Lens assembly, shooting device and cooking equipment

Abstract

The invention relates to the technical field of optical lenses, particularly provides a lens assembly, a shooting device and cooking equipment, and at least solves the problem that an existing lens assembly is poor in imaging definition at ultrahigh temperature. The lens assembly at least comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged in the light incident direction, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a convex surface; the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a concave surface; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; the object side surface of the sixth lens is a plane, and the image side surface of the sixth lens is a plane; the first lens and the second lens are spherical lenses, the third lens, the fourth lens and the fifth lens are aspheric lenses, and the sixth lens is an optical filter. The lens assembly has good relative illumination in a high-temperature environment, optical distortion is relatively small, and clear imaging can still be achieved in the high-temperature environment.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, specifically providing a lens assembly, a shooting device, and a cooking appliance. Background Technology

[0002] In modern cooking scenarios, some devices, such as ovens and air fryers, often operate at extremely high temperatures, typically reaching or exceeding 200 degrees Celsius, to satisfy users' pursuit of the ultimate baking and crisping effects. With the increasing demand for visualization of the cooking process, more and more people are keen to record changes in food shape during baking, observe the dynamic characteristics of food surfaces such as charring and bubbling under high temperatures in real time, and share the cooking process by filming, extending the experience from "taste experience" to "visual sharing." Therefore, these devices are generally equipped with camera modules to support real-time image acquisition.

[0003] However, ultra-high temperature environments pose a severe challenge to optical imaging systems: high temperatures cause lens materials to expand and deform due to heat, leading to problems such as image blurring, decreased contrast, and loss of detail, directly affecting the user's visual experience and sharing effect of the cooking process. Specifically, lens thermal deformation can easily cause multiple optical defects. For example, a significant reduction in relative illumination leads to distortion in the transition between light and dark areas of the image, and increased optical distortion causes deformation and distortion in edge areas. Ultimately, the captured image cannot clearly present key details such as the caramelization process and bubbling dynamics of food, reducing the viewing experience and professionalism of the content shared by the user. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned technical problems, namely, to at least solve the problem of poor image clarity of existing lens assemblies at ultra-high temperatures.

[0005] In a first aspect, the present invention provides a lens assembly comprising at least the following elements arranged sequentially along the direction of light incidence: a first lens having a planar object-side surface and a concave image-side surface; a second lens having a convex object-side surface and a convex image-side surface; a third lens having a concave object-side surface and a convex image-side surface; a fourth lens having a concave object-side surface and a concave image-side surface; a fifth lens having a convex object-side surface and a convex image-side surface; and a sixth lens having a planar object-side surface and a planar image-side surface; wherein the first and second lenses are spherical lenses, the third, fourth, and fifth lenses are aspherical lenses, and the sixth lens is a light filter.

[0006] In some feasible embodiments of the lens assembly described above, the first lens, the second lens, and the sixth lens are made of glass, while the third lens, the fourth lens, and the fifth lens are made of plastic.

[0007] In some feasible embodiments of the lens assembly described above, the image-side surface of the first lens is a concave spherical surface with a radius of curvature ranging from [2.516 mm to 2.916 mm]; the object-side surface of the second lens is a convex spherical surface with a radius of curvature ranging from [7.475 mm to 7.875 mm]; the image-side surface of the second lens is a convex spherical surface with a radius of curvature ranging from [-5.61 mm to -5.21 mm]; the object-side surface of the third lens is a concave aspherical surface with a vertex radius of curvature ranging from [-94.868 mm to -94.468 mm]; the image-side surface of the third lens is a convex aspherical surface with a vertex radius of curvature ranging from [-94.868 mm to -94.468 mm]; the object-side surface of the third lens is a convex aspherical surface with a vertex radius of curvature ranging from [-94.868 mm to -94.468 mm]. The radius of curvature of the fourth lens is in the range of [-12.678mm, -12.278mm]; the object side of the fourth lens is a concave aspherical surface with a vertex radius of curvature in the range of [-3.869mm, -3.469mm]; the image side of the fourth lens is a concave aspherical surface with a vertex radius of curvature in the range of [11.348mm, 11.748mm]; the object side of the fifth lens is a convex aspherical surface with a vertex radius of curvature in the range of [4.344mm, 4.744mm]; the image side of the fifth lens is a convex aspherical surface with a vertex radius of curvature in the range of [-6.599mm, -6.199mm].

