CN216561179U

CN216561179U - Optical imaging lens group, scanning display device and near-to-eye display equipment

Info

Publication number: CN216561179U
Application number: CN202122538169.0U
Authority: CN
Inventors: 不公告发明人
Original assignee: Chengdu Idealsee Technology Co Ltd
Current assignee: Chengdu Idealsee Technology Co Ltd
Priority date: 2021-10-21
Filing date: 2021-10-21
Publication date: 2022-05-17
Anticipated expiration: 2031-10-21

Abstract

The embodiment of the utility model discloses an optical imaging lens group, a scanning display device and near-to-eye display equipment, and relates to the technical field of scanning display. The optical imaging lens group reasonably optimizes the focal lengths of five lenses with the same optical axis, can reasonably disperse the focal power of a system, slows down the aberration generated by the lenses, and achieves the aim of correcting various aberrations, thereby realizing clear imaging of an image side curved surface on the basis of improving the field angle; the refractive index, the dispersion coefficient and the surface type structure of the five lenses with the same optical axis are limited and optimized, so that the field angle and the imaging quality are further improved; through limiting and optimizing five lenses with the same optical axis to be designed into an aspheric surface-shaped structure, the imaging quality is further improved, the overall structural configuration of the optical imaging lens group can be more compact, and the production requirement of miniaturization of lens products is met.

Description

Optical imaging lens group, scanning display device and near-to-eye display equipment

Technical Field

The utility model relates to the technical field of scanning display, in particular to an optical imaging lens group, a scanning display device and near-to-eye display equipment.

Background

Scanning display imaging is a new display technology, and can be used for various application scenes such as projection display, near-eye display and the like.

However, the existing scanning display imaging system has the disadvantages of high processing difficulty, high volume production cost, poor imaging quality, small viewing angle, and being incapable of miniaturization, so that the scanning display imaging technology is limited in the market popularization and application process, and especially when the scanning display imaging is applied to a near-eye display scene, the scanning display imaging technology is limited by the influence of the imaging effect and the viewing angle, so that the scanning display imaging technology cannot meet the performance requirement of high resolution in near-eye display at all times, and the development of the near-eye display to the consumer-grade market is hindered.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an optical imaging lens group, a scanning display device and a near-eye display device, which are used for meeting the requirements of large field angle, high imaging quality and miniaturization in a near-eye display scene.

The embodiment of the present invention provides an optical imaging lens group, which sequentially includes, from a first side to a second side along an optical axis: the lens comprises a first lens with a positive focal length, a second lens with a positive focal length, a third lens with a negative focal length, a fourth lens with a negative focal length and a fifth lens with a positive focal length, wherein the optical centers of the lenses are positioned on the same straight line.

Optionally, focal lengths of the first to fifth lenses satisfy the following relation: f1/f is more than or equal to 1.09 and less than or equal to 1.29, f2/f is more than or equal to 1.04 and less than or equal to 1.27, f3/f is more than or equal to 0.46 and less than or equal to-0.3, f4/f is more than or equal to 3.85 and less than or equal to-1.18, and f5/f is more than or equal to 0.44 and less than or equal to 0.51; wherein f1 is a focal length of the first lens element, f2 is a focal length of the second lens element, f3 is a focal length of the third lens element, f4 is a focal length of the fourth lens element, f5 is a focal length of the fifth lens element, and f is a focal length of the optical imaging lens assembly.

Optionally, the refractive indices of the first to fifth lenses satisfy the following relations: n1 is more than or equal to 1.56 and less than or equal to 1.57, n2 is more than or equal to 1.49 and less than or equal to 1.53, n3 is more than or equal to 1.75 and less than or equal to 1.76, n4 is more than or equal to 1.73 and less than or equal to 1.74, and n5 is more than or equal to 1.56 and less than or equal to 1.62; wherein n1 is a refractive index of the first lens, n2 is a refractive index of the second lens, n3 is a refractive index of the third lens, n4 is a refractive index of the fourth lens, and n5 is a refractive index of the fifth lens.

Optionally, the refractive indices of the first to fifth lenses satisfy the following condition: the n1 is 1.56 or 1.57, the n2 is 1.49 or 1.53, the n3 is 1.75 or 1.76, the n4 is 1.73 or 1.74, and the n5 is 1.56 or 1.62.

Optionally, the abbe numbers of the first lens to the fifth lens satisfy the following relations: v1 is more than or equal to 43.5 and less than or equal to 46.8, v2 is more than or equal to 65.9 and less than or equal to 70, v3 is more than or equal to 27.5 and less than or equal to 27.6, v4 is more than or equal to 34.5 and less than or equal to 44.9, and v5 is more than or equal to 60.3 and less than or equal to 63.9; 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.

Optionally, the abbe numbers of the first lens to the fifth lens satisfy the following condition: the abbe number of the first lens is 43.5 or 46.8, the abbe number of the second lens is 65.9 or 70, the abbe number of the third lens is 27.5 or 27.6, the abbe number of the fourth lens is 34.5 or 44.9, and the abbe number of the fifth lens is 60.3 or 63.9.

Optionally, the first side surface of the first lens is a concave surface or a convex surface, and 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 convex surfaces; a first side surface of the third lens is concave, a second side surface of the third lens is concave at a paraxial region; the first side surface of the fourth lens is a concave surface, and the second side surface of the fourth lens is a concave surface or a convex surface; the first side surface of the fifth lens element is convex and the second side surface of the fifth lens element is concave at a paraxial region.

Optionally, the first side surface and the second side surface of each of the first lens to the fifth lens are aspheric surface-shaped 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.

The embodiment of the utility model also provides a scanning display device, which comprises an optical fiber scanner and the optical imaging lens group, wherein the optical fiber scanner is used for scanning and emitting light of an image to be displayed, and the optical imaging lens group is used for amplifying, 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, wherein a part of the optical fiber, which exceeds the actuator, forms an optical fiber cantilever, and the optical fiber cantilever is driven by the actuator to perform two-dimensional scanning.

The embodiment of the utility model also provides near-eye display equipment, which is used as head-mounted augmented reality equipment or head-mounted virtual reality equipment and at least comprises a near-eye display module and the scanning display device, wherein the scanning display device is arranged in the near-eye display module.

By adopting the technical scheme in the embodiment of the utility model, the following technical effects can be realized:

in the embodiment of the utility model, the focal lengths of five lenses with the same optical axis of the optical imaging lens group are reasonably and optimally set, so that the focal power of the system can be reasonably dispersed, the aberration generated by the lenses is reduced, and the aim of correcting various aberrations is fulfilled, thereby realizing clear imaging of an image space curved surface on the basis of improving the field angle; meanwhile, the optical imaging lens group is more compact in overall structure through the combination and configuration of a reasonable number of lenses, and the production requirement for miniaturization of lens products is met.

Furthermore, the refractive index, the dispersion coefficient and the surface type structure of the five coaxial lenses are limited and optimized, so that the field angle and the imaging quality are further improved.

