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 six lenses which are sequentially arranged along a common optical axis from a first side to a second side, the second lens is a meniscus aspheric lens, the object side surfaces of the first lens and the second lens are convex surfaces, and the image side surfaces of the first lens and the second lens are concave surfaces; the fourth lens is a biconcave lens, the fourth lens and one of the third lens and the fifth lens adjacent to the fourth lens form a glued lens, and the focal power of the other lens is positive; the image side surface of the sixth lens is a convex surface, and the object side surface of the sixth lens is a concave surface; and the focal length value of the image side surface of the second lens and the ratio of the curved surface radius of the sixth lens to the working distance of the sixth lens are limited, and the optical imaging lens group adopts spherical and aspherical lenses, so that the number of the lenses is reduced, and the imaging quality is improved, and the application of the lens group in a long working distance is met.

Description

Technical Field

[0001] The present application relates to the field of scanning display technology, and in particular to an optical imaging lens assembly and a scanning display device. Background Art

[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, existing scanning display imaging systems typically use an eyepiece-type vehicle-mounted projection lens for imaging. Due to the structural characteristics of a spherical eyepiece-type vehicle-mounted projection lens, the spherical lens has a weak ability to correct spherical aberration and requires a large number of lenses. In addition, it is difficult to balance aberrations such as coma and astigmatism during the imaging process under a large field of view, making it difficult for an eyepiece-type vehicle-mounted projection lens to achieve both a large field of view and high-quality imaging characteristics. Utility Model Content

[0004] The purpose of this application is to provide an optical imaging lens assembly that combines a spherical lens and an aspherical lens to meet the requirements of a vehicle-mounted projection scenario, which can reduce the number of lenses while meeting the requirements of a large field of view, small distortion, high resolution and a long working distance.

[0005] Another object of the present application is to provide an application of a scanning display device, which is configured for use in the field of vehicle-mounted projection and has the characteristics of high imaging quality, miniaturization, and lightness.

[0006] The present application provides an optical imaging lens assembly, which includes at least a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, which are sequentially arranged along a first side to a second side on a common optical axis. The first side corresponds to an imaging side, and the second side corresponds to a curved surface image at a light source end. The curved surface image is formed by a fiber scanner.

[0007] In which, the second lens is a meniscus aspheric lens and is curved toward the imaging side, the object side surfaces of the first lens and the second lens are both convex, and the image side surfaces of the first lens and the second lens are both concave; the fourth lens is a biconcave lens, the fourth lens forms a cemented lens with one of the adjacent third lens and fifth lens, and the optical power of the other lens is positive, the image side surface of the sixth lens is convex, and the object side surface of the sixth lens is concave; the focal length value of the image side surface of the second lens is in the range of -1.49 to -1.30, and the ratio of the curved surface radius of the sixth lens to the working distance from the sixth lens to the curved surface image is in the range of 1.58 to 2.3.

[0008] Furthermore, in a preferred embodiment of the present application, the optical powers corresponding to the first lens to the sixth lens are positive, negative, positive, negative, positive, and positive, respectively.

[0009] Furthermore, in a preferred embodiment of the present application, the optical imaging lens assembly also includes a seventh lens, the optical focal length of the seventh lens is positive, and the seventh lens is located between the fifth lens and the sixth lens, the image side surface of the seventh lens is convex, and the image side surface of the seventh lens is concave.

[0010] Furthermore, in a preferred embodiment of the present application, the combined focal length of the seventh lens and the sixth lens is in the range of 4.19 to 4.6.

[0011] Furthermore, in a preferred embodiment of the present application, the focal length of the object-side surface of the sixth lens is in the range of -2.94 to -2.40.

[0012] Furthermore, in a preferred embodiment of the present application, the Abbe number of the positive lens in the cemented lens is greater than the Abbe number of the negative lens in the cemented lens.

[0013] Furthermore, in a preferred embodiment of the present application, the sum of the ratio of the optical power to the Abbe number of one of the cemented lenses and the ratio of the optical power to the Abbe number of the other of the cemented lenses is in the range of -0.021 to -0.011.

[0014] The present application also provides a scanning display device, which includes a fiber scanner and the aforementioned optical imaging lens group, wherein the fiber scanner is used to scan and emit light of an image to be displayed, and the optical imaging lens group is used to magnify, image, and project a scanning surface corresponding to the light emitted by the fiber scanner; wherein the fiber scanner includes an actuator and an optical fiber fixed to the actuator, and the portion of the optical fiber that extends beyond the actuator forms a fiber cantilever, and the fiber cantilever performs two-dimensional scanning under the drive of the actuator.

