A large-aperture low-haze pixelized vehicle-mounted projection vehicle lamp lens

Abstract

The application provides a large-aperture low-heterochromatic light pixelized vehicle-mounted projection vehicle lamp lens, and belongs to the technical field of optical lenses. The projection lens comprises, in sequence from the object side to the image side along the optical axis, a first lens with positive focal power, a second lens with negative focal power, a third lens with positive focal power and a pixel light source; wherein an aperture diaphragm is arranged between the first lens and the second lens, a vignetting diaphragm is arranged between the second lens and the third lens, and a stray light elimination diaphragm is arranged between the third lens and the light source. Through the positive-negative-positive symmetrical three-piece structure, the triple diaphragm design and the multi-parameter collaborative constraint of Abbe number, refractive index, air gap and bending degree, the application realizes the projection lens with a large aperture (F#<0.65), high light efficiency, high definition, low stray light and compact structure, and is especially suitable for a million-pixel Micro LED vehicle lamp and has good vehicle-mounted environmental adaptability and manufacturability.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, specifically to a large-aperture, low-stray-light pixelated automotive projection headlight lens. Background Technology

[0002] With the development of intelligent driving technology, in-vehicle pixel lights have become the core development direction of the industry. Through Micro / Mini LED pixel light sources, they can realize functions such as road ADAS marking projection, adaptive lighting, and human-vehicle interaction, which puts extremely high requirements on the optical performance of the projection lens.

[0003] Existing automotive pixel headlight projection lenses suffer from the following unresolved core defects: (1) Bulky structure and high cost: It generally uses a combination of 4 or more spherical lenses to correct aberrations, and the total length of the lens exceeds 60mm, which cannot be adapted to the flat shape of the vehicle headlight. In addition, the cost of lenses, processing and assembly is high, and the mass production yield is low. (2) Failure to suppress stray light: Without a dedicated stray light suppression structure, stray light reflected from the side of the LED chip, the packaging structure, and the secondary reflection stray light from the lens surface directly enters the imaging optical path, resulting in ghosting and blurred image quality, which seriously affects the recognizability of the projected sign. (3) Difficulty in correcting aberrations with large aperture: The difficulty of correcting chromatic aberration, astigmatism, field curvature and distortion in large aperture (F# < 0.7) systems increases exponentially. Existing technologies cannot achieve full-field high-definition imaging with large apertures, and serious color fringing, blurring and distortion appear at the edges of the image. (4) Poor adaptability to vehicle environment: Ordinary plastic / glass lenses are prone to thermal expansion and contraction and refractive index drift in vehicle environment of -40℃~120℃, which leads to aberration deterioration and cannot meet the stability requirements of vehicle safety regulations. (5) Low light source utilization: The traditional lens optical path design is unreasonable, resulting in a large loss of light flux. The utilization rate of Micro LED light source is less than 30%, which cannot meet the brightness requirements of vehicle lighting.

[0004] Therefore, there is an urgent need for a compact, large-aperture, high-efficiency, low-stray-light, high-definition and stable automotive pixel headlight projection lens to solve the core pain points of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to overcome at least one technical problem existing in the prior art and to provide a large aperture, low stray light pixelated vehicle projection headlight lens.

[0006] On one hand, embodiments of the present invention provide a large-aperture, low-stray-light pixelated automotive projection headlight lens. The lens includes: a pixel light source, a third lens, a second lens, and a first lens arranged sequentially along the light path from the light source side to the light-emitting side, and three aperture stops. The first lens is a positive power biconvex lens, the second lens is a negative power concave-convex lens, and the third lens is a positive power convex-concave lens. The first lens, the second lens, and the third lens constitute a positive-negative-positive lens architecture. The three aperture stops include an aperture stop disposed between the first lens and the second lens, a vignetting stop disposed between the second lens and the third lens, and a stray-light reduction stop disposed between the third lens and the pixel light source. The Abbe number of the first lens, the second lens, and the third lens all satisfy preset Abbe number constraints. The refractive index of the first lens, the refractive index of the second lens, and the refractive index of the third lens all satisfy preset refractive index constraints. The air gaps at the edges of the first lens and the second lens, and the air gaps at the edges of the second lens and the third lens satisfy preset air gap constraints.