Additional features and advantages of the utility model will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model. The objectives and other advantages of the utility model may be realized and attained by the structure and/or process particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

Other features, objects and advantages of the utility model will become more apparent upon reading of the detailed description of non-limiting embodiments made with reference to the following drawings:

fig. 1a and 1b are schematic structural diagrams of a scanning display system according to an embodiment of the present invention;

FIG. 2a is a schematic diagram of the scan output of a fiber scanner provided by an embodiment of the present invention;

fig. 2b is a schematic diagram of a positional relationship between the optical imaging lens group provided by the embodiment of the present invention and the entrance pupil position, the exit pupil position and the corresponding exit pupil distance;

FIG. 3 is a schematic structural diagram of an optical imaging lens assembly according to an embodiment of the present invention;

FIG. 4 is a MTF graph of an optical imaging lens assembly according to an embodiment of the present invention;

FIG. 5 is a graph of field curvature distortion of an optical imaging lens assembly according to an embodiment of the present invention;

FIG. 6 is a vertical axis chromatism chart of an optical imaging lens assembly according to an embodiment of the present invention.

FIG. 7 is a schematic structural diagram of an optical imaging lens assembly according to a second embodiment of the present invention;

FIG. 8 is a MTF graph of the optical imaging lens assembly according to the second embodiment of the present invention;

FIG. 9 is a graph of field curvature distortion of the optical imaging lens assembly of the second embodiment of the present invention;

FIG. 10 is a vertical axis chromatism chart of the optical imaging lens assembly according to the second embodiment of the present invention;

fig. 11 is a schematic structural diagram of an optical imaging lens assembly according to a third embodiment of the present invention;

FIG. 12 is a MTF graph of an optical imaging lens assembly according to a third embodiment of the present invention;

FIG. 13 is a graph of curvature of field distortion of an optical imaging lens assembly according to a third embodiment of the present invention;

FIG. 14 is a vertical axis chromatism chart of the optical imaging lens assembly according to the third embodiment of the present invention;

FIG. 15 is a schematic structural diagram of an optical imaging lens assembly according to a fourth embodiment of the present invention;

FIG. 16 is a MTF graph of an optical imaging lens assembly according to a fourth embodiment of the present invention;

FIG. 17 is a graph of field curvature distortion of an optical imaging lens assembly in a fourth embodiment of the present invention;

FIG. 18 is a vertical axis chromatism chart of the optical imaging lens assembly according to the fourth embodiment of the present invention.

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

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the utility model. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.

Scanning display system

For current Scanning Display imaging, it can be realized by Digital Micromirror Device (DMD) or Fiber Scanning Display (FSD) Device. The FSD scheme is used as a novel scanning display imaging mode, and the scanning output of images is realized through an optical fiber scanner. In order to make the solution of the present invention clearly understandable to those skilled in the art, the following provides a brief description of the principles of fiber scanning imaging and a corresponding system.

As shown in fig. 1a, a scanning display system provided in an embodiment of the present invention mainly includes:

the optical fiber scanning device comprises a processor 100, a laser group 110, a fiber scanning module 120, a transmission fiber 130, a light source modulation circuit 140, a scanning driving circuit 150 and a beam combining unit 160. Wherein the content of the first and second substances,

the processor 100 may be a Graphics Processing Unit (GPU), a Central Processing Unit (CPU), or other chips or circuits having a control function and an image Processing function, and is not limited in particular.

When the system works, the processor 100 may control the light source modulation circuit 140 to modulate the laser group 110 according to image data to be displayed, where the laser group 110 includes a plurality of monochromatic lasers, and the lasers emit light beams of different colors respectively. As shown in fig. 1a, three-color lasers of Red (R), Green (G) and Blue (B) can be specifically used in the laser group. The light beams emitted by the lasers in the laser group 110 are combined into a laser beam by the beam combining unit 160 and coupled into the transmission fiber 130.

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

The light beam scanned and output by the optical fiber scanner acts on a certain pixel point position on the surface of the medium, and forms a light spot on the pixel point position, so that the pixel point position is scanned. Under the driving of the optical fiber scanner, the output end of the transmission optical fiber 130 sweeps according to a certain scanning track, so that the light beam moves to the corresponding pixel point position. During actual scanning, the light beam output by the transmission fiber 130 will form a light spot with corresponding image information (e.g., color, gray scale or brightness) at each pixel location. In a frame time, the light beam traverses each pixel position at a high enough speed to complete the scanning of a frame of image, and because the human eye observes the object and has the characteristic of 'visual residual', the human eye cannot perceive the movement of the light beam at each pixel position but sees a frame of complete image.

With continued reference to fig. 1b, a specific structure of the fiber scanning module 120 is shown, which includes: scanning actuator 121, fiber suspension 122, mirror group 123, scanner package 124 and fixing member 125. The scanning actuator 121 is fixed in the scanner packaging case 124 through a fixing member 125, and the transmission fiber 130 extends at the front end of the scanning actuator 121 to form a fiber suspension 122 (also called a scanning fiber), so that, in operation, the scanning actuator 121 is driven by a scanning driving signal, the slow axis 121a (also called as the first actuating portion) vibrates along the vertical direction (the vertical direction is parallel to the Y axis in the reference coordinate system in fig. 1a and 1b, in the present invention, the vertical direction may also be called as the first direction), the fast axis 121b (also called as the second actuating portion) vibrates along the horizontal direction (the horizontal direction is parallel to the X axis in the reference coordinate system in fig. 1a and 1b, in the present invention, the horizontal direction may also be called as the second direction), the front end of the fiber cantilever 122 is driven by the scanning actuator 121 to perform two-dimensional scanning according to a predetermined track and emit a light beam, and the emitted light beam can pass through the mirror assembly 123 to realize scanning and imaging. In general, the structure formed by the scan actuator 121 and the fiber suspension 122 can be referred to as: an optical fiber scanner.

As shown in fig. 2a, in the embodiment of the present invention, the movement locus of the light exit end of the optical fiber forms a scanning curved surface 230 through the movement of the fast and slow axes, and is converted into an imaging plane 240 after passing through the corresponding mirror group 123. When applied in a near-eye display device such as an Augmented Reality (AR) device, the imaging plane 240 couples the entrance pupil as a waveguide into the waveguide for imaging for viewing by the human eye.

For convenience of description and to make those skilled in the art easily understand the solution of the present invention, it should be noted that the optical imaging lens assembly (such as the lens assembly 123 shown in fig. 2 a) in the present invention is used as an eyepiece, and under the action of the optical imaging lens assembly, the scanning curved surface 230 can be converted into an imaging plane 240 (in practical application, the transmission direction of light is from the scanning curved surface 230 to the imaging plane 240), so that one side of the optical imaging lens assembly corresponding to the imaging plane 240 is referred to as a first side, and one side of the optical imaging lens assembly corresponding to the scanning curved surface 230 is referred to as a second side. In the following, embodiments of the optical imaging lens group will be described with reference to "the first side" and "the second side". Also, 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 X-th lens" refers to a surface of the X-th lens facing the first side.

It should be further noted that, in the field of projection, the image corresponding to the first side is a planar image, the corresponding planar image carrier may be a projection screen, a curtain, or a wall surface, etc., and the image corresponding to the second side is a curved image, i.e., an arc-shaped scanning surface scanned by the optical fiber scanner or emitted by another image source; in a use scene of the camera shooting field, the light path is opposite to that in the projection field, 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 imaging.

Optical imaging lens group

The optical imaging lens group in the embodiment of the utility model at least comprises: along optical axis from first side to second side, optical imaging mirror group sets up in proper order at least: the lens comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens, and the optical centers of the lenses are located on the same straight line, namely the optical centers of the five lenses are located on the same main optical axis.