[0015] The technical solutions in the embodiments of the present application can achieve the following technical effects: an optical imaging lens assembly that combines spherical and aspherical surfaces is used to meet the requirements of a large field of view, minimal distortion, and high resolution while reducing the number of lens elements; the concave surface of the sixth lens element and the curved image are oriented in the same direction, and under the premise that there is a long working distance between the object-side surface of the sixth lens element and the curved image, by limiting the ratio of the curvature radius to the working distance, the lens closest to the curved image can be well adapted to the curved image, which is conducive to receiving light from a wide viewing angle, thereby more comprehensively and fully capturing information from the curved image. Furthermore, when the light passes through the sixth lens to the second lens, the second lens is a meniscus aspheric surface with its concave surface (image side) facing the imaging side. This allows the second lens to utilize the principle of a uniform lens to produce a large positive field curvature while minimizing the generation of additional spherical aberration / coma / astigmatism. Since the focal length of the entire lens is positive, the optical power contribution of the positive lens is necessarily greater than the optical power contribution of the negative lens. The second lens is a meniscus aspheric lens with a small concave focal length and a large optical power, which can provide a large positive field curvature to deflect the light path upward, thereby offsetting the negative field curvature generated by the positive optical power lens, thereby improving the imaging quality of the optical imaging lens assembly.

[0016] Other features and advantages of the present application will be described in the following description and, in part, will become apparent from the description or be understood through implementation of the technical solutions of the present application. The objectives and other advantages of the present application can be achieved and obtained through the structures and / or processes specifically pointed out in the description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0018] Figure 1a 、 1b is a schematic structural diagram of an illustrative scanning display system;

[0019] Figure 2 is a schematic diagram of the scanning output of the optical fiber scanner provided in an embodiment of the present application;

[0020] Figure 3 This is a schematic structural diagram of an optical imaging lens assembly provided in Example 1 of the present application;

[0021] Figure 4 is an MTF curve diagram of the optical imaging lens assembly in Example 1 of the present application;

[0022] Figure 5 is a field curvature distortion curve diagram of the optical imaging lens assembly in Example 1 of the present application;

[0023] Figure 6is a diagram of vertical axis chromatic aberration of the optical imaging lens assembly in Example 1 of the present application;

[0024] Figure 7 This is a schematic structural diagram of an optical imaging lens assembly provided in Example 2 of the present application;

[0025] Figure 8 is an MTF curve diagram of the optical imaging lens assembly in Example 2 of the present application;

[0026] Figure 9 is a field curvature distortion curve diagram of the optical imaging lens assembly in Example 2 of the present application;

[0027] Figure 10 is a diagram of vertical axis chromatic aberration of the optical imaging lens assembly in Example 2 of the present application;

[0028] Figure 11 This is a schematic structural diagram of an optical imaging lens assembly provided in Example 3 of the present application;

[0029] Figure 12 is an MTF curve diagram of the optical imaging lens assembly in Example 3 of the present application;

[0030] Figure 13 is a field curvature distortion curve diagram of the optical imaging lens assembly in Example 3 of the present application;

[0031] Figure 14 This is a diagram of vertical axis chromatic aberration of the optical imaging lens assembly in Example 3 of the present application.

[0032] Icons: 100-processor; 110-laser group; 120-fiber scanning module; 130-transmission fiber; 140-light source modulation circuit; 150-scanning drive circuit; 160-beam combining unit; 121-scanning actuator; 121a-slow axis; 121b-fast axis; 122-fiber cantilever; 123-mirror group; 124-scanner package; 125-fixing part; 230-scanning surface; 240-imaging plane. DETAILED DESCRIPTION

[0033] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for explaining the relevant inventions and are not intended to limit the inventions. It should also be noted that, for ease of description, only the portions relevant to the relevant inventions are shown in the accompanying drawings.

[0034] Illustrative Scanning Display System

[0035] Current scanning display imaging can be achieved using a digital micromirror device (DMD) or a fiber scanning display (FSD). The FSD solution, a novel scanning display imaging method, uses a fiber scanner to scan and output images. To help those skilled in the art clearly understand the present invention, the following briefly describes the principles and corresponding systems of fiber scanning imaging.

[0036] like Figure 1a FIG. 1 is an illustrative scanning display system in the present application, which mainly includes:

[0037] The processor 100 , the laser group 110 , the optical fiber scanning module 120 , the transmission optical fiber 130 , the light source modulation circuit 140 , the scanning driving circuit 150 and the beam combining unit 160 .

[0038] The processor 100 may be a graphics processing unit (GPU), a central processing unit (CPU), or other chips or circuits with control functions and image processing functions, which are not specifically limited here.

[0039] During system operation, the processor 100 controls the light source modulation circuit 140 to modulate the laser array 110 based on the image data to be displayed. Laser array 110 includes multiple monochromatic lasers, each emitting a different color beam. As shown in Figure 1 , the laser array can specifically employ three lasers: red (R), green (G), and blue (B). The beams emitted by the lasers in laser array 110 are combined into a single laser beam by a beam combining unit 160 and coupled into the transmission fiber 130.