[0007] Furthermore, the object-side surface of the first lens is convex, and the image-side surface is convex; the object-side surface of the second lens is concave, and the image-side surface is convex; the object-side surface of the third lens is convex, and the image-side surface is concave.

[0008] Furthermore, the aperture stop size determines the aperture value of the projection vehicle light lens, which is used to control the amount of light entering the system and prevent stray light reflected from the lens edge from entering the main optical path; the vignetting stop is used to intercept harmful stray light in the off-axis field of view, eliminate imaging vignetting, and ensure uniform brightness across the entire field of view; the stray light blocking stop is used to block stray light emitted from the side of the pixel light source or the encapsulation structure that is not in the main imaging optical path.

[0009] Furthermore, the preset Abbe number constraint conditions include: the Abbe number of the first lens is Vd1, the Abbe number of the second lens is Vd2, and the Abbe number of the third lens is Vd3, satisfying: Vd1-Vd2>the first Abbe number threshold, and the second Abbe number threshold>Vd3-Vd2>the first Abbe number threshold.

[0010] Furthermore, the preset refractive index constraint conditions include: the refractive index of the first lens is n1, the refractive index of the second lens is n2, and the refractive index of the third lens is n3, satisfying: n3-n1>first refractive index threshold, and the value range of n2 is: second refractive index threshold ≤ n2 ≤ third refractive index threshold.

[0011] Further, the preset air gap constraint conditions include: the edge air gap between the first lens and the second lens is E12, and the edge air gap between the second lens and the third lens is E23, satisfying: E12 > E23.

[0012] Further, the third lens needs to satisfy a bending constraint, and the bending constraint includes: the focal length of the third lens is F3, and the curvature radius of its object side is R31, satisfying: or , and a2 is greater than a1.

[0013] Further, the first lens and the second lens are plastic aspherical lenses; the third lens is a glass spherical lens.

[0014] Further, the aspherical surface types of the first lens and the second lens are defined by the following formula: ; In the formula, Z(h) is the surface sag at the radial distance h, c is the reciprocal of the curvature radius, k is the conic coefficient, and A4, A6, A8, and A10 are aspherical coefficients.

[0015] Further, the projection headlight lens has a large aperture, low distortion, and a compact structure, and is adapted to a high pixel density light source; wherein, the aperture value of the projection headlight lens satisfies: F# < 0.65; the optical distortion of the projection headlight lens is less than 2%; the total length TTL of the projection headlight lens satisfies: TTL < 60 mm; the effective focal length EFL of the projection headlight lens satisfies: 15 mm < EFL < 35 mm; the pixel light source is a Micro LED or a Mini LED, and the number of its pixels is greater than 15000.

[0016] Compared with the prior art, the beneficial effects of the present invention are: (1) By reasonably distributing the optical power of the three lenses, using a (positive-negative-positive) symmetric lens architecture, and using a glass lens that can be coated, the optical efficiency of the entire system is greatly improved.

[0017] (2) Only introducing two high-performance heat-resistant plastic aspherical lenses can effectively reduce the influence of aberrations such as astigmatism, field curvature, distortion, and chromatic aberration of magnification in the high-temperature situation of the vehicle, and obtain uniform high-definition image quality within the entire viewing field. On the premise of ensuring the core performance, the material cost and lens processing cost are effectively reduced, the lens weight is reduced, the total length of the system is reduced, and the structure is more compact; (3) Adding two additional diaphragms can greatly reduce the stray light caused by the reflection of the light source surface and the inner and outer surfaces of the lens, and reduce the influence of stray light on the overall projection; (4) The last lens adopts a concave design, which helps to optimize the assembly process and improve the manufacturability of the system compared with other technologies. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is a schematic diagram of a large-aperture, low-stray-light pixelated vehicle projection headlight lens structure provided in Embodiment 1 of the present invention.

[0020] Figure 2 This is a lateral color difference simulation image provided in Embodiment 1 of the present invention.

[0021] Figure 3 This is a simulation diagram of field curvature and distortion provided in Embodiment 1 of the present invention.

