens 55 are shown in Table 6 below:

[0151] Table 6: Aspheric conic coefficients of different surfaces in the optical imaging lens group of Example 3

[0152] Surface K A4 A6 A8 2 1.33E+00 3.13E-02 3.79E-03 -1.19E-03 3 5.26E+00 4.75E-02 6.37E-03 1.28E-03 4 -1.52E+01 5.51E-02 -7.43E-02 2.05E-02 5 6.88E-01 -5.06E-02 -1.71E-02 -2.93E-03 6 -5.12E+00 -8.16E-02 6.94E-02 -1.84E-02 7 -2.25E+00 1.01E-02 5.32E-02 -1.49E-02 8 -2.79E+00 2.73E-01 -7.87E-02 7.15E-03 9 -1.72E+00 1.72E-01 -6.70E-02 8.88E-03 10 -2.79E+00 1.41E-01 3.61E-02 -4.66E-02 11 -4.77E-01 -1.15E+00 2.73E+00 -8.96E+00

[0153] Table 6: Aspheric conic coefficients of different surfaces in the optical imaging lens group of 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.

[0154] Further, when the image light corresponding to the scanning surface is projected by the optical imaging lens group, the Modulation Transfer Function (MTF) curve is shown in Figure 12 , the field curvature distortion curve is shown in Figure 13 , and the axial chromatic aberration curve is shown in Figure 14 . The MTF curve 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.

[0155] It can be observed from Figures 12-14 that the optical imaging lens group of Example 3 has good imaging resolution, small optical system distortion, and small chromatic aberration in the full field of view, and thus can clearly image the scanning surface image of the fiber scanner, and has good imaging effect.

[0156] 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.

[0157] Example Four

[0158] Figure 15 A structural diagram of an optical imaging lens group according to an embodiment of the present application is provided. The optical imaging lens group includes a first side (i.e., a side on which the diaphragm 07 in Figure 15 is located) to a second side (i.e., a side on which 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). 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 and 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 lens, but only for naming and distinguishing different elements.

[0159] 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.

[0160] The focal length of the first lens 71 to the sixth lens 76 from the first side to the second side is positive, positive, negative, positive, positive and negative in turn.

[0161] The first side surface of the first lens 71 is concave at the near optical axis, and the second side surface is convex.

[0162] The first side surface of the second lens 72 is concave at the near optical axis, and the second side surface is convex.

[0163] The first side surface and the second side surface of the third lens 73 are both concave.

[0164] The first side surface and the second side surface of the fourth lens 74 are both convex.

[0165] The first side surface of the fifth lens 75 is concave at the near optical axis, and the second side surface is convex at the near optical axis.

[0166] The first side surface of the sixth lens 76 is convex, and the second side surface is concave at the near optical axis.

[0167] In the embodiment, the focal length of the first lens 71 to the sixth lens 76 in the optical imaging lens satisfies the following relationship:

[0168] f1 / f is 17.80, f2 / f is 3.83, f3 / f is -0.90, f4 / f is 0.73, f5 / f is 1.93, and f6 / f is -0.87; 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.

[0169] The refractive indices and dispersion coefficients of the first lens 71 to the sixth lens 76 in the optical imaging lens set satisfy the following conditions respectively:

[0170] n1 is 1.49, n2 is 1.62, n3 is 1.69, n4 is 1.49, n5 is 1.49, and n6 is 1.69. 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 70.4, the Abbe number of the second lens is 60.3, the Abbe number of the third lens is 30.8, the Abbe number of the fourth lens is 70.4, the Abbe number of the fifth lens is 70.4, and the Abbe number of the sixth lens is 49.4.

[0171] In the optical imaging lens set provided by the fourth embodiment of the present application, the equivalent focal length of the optical imaging lens set 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:

[0172] Table 7 Structure parameters of the optical imaging lens set in the fourth embodiment

[0173]

[0174]

[0175] It should be noted that Table 7 is the detailed structure data of the optical imaging lens set 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] Surface K A4 A6 A8 4 1.46E+01 3.22E-02 5.09E-03 -3.13E-03 5 4.65E+00 5.04E-02 1.24E-02 -2.28E-03 6 -3.27E+01 8.63E-02 -4.00E-02 5.47E-03 7 1.85E+00 4.99E-03 -1.22E-02 -7.93E-03 8 -1.43E+00 -4.42E-02 4.98E-02 -1.42E-02 9 -3.74E+00 1.28E-02 4.98E-02 -1.68E-02 10 -1.79E+00 2.80E-01 -8.90E-02 4.86E-03 11 -2.96E+00 1.62E-01 -7.78E-02 1.37E-02 12 -2.95E+00 2.24E-01 -8.67E-02 -2.74E-02 13 -2.30E+00 2.17E-01 2.20E-01 -5.71E+00

[0179] 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.