[0008] In some feasible embodiments of the lens assembly described above, the radius of curvature of the image-side surface of the first lens is 2.716 mm, the radius of curvature of the object-side surface of the second lens is 7.675 mm, the radius of curvature of the image-side surface of the second lens is -5.41 mm, the vertex radius of curvature of the object-side surface of the third lens is -94.668 mm, the vertex radius of curvature of the image-side surface of the third lens is -12.478 mm, the vertex radius of curvature of the object-side surface of the fourth lens is -3.669 mm, the vertex radius of curvature of the image-side surface of the fourth lens is 11.548 mm, the vertex radius of curvature of the object-side surface of the fifth lens is 4.544 mm, and the vertex radius of curvature of the image-side surface of the fifth lens is -6.399 mm.

[0009] In some feasible embodiments of the lens assembly described above, the aspherical parameters of the object-side surface of the third lens are: R=-94.668, K=-926.003, A2=0, A4=-0.011049742, A6=-0.0028379688, A8=0.00073168256, A10=-0.00022827222, A12=4.0905797e-05, A14=-3.0356861e-06; the aspherical parameters of the image-side surface of the third lens are: R=-12.478, K=10.044, A2=0, A4=-0.02035. 2132, A6=0.003638839, A8=-0.0012961866, A10=3.553437e-05, A12=3.553437e-05, A14=-7.1446161e-06; The aspherical parameters of the object side of the fourth lens are: R=-3.669, K=-5.837, A2=0, A4=0.0039305581, A6=0.0010338095, A8=-0.0006572453, A10=-7.1205873e-05, A12=5.8197923e-05, A14=-6 The aspherical parameters of the image side of the fourth lens are: R=11.548, K=-39.785, A2=0, A4=0.023370919, A6=-0.0044710717, A8=0.0007331783, A10=-6.8405182e-05, A12=-3.2780146e-06, A14=6.6690007e-07; the aspherical parameters of the object side of the fifth lens are: R=4.544, K=-7.964, A2=0, A4=0.0056051473, A6=-0.00 066757209, A8=-4.6359966e-06, A10=3.0313165e-05, A12=-5.4752154e-06, A14=1.6260105e-07; The aspherical parameters of the image side of the fifth lens are: R=-6.399, K=0, A2=0, A4=0.0021911968, A6=-4.0829074e-05, A8=7.925455e-05, A10=-3.6963363e-05, A12=6.482164e-06, A14=-4.3105005e-07.

[0010] In some feasible embodiments of the lens assembly described above, the air gap between the first lens and the second lens ranges from [4.983mm, 5.083mm]; the air gap between the second lens and the third lens ranges from [0.256mm, 0.356mm]; the air gap between the third lens and the fourth lens ranges from [0.063mm, 0.163mm]; the air gap between the fourth lens and the fifth lens ranges from [0.04mm, 0.14mm]; and the air gap between the fifth lens and the sixth lens ranges from […]. [0.038mm, 0.138mm]; and / or, the center thickness of the first lens ranges from [0.7mm, 0.9mm], the center thickness of the second lens ranges from [2.56mm, 2.76mm], the center thickness of the third lens ranges from [0.98mm, 1.18mm], the center thickness of the fourth lens ranges from [0.72mm, 0.92mm], the center thickness of the fifth lens ranges from [1.646mm, 1.846mm], and the center thickness of the sixth lens ranges from [0.90mm, 1.10mm].

[0011] In some feasible embodiments of the lens assembly described above, the air gap between the first lens and the second lens is 5.033 mm, the air gap between the second lens and the third lens is 0.306 mm, the air gap between the third lens and the fourth lens is 0.113 mm, the air gap between the fourth lens and the fifth lens is 0.09 mm, and the air gap between the fifth lens and the sixth lens is 0.088 mm; and / or, the center thickness of the first lens is 0.8 mm, the center thickness of the second lens is 2.66 mm, the center thickness of the third lens is 1.08 mm, the center thickness of the fourth lens is 0.82 mm, the center thickness of the fifth lens is 1.746 mm, and the center thickness of the sixth lens is 1.00 mm.

[0012] In some feasible embodiments of the lens assembly described above, the refractive index of the first lens is 1.59279±5%, the refractive index of the second lens is 1.8348±5%, the refractive index of the third lens is 1.53116±5%, the refractive index of the fourth lens is 1.6613±5%, the refractive index of the fifth lens is 1.53116±5%, and the refractive index of the sixth lens is 1.5168±5%.

[0013] In a second aspect, the present invention also provides a shooting device, the shooting device comprising the lens assembly described in any of the foregoing technical solutions.

[0014] In a third aspect, the present invention also provides a cooking device, the cooking device including the imaging device described in any of the foregoing technical solutions.