[0040] The processor 100 may also control the scanning driving circuit 150 to drive the optical fiber scanner in the optical fiber scanning module 120 to scan, thereby scanning and outputting the light beam transmitted in the transmission optical fiber 130 .

[0041] The light beam output by the optical fiber scanner acts on a certain pixel position on the surface of the medium and forms a light spot at the pixel position, thereby realizing the scanning of the pixel position. Driven by the optical fiber scanner, the output end of the transmission optical fiber 130 sweeps along a certain scanning trajectory, so that the light beam moves to the corresponding pixel position. During the actual scanning process, the light beam output by the transmission optical fiber 130 will form a light spot with corresponding image information (such as color, grayscale or brightness) at each pixel position. In one frame of time, the light beam traverses each pixel position at a sufficiently high speed to complete the scanning of one frame of image. Due to the "visual residual" characteristic of the human eye when observing things, the human eye cannot perceive the movement of the light beam at each pixel position, but sees a complete frame of image.

[0042] Continue to refer Figure 1b , is the specific structure of the fiber scanning module 120, which includes: a scanning actuator 121, a fiber cantilever 122, a mirror assembly 123, a scanner package 124, and a fixing member 125. The scanning actuator 121 is fixed to the scanner package 124 by the fixing member 125. The transmission fiber 130 extends from the front end of the scanning actuator 121 to form the fiber cantilever 122 (also called a scanning fiber). When working, the scanning actuator 121 is driven by the scanning drive signal, and its slow axis 121a (also called the first actuator) is moved along the vertical direction (the vertical direction is parallel to Figure 1a 、 1b The Y-axis in the reference coordinate system (in this application, the vertical direction may also be referred to as the first direction) vibrates, and its fast axis 121b (also referred to as the second actuating portion) vibrates along the horizontal direction (the horizontal direction is parallel to Figure 1a 、 1b The optical fiber cantilever 122 vibrates along the X-axis of the central reference coordinate system (in this application, this horizontal direction may also be referred to as the second direction). Driven by the scanning actuator 121, the front end of the optical fiber cantilever 122 performs a two-dimensional sweep along a predetermined trajectory and emits a light beam. The emitted light beam then passes through the lens assembly 123 to achieve scanning imaging. Generally, the structure formed by the scanning actuator 121 and the optical fiber cantilever 122 is referred to as a fiber scanner.

[0043] like Figure 2 As shown, in the embodiment of the present application, the motion trajectory of the light-emitting 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 lens group 123 (when the image is formed on a planar carrier, the image is a plane. It should be noted that in other embodiments, 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).

[0044] In order to facilitate description and enable those skilled in the art to easily understand the solution of the present application, it should be noted that the optical imaging lens assembly (such as Figure 2 The lens group 123 shown in FIG is used as an eyepiece. Through the action of the optical imaging lens group, the scanning surface 230 can be converted into an imaging plane 240 (in actual application, the transmission direction of the light is: from the scanning surface 230 to the imaging plane 240).

[0045] It should be further explained that in the projection field, the image corresponding to the imaging end is a plane image, and the corresponding plane image carrier can be a projection screen, curtain, ground, glass surface or wall surface, etc. The image corresponding to the light source end is a curved surface image, that is, an arc-shaped scanning surface scanned by a fiber optic scanner or emitted by other image sources; in the use scenario of the camera field, the optical path is opposite to that in the projection field. The light source end generally corresponds to the object side for collecting image information, and the imaging end generally corresponds to the image side obtained by collecting imaging.

[0046] Optical imaging lens

[0047] Please refer to Figure 3 、 Figure 7 as well as Figure 11The optical imaging lens assembly in the embodiment of the present application includes at least a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, which are arranged in sequence along a first side to a second side along a common optical axis. The first side corresponds to the imaging side, and the second side corresponds to the curved image at the light source end. The curved image is formed by a fiber scanner. The second lens is a meniscus-shaped aspheric lens curved toward the imaging side. The object side surfaces of the first and second lenses are both convex, and the image side surfaces of the first and second lenses are both concave. The fourth lens is a biconcave lens, forming a cemented lens with one of the adjacent third and fifth lenses. The other lens of the third and fifth lenses that does not form a cemented lens with the fourth lens has positive optical power. The image side surface of the sixth lens is convex, and the object side surface of the sixth lens is concave. The focal length of the image side surface of the second lens is in the range of -1.49 to -1.29, and the ratio of the curvature radius of the sixth lens to the working distance from the sixth lens to the curved image is in the range of 1.58 to 2.3. This embodiment of the present application utilizes both spherical and aspherical lenses in an optical imaging lens assembly, reducing the number of lens elements while meeting the requirements of a wide field of view, minimal distortion, and high resolution. Specifically, the concave surface of the sixth lens element and the curved image are oriented in the same direction. When the optical imaging lens assembly is used at a long working distance, by limiting the ratio of the sixth lens element's curved surface radius to the working distance from the sixth lens element to the curved image, the lens closest to the curved image can be optimally adapted to the curved image, facilitating the reception of light across a wide viewing angle, thereby enabling more comprehensive and adequate capture of information from the curved image. Furthermore, when the light passes through the sixth lens to the second lens, the second lens is a meniscus aspheric surface with its concave surface (image side) facing the imaging side. This allows the second lens to utilize the principle of a uniform lens to produce a large positive field curvature while minimizing the generation of additional spherical aberration / coma / astigmatism. Since the focal length of the entire lens is positive, the optical power contribution of the positive lens is necessarily greater than the optical power contribution of the negative lens. The second lens is a meniscus aspheric lens with a small concave focal length and a large optical power, which can provide a large positive field curvature to deflect the light path upward, thereby offsetting the negative field curvature generated by the positive optical power lens, thereby improving the imaging quality of the optical imaging lens assembly.