[0180] Further, when the image light corresponding to the projection scanning surface is projected by using the above optical imaging lens set, 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) curve 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 curve of the vertical axis chromatic aberration represents the chromatic aberration size in the direction perpendicular to the axial direction.

[0181] The optical imaging lens group provided by the embodiment has good imaging resolution in the full field of view, small optical system distortion and chromatic aberration, and can clearly image the curved surface image scanned by the fiber scanner, so that the optical imaging lens group has good imaging effect. Figures 16-18 As can be seen, the optical imaging lens group of the fourth embodiment has good imaging resolution in the full field of view, small optical system distortion and chromatic aberration, and can clearly image the curved surface image scanned by the fiber scanner, so that the optical imaging lens group has good imaging effect.

[0182] 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, 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.

[0183] Embodiment five

[0184] Figure 19 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 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 a stop 09 in the optical imaging lens group is located) to a second side (i.e., a side on which a curved surface 10 in the optical imaging lens group is located). Figure 19 Figure 19 The first lens 91, the second lens 92, the third lens 93, the fourth lens 94 and the fifth lens 95 are arranged in sequence on the same optical axis from the first side to the second side.

[0185] In this 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 have 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.

[0186] The focal lengths of the first lens 91 to the fifth lens 95 from the first side to the second side are positive, negative, positive, positive and negative in sequence.

[0187] The first side surface of the first lens 91 is a concave surface, and the second side surface is a convex surface.

[0188] The first side surface of the second lens 92 is a concave surface, and the second side surface is a concave surface.

[0189] The first side surface of the third lens 93 is a convex surface, and the second side surface is a convex surface near the optical axis.

[0190] The first side surface of the fourth lens 94 is a concave surface near the optical axis, and the second side surface is a convex surface.​

[0191] The first side surface of the fifth lens 95 is convex, and the second side surface is concave at the vicinity of the optical axis.

[0192] In the embodiment, the focal lengths of the first lens 91 to the fifth lens 95 in the optical imaging lens satisfy the following relationship:

[0193] f1 / f is 7.01, f2 / f is -0.98, f3 / f is 0.49, f4 / f is 4.17, and f5 / f is -0.52; 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.

[0194] The refractive indices and the dispersion coefficients of the first lens 91 to the fifth lens 95 in the optical imaging lens satisfy the following conditions respectively:

[0195] n1 is 1.632, n2 is 1.632, n3 is 1.535, n4 is 1.535, and n5 is 1.632; 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 23.2, the Abbe number of the second lens is 23.2, the Abbe number of the third lens is 55.7, the Abbe number of the fourth lens is 55.7, and the Abbe number of the fifth lens is 23.2.

[0196] In the optical imaging lens provided by the embodiment, 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, the thickness parameter, the refractive index, and the dispersion coefficient of each lens in imaging the scanning curved surface 10 are shown in Table 9:

[0197] Table 9 Structure parameters of the optical imaging lens in the embodiment five

[0198] Surface Lens Number Surface Form Radius of Curvature Thickness / Spacing Material Material Refractive Index Dispersion Coefficient 0 Imaging Plane Plane Infinity Infinity 1 Stop 09 Infinity 1 2 First Lens 51 Asphere -6.75 0.83 Plastic 1.632 23.2 3 Asphere -4.55 5.13 4 Second Lens 52 Asphere -4.70 0.80 Plastic 1.632 23.2 5 Asphere 2.85 0.10 6 Third Lens 53 Asphere 2.01 1.79 Plastic 1.535 55.7 7 Asphere -0.69 0.26 8 Fourth Lens 54 Asphere -0.76 1.04 Plastic 1.535 55.7 9 Asphere -0.98 0.10 10 Fifth Lens 55 Asphere 2.09 0.99 Plastic 1.632 23.2 11 Asphere 0.51 0.50 12 Scanning Surface 10 Sphere 2

[0199] It should be noted that Table 9 is the detailed structure data of the optical imaging lens in the embodiment five, wherein the units of the curvature radius, the thickness, and the 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 the curvature radius of “infinity” in the imaging plane means a plane.

