Vehicle projection lens and lamp for vehicle

Abstract

A vehicle projection lens includes a cemented lens composed of an aspherical first lens, a spherical second lens, and a spherical third lens arranged sequentially from the magnifying side to the reducing side of the projection lens, and a spherical fourth lens. The aperture value (F-number) of the projection lens is less than or equal to 0.8. The field of view (FOV) of the projection lens is between 14 degrees and 44 degrees. The projection lens is essentially composed of four lenses, and the refractive powers of the four lenses are positive, negative, positive, and positive in sequence.

Description

Technical Field

[0001] This invention relates to a projection lens, and more particularly to a projection lens applicable to vehicle headlights. Prior Technology

[0002] The function of vehicle lights is not only to help drivers identify the environment ahead, but also to inform those around them of the driver's current location, achieving a considerable level of warning. Currently, there are smart vehicle lights on the market that adjust based on ambient light and driving conditions to reduce glare for oncoming vehicles or project directional images to assist driving. Therefore, there is a current need for a projection lens that can meet traffic regulations regarding illumination range while achieving good resolution and minimal distortion. Summary of the Invention

[0003] Other objects and advantages of the present invention can be further understood from the technical features disclosed in the embodiments of the present invention.

[0004] One embodiment of the present invention provides a vehicle projection lens, comprising a cemented lens consisting of an aspherical first lens, a spherical second lens, and a spherical third lens arranged sequentially from the magnifying side to the reducing side of the projection lens, and a spherical fourth lens. The aperture value (F-number) of the projection lens is less than or equal to 0.8. The field of view (FOV) of the projection lens is between 14 degrees and 44 degrees. The projection lens is essentially composed of four lenses, and the refractive powers of the four lenses are positive, negative, positive, and positive in sequence.

[0005] Another embodiment of the present invention provides a vehicle projection lens, comprising, in sequence along one direction, an aspherical first lens, a second lens with negative refractive power, a third lens with refractive power, and a fourth lens with positive refractive power. The fourth lens is the lens closest to the lens's narrowing side among the four lenses. The projection lens satisfies the following conditions: an aperture value (F-number) less than or equal to 0.8, and a field of view (FOV) between 14 and 44 degrees. The projection lens is essentially composed of four lenses, and the first lens is the one with the largest outer diameter among the four lenses.

[0006] Another embodiment of the present invention provides an automotive device comprising an LED array light source, a projection lens essentially composed of four lenses, and a headlight cover. The projection lens is located downstream of the light source's optical path and sequentially includes an aspherical first lens, a second lens with negative refractive power, a third lens with refractive power, and a fourth lens with positive refractive power. The fourth lens is the lens closest to the light source among the four lenses. The headlight cover is located downstream of the projection lens's optical path. The projection lens has an f-number less than or equal to 0.8 and a field of view (FOV) between 14 and 44 degrees.

[0007] Based on the above, the automotive projection lens and automotive device of the present invention have at least one of the following advantages. Through the design of the embodiments of the present invention, a lens design that meets traffic regulations in terms of illumination range, high resolution, low distortion, and miniaturization can be provided, and that offers lower manufacturing costs and better image quality for application in automotive headlights can be achieved.

[0008] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings for detailed explanation. Simple Explanation of the Diagram

[0009] Figure 1 is a schematic diagram of a vehicle device according to an embodiment of the present invention. Figure 2 is a schematic diagram of the optical structure of the vehicle projection lens according to the first embodiment of the present invention. Figure 3 is a schematic diagram of the optical structure of the vehicle projection lens according to the second embodiment of the present invention. Figure 4 is a schematic diagram of the optical structure of the vehicle projection lens according to the third embodiment of the present invention. Figure 5 is a schematic diagram of the optical structure of the vehicle projection lens according to the fourth embodiment of the present invention. Figure 6 is a schematic diagram of the optical structure of the vehicle projection lens according to the fifth embodiment of the present invention. Figure 7 is a schematic diagram of the optical structure of the vehicle projection lens according to the sixth embodiment of the present invention. Figure 8 is a schematic diagram of the optical structure of the vehicle projection lens according to the seventh embodiment of the present invention. Figure 9 is a schematic diagram of the optical structure of the vehicle projection lens according to the eighth embodiment of the present invention. Figure 10 is a schematic diagram of the optical structure of a vehicle projection lens according to the ninth embodiment of the present invention. Figure 11 is the modulation transfer function curve of the automotive projection lens in Figure 2, and Figure 12 is the distortion diagram of the automotive projection lens in Figure 2. Figure 13 is the modulation transfer function curve of the automotive projection lens in Figure 9, and Figure 14 is the distortion diagram of the automotive projection lens in Figure 9. Figure 15 is a schematic diagram of a plastic lens with a chamfered edge. Implementation

