A small aperture optical lens capable of achieving high resolution

Abstract

The application discloses a small-caliber optical lens capable of realizing high resolution, comprising three lenses, the three lenses being sequentially the first lens, the second lens and the third lens from the light source side to the outside; the first lens and the third lens have positive refractive power, and the second lens has negative refractive power; the light entrance surface of the first lens is a plane, the light exit surface of the first lens and the light exit surface of the third lens are both curved surfaces facing the outside, the light entrance surface and the light exit surface of the second lens and the light entrance surface of the third lens are all curved surfaces facing the light source; and the diameters of the first lens, the second lens and the third lens are all less than 30 mm. The small-caliber optical lens capable of realizing high resolution adopts a three-piece lens structure, and through specific combination of the three lenses, higher optical performance is obtained while the design requirement of miniaturization of customers is met, so that the trend and fashion of future miniaturization of subsequent automobile headlamps are met.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile headlamp lighting, and in particular to a small-aperture optical lens capable of achieving high resolution. Background Art

[0002] With the rapid development of automotive front lighting technology, high-pixel and ultra-high-pixel (over 1,000 or 10,000 pixels) technologies are gradually entering the automotive lighting market. Current automotive lighting technologies are still primarily in the low- to medium-pixel range, and eliminating chromatic aberration in imaging remains a significant technical challenge. Furthermore, the large light output aperture and long optical focal length create a significant conflict with the increasingly compact design of automotive lights. Summary of the Invention

[0003] In order to solve the technical problem in the prior art that car lights can only achieve medium and low pixel lighting and have a large light output aperture, which is in great conflict with the increasingly compact car light shape, the present invention provides a small-aperture optical lens that can achieve high resolution to solve the above problem.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a small-aperture optical lens capable of achieving high resolution, comprising three lenses, which are, from the light source side to the outside, a first lens, a second lens, and a third lens; the first lens and the third lens have positive refractive power, and the second lens has a negative refractive power; the light incident surface of the first lens is a plane, the light exit surface of the first lens and the light exit surface of the third lens are both curved surfaces facing outward, the light incident surface and light exit surface of the second lens, and the light incident surface of the third lens are all curved surfaces facing the light source; and the diameters of the first lens, the second lens, and the third lens are all less than 30 mm.

[0005] Furthermore, the combined focal length of the three lenses, f(EFL)=(15-21) mm, and the maximum field angle generated by the optical lens is greater than 35°.

[0006] Furthermore, the diameter of the first lens is 20 mm, the diameter of the second lens is 28 mm, and the diameter of the third lens is 30 mm.

[0007] Furthermore, the focal length of the second lens is f2, then -15mm <f2<-10mm。

[0008] Furthermore, at least one of the three lenses is a glass aspheric lens with an anti-reflection film.

[0009] Furthermore, the Abbe number Vd of the first lens and the third lens is ≥56; the Abbe number Vd of the second lens is ≤30.

[0010] Furthermore, the light source corresponding to the optical lens is a rectangular surface light source, and the maximum diagonal size IH of the rectangular surface light source is ≥10 mm.

[0011] Furthermore, the total length L of the optical lens along the optical axis is less than 50 mm.

[0012] Furthermore, the focal length of the third lens is f3, and thus 1.4<f3 / f(EFL)<1.9.

[0013] The beneficial effects of the present invention are:

[0014] (1) The small-aperture optical lens capable of achieving high resolution described in the present invention adopts a three-piece lens structure. Through the specific combination of the three lenses, it achieves higher optical performance while also meeting the customer's miniaturization design requirements, thereby meeting the future trend and fashion of miniaturization of subsequent automobile headlights.

[0015] (2) The present invention achieves better sensitivity and performance through a reasonable diopter distribution method. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and examples.

[0017] Figure 1 It is a structural diagram of a specific embodiment of the small-aperture optical lens capable of achieving high resolution according to the present invention.