[0200] Further, the aspheric conic coefficients of the surfaces corresponding to the first lens 91 to the fifth lens 95 are shown in Table 10:

[0201] Table 10 Aspheric conic coefficient data of different lens surfaces in the embodiment five

[0202] Surface K A4 A6 A8 2 -1.40E+01 3.58E-02 5.78E-03 -2.12E-03 3 6.39E+00 5.19E-02 9.40E-03 5.62E-04 4 -3.40E+00 7.70E-02 -4.26E-02 5.39E-03 5 2.23E+00 1.28E-03 -1.44E-02 -8.01E-03 6 -2.95E+00 -5.02E-02 5.24E-02 -1.50E-02 7 -2.33E+00 1.28E-02 5.29E-02 -1.43E-02 8 -2.35E+00 2.92E-01 -8.14E-02 5.50E-03 9 -2.14E+00 1.83E-01 -7.86E-02 1.09E-02 10 1.25E-01 2.54E-01 -1.78E-01 3.05E-02 11 -6.65E-01 -1.60E-01 -1.88E+00 -2.08E-01

[0203] Table 10 shows the aspheric coefficient data in Example 5, where k is the conical coefficient in the aspheric curve equation, and A4 to A8 represent the 4th to 8th order aspheric coefficients of each surface.

[0204] 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 20 As shown, the field distortion curve is as follows: Figure 21 As shown, the vertical axis color difference curve is as follows: Figure 22 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.

[0205] Depend on Figures 20-22 Observations show that the optical imaging lens group in Example 5 has good imaging resolution and 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.

[0206] 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.

[0207] Scanning display device

[0208] The aforementioned optical imaging lens assembly can be used in conjunction with a fiber optic scanner (or a corresponding fiber optic scanning module) to constitute the scanning display device in the embodiments of this application (e.g., Figure 1a , 1b As shown, the optical imaging lens group is positioned on the output optical path of the fiber optic scanner. The first side of the optical imaging lens group faces the scanning output direction of the fiber optic scanner. Preferably, the optical imaging lens group is coaxial with the central optical axis of the fiber optic scanner. Of course, the structure and general principle of the fiber optic scanner can be found in the aforementioned... Figure 1a , 1b The corresponding content will not be elaborated on here.

[0209] Near-eye display device

[0210] 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.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] The above descriptions are merely preferred embodiments 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 experiments based on the concept of this application should be within the scope of this application.

[0215] 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.

[0216] 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 system, characterized in that, The optical imaging lens group at least comprises 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, the corresponding focal lengths of the first lens to the fifth lens are positive, negative, positive, positive and negative respectively; each of the lenses satisfies the following relationship: 3≤f1 / f≤7, 0.3≤|f2 / f|≤1, 0.48≤f3 / f≤0.53 and 2.82≤f4 / f≤32.84, 0.52≤|f5 / f|≤1.7; 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 1.5-6.0mm.

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: 1.432<n1<1.832, 1.432<n2<1.832, 1.335<n3<1.735, 1.335<n4<1.735, 1.432<n5<1.832; 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.

4. The optical imaging lens according to claim 3, wherein, The n1 is 1.632, the n2 is 1.632, the n3 is 1.535, the n4 is 1.535, and the n5 is 1.

632. The dispersion coefficients of each of the lenses satisfy: the Abbe number of the first lens is 23.2, the Abbe number of the second lens is 23.2, the Abbe number of the third lens is 55.7, the Abbe number of the fourth lens is 55.7, and the Abbe number of the fifth lens is 23.

2.

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 at the near optical axis, 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 first lens is concave or convex, and the second side surface of the first lens is convex.

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

8. A scanning display device, characterized by The optical imaging lens group comprises an optical fiber scanner for scanning and emitting light of an image to be displayed, and the optical imaging lens group is used for magnifying and imaging and projecting a scanning surface corresponding to the light emitted by the optical fiber scanner. The optical fiber scanner comprises an actuator and an optical fiber fixed on the actuator, and the part of the optical fiber 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, comprising: The near-eye display device is used as a head-mounted augmented reality device, and at least comprises 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 at least comprises a near-eye display module and the scanning display device according to claim 8, which is arranged in the near-eye display module.

Images