Optical imaging lens and scanning display device

Abstract

This application discloses an optical imaging lens assembly and a scanning display device, relating to the field of scanning display technology. The optical imaging lens assembly provided in this application comprises a front lens group and a rear lens group arranged coaxially along a first side to a second side. The first side is the imaging side, and the second side corresponds to a curved image at the light source end. The curved image is formed by a fiber optic scanner. The front lens group has a positive focal length, receives light from the first side, and converts it into an inverted and reduced intermediate image, located between the front and rear lens groups. The rear lens group has a positive focal length and converts the intermediate image into an inverted and magnified real image. The total focal length of the optical imaging lens assembly is negative, wherein the focal length ratio of the front lens group to the rear lens group is in the range of 1.3 to 2.61.

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] To ensure the compactness of the subsequent optical path, existing scanning display imaging systems typically use eyepiece-type vehicle projection lenses for imaging, resulting in a longer exit pupil distance. However, because eyepiece-type vehicle projection lenses offer relatively limited control over the light path, they struggle to balance aberrations such as coma and astigmatism during the imaging process in a large field of view. Consequently, eyepiece-type vehicle projection lenses find it difficult to simultaneously achieve both a large field of view and high-quality imaging characteristics. Summary of the Invention

[0004] The purpose of this application is to provide a negative focal optical imaging lens group that generates an intermediate image plane, which has a higher degree of freedom in controlling the direction of light and can achieve optical characteristics beyond the interpupillary distance to meet the needs of vehicle projection scenarios. It can meet the requirements of large field of view, small distortion and high resolution while ensuring the compactness of the projection system.

[0005] This application provides an optical imaging lens assembly, comprising a front lens group and a rear lens group arranged coaxially along a first side to a second side. The first side is the imaging side, and the second side corresponds to a curved image at the light source end. The curved image is formed by a fiber optic scanner. The front lens group has a positive focal length, receives light from the first side, and converts it into an inverted and reduced intermediate image, which is located between the front lens group and the rear lens group. The rear lens group has a positive focal length, and the image-side focal plane of the rear lens group is located on the object-side surface of the intermediate image, converting the intermediate image into an inverted real image. The total focal length of the optical imaging lens assembly is negative, wherein the focal length ratio of the front lens group to the rear lens group is in the range of 1.3 to 2.61.

[0006] Furthermore, in a preferred embodiment of this application, the focal length range of the front lens group is 2.17 to 2.72.

[0007] Furthermore, in a preferred embodiment of this application, the front lens group includes a first lens and a second lens arranged along the optical axis from the first side to the second side. The optical power of the first lens and the second lens are both positive. The image-side surface of the first lens is convex, the image-side surface of the second lens is convex, and the object-side surface of the second lens is concave.

[0008] Furthermore, in a preferred embodiment of this application, the focal length range of the rear lens group is 0.83 to 2.1.

[0009] Further, in a preferred embodiment of this application, the rear lens group includes a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged along the optical axis from the first side to the second side. The optical powers of the third lens to the ninth lens are negative, positive, positive, negative, positive, positive, and positive, respectively. The third lens is an aspherical lens, curved towards the curved image surface. The object side of the third lens is a concave aspherical surface, and the image side of the third lens is a curved aspherical surface. The absolute value of the ratio of the total focal length of the third lens to the total focal length of the optical imaging lens group is in the range of 0.97 to 3.09.

[0010] Further, in a preferred embodiment of this application, the rear lens group includes a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged along the optical axis from the first side to the second side, wherein the optical powers of the fourth lens to the ninth lens are positive, positive, negative, positive, positive, and positive, respectively; wherein the third lens includes two lenses, both of which are biconcave lenses.

[0011] Further, in a preferred embodiment of this application, the image-side surface of the fourth lens is a plane or a concave surface, and the object-side surface of the fourth lens is a convex surface; the image-side surface of the fifth lens is a convex surface, and the object-side surface of the fifth lens is a convex surface or a plane; the image-side surface of the sixth lens is a plane or a concave surface, and the object-side surface of the sixth lens is a concave surface; or, the fifth lens is a biconvex lens, the sixth lens is a biconcave lens, and the fifth lens and the sixth lens form a cemented lens; the object-side surface of the seventh lens is a convex surface; the image-side surfaces of the eighth lens and the ninth lens are convex surfaces, and the object-side surfaces of the eighth lens and the ninth lens are concave surfaces.

