An optical lens with high efficiency and high image quality resolution

Abstract

The present application relates to a kind of optical lens of high efficiency and high image quality resolution, comprising: first lens, second lens, third lens, fourth lens and image plane are sequentially arranged;Wherein first lens, third lens and fourth lens have positive refractive power, second lens has negative refractive power;The Abbe coefficient of the second lens is lower than the other three lenses;And the first surface and the second surface of second lens are curved to the side away from image plane;Aperture stop, it is arranged between second lens or second lens and object plane;Vignetting diaphragm, it is arranged between third lens or fourth lens or third lens and fourth lens.This embodiment, aperture stop can limit system light aperture, illumination efficiency is high;Vignetting diaphragm arranged between third lens or fourth lens or third lens and fourth lens improves image quality by limiting large field of view light aperture;Again, 4 lenses are combined to correct, optimize the optical aberration of system.

Description

Technical Field

[0001] This invention relates to the field of optical design, and in particular to a high-efficiency optical lens with high image resolution. Background Technology

[0002] Traditional vehicle lighting devices can provide good illumination at night, but when oncoming or same-direction vehicles appear in front of the driver, they may cause glare to the other driver, creating a safety hazard.

[0003] Pixelated lighting fixtures can solve the above problems, primarily by identifying the position of vehicles ahead and masking their location to avoid glare, while ensuring adequate illumination in areas outside the vehicles. The higher the resolution of the pixelated lighting device, the more accurately it can mask the area in front of the vehicle, resulting in a larger illumination range beyond the masked area. Figure 1 It can be seen that, Figure 1 When the pixels segmented on the left are large, the obstacles are not illuminated. Figure 1 When the pixel size is smaller on the right side, obstacles can be illuminated, making driving safer. Therefore, higher pixel resolution means that the illuminated area can avoid more potential risks, providing safer driving at night.

[0004] High-resolution pixelated lighting systems differ from traditional automotive lighting systems. They not only need to provide high illumination efficiency but also need to maintain clear image resolution. Therefore, a lens assembly is required to optimize and reduce various optical aberrations, such as distortion, spherical aberration, and field curvature, to obtain better image quality. Generally, smaller aperture lens assemblies can effectively optimize the optical aberrations of the system, but they cannot provide high illumination efficiency. Larger aperture lens assemblies have high illumination efficiency, but they usually require five or more lenses to correct aberrations, resulting in higher costs. Summary of the Invention

[0005] Therefore, it is necessary to provide an optical lens that is both highly efficient and has high image resolution, addressing at least some of the aforementioned problems.

[0006] A high-efficiency optical lens with high image resolution includes:

[0007] The first lens, second lens, third lens, fourth lens and image plane are arranged in sequence. The side of each lens away from the image plane is the first surface and the side closer to the image plane is the second surface.

[0008] The first, third, and fourth lenses have positive optical power, while the second lens has negative optical power.

[0009] The Abbe coefficient of the second lens is lower than that of the other three lenses;

[0010] Furthermore, both the first and second surfaces of the second lens are curved away from the image plane;

[0011] An aperture stop is located at the position between the first lens, the second lens, or the first lens and the second lens;

[0012] A vignetting stop is located at the position between the third lens, the fourth lens, or the third lens and the fourth lens.

[0013] The central field of view of the optical lens has an output aperture Z1 on the first surface of the first lens that is 70% larger than the light transmission aperture L1 of that surface, and the edge field of view has an output aperture B1 on the first surface of the first lens that is 50% larger than the light transmission aperture L1 of that surface.

[0014] The ratio of the light-transmitting aperture L4 of the second surface of the fourth lens facing the image plane to the back intercept J1 of the lens group is greater than 2, and the light collection half angle α is greater than 35°.

[0015] In some embodiments, the aperture stop is disposed on the surface of the first lens or the second lens.

[0016] In some embodiments, the aperture stop is disposed on the side surface of the first lens near the image plane.

[0017] In some embodiments, the refractive index of the fourth lens is greater than that of the third lens.

[0018] In some embodiments, the surfaces of the first lens and the second lens are spherical or aspherical, and the surfaces of the third lens and the fourth lens are spherical.

[0019] In some embodiments, the distance L from the first surface of the first lens away from the image plane to the image plane does not exceed 80 mm.

[0020] In some embodiments, the field of view (FOV) of the lens group is greater than 10.5°, and the aperture of the first lens is in the range of 40 to 60 mm.

[0021] The aforementioned high-efficiency and high-resolution optical lenses have at least the following beneficial technical effects:

[0022] This invention provides a four-element, low-cost lens group design that achieves both high optical efficiency and good image quality with a large aperture.