[0015] The beneficial effects of this invention are: This invention employs a multi-lens collaborative design to achieve high-fidelity imaging under high-temperature conditions. The first and second lenses, composed of spherical lenses, form the foundation for imaging stability. The third, fourth, and fifth lenses, composed of aspherical lenses, utilize surface optimization technology to achieve reverse compensation for thermal expansion deformation and complementary stress cancellation. Combined with a filter in the sixth lens, this effectively suppresses stray light from high temperatures, resulting in an imaging effect of "structural stability - deformation compensation - light pollution filtering." This design ensures that the lens assembly maintains good relative illumination and relatively low optical distortion even under high-temperature operating conditions, guaranteeing clear imaging of key dynamic details such as food caramelization and bubbling, thus meeting users' high-quality needs for visual visualization and sharing of the cooking process. Attached Figure Description

[0016] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of the optical path structure of a lens assembly provided in an embodiment of the present invention; Figure 2 A schematic diagram of the optical path structure of a lens assembly with dimensions provided in an embodiment of the present invention; Figure 3 A schematic diagram illustrating the optical modulation and demodulation function performance of a lens assembly provided in an embodiment of the present invention; Figure 4 A schematic diagram illustrating the optical transfer function performance of a lens assembly provided in an embodiment of the present invention; Figure 5 A schematic diagram illustrating the relative illumination performance of a lens assembly provided in an embodiment of the present invention; Figure 6 A schematic diagram illustrating the optical distortion performance of a lens assembly provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the optical dot array of a lens assembly provided in an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Photosensitive element. Detailed Implementation

[0018] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the invention and are not intended to limit the scope of protection of the invention. Those skilled in the art can make adjustments as needed to adapt to specific applications. Numerous specific details are set forth in the following detailed description to better illustrate the invention. Those skilled in the art should understand that the invention can be practiced without certain specific details.

[0019] In the description of this invention, terms such as "upper," "lower," "inner," "outer," "left," "right," "front," and "rear," which indicate direction or positional relationships, are based on actual application and are used merely for ease of description. They do not indicate or imply that the device to be protected must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. Furthermore, ordinal numbers such as "first" and "second" are used only for convenience and are not intended to indicate or imply relative importance.

[0020] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] Please see Figure 1 and Figure 2 The present invention provides a lens assembly comprising at least the following elements arranged sequentially along the direction of light incidence: a first lens 1, having a planar object-side surface and a concave image-side surface; a second lens 2, having a convex object-side surface and a convex image-side surface; a third lens 3, having a concave object-side surface and a convex image-side surface; a fourth lens 4, having a concave object-side surface and a concave image-side surface; a fifth lens 5, having a convex object-side surface and a convex image-side surface; and a sixth lens 6, having a planar object-side surface and a planar image-side surface; wherein the first lens 1 and the second lens 2 are spherical lenses, the third lens 3, the fourth lens 4 and the fifth lens 5 are aspherical lenses, and the sixth lens 6 is a filter.

[0022] It should be noted that the first lens 1 faces the object to be photographed, while the sixth lens 6 is away from the object to be photographed and close to the photosensitive element 7.

[0023] The first lens (1) and second lens (2) employ a spherical structure, whose geometric symmetry effectively resists thermal stress concentration, providing fundamental imaging stability for the system. The third lens (3), fourth lens (4), and fifth lens (5) incorporate aspherical surface optimization technology. By precisely controlling the mirror curvature distribution, they achieve reverse compensation for thermal expansion deformation and stress offsetting, effectively suppressing optical distortion caused by high temperatures. The sixth lens (6), as a dedicated filter, specifically filters out stray light interference generated in high-temperature environments, maintaining stable relative illumination of the image. Furthermore, by adjusting the concavity and convexity of the object-side and image-side surfaces of the six lenses, light can be focused onto the imaging surface, effectively improving the image quality of the lens assembly.

[0024] Furthermore, the first lens 1, the second lens 2, and the sixth lens 6 are made of glass, while the third lens 3, the fourth lens 4, and the fifth lens 5 are made of plastic. In other words, the first lens 1, the second lens 2, and the sixth lens 6 are all glass lenses, while the third lens 3, the fourth lens 4, and the fifth lens 5 are all plastic lenses. Through reasonable surface design and material selection, the entire lens assembly is made smaller and lighter, effectively reducing lens cost and weight while ensuring clear imaging results. This allows the lens assembly, when mounted on the imaging module, to capture clear and bright images, meeting the needs of cooking equipment for capturing clear images.