[0048] Furthermore, the optical focal lengths corresponding to the first lens to the sixth lens are positive, negative, positive, negative, positive, and positive, respectively. In the embodiment of the present application, by reasonably optimizing the positive and negative focal lengths of the six coaxial lenses of the optical imaging lens group, the optical focal length of the system can be reasonably dispersed, the aberrations generated by the lenses can be slowed down, the purpose of correcting multiple aberrations can be achieved, and clear imaging of the image side curved surface can be achieved. The negative focal length of the second lens can produce a larger positive field curvature. Relative to the positive focal length value of the entire lens, the optical focal length contribution of the positive lens must be greater than the optical focal length contribution of the negative lens. By limiting the ratio of the focal length of the second lens to the total focal length of the optical imaging lens group, the negative field curvature generated by these positive optical focal length lenses can be offset to improve the imaging quality. It should be noted that in the present application, the optical axis direction extending from the second side to the first side is the positive direction, and the optical axis direction extending from the first side to the second side is the negative direction.

[0049] Furthermore, the optical imaging lens assembly also includes a seventh lens, which has positive optical power and is located between the fifth lens and the sixth lens. The image side surface of the seventh lens is convex, and the image side surface of the seventh lens is concave. Furthermore, the combined focal length of the sixth lens and the seventh lens is in the range of 4.19 to 4.6. The first to fifth lenses can achieve a large positive field curvature, but this positive field curvature cannot match the curved surface image. Here, the additional seventh lens is provided on the basis of the sixth lens to better match the curved surface image, which is conducive to receiving light from a large viewing angle, so that the information from the curved surface image can be more fully and comprehensively captured.

[0050] Furthermore, the Abbe number of the positive lens in the cemented lens is greater than the Abbe number of the negative lens in the cemented lens. The use of cemented lenses here primarily balances the coma and astigmatism of the optical imaging lens system. Furthermore, after the light emitted by the curved image is diverged and converged by multiple lenses, the cemented lens formed by the fourth and fifth lenses diverges the converged light, ensuring that the light converges in the same plane. This also eliminates spherical and chromatic aberrations during the imaging process, ensuring image quality.

[0051] Furthermore, the sum of the ratio of the optical power to Abbe number of the fourth lens and the ratio of the optical power to Abbe number of the other lens in the cemented lens is within a range of -0.021 to -0.011. The sum of the ratios of the optical power to Abbe number of the two lenses in the cemented lens is close to 0, indicating good achromatic performance.

[0052] Furthermore, in a preferred embodiment of the present application, an aperture is provided on the first side of the optical imaging lens assembly. It should be noted that the aperture is designed to match the light emission angle of the image source. If the angle of the main ray of the image source is determined and converges in reverse near a point, the aperture can also be a virtual aperture.

[0053] Furthermore, in a possible implementation, the multiple lenses may be connected by spaced connections or by bonding them together, and the specific connection will depend on the needs of the actual application and is not limited here.

[0054] Further optionally, in one possible embodiment, the multiple lenses are all made of 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 between one-twentieth and one-tenth of that of glass, making them very conducive to low-cost mass production. Furthermore, plastic lenses can typically be injection molded, which is easy to process and can be easily processed into various surface structures that meet aspheric requirements. Plastic also reduces the overall weight of the lens, facilitating lightweight product design. Glass, on the other hand, has a higher and wider range of refractive indices, offering advantages in correcting lens aberrations. Its much lower coefficient of expansion facilitates precision assembly. Furthermore, due to its inherent resistance to high temperatures, UV rays, and acids and alkalis, glass offers significant advantages in terms of longevity and performance stability. It should be emphasized that other embodiments of this application are not limited to the two materials provided herein, namely plastic and glass; other materials capable of producing lenses may also be used.