[0022] Figure 4 This is a full-field MTF simulation diagram provided in Embodiment 1 of the present invention.

[0023] Figure 5 This is a point-by-point diagram simulation diagram provided in Embodiment 1 of the present invention.

[0024] The attached figures are labeled as follows: First lens-1; Second lens-2; Third lens-3; Pixel light source-4; Aperture stop-5; Vignette stop-6; Anti-stray stop-7; Object side of first lens-11; Image side of first lens-12; Object side of second lens-21; Image side of second lens-22; Object side of third lens-31; Image side of third lens-32. Detailed Implementation

[0025] Before discussing the exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but may also have additional steps not included in the figures. The process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0026] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] The present invention will now be described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0028] For ease of understanding, the following technical terms are explained here: Optical power: The ability of a lens to deflect light rays; positive = convergent light rays, negative = divergent light rays. F-number (F#): Aperture value = focal length / aperture diameter. The smaller the number, the larger the aperture, and the more light enters. Abbe number (Vd): Dispersion coefficient. The larger the value, the smaller the light dispersion, and the image has no color edges. Refractive index (n): The ability of a medium to deflect light; the larger the value, the stronger the light-gathering ability. MTF: Modulation Transfer Function, the closer the value is to 1, the clearer the image; Distortion: The degree of image deformation; the smaller the value, the more regular the image. Aspherical surface: A non-spherical curved surface, one sheet can replace multiple spherical sheets to correct aberrations; Stray light: Scattered / reflected light outside the imaging optical path can cause ghosting and blurry images.

[0029] Example 1 To facilitate understanding, the inventive concept will be described in its entirety before detailing the embodiments of the present invention: The present invention proposes a novel three-element projection lens design paradigm: Unlike the existing technology that corrects aberrations by stacking more lenses, the present invention provides basic aberration correction capabilities through a 'positive-negative-positive' symmetrical architecture. Furthermore, through the functional division of the three aperture stops (aperture stop to control light intensity, vignetting stop to clear off-axis light, and stray light elimination stop to isolate stray light), combined with a plastic aspherical surface and glass hybrid material, and the multi-parameter synergistic constraints of Abbe number / refractive index / air gap / curvature, the present invention achieves excellent performance of distortion <2%, TTL <60mm, and MTF >0.5 across the entire field of view using only three lenses at a large aperture of F# <0.65.

[0030] The specific implementation method is as follows: like Figure 1The diagram shown is a schematic of a large-aperture, low-stray-light pixelated vehicle projection headlight lens structure provided by the present invention.

[0031] As an example, the lens includes: a pixel light source 4, a third lens 3, a second lens 2, and a first lens 1 arranged sequentially along the optical path from the light source side to the light-emitting side, and three aperture stops; the first lens 1 is a positive power biconvex lens, the second lens 2 is a negative power concave-convex lens, and the third lens 3 is a positive power convex-concave lens, the first lens 1, the second lens 2, and the third lens 3 forming a positive-negative-positive lens architecture; the three aperture stops include an aperture stop 5 disposed between the first lens 1 and the second lens 2, a vignetting stop 6 disposed between the second lens 2 and the third lens 3, and a stray light removal stop 7 disposed between the third lens 3 and the pixel light source 4; the Abbe number of the first lens 1, the second lens 2, and the third lens 3 all satisfy a preset Abbe number constraint condition; the refractive index of the first lens 1, the second lens 2, and the third lens 3 all satisfy a preset refractive index constraint condition; the air gaps at the edges of the first lens 1 and the second lens 2, and the air gaps at the edges of the second lens 2 and the third lens 3 satisfy a preset air gap constraint condition.

[0032] In some feasible implementations, the object-side surface 11 of the first lens 1 is convex and the image-side surface 12 is convex; the object-side surface 21 of the second lens 2 is concave and the image-side surface 22 is convex; the object-side surface 31 of the third lens 3 is convex and the image-side surface 32 is concave.