[0025] In one embodiment, the first lens 1 is made of H-ZPK5 glass, the second lens 2 is made of H-ZLAF55D glass, the third lens 3 is made of E48R plastic, the fourth lens 4 is made of EP-8000 plastic, the fifth lens 5 is made of E48R plastic, and the sixth lens 6 is made of H-K9L glass. In other embodiments, the first to sixth lenses 6 can be made of other optical materials with high-temperature resistance to meet the operating temperature requirements of cooking equipment such as ovens and air fryers. The specific materials can be designed according to the actual application scenario, and will not be described in detail in this embodiment.

[0026] In this embodiment, the image-side surface of the first lens 1 is a concave spherical surface with a radius of curvature ranging from [2.516 mm to 2.916 mm]; the object-side surface of the second lens 2 is a convex spherical surface with a radius of curvature ranging from [7.475 mm to 7.875 mm]; the image-side surface of the second lens 2 is a convex spherical surface with a radius of curvature ranging from [-5.61 mm to -5.21 mm]; the object-side surface of the third lens 3 is a concave aspherical surface with a vertex radius of curvature ranging from [-94.868 mm to -94.468 mm]; the image-side surface of the third lens 3 is a convex aspherical surface with a vertex radius of curvature ranging from... [-12.678mm, -12.278mm]; The object side of the fourth lens 4 is a concave aspherical surface, and its vertex radius of curvature ranges from [-3.869mm, -3.469mm]; The image side of the fourth lens 4 is a concave aspherical surface, and its vertex radius of curvature ranges from [11.348mm, 11.748mm]; The object side of the fifth lens 5 is a convex aspherical surface, and its vertex radius of curvature ranges from [4.344mm, 4.744mm]; The image side of the fifth lens 5 is a convex aspherical surface, and its vertex radius of curvature ranges from [-6.599mm, -6.199mm].

[0027] Preferably, the radius of curvature of the image side of the first lens 1 is 2.716 mm, the radius of curvature of the object side of the second lens 2 is 7.675 mm, the radius of curvature of the image side of the second lens 2 is -5.41 mm, the radius of curvature of the vertex of the object side of the third lens 3 is -94.668 mm, the radius of curvature of the vertex of the image side of the third lens 3 is -12.478 mm, the radius of curvature of the vertex of the object side of the fourth lens 4 is -3.669 mm, the radius of curvature of the vertex of the image side of the fourth lens 4 is 11.548 mm, the radius of curvature of the vertex of the object side of the fifth lens 5 is 4.544 mm, and the radius of curvature of the vertex of the image side of the fifth lens 5 is -6.399 mm.

[0028] By rationally designing the curvature radius range of the first lens 1 to the fifth lens 5, the thermal expansion reverse compensation, aberration precise control and material property matching can be achieved through the coordinated optimization of geometric parameters and thermophysical properties in ultra-high temperature environments, ultimately ensuring imaging stability.

[0029] Furthermore, when the object-side surface of the third lens 3 is a concave aspherical surface and the image-side surface of the third lens 3 is a convex aspherical surface, the aspherical parameters of the object-side surface of the third lens 3 are: R=-94.668, K=-926.003, A2=0, A4=-0.011049742, A6=-0.0028379688, A8=0.00073168256, A10=-0.00022827222, A12=4.090579 7e-05, A14=-3.0356861e-06; The aspherical parameters of the image side of the third lens 3 are: R=-12.478, K=10.044, A2=0, A4=-0.020352132, A6=0.003638839, A8=-0.0012961866, A10=3.553437e-05, A12=3.553437e-05, A14=-7.1446161e-06.

[0030] Furthermore, when the object side of the fourth lens 4 is a concave aspherical surface and the image side of the fourth lens 4 is also a concave aspherical surface, the aspherical parameters of the object side of the fourth lens 4 are: R=-3.669, K=-5.837, A2=0, A4=0.0039305581, A6=0.0010338095, A8=-0.0006572453, A10=-7.1205873e-05, A12=5.8197923e-0 5. A14 = -6.4668442e-06; The aspherical parameters of the image side of the fourth lens 4 are: R = 11.548, K = -39.785, A2 = 0, A4 = 0.023370919, A6 = -0.0044710717, A8 = 0.0007331783, A10 = -6.8405182e-05, A12 = -3.2780146e-06, A14 = 6.6690007e-07.

[0031] Furthermore, when the object-side surface of the fifth lens 5 is a convex aspherical surface, and the image-side surface of the fifth lens 5 is also a convex aspherical surface, the aspherical parameters of the object-side surface of the fifth lens 5 are: R=4.544, K=-7.964, A2=0, A4=0.0056051473, A6=-0.00066757209, A8=-4.6359966e-06, A10=3.0313165e-05, A12=-5.475215 4e-06, A14=1.6260105e-07; The aspherical parameters of the image side of the fifth lens 5 are: R=-6.399, K=0, A2=0, A4=0.0021911968, A6=-4.0829074e-05, A8=7.925455e-05, A10=-3.6963363e-05, A12=6.482164e-06, A14=-4.3105005e-07.