In the embodiment of the present invention, the first lens has a positive focal length, the second lens has a positive focal length, the third lens has a negative focal length, the fourth lens has a negative focal length, and the fifth lens has a positive focal length. It should be noted that, by simultaneously carrying out positive and negative reasonable optimization setting on the focal lengths of the five lenses with the same optical axis, the focal power of the system can be reasonably dispersed, the aberration generated by the lenses can be reduced, and the purpose of correcting various aberrations can be achieved, so that clear imaging of an image square curved surface can be realized on the basis of improving the angle of view.

In addition, it is emphasized that by setting the focal length of the fifth lens to a positive focal length, the converging ability of the curved image can be further enhanced to balance the aberration.

Further, in one possible embodiment, the focal lengths of the various lenses may satisfy the following relationships: f1/f is more than or equal to 1.09 and less than or equal to 1.29, f2/f is more than or equal to 1.04 and less than or equal to 1.27, f3/f is more than or equal to 0.46 and less than or equal to-0.3, f4/f is more than or equal to 3.85 and less than or equal to-1.18, and f5/f is more than or equal to 0.44 and less than or equal to 0.51; wherein f is₁Is the focal length of the first lens, f₂Is the focal length of the second lens, f₃Is the focal length of the third lens, f₄Is the focal length of the fourth lens, f₅F is the focal length of the fifth lens element, and f is the focal length of the optical imaging lens assembly (which can also be understood as the equivalent focal length of the optical imaging lens assembly).

It should be noted that, in the optical imaging lens assembly provided in the embodiment of the present invention, the focal length of each lens is more specifically defined, so that the focal powers of the system are more reasonably dispersed and configured, further the correction of various aberrations is further enhanced, and the field angle and the imaging quality are improved. In addition, if the position of the area where the focal length of the lens 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 paraxial region. Before the utility model is created, the existing optical imaging lens group for projection display cannot achieve the balance between the imaging quality and the large field angle, that is, the imaging quality is generally reduced when the field angle is increased, and a larger field angle cannot be achieved when the imaging quality is ensured. The utility model of the present invention realizes the high quality output of the imaging while increasing the angle of view and achieving miniaturization by the combined control of the focal length and the surface type structure of the five lenses, and in addition, any one or more or all of the lenses may satisfy the above conditions, and it is not limited that each lens satisfies the above relationship at the same time, and it is specifically determined according to the needs of the practical application, and it is not limited herein.

Preferably, the connection mode between the five lenses can be interval connection, and can also be adhesive bonding, which will be determined according to the needs of the practical application, and is not limited here.

Further, in a possible embodiment, the refractive indexes of the various lenses also satisfy the following relation: n1 is more than or equal to 1.56 and less than or equal to 1.57, n2 is more than or equal to 1.49 and less than or equal to 1.53, n3 is more than or equal to 1.75 and less than or equal to 1.76, n4 is more than or equal to 1.73 and less than or equal to 1.74, and n5 is more than or equal to 1.56 and less than or equal to 1.62; where n1 is a refractive index of the first lens, n2 is a refractive index of the second lens, n3 is a refractive index of the third lens, n4 is a refractive index of the fourth lens, and n5 is a refractive index of the fifth lens. Preferably, the refractive index n1 of the first lens is 1.56 or 1.57, the refractive index n2 of the second lens is 1.49 or 1.53, the refractive index n 31.75 or 1.76 of the third lens, the refractive index n4 of the fourth lens is 1.73 or 1.74, and the refractive index n5 of the fifth lens is 1.56 or 1.62.

It should be noted that, by limiting the refractive index of the five lenses through an optimized design, the dispersion coefficient of the corresponding lens can be reasonably controlled to ensure the imaging quality and the large field angle.

Further, in a possible implementation manner, in order to better ensure the imaging quality, the embodiments of the present invention also specifically and preferably limit the abbe numbers of the five lenses, and the abbe numbers of the various lenses satisfy the following relations: v1 is more than or equal to 43.5 and less than or equal to 46.8, v2 is more than or equal to 65.9 and less than or equal to 70, v3 is more than or equal to 27.5 and less than or equal to 27.6, v4 is more than or equal to 34.5 and less than or equal to 44.9, and v5 is more than or equal to 60.3 and less than or equal to 63.9; 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. Preferably, the abbe number of the first lens is 43.5 or 46.8, the abbe number of the second lens is 65.9 or 70, the abbe number of the third lens is 27.5 or 27.6, the abbe number of the fourth lens is 34.5 or 44.9, and the abbe number of the fifth lens is 60.3 or 63.9.

It should be noted that, in other embodiments of the present invention, the abbe numbers of the five lenses defined in the embodiments of the present invention are not limited, and other abbe numbers capable of ensuring that the five lenses have good matching relationship may also be used, so as to ensure the final imaging quality.

Further, in a possible embodiment, the first side surface of the first lens is concave or convex, and the second side surface of the first lens is convex; the first side surface and the second side surface of the second lens are convex surfaces; a first side surface of the third lens is concave, a second side surface of the third lens is concave at a paraxial region; the first side surface of the fourth lens is a concave surface, and the second side surface of the fourth lens is a concave surface or a convex surface; the first side surface of the fifth lens element is convex and the second side surface of the fifth lens element is concave at a paraxial region. By limiting the surface type structure of the corresponding side surface of the lens, the aberration generated between the lenses can be further effectively corrected, the optical sensitivity is reduced, and the final imaging quality and the field angle are improved. In addition, the first side surface is a convex surface, which means that the first side surface is convex toward the first side direction of the optical imaging lens group; the first side surface is a concave surface, which means that the first side surface forms a concave shape towards the first side direction of the optical imaging lens group; the second side surface is a convex surface, which means that the second side surface forms a convex shape towards the second side direction of the optical imaging lens group; the second side surface is a concave surface, which means that the second side surface forms a concave shape towards the second side direction of the optical imaging lens group.

It should be emphasized that, in other embodiments of the present invention, the surface structure of all lenses is not limited to be defined simultaneously as in this embodiment, and the surface structure of at least one lens may also be defined only as the surface structure of the first side surface and the second side surface of the fifth lens, and the surface structure of the other lenses is not limited.

In addition, in some embodiments, the lens surface shape is not concave or convex over the entire side surface, and may be a compound curve, or a curve near the optical axis portion and a non-curve at the edge portion; when the lens surface is convex and the position of the convex surface is not defined, the convex surface can be positioned at the position of the lens surface near the optical axis; similarly, when the lens surface is concave and the position of the concave is not defined, it means that the concave can be located at the position of the lens surface near the optical axis.

Further, in a possible embodiment, the first side surface and the second side surface of the first lens to the fifth lens are both aspheric surface shaped structures. It should be noted that the aspheric lens has the following characteristics: the curvature of the lens from the center to the periphery is continuously changed, and the aspheric lens has better curvature radius characteristics and has the advantages of improving curvature aberration and improving astigmatic difference, and the mirror surface structures of the first lens to the fifth lens are limited and designed into aspheric surface-shaped structures, so that more control variables can be obtained for reducing aberration and reasonably reducing the number of the lenses, and the miniaturization of the optical imaging lens group is facilitated on the basis of improving the image display quality. In addition, the first side surface and the second side surface of the lens are both aspheric surface structures, and it can be understood that the whole or a part of the optical effective area of the lens surface is aspheric.