[0033] Preferably, the optical path is as follows: reverse projection optical path: pixel light source → third lens 3 → second lens 2 → first lens 1 → external projection. The light from the LED surface light source is first coupled and converged by the third lens 3, then the aberration is corrected by the second lens 2, and finally shaped and emitted by the first lens 1. Compared with the forward optical path, the light source coupling efficiency is improved by 40%+, which is suitable for the small-sized light-emitting surface of Micro LED.

[0034] In some feasible implementations, the aperture stop 5 determines the aperture value of the projection vehicle light lens, which is used to control the amount of light entering the system and prevent stray light reflected from the lens edge from entering the main optical path; the vignetting stop 6 is used to intercept harmful stray light in the off-axis field of view, eliminate imaging vignetting, and ensure uniform brightness across the entire field of view; the stray light blocking stop 7 is used to block stray light emitted from the side or encapsulation structure of the pixel light source 4 in the non-imaging main optical path.

[0035] Specifically, aperture stop 5 is positioned between the first lens 1 and the second lens 2 to control the system's F-number and light transmission, preventing stray light reflected from the lens edges from entering the main optical path; vignetting stop 6 is positioned between the second lens 2 and the third lens 3 to intercept harmful stray light in the off-axis field of view, eliminate imaging vignetting, and ensure uniform brightness across the entire field of view; stray light elimination stop 7 is positioned between the third lens 3 and the light source 4 to block non-imaging stray light from the side of the LED chip and the packaging structure at the source, completely eliminating stray light interference.

[0036] In some feasible implementations, the preset Abbe number constraint conditions include: the Abbe number of the first lens 1 is Vd1, the Abbe number of the second lens 2 is Vd2, and the Abbe number of the third lens 3 is Vd3, satisfying: Vd1 - Vd2 > the first Abbe number threshold, and the second Abbe number threshold > Vd3 - Vd2 > the first Abbe number threshold. Preferably, the first Abbe number threshold is 10, and the second Abbe number threshold is preferably 20. It should be noted that the first and second Abbe number thresholds here are only examples and are not intended to limit the application; those skilled in the art can modify their specific values ​​based on actual needs during practical application.

[0037] Specifically, the Abbe number constraint is: Vd1-Vd2>10, 20>Vd3-Vd2>10, which effectively corrects axial chromatic aberration and magnification chromatic aberration, avoiding color edges in the image. That is, the first lens 1 has a high Abbe number (low dispersion) + the second lens 2 has a low Abbe number (high dispersion): complementary correction of axial chromatic aberration, avoiding color edges in the image; the Abbe number difference between the third lens 3 and the second lens 2 is controlled: correction of magnification chromatic aberration, ensuring no chromatic aberration across the entire field of view.

[0038] In some feasible implementations, the preset refractive index constraint conditions include: the refractive index of the first lens 1 is n1, the refractive index of the second lens 2 is n2, and the refractive index of the third lens 3 is n3, satisfying: n3 - n1 > first refractive index threshold, and the value range of n2 is: second refractive index threshold ≤ n2 ≤ third refractive index threshold. Preferably, the first refractive index threshold is 0.1, the second refractive index threshold is 1.4, and the third refractive index threshold is 1.7. It should be noted that the first, second, and third refractive index thresholds here are only examples and are not intended to limit the application; those skilled in the art can modify their specific values ​​based on actual needs during practical application.

[0039] Specifically, the refractive index constraints are: n3-n1>0.1, 1.4≤n2≤1.7, to improve the light-gathering ability of the third lens and balance lightweight design with aberration correction. In other words, the third lens uses high-refractive-index glass (≤1.8) for extremely strong light-gathering ability, ensuring a large aperture; the L1 / L2 plastics have moderate refractive indices for lightweight design and ease of processing, avoiding excessive refractive index differences that could lead to manufacturing failures.

[0040] In some feasible implementations, the preset air gap constraint conditions include: the edge air gap between the first lens 1 and the second lens 2 is E12, and the edge air gap between the second lens 2 and the third lens 3 is E23, satisfying: E12>E23.

[0041] Specifically, the edge gap constraint is E12 > E23 to avoid lens edge interference and optimize the assembly process; wherein, the edge air gap refers to the axial distance between the opposite surfaces of two adjacent lenses at the maximum effective light transmission aperture.

[0042] In some feasible implementations, the third lens 3 needs to satisfy a bending constraint, which includes: the focal length of the third lens 3 is F3, and the radius of curvature of its object side surface 31 is R31, satisfying: or And a2 is greater than a1. Among them, a1 is preferably 1.3 and a2 is preferably 1.6.

[0043] Specifically, |R31 / F3| < 1.3 or |R31 / F3| > 1.6. That is, controlling the curvature of the three surfaces of the third lens reduces the difficulty of glass lens processing; optimizing field curvature and astigmatism improves the consistency of center and edge imaging.

[0044] In some feasible implementations, the first lens 1 and the second lens 2 are plastic aspherical lenses; the third lens 3 is a glass spherical lens.

[0045] Specifically, the first lens 1 is made of PMMA plastic with a light transmittance of 92%+, easily injection molded into an aspherical surface, and has extremely low cost; it is lightweight, reducing the overall weight of the lens. The second lens 2 is made of PC heat-resistant plastic, with a temperature resistance of -40℃ to 120℃, suitable for high-temperature automotive applications; it is impact-resistant, and the aspherical surface has high processing precision. The third lens 3 is made of high-refractive-index flint glass, which can be coated with an anti-reflective coating, improving light efficiency by 15%+; it has excellent heat resistance, with no refractive index drift at high temperatures, ensuring stable imaging.

[0046] More specifically, the parameters of the image side and object side of this lens are shown in Table 1 below: Table 1:

[0047] In some feasible implementations, the aspherical surface profiles of the first lens 1 and the second lens 2 are defined by the following formula: ; In the formula, Z(h) is the surface sag at a radial distance h, c is the reciprocal of the radius of curvature, k is the conic coefficient, and A4, A6, A8, and A10 are aspherical coefficients.

[0048] Specifically, the aspherical coefficients are as shown in Table 2: Table 2:

[0049] In some feasible embodiments, the projection headlight lens has a large aperture, low distortion, and a compact structure, and is adapted to a high pixel density light source; wherein, the aperture value of the projection headlight lens satisfies: F# < 0.65; the optical distortion of the projection headlight lens is less than 2%; the total length TTL of the projection headlight lens satisfies: TTL < 60 mm; the effective focal length EFL of the projection headlight lens satisfies: 15 mm < EFL < 35 mm; the pixel light source 4 is a Micro LED or a Mini LED, and the number of its pixels is greater than 15000.

[0050] To intuitively reflect the advantages of this lens, this embodiment further describes the present invention in detail with reference to the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0051] In this embodiment, an optical design software is used for modeling, ray tracing, and performance simulation. A reverse optical path design is adopted, that is, the projection road surface is used as the object surface, and the pixel light source surface is used as the image surface for system optimization and evaluation.

[0052] The simulation conditions are as follows: the working wavelength band is the visible light band, and three characteristic wavelengths of 0.460 , 0.525 , 0.617 are taken; the effective focal length EFL of the system = 25 mm; the aperture F# = 0.64; the total length TTL of the lens = 54 mm; the maximum object field height is 1299.432 mm; multi-field uniform sampling is adopted, and full-aperture ray tracing is performed on the meridional plane and sagittal plane rays.

[0053] The large-aperture pixelated vehicle-mounted projection headlight lens in this embodiment includes a pixel light source, an anti-ghosting diaphragm, a third lens, a vignetting diaphragm, a second lens, an aperture diaphragm, and a first lens arranged in sequence along the light propagation direction. Among them, the first lens has a positive optical power and is a double-convex plastic aspherical lens; the second lens has a negative optical power and is a concave-convex heat-resistant plastic aspherical lens; the third lens has a positive optical power and is a convex-concave high-refractive-index glass lens. The aperture diaphragm is arranged between the first lens and the second lens, the vignetting diaphragm is arranged between the second lens and the third lens, and the anti-ghosting diaphragm is arranged close to the pixel light source.

[0054] Under the above structure and simulation conditions, the optical performance of the system is evaluated, and the results are as follows: As Figure 2The diagram shown is a lateral chromatic aberration diagram for this embodiment. The vertical axis represents the object-side field of view height, and the horizontal axis represents the image-side lateral chromatic aberration. Within the entire field of view, the lateral offsets of the red, green, and blue wavelengths are small, resulting in sufficient chromatic aberration correction and no obvious color edges in the image, meeting the requirements for in-vehicle high-definition projection. Specifically, within the entire field of view, the curves for the three characteristic wavelengths (red 617nm, green 525nm, and blue 460nm) unfold symmetrically in a V-shape towards both sides of the horizontal axis, with the lateral offset at the maximum field of view being only ±30. Compared to a 1.3m projection screen, the relative offset is only 0.0023%, which is completely invisible to the naked eye and eliminates the problem of colored edges.

[0055] like Figure 3 The figure shows the field curvature and distortion diagrams of this embodiment. As can be seen from the figure, this embodiment exhibits excellent field curvature and astigmatism control, high focus consistency across the entire field of view, optical distortion of less than 2%, and a regular projected image without significant deformation. Specifically, in the field curvature diagram on the left, the maximum offset of the T / S curves for all wavelengths across the entire field of view is far less than 0.5mm, and the astigmatism value is far less than 0.1mm; in the distortion diagram on the right, the three wavelength curves across the entire field of view almost perfectly match the 0% vertical line, the maximum distortion is far less than 2%, and the actual maximum distortion is approximately 0, eliminating barrel / pincushion distortion.

[0056] like Figure 4 The figure shows the MTF curves for the entire field of view in this embodiment at a spatial frequency of 6.25 lp / mm. The MTF values ​​for the entire field of view are all greater than 0.5. The central field of view is close to the diffraction limit, while the edge fields of view maintain high contrast, resulting in clear and sharp imaging. Specifically, the central field of view MTF ≈ 0.88~0.9, close to the diffraction limit; the middle field of view MTF ≈ 0.73; and the edge field of view (at the maximum field of view of 1300mm) MTF ≥ 0.58, far exceeding the industry standard of 0.5. The T / S curve difference for the entire field of view is extremely small, and astigmatism is completely suppressed.

[0057] like Figure 5 The diagram shown is a full field-of-view dot plot of this embodiment. The light spots in each field of view are concentrated and symmetrical, with a small RMS radius, resulting in excellent aberration control. Stable and clear imaging is achieved from the center to the edge, with minimal stray light interference. Specifically, the RMS radius of the central field of view is approximately 17.8. Compared to Micro LED pixel size (10-20 Highly matched; edge field of view RMS radius ≈ 44.6 The aberration on the side facing the road surface is approximately 12.3mm, which is much smaller than the pixel recognition requirement for vehicle-mounted projection. The light spot is symmetrical across the entire field of view, and the three wavelengths highly overlap.

[0058] The above results show that this embodiment achieves high light efficiency, low stray light, low distortion, and high image quality projection effects under the condition of a large aperture of F#<0.65. The lens structure is compact and suitable for use in vehicle-mounted pixelated lighting and ADAS projection systems.

[0059] In other embodiments, the lens material, radius of curvature, and aspheric coefficient can be adjusted while satisfying the corresponding constraints. For example, the first lens 1 can be made of other high Abbe number plastic materials, the second lens 2 can be made of other low Abbe number plastic materials, and the third lens 3 can be made of other high refractive index glass materials. As long as the constraints such as Abbe number difference, refractive index difference, air gap ratio, and degree of curvature are satisfied, they all fall within the protection scope of this invention.

[0060] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, based on the guidance provided in this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A large-aperture, low-stray-light pixelated automotive projection headlight lens, characterized in that, The lens includes: a pixel light source (4), a third lens (3), a second lens (2), a first lens (1) arranged sequentially from the light source side to the light-emitting side along the light path, and three aperture stops; The first lens (1) is a positive power biconvex lens, the second lens (2) is a negative power concave-convex lens, and the third lens (3) is a positive power convex-concave lens. The first lens (1), the second lens (2) and the third lens (3) constitute a positive-negative-positive lens structure. The three aperture stops include an aperture stop (5) disposed between the first lens (1) and the second lens (2), a vignetting stop (6) disposed between the second lens (2) and the third lens (3), and a stray light removal stop (7) disposed between the third lens (3) and the pixel light source (4). The Abbe number of the first lens (1), the Abbe number of the second lens (2) and the Abbe number of the third lens (3) all satisfy the preset Abbe number constraint conditions. The refractive index of the first lens (1), the refractive index of the second lens (2) and the refractive index of the third lens (3) all satisfy the preset refractive index constraint conditions; The air gap between the edges of the first lens (1) and the second lens (2), and the air gap between the edges of the second lens (2) and the third lens (3) satisfy the preset air gap constraint conditions.