[0032] By rationally designing the aspherical parameters of the third lens 3 to the fifth lens 5, the direction and magnitude of lens deformation after thermal expansion are effectively controlled, so that the third lens 3 to the fifth lens 5 form reverse deformation compensation after thermal expansion, effectively offsetting the optical system misalignment caused by material thermal expansion, maintaining low distortion and high relative illumination, thereby ensuring the imaging quality of the lens assembly.

[0033] In this embodiment, the air gap between the first lens 1 and the second lens 2 is [4.983mm, 5.083mm]; the air gap between the second lens 2 and the third lens 3 is [0.256mm, 0.356mm]; the air gap between the third lens 3 and the fourth lens 4 is [0.063mm, 0.163mm]; the air gap between the fourth lens 4 and the fifth lens 5 is [0.04mm, 0.14mm]; and the air gap between the fifth lens 5 and the sixth lens 6 is [0.038mm, 0.138mm].

[0034] Preferably, the air gap between the first lens 1 and the second lens 2 is 5.033 mm, the air gap between the second lens 2 and the third lens 3 is 0.306 mm, the air gap between the third lens 3 and the fourth lens 4 is 0.113 mm, the air gap between the fourth lens 4 and the fifth lens 5 is 0.09 mm, and the air gap between the fifth lens 5 and the sixth lens 6 is 0.088 mm.

[0035] By rationally designing the air gap range between the first lens 1 to the sixth lens 6, both a buffer space for thermal expansion of the lenses is provided to maintain the stability of the system's conjugate relationship, and the optical path refraction path and aberration distribution are optimized through precise spacing control, thereby ensuring the imaging quality of the lens assembly with low distortion and high relative illumination in high-temperature environments.

[0036] In this embodiment, the center thickness of the first lens 1 ranges from [0.7mm, 0.9mm], the center thickness of the second lens 2 ranges from [2.56mm, 2.76mm], the center thickness of the third lens 3 ranges from [0.98mm, 1.18mm], the center thickness of the fourth lens 4 ranges from [0.72mm, 0.92mm], the center thickness of the fifth lens 5 ranges from [1.646mm, 1.846mm], and the center thickness of the sixth lens 6 ranges from [0.90mm, 1.10mm].

[0037] Preferably, the center thickness of the first lens 1 is 0.8 mm, the center thickness of the second lens 2 is 2.66 mm, the center thickness of the third lens 3 is 1.08 mm, the center thickness of the fourth lens 4 is 0.82 mm, the center thickness of the fifth lens 5 is 1.746 mm, and the center thickness of the sixth lens 6 is 1.00 mm.

[0038] By rationally designing the center thickness range of the first lens 1 to the sixth lens 6, the heat capacity and heat conduction efficiency of the lens can be precisely controlled, thereby dominating the deformation amplitude and direction after thermal expansion, and enabling thermal deformation to actively adapt to the needs of the optical system. Specifically, a reasonable thickness range can guide thermal expansion in a direction conducive to image stability. For example, aspherical lenses can form reverse deformation compensation through center thickness optimization, effectively offsetting the light path deviation caused by material expansion. At the same time, thickness gradient design can balance the thermal stress distribution of the lens, avoiding thermal stress concentration and aberration deterioration caused by excessive thickness in the central area, or insufficient structural strength and risk of deformation runaway caused by excessive thinness.

[0039] In this embodiment, the refractive index of the first lens 1 is 1.59279±5%, the refractive index of the second lens 2 is 1.8348±5%, the refractive index of the third lens 3 is 1.53116±5%, the refractive index of the fourth lens 4 is 1.6613±5%, the refractive index of the fifth lens 5 is 1.53116±5%, and the refractive index of the sixth lens 6 is 1.5168±5%.

[0040] Preferably, the refractive index of the first lens 1 is 1.59279, the refractive index of the second lens 2 is 1.8348, the refractive index of the third lens 3 is 1.53116, the refractive index of the fourth lens 4 is 1.6613, the refractive index of the fifth lens 5 is 1.53116, and the refractive index of the sixth lens 6 is 1.5168.

[0041] By rationally designing the refractive index range of the first lens 1 to the sixth lens 6, stable imaging quality under ultra-high temperature environment can be achieved through optical-thermal physics synergistic optimization. This not only utilizes the precise control of light by materials with different refractive indices to reduce aberrