Optical imaging lens group and scanning display device

Abstract

The utility model discloses an optical imaging lens group and a scanning display device, and relates to the technical field of scanning display. The optical imaging lens group provided by the utility model comprises a first lens, a second lens, a third lens and a fourth lens which are sequentially arranged along a common optical axis from a first side to a second side, wherein the first side is arranged opposite to a light emitting end of an optical fiber scanner; the focal power of the first lens, the second lens and the third lens is positive, the focal power of the fourth lens is positive or negative, the image side surface of the first lens is a convex surface, the object side surface of the second lens is a concave surface, the third lens is a biconvex lens, the fourth lens is a meniscus lens and is bent towards the second side, the image side surface of the fourth lens is a convex surface, and the object side surface of the fourth lens is a concave surface.

Description

Technical Field

[0001] This application relates to the field of scanning display technology, specifically to an optical imaging lens assembly and a scanning display device. Background Technology

[0002] Scanning display imaging, as an emerging display technology, can be used in various application scenarios such as projection display and near-eye display.

[0003] However, when scanning units are applied to near-eye display devices, such as AR display devices, the exit pupil distance of the lens assemblies currently adapted to fiber optic scanners is relatively large. This causes a mismatch between the light projected by the scanning unit and the coupling area of ​​the waveguide, affecting image quality. In addition, current lens assemblies have a large number of lenses, resulting in a large overall size and weight. Utility Model Content

[0004] The purpose of this application is to provide an optical imaging lens assembly and a scanning display device to meet the requirements.

[0005] Another objective of this application is to provide an application of a scanning display device configured for use in the field of near-eye display devices, which features high imaging quality, miniaturization, and lightweight design.

[0006] This application provides an optical imaging lens assembly, including a first lens, a second lens, a third lens, and a fourth lens arranged coaxially along a first side to a second side, wherein the first side is opposite to the light-emitting end of a fiber optic scanner; wherein the optical powers of the first lens to the third lens are positive, negative, and positive, respectively, and the optical power of the fourth lens is positive or negative; the image-side surface of the first lens is convex, the object-side surface of the second lens is concave, the third lens is a biconvex lens, and the fourth lens is a meniscus lens bent towards the second side, wherein the image-side surface of the fourth lens is convex and the object-side surface is concave.

[0007] Furthermore, both the first lens and the fourth lens are aspherical lenses.

[0008] Furthermore, at least one of the second lens and the third lens is an aspherical lens.

[0009] Furthermore, the ratio of the focal length of the first lens to the total focal length of the optical imaging lens group is in the range of 1.07 to 1.76; the ratio of the focal length of the second lens to the total focal length of the optical imaging lens group is in the range of -1.23 to -0.62; the ratio of the focal length of the third lens to the total focal length of the optical imaging lens group is in the range of 0.53 to 1.37; and the ratio of the focal length of the fourth lens to the total focal length of the optical imaging lens group is in the range of -11.99 to 2.63.

[0010] Furthermore, the refractive index of the first lens is in the range of 1.5 to 1.6, and the Abbe number is in the range of 35.6 to 81.6; the refractive index of the second lens is in the range of 1.64 to 1.85, and the Abbe number is in the range of 21.2 to 31.3; the refractive index of the third lens is in the range of 1.5 to 1.8, and the Abbe number is in the range of 49.2 to 81.3; and the refractive index of the fourth lens is in the range of 1.7 to 1.8, and the Abbe number is in the range of 34.4 to 49.3.

[0011] Furthermore, the exit pupil distance of the optical imaging lens group is greater than 5mm.

[0012] Furthermore, the optical imaging lens group satisfies the following conditions: focal length range of 2.66mm~2.75mm, field of view of 20 degrees, and aperture coefficient range of 1.62~1.67.

[0013] Furthermore, the height of the zero-axis ray relative to the optical axis at the image plane side of any one of the first lens, the second lens, the third lens, and the fourth lens is greater than the height of the zero-axis ray relative to the optical axis at the object plane side of the lens.

[0014] This application also provides a scanning display device, including a fiber optic scanner, the aforementioned optical imaging lens group and galvanometer, wherein the scanning fiber of the fiber optic scanner vibrates in one direction under the drive of a driving signal and forms a linear scanning trajectory, which, after passing through the optical imaging lens group, forms an image under the action of the galvanometer.

[0015] This application also provides an application of the scanning display device as described above, comprising: configuring the scanning display device in a near-eye display device.

[0016] The technical solutions adopted in this application embodiment can achieve the following technical effects: the optical imaging lens group, through the configuration of factors such as the number of lenses, the surface structure of each lens, and the distribution of positive and negative optical power, enables the optical imaging lens group to have a longer exit pupil distance, so that the reflecting mirror and galvanometer assembly can be placed between the waveguide and the optical imaging lens group, making it miniaturized and lightweight; at the same time, it can also position the exit pupil of the scanning display device in the X direction at the coupling region of the waveguide lens and position the exit pupil of the scanning display device in the Y direction at the galvanometer assembly, thereby ensuring that the beam emitted by the scanning display device has less beam separation when it reaches the coupling region of the waveguide lens, thereby improving the light energy utilization rate and ensuring the imaging quality.