[0010] The terms "first" and "second" used in the following embodiments are for the purpose of identifying the same or similar technical content, features, and effects described above, as well as other technical contents, features, and effects of the present invention, which will be clearly presented in the following detailed description of the embodiments with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front, or back, are only for reference to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the present invention. To show the features of this embodiment, only the structures related to this embodiment are shown, and other structures are omitted.

[0011] The lens referred to in this invention is an element made of a partially or wholly permeable material and possessing refractive power, typically composed of glass or plastic. It may include a general lens, a prism, an aperture, a cylindrical lens, a biconical lens, a lenticular lens array, a wedge lens, a wedge plate, or a combination of the foregoing.

[0012] When a lens is used in a projection system, the magnifying side refers to the side of the optical path closer to the imaging surface (such as the screen), while the shrinking side refers to the side of the optical path closer to the light source or light valve.

[0013] The object-side (or image-side) of a lens has a convex (or concave) portion located in a certain region, meaning that the region is more "outwardly convex" (or "inwardly concave") in a direction parallel to the optical axis compared to the radially adjacent outer region.

[0014] Figure 1 is a schematic diagram of a vehicle lighting device according to an embodiment of the present invention. Referring to Figure 1, the vehicle lighting device 100 of this embodiment includes an image source 120, a vehicle projection lens 10, and a vehicle lighting cover (not shown in the figure). The image source 120 includes a light source such as an LED array, a micro LED array (µ-LED), a laser, or an LED. In addition, in this embodiment, a prism 130 (or a reflector) can be provided on the reduced side of the vehicle projection lens 10. The image beam I can be deflected by the prism 130 (or the reflector) before entering the vehicle projection lens 10, thereby obtaining a deflected light path to reduce the overall space occupied by the vehicle lighting device 100. In one embodiment, the image source 120 can be provided on the reduced side of the vehicle projection lens 10, directly facing the vehicle projection lens 10, and the image beam I directly enters the vehicle projection lens 10 from the image source 120.

[0015] Figure 2 is a schematic diagram of the optical structure of the vehicle projection lens according to the first embodiment of the present invention. Referring to Figure 2, in this embodiment, the vehicle projection lens 10a is disposed between the magnifying side OS and the reducing side IS. The vehicle projection lens 10a has a lens barrel (not shown), in which lens L1, aperture 14, lens L2, lens L3 and lens L4 are arranged sequentially from the magnifying side OS to the reducing side IS. In addition, the image source 120 is located at the corresponding position on the reducing side IS. In this embodiment, the vehicle projection lens 10a is essentially composed of four lenses, and the refractive powers of lenses L1 to L4 on the optical axis 12 are positive, negative, positive and positive, respectively. Lens L1 is an aspherical plastic lens, and lenses L2, L3 and L4 are spherical glass lenses. Lens L2 and lens L3 form a cemented lens. The line connecting the two points P and Q of the mirror inflection point in Figure 2 is the maximum outer diameter of the first lens.

[0016] Furthermore, in the various embodiments of the present invention, the number of lenses, the shape of the lenses, and the optical characteristics can all be designed differently according to actual needs. The magnifying side OS of each embodiment of the present invention is located on the left side of each figure, while the image reduction side IS is located on the right side of each figure, and will not be described again.

[0017] The aperture 14 referred to in this invention is an aperture stop. Aperture 14 can be a standalone element, but the invention is not limited to this; aperture 14 can also be integrated into other optical elements. In this embodiment, aperture 14 achieves a similar effect by using a mechanism to block peripheral light while allowing light to pass through the central portion. This mechanism can be adjustable. Adjustability refers to adjustments in the position, shape, or transparency of the mechanism. Alternatively, aperture 14 can be coated with an opaque light-absorbing material on the lens surface, allowing light to pass through the central portion to limit the light path. A larger aperture 14 corresponds to a smaller aperture value (F-number) for the automotive projection lens 10a. According to the design of this embodiment, aperture 14 can be positioned between the lens closest to the magnifying side and the lens's reducing side.