[0012] Furthermore, in a preferred embodiment of this application, the ratio of the focal length of the sixth lens to the total focal length of the optical imaging lens group is in the range of 0.68 to 1.46, and the optical power of the object side of the sixth lens is in the range of -2.026 to -1.28.

[0013] Furthermore, in a preferred embodiment of this application, the total optical power of the seventh lens, the eighth lens, and the ninth lens is in the range of 0.67 to 0.93.

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

[0015] This application also provides an application of the scanning display device as described above, comprising: configuring the scanning display device in the field of vehicle display.

[0016] The technical solutions in this application embodiment can achieve the following technical effects: The optical imaging lens assembly provided in this specification utilizes a negative focal optical imaging lens assembly that generates an intermediate image plane, providing greater freedom in controlling the direction of light. While achieving optical characteristics exceeding the interpupillary distance, it also meets the requirements of a large field of view, low distortion, and high resolution. Specifically, in terms of aberration correction, in a positive focal optical imaging lens assembly, since off-axis large field-of-view rays are all above the optical axis, the height of the second auxiliary ray on all lenses is positive. When the field of view increases, coma and astigmatism become difficult to correct. The negative focal optical imaging lens assembly provided in this application, by controlling the focal length ratio of the front and rear lens groups, allows the optical imaging lens assembly to form a secondary focusing structure with an intermediate image plane. This places off-axis large field-of-view rays on both sides of the optical axis, meaning the height of the second auxiliary ray on the lens can be both positive and negative. Thus, even when the field of view increases, coma and astigmatism can still be easily corrected.

[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 the structure of an optical imaging lens assembly provided in Embodiment 1 of this application;

[0022] Figure 4 This is the MTF curve of the optical imaging lens group in Embodiment 1 of this application;

[0023] Figure 5 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 1 of this application;

[0024] Figure 6 This is the transverse chromatic aberration diagram of the optical imaging lens group in Embodiment 1 of this application;

[0025] Figure 7 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 2 of this application;

[0026] Figure 8 This is the MTF curve of the optical imaging lens group in Embodiment 2 of this application;

[0027] Figure 9 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 2 of this application;

[0028] Figure 10 This is the transverse chromatic aberration diagram of the optical imaging lens group in Embodiment 2 of this application;

[0029] Figure 11 This is a schematic diagram of the structure of an optical imaging lens assembly provided in Embodiment 3 of this application;

[0030] Figure 12 This is the MTF curve of the optical imaging lens group in Embodiment 3 of this application;

[0031] Figure 13 This is a field curvature distortion curve of the optical imaging lens group in Embodiment 3 of this application;

[0032] Figure 14 This is the transverse chromatic aberration diagram of the optical imaging lens group in Embodiment 3 of this application;

[0033] Icons: 100-Processor; 110-Laser group; 120-Fiber optic scanning module; 130-Transmission fiber; 140-Light source modulation circuit; 150-Scanning drive circuit; 160-Band combining unit; 121-Scanning actuator; 121a-Slow axis; 121b-Fast axis; 122-Fiber optic cantilever; 123-Mirror group; 124-Scanner package; 125-Fixture; 230-Scanning surface; 240-Imaging plane. Detailed Implementation

[0034] 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.

[0035] Explanatory Scanning Display System

[0036] 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.

