A five-element optical lens

Abstract

The present invention discloses a five-piece optical lens, which is composed of a first lens, an aperture, a second lens, a third lens, a fourth lens, and a fifth lens in order from the object side to the image side along the optical axis; the first lens has positive focal power and both the object side and the image side are convex; the second lens is configured as a meniscus lens with a convex object side, the third lens is configured as a meniscus lens with a convex object side; the fourth lens has positive focal power and both the object side and the image side are convex; either the second lens or the third lens is configured as a lens with negative focal power or both the second lens and the third lens are configured as lenses with negative focal power; the fifth lens is configured as a meniscus lens with positive focal power and is curved toward the image side. Brightness is improved and image resolution is suitable.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging display, and specifically discloses a five-piece optical lens. Background Art

[0002] Newly developed pixel headlights, also known as matrix headlights, utilize digital light projection technology, enabling headlights to function beyond mere illumination. These headlights can also project patterns on the ground, such as weather conditions, road navigation, or other symbols for pedestrians and other vehicles to identify, acting as a kind of light language. The optical system for pixel headlights requires luminous pixels—can be mini LEDs, microLEDs, LCD screens, LCOS, or illuminated DMD digital micromirrors—and an optical lens for projection. To ensure the projected pattern is clearly visible, the lens must achieve excellent optical performance, eliminating various optical aberrations such as chromatic aberration, field curvature, and astigmatism. Generally, a good optical lens utilizes a combination of multiple positive and negative lenses to eliminate aberrations. The specific number of optical lenses used depends on the optical system's parameters, performance indicators, and the optical materials and processes used. More complex optical systems can have more than 10 lenses, while current mobile phone lenses typically use six or more.

[0003] Pixel headlights combine lighting and imaging functions, requiring higher energy efficiency and brightness. Furthermore, high-quality products demand high image quality, particularly low color deviation. Furthermore, due to the unique characteristics of automotive applications, they require higher thermal and vibration reliability, lighter weight (due to weight reduction), and lower costs to remain competitive in the market.

[0004] Current lens designs either use more lenses, or use more expensive optical glass materials, or have low light energy utilization, or have low imaging quality. For example, China Authorization Announcement No. CN221079037U, with an authorization announcement date of June 4, 2024, discloses a large-aperture vehicle-mounted lens module and lens, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in sequence from the object side to the image side along the optical axis; the first lens has a negative optical power, the second lens has a negative optical power, the third lens has a positive optical power, the fourth lens has a positive optical power, the fifth lens is glued to the sixth lens and has a negative optical power, the seventh lens has a positive optical power, and the eighth lens has a positive optical power. The utility model provides a large-aperture vehicle-mounted lens module and lens that can achieve a larger aperture, a larger aperture, and a high resolution. In summary, pixel headlights must achieve high energy efficiency, meaning a large numerical aperture, and maintain relatively stable performance across a wide range of operating temperatures (-45°C to +85°C). This discussion demonstrates that pixel headlights must offer high energy efficiency, minimal color aberration, and high image resolution. Given these limitations, improvements are urgently needed. Summary of the Invention

[0005] Based on this, it is necessary to provide a five-piece optical lens for the projection system of smart pixel headlights such as automobile and motorcycle headlights to address the existing technical problems. It can improve the utilization rate of light energy and brightness by increasing the numerical aperture, and has good thermal stability.

[0006] To solve the problems of the prior art, the present invention discloses a five-element optical lens, which is composed of a first lens, an aperture, a second lens, a third lens, a fourth lens, and a fifth lens in order from the object side to the image side along the optical axis; the image side is the actual light-emitting surface;

[0007] The first lens has positive refractive power and both the object-side surface and the image-side surface are convex;

[0008] The second lens is a meniscus lens with a convex object side surface.