[0018] A spherical lens is a lens in which both the front and rear surfaces are parts of a spherical surface, and the curvature of the spherical surface is fixed. The lens design parameters and shape of the automotive projection lens 10a are shown in Table 1. However, the information listed below is not intended to limit the invention. Anyone skilled in the art can make appropriate modifications to the parameters or settings after referring to this invention, but such modifications should still fall within the scope of this invention.

[0019] Table 1 lists the optical parameters of each lens in the optical system. An asterisk (*) in the surface number indicates that the surface is aspherical; conversely, if there is no asterisk, the surface is spherical. The units for radius of curvature and spacing / thickness in Table 1 are millimeters (mm).

[0020] Table 1 element surface Radius of curvature (mm) spacing (mm) Refractive index (Nd) Abbe number (Vd) Lens L1 (aspherical) S1* 43.79 7.32 1.4927 54.66 S2* 159.77 20.25 Aperture 14 S3 INF 9.07 Lens L2 (Crescent) S4 94.62 5.00 1.8467 23.79 Lens L3 (Biconvex) S5 25.81 14.00 1.7725 49.61 S6 -51.76 0.25 Lens L4 (Crescent) S7 19.29 13.00 1.7725 49.61 S8 16.71 6.90 Image source 120 S9

[0021] In Table 1, the radius of curvature (mm) refers to the radius of curvature of the corresponding surface, and the spacing (mm) refers to the straight-line distance between two adjacent surfaces on the optical axis 12. For example, the spacing between surfaces S1 is the distance between surfaces S1 and S2, and the spacing between surfaces S8 is the distance between surfaces S8 and S9. For the thickness, refractive index, and Abbe number of each lens and optical element in the column, please refer to the corresponding values ​​for spacing, refractive index, and Abbe number in the same column. Surfaces S1 and S2 are the two surfaces of lens L1. Surfaces S4 and S5 are the two surfaces of the second lens L2. For the parameter values ​​such as the radius of curvature and spacing of each surface, please refer to Table 1, which will not be repeated here.

[0022] The radius of curvature is the reciprocal of the curvature. When the radius of curvature is positive, the center of the sphere on the lens surface lies on the narrowing side of the lens. When the radius of curvature is negative, the center of the sphere on the lens surface lies on the magnifying side of the lens. The convexity and concavity of each lens can be seen in the table above.

[0023] The aperture value in this embodiment is represented by F / # (F-number), as shown in the table above. According to the design of this embodiment, the aperture value (F-number) of the automotive projection lens can be between 0.4 and 0.86, and the absolute value of the distortion of the automotive projection lens is less than 10%. In this embodiment, the aperture value (F-number) of the automotive projection lens 10a is 0.683. The maximum outer diameter of the aspherical plastic first lens L1 is approximately 51.4 mm. In some applications of this embodiment, a portion of the aspherical plastic first lens L1 will be cut off, referred to as a chamfer, but the maximum outer diameter is still calculated based on the outer diameter of the uncut portion. As shown in Figure 15, the line connecting points P and Q represents the maximum outer diameter of the chamfered first lens, and its value is the same as the maximum outer diameter of the uncut portion.

[0024] EFL is the effective focal length of the automotive projection lens 10a. In this embodiment, the effective focal length EFL of the automotive projection lens 10a is 30.9 mm, and |EFL / BFL|=4.48. BFL is the back focal length of the automotive projection lens. Wikipedia explains BFL as follows: "For thick lenses (lenses whose thickness cannot be ignored), or systems with several lenses or mirrors (such as camera lenses or telescopes), the focal length is usually expressed as the effective focal length (EFL) to distinguish it from commonly used parameters: ...back focal length (BFD) or back focal length (BFL) is the distance from the vertex of the last optical surface of the system to the rear focal point." That is, the spacing of S8 in Table 1 is 6.9 mm. When the automotive projection lens is used as an imaging lens, BFL is the distance from the vertex of the optical surface closest to the lens reduction side to the rear imaging surface. In this case, the object distance of the lens is set to infinity or the automotive projection lens is incident with zero-degree parallel light on the lens magnification side. The automotive projection lens of this invention can meet the condition that |EFL / BFL| > 3.8. When this condition is met, the image resolution can be avoided from decreasing too much under a large aperture. Preferably, |EFL / BFL| > 4.5, and more preferably, |EFL / BFL| > 5.05.