[0055] Example 1

[0056] Figure 3This is a schematic diagram of the structure of an optical imaging lens assembly provided in Example 1. The optical imaging lens assembly includes six lenses arranged sequentially along the optical axis, namely, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6, arranged coaxially from the first side to the second side. The focal lengths of the first lens L1 to the sixth lens L6 are positive, negative, positive, negative, positive, and positive, respectively. Furthermore, an aperture stop is provided on the first side of the optical imaging lens assembly. The object-side surface S2 of the first lens L1, the object-side surface S4 of the second lens L2, and the object-side surface S6 of the third lens L3 are all convex surfaces. The image-side surface S1 of the first lens L1 is concave, the image-side surface S3 of the second lens L2 is concave, and the image-side surface S5 of the third lens L3 is concave. The second lens L2 is a meniscus-shaped aspheric lens that curves toward the aperture stop. The fourth lens L4 and the fifth lens L5 are cemented lenses. The fourth lens L4 is biconcave, and the fifth lens L5 is biconvex. The object-side surface of the fourth lens L4 and the image-side surface of the fifth lens L5 share a common surface S8. The sixth lens L6 is meniscus-shaped and curved toward the curved image. The image-side surface S10 of the sixth lens L6 is convex, and the object-side surface S11 of the sixth lens L6 is concave. It should be noted that the surface shapes of the above-mentioned lenses are only preferred and can be adjusted. For example, the image-side surface of the first lens L1 can be flat or convex, and the object-side surface of the fifth lens can be flat.

[0057] Furthermore, the second side of the optical imaging lens assembly of this embodiment corresponds to the curved surface image at the light source end. The lens F / # of the optical imaging lens assembly is 1.73mm, the total focal length is 1.56mm, the working distance is 1.5mm, and the full field of view angle is 36 degrees.

[0058] 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:

[0059] Table 1 Parameters of the relationship between the focal length of each lens and the total focal length of the lens in this embodiment

[0060]

[0061]

[0062] Furthermore, in the embodiment of the present application, the preferred parameters of the curvature radius, thickness parameter, refractive index and Abbe number of each lens of the optical imaging lens assembly for imaging a curved surface image are shown in Table 2:

[0063] Table 2 Structural parameters of the optical imaging lens assembly in Example 1

[0064]

[0065] It should be noted that Table 2 provides detailed structural data for the optical imaging lens assembly of Example 1. The units for the radius of curvature, thickness, and focal length are all in millimeters. Surfaces S1-S11 represent the surfaces from the first side to the second side. Optical surfaces with a curvature radius of "infinity" are flat. Furthermore, the single-surface focal length of the object-side surface S11 of the sixth lens L6 is -2.40 mm. Furthermore, the sum of the ratios of the optical power to Abbe number of the fourth lens and the fifth lens is -0.015.

[0066] In the embodiment of this specification, the second lens L2 is an aspherical lens. Specific parameters of the aspherical lens are shown in Table 3:

[0067] Table 3 Aspheric coefficients of the optical imaging lens assembly in Example 1

[0068]

[0069]

[0070] It should be noted that Table 3 shows detailed data of the image-side surface S3 and the object-side surface S4 of the second lens element L2 in the optical imaging lens assembly of Example 1.

[0071] Furthermore, after testing, when the above optical imaging lens assembly is used to project the image light corresponding to the scanning surface, the optical transfer function curve is as follows: Figure 4 As shown, the field curvature distortion curve is as follows Figure 5 As shown, the vertical axis chromatic aberration curve is as follows Figure 6 As shown in the figure; among them, the optical transfer function curve (Modulation Transfer Function, MTF) represents the comprehensive resolution level of an optical system, the field curvature distortion curve represents the F-Tan (theta) distortion value (percentage) under different field angles, and the vertical axis chromatic aberration curve represents the chromatic aberration size perpendicular to the axial direction.

[0072] Depend on Figure 4-Figure 6 It can be seen from the observation that the optical imaging lens assembly of Example 1 has good imaging resolution in the full field of view, and small optical system distortion and chromatic aberration. Therefore, the optical imaging lens assembly can clearly image the curved surface image scanned by the fiber scanner and has good imaging effects.

[0073] Of course, in actual applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element may be disposed on a first side of the optical imaging lens assembly, and the optical imaging lens assembly may be installed in the housing, so that the curved surface image formed by scanning an image source (such as a fiber scanner) can be imaged on a plane to achieve clear imaging.