[0037] like Figure 1a The image shown is an illustrative scanning display system according to this application, which mainly includes:

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] Continue to refer to Figure 1b The specific structure of the fiber optic scanning module 120 includes: a scanning actuator 121, a fiber optic cantilever 122, a mirror assembly 123, a scanner housing 124, and a fixing member 125. The scanning actuator 121 is fixed to the scanner housing 124 by the fixing member 125. The transmission fiber 130 extends from the front end of the scanning actuator 121 to form the fiber optic cantilever 122 (also called the scanning fiber). During operation, driven by the scanning drive signal, the slow axis 121a (also called the first actuation part) of the scanning actuator 121 moves along the vertical direction (this vertical direction is parallel to the...). Figure 1a , 1b The Y-axis in the reference coordinate system (in this application, the vertical direction can also be referred to as the first direction) vibrates, and its fast axis 121b (also referred to as the second actuator) vibrates along the horizontal direction (this horizontal direction is parallel to the reference coordinate system). Figure 1a , 1b The X-axis in the reference coordinate system (in this application, this horizontal direction can also be referred to as the second direction) vibrates, driven by the scanning actuator 121. The front end of the fiber optic cantilever 122 performs a two-dimensional sweep along a preset trajectory and emits a light beam. The emitted light beam can then pass through the mirror assembly 123 to achieve scanning imaging. Generally, the structure composed of the scanning actuator 121 and the fiber optic cantilever 122 can be called a fiber optic scanner.

[0044] 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 mirror group 123, it is converted into an imaging plane 240 (when imaging is performed on a planar carrier, the image is a plane; it should be noted that in other embodiments of the present invention, the image formed after passing through the mirror 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). It should be noted that the first actuator in the optical fiber scanner provided in this embodiment may not operate, that is, the optical fiber scanner only moves in the fast axis direction.

[0045] To facilitate description and enable those skilled in the art to easily understand the solution of this application, it should be noted that the optical imaging lens assembly in this application (such as...) Figure 2 The lens group 123 shown serves as an eyepiece. Through the action of this optical imaging lens group, the scanning surface 230 can be converted into an imaging plane 240 (in actual applications, the direction of light transmission is from the scanning surface 230 to the imaging plane 240).

[0046] It should be further noted that in the field of projection, the image corresponding to the imaging end is a planar image, and the corresponding planar image carrier can be such as a projection screen, screen, ground, glass surface or wall, etc. The image corresponding to the light source end is a curved image, that is, the arc-shaped scanning surface scanned by the fiber optic scanner or emitted by other image sources. In the application scenario of the camera field, the optical path is reversed in the field of projection. The light source end generally corresponds to the object side that collects image information, and the imaging end generally corresponds to the image side that is collected and imaged.

[0047] Optical imaging lens group

[0048] Please refer to Figure 3 , Figure 7 and Figure 11 The optical imaging lens assembly in this embodiment includes a front lens group and a rear lens group arranged coaxially along a first side to a second side. The first side is 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 optic scanner. The front lens group has a positive focal length, receives light from the first side, and converts it into an inverted and reduced intermediate image, which is located between the front and rear lens groups. The rear lens group has a positive focal length and converts the intermediate image into an inverted real image. The total focal length of the optical imaging lens assembly is negative, wherein the focal length ratio of the front and rear lens groups is in the range of 1.3 to 2.61. Specifically, in terms of aberration correction, current positive focal optical imaging lens assemblies suffer from aberrations because off-axis large field-of-view rays are all above the optical axis, resulting in the second auxiliary ray having a positive height on all lenses. As the field of view increases, coma and astigmatism become difficult to correct. The negative focal length optical imaging lens group provided in this application controls the focal length ratio of the front and rear lenses, so that the optical imaging lens group forms a secondary focusing structure with the middle image plane, so that the off-axis large field of view light rays are located on the upper and lower sides of the optical axis, that is, the height of the second auxiliary light rays on the lens is both positive and negative. In this way, even if the field of view increases, it is easy to correct coma and astigmatism.

[0049] In the embodiments of this specification, an aperture is provided on the first side to match the light output angle of the image source. If the angle of the main light ray of the image source is determined and converges in the opposite direction near a point, the aperture can also be a virtual aperture.

[0050] Furthermore, the focal length range of the front lens group is 2.17 to 2.72. The front lens group includes a first lens and a second lens arranged coaxially along the first side to the second side. Both the first lens and the second lens have positive optical power. The image-side surface of the first lens is convex, the image-side surface of the second lens is convex, and the object-side surface of the second lens is concave. The front lens group can provide a large positive optical power. These two positive lenses will produce a large negative field curvature, and at the same time, light will be focused to form an intermediate image after passing through these two lenses. It should be noted that the number and surface structure of the front lens group are only a specific example provided in this application. In other alternative embodiments, the first lens and the second lens can also be separated into multiple lenses with separate and cemented positive and negative optical powers, or only a single lens can be used, as long as the optical power of the front lens group is positive and the focal length value is within the above range.