[0017] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the technical solutions of this application. The objectives and other advantages of this application may be realized and obtained by means of the structures and / or processes particularly pointed out in the description, claims and drawings. Attached Figure Description

[0018] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0019] Figure 1a , 1b This is an illustrative structural diagram of a scanning display system;

[0020] Figure 2 This is a schematic diagram of the scanning output of the fiber optic scanner provided in an embodiment of this application;

[0021] Figure 3 This is a schematic diagram of a scanning display device provided in an embodiment of this application;

[0022] Figure 4 This is a schematic diagram of the optical path of a scanning display device applied to a near-eye display device, provided in an embodiment of this application.

[0023] Figure 5 This is a schematic diagram of the optical path of an optical imaging lens group with a short exit pupil distance provided in an embodiment of this application applied to a near-eye display device;

[0024] Figure 6 This is a schematic diagram of the optical path of an optical imaging lens group with a long exit pupil distance provided in an embodiment of this application applied to a near-eye display device;

[0025] Figure 7 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 1 of this application;

[0026] Figure 8 This is the MTF curve of the optical imaging lens group in Embodiment 1 of this application;

[0027] Figure 9 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 1 of this application;

[0028] Figure 10 This is the transverse chromatic aberration diagram of the optical imaging lens group in Embodiment 1 of this application;

[0029] Figure 11 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 2 of this application;

[0030] Figure 12This is the MTF curve of the optical imaging lens group in Embodiment 2 of this application;

[0031] Figure 13 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 2 of this application;

[0032] Figure 14 This is the transverse chromatic aberration diagram of the optical imaging lens group in Embodiment 2 of this application;

[0033] Figure 15 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 3 of this application;

[0034] Figure 16 This is the MTF curve of the optical imaging lens group in Embodiment 3 of this application;

[0035] Figure 17 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 3 of this application;

[0036] Figure 18 This is the transverse chromatic aberration diagram of the optical imaging lens group in Embodiment 3 of this application;

[0037] Figure 19 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 4 of this application;

[0038] Figure 20 This is the MTF curve of the optical imaging lens group in Embodiment 4 of this application;

[0039] Figure 21 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 4 of this application;

[0040] Figure 22 This is the transverse chromatic aberration diagram of the optical imaging lens group in Embodiment 4 of this application;

[0041] Figure 23 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 5 of this application;

[0042] Figure 24 This is the MTF curve of the optical imaging lens group in Embodiment 5 of this application;

[0043] Figure 25 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 5 of this application;

[0044] Figure 26 This is the chromatic aberration diagram of the optical imaging lens group in Embodiment 5 of this application.

[0045] Figure 27 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment Six of this application;

[0046] Figure 28 This is the MTF curve of the optical imaging lens group in Embodiment Six of this application;

[0047] Figure 29 This is a field curvature distortion curve of the optical imaging lens group in Embodiment Six of this application;

[0048] Figure 30 This is the chromatic aberration diagram of the optical imaging lens group in Embodiment Six of this application. Detailed Implementation

[0049] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0050] Explanatory Scanning Display System

[0051] Current scanning display imaging can be achieved using either a Digital Micromirror Device (DMD) or a Fiber Scanning Display (FSD) device. The FSD approach, as a novel scanning display imaging method, uses a fiber optic scanner to achieve image scanning output. To enable those skilled in the art to clearly understand the present application, a brief explanation of the principles and corresponding system of fiber optic scanning imaging is provided below.

[0052] To provide a clearer explanation of the scanning display system, this manual provides the following: Figure 1a An illustrative scanning display system is shown, which mainly includes:

[0053] The system includes a processor 100, a laser assembly 110, an optical fiber scanning module 120, a transmission optical fiber 130, a light source modulation circuit 140, a scanning drive circuit 150, and a beam combining unit 160.

[0054] The processor 100 can be a graphics processing unit (GPU), a central processing unit (CPU), or other chips or circuits with control and image processing functions, without being specifically limited here.

[0055] When the system is in operation, the processor 100 controls the light source modulation circuit 140 to modulate the laser group 110 according to the image data to be displayed. The laser group 110 contains multiple monochromatic lasers, each emitting a beam of a different color. As shown in Figure 1, the laser group can specifically use red (R), green (G), and blue (B) lasers. The beams emitted by each laser in the laser group 110 are combined into a single laser beam by the beam combining unit 160 and coupled into the transmission optical fiber 130.

[0056] The processor 100 can also control the scanning drive circuit 150 to drive the fiber scanner in the fiber scanning module 120 to perform scanning, thereby scanning and outputting the beam transmitted in the transmission fiber 130.

[0057] 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.

[0058] 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 , 1bThe 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.

[0059] like Figure 2 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 imaging is on a planar carrier, the image is a plane. It should be noted that in other embodiments of this application, the image formed after passing through the lens group 123 can correspond to the surface of the imaging carrier, that is, it can change with the shape of the carrier surface, as long as the image is clear).

[0060] Please refer to Figure 3 This specification provides a scanning display device, which includes a fiber optic scanner 31, an optical imaging lens group 32, and a galvanometer assembly 33.

[0061] The fiber optic scanner 31 mainly includes a fiber optic actuator 311 and an optical fiber 322. The fiber optic actuator 311 is connected to the optical fiber 312. Under the drive of an external signal, the fiber optic actuator 311 moves the optical fiber 312 on a first plane (e.g., Figure 3 The XZ plane in the coordinate system shown vibrates and scans at a first operating frequency to form a linear scanning trajectory, and the beam of the linear scanning trajectory enters the optical imaging lens group 23. It should be noted that the specific structure of the fiber optic scanner 31 here can refer to the fiber optic scanning module 120 described above. The biggest difference between it and the fiber optic scanning module 120 is that in this embodiment, the fiber optic scanner 31 can be equipped with only one set of actuators or only one set of actuators can work in its working state, so as to realize the fiber optic scanner to perform one-dimensional scanning.

[0062] The optical imaging lens assembly 32 is located between the fiber optic scanner 31 and the galvanometer assembly 33. It should be noted that the side of the optical imaging lens assembly 32 opposite to the fiber optic scanner 31 is the first side, and the side opposite to the galvanometer assembly 33 is the second side. At least one light-incident surface (also referred to as the first side) of the optical imaging lens assembly 32 faces the light-emitting end of the fiber optic cable. Light emitted from the light-emitting surface (also referred to as the second side) of the optical imaging lens assembly 32 is projected onto the galvanometer assembly directly or indirectly. It should be noted that the direct projection of light emitted from the light-emitting surface of the optical imaging lens assembly 32 onto the galvanometer assembly 33 can be understood as the light-emitting surface of the optical imaging lens assembly 32 facing the galvanometer assembly; in this case, the light emitted from the light-emitting surface of the optical imaging lens assembly 32 can be directly projected onto the galvanometer assembly 33. The light emitted from the light-emitting surface of the aforementioned optical imaging lens group 32 is indirectly projected onto the galvanometer assembly 33. This can be understood as the optical imaging lens group 32 and the galvanometer assembly 33 being connected by an optical element (e.g., a reflector) that alters the light path, so that the light emitted from the light-emitting surface of the optical imaging lens group 32 is projected onto the optical element before entering the galvanometer assembly 33.

[0063] One side of the galvanometer assembly 33 is a reflective surface, which is tilted relative to the optical axis of the optical imaging mirror group 32. Under external drive, it can rotate and vibrate at a second operating frequency around the axis of the first plane or parallel to the axis of the first plane, projecting and reflecting the light emitted from the optical imaging mirror group 32 onto a preset area to form an image. The scanning trajectory of the fiber optic scanner 31 and the scanning trajectory of the galvanometer assembly 33 correspond to the rows and columns on the image.

[0064] The scanning display device 300 provided in the above embodiments of this specification can achieve decoupling of fast-axis and slow-axis vibration. The fiber optic fast-axis drive can directly use the resonant frequency drive, eliminating the need to design complex matching relationships between the fiber optic characteristic frequency, the fiber optic actuator characteristic frequency, and the drive frequency, thus avoiding nonlinearity. Fast-axis scanning is achieved with extremely low drive voltage. This greatly increases the robustness of device parameters and significantly reduces manufacturing requirements. Furthermore, when the fiber optic actuator uses piezoelectric one-dimensional high-frequency scanning, the high-frequency vibration component has extremely low vibration inertia. Compared to MEMS high-frequency mirrors, this reduces processing requirements, lowers drive power consumption, and improves fatigue resistance.

[0065] like Figure 3 When the scanning display device 300 shown is applied to near-eye display devices, AR glasses are used as an example. Please refer to [reference needed]. Figure 4A reflector 34 is provided on the light-emitting path of the optical imaging lens assembly. A galvanometer assembly 33 is located opposite a reflective surface of the reflector 34, with one side of the galvanometer assembly 33 abutting against the coupling region 41 of the waveguide lens. The light beam emitted from the light-emitting surface of the optical imaging lens assembly changes its optical path after passing through the reflective surface of the reflector 34, and then enters the reflective surface of the galvanometer assembly 33, where it enters the coupling region 41 of the waveguide lens. To ensure the imaging quality of the near-eye display device, the light convergence point of the scanning display device 300 needs to be located at the galvanometer assembly 33 or between the galvanometer assembly 33 and the coupling region of the waveguide, so that the light beam projected by the scanning display device 300 can more fully enter the coupling region 41 of the waveguide lens.

[0066] Figure 5 The optical imaging lens assembly with a short exit pupil distance provided in the embodiments of this specification is currently used in scanning display devices. The distance between the light convergence point and the light exit surface of the optical imaging lens assembly (i.e., the exit pupil distance) is relatively short, resulting in a mismatch between it and the coupling region 41 of the waveguide lens, causing discontinuous images to be presented. In addition, traditional optical imaging lens assemblies have a large number of lenses and a large volume, resulting in an increase in the overall size of the scanning display device.

[0067] Based on this, the embodiments of this specification provide an adapter. Figure 3 The optical imaging lens group of the scanning display device shown.