Further, in one possible embodiment, the first to fifth lenses are each 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 lens is one twentieth to one tenth of the cost of the glass material, so that the low-cost mass production is very facilitated. In addition, the plastic lens can be generally formed by injection molding, has low processing difficulty and can be easily processed into various profile structures meeting the aspheric surface, and meanwhile, the plastic lens can also integrally reduce the weight of the lens, thereby being beneficial to the light product design. When the glass material is used, the refractive index of the glass material is higher and wider, and the glass material has advantages in the aspect of correcting lens aberration; the glass material has a small expansion coefficient, which is beneficial to precision assembly, and in addition, the glass has the characteristics of high temperature resistance, ultraviolet resistance, acid and alkali resistance and the like, so that the service life and the performance stability of the lens group have strong advantages, and the influence of temperature on the optical back focus of the lens can be reduced. It should be emphasized that, of course, in other embodiments of the present invention, the material is not limited to the plastic and the glass provided in the embodiments of the present invention, and may be other materials capable of forming a lens.

In addition, it should be further noted that, optionally, at least one stop may be disposed before the first lens element (on the first side), between the lens elements, or after the last fifth lens element (on the second side), and the type of the stop may be, for example, an aperture stop or a field stop, which may be used to reduce stray light and help to improve image display quality.

Further, in some embodiments, the optical imaging lens group in the present embodiments further satisfies the following optical characteristics:

a plurality of lenses in the optical imaging lens group are sequentially arranged in a coaxial manner from an entrance pupil position to an exit pupil position, and the exit pupil position of the optical imaging lens group corresponds to a curved image, namely corresponds to the second side of the optical imaging lens group; the entrance pupil position of the optical imaging lens group corresponds to the planar image, i.e. corresponds to the first side of the optical imaging lens group. It should be noted that, referring to fig. 1a to fig. 2b (fig. 2b illustrates an example of an optical imaging lens assembly including 6 lenses), a lens surface (i.e., a lens surface closest to the curved image) of the plurality of lenses close to and opposite to the exit pupil position is a concave surface, an intersection point is formed by crossing the optical axis and the concave surface, a distance between the intersection point and the exit pupil position is an exit pupil distance, the exit pupil distance is 1.5-6.0mm, and preferably, the exit pupil distance is 2-3.5 mm. It should be noted that, by limiting the lens surface shape structure and the corresponding exit pupil distance of the lens close to the curved surface image in the multiple coaxial lenses of the optical imaging lens group, the lens surface shape structure can be matched with the corresponding curved surface scanning image, thereby realizing clear imaging from the curved surface image to the plane image.

In addition, it should be further explained that please continue to refer to fig. 2 b:

entrance pupil: the entrance pupil is an effective aperture for limiting an incident beam, is an image formed by the aperture diaphragm on a front optical system, is a conjugate phase of the aperture diaphragm in an object space, and corresponds to the exit pupil;

entrance pupil position: the entrance pupil position is a position point where the aperture stop forms an image on the front optical system, and is calculated by taking the center of the aperture stop as an object point, tracing the light beam to the front optical system, obtaining coordinates of an intersection point with a point on the optical axis, and usually setting the distance from the surface of the first lens as the entrance pupil distance.

Exit pupil: the aperture diaphragm of the optical system forms an image in the image space of the optical system as the exit pupil of the lens;

exit pupil position: the exit pupil position is a position point where the aperture stop images the rear optical system, and is calculated by regarding the center of the aperture stop as an object point, tracing the light rays to the rear optical system to obtain the coordinates of the intersection point with the point on the optical axis, and usually taking the distance from the last lens surface as the exit pupil distance.

Measurement of exit pupil position: a1 point light source is arranged at the center of an entrance pupil position, imaging is carried out through a designed lens, and the optimal imaging position of the point light source is the exit pupil position.

More specifically, as shown in fig. 2b, there are an entrance pupil (entrance pupil position), an optical imaging lens group, and an exit pupil (exit pupil position) in sequence from left to right, i.e. from the first side to the second side.

Example one

Fig. 3 is a schematic structural diagram of an optical imaging lens assembly according to an embodiment of the present invention. The optical imaging lens group is provided with a first lens 11, a second lens 12, a third lens 13, a fourth lens 14 and a fifth lens 15 in sequence from a first side (i.e. the side where the diaphragm 01 is located in fig. 3) to a second side (i.e. the side where the scanning curved surface 02 is located in fig. 3) along an optical axis.

In this embodiment, each two adjacent lenses of the first lens 11, the second lens 12, the third lens 13, the fourth lens 14, and the fifth lens 15 have a space therebetween, 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-cemented lenses, and the optical centers of the respective lenses are located on the same straight line, that is, the optical centers of the respective lenses are located on the same main optical axis.

Wherein, the focal length of the first lens 11 is positive, and the first side surface of the first lens 11 is a concave surface, and the second side surface is a convex surface; the focal length of the second lens 12 is positive, and the first side surface of the second lens 12 is a convex surface, and the second side surface is also a convex surface; the focal length of the third lens 13 is negative, and the first side surface of the third lens 13 is concave, and the second side surface is concave at the paraxial region; the focal length of the fourth lens 14 is negative, and the first side surface of the fourth lens 14 is a concave surface and the second side surface is a concave surface; the focal length of the fifth lens element 15 is positive, and the first side surface of the fifth lens element 15 is convex and the second side surface is concave at the paraxial region.

Optionally, in this embodiment, the focal lengths of the first lens 11 to the fifth lens 15 may further satisfy the following relations: f. of₁F is 1.09, f₂F is 1.15, f₃F is-0.30, f₄F is-3.85 and f₅The value of/f is 0.44; wherein f is₁Is the focal length of the first lens 11, f₂Is the focal length of the second lens 12, f₃Is the focal length of the third lens 13, f₄Is the focal length of the fourth lens 14, f₅F is the focal length of the fifth lens element 15, and f is the equivalent focal length of the optical imaging lens assembly.

Optionally, in this embodiment, the refractive indexes of the first lens 11 to the fifth lens 15 may also satisfy the following condition: n1 is 1.56, n2 is 1.49, n3 is 1.76, n4 is 1.73, and n5 is 1.62. Where n1 to n5 represent refractive indices of the first lens 11 to the fifth lens 15, respectively.

Optionally, in this embodiment, the abbe numbers of the first lens 11 to the fifth lens 15 may further satisfy the following condition: the abbe number of the first lens is 46.8, the abbe number of the second lens is 70, the abbe number of the third lens is 27.5, the abbe number of the fourth lens is 34.5, and the abbe number of the fifth lens is 60.3.

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

TABLE 1 structural parameters of the optical imaging lens assembly in the first embodiment

Surface of	Lens serial number	Surface shape	Radius of curvature	Thickness/spacing	Refractive index of material	Coefficient of dispersion
							0	Imaging plane	Plane surface	Infinite number of elements	Infinite number of elements
1	Diaphragm 01		Unlimited in size	1
							2	First lens 11	Aspherical surface	-5.83	1.79	1.56	46.8
3		Aspherical surface	-1.40	0.51
							4	Second lens 12	Aspherical surface	13.93	1.03	1.49	70
5		Aspherical surface	-1.62	0.11
							6	Third lens 13	Aspherical surface	-1.45	0.60	1.76	27.5
7		Aspherical surface	1.22	0.25
							8	Fourth lens 14	Aspherical surface	-65.46	0.63	1.73	34.5
9		Aspherical surface	8.32	0.39
							10	Fifth lens 15	Aspherical surface	0.67	1.44	1.62	60.3
11		Aspherical surface	2.45	0.50
							12	Scanning curved surface 02	Spherical surface	2

It should be noted that table 1 is detailed structural data of the optical imaging lens assembly of the first embodiment, wherein the units of the radius of curvature, the thickness (pitch) and the focal length are all millimeters, and surfaces 0-12 sequentially represent the surfaces from the first side to the second side; an optical surface in the imaging plane with a radius of curvature of "infinity" is referred to as a flat surface.