[0025] The field of view (FOV) refers to the light-receiving angle of the optical surface S1 closest to the magnifying side OS, which is the field of view measured along the horizontal diagonal. According to the design of this embodiment, the FOV can be greater than 14 degrees and less than 44 degrees, preferably greater than 16 degrees and less than 42 degrees, and more preferably greater than 18 degrees and less than 40 degrees. In this embodiment, the FOV of the automotive projection lens 10a is approximately 24 degrees.

[0026] According to the design of this embodiment, the total length (TTL) of the automotive projection lens is less than 90 mm, preferably less than 80 mm, which is the distance from the vertex of the optical surface (S1) closest to the magnification side of the lens to the rear imaging surface (image source 120). According to the design of this embodiment, the distance (S2) between the first lens and the second lens is between 15-40 mm, and the ratio of the distance between the first lens and the second lens to the total length (OAL) of the projection lens itself is between 0.22-0.56. According to this embodiment, the total length (OAL) of the projection lens itself is also the distance from the vertex of the optical surface (S1) to the vertex of the optical surface (S8) of the automotive projection lens. According to the design of this embodiment, the ratio of the maximum outer diameter of the first lens to the total length (OAL) of the projection lens itself is between 0.63-0.8. The ratio of the maximum outer diameter of the second lens to the total length (OAL) of the projection lens itself is between 0.51-0.79.

[0027] According to the design of this embodiment, the refractive index of the aspherical plastic first lens L1 can be between 1.47 and 1.6, preferably between 1.49 and 1.6, and even more preferably between 1.57 and 1.6. The material of the aspherical plastic lens can be, for example, PMMA or PC.

[0028] A spherical lens is a lens whose front and rear surfaces are both parts of a spherical surface, and the curvature of the spherical surface is fixed. An aspherical lens, on the other hand, has at least one surface whose radius of curvature varies with its central axis, and can be used to correct aberrations. In the following design examples of this invention, the aspherical polynomial can be expressed by the following formula: In the above formulas, Z is the offset (sag) along the optical axis, c is the reciprocal of the radius of the osculating sphere (i.e., the reciprocal of the radius of curvature near the optical axis), k is the conic coefficient, and r is the aspherical height, which is the height from the center of the lens to the edge of the lens. AG in Table 2 represents the coefficient values ​​of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial, respectively. However, the information listed below is not intended to limit the invention. Any person skilled in the art, upon referring to this invention, may make appropriate modifications to the parameters or settings, but such modifications should still fall within the scope of this invention.

[0029] Table 2 surface K A B C D E F G S1* -2.46 3.964E-05 -3.357E-07 2.008E-09 -6.854E-12 1.357E-14 -1.424E-17 6.022E-21 S2* 49.26 2.633E-05 -1.523E-07 6.340E-10 -8.220E-13 -1.681E-15 6.528E-18 -5.900E-21

[0030] Figures 11 and 12 are imaging optical simulation data diagrams of the automotive projection lens 10a in Figure 2. Figure 11 is a modulation transfer function (MTF) curve, with the horizontal axis representing the spatial frequency in cycles per millimeter and the vertical axis representing the modulus of the optical transfer function (OTF). Figure 12 is a distortion diagram of the three colors of light. Since the graphs shown in Figures 11 and 12 are within the required range, it can be verified that the automotive projection lens 10a of this embodiment can achieve good imaging results.

[0031] Figures 3-5 are schematic diagrams of the optical structures of the automotive projection lenses 10b-10d according to the second to fourth embodiments of the present invention. The main differences between the second and fourth embodiments and the first embodiment lie in the radius of curvature, spacing, refractive index, Abbe number, maximum outer diameter of the lens, aspherical coefficient, etc. In the second embodiment, the automotive projection lens 10b has a field of view (FOV) of approximately 24 degrees, an aperture value (F-number) of 0.68, an effective focal length (EFL) of 30.93 mm, and |EFL / BFL| = 4.5. The maximum outer diameter of the aspherical plastic first lens L1 is 51.4 mm. In the third embodiment, the automotive projection lens 10c has a field of view (FOV) of approximately 24 degrees, an aperture value (F-number) of 0.681, an effective focal length (EFL) of 30.9 mm, and |EFL / BFL| = 4.33. The maximum outer diameter of the aspherical plastic first lens L1 is 51.4 mm. In the fourth embodiment, the field of view (FOV) of the automotive projection lens 10d is approximately 24 degrees, the aperture value (F-number) is 0.691, the effective focal length (EFL) of the automotive projection lens 10d is 30.65 mm, and |EFL / BFL| = 4.58. The maximum outer diameter of the aspherical plastic first lens L1 is 51.4 mm. In the second to fourth embodiments, the design parameters of the lenses and their peripheral components of the automotive projection lenses 10b-10d are shown in Tables 3, 5, and 7, and the conic coefficient and aspherical coefficient of each aspherical surface are shown in Tables 4, 6, and 8.