[0023] In this embodiment, the aperture stop can limit the light transmission diameter of the system. The light output diameter Z1 of the center field of view of the lens group on the first surface of the first lens is more than 70% greater than the light transmission diameter L1 of the surface, and the light output diameter B1 of the edge field of view on the first surface of the first lens is more than 50% greater than the light transmission diameter L1 of the surface, resulting in high illumination efficiency.

[0024] The ratio of the light-transmitting aperture L4 of the second surface of the fourth lens facing the image plane to the back intercept J1 of the lens group is greater than 2, which allows the lens group to have a large light-collecting angle (half angle α greater than 35°) for the light source located at the image plane 50, thereby obtaining good illumination efficiency.

[0025] Because the requirements for nighttime lighting in the middle of the road are higher than those on the sides, the illumination requirements for the central field of view of the lens group are higher, while the illumination brightness of the peripheral field of view can be reduced. Therefore, the vignetting stop provided in this application, located between the third or fourth lens or between the third and fourth lenses, improves image quality by limiting the aperture of the peripheral field of view. Combined with the four lenses, optical aberrations of the system, such as distortion, spherical aberration, and field curvature, are corrected and optimized to obtain better image quality.

[0026] The pixelated lighting device of this application has high resolution, which can more accurately block the area in front of the vehicle, resulting in a larger lighting range outside the blocked area. When the number of pixels is small, obstacles can be illuminated, making driving safer. Therefore, the high pixel resolution allows the lighting area to avoid more potential risks and provides safer driving at night. Attached Figure Description

[0027] Figure 1 This is a schematic diagram comparing the degree of pixel segmentation with the degree to which obstacles are illuminated;

[0028] Figure 2 A schematic diagram of a high-efficiency optical lens with high image resolution provided in an embodiment of the present invention;

[0029] Figure 3 for Figure 2 A schematic diagram showing the aperture stop, vignetting stop, and the total length L of a high-efficiency, high-resolution optical lens.

[0030] Figure 4 This is a schematic diagram of the light-passing aperture L1 of the first surface of the first lens and the light-exiting aperture Z1 of the central field of view.

[0031] Figure 5 This is a schematic diagram of the light-passing aperture L1 and the light-exiting aperture B1 of the edge field of view of the first surface of the first lens.

[0032] Figure 6 A schematic diagram showing the light-transmitting aperture L4 of the second surface of the fourth lens and the back intercept J1 of the lens group;

[0033] Figure 7 This is a schematic diagram of the angle α of the light rays collected by the central field of view in this embodiment;

[0034] Figure 8 This is a schematic diagram of the MTF (0-12.5 lp / mm) in this embodiment;

[0035] Figure 9This is a schematic diagram of the MTF (0-8 lp / mm) of this embodiment;

[0036] Figure 10 This is the distortion diagram for this embodiment;

[0037] In the picture,

[0038] 10. First lens;

[0039] 20. Second lens;

[0040] 30. The third lens;

[0041] 40. The fourth lens;

[0042] 50. Like a face;

[0043] 60. Aperture stop;

[0044] 70. Gradually becoming hazy. Detailed Implementation

[0045] The invention will now be further described with reference to the accompanying drawings.

[0046] To facilitate understanding of the present invention, various embodiments as defined by the claims will be described more fully below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings, which include various specific details to aid this understanding, but these details should be considered merely exemplary. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Accordingly, those skilled in the art will recognize that variations and modifications can be made to the various embodiments described herein without departing from the scope of the invention as defined by the appended claims. Furthermore, descriptions of well-known functions and constructions may be omitted for clarity and brevity.

[0047] It will be apparent to those skilled in the art that the following description of various embodiments of the invention is provided for illustrative purposes only and is not intended to limit the invention as defined by the appended claims.

[0048] Throughout the specification and claims of this application, the words “comprising” and “including,” as well as variations thereof, such as “comprising of” and “including,” mean “including but not limited to,” and are not intended to exclude other components, elements, or steps. Features, elements, or characteristics described in connection with a particular aspect, embodiment, or example of the invention are to be understood as applicable to any other aspect, embodiment, or example described herein, unless incompatible therewith.

[0049] It should be understood that the singular forms “a,” “an,” and “the” include plural references unless the context explicitly specifies otherwise. The expressions “comprising” and / or “may comprise” as used in this invention are intended to indicate the presence of a corresponding function, operation, or element, and are not intended to limit the presence of one or more functions, operations, and / or elements. Furthermore, in this invention, the terms “comprising” and / or “having” are intended to indicate the presence of the features, quantities, operations, elements, and components disclosed in the applications, or combinations thereof. Therefore, the terms “comprising” and / or “having” should be understood as implying the additional possibility of one or more other features, quantities, operations, elements, and components, or combinations thereof.