[0009] The third lens is configured as a meniscus lens with a convex object side surface;

[0010] The fourth lens has positive refractive power and both the object-side surface and the image-side surface are convex;

[0011] Either the second lens or the third lens is configured as a lens having negative optical power, or both the second lens and the third lens are configured as lenses having negative optical power;

[0012] The fifth lens is configured as a meniscus lens having positive optical power and curved toward the image side;

[0013] And it satisfies the following conditions:

[0014] R9 / R10<1.6, where R9 is the radius of curvature of the object side of the fifth lens, and R10 is the radius of curvature of the image side of the fifth lens;

[0015] |f123| / f>5, where |f123| is the equivalent focal length of the combined lens group of the first lens, the second lens, and the third lens, and f is the equivalent focal length of the system;

[0016] OAL / f<2.6, where OAL is the total operating length of the system;

[0017] D1 / OAL>0.6, D1 is the optical aperture of the first lens.

[0018] Preferably, the back focus of the five-piece optical lens is greater than 2 mm.

[0019] Preferably, the optical surfaces of the first lens, the second lens, the third lens, the fourth lens and the fifth lens are all set to be aspherical surfaces.

[0020] Preferably, the third lens and the fourth lens are glued together to form an integrated structure.

[0021] Preferably, any one of the fourth lens and the fifth lens is configured as a glass cemented lens or a lens composited into one body by different resin materials.

[0022] The beneficial effects of the present invention are: compared with traditional designs, energy utilization is high, performance is relatively stable under different operating temperatures, color difference is small, and image quality resolution is high. Specifically:

[0023] 1. Both the second and third lenses are meniscus lenses, which can reduce the field curvature of a large field of view and improve the imaging quality of a large field of view;

[0024] 2. The relationship R9 / R10 < 1.6 is satisfied. This constraint indicates that the image side surface of the fifth lens element is relatively flat, which is beneficial for guiding large-angle light into the optical lens, helping to improve the numerical aperture of the lens. In addition, its proximity to the image plane is beneficial for correcting field-related aberrations.

[0025] 3. The relationship |f123| / f>5 is satisfied. This constraint limits the optical power of the first, second, and third lenses in the system to a smaller value, which is beneficial for improving image quality. In addition, when the system uses a glass-plastic hybrid lens, it is considered that at least the fourth and fifth lenses are glass lenses, which can improve the thermal stability of the lens' optical performance under different temperature conditions.

[0026] 4. Satisfy the relationship OAL / f<2.6, so that the system has a smaller space requirement at the same optical power;

[0027] 5. Satisfying the relationship D1 / OAL>0.6 is beneficial to reducing the axial size of the system while increasing optical energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a structural diagram of embodiment 1 of the present invention.

[0029] Figure 2 This is an MTF curve diagram of Example 1 of the present invention.

[0030] Figure 3 This is the magnification chromatic aberration curve of Example 1 of the present invention.

[0031] Figure 4 This is a structural diagram of embodiment 2 of the present invention.

[0032] Figure 5 This is the MTF curve diagram of the second embodiment of the present invention.

[0033] Figure 6 This is the magnification chromatic aberration curve of Example 2 of the present invention.

[0034] Figure 7 This is a structural diagram of embodiment 3 of the present invention.

[0035] Figure 8 This is the MTF curve diagram of Example 3 of the present invention.

[0036] Figure 9 This is the magnification chromatic aberration curve of Example 3 of the present invention.

[0037] Reference numerals are: a first lens 11 , an aperture 10 , a second lens 12 , a third lens 13 , a fourth lens 14 , and a fifth lens 15 . DETAILED DESCRIPTION

[0038] In order to further understand the features, technical means, specific objectives and functions achieved by the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] refer to Figures 1 to 9 .

[0040] The basic embodiment of the present invention discloses a five-piece optical lens, which is composed of a first lens 11, an aperture 10, a second lens 12, a third lens 13, a fourth lens 14 and a fifth lens 15 in order from the object side to the image side along the optical axis; the image side is the actual light-emitting surface; the first lens 11 has positive focal power and both the object side and the image side are convex; the second lens 12 is configured as a meniscus lens with a convex object side, and the third lens 13 is configured as a meniscus lens with a convex object side; the fourth lens 14 has positive focal power and both the object side and the image side are convex; either the second lens 12 and the third lens 13 are configured as lenses with negative focal power or both the second lens 12 and the third lens 13 are configured as lenses with negative focal power; the fifth lens 15 is configured as a meniscus lens with positive focal power and is bent toward the image side; the second lens and the third lens are both configured as meniscus lenses, which can reduce field curvature at a large field of view, which is beneficial to improving imaging quality at a large field of view;

[0041] And it satisfies the following conditions:

[0042] R9 / R10<1.6, where R9 is the radius of curvature of the object-side surface of the fifth lens element 15, and R10 is the radius of curvature of the image-side surface of the fifth lens element 15. This constraint indicates that the image-side surface of the fifth lens element 15 is relatively flat, which facilitates guiding large-angle light into the optical lens, helping to increase the numerical aperture of the lens. Furthermore, its proximity to the image plane facilitates correction of field-related aberrations.

[0043] |f123| / f>5, where |f123| is the equivalent focal length of the combined lens group of the first lens 11, the second lens 12, and the third lens 13, and f is the equivalent focal length of the system. This constraint limits the optical power of the first, second, and third lenses in the system to a smaller value, which is beneficial for improving image quality. In addition, when the system is a glass-plastic hybrid lens, considering that at least the fourth and fifth lenses are glass lenses can improve the thermal stability of the lens' optical performance under different temperature conditions.

[0044] OAL / f<2.6, where OAL is the total working length of the system; this allows the system to have a smaller space requirement at the same optical power;

[0045] D1 / OAL>0.6, where D1 is the optical aperture of the first lens 11 , is beneficial for reducing the axial size of the system while increasing optical energy efficiency.

[0046] Preferably, the back focus of the five-piece optical lens is greater than 2 mm.

[0047] Preferably, the optical surfaces of the first lens 11 , the second lens 12 , the third lens 13 , the fourth lens 14 and the fifth lens 15 are all set to be aspherical surfaces.

[0048] Preferably, the third lens 13 and the fourth lens 14 are glued together to form an integrated structure.

[0049] Preferably, any one of the fourth lens 14 and the fifth lens 15 is configured as a glass cemented lens or a lens composited into one body by different resin materials.

[0050] Example 1: This embodiment limits the second lens 12 and the third lens 13 to be negative lenses. The structure of this embodiment is as follows: Figure 1 As shown, the MTF curve is as follows Figure 2 As shown, the magnification chromatic aberration curve Figure 3 As shown in the accompanying drawings, it can be seen that the magnification chromatic aberration of the system is very small. The following are the surface parameters of this embodiment.

[0051] Table 1

[0052]

[0053]

[0054] Table 2

[0055]

[0056] The expression for aspheric surface is as follows:

[0057]

[0058] Where z is the sag at position r of the aspheric surface; c is the paraxial curvature of the aspheric surface, c = 1 / R, (i.e., the paraxial curvature c is the inverse of the surface curvature radius R); k is the cone coefficient; A, B,.., J are high-order coefficients.

[0059] Table 3 (Other system parameters of this embodiment are)

[0060]

[0061] Table 4, Constraints of Example 1

[0062] Constraints Design Results |R1|>|R2| From the design table, know satisfaction <h2 style=";text-align:left;direction:ltr">R9 / |R10|<1.6<h2 style=";text-align:left;direction:ltr"> R9 / |R10|=0.83, knowing satisfaction |f123| / f>5 |f123| / f=11.2, contentment OAL / f<2.6 OAL / f=1.89, satisfied D1 / OAL>0.6 D1 / OAL=0.71, knowing satisfaction

[0063] Example 2: This embodiment defines that the third lens 13 is an aspheric lens. The structure of this embodiment is as follows: Figure 4 As shown, the MTF curve is as follows Figure 5 As shown, the magnification chromatic aberration curve Figure 6 As shown in the accompanying drawings, it can be seen that the magnification chromatic aberration of the system is very small. The following are the surface parameters of this embodiment.