[0068] Optical imaging lens group

[0069] The optical imaging lens assembly in this embodiment consists of a first lens, a second lens, a third lens, and a fourth lens arranged coaxially from a first side to a second side, with the second side corresponding to the light-emitting end of the fiber optic scanner. The optical powers of the first to third lenses are positive, negative, and positive, respectively, while the optical power of the fourth lens is either positive or negative. Further, the image-side surface of the first lens is convex, and the object-side surface can be flat, convex, or concave; the object-side surface of the second lens is concave, and the image-side surface can be flat, convex, or concave; the third lens is a biconvex lens; and the fourth lens is a meniscus lens bent towards the second side, wherein the object-side surface of the fourth lens is concave, and the image-side surface is convex. In this embodiment, the object-side surface is the side of the lens facing the light-emitting end of the fiber optic scanner, and the image-side surface is the side of the lens away from the light-emitting end of the fiber optic scanner. In this embodiment, by reasonably optimizing the positive and negative focal lengths of the four coaxial lenses in the optical imaging lens assembly, the optical power of the system can be reasonably dispersed, aberrations caused by the lenses can be reduced, and clear imaging can be achieved. Furthermore, optical imaging lens assemblies with longer exit pupil distances typically have larger light divergence angles. Here, the image-side surface of the first lens is made convex, which reduces the height of the light rays passing through this surface relative to the optical axis, thus reducing the size of the optical imaging lens assembly. The object-side surface of the second lens is concave, and the third lens is a biconvex lens, which can eliminate field curvature and astigmatism during the imaging process. The second side corresponds to the light-emitting end of the fiber optic scanner. The fiber optic cable (cantilever fiber) of the fiber optic scanner scans along a specific direction to form a linear scanning trajectory. Here, the object-side surface of the fourth lens is made concave, which allows the fourth lens to adapt well to the linear scanning trajectory, facilitating the reception of light from a wide viewing angle, thereby enabling more comprehensive and sufficient acquisition of information from the linear scanning trajectory. In addition, the optical imaging lens assembly has a smaller number of lenses, which reduces the size of the assembly, thus meeting the requirements for miniaturization and lightweighting of near-eye display devices. It should be noted that in this application, the direction of the optical axis extending from the second side to the first side is considered the positive direction, and the direction of the optical axis extending from the first side to the second side is considered the negative direction.

[0070] Furthermore, both the first and second lenses are aspherical lenses.

[0071] It should be noted that aspherical lenses are preferred for both the first and second lenses. In some embodiments, spherical lenses can also be used for the first lens, such as in Embodiment Six.

[0072] More preferably, at least one of the third and fourth lenses is an aspherical lens. For example, the third lens is a spherical lens and the fourth lens is an aspherical lens. Another example is that the third lens is an aspherical lens and the fourth lens is a spherical lens. Yet another example is that both the third and fourth lenses are aspherical lenses.

[0073] Furthermore, the ratio of the focal length of the first lens to the total focal length of the optical imaging lens group is in the range of 1.07 to 1.76; the ratio of the focal length of the second lens to the total focal length of the optical imaging lens group is in the range of -1.23 to -0.62; the ratio of the focal length of the third lens to the total focal length of the optical imaging lens group is in the range of 0.53 to 1.37; and the ratio of the focal length of the fourth lens to the total focal length of the optical imaging lens group is in the range of -11.99 to 2.63. It should be noted that by limiting the ratio of the focal length of each lens to the total focal length of the lens group, the optical power of each lens is reasonably distributed, which is beneficial for aberration correction.

[0074] Furthermore, the refractive index of the first lens L1 is in the range of 1.5 to 1.6, and the Abbe number is in the range of 35.6 to 81.6; the refractive index of the second lens L2 is in the range of 1.64 to 1.85, and the Abbe number is in the range of 21.2 to 31.3; the refractive index of the third lens L3 is in the range of 1.5 to 1.8, and the Abbe number is in the range of 49.2 to 81.3; and the refractive index of the fourth lens L4 is in the range of 1.7 to 1.8, and the Abbe number is in the range of 34.4 to 49.3.

[0075] Furthermore, the optical imaging lens assembly meets the following conditions: the exit pupil distance of the optical imaging lens assembly is greater than 5mm, the focal length range is 2.66mm to 2.75mm, the field of view is 20 degrees, and the aperture coefficient range is 1.62 to 1.67. The optical imaging lens assembly provided in this application has a long exit pupil distance, which can meet the placement of the galvanometer assembly and optical elements (reflectors) in the scanning display device. At the same time, the image beam ultimately projected by the scanning display device can also match the coupling area of ​​the waveguide of the AR glasses, ensuring the final imaging quality.

[0076] Furthermore, the height of the zero-axis ray relative to the optical axis at the image plane side of any one of the first, second, third, and fourth lenses is greater than the height of the zero-axis ray relative to the optical axis at the object plane side of the lens. It should be noted that this arrangement makes the overall structure of the optical imaging lens group more similar to a concentric lens group, making the object plane appear to converge at the center of the sphere of this concentric lens group, which is beneficial for correcting spherical aberration. In addition, this arrangement minimizes the overall length and volume of the optical imaging lens group, facilitating its miniaturization and weight reduction.

[0077] To describe the technical effects of the aforementioned optical imaging lens assembly, specific examples are provided below. Figure 6 This is a schematic diagram of the optical path of an optical imaging lens assembly provided in the embodiments of this specification applied to a near-eye display device. For example... Figure 6As shown, the optical imaging lens group has a long exit pupil distance, which allows the reflector and galvanometer assembly to be placed between the waveguide and the optical imaging lens group. At the same time, the exit pupil position of the scanning display device in the X direction is located in the coupling region of the waveguide lens, and the exit pupil position of the scanning display device in the Y direction is located at the galvanometer assembly. This ensures that the beam emitted by the scanning display device has less beam separation when it reaches the coupling region of the waveguide lens, thereby improving the light energy utilization rate and ensuring the imaging quality.