[0018] Figure 2 The axial chromatic aberration diagram corresponding to three characteristic light rays with wavelengths of 486nm, 588nm, and 656nm passing through the optical lens described in Example 1;

[0019] Figure 3 The vertical axis chromatic aberration diagram corresponding to three characteristic light rays with wavelengths of 486nm, 588nm, and 656nm passing through the optical lens described in Example 1;

[0020] Figure 4 The relative illumination diagram corresponding to three characteristic light rays with wavelengths of 486 nm, 588 nm, and 656 nm passing through the optical lens described in Example 1;

[0021] Figure 5 This is a structural diagram corresponding to three characteristic light rays with wavelengths of 486nm, 588nm, and 656nm passing through the optical lens described in Example 2;

[0022] Figure 6 This is a graph of axial chromatic aberration corresponding to three characteristic light rays with wavelengths of 486nm, 588nm, and 656nm passing through the optical lens described in Example 2;

[0023] Figure 7The vertical axis chromatic aberration diagram corresponding to three characteristic light rays with wavelengths of 486nm, 588nm, and 656nm passing through the optical lens described in Example 2;

[0024] Figure 8 This is a relative illumination diagram corresponding to three characteristic light rays with wavelengths of 486nm, 588nm, and 656nm passing through the optical lens described in Example 2.

[0025] In the figure, 1 is the first lens, 2 is the second lens, 3 is the third lens, and 4 is the light source. DETAILED DESCRIPTION

[0026] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0027] A small-aperture optical lens capable of achieving high resolution includes three lenses, which are arranged in order from the side of a light source 4 to the outside: a first lens 1, a second lens 2, and a third lens 3. The first lens 1 and the third lens 3 have positive refractive power, while the second lens 2 has negative refractive power. A reasonable distribution of refractive powers can improve the sensitivity and performance of the optical lens. The light entrance surface of the first lens 1 is a plane, while the light exit surface of the first lens 1 and the light exit surface of the third lens 3 are both curved surfaces facing outward, and the light entrance and exit surfaces of the second lens 2 and the light entrance surface of the third lens 3 are all curved surfaces facing the light source 4. That is, the first lens 1 is a plano-convex lens, and the second lens 2 and the third lens 3 are both hyperbolic lenses. The diameters of the first lens 1, the second lens 2, and the third lens 3 are all less than 30 mm. This allows for a miniaturized design of the optical lens. Testing has shown that the combination of the three lenses can meet higher optical requirements.

[0028] In a preferred embodiment, the combined focal length f(EFL) of the three lenses is 15 mm to 21 mm, and the optical lens produces a field of view greater than 35°. The field of view is related to the focal length and size of the optical lens. Proper design of the field of view can ensure that no blind spots are created while also ensuring the illuminated area is as clear as possible. Compared to conventional optical lenses, this embodiment allows for a shorter focal length while maintaining consistent optical performance.

[0029] The focal length of the second lens 2 is f2. To achieve a better focusing effect, -15mm <f2<-10mm。

[0030] Since the third lens 3 has the beam shaping effect, the focal length of the third lens 3 can be further optimized, and the focal length of the third lens 3 is f3, and the ratio of the focal length of the third lens 3 to the effective focal length of the optical lens satisfies 1.4 < f3 / f(EFL) < 1.9.

[0031] When the optical lens corresponds to the rectangular surface light source 4, the maximum diagonal size IH of the rectangular surface light source is greater than or equal to 10 mm, the relative illumination value under this light source 4 condition is relatively large, and as preferred, the total length L of the optical lens in the optical axis direction is less than 50 mm. Thus, under the premise of minimizing the size of the optical lens, better pixel quality is ensured. Let the central thickness of the first lens 1 be d1, the central thickness of the second lens 2 be d2, and the central thickness of the third lens 3 be d3; the air gap between the surface of the light source 4 and the first lens 1 is d01, the air gap between the first lens 1 and the second lens 2 is d12, and the air gap between the second lens 2 and the third lens 3 is d23, then L = d1+d2+d3+d01+d12+d23.

[0032] Through the above design, the illumination effect of the entire illumination area can be relatively uniform, and the minimum relative illumination of the optical lens is greater than 80%, and the relative illumination value refers to the ratio of the illumination of any illumination area to the illumination of the central area. Generally, the central area illumination value is the largest, and the closer the relative illumination value is to 100%, the more uniform the illumination is.

[0033] Figure 1 and Figure 5 Figures 1 and 2 respectively show the specific structures of the first embodiment and the second embodiment of the small-aperture optical lens capable of achieving high resolution according to the present application, wherein the curvature radii of the light-incoming surface and the light-outgoing surface of the first lens 1 are R1 and R2 respectively, the curvature radii of the light-incoming surface and the light-outcoming surface of the second lens 2 are R3 and R4 respectively, and the curvature radii of the light-incoming surface and the light-outcoming surface of the third lens 3 are R5 and R6 respectively. Except that R1 is infinite (a plane), R2 and R6 are negative (both facing the front of the lamp), R3, R4 and R5 are positive (all facing the back of the lamp). The specific parameter values of the two embodiments are shown in Table 1.

[0034] For the first embodiment, the first lens 1 is a glass aspheric lens with an anti-reflection film, which is used to achieve better imaging effect.

[0035] The first lens 1 and the third lens 3 adopt high Abbe number (i.e. Abbe number Vd≥56), in the lens with high Abbe number, the refractive index of medium is smaller, the dispersion is lighter, the light can be prevented from spreading to the periphery, the second lens 2 adopts low Abbe number (i.e. Abbe number Vd≤30), in the lens with low Abbe number, the refractive index of medium is larger, the dispersion is more serious, and the high Abbe number and low refractive index material can be matched to achieve good achromatic effect. The refractive index of the first lens 1 is Nd1, the Abbe number is Vd1, the refractive index of the second lens 2 is Nd2, the Abbe number is Vd2, the refractive index of the third lens 3 is Nd3, and the Abbe number is Vd3.

[0036] According to Table 1, in the embodiment one, the combined focal length f (EFL) of the three lenses is 18.3 mm (between 15-21 mm), the maximum field angle generated by the optical lens is equal to 37.4° (greater than 35°), the focal length f2 of the second lens 2 is -12.94 mm (between -15- -10 mm), the total length L of the optical lens along the optical axis direction is 42.95 mm (less than 50 mm), and the maximum diagonal size IH of the rectangular area light source is 10 mm. The ratio of the focal length f3 of the third lens to the effective focal length f (EFL) of the optical lens is 1.67 (between 1.4- -1.9).

[0037] The application selects three characteristic wavelengths of 486 nm, 588 nm and 656 nm to test the axial chromatic aberration, the vertical chromatic aberration and the relative luminance through the optical lens in the visible light band. Figure 2-Figure 4 The simulation results show that in the optical lens of the embodiment one, the maximum difference of the axial chromatic aberration of each waveband is less than 0.8 mm, the maximum difference of the vertical chromatic aberration of each waveband is less than 60 um, and the relative luminance value is more than 80%.

[0038] For the embodiment two, the first lens 1 is a glass aspheric lens with an antireflection film, the first lens 1 and the third lens 3 adopt high Abbe number, and the second lens 2 adopts low Abbe number. According to Table 1, in the embodiment two, the combined focal length f (EFL) of the three lenses is 19.0 mm (between 15-21 mm), the maximum field angle generated by the optical lens is equal to 37.4° (greater than 35°), the focal length f2 of the second lens 2 is -14.5 mm (between -15- -10 mm), the total length L of the optical lens along the optical axis direction is 39.86 mm (less than 50 mm), and the maximum diagonal size IH of the rectangular area light source is 10 mm. The ratio of the focal length f3 of the third lens to the effective focal length f (EFL) of the optical lens is 1.5 (between 1.4- -1.9).

[0039] The present invention passes three characteristic lights with wavelengths of 486nm, 588nm and 656nm through the optical lens and performs tests on axial chromatic aberration, vertical chromatic aberration and relative illumination. Figure 6-Figure 8 The simulation results show that in the optical lens of Example 2, the overall axial chromatic aberration is very small, and the difference between the vertical chromatic aberration and the wavelengths in the entire image height range is small. The relative illumination values ​​are all above 90%.

[0040] Table 1

[0041]

[0042]

[0043] in,

[0044] f(EFL) represents the combined focal length of the three lenses;

[0045] f1 represents the focal length of the first lens 1;

[0046] f2 represents the focal length of the second lens 2;

[0047] f3 represents the focal length of the third lens 3;

[0048] f12 represents the combined focal length of the first lens 1 and the second lens 2;

[0049] L represents the total length of the optical lens in the optical axis direction;

[0050] IH represents the maximum diagonal size of the rectangular surface light source;

[0051] R1 represents the curvature radius of the incident surface of the first lens 1;

[0052] R2 represents the curvature radius of the light-emitting surface of the first lens 1;

[0053] R3 represents the curvature radius of the incident surface of the second lens 2;

[0054] R4 represents the curvature radius of the light-emitting surface of the second lens 2;

[0055] R5 represents the curvature radius of the incident surface of the third lens 3;

[0056] R6 represents the curvature radius of the light-emitting surface of the third lens 3;

[0057] D1 represents the outer diameter of the first lens 1;

[0058] D2 represents the outer diameter of the second lens 2;

[0059] D3 represents the outer diameter of the third lens 3;

[0060] Nd1 represents the refractive index of the first lens 1;

[0061] Nd2 represents the refractive index of the second lens 2;

[0062] Nd3 represents the refractive index of the third lens 3;

[0063] Vd1 represents the Abbe number of the first lens 1;

[0064] Vd2 represents the Abbe number of the second lens 2;

[0065] Vd3 represents the Abbe number of the third lens 3;

[0066] d1 represents the center thickness of the first lens 1;

[0067] d2 represents the center thickness of the second lens 2;

[0068] d3 represents the center thickness of the third lens 3;

[0069] d01 represents the air space between the light source surface and the first lens 1;

[0070] d12 represents the air space between the first lens 1 and the second lens 2;

[0071] d23 represents the air space between the second lens 2 and the third lens 3 .

[0072] In this specification, the schematic representations of the terms do not necessarily refer to the same embodiment. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments.

[0073] With the above-described preferred embodiments of the present invention as inspiration, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A small-aperture optical lens capable of achieving high resolution, characterized by: The total number of lenses in the optical lens is three. The three lenses are, in order from the light source (4) side to the outside, the first lens (1), the second lens (2), and the third lens (3); the first lens (1) and the third lens (3) have positive refractive powers, and the second lens (2) has negative refractive power; The incident light surface of the first lens (1) is a plane, the outgoing light surfaces of the first lens (1) and the third lens (3) are both curved surfaces facing the outside, and the incident light surfaces and the outgoing light surfaces of the second lens (2) and the incident light surface of the third lens (3) are all curved surfaces facing the light source (4); and the diameters of the first lens (1), the second lens (2), and the third lens (3) are all less than or equal to 30 mm; the combined focal length f (EFL) of the three lenses is 15 mm to 21 mm, and the maximum field angle generated by the optical lens is greater than 35°; the focal length of the second lens (2) is f2, then -15 mm < f2 < -10 mm; the focal length of the third lens (3) is f3, then 1.4 < f3 / f (EFL) < 1.

9.

2. The small-aperture optical lens capable of achieving high resolution according to claim 1, wherein: The diameter of the first lens (1) is 20 mm, the diameter of the second lens (2) is 28 mm, and the diameter of the third lens (3) is 30 mm.

3. The small-aperture optical lens capable of achieving high resolution according to claim 1, wherein: At least one of the three lenses is a glass aspherical lens with an anti-reflection coating.

4. The small-aperture optical lens capable of achieving high resolution according to claim 1, wherein: The Abbe numbers Vd of the first lens (1) and the third lens (3) are Vd ≥ 56; the Abbe number Vd of the second lens (2) is Vd ≤ 30.

5. The small-aperture optical lens capable of achieving high resolution according to claim 1, wherein: The light source (4) corresponding to the optical lens is a rectangular surface light source, and the maximum diagonal size IH of the rectangular surface light source is IH ≥ 10 mm.

6. The small-aperture optical lens capable of achieving high resolution according to claim 5, wherein: The total length L of the optical lens in the optical axis direction is L < 50 mm.

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