[0051] Furthermore, the focal length range of the rear lens group is 0.83 to 2.1. The focal length of this rear lens group is positive. By limiting the focal length range of the rear lens group, the ratio of the distance from the intermediate image formed by the front lens group to the principal surface of the rear lens group to the focal length of the rear lens group is greater than 1 (i.e., the object point is located beyond one focal length, forming an inverted and magnified real image). This makes the focal length of the entire lens system negative, while still forming an upright and magnified real image. It should be noted that the rear lens group in the three embodiments provided later in this specification is only a specific example. The number and surface structure of the lenses in the rear lens group can be adjusted accordingly, as long as the optical power of the rear lens group is positive and the focal length value is within the above-mentioned range.

[0052] Furthermore, in some embodiments, the rear lens group includes a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged along the optical axis from the first side to the second side. The optical powers of the third to ninth lenses are negative, positive, positive, negative, positive, positive, and positive, respectively. The third lens is an aspherical lens, curved towards the curved image surface. The object-side surface of the third lens is a concave aspherical surface, and the image-side surface is a curved aspherical surface. The absolute value of the ratio of the third lens to the total focal length of the optical imaging lens group is in the range of 0.97 to 3.09. It should be noted that this optical imaging lens group, using both spherical and aspherical lenses, satisfies the requirements of a large field of view, low distortion, and high resolution while reducing the number of lenses. Specifically, when light passes through the ninth lens to the third lens, the third lens is a meniscus aspherical with its concave surface (object side) facing the curved image. This allows the second lens to utilize the principle of a simulacrum lens to generate a large negative field curvature while minimizing additional spherical aberration / coma / astigmatism. Since the entire lens has a negative focal length, only the sixth lens among the fourth to ninth lenses has a negative focal length. The optical power contribution of the third lens is relatively large. The third lens uses a meniscus aspherical lens with a small focal length and a large optical power, which can provide a large positive field curvature to deflect the light path upward, thus offsetting the negative field curvature generated by the positive optical power lens and improving the imaging quality of the optical imaging lens group.

[0053] In another embodiment, the rear lens group may include a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged along the optical axis from the first side to the second side, wherein the optical powers of the fourth lens to the ninth lens are positive, positive, negative, positive, positive, and positive, respectively; wherein, the first sub-lens and the second sub-lens in the third lens are arranged adjacently and are both lenses with negative optical powers, and can function as aspherical lenses in the above embodiments.

[0054] Furthermore, the image-side surface of the fourth lens is either flat or concave, and the object-side surface of the fourth lens is convex; the image-side surface of the fifth lens is convex, and the object-side surface of the fifth lens is either convex or flat; the image-side surface of the sixth lens is either flat or concave, and the object-side surface of the sixth lens is concave; alternatively, the fifth lens is a biconvex lens, the sixth lens is a biconcave lens, and the fifth lens and the sixth lens form a cemented lens; the object-side surface of the seventh lens is convex; the image-side surfaces of the eighth and ninth lenses are convex, and the object-side surfaces of the eighth and ninth lenses are concave. Here, the object-side surfaces of the eighth and ninth lenses are concave, which can better match the curved image, is beneficial for receiving light from a large angle, and thus can more comprehensively and fully capture information from the curved image.

[0055] Furthermore, the ratio of the focal length to the total focal length of the sixth lens ranges from 0.68 to 1.46, and the optical power of the object-side surface of the sixth lens ranges from -2.026 to -1.28; the total optical power of the seventh, eighth, and ninth lenses ranges from 0.67 to 0.93. The object-side surface of the sixth lens is concave, i.e., it has a negative optical power surface, which can diverge light rays. While correcting field curvature, by limiting the optical power value of the object-side surface of the sixth lens and the optical power of the three positive optical power spherical lenses (the seventh to ninth lenses), a positive-negative combination effect can be produced, thereby eliminating spherical aberration.