[0078] Furthermore, in one possible implementation, the connection between multiple lenses can be achieved by spacing or by adhesive bonding, depending on the specific application requirements, and no limitation is imposed here.

[0079] Alternatively, in one possible implementation, multiple lenses are made of either plastic or glass. It should be noted that lenses made of plastic can effectively reduce production costs. Compared to glass, the cost of plastic lenses is one-twentieth to one-tenth of that of glass lenses, making them highly advantageous for low-cost mass production. Furthermore, plastic lenses are typically injection molded, which is easy to process and can be readily fabricated into various aspherical surface structures. Plastic also reduces the overall weight of the lens, facilitating lightweight product design. When using glass, its higher and wider refractive index offers advantages in correcting lens aberrations. Glass also has a much lower coefficient of thermal expansion, which is beneficial for precision assembly. Additionally, glass's inherent resistance to high temperatures, ultraviolet radiation, and acids and alkalis provides significant advantages in terms of lens lifespan and performance stability. It should be emphasized that other embodiments of the present invention are not limited to the plastic and glass materials provided in this specification; other materials suitable for lens fabrication can also be used.

[0080] Example 1

[0081] Figure 7 This is a schematic diagram of an optical imaging lens assembly provided in Embodiment 1. The optical imaging lens assembly includes four lenses arranged sequentially along the optical axis: a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4, arranged coaxially from the first side to the second side. The focal lengths of the first lens L1 to the fourth lens L4 are positive, negative, positive, and negative, respectively. Further, the image-side surface of the first lens L1 is convex, and the object-side surface is concave. The image-side surface of the second lens L2 is convex, and the object-side surface is concave. The third lens L3 is a biconvex lens. The fourth lens L4 is a meniscus lens bent towards the second side, with a convex image-side surface and a concave object-side surface. It should be noted that the surface structure of some lenses in this embodiment is not limited to that shown in the figure. For example, the object-side surface of the first lens L1 can also be planar or convex, and the image-side surface of the second lens L2 can also be planar or concave.

[0082] Furthermore, in this embodiment, the second side of the optical imaging lens group corresponds to the linear scanning trajectory at the light source end. The total focal length of the optical imaging lens group is 2.75mm, the aperture F / # is 1.67, the exit pupil distance is 7.4mm, and the full field of view is 20 degrees.

[0083] The relationship between the focal length of each lens and the total focal length of the lens in this embodiment is shown in Table 1:

[0084] Table 1 shows the relationship between the focal length of each lens element and the total focal length of the lens in this embodiment.

[0085]

[0086] Furthermore, in the embodiments of this specification, the preferred parameters for the radius of curvature, thickness, refractive index, and Abbe number of each lens in the optical imaging lens group are shown in Table 2:

[0087] Table 2 Structural parameters of the optical imaging lens assembly in Example 1

[0088]

[0089] It should be noted that Table 2 contains detailed structural data of the optical imaging lens group in Embodiment 1. The units for radius of curvature, thickness and focal length are all millimeters, and the order of surfaces S1-8 indicates the surfaces from the first side to the second side; the optical surface with radius of curvature "Infinity" refers to a plane.

[0090] The conic and aspherical coefficients of the aspherical surfaces of each lens in the optical imaging lens assembly are shown in Table 3. Table 3: Conic and aspherical coefficients of the aspherical surfaces of each lens in the optical imaging lens assembly in Example 1.

[0091]

[0092] It should be noted that the order of the conic coefficient and aspherical coefficient from top to bottom in this specification corresponds to the aspherical surfaces distributed sequentially from the first side to the second side in the optical imaging lens group, and will not be described again in other embodiments of the specification.

[0093] 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 8 As shown, the field distortion curve is as follows: Figure 9 As shown, the vertical axis color difference curve is as follows: Figure 10As shown; among them, the optical transfer function (MTF) curve represents the overall resolution level of an optical system, the field curvature distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the transverse chromatic aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axis.

[0094] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element may be located on the first side of the optical imaging lens assembly, and the optical imaging lens assembly may be installed inside the housing.

[0095] Example 2

[0096] Figure 11 This is a schematic diagram of an optical imaging lens assembly provided in Embodiment 2. The optical imaging lens assembly includes four lenses arranged sequentially along the optical axis: a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4, arranged coaxially from the first side to the second side. The focal lengths of the first lens L1 to the fourth lens L4 are positive, negative, positive, and negative, respectively. Further, the image-side and object-side surfaces of the first lens L1 are both convex. The image-side surface of the second lens L2 is convex, and the object-side surface is concave. The third lens L3 is a biconvex lens. The fourth lens L4 is a meniscus lens bent towards the second side, with a convex image-side surface and a concave object-side surface. It should be noted that the surface structure of some lenses in this embodiment is not limited to that shown in the figure. For example, the object-side surface of the first lens L1 in this embodiment can also be planar or concave, and the image-side surface of the second lens L2 can also be planar or concave.

[0097] Furthermore, in this embodiment, the second side of the optical imaging lens group corresponds to the linear scanning trajectory at the light source end. The total focal length of the optical imaging lens group is 2.68mm, the aperture F / # is 1.66, the exit pupil distance is 7.4mm, and the full field of view is 20 degrees.