[0050] In this invention, the expression "or" includes any or all combinations of the words listed together. For example, "A or B" can include either A or B, or it can include both A and B.

[0051] It should be understood that when an element is said to be "fixed to" another element, it can be directly on the other element or there may be an intervening element; when an element is said to be "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or there may be an intervening element at the same time.

[0052] The terms "up," "down," "left," and "right" mentioned in the text are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms (such as those defined in common dictionaries) should be interpreted as having the meaning consistent with the relevant field and the context of this specification, and should not be interpreted in an idealized or overly formal sense unless expressly defined herein. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0054] like Figures 2-3 As shown, in one embodiment of the present invention, a high-efficiency optical lens with high image resolution is provided, comprising:

[0055] The first lens 10, the second lens 20, the third lens 30, the fourth lens 40 and the image plane 50 are arranged in sequence. The side of each lens away from the image plane 50 is the first surface, and the side closer to the image plane 50 is the second surface.

[0056] The first lens 10, the third lens 30, and the fourth lens 40 have positive optical power, while the second lens 20 has negative optical power. Optical power φ characterizes the refractive power of the optical system for an incident parallel beam of light. The larger the value of φ, the more pronounced the refraction of the parallel beam; when φ > 0, the refraction is converging; when φ < 0, the refraction is diverging. When φ = 0, it corresponds to plane refraction; in this case, the axial parallel beam remains axially parallel after refraction, and no refraction occurs.

[0057] The Abbe coefficient of the second lens 20 is lower than that of the other three lenses, and both the first and second surfaces of the second lens 20 are curved toward the side away from the image plane 50.

[0058] The aperture stop 60 is located between the first lens 10, the second lens 20, or the first lens 10 and the second lens 20;

[0059] The vignetting stop 70 is located at the position between the third lens 30, the fourth lens 40, or the third lens 30 and the fourth lens 40.

[0060] The central field of view of the optical lens has an output aperture Z1 on the first surface of the first lens that is 70% larger than the light transmission aperture L1 of that surface, and the edge field of view has an output aperture B1 on the first surface of the first lens that is 50% larger than the light transmission aperture L1 of that surface.

[0061] The ratio of the light-transmitting aperture L4 of the second surface of the fourth lens facing the image plane to the back cutoff J1 of the lens group is greater than 2.

[0062] The following table shows a set of lens group surface shapes, positions, and material parameters for an embodiment of the present invention:

[0063]

[0064] The expression for an aspherical lens is as follows:

[0065]

[0066] Where z is the sag at position r on the aspherical surface, c is the paraxial curvature of the aspherical surface, c = 1 / r, r is the radius of curvature, k is the conic coefficient, and A to J are coefficients of higher-order terms.

[0067] The following table lists the parameters of the aspherical surface:

[0068]

[0069] In this embodiment, the aperture stop 60 of the system coincides with the second surface of the first lens 10, and the vignetting stop 70 coincides with the first surface of the fourth lens 40. The total length of the lens group in this embodiment is 62.9 mm.

[0070] The lens assembly of this invention has a high energy harvesting efficiency for each field of view. In specific implementation example one, the angle (half-angle) of the light collected in the center field of view is greater than 43 degrees (as shown in the attached figure). Figure 7 Therefore, this lens group has high illumination efficiency. If a light source with a emission angle of 2π is placed on the image plane 50, its energy utilization rate can also be greater than 40%.

[0071] The lens assembly described in this invention has excellent image quality, for reference. Figure 8 In the specific implementation case, the MTF is at 12.5 lp / mm, the center field of view is greater than 0.85 (corresponding to the uppermost 0-deeg curve in the implementation case), and the edge field of view (corresponding to the lowermost 12-deeg curve in the implementation case) is greater than 0.55; (Reference) Figure 9 At 8 lp / mm, the center field of view is greater than 0.95 and the edge field of view is greater than 0.75.

[0072] MTF is a scientific method for evaluating lens resolution; the closer it is to 1, the better the image quality. Figure 8 The curve corresponding to the central field of view (0deg) is closer to 1 than the curve corresponding to the peripheral field of view (12deg), meaning the central field of view has higher resolution. lp / mm refers to the number of light and dark line pairs that can be clearly seen within 1mm; a higher number of line pairs indicates higher resolution.

[0073] refer to Figure 10 The distortion of the lens group described in this invention is no more than 5%.

[0074] This invention provides a four-element, low-cost lens group design that achieves both high optical efficiency and good image quality with a large aperture.