[0074] Example 2

[0075] Figure 7 A schematic diagram of the structure of an optical imaging lens assembly provided in Example 2. The optical imaging lens assembly comprises seven lenses arranged sequentially along the optical axis, namely, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a seventh lens L7, and a sixth lens L6, arranged coaxially from the first side to the second side. The focal lengths of the first lens L1 to the sixth lens L6 are positive, negative, positive, negative, positive, positive, and positive, respectively. Furthermore, an aperture stop is provided on the first side of the optical imaging lens assembly. The object-side surface S2 of the first lens L1, the object-side surface S4 of the second lens L2, and the object-side surface S6 of the second lens L2 are all convex. The image-side surface S1 of the first lens L1 is concave, and the image-side surface S3 of the second lens L2 is concave. The second lens L2 is a meniscus aspheric lens that curves toward the aperture stop. The third lens L3 and the fourth lens L4 are cemented lenses. The object-side surface of the third lens L3 and the image-side surface of the fourth lens L4 share a common surface S6. The third lens L3 is a biconvex lens, and the fourth lens L4 is a biconcave lens. The image-side surface S8 of the fifth lens L5, the image-side surface S12 of the sixth lens L6, and the image-side surface S10 of the seventh lens L7 are all convex surfaces, the object-side surface S9 of the fifth lens L5 is a convex surface, the object-side surface S13 of the sixth lens L6 is a concave surface, and the object-side surface S11 of the seventh lens L7 is a concave surface. Among them, the sixth lens L6 is meniscus-shaped and is curved toward the curved image.

[0076] Furthermore, the second side of the optical imaging lens assembly of this embodiment corresponds to the curved image at the light source end. The lens F / # of the optical imaging lens assembly is 1.73mm, the total focal length is 1.56mm, the working distance is 1mm, and the full field of view is 36 degrees. It should be noted that the working distance in this embodiment refers to the distance on the optical axis between the concave surface of the second side of the optical imaging lens assembly (i.e., the object side surface of the sixth lens element) and the curved image.

[0077] 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:

[0078] Table 4 Parameters of the relationship between the focal length of each lens and the total focal length of the lens in this embodiment

[0079]

[0080] Furthermore, in the embodiments of this specification, the preferred parameters of the curvature radius, thickness parameter, refractive index and Abbe number of each lens of the optical imaging lens assembly for imaging a curved image are shown in Table 5:

[0081] Table 5 Structural parameters of the optical imaging lens assembly in Example 2

[0082]

[0083]

[0084] It should be noted that Table 5 provides detailed structural data for the optical imaging lens assembly of Example 2. The units for the radius of curvature, thickness, and focal length are all in millimeters. Surfaces S1-13 represent the surfaces from the first side to the second side in order; an optical surface with a curvature radius of "infinity" is considered flat. Furthermore, the single-sided focal length of the image-side surface S3 of the second lens element L2 is -1.33mm, the single-sided focal length of the object-side surface S7 of the fourth lens element L4 is -4.24mm, and the single-sided focal length of the object-side surface S13 of the sixth lens element L6 is -2.95mm. Furthermore, the sum of the ratio of the optical power to Abbe number of the fourth lens element and the ratio of the optical power to Abbe number of the fifth lens element is -0.021.

[0085] In the embodiment of this specification, the second lens L2 is an aspherical lens. Specific parameters of the aspherical lens are shown in Table 6:

[0086] Table 6 Aspheric coefficients of the optical imaging lens assembly in Example 2

[0087] Surface serial number K A4 A6 A8 A10 S3 -0.691 -0.029 0.056 -0.479 0.109 S4 -2.490 -0.034 0.003 -0.0007 7.521

[0088] It should be noted that Table 6 shows detailed data of the image-side surface S3 and the object-side surface S4 of the second lens element L2 in the optical imaging lens assembly of Example 2.

[0089] Furthermore, after testing, when the above optical imaging lens assembly is used to project the image light corresponding to the scanning surface, the optical transfer function curve is as follows: Figure 8 As shown, the field curvature distortion curve is as follows Figure 8 As shown, the vertical axis chromatic aberration curve is as follows Figure 10 As shown in the figure; among them, the optical transfer function curve (Modulation Transfer Function, MTF) represents the comprehensive resolution level of an optical system, the field curvature distortion curve represents the F-Tan (theta) distortion value (percentage) under different field angles, and the vertical axis chromatic aberration curve represents the chromatic aberration size perpendicular to the axial direction.

[0090] Depend on Figures 8-10 It can be seen from the observation that the optical imaging lens assembly of Example 2 has good imaging resolution in the full field of view, and small optical system distortion and chromatic aberration. Therefore, the optical imaging lens assembly can clearly image the scanned curved surface image of the fiber scanner and has good imaging effect.

[0091] Of course, in actual applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element may be disposed on a first side of the optical imaging lens assembly, and the optical imaging lens assembly may be installed in the housing, so that the curved surface image formed by scanning an image source (such as a fiber scanner) can be imaged on a plane to achieve clear imaging.

[0092] Example 3

[0093] Figure 11 A schematic diagram of the structure of an optical imaging lens assembly provided in Example 3. The optical imaging lens assembly comprises seven lenses arranged sequentially along the optical axis, namely, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a seventh lens L7, and a sixth lens L6, arranged coaxially from the first side to the second side. The focal lengths of the first lens L1 to the seventh lens L7 are positive, negative, positive, negative, positive, positive, and positive, respectively. Furthermore, an aperture stop is provided on the first side of the optical imaging lens assembly. The object-side surface S2 of the first lens L1, the object-side surface S4 of the second lens L2, and the object-side surface S6 of the second lens L2 are all convex. The image-side surface S1 of the first lens L1 is concave, and the image-side surface S3 of the second lens L2 is concave. The second lens L2 is a meniscus aspheric lens that curves toward the aperture stop. The third lens L3 and the fourth lens L4 are cemented lenses. The object-side surface of the third lens L3 and the image-side surface of the fourth lens L4 share a common surface S6. The third lens L3 is a biconvex lens, and the fourth lens L4 is a biconcave lens. The image-side surface S8 of the fifth lens L5, the image-side surface S12 of the sixth lens L6, and the image-side surface S10 of the seventh lens L7 are all convex surfaces, the object-side surface S9 of the fifth lens L5 is a convex surface, the object-side surface S13 of the sixth lens L6 is a concave surface, and the object-side surface S11 of the seventh lens L7 is a concave surface. Among them, the sixth lens L6 is meniscus-shaped and is curved toward the curved image.

[0094] Furthermore, the second side of the optical imaging lens assembly of this embodiment corresponds to the curved surface image at the light source end. The lens F / # of the optical imaging lens assembly is 1.72mm, the total focal length is 1.56mm, the working distance is 1mm, and the full field of view angle is 36 degrees.

[0095] 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:

[0096] Table 7 Parameters of the relationship between the focal length of each lens and the total focal length of the lens in this embodiment

[0097]

[0098]

[0099] Furthermore, in the embodiment of the present application, the preferred parameters of the curvature radius, thickness parameter, refractive index and Abbe number of each lens of the optical imaging lens assembly for imaging a curved surface image are shown in Table 8:

[0100] Table 8 shows the structural parameters of the optical imaging lens assembly in Example 3

[0101]

[0102] It should be noted that Table 8 provides detailed structural data for the optical imaging lens assembly of Example 3. The units for the radius of curvature, thickness, and focal length are all in millimeters. Surfaces S1-S13 represent surfaces from the first side to the second side. Optical surfaces with a curvature radius of "infinity" are flat. Furthermore, the single-sided focal length of the image-side surface S3 of the second lens L2 is -1.30 mm, the single-sided focal length of the object-side surface S7 of the fourth lens L4 is -8.88 mm, and the single-sided focal length of the object-side surface S13 of the sixth lens L6 is -5.40 mm. The sum of the ratio of the optical power to Abbe number of the fourth lens and the ratio of the optical power to Abbe number of the fifth lens is -0.011.

[0103] In the embodiment of this specification, the second lens L2 is an aspherical lens. Specific parameters of the aspherical lens are shown in Table 3:

[0104] Table 9 Aspheric coefficients of the optical imaging lens assembly in Example 3

[0105] Surface serial number K A4 A6 A8 A10 S3 -0.687 -0.021 0.104 -0.335 0.469 S4 -2.374 0.040 0.005 -0.001 0.0001

[0106] It should be noted that Table 9 shows detailed data of the image-side surface S3 and the object-side surface S4 of the second lens element L2 in the optical imaging lens assembly of Example 3.

[0107] Furthermore, after testing, when the above optical imaging lens assembly is used to project the image light corresponding to the scanning surface, the optical transfer function curve is as follows: Figure 12 As shown, the field curvature distortion curve is as follows Figure 13 As shown, the vertical axis chromatic aberration curve is as follows Figure 14 As shown in the figure; among them, the optical transfer function curve (Modulation Transfer Function, MTF) represents the comprehensive resolution level of an optical system, the field curvature distortion curve represents the F-Tan (theta) distortion value (percentage) under different field angles, and the vertical axis chromatic aberration curve represents the chromatic aberration size perpendicular to the axial direction.

[0108] Depend on Figure 12-14 It can be seen from the observation that the optical imaging lens assembly of Example 3 has good imaging resolution in the full field of view, and small optical system distortion and chromatic aberration. Therefore, the optical imaging lens assembly can clearly image the scanned curved surface image of the fiber scanner and has good imaging effect.

[0109] Of course, in actual applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element may be disposed on a first side of the optical imaging lens assembly, and the optical imaging lens assembly may be installed in the housing, so that the curved surface image formed by scanning an image source (such as a fiber scanner) can be imaged on a plane to achieve clear imaging.