2. The large-aperture, low-stray-light pixelated automotive projection headlight lens according to claim 1, characterized in that, The object side (11) of the first lens (1) is convex and the image side (12) is convex; the object side (21) of the second lens (2) is concave and the image side (22) is convex; the object side (31) of the third lens (3) is convex and the image side (32) is concave.

3. The large-aperture, low-stray-light pixelated automotive projection headlight lens according to claim 1, characterized in that, The aperture stop (5) determines the aperture value of the projection vehicle light lens, which is used to control the amount of light entering the system and prevent stray light reflected from the lens edge from entering the main light path; the vignetting stop (6) is used to intercept harmful stray light in the off-axis field of view, eliminate imaging dark angle, and ensure uniform brightness across the entire field of view; the stray light blocking stop (7) is used to block stray light emitted from the side of the pixel light source (4) or the encapsulation structure in the non-imaging main light path.

4. The large-aperture, low-stray-light pixelated automotive projection headlight lens according to claim 1, characterized in that, The preset Abbe number constraints include: The Abbe number of the first lens (1) is Vd1, the Abbe number of the second lens (2) is Vd2, and the Abbe number of the third lens (3) is Vd3, satisfying that: Vd1-Vd2>the first Abbe number threshold, and the second Abbe number threshold>Vd3-Vd2>the first Abbe number threshold.

5. The large-aperture, low-stray-light pixelated automotive projection headlight lens according to claim 1, characterized in that, The preset refractive index constraint conditions include: the refractive index of the first lens (1) is n1, the refractive index of the second lens (2) is n2, and the refractive index of the third lens (3) is n3, satisfying: n3-n1>first refractive index threshold, and the value range of n2 is: second refractive index threshold≤n2≤third refractive index threshold.

6. The large-aperture, low-stray-light pixelated automotive projection headlight lens according to claim 1, characterized in that, The preset air gap constraint conditions include: the edge air gap between the first lens (1) and the second lens (2) is E12, and the edge air gap between the second lens (2) and the third lens (3) is E23, satisfying: E12>E23.

7. The large-aperture, low-stray-light pixelated automotive projection headlight lens according to claim 1, characterized in that, The third lens (3) needs to satisfy a bending constraint, which includes: the focal length of the third lens (3) is F3, and the radius of curvature of its object side surface (31) is R31, satisfying: or And a2 is greater than a1.

8. The large-aperture, low-stray-light pixelated automotive projection headlight lens according to claim 1, characterized in that, The first lens (1) and the second lens (2) are plastic aspherical lenses; the third lens (3) is a glass spherical lens.

9. The large-aperture, low-stray-light pixelated automotive projection headlight lens according to claim 8, characterized in that, The aspherical surface profiles of the first lens (1) and the second lens (2) are defined by the following formula: ； In the formula, Z(h) is the surface sag at the radial distance h, c is the reciprocal of the radius of curvature, k is the conic coefficient, and A4, A6, A8, A10 are aspherical coefficients.

10. The large-aperture, low-stray-light pixelated automotive projection headlight lens according to claim 1, characterized in that, The projection headlight lens has a large aperture, low distortion, and a compact structure, and is adapted to a high pixel density light source; wherein, the aperture value of the projection headlight lens satisfies: F# < 0.65; the optical distortion of the projection headlight lens is less than 2%; the total length TTL of the projection headlight lens satisfies: TTL < 60 mm; the effective focal length EFL of the projection headlight lens satisfies: 15 mm < EFL < 35 mm; the pixel light source (4) is a Micro LED or a Mini LED, and the number of its pixels is greater than 15000.

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