[0075] In this embodiment, the aperture stop 60 can limit the light transmission aperture of the system, as referenced. Figure 4 , Figure 5 The light-emitting aperture Z1 of the center field of view of the lens group is more than 70% greater than the light-transmitting aperture L1 of the first surface of the first lens 10, and the light-emitting aperture B1 of the edge field of view of the first surface of the first lens 10 is more than 50% greater than the light-transmitting aperture L1 of the first surface, resulting in high illumination efficiency.

[0076] refer to Figure 6 The ratio of the aperture L4 (aperture of the light-transmitting area) of the second surface of the fourth lens 40 near the image plane 50 to the back cutoff J1 (distance between the center of the second surface of the fourth lens 40 near the image plane 50 and the image plane 50) is greater than 2, which allows the lens group to have a larger light collection angle for the light source located at the image plane 50 (as shown in the figure, half angle α is 43°), thereby obtaining good illumination efficiency.

[0077] Because the requirements for nighttime lighting in the middle of the road are higher than those on the sides, the illumination requirements for the center field of view of the lens group are higher, while the illumination brightness of the edge field of view can be reduced. Therefore, the vignetting stop 70 provided in this application, located between the third lens 30, the fourth lens 40, or the third lens 30 and the fourth lens 40, improves image quality by limiting the light transmission aperture of the edge field of view. That is, the setting of the vignetting stop 70 in this application improves image quality by sacrificing the illumination of the edge field of view. Combined with the four lenses, optical aberrations of the system, such as distortion, spherical aberration, and field curvature, are corrected and optimized to obtain better image quality.

[0078] This application's pixelated lighting device has high resolution, enabling more precise masking of the area in front of vehicles, resulting in a larger illumination range outside the masked area. Figure 1 As can be seen, when the number of pixels is small, obstacles can be illuminated, making driving safer. Therefore, with high pixel resolution, the illuminated area can avoid more potential risks, providing safer driving at night.

[0079] In some embodiments, the aperture stop 60 is disposed on the surfaces of the first lens 10 and the second lens 20. The aperture stop 60 is used to limit the light-transmitting aperture of the system. If it were disposed between the first lens 10 and the second lens 20 or between the first lens 10 and the object surface, additional components for light blocking would be required. However, by disposing the aperture stop 60 on the lens surface, the area outside the lens aperture is not light-transmitting. Therefore, the lens itself determines the light-transmitting aperture, eliminating the need for additional components and significantly reducing costs.

[0080] refer to Figure 3 In some embodiments, the aperture stop 60 is disposed on the surface of the first lens 10 near the image plane 50. When the lens group is used in a vehicle lighting device, the image plane 50 is the position of the light source. The light emitted by the light source passes through the fourth lens 40, the third lens 30, and the second lens 20 in sequence, and finally exits from the first lens 10. By disposing of the aperture stop 60 on the surface of the first lens 10 near the image plane 50, the light aperture of the first lens 10 can be made as large as possible for each field of view, that is, more light is emitted, thereby obtaining higher lighting efficiency.

[0081] Referring to the figure, in some embodiments, the refractive index of the fourth lens 40 is greater than that of the third lens 30. When the lens group is used for vehicle lighting, the light source is set at the image plane 50 of the lens group, and the fourth lens 40 is closer to the light source. The light emitted by the light source passes through the fourth lens 40 preferentially. The higher refractive index has a stronger deflection energy of the light, and more energy emitted by the light source can be collected into the lens group, making the lighting efficiency of the lens group higher. Therefore, it is preferable to use a material with a higher refractive index than the third lens 30 for the fourth lens 40.

[0082] In some embodiments, the surfaces of the first lens 10 and the second lens 20 can be spherical or aspherical, and the surfaces of the third lens 30 and the fourth lens 40 are spherical. Since the third lens and the fourth lens are made of glass, and the processing cost of a spherical glass surface is much lower than that of an aspherical surface, the use of a spherical design can reduce costs. Therefore, the lens group of the present invention can have better cost control.

[0083] In some embodiments, the first lens, second lens, third lens, and fourth lens are made of different materials with different refractive indices and Abbe coefficients. The interplay of lenses with different properties minimizes chromatic aberration, and practical experiments have shown that the different Abbe coefficients of the four lenses better balance the chromatic aberration of the lens group.

[0084] In some embodiments, anti-reflective coatings may be provided on some or all of the surfaces of the first lens 10, the second lens 20, the third lens 30, and the fourth lens 40. The anti-reflective coatings reduce energy loss caused by Fresnel reflection when light passes through the lens surfaces, thereby improving the illumination efficiency of the system.