[0032] Table 3 element surface Radius of curvature (mm) spacing (mm) Refractive index (Nd) Abbe number (Vd) Lens L1 (aspherical) S1* 46.74 7.23 1.4927 54.66 S2* 212.21 17.56 Aperture 14 S3 INF 11.81 Lens L2 (Crescent) S4 82.19 5.00 1.8467 23.79 Lens L3 (Biconvex) S5 26.03 14.00 1.7725 49.61 S6 -53.39 0.25 Lens L4 (Crescent) S7 20.15 13.00 1.7725 49.61 S8 17.37 6.87 Image source 120 S9

[0033] Table 4 surface K A B C D E F G S1* -3.119E+00 3.837E-05 -3.515E-07 2.085E-09 -6.781E-12 1.246E-14 -1.195E-17 4.592E-21 S2* 8.805E+01 2.968E-05 -2.575E-07 1.487E-09 -4.143E-12 5.134E-15 -5.937E-19 -2.786E-21

[0034] Table 5 element surface Radius of curvature (mm) spacing (mm) Refractive index (Nd) Abbe number (Vd) Lens L1 (aspherical) S1* 43.45 7.10 1.4927 54.66 S2* 155.28 19.07 Aperture 14 S3 INF 9.43 Lens L2 (Crescent) S4 126.70 5.00 1.8467 23.79 Lens L3 (Biconvex) S5 25.81 14.00 1.7725 49.61 S6 -51.92 0.25 Lens L4 (Crescent) S7 17.36 13.00 1.6968 55.53 S8 16.11 7.13 Image source 120 S9

[0035] Table 6 surface K A B C D E F G S1* -3.44 7.592E-05 -7.139E-07 4.123E-09 -1.393E-11 2.755E-14 -2.971E-17 1.333E-20 S2* 43.43 6.517E-05 -6.214E-07 3.465E-09 -1.096E-11 1.976E-14 -1.911E-17 7.530E-21

[0036] Table 7 element surface Radius of curvature (mm) spacing (mm) Refractive index (Nd) Abbe number (Vd) Lens L1 (aspherical) S1* 73.40 8.94 1.4927 54.66 S2* -290.97 33.84 Aperture 14 S3 INF 4.16 Lens L2 (Crescent) S4 65.88 1.00 1.8467 23.79 Lens L3 (Biconvex) S5 23.83 12.76 1.7725 49.61 S6 -54.78 0.25 Lens L4 (Crescent) S7 18.50 11.85 1.7725 49.61 S8 15.62 6.70 Image source 120 S9

[0037] Table 8 surface K A B C D E F G S1* -2.32 3.147E-05 -3.152E-07 2.031E-09 -7.260E-12 1.474E-14 -1.584E-17 7.077E-21 S2* -33.36 2.952E-05 -3.240E-07 2.659E-09 -1.188E-11 3.002E-14 -4.015E-17 2.246E-20

[0038] Figures 6-7 are schematic diagrams of the optical structures of the automotive projection lenses 10e-10f according to the fifth and sixth embodiments of the present invention. The main difference between the fifth and sixth embodiments and the first embodiment is the absence of a cemented lens. Other differences include the radius of curvature, spacing, refractive index, Abbe number, maximum outer diameter of the lens, aspherical coefficient, etc. In the fifth embodiment, the automotive projection lens 10e has a field of view (FOV) of approximately 24 degrees, an aperture value (F-number) of 0.688, an effective focal length (EFL) of 31.42 mm, and |EFL / BFL| = 4.71. The maximum outer diameter of the aspherical plastic first lens L1 is 50.68 mm. In the sixth embodiment, the automotive projection lens 10f has a field of view (FOV) of approximately 24 degrees, an aperture value (F-number) of 0.688, an effective focal length (EFL) of 31.33 mm, and |EFL / BFL| = 5.05. The maximum outer diameter of the aspherical plastic first lens L1 is 52.59 mm. In the fifth and sixth embodiments, the design parameters of the lens and its peripheral components of the automotive projection lens 10e-10f are shown in Tables 9 and 11, and the conic coefficient and aspheric coefficient of each aspherical surface are shown in Tables 10 and 12.