[0098] The relationship between the focal length of each lens and the total focal length of the lens in this embodiment is shown in Table 4:

[0099] Table 4. Relationship between focal length of each lens element and total focal length of the lens in Example 2.

[0100]

[0101] Furthermore, in the embodiments of this specification, the preferred parameters for the radius of curvature, thickness, refractive index, and Abbe number of each lens in the optical imaging lens group are shown in Table 5:

[0102] Table 5 Structural parameters of the optical imaging lens assembly in Example 2

[0103]

[0104] It should be noted that Table 5 contains detailed structural data of the optical imaging lens group in Embodiment 2. The units for radius of curvature, thickness and focal length are all millimeters, and the order of surfaces S1-8 indicates the surfaces from the first side to the second side; the optical surface with radius of curvature "Infinity" refers to a flat surface.

[0105] The conic and aspherical coefficients of the aspherical surfaces of each lens in the optical imaging lens assembly are shown in Table 6. Table 6: Conic and Aspherical Coefficients of the Aspherical Surfaces of Each Lens in the Optical Imaging Lens Assembly in Example 2

[0106]

[0107] Furthermore, tests showed that when the image light corresponding to the scanning surface is projected using the aforementioned optical imaging lens group, its optical transfer function curve is as follows: Figure 12 As shown, the field distortion curve is as follows: Figure 13 As shown, the vertical axis color difference curve is as follows: Figure 14 As shown; among them, the optical transfer function (MTF) curve represents the overall resolution level of an optical system, the field curvature distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the transverse chromatic aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axis.

[0108] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element may be located on the first side of the optical imaging lens assembly, and the optical imaging lens assembly may be installed inside the housing.

[0109] Example 3

[0110] Figure 15 This is a schematic diagram of an optical imaging lens assembly provided in Embodiment 3. The optical imaging lens assembly includes four lenses arranged sequentially along the optical axis: a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4, arranged coaxially from the first side to the second side. The focal lengths of the first lens L1 to the fourth lens L4 are positive, negative, positive, and negative, respectively. Further, the image-side and object-side surfaces of the first lens L1 are both convex. The image-side surface of the second lens L2 is convex, and the object-side surface is concave. The third lens L3 is a biconvex lens. The fourth lens L4 is a meniscus lens bent towards the second side, with a convex image-side surface and a concave object-side surface. In this embodiment, the surface structure of some lenses is not limited to that shown in the figure. For example, the object-side surface of the first lens L1 can also be flat or concave, and the image-side surface of the second lens L2 can also be flat or concave.

[0111] Furthermore, in this embodiment, the second side of the optical imaging lens group corresponds to the linear scanning trajectory at the light source end. The total focal length of the optical imaging lens group is 2.66mm, the aperture F / # is 1.62, the exit pupil distance is 7.4mm, and the full field of view is 20 degrees.

[0112] The relationship between the focal length of each lens and the total focal length of the lens in this embodiment is shown in Table 7:

[0113] Table 7. Relationship between focal length of each lens element and total focal length of the lens in Example 3.

[0114]

[0115] Furthermore, in the embodiments of this specification, the preferred parameters for the radius of curvature, thickness, refractive index, and Abbe number of each lens in the optical imaging lens group are shown in Table 8:

[0116] Table 8 Structural parameters of the optical imaging lens assembly in Example 3

[0117]

[0118]

[0119] It should be noted that Table 8 contains detailed structural data of the optical imaging lens group in Embodiment 3. The units for radius of curvature, thickness and focal length are all millimeters, and the order of surfaces S1-8 indicates the surfaces from the first side to the second side; the optical surface with radius of curvature "Infinity" refers to a plane.

[0120] The conic and aspherical coefficients of the aspherical surfaces of each lens in the optical imaging lens assembly are shown in Table 9. Table 9: Conic and Aspherical Coefficients of the Aspherical Surfaces of Each Lens in the Optical Imaging Lens Assembly in Example 3

[0121]

[0122] 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 16 As shown, the field distortion curve is as follows: Figure 17 As shown, the vertical axis color difference curve is as follows: Figure 18 As shown; among them, the optical transfer function (MTF) curve represents the overall resolution level of an optical system, the field curvature distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the transverse chromatic aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axis.

[0123] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element may be located on the first side of the optical imaging lens assembly, and the optical imaging lens assembly may be installed inside the housing.

[0124] Example 4

[0125] Figure 19 This is a schematic diagram of an optical imaging lens assembly provided in Embodiment 4. The optical imaging lens assembly includes four lenses arranged sequentially along the optical axis: a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4, arranged coaxially from the first side to the second side. The focal lengths of the first lens L1 to the fourth lens L4 are positive, negative, positive, and negative, respectively. Further, the image-side surface of the first lens L1 is convex, and the object-side surface is concave. The image-side surface of the second lens L2 is convex, and the object-side surface is concave. The third lens L3 is a biconvex lens. The fourth lens L4 is a meniscus lens bent towards the second side, with a convex image-side surface and a concave object-side surface. In this embodiment, the surface structure of some lenses is not limited to that shown in the figure. For example, the object-side surface of the first lens L1 can also be planar or convex, and the image-side surface of the second lens L2 can also be planar or concave.

[0126] Furthermore, in this embodiment, the second side of the optical imaging lens group corresponds to the linear scanning trajectory of the light source end. The total focal length of the optical imaging lens group is 2.7mm, the aperture F / # is 1.69, the exit pupil distance is 8.2mm, and the full field of view is 20 degrees.

[0127] In this embodiment, the relationship parameters between the focal length of each lens and the total focal length of the lens are shown in Table 10:

[0128] Table 10 shows the relationship between the focal length of each lens element and the total focal length of the lens in Example 4.

[0129]

[0130] Furthermore, in the embodiments of this specification, the preferred parameters for the radius of curvature, thickness, refractive index, and Abbe number of each lens in the optical imaging lens group are shown in Table 11:

[0131] Table 11 Structural parameters of the optical imaging lens assembly in Example 4

[0132]

[0133]

[0134] It should be noted that Table 11 contains detailed structural data of the optical imaging lens group in Embodiment 4. The units for radius of curvature, thickness and focal length are all millimeters, and the order of surfaces S1-8 indicates the surfaces from the first side to the second side; the optical surface with radius of curvature "Infinity" refers to a flat surface.

[0135] The conicity and asphericity of the aspherical surfaces of each lens in the optical imaging lens group of this embodiment are shown in Table 12.

[0136] Table 12. Conicity and asphericity of each lens in the optical imaging lens assembly of Example 4.

[0137]

[0138] 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 optical transfer function (MTF) curve represents the overall resolution level of an optical system, the field curvature distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the transverse chromatic aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axis.

[0139] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element may be located on the first side of the optical imaging lens assembly, and the optical imaging lens assembly may be installed inside the housing.

[0140] Example 5

[0141] Figure 23 This is a schematic diagram of an optical imaging lens assembly provided in Embodiment 5. The optical imaging lens assembly includes four lenses arranged sequentially along the optical axis: a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4, arranged coaxially from the first side to the second side. The focal lengths of the first lens L1 to the fourth lens L4 are positive, negative, positive, and positive, respectively. Further, the image-side surface of the first lens L1 is convex, and the object-side surface is concave. The image-side surface of the second lens L2 is convex, and the object-side surface is concave. The third lens L3 is a biconvex lens. The fourth lens L4 is a meniscus lens bent towards the second side, with a convex image-side surface and a concave object-side surface. It should be noted that the surface structure of some lenses in this embodiment is not limited to that shown in the figure. For example, the object-side surface of the first lens L1 can also be planar or convex, and the image-side surface of the second lens L2 can also be planar or concave.

[0142] Furthermore, in this embodiment, the second side of the optical imaging lens group corresponds to the linear scanning trajectory at the light source end. The total focal length of the optical imaging lens group is 2.65mm, the aperture F / # is 1.67, the exit pupil distance is 9mm, and the full field of view is 20 degrees.

[0143] The relationship between the focal length of each lens and the total focal length of the lens in this embodiment is shown in Table 13:

[0144] Table 13 shows the relationship between the focal length of each lens element and the total focal length of the lens in Example 5.

[0145]

[0146] Furthermore, in the embodiments of this specification, the preferred parameters for the radius of curvature, thickness, refractive index, and Abbe number of each lens in the optical imaging lens group are shown in Table 14:

[0147] Table 14 Structural parameters of the optical imaging lens assembly in Example 5

[0148]

[0149] It should be noted that Table 14 contains detailed structural data of the optical imaging lens assembly of Example 5. The units for radius of curvature, thickness and focal length are all millimeters, and the order of surfaces S1-8 indicates the surfaces from the first side to the second side; the optical surface with radius of curvature "Infinity" refers to a flat surface.

[0150] The conic and aspherical coefficients of the aspherical surfaces of each lens in the optical imaging lens assembly are shown in Table 6. Table 15 shows the conic and aspherical coefficients of the aspherical surfaces of each lens in the optical imaging lens assembly in Example 5.

[0151]

[0152] 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 24 As shown, the field distortion curve is as follows: Figure 25 As shown, the vertical axis color difference curve is as follows: Figure 26 As shown; among them, the optical transfer function (MTF) curve represents the overall resolution level of an optical system, the field curvature distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the transverse chromatic aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axis.

[0153] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element may be located on the first side of the optical imaging lens assembly, and the optical imaging lens assembly may be installed inside the housing.

[0154] Example 6

[0155] Figure 27This is a schematic diagram of an optical imaging lens assembly provided in Embodiment Six. The optical imaging lens assembly includes four lenses arranged sequentially along the optical axis: a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4, arranged coaxially from the first side to the second side. The focal lengths of the first lens L1 to the fourth lens L4 are positive, negative, positive, and positive, respectively. Further, the image-side surface of the first lens L1 is convex, and the object-side surface is concave. The second lens L2 is a biconcave lens, and the third lens L3 is a biconvex lens. The fourth lens L4 is a meniscus lens bent towards the second side, with a convex image-side surface and a concave object-side surface. It should be noted that the surface structure of some lenses in this embodiment is not limited to that shown in the figure. For example, the object-side surface of the first lens L1 can also be planar or convex, and the image-side surface of the second lens L2 can also be planar or convex.

[0156] Furthermore, in this embodiment, the second side of the optical imaging lens group corresponds to the linear scanning trajectory at the light source end. The total focal length of the optical imaging lens group is 2.627mm, the aperture F / # is 1.65, the exit pupil distance is 5mm, and the full field of view is 20 degrees.

[0157] The relationship between the focal length of each lens and the total focal length of the lens in this embodiment is shown in Table 16:

[0158] Table 16 shows the relationship between the focal length of each lens and the total focal length of the lens in Example 6.

[0159]

[0160] Furthermore, in the embodiments of this specification, the preferred parameters for the radius of curvature, thickness, refractive index, and Abbe number of each lens in the optical imaging lens group are shown in Table 17:

[0161] Table 17 Structural parameters of the optical imaging lens assembly in Example 6

[0162]

[0163] It should be noted that Table 17 contains detailed structural data of the optical imaging lens assembly of Example 6. The units for radius of curvature, thickness and focal length are all millimeters, and the order of surfaces S1-8 indicates the surfaces from the first side to the second side; the optical surface with radius of curvature "Infinity" refers to a flat surface.

[0164] The conic and aspherical coefficients of the aspherical surfaces of each lens in the optical imaging lens assembly are shown in Table 18. Table 18: Conic and aspherical coefficients of the aspherical surfaces of each lens in the optical imaging lens assembly of Example 6.

[0165]

[0166] 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 28 As shown, the field distortion curve is as follows: Figure 29 As shown, the vertical axis color difference curve is as follows: Figure 30 As shown; among them, the optical transfer function (MTF) curve represents the overall resolution level of an optical system, the field curvature distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the transverse chromatic aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axis.

[0167] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element may be located on the first side of the optical imaging lens assembly, and the optical imaging lens assembly may be installed inside the housing.

[0168] Scanning display device

[0169] 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 3 As shown, the optical imaging lens group is positioned on the output optical path of the fiber optic scanner. The second 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 3 The corresponding content will not be elaborated on here.

[0170] In another possible implementation, this application also provides an application of the scanning display device as described above, that is, the scanning display device is configured in the projection field, specifically configured and applied in a near-eye display device, which can be configured on the temple of the near-eye display device.

[0171] The above description is merely a preferred embodiment of this application. Each embodiment is only used to illustrate the technical solution of this application and is not intended to limit this application. Any technical solution that can be obtained by those skilled in the art through logical analysis, reasoning or effective experimentation based on the concept of this application should be within the scope of this application.

[0172] 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.

[0173] The terms "first," "second," "first," or "second" as used in the various embodiments of this disclosure may modify various components regardless of their order and / or importance, but these terms do not limit the corresponding components. The above terms are configured only for the purpose of distinguishing one component from another.

Claims

1. An optical imaging lens assembly, characterized in that, The optical imaging lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged coaxially along a first side to a second side, with the first side being opposite to the light-emitting end of the fiber optic scanner; Wherein, the optical powers of the first lens to the third lens are positive, negative, and positive, respectively, and the optical power of the fourth lens is either positive or negative. The image-side of the first lens is convex, the object-side of the second lens is concave, the third lens is a biconvex lens, and the fourth lens is a meniscus lens that bends toward the second side. The image-side of the fourth lens is convex, and the object-side is concave.

2. The optical imaging lens assembly according to claim 1, characterized in that, Both the first lens and the fourth lens are aspherical lenses.

3. The optical imaging lens assembly according to claim 1 or 2, characterized in that, At least one of the second lens and the third lens is an aspherical lens.

4. The optical imaging lens assembly according to claim 1, characterized in that, The ratio of the focal length of the first lens to the total focal length of the optical imaging lens group is in the range of 1.07 to 1.76; the ratio of the focal length of the second lens to the total focal length of the optical imaging lens group is in the range of -1.23 to -0.62; the ratio of the focal length of the third lens to the total focal length of the optical imaging lens group is in the range of 0.53 to 1.37; and the ratio of the focal length of the fourth lens to the total focal length of the optical imaging lens group is in the range of -11.99 to 2.

63.

5. The optical imaging lens assembly according to claim 1, characterized in that, The first lens has a refractive index in the range of 1.5 to 1.6 and an Abbe number in the range of 35.6 to 81.6; the second lens has a refractive index in the range of 1.64 to 1.85 and an Abbe number in the range of 21.2 to 31.3; the third lens has a refractive index in the range of 1.5 to 1.8 and an Abbe number in the range of 49.2 to 81.3; and the fourth lens has a refractive index in the range of 1.7 to 1.8 and an Abbe number in the range of 34.4 to 49.

3.

6. The optical imaging lens assembly according to claim 1, characterized in that, The exit pupil distance of the optical imaging lens group is greater than 5mm.

7. The optical imaging lens assembly according to claim 1, characterized in that, The optical imaging lens group meets the following conditions: focal length range of 2.66mm to 2.75mm, field of view of 20 degrees, and aperture coefficient range of 1.62 to 1.

67.

8. The optical imaging lens assembly according to claim 1, characterized in that, The height of the zero-axis ray relative to the optical axis at the image plane side of any one of the first lens, the second lens, the third lens, and the fourth lens is greater than the height of the zero-axis ray relative to the optical axis at the object plane side of the lens.

9. A scanning display device, characterized in that, The device includes a fiber optic scanner and an optical imaging lens assembly and a galvanometer as described in any one of claims 1 to 8. The scanning fiber of the fiber optic scanner vibrates in one direction under the drive of a driving signal and forms a linear scanning trajectory. After passing through the optical imaging lens assembly, an image is formed under the action of the galvanometer.

Images