[0064] Table 5

[0065]

[0066]

[0067] The expression for aspheric surface is as follows:

[0068]

[0069] Where z is the sag at position r of the aspheric surface; c is the paraxial curvature of the aspheric surface, c = 1 / R, (i.e., the paraxial curvature c is the inverse of the surface curvature radius R); k is the cone coefficient; A, B,.., J are high-order coefficients.

[0070] Table 6

[0071]

[0072] Table 7

[0073]

[0074] Table 8, Constraints of Example 2

[0075] Constraints Design Results |R1|>|R2| From the design table, know satisfaction <h2 style=";text-align:left;direction:ltr">R9 / |R10|<1.6<h2 style=";text-align:left;direction:ltr"> R9 / |R10|=0.52, knowing satisfaction |f123| / f>5 |f123| / f=16.7, contentment OAL / f<2.6 OAL / f=1.77, satisfied D1 / OAL>0.6 D1 / OAL=0.75, knowing satisfaction

[0076] In the third embodiment, the third lens 13 and the fourth lens 14 are glued together to form an integrated structure. The structure of this embodiment is as follows: Figure 7 As shown, the MTF curve is as follows Figure 8 As shown, the magnification chromatic aberration curve Figure 9 As shown in the accompanying drawings, it can be seen that the magnification chromatic aberration of the system is very small. The following are the surface parameters of this embodiment.

[0077] Table 9

[0078]

[0079]

[0080] The expression for aspheric surface is as follows:

[0081]

[0082] Where z is the sag at position r of the aspheric surface; c is the paraxial curvature of the aspheric surface, c = 1 / R, (i.e., the paraxial curvature c is the inverse of the surface curvature radius R); k is the cone coefficient; A, B,.., J are high-order coefficients.

[0083] Table 10

[0084]

[0085] Table 11

[0086]

[0087] Table 12, Constraints of Example 3

[0088] Constraints Design Results |R1|>|R2| From the design table, know satisfaction <h2 style=";text-align:left;direction:ltr">R9 / |R10|<1.6<h2 style=";text-align:left;direction:ltr"> R9 / |R10|=0.98, knowing satisfaction |f123| / f>5 |f123| / f=7.88, contentment OAL / f<2.6 OAL / f=2.02, satisfied D1 / OAL>0.6 D1 / OAL=0.68, contentment

[0089] The above-described embodiments merely represent three implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A five-element optical lens, characterized in that: The lens is composed of a first lens (11), an aperture (10), a second lens (12), a third lens (13), a fourth lens (14), and a fifth lens (15) in sequence from the object side to the image side along the optical axis; The first lens (11) has positive optical power and both the object side surface and the image side surface are convex; The second lens (12) is configured as a meniscus lens with a convex object side surface. The third lens (13) is configured as a meniscus lens with a convex object side surface; The fourth lens (14) has positive optical power and both the object side surface and the image side surface are convex; The second lens (12) and the third lens (13) are both configured as lenses with negative optical power; The fifth lens (15) is configured as a meniscus lens having positive optical power and is curved toward the image side; And it satisfies the following conditions: R9 / R10<1.6, wherein R9 is the radius of curvature of the object side of the fifth lens (15), and R10 is the radius of curvature of the image side of the fifth lens (15); |f123| / f>5, wherein |f123| is the equivalent focal length of the combined lens group of the first lens (11), the second lens (12), and the third lens (13), and f is the equivalent focal length of the system; OAL / f<2.6, where OAL is the total operating length of the system; D1 / OAL>0.6, D1 is the optical aperture of the first lens (11).

2. The five-piece optical lens according to claim 1, wherein: The back focus distance of the five-element optical lens is greater than 2mm.

3. The five-piece optical lens according to claim 1, wherein: The optical surfaces of the first lens (11), the second lens (12), the third lens (13), the fourth lens (14) and the fifth lens (15) are all configured as aspherical surfaces.

4. The five-element optical lens according to claim 1, wherein: The third lens (13) and the fourth lens (14) are glued together to form an integrated structure.

5. The five-piece optical lens according to claim 1, wherein: Any one of the fourth lens (14) and the fifth lens (15) is configured as a glass cemented lens or a lens composited into one body by different resin materials.

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