[0039] Table 9 element surface Radius of curvature (mm) spacing (mm) Refractive index (Nd) Abbe number (Vd) Lens L1 (aspherical) S1* 43.76 6.44 1.493 54.66 S2* 161.12 17.82 Aperture 14 S3 INF 3.65 Lens L2 (Crescent) S4 115.69 12.00 1.847 23.79 S5 34.34 0.63 Lens L3 (Biconvex) S6 36.49 13.91 1.729 54.67 S7 -42.71 3.75 Lens L4 (Crescent) S8 18.26 12.00 1.800 42.25 S9 15.19 6.67 Image source 120 S10

[0040] Table 10 surface K A B C D E F G S1* -9.15 4.063E-05 -3.354E-07 2.005E-09 -6.849E-12 1.358E-14 -1.425E-17 5.931E-21 S2* 49.30 1.818E-05 -1.394E-07 6.413E-10 -8.376E-13 -1.718E-15 6.500E-18 -5.836E-21

[0041] Table 11 element surface Radius of curvature (mm) spacing (mm) Refractive index (Nd) Abbe number (Vd) Lens L1 (aspherical) S1* 42.43 8.28 1.493 54.66 S2* 167.92 20.26 Aperture 14 S3 INF 14.46 Lens L2 (Crescent) S4 38.23 3.00 1.847 23.79 S5 23.08 0.77 Lens L3 (Biconvex) S6 24.67 11.26 1.729 54.67 S7 -62.09 0.25 Lens L4 (Crescent) S8 17.73 9.96 1.847 23.79 S9 12.67 6.20 Image source 120 S10

[0042] Table 12 surface K A B C D E F G S1* -9.66 4.407E-05 -3.356E-07 1.999E-09 -6.855E-12 1.358E-14 -1.421E-17 6.035E-21 S2* 52.81 1.847E-05 -1.338E-07 6.310E-10 -8.556E-13 -1.718E-15 6.553E-18 -5.636E-21

[0043] Figure 8 is a schematic diagram of the optical structure of the automotive projection lens 10g according to the seventh embodiment of the present invention. The main difference between this embodiment and the first embodiment is the absence of a cemented lens, and the aperture 14 being located between the second and third lenses. Other differences include the radius of curvature, spacing, refractive index, Abbe number, maximum outer diameter of the lens, aspherical coefficient, etc. In the seventh embodiment, the automotive projection lens 10g has a field of view (FOV) of approximately 24 degrees, an aperture value (F-number) of 0.67, an effective focal length (EFL) of 31.07 mm, and |EFL / BFL| = 5.01. The maximum outer diameter of the aspherical plastic first lens L1 is 49.02 mm. The design parameters of the lens and its peripheral components of the automotive projection lens 10g are shown in Table 13, and the conic coefficient and aspherical coefficient of each aspherical surface are shown in Table 14.

[0044] Table Thirteen element surface Radius of curvature (mm) spacing (mm) Refractive index (Nd) Abbe number (Vd) Lens L1 (aspherical) S1* 62.49 7.85 1.493 54.66 S2* -206.06 16.73 Lens L2 (Crescent) S3 -35.52 5.19 1.497 81.6128 S4 -30.34 0.25 Aperture 14 S5 INF 15.69 Lens L3 (Biconvex) S6 78.05 8.76 1.729 54.67 S7 -66.28 0.25 Lens L4 (Crescent) S8 19.03 12.00 1.729 54.67 S9 14.47 6.20 Image source 120 S10

[0045] Table 14 surface K A B C D E F G S1* -39.20 4.130E-05 -3.368E-07 2.003E-09 -6.844E-12 1.359E-14 -1.424E-17 5.927E-21 S2* 15.33 1.968E-05 -1.320E-07 6.447E-10 -8.382E-13 -1.709E-15 6.533E-18 -5.775E-21