[0056] 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.

[0057] 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 shapes. 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 two materials provided in the embodiments of the present invention: plastic and glass. Other materials suitable for making lenses can also be used.

[0058] Example 1

[0059] Figure 3This is a schematic diagram of an optical imaging lens assembly provided in Embodiment 1. The optical imaging lens assembly includes nine 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 sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9 arranged coaxially from the first side to the second side. The first lens L1 and the second lens L2 form the front lens group, and the third to ninth lenses L3 form the rear lens group. The focal lengths of the first lens L1 to the ninth lens L9 are positive, positive, negative, positive, positive, negative, positive, positive, and positive, respectively. Further, an aperture stop is located on the first side of the optical imaging lens assembly. The image-side surface S1 of the first lens L1 and the image-side surface S3 of the second lens L2 are both convex surfaces. The object-side surface S2 of the first lens L1 is convex, and the object-side surface S4 of the second lens L2 is concave. The third lens L3 is a meniscus aspherical lens, curved towards the curved image surface. Its image-side surface S5 is a convex aspherical surface, and its object-side surface S6 is a concave aspherical surface. The fourth lens L4 has an image-side surface S7 that is concave, and its object-side surface S8 that is convex. The fifth lens L5, the seventh lens L7, and the eighth lens L8 are all biconvex lenses, and the sixth lens L6 is a biconcave lens. The ninth lens L9 is meniscus, curved towards the curved image surface. Its image-side surface S17 is convex, and its object-side surface S18 is concave. It should be noted that the surface shapes of the lenses in the optical imaging lens group are not limited to the above descriptions and can be appropriately adjusted. For example, the image-side surface of the first lens L1, the fourth lens L4, and the sixth lens L6 can also be flat.

[0060] Furthermore, in this embodiment, the second side of the optical imaging lens group corresponds to the curved image at the light source end. The lens of the optical imaging lens group has an F / # of 1.86mm, a total focal length of -1.3mm, and a full field of view of 45 degrees.

[0061] 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:

[0062] Table 1 shows the relationship between the focal length of each lens element and the total focal length of the lens in this embodiment.

[0063]

[0064] 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 for imaging curved surface images are shown in Table 2:

[0065] Table 2 Structural parameters of the optical imaging lens assembly in Example 1

[0066]

[0067]

[0068] 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 S1-18 indicates the surfaces from the first side to the second side; the optical surface with radius of curvature "Infinity" refers to a plane.

[0069] In the embodiments described in this specification, the third lens L3 is an aspherical lens. Specific parameters for the aspherical lens are detailed in Table 3.

[0070] Table 3 Aspheric coefficients of the optical imaging lens group in Example 1

[0071] Surface serial number K A4 A6 A8 A10 S3 0.56 0.40 -0.56 0.32 -0.08 S4 -0.97 0.21 -2.95 6.59 -5.57

[0072] It should be noted that Table 3 contains detailed data on the image side S5 and object side S6 of the third lens L3 in the optical imaging lens group of Embodiment 1.

[0073] 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 4 As shown, the field distortion curve is as follows: Figure 5 As shown, the vertical axis color difference curve is as follows: Figure 6 As shown; among them, the Modulation Transfer Function (MTF) curve represents the overall resolution level of an optical system, the Field Curve Distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the Vertical Chromatic Aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0074] Depend on Figures 4-6 Observations show that the optical imaging lens group in Example 1 has good imaging resolution, small optical system distortion and chromatic aberration across the entire field of view. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber optic scanner and has good imaging effect.

[0075] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element can be set on the first side of the optical imaging lens assembly, and the optical imaging lens assembly can be installed in the housing, so that the curved image formed by the image source (such as a fiber optic scanner) can be imaged on a plane to achieve clear imaging.