[0110] Scanning display device

[0111] The aforementioned optical imaging lens assembly can be used in conjunction with a fiber scanner (or a corresponding fiber scanning module) to form a scanning display device (such as Figure 1a 、 1b As shown, the optical imaging lens group is arranged on the light output path of the fiber scanner), wherein the second side of the optical imaging lens group faces the light output direction of the fiber scanner. Preferably, the optical imaging lens group is coaxial with the central optical axis of the fiber scanner. Of course, the structure and general principle of the fiber scanner can be referred to the aforementioned Figure 1a 、 1b I will not go into details about the corresponding content here.

[0112] In addition, in a possible embodiment, the present application also provides an application of the above-mentioned scanning display device, that is, the above-mentioned scanning display device is configured in the projection field, specifically configured and applied in vehicle-mounted projection. It can not only be configured in relevant positions in the vehicle such as the external body or head-up display, but it can also be configured in the vehicle for projection display, and can be flexibly set according to the display requirements of the vehicle-mounted projection.

[0113] In some embodiments, the scanning display device can be applied to vehicles, including but not limited to cars, motorcycles, electric bicycles, balance cars, scooters, etc. In some embodiments, the vehicle-mounted projection system can also be used in other vehicles with transportation capabilities, such as aircraft, ships, wheelchairs, etc. Taking a car as a specific example, the optical imaging module of the scanning display device can be set at the door, front or rear of the car to project the image onto the ground around the car body. It should be noted that the image corresponding to the imaging end is a plane image, and the corresponding plane image carrier can be, for example, a projection screen, a curtain, the ground or a glass surface. It should be noted that in the specific application of the scanning display device, the number of scanning display devices can be one or more groups. When the scanning display device is located at different positions of the carrier (for example, a vehicle), the specifications of the fiber optic scanner, the distribution of each lens in the optical imaging lens group, the parameters, etc. can be adaptively adjusted according to the specific scenario.

[0114] The above description is merely a preferred specific embodiment of the present application. Each embodiment is only used to illustrate the technical solution of the present application and is not intended to limit the present application. Any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or effective experiments based on the concept of the present application should be within the scope of the present application.

[0115] The various embodiments in this application are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0116] The expressions "first," "second," "the first," or "the 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 corresponding components. The above expressions are only configured for the purpose of distinguishing an element from other elements.

Claims

1. An optical imaging lens assembly, characterized in that: The optical imaging lens assembly comprises at least a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, which are sequentially arranged along a first side to a second side on a common optical axis, wherein the first side corresponds to an imaging side, and the second side corresponds to a curved surface image at the light source end, wherein the curved surface image is formed by a fiber scanner; The second lens is a meniscus aspheric lens and is curved toward the imaging side. The object side surfaces of the first and second lenses are both convex, and the image side surfaces of the first and second lenses are both concave. The fourth lens is a biconcave lens, and the fourth lens forms a cemented lens with one of the adjacent third and fifth lenses, and the optical power of the other lens is positive. The image side surface of the sixth lens is convex, and the object side surface of the sixth lens is concave. The focal length of the image side surface of the second lens is in the range of -1.49 to -1.29, and the ratio of the curved surface radius of the sixth lens to the working distance from the sixth lens to the curved surface image is in the range of 1.58 to 2.

3.

2. The optical imaging lens assembly according to claim 1, wherein: The optical powers corresponding to the first lens to the sixth lens are positive, negative, positive, negative, positive, and positive, respectively.

3. The optical imaging lens assembly according to claim 2, wherein: The optical imaging lens assembly also includes a seventh lens, which has positive optical power and is located between the fifth lens and the sixth lens. The image side surface of the seventh lens is convex and the image side surface of the seventh lens is concave.

4. The optical imaging lens assembly according to claim 3, wherein: The combined focal length of the seventh lens and the sixth lens is in the range of 4.19 to 4.

6.

5. The optical imaging lens assembly according to claim 1, wherein: The focal length of the object side surface of the sixth lens is in the range of -2.94 to -2.

40.

6. The optical imaging lens assembly according to claim 1 or 3, characterized in that: The Abbe number of the positive lens in the cemented lens is greater than the Abbe number of the negative lens in the cemented lens.

7. The optical imaging lens assembly according to claim 6, wherein: The sum of the ratio of the optical power to the Abbe number of one of the cemented lenses and the ratio of the optical power to the Abbe number of the other of the cemented lenses is within the range of -0.021 to -0.

011.

8. The optical imaging lens assembly according to claim 1, wherein: The first side is provided with an aperture.

9. A scanning display device, characterized in that: A device comprising a fiber scanner and an optical imaging lens assembly according to any one of claims 1 to 8, wherein the fiber scanner is used to scan and emit light for an image to be displayed, and the optical imaging lens assembly is used to magnify and project a scanning surface corresponding to the light emitted by the fiber scanner; The fiber scanner includes an actuator and an optical fiber fixed on the actuator. The portion of the optical fiber extending beyond the actuator forms an optical fiber cantilever. The optical fiber cantilever performs two-dimensional scanning under the drive of the actuator.

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