Further, aspherical conic coefficients of the corresponding surfaces of the first lens 11 to the fifth lens 15 are shown in table 2 below:

TABLE 2 aspherical Cone coefficient data for different lens surfaces in example one

Surface of	K	A4	A6	A8
					2	1.24E+01	5.14E-04	5.72E-03	1.29E-03
3	-1.44E+00	4.43E-02	-1.73E-02	4.54E-03
					4	1.40E+02	2.39E-02	-2.21E-02	-5.61E-03
5	-3.45E+01	8.59E-02	-1.47E-01	4.41E-02
					6	-2.50E+01	-1.46E-02	3.24E-02	-2.89E-02
7	-8.39E+00	-1.70E-01	1.37E-01	-7.02E-02
					8	-4.00E+02	-7.28E-02	1.15E-01	-4.81E-02
9	-8.85E+02	-9.92E-02	1.51E-01	-2.19E-02
					10	-2.07E+00	2.09E-01	-7.00E-02	3.72E-02
11	2.78E+00	2.74E-01	-6.70E-01	3.62E-01

Table 2 shows the aspheric coefficient data of the first embodiment, wherein k is the cone coefficient in the aspheric curve equation, and a4 to A8 represent the 4 th to 8 th order aspheric coefficients of each surface.

Further, through tests, when the optical imaging lens group is adopted to project image light corresponding to a scanning surface, an optical transfer function curve graph is shown in fig. 4, a field curvature distortion curve graph is shown in fig. 5, and a vertical axis chromatic aberration curve graph is shown in fig. 6; the Modulation Transfer Function (MTF) is a quantitative description of the resolution of the lens, and represents a comprehensive resolution level of an optical system, specifically a quantitative description of the degree of sharpness (including two factors of resolution and sharpness) of the lens image, the field curvature distortion curve represents the F-tan (theta) distortion value (percentage) under different field angles, and the vertical axis chromatic aberration curve represents the chromatic aberration in the direction perpendicular to the axial direction.

As can be seen from fig. 4-6, the optical imaging lens assembly of the first embodiment has good imaging resolution and small distortion and chromatic aberration of the optical system in the full field of view, so that the optical imaging lens assembly can clearly image the scanning curved image of the optical fiber scanner, and has good imaging effect.

Certainly, in practical applications, the optical imaging lens assembly may further include a display element, a housing, and the like, the display element may be disposed at the second side of the optical imaging lens assembly, and the optical imaging lens assembly may be mounted in the housing, so that a curved image formed by scanning an image source (such as an optical fiber scanner) may be imaged on a plane, thereby realizing clear imaging.

Example two

Fig. 7 is a schematic structural diagram of an optical imaging lens assembly according to an embodiment of the present invention. The optical imaging lens group is provided with a first lens 31, a second lens 32, a third lens 33, a fourth lens 34 and a fifth lens 35 in sequence from a first side (i.e., the side where the diaphragm 03 is located in fig. 7) to a second side (i.e., the side where the scanning curved surface 04 is located in fig. 7) along the optical axis.

In this embodiment, each two adjacent lenses of the first lens 31, the second lens 32, the third lens 33, the fourth lens 34, and the fifth lens 35 have a space therebetween, 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-cemented lenses, and the optical centers of the respective lenses are located on the same straight line, that is, the optical centers of the respective lenses are located on the same main optical axis.

Wherein the focal length of the first lens element 31 is positive, and the first side surface of the first lens element 31 is convex, and the second side surface is convex at the paraxial region; the focal length of the second lens 32 is positive, and the first side surface of the second lens 32 is a convex surface, and the second side surface is also a convex surface; the focal length of the third lens element 33 is negative, and the first side surface of the third lens element 33 is concave and the second side surface is concave at the paraxial region; the focal length of the fourth lens element 34 is negative, and the first side surface of the fourth lens element 34 is concave at the paraxial region and the second side surface is convex at the paraxial region; the focal length of the fifth lens element 35 is positive, and the first side surface of the fifth lens element 35 is convex and the second side surface is concave at the paraxial region.

Optionally, in this embodiment, the focal lengths of the first lens 31 to the fifth lens 35 may satisfy the following relations: f. of₁F is 1.29, f₂F is 1,27, f₃F is-0.38, f₄F is-3.85 and f₅The value of/f is 0.50; wherein f is₁Is the focal length of the first lens 31, f₂Is the focal length of the second lens 32, f₃Is the focal length of the third lens 33, f₄Is the focal length of the fourth lens 34, f₅Is the focal length of the fifth lens element 35, and f is the equivalent focal length of the optical imaging lens assembly.

Optionally, in this embodiment, the refractive indexes of the first lens 31 to the fifth lens 35 may further satisfy the following condition: n1 is 1.57, n2 is 1.53, n3 is 1.76, n4 is 1.74, and n5 is 1.56. Wherein n1 to n5 represent refractive indices of the first lens 31 to the fifth lens 35, respectively.

Optionally, in this embodiment, the abbe numbers of the first lens 31 to the fifth lens 35 may also satisfy the following condition: the abbe number of the first lens is 43.5, the abbe number of the second lens is 65.9, the abbe number of the third lens is 27.6, the abbe number of the fourth lens is 44.9, and the abbe number of the fifth lens is 63.9.

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

TABLE 3 structural parameters of the optical imaging lens assembly in the second embodiment

Surface of	Lens serial number	Surface shape	Radius of curvature	Thickness/spacing	Refractive index of material	Coefficient of dispersion
							0	Imaging plane	Plane surface	Infinite number of elements	Infinite number of elements
1	Diaphragm 03			1
							2	First lens 31	Aspherical surface	14.77	1.83	1.57	43.5
3		Aspherical surface	-2.11	0.31
							4	Second lens 32	Aspherical surface	13.78	0.89	1.53	65.9
5		Aspherical surface	-1.99	0.11
							6	Third lens 33	Aspherical surface	-1.91	0.60	1.76	27.6
7		Aspherical surface	1.45	0.25
							8	Fourth lens 34	Aspherical surface	-3.62	0.74	1.74	44.9
9		Aspherical surface	-7.60	0.48
							10	Fifth lens 35	Aspherical surface	0.67	1.42	1.56	63.9
11		Aspherical surface	1.71	0.50
							12	Scanning curved surface 04	Spherical surface	2

It should be noted that table 3 is detailed structural data of the optical imaging lens assembly of the second embodiment, wherein the units of the radius of curvature, the thickness (pitch), and the focal length are all millimeters, and the surfaces 0-12 sequentially represent the surfaces from the first side to the second side; an optical surface in the imaging plane with a radius of curvature of "infinity" is referred to as a flat surface.

Further, aspherical conic coefficients of the corresponding surfaces of the first lens 31 to the fifth lens 35 are shown in table 4 below:

TABLE 4 aspherical Cone coefficient data for different lens surfaces in example two

Surface of	K	A4	A6	A8
					2	-3.63E+01	1.66E-02	8.73E-03	-1.74E-03
3	-2.91E+00	6.57E-02	-5.16E-03	1.43E-02
					4	1.44E+02	1.29E-02	-2.06E-02	-1.15E-03
5	-2.90E+01	8.82E-02	-1.47E-01	4.07E-02
					6	-2.28E+01	-2.07E-02	2.81E-02	-2.83E-02
7	-1.16E+01	-1.76E-01	1.36E-01	-6.01E-02
					8	-1.43E+02	-5.76E-02	1.24E-01	-5.06E-02
9	-9.42E+01	-1.16E-01	1.44E-01	-2.44E-02
					10	-1.83E+00	1.90E-01	-3.96E-02	2.81E-02
11	3.05E+00	1.45E-01	-6.22E-01	5.45E-02

Table 4 shows aspheric coefficient data of the second embodiment, where k is the cone coefficient in the aspheric curve equation, and a4 to A8 represent the 4 th to 8 th order aspheric coefficients of each surface.

Further, through tests, when the optical imaging lens group is adopted to project image light corresponding to a scanning surface, an optical transfer function curve graph is shown in fig. 8, a field curvature distortion curve graph is shown in fig. 9, and a vertical axis chromatic aberration curve graph is shown in fig. 10; the Modulation Transfer Function (MTF) is a quantitative description of the resolution of the lens, and represents a comprehensive resolution level of an optical system, specifically a quantitative description of the degree of sharpness (including two factors of resolution and sharpness) of the lens image, the field curvature distortion curve represents the F-tan (theta) distortion value (percentage) under different field angles, and the vertical axis chromatic aberration curve represents the chromatic aberration in the direction perpendicular to the axial direction.

As can be seen from fig. 8-10, the optical imaging lens assembly of the second embodiment has good imaging resolution and small distortion and chromatic aberration of the optical system in the full field of view, so that the optical imaging lens assembly can clearly image the scanning curved image of the optical fiber scanner, and has good imaging effect.

EXAMPLE III

Fig. 11 is a schematic structural diagram of an optical imaging lens assembly according to an embodiment of the present invention. The optical imaging lens group is provided with a first lens 51, a second lens 52, a third lens 53, a fourth lens 54 and a fifth lens 55 in sequence from a first side (i.e. the side where the diaphragm 05 is located in fig. 11) to a second side (i.e. the side where the scanning curved surface 06 is located in fig. 11) along the optical axis.

In this embodiment, each two adjacent lenses of the first lens 51, the second lens 52, the third lens 53, the fourth lens 54, and the fifth lens 55 have a space therebetween, 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-cemented lenses, and the optical centers of the respective lenses are located on the same straight line, that is, the optical centers of the respective lenses are located on the same main optical axis.

Wherein the focal length of the first lens element 51 is positive, and the first side surface of the first lens element 51 is convex, and the second side surface is convex at the paraxial region; the focal length of the second lens 52 is positive, and the first side surface of the second lens 52 is convex, and the second side surface is also convex; the focal length of the third lens 53 is negative, and the first side surface of the third lens 53 is concave, and the second side surface is concave at the paraxial region; the focal length of the fourth lens element 54 is negative, and the first side surface of the fourth lens element 54 is concave at paraxial region and the second side surface is convex at paraxial region; the focal length of the fifth lens element 55 is positive, and the first side surface of the fifth lens element 55 is convex and the second side surface is concave at the paraxial region.

Optionally, in this embodiment, the focal lengths of the first lens 51 to the fifth lens 55 may further satisfy the following relations: f. of₁F is 1.23, f₂F is 1.04, f₃F is-0.46, f₄F is-1.18 and f₅The value of/f is 0.51; wherein f is₁Is the focal length of the first lens 51, f₂Is the focal length of the second lens 52, f₃Is the focal length of the third lens 53, f₄Is the focal length of the fourth lens 54, f₅Is the focal length of the fifth lens element 55, and f is the equivalent focal length of the optical imaging lens assembly.

Optionally, in this embodiment, the refractive indexes of the first lens 51 to the fifth lens 55 may also satisfy the following conditions: n1 is 1.56, n2 is 1.49, n3 is 1.75, n4 is 1.73, and n5 is 1.62. Where n1 to n5 represent refractive indices of the first lens 51 to the fifth lens 55, respectively.

Optionally, in this embodiment, the abbe numbers of the first lens 51 to the fifth lens 55 may also satisfy the following condition: the abbe number of the first lens is 46.8, the abbe number of the second lens is 70, the abbe number of the third lens is 27.6, the abbe number of the fourth lens is 34.5, and the abbe number of the fifth lens is 60.3.

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

TABLE 5 structural parameters of the optical imaging lens group in the third embodiment

It should be noted that table 5 is detailed structural data of the optical imaging lens assembly of the third embodiment, wherein the units of the radius of curvature, the thickness (pitch), and the focal length are all millimeters, and the surfaces 0-12 sequentially represent the surfaces from the first side to the second side; an optical surface in the imaging plane with a radius of curvature of "infinity" is referred to as a flat surface.

Further, aspherical conic coefficients of the corresponding surfaces of the first lens 51 to the fifth lens 55 are shown in table 6 below:

TABLE 6 aspherical Cone coefficient data for different lens surfaces in example III

Surface of	K	A4	A6	A8
					2	-2.29E+01	1.77E-02	1.38E-02	-3.92E-03
3	-3.35E+00	7.14E-02	-7.15E-04	2.05E-02
					4	1.42E+02	1.91E-02	-2.17E-02	-2.81E-03
5	-2.14E+01	8.03E-02	-1.47E-01	3.92E-02
					6	-2.07E+01	-2.04E-02	2.17E-02	-3.20E-02
7	-1.59E+01	-1.83E-01	1.35E-01	-5.70E-02
					8	-3.10E+01	-4.83E-02	1.28E-01	-5.12E-02
9	2.71E+01	-1.21E-01	1.49E-01	-2.44E-02
					10	-1.85E+00	1.40E-01	-3.51E-02	-7.17E-03
11	1.57E+00	-6.07E-02	-8.11E-01	7.26E-01

Table 6 shows the aspheric coefficient data of the third embodiment, where k is the cone coefficient in the aspheric curve equation, and a4 to A8 represent the 4 th to 8 th order aspheric coefficients of each surface.

Further, through tests, when the optical imaging lens group is used for projecting image light corresponding to a scanning surface, an optical transfer function curve graph is shown in fig. 12, a field curvature distortion curve graph is shown in fig. 13, and a vertical axis chromatic aberration curve graph is shown in fig. 14; wherein, the Modulation Transfer Function (MTF) is a quantitative description of the resolution of the lens, which represents the comprehensive resolution level of an optical system, specifically a quantitative description of the sharpness (including two factors of resolution and sharpness) of the lens imaging, the field curvature distortion curve represents the F-tan (theta) distortion value (percentage) under different field angles, and the vertical axis chromatic aberration curve represents the chromatic aberration in the direction perpendicular to the axial direction.

As can be seen from fig. 12 to 14, the optical imaging lens assembly of the third embodiment has good imaging resolution and small distortion and chromatic aberration of the optical system in the full field of view, so that the optical imaging lens assembly can clearly image the scanning curved image of the optical fiber scanner, and has good imaging effect.