[0076] Example 2

[0077] Figure 7This is a schematic diagram of an optical imaging lens assembly provided in Embodiment 2. The optical imaging lens assembly includes nine 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 sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9 arranged coaxially from the first side to the second side. The first lens L1 and the second lens L2 form the front lens group, and the third lens L3 to the ninth lens L9 form the rear lens group. The focal lengths of the first lens L1 to the ninth lens L9 are positive, positive, negative, positive, positive, negative, positive, positive, and positive, respectively. Further, an aperture stop is located on the first side of the optical imaging lens assembly. The image-side surface S1 of the first lens L1 and the image-side surface S3 of the second lens L2 are both convex surfaces. The object-side surface S2 of the first lens L1 is convex, and the object-side surface S4 of the second lens L2 is concave. The third lens L3 is a meniscus aspherical lens, curved towards the curved image surface. Its image-side surface S5 is a convex aspherical surface, and its object-side surface S6 is a concave aspherical surface. The fourth lens L4 has an image-side surface S7 that is concave, and its object-side surface S8 that is convex. The fifth lens L5 and the seventh lens L7 are both biconvex lenses, and the sixth lens L6 is a biconcave lens. The fifth lens L5 and the sixth lens L6 are combined to form a cemented lens. The eighth lens L8 has an image-side surface S14 that is convex, and its object-side surface S15 that is concave. The ninth lens L9 is meniscus, curved towards the curved image surface. Its image-side surface S16 is convex, and its object-side surface S17 that is concave. It should be noted that the surface shapes of the lenses in the optical imaging lens group are not limited to the above descriptions and can be appropriately adjusted. For example, the image-side surface of the first lens L1 can also be flat, and the image-side surface of the fourth lens L4 can also be flat.

[0078] Furthermore, in this embodiment, the second side of the optical imaging lens group corresponds to the curved image at the light source end. The lens of the optical imaging lens group has an F / # of 1.64mm, a total focal length of -1mm, and a full field of view of 45 degrees.

[0079] 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:

[0080] Table 4 shows the relationship between the focal length of each lens element and the total focal length of the lens in this embodiment.

[0081]

[0082]

[0083] 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 for imaging curved surface images are shown in Table 5:

[0084] Table 5 Structural parameters of the optical imaging lens assembly in Example 2

[0085]

[0086] 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 S1-17 indicates the surfaces from the first side to the second side; the optical surface with radius of curvature "Infinity" refers to a flat surface.

[0087] In the embodiments described in this specification, the third lens L3 is an aspherical lens. Specific parameters for the aspherical lens are detailed in Table 6.

[0088] Table 6. Aspheric coefficients of the optical imaging lens group in Example 2.

[0089]

[0090]

[0091] It should be noted that Table 6 contains detailed data on the image side S5 and object side S6 of the third lens L3 in the optical imaging lens group of Embodiment 2.

[0092] 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 10 As shown; among them, the Modulation Transfer Function (MTF) curve represents the overall resolution level of an optical system, the Field Curve Distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the Vertical Chromatic Aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0093] Depend on Figures 8-10 Observations show that the optical imaging lens group in Example 1 has good imaging resolution, small optical system distortion and chromatic aberration across the entire field of view. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber optic scanner and has good imaging effect.

[0094] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element can be set on the first side of the optical imaging lens assembly, and the optical imaging lens assembly can be installed in the housing, so that the curved image formed by the image source (such as a fiber optic scanner) can be imaged on a plane to achieve clear imaging.