[0085] refer to Figure 3 In some embodiments, the distance L from the first surface of the first lens 10 away from the image plane 50 to the image plane 50 is no more than 80 mm, preferably less than 65 mm, which has a smaller depth compared to conventional lighting optical systems and is more advantageous for placement in luminaires with limited space.

[0086] In some embodiments, the half-field of view (FOV) of the lens assembly is greater than 10.5°. The lens assembly of this invention has a wide FOV; in the embodiment, the half-FOV is 12 degrees, which results in a larger illumination range and improves driving safety. The lighting device equipped with this lens assembly can provide more illumination to one side of the curve when the vehicle enters a curve, improving driving safety. The larger FOV provided by the lens assembly means a greater range of illumination provided towards the curve.

[0087] In some embodiments, the aperture of the first lens 10 is in the range of 40 to 60 mm. A aperture smaller than 40 mm cannot achieve high system illumination efficiency, while an aperture larger than 60 mm affects the lens group from achieving good image resolution.

[0088] A light-emitting component includes a light source and a high-efficiency optical lens with high image resolution as described above, wherein the light source is disposed on the image plane 50.

[0089] A vehicle includes a vehicle body and the light-emitting component, wherein the light-emitting component is disposed on the vehicle body.

[0090] In the above description, although expressions such as "first" and "second" may be used to describe various elements of the invention, they are not intended to limit the corresponding elements. For example, the above expressions are not intended to limit the order or importance of corresponding elements. The above expressions are used to distinguish one component from another.

[0091] The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. Singular expressions include plural expressions unless there are significant differences in context or approach between them.

[0092] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the scope of protection of the present invention, which is determined by the appended claims.

[0093] Those skilled in the art will understand that the technical features of the above embodiments can be omitted, added, or combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, and simple transformations that those skilled in the art can conceive of, as well as structural transformations that adapt to and functionally modify the prior art, should be considered within the scope of this specification.

[0094] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that although the present invention has been shown and described with reference to various embodiments, those skilled in the art can make various modifications and improvements in form and detail without departing from the concept of the present invention, and without departing from the scope of the invention as defined by the appended claims. All such modifications and improvements fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A high-efficiency optical lens with high image resolution, characterized in that, include: The first lens, second lens, third lens, fourth lens and image plane are arranged in sequence. The side of each lens away from the image plane is the first surface and the side closer to the image plane is the second surface. The first, third, and fourth lenses have positive optical power, while the second lens has negative optical power. The Abbe coefficient of the second lens is lower than that of the other three lenses; Furthermore, the first surface of the second lens protrudes to the side away from the image plane to form a convex surface, and the second surface bends to the side away from the image plane to form a concave surface. An aperture stop is located at the position between the first lens, the second lens, or the first lens and the second lens; A vignetting stop is located at the position between the third lens, the fourth lens, or the third lens and the fourth lens. The central field of view of the optical lens has an output aperture Z1 on the first surface of the first lens that is 70% larger than the light transmission aperture L1 of that surface, and the edge field of view has an output aperture B1 on the first surface of the first lens that is 50% larger than the light transmission aperture L1 of that surface. The ratio of the light-transmitting aperture L4 of the second surface of the fourth lens facing the image plane to the back intercept J1 of the lens group is greater than 2, and the light collection half angle α is greater than 35°. The surface shape and position parameters of each lens in the optical lens: The expression for an aspherical lens is as follows: Where z is the elevation at position r on the aspherical surface, c is the paraxial curvature of the aspherical surface, c = 1 / r, r is the radius of curvature, k is the conic coefficient, and A to J are coefficients of higher-order terms. The following table lists the parameters of the aspherical surface: 。 2. The high-efficiency optical lens with high image resolution according to claim 1, characterized in that, The aperture stop is disposed on the surface of the first lens or the second lens.

3. The high-efficiency optical lens with high image resolution according to claim 1, characterized in that, The aperture stop is located on the surface of the first lens near the image plane.

4. The high-efficiency optical lens with high image resolution according to claim 1, characterized in that, The refractive index of the fourth lens is greater than that of the third lens.

5. The high-efficiency optical lens with high image resolution according to claim 1, characterized in that, The field of view (FOV) of the lens assembly is greater than 10.5°, and the aperture of the first lens is in the range of 40 to 60 mm.

6. A light-emitting component, characterized in that, It includes a light source and a high-efficiency optical lens with high image resolution as described in any one of claims 1-5, wherein the light source is disposed on the image plane.

7. A vehicle, characterized in that, It includes a vehicle body and a light-emitting component as described in claim 6, wherein the light-emitting component is disposed on the vehicle body.

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