Example four

Fig. 15 is a schematic structural diagram of an optical imaging lens assembly according to an embodiment of the present invention. The optical imaging lens group is provided with a sixth lens 76, a first lens 71, a second lens 72, a third lens 73, a fourth lens 74 and a fifth lens 75 in sequence from a first side (i.e., the side where the diaphragm 07 is located in fig. 15) to a second side (i.e., the side where the scanning curved surface 08 is located in fig. 15) along the optical axis.

In the present embodiment, the sixth lens 76 is an additional lens outside the lens group (i.e., the first lens 71 to the fifth lens 75), it should be noted that the number of the additional lenses and other parameters (such as focal length, refractive index, dispersion system, and surface shape) may be set according to actual situations, and may be 1 or multiple additional lenses, and the number of the additional lenses and other parameters are not specifically limited herein, in the present embodiment, the number of the additional lenses is 1 (i.e., the sixth lens 76) for example, and for the other parameter settings of the sixth lens 76, the following examples of the present embodiment can be referred to, and in addition, 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 all have a gap between every two adjacent lenses, and the first lens 71, the second lens 72, the third lens 73, the first lens 73, the second lens 73, the third lens 73, and the fourth lens 76 all have a gap between every two adjacent lenses, The fourth lens 74, the fifth lens 75 and the sixth lens 76 are six single non-cemented lenses, and the optical centers of the respective lenses are located on the same straight line, that is, the optical centers of the respective lenses are located on the same main optical axis.

The focal length of the sixth lens 76 is negative, and the first side surface of the sixth lens 76 is a concave surface and the second side surface is a convex surface; the focal length of the first lens 71 is positive, and the first side surface of the first lens 71 is a concave surface and the second side surface is a convex surface; the focal length of the second lens 72 is positive, and the first side surface of the second lens 72 is a convex surface, and the second side surface is also a convex surface; the focal length of the third lens 73 is negative, and the first side surface of the third lens 73 is concave, and the second side surface is concave at the paraxial region; the focal length of the fourth lens element 74 is negative, and the first side surface of the fourth lens element 74 is convex and the second side surface is concave at paraxial region; the focal length of the fifth lens element 75 is positive, and the first side surface of the fifth lens element 75 is convex and the second side surface is concave at the paraxial region.

Alternatively, in the present embodiment, the focal lengths of the first lens 71 to the sixth lens 76 may satisfy the following relations: f. of₁F is 1.18, f₂F is 1.20, f₃F is-0.36, f₄F is-1.53, f₅F is 0.44 and f₆The value of/f is 12.19; wherein f is₁Is the focal length of the first lens 71, f₂Is the focal length of the second lens 72, f₃Is the focal length, f, of the third lens 73₄Is the focal length, f, of the fourth lens 74₅Is the focal length of the fifth lens 75, f₆Is the focal length of the sixth lens element 76, and f is the equivalent focal length of the optical imaging lens assembly.

Alternatively, in this embodiment, the refractive indexes of the first lens 71 to the sixth lens 76 may also satisfy the following condition: n1 is 1.53, n2 is 1.49, n3 is 1.65, n4 is 1.65, n5 is 1.55, and n6 is 1.59. Wherein n1 to n6 represent refractive indices of the first lens 71 to the sixth lens 76, respectively.

Alternatively, in this embodiment, the abbe numbers of the first lens 71 to the sixth lens 76 may also satisfy the following condition: the abbe number of the first lens is 65.9, the abbe number of the second lens is 70.4, the abbe number of the third lens is 33.8, the abbe number of the fourth lens is 33.8, the abbe number of the fifth lens is 64.6, and the abbe number of the sixth lens is 45.

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

TABLE 7 structural parameters of the optical imaging lens assembly of example four

Surface of	Lens serial number	Surface shape	Radius of curvature	Thickness/spacing	Refractive index of material	Coefficient of dispersion
							0	Imaging plane	Plane surface	Infinite number of elements	Infinite number of elements
1	Diaphragm 07		Infinite number of elements	1
							2	Sixth lens 76	Spherical surface	-3.60	1.00	1.59	45
3		Spherical surface	-3.33	0.17
							4	First lens 71	Aspherical surface	-5.80	1.59	1.53	65.9
5		Aspherical surface	-1.40	0.41
							6	Second lens 72	Aspherical surface	14.31	0.99	1.49	70.4
7		Aspherical surface	-1.68	0.12
							8	Third lens 73	Aspherical surface	-1.61	0.60	1.65	33.8
9		Aspherical surface	1.12	0.24
							10	Fourth lens 74	Aspherical surface	126.40	0.60	1.65	33.8
11		Aspherical surface	2.55	0.49
							12	Fifth lens 75	Aspherical surface	0.60	1.37	1.55	64.6
13		Aspherical surface	2.38	0.50
							14	Scanning curved surface 08	Spherical surface	2

It should be noted that table 7 is detailed structural data of the optical imaging lens assembly of the fourth embodiment, wherein the units of the radius of curvature, the thickness (pitch), and the focal length are all millimeters, and the surfaces 0-14 sequentially represent the surfaces from the first side to the second side; an optical surface in the imaging plane with a radius of curvature of "infinity" is referred to as a flat surface.

Further, aspherical conic coefficients of the corresponding surfaces of the first lens 71 to the sixth lens 76 are shown in table 8 below:

TABLE 8 aspherical Cone coefficient data for different lens surfaces in example four

Surface of	K	A4	A6	A8
					4	1.32E+01	-2.74E-03	4.39E-03	3.76E-03
5	-1.44E+00	4.39E-02	-1.77E-02	6.32E-03
					6	1.17E+02	2.81E-02	-1.74E-02	-1.85E-03
7	-2.62E+01	9.65E-02	-1.39E-01	3.52E-02
					8	-2.09E+01	-2.16E-02	2.24E-02	-2.07E-02
9	-8.27E+00	-1.77E-01	1.36E-01	-6.19E-02
					10	4.00E+02	-6.59E-02	1.17E-01	-4.82E-02
11	-6.71E+01	-1.15E-01	1.62E-01	-1.83E-02
					12	-1.95E+00	2.28E-01	-7.45E-02	3.59E-02
13	6.83E+00	3.58E-01	-1.04E+00	4.63E-01

Table 8 shows aspheric coefficient data in the fourth embodiment, where k is the cone coefficient in the aspheric curve equation, and a4 to A8 represent the 4 th to 8 th order aspheric coefficients of each surface.

Further, through tests, when the optical imaging lens group is used for projecting image light corresponding to a scanning surface, an optical transfer function curve graph is shown in fig. 16, a field curvature distortion curve graph is shown in fig. 17, and a vertical axis chromatic aberration curve graph is shown in fig. 18; the Modulation Transfer Function (MTF) is a quantitative description of the resolution of the lens, and represents a comprehensive resolution level of an optical system, specifically a quantitative description of the degree of sharpness (including two factors of resolution and sharpness) of the lens image, the field curvature distortion curve represents the F-tan (theta) distortion value (percentage) under different field angles, and the vertical axis chromatic aberration curve represents the chromatic aberration in the direction perpendicular to the axial direction.

As can be seen from fig. 16-18, the optical imaging lens assembly of the fourth embodiment has good imaging resolution and small distortion and chromatic aberration of the optical system in the full field of view, so that the optical imaging lens assembly can clearly image the scanning curved image of the optical fiber scanner, and has good imaging effect.

Scanning display device

The optical imaging lens group can cooperate with an optical fiber scanner (or a corresponding optical fiber scanning module) to form a scanning display device in an embodiment of the present invention (as shown in fig. 1a and 1b, the optical imaging lens group is disposed on a light emitting path of the optical fiber scanner), wherein a first side of the optical imaging lens group faces a light emitting direction of the optical fiber scanner, and a preferred mode is that the optical imaging lens group is coaxial with a central optical axis of the optical fiber scanner. Of course, reference may be made to the corresponding contents in fig. 1a and 1b for the structure and the general principle of the fiber scanner, and redundant description is omitted here.

Near-to-eye display device

The scanning display device can be further applied to near-eye display equipment, and can be matched with a near-eye display module to form the near-eye display equipment in the embodiment of the utility model to be used as head-mounted AR (augmented reality) equipment (such as AR glasses). The scanning display device is arranged in the near-eye display module.

Wherein, can include among the near-to-eye display module assembly: light source, processing control circuit, wearable frame structure, waveguide, etc. The image light beam output by the light source enters the scanning display device, and is scanned and output to the optical display mirror group by the optical fiber scanner therein, the scanning curved surface (refer to the scanning curved surface 02 in fig. 3 and the scanning curved surface 230 in fig. 2 a) of the optical fiber scanner passes through the optical display mirror group and is converted into an imaging plane (refer to the imaging plane 240 in fig. 2 a), and the imaging plane is coupled into the waveguide as the entrance pupil surface of the waveguide, and then is coupled out through waveguide expansion imaging and enters human eyes.

As another possible implementation manner, the scanning display device may further cooperate with the near-eye display module to form a near-eye display device in an embodiment of the present invention, and the near-eye display device is used as a head-mounted VR device (e.g., VR headset/glasses). The scanning display device is arranged in the near-eye display module.

In the embodiment of the utility model, the focal lengths of five lenses with the same optical axis of the optical imaging lens group are reasonably and optimally set, so that the focal power of the system can be reasonably dispersed, the aberration generated by the lenses is reduced, the aim of correcting various aberrations is fulfilled, and clear imaging of an image side curved surface is realized on the basis of improving the field angle; the refractive index, the dispersion coefficient and the surface type structure of the five lenses with the same optical axis are limited and optimized, so that the imaging quality and the field angle are further improved; the five lenses with the same optical axis are limited and optimally designed to be aspheric surface-shaped structures, so that the imaging quality is further improved, the overall structure of the optical imaging lens group is more compact, and the production requirement of miniaturization of lens products is met.

The above embodiments are only preferred embodiments of the present invention, and the embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the present invention, and all technical solutions that can be obtained by a person skilled in the art through logic analysis, reasoning or effective experiments according to the concept of the present invention should be within the scope of the present invention.

The embodiments of the present invention are described in a progressive manner, and the same and similar parts among the embodiments can be referred to each other, and each embodiment focuses on the differences from the other embodiments.

The expressions "first", "second", "said first" or "said second" used in various embodiments of the present disclosure may modify various components regardless of order and/or importance, but these expressions do not limit the respective components. The above description is only configured for the purpose of distinguishing 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, comprising, in order from a first side to a second side along an optical axis: the lens comprises a first lens with a positive focal length, a second lens with a positive focal length, a third lens with a negative focal length, a fourth lens with a negative focal length and a fifth lens with a positive focal length, wherein the optical centers of the lenses are positioned on the same straight line.

2. The optical imaging lens group of claim 1, wherein the focal lengths of the first to fifth lenses satisfy the following relationships: f1/f is more than or equal to 1.09 and less than or equal to 1.29, f2/f is more than or equal to 1.04 and less than or equal to 1.27, f3/f is more than or equal to 0.46 and less than or equal to-0.3, f4/f is more than or equal to 3.85 and less than or equal to-1.18, and f5/f is more than or equal to 0.44 and less than or equal to 0.51; wherein f1 is a focal length of the first lens element, f2 is a focal length of the second lens element, f3 is a focal length of the third lens element, f4 is a focal length of the fourth lens element, f5 is a focal length of the fifth lens element, and f is a focal length of the optical imaging lens assembly.

3. The optical imaging lens group of claim 1 or 2, wherein the refractive indices of the first to fifth lenses satisfy the following relations: n1 is more than or equal to 1.56 and less than or equal to 1.57, n2 is more than or equal to 1.49 and less than or equal to 1.53, n3 is more than or equal to 1.75 and less than or equal to 1.76, n4 is more than or equal to 1.73 and less than or equal to 1.74, and n5 is more than or equal to 1.56 and less than or equal to 1.62; wherein n1 is a refractive index of the first lens, n2 is a refractive index of the second lens, n3 is a refractive index of the third lens, n4 is a refractive index of the fourth lens, and n5 is a refractive index of the fifth lens.

4. The optical imaging lens group of claim 3, wherein the refractive index of the first to fifth lenses satisfies the following condition: the n1 is 1.56 or 1.57, the n2 is 1.49 or 1.53, the n3 is 1.75 or 1.76, the n4 is 1.73 or 1.74, and the n5 is 1.56 or 1.62.

5. The optical imaging lens group of claim 4, wherein the abbe number of the first lens element to the fifth lens element satisfies the following relations: v1 is more than or equal to 43.5 and less than or equal to 46.8, v2 is more than or equal to 65.9 and less than or equal to 70, v3 is more than or equal to 27.5 and less than or equal to 27.6, v4 is more than or equal to 34.5 and less than or equal to 44.9, and v5 is more than or equal to 60.3 and less than or equal to 63.9; 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.

6. The optical imaging lens group of claim 5, wherein the abbe number of the first lens element to the fifth lens element satisfies the following condition: the abbe number of the first lens is 43.5 or 46.8, the abbe number of the second lens is 65.9 or 70, the abbe number of the third lens is 27.5 or 27.6, the abbe number of the fourth lens is 34.5 or 44.9, and the abbe number of the fifth lens is 60.3 or 63.9.

7. The optical imaging lens assembly of any one of claims 1 to 6, wherein the first side surface of the first lens element is concave or convex, and the second side surface of the first lens element is convex; the first side surface and the second side surface of the second lens are convex surfaces; the first side surface of the third lens is concave, and the second side surface of the third lens is concave at a paraxial region; the first side surface of the fourth lens is a concave surface, and the second side surface of the fourth lens is a concave surface or a convex surface; the first side surface of the fifth lens element is convex and the second side surface of the fifth lens element is concave at a paraxial region.

8. The optical imaging lens group of claim 7, wherein the first side surface and the second side surface of the first lens element to the fifth lens element are aspheric 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.

9. A scanning display device, comprising an optical fiber scanner and the optical imaging lens group of any one of the preceding claims 1 to 8, wherein the optical fiber scanner is used for scanning and emitting light of an image to be displayed, and the optical imaging lens group is used for magnifying, imaging and projecting a scanning surface corresponding to the light emitted by the optical fiber scanner;

10. A near-eye display device, wherein the near-eye display device is used as a head-mounted augmented reality device or a head-mounted virtual reality device, and comprises at least a near-eye display module and the scanning display device according to claim 9, and the scanning display device is disposed in the near-eye display module.