[0095] Example 3

[0096] Figure 11 This is a schematic diagram of an optical imaging lens assembly provided in Embodiment 3. The optical imaging lens assembly includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9, arranged coaxially along the optical axis from a first side to a second side. The first lens L1 and the second lens L2 form the front lens group, and the third lens L3 to the ninth lens L9 form the rear lens group. The focal lengths of the first lens L1 to the second lens L2 are positive and positive, respectively. The third lens L3 includes a first sub-lens L3-1 and a second sub-lens L3-2, both of which have negative focal lengths. The focal lengths of the fourth lens L4 to the ninth lens L9 are positive, positive, negative, positive, positive, and positive, respectively. Furthermore, the aperture is positioned on the first side of the optical imaging lens group. The image-side surface S1 of the first lens L1 and the image-side surface S3 of the second lens L2 are both convex. The object-side surface S2 of the first lens L1 is convex, and the object-side surface S4 of the second lens L2 is flat. The first sub-lens L3-1 and the second sub-lens L3-2 of the third lens L3 are both biconcave lenses. The image-side surface S9 of the fourth lens L4 is concave, and its object-side surface S10 is convex. The fifth lens L5 is a biconvex lens, and the sixth lens L6 is a biconcave lens. The fifth lens L5 and the sixth lens L6 are combined to form a cemented lens. The image-side surface S14 of the seventh lens L7 is concave, and its object-side surface S15 is convex. The image-side surface S16 of the eighth lens L8 is convex, and its object-side surface S17 is concave. The ninth lens L9 is meniscus and bends towards the curved image surface. The image-side surface S18 of the ninth lens L9 is convex, and its object-side surface S19 is concave. It should be noted that the surface shape of the lenses in the optical imaging lens group is not limited to the above description and can be adjusted appropriately. For example, the image side of the first lens L1 can be flat, the object side of the second lens L2 can be concave, the image side of the fourth lens L4 can be flat, and the image side of the seventh lens L7 can be flat or convex.

[0097] Furthermore, in this embodiment, the second side of the optical imaging lens group corresponds to the curved image at the light source end. The lens of the optical imaging lens group has an F / # of 1.86mm, a total focal length of -1mm, and a full field of view of 36 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 7:

[0099] Table 7 shows the relationship between the focal length of each lens element and the total focal length of the lens in this embodiment.

[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 for imaging curved surface images are shown in Table 8:

[0102] Table 8 Structural parameters of the optical imaging lens assembly in Example 3

[0103]

[0104]

[0105] It should be noted that Table 7 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 S1-19 indicates the surfaces from the first side to the second side; the optical surface with radius of curvature "Infinity" refers to a plane.

[0106] Furthermore, tests showed that when the image light corresponding to the scanning surface is projected using the aforementioned optical imaging lens group, its optical transfer function curve is as follows: Figure 12 As shown, the field distortion curve is as follows: Figure 13 As shown, the vertical axis color difference curve is as follows: Figure 14 As shown; among them, the Modulation Transfer Function (MTF) curve represents the overall resolution level of an optical system, the Field Curve Distortion curve represents the F-Tan (theta) distortion magnitude (percentage) under different field angles, and the Vertical Chromatic Aberration curve represents the magnitude of chromatic aberration in the direction perpendicular to the axial direction.

[0107] Depend on Figures 12-14 Observations show that the optical imaging lens group in Example 1 has good imaging resolution, small optical system distortion and chromatic aberration across the entire field of view. Therefore, the optical imaging lens group can clearly image the scanning surface image of the fiber optic scanner and has good imaging effect.

[0108] Of course, in practical applications, the optical imaging lens assembly may also include a display element, a housing, etc. The display element can be set on the first side of the optical imaging lens assembly, and the optical imaging lens assembly can be installed in the housing, so that the curved image formed by the image source (such as a fiber optic scanner) can be imaged on a plane to achieve clear imaging.

[0109] Scanning display device

[0110] The aforementioned optical imaging lens assembly can be used in conjunction with a fiber optic scanner (or a corresponding fiber optic scanning module) to constitute the scanning display device in the embodiments of this application (e.g., Figure 1a , 1bAs 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 1a , 1b The corresponding content will not be elaborated on here.

[0111] 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 field of projection, specifically configured and applied in vehicle projection. It can be configured not only in the vehicle, such as on the exterior of the vehicle body or in the relevant position of the head-up display, but also in the vehicle interior for projection display. The specific configuration can be flexibly set according to the display requirements of the vehicle projection.

[0112] In some embodiments, the scanning display device can be applied to vehicles, including but not limited to automobiles, motorcycles, electric bicycles, balance scooters, and skateboards. In some embodiments, the vehicle-mounted projection system can also be applied to other vehicles with transportation capabilities, such as aircraft, ships, and wheelchairs. Taking an automobile as a specific example, the optical imaging module of the scanning display device can be located at the door, front, or rear of the vehicle to project images onto the ground around the vehicle. It should be noted that the image corresponding to the imaging end is a planar image, and the corresponding planar image carrier can be such as a projection screen, a screen, the ground, or a glass surface. It should also be noted that in specific applications of the scanning display device, the number of scanning display devices can be one or more groups. When the scanning display devices are located at different positions on the carrier (e.g., a vehicle), the specifications of the fiber optic scanner, the distribution of each lens in the optical imaging lens group, and the parameters can be adaptively adjusted according to the specific scenario.