[0046] Figures 9 and 10 are schematic diagrams of the optical structures of the automotive projection lenses 10h and 10i according to the eighth and ninth embodiments of the present invention, respectively. In this embodiment, the main difference from the first embodiment is that the maximum outer diameter of the third lens is greater than that of the first lens, along with its radius of curvature, spacing, refractive index, Abbe number, maximum outer diameter, aspherical coefficient, etc. In the eighth embodiment, the automotive projection lens 10h has a field of view (FOV) of approximately 24 degrees, an aperture value (F-number) of 0.597, an effective focal length (EFL) of 28.3 mm, and |EFL / BFL| = 4.84. The maximum outer diameter of the aspherical plastic first lens L1 is 52.6 mm. In the ninth embodiment, the field of view (FOV) of the automotive projection lens 10i is approximately 24 degrees, the aperture value (F-number) is 0.594, the effective focal length (EFL) of the automotive projection lens 10i is 28.3 mm, and |EFL / BFL| = 4.86. The maximum outer diameter of the aspherical plastic first lens L1 is 51.6 mm. The design parameters of the lenses and their peripheral components of the automotive projection lenses 10h and 10i are shown in Tables 15 and 17, and the conic coefficient and aspherical coefficient of each aspherical surface are shown in Tables 16 and 18.

[0047] Table 15 element surface Radius of curvature (mm) spacing (mm) Refractive index (Nd) Abbe number (Vd) Lens L1 (aspherical) S1* 34.84 7.430 1.4916 57.85 S2* 157.59 15.635 Aperture 14 S3 INF 2.144 Lens L2 (biconcave) S4 -241.48 3.293 1.8467 23.78 Lens L3 (Biconvex) S5 48.68 20,000 1.7130 53.87 S6 -43.08 0.100 Lens L4 (Crescent) S7 21.55 20,000 1.7725 49.60 S8 30.03 5.845 Image source 120 S9

[0048] Table 16 surface K A B C D E F G S1* -4.711E+01 8.513E-05 -4.963E-07 1.976E-09 -4.570E-12 5.652E-15 -3.031E-18 -4.711E+01 S2* -9.900E+01 1.700E-05 -6.026E-08 2.563E-10 -3.973E-13 4.214E-17 1.318E-19 -9.900E+01

[0049] Table 17 element surface Radius of curvature (mm) spacing (mm) Refractive index (Nd) Abbe number (Vd) Lens L1 (aspherical) S1* 33.48 8.52 1.4954 57.67 S2* 105.14 14.47 Aperture 14 S3 INF 1.69 Lens L2 (biconcave) S4 -580.10 4.40 1.8467 23.79 Lens L3 (Biconvex) S5 45.14 20.00 1.713 53.83 S6 -45.14 0.10 Lens L4 (Crescent) S7 21.73 20.00 1.7725 49.61 S8 30.31 5.82 Image source 120 S9

[0050] Table 18 surface K A B C D E F G S1* -3.996E+01 8.504E-05 -5.302E-07 2.146E-09 -5.015E-12 5.726E-15 -1.913E-18 -1.004E-21 S2* 1.544E+01 8.984E-06 -8.404E-08 4.774E-10 -1.496E-12 2.219E-15 -1.487E-18 2.541E-22

[0051] Figures 13 and 14 show the imaging optical simulation data of the automotive projection lens 10h in Figure 9. Figure 13 is a modulation transfer function (MTF) graph, with the horizontal axis representing the spatial frequency in cycles per millimeter and the vertical axis representing the modulus of the optical transfer function (OTF). Figure 14 shows the distortion of the three colors of light. Since the graphs shown in Figures 13 and 14 are within the required range, it can be verified that the automotive projection lens 10h of this embodiment can achieve good imaging results.

[0052] In embodiments of the present invention, by using an aspherical plastic lens for lens L1 and spherical glass lenses for lenses L2, L3, and L4, a lower manufacturing cost can be achieved while maintaining good image quality. Furthermore, by making the automotive projection lens essentially composed of four lenses, the goal of low manufacturing cost can also be achieved. Moreover, by selecting glass as the lens near the reduction side in embodiments of the present invention, a wider operating temperature range can be achieved. In summary, the automotive projection lens and automotive device of the present invention have at least one of the following advantages: the design of the embodiments of the present invention provides a lens design that meets traffic regulations in terms of illumination range, high resolution, low distortion, and miniaturization, and offers lower manufacturing costs and better image quality for application in automotive headlights.

[0053] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0054] 10;10a-10i: Automotive projection lens 12: Optical axis 14: Aperture 100: Vehicle lighting system 120: Image Source 130: Prism I: Image Beam L1-L4: Lenses S1-S10: Surface OS: Enlarged side IS: Shrinking side P, Q: Mirror inflection points

Claims

1. A vehicle projection lens, comprising: The projection lens comprises a cemented lens consisting of an aspherical first lens, a spherical second lens, and a spherical third lens arranged sequentially from the magnification side to the reduction side of the projection lens, and a spherical fourth lens; the aperture value (F-number) of the projection lens is less than or equal to 0.86; the field of view (FOV) of the projection lens is between 14 degrees and 44 degrees; the projection lens is essentially composed of the four lenses, and the refractive powers of the lenses are positive, negative, positive, and positive in sequence; and the automotive projection lens satisfies the condition |EFL / BFL| > 3.8, where EFL is the effective focal length of the automotive projection lens, and BFL is the distance from the vertex of the optical surface closest to the reduction side of the projection lens to the imaging plane.

2. A vehicle projection lens, comprising, in sequence along one direction: The first lens is an aspherical lens; A second lens with negative diopter; a third lens with diopter. A fourth lens, having positive diopter, is the lens closest to the lens reduction side among the four lenses; the projection lens satisfies the following conditions: the aperture value (F-number) of the projection lens is less than or equal to 0.86; the field of view (FOV) of the projection lens is between 14 degrees and 44 degrees; the projection lens is substantially composed of the four lenses; the first lens is the lens with the largest outer diameter among the four lenses; and |EFL / BFL| > 3.8, where EFL is the effective focal length of the automotive projection lens, and BFL is the distance from the vertex of the optical surface of the automotive projection lens closest to the lens reduction side to the imaging plane.

3. The vehicle projection lens as described in any one of claims 1-2, wherein the projection lens satisfies one of the following conditions: (1) an aperture is provided between the magnifying side of the projection lens and a third lens; (2) a prism or a mirror is provided on the reducing side of the projection lens; (3) the aperture value (F-number) is between 0.4 and 0.

86.

4. The vehicle projection lens as described in any one of claims 1-2, wherein the projection lens satisfies one of the following conditions: (1) the radius of curvature of the surface of the first lens facing the magnification side of the projection lens is positive, and (2) the total length (TTL) of the projection lens is less than 90 mm.

5. The automotive projection lens as described in any one of claims 1-2, wherein the projection lens satisfies one of the following conditions in a direction from the magnification side to the reduction side of the projection lens: (1) in sequence from that direction, it is an aspherical, crescent, biconvex, crescent lens; (2) in sequence from that direction, it is an aspherical, biconcave, biconvex, crescent lens.

6. The vehicle projection lens as described in any of claims 2, wherein the refractive power of the lens in the projection lens in a direction from the magnification side to the reduction side of the projection lens is positive, negative, positive, positive in sequence.

7. The vehicle projection lens as described in any one of claims 1-2, wherein the projection lens satisfies one of the following conditions: (1) the distance between the first lens and the second lens is between 15 and 40 mm, and (2) the ratio of the distance between the first lens and the second lens to the total length (OAL) of the projection lens itself is between 0.22 and 0.

56.

8. A vehicle projection lens as described in any one of claims 1-2, wherein the projection lens satisfies one of the following conditions: (1) the ratio of the maximum outer diameter of the first lens to the total length (OAL) of the projection lens itself is between 0.63 and 0.8, and (2) the ratio of the maximum outer diameter of the second lens to the total length (OAL) of the projection lens itself is between 0.51 and 0.

79.

9. A vehicle projection lens as described in any one of claims 1-2, wherein the projection lens satisfies one of the following conditions: (1) the aspherical lens is made of plastic, (2) the projection lens is a glass-plastic hybrid structure, and (3) the projection lens includes a cemented lens.

10. A vehicle lighting device, comprising: a light source consisting of an LED array; and a projection lens substantially composed of four lenses, disposed downstream of the light source, the projection lens comprising, in sequence: The first lens is an aspherical shape; A second lens with negative refractive power; A third lens, with diopter; And a fourth lens, having positive diopter, and being the lens closest to the light source among the four lenses; a headlight housing, located downstream of the optical path of the projection lens; wherein the aperture value (F-number) of the projection lens is less than or equal to 0.86; the projection lens satisfies the condition |EFL / BFL| > 3.8, where EFL is the effective focal length of the projection lens, BFL is the distance from the vertex of the optical surface closest to the narrowing side of the projection lens to the imaging plane; and the field of view (FOV) of the projection lens is between 14 degrees and 44 degrees.

11. The vehicle lighting device as claimed in claim 10, wherein the vehicle lighting device satisfies one of the following conditions: (1) the light-emitting diode array is a micro LED array light source, and (2) in a direction from the magnification side of the projection lens to the reduction side of the projection lens, the refractive power of the lens in that direction is positive, negative, positive, positive in sequence.

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