[0113] 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.

[0114] 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.

[0115] 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 front lens group and a rear lens group arranged coaxially along a first side to a second side. The first side is 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 optic scanner. The front lens group has a positive focal length, receives light from the first side, and converts it into an inverted and reduced intermediate image, which is located between the front lens group and the rear lens group; The rear lens group has a positive focal length, and the image-side focal plane of the rear lens group is located on the object-side of the intermediate image, thus converting the intermediate image into an inverted real image. The total focal length of the optical imaging lens group is negative, wherein the focal length ratio of the front lens group to the rear lens group is in the range of 1.3 to 2.

61.

2. The optical imaging lens assembly according to claim 1, characterized in that, in, The focal length range of the front lens group is 2.17 to 2.

72.

3. The optical imaging lens assembly according to claim 2, characterized in that, The front lens group includes a first lens and a second lens arranged along the optical axis from the first side to the second side. The optical power of the first lens and the second lens is positive. The image-side surface of the first lens is convex, the image-side surface of the second lens is convex, and the object-side surface of the second lens is concave.

4. The optical imaging lens assembly according to claim 1, characterized in that, The focal length range of the rear lens group is 0.83 to 2.

1.

5. The optical imaging lens assembly according to claim 4, characterized in that, The rear lens group includes a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged along the optical axis from the first side to the second side. The optical powers of the third lens to the ninth lens are negative, positive, positive, negative, positive, positive, and positive, respectively. The third lens is an aspherical lens that is curved toward the curved image surface. The object side of the third lens is a concave aspherical surface, and the image side of the third lens is a curved aspherical surface. The absolute value of the ratio of the total focal length of the third lens to the total focal length of the optical imaging lens group is in the range of 0.97 to 3.

09.

6. The optical imaging lens assembly according to claim 4, characterized in that, The rear lens group includes a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged along the optical axis from the first side to the second side. The optical powers of the fourth lens to the ninth lens are positive, positive, negative, positive, positive, and positive, respectively. The third lens includes two lenses, both of which are biconcave lenses.

7. The optical imaging lens assembly according to claim 5 or 6, characterized in that, The image-side surface of the fourth lens is either flat or concave, and the object-side surface of the fourth lens is convex; the image-side surface of the fifth lens is convex, and the object-side surface of the fifth lens is either convex or flat; the image-side surface of the sixth lens is either flat or concave, and the object-side surface of the sixth lens is concave; or, the fifth lens is a biconvex lens, the sixth lens is a biconcave lens, and the fifth and sixth lenses form a cemented lens; the object-side surface of the seventh lens is convex; the image-side surfaces of the eighth and ninth lenses are convex, and the object-side surfaces of the eighth and ninth lenses are concave.

8. The optical imaging lens assembly according to claim 7, characterized in that, The ratio of the focal length of the sixth lens to the total focal length of the optical imaging lens group is in the range of 0.68 to 1.46, and the optical power of the object side of the sixth lens is in the range of -2.026 to -1.

28.

9. The optical imaging lens assembly according to claim 8, characterized in that, The total optical power of the seventh lens, the eighth lens, and the ninth lens is in the range of 0.67 to 0.

93.

10. A scanning display device, characterized in that, The invention includes a fiber optic scanner and an optical imaging lens group according to any one of claims 1 to 9, wherein the fiber optic scanner is used to scan and emit light to display an image, and the optical imaging lens group is used to magnify and project the scanning surface corresponding to the light emitted by the fiber optic scanner. The fiber optic scanner includes an actuator and an optical fiber fixed to the actuator. The portion of the optical fiber extending beyond the actuator forms an optical fiber cantilever, which performs two-dimensional scanning under the drive of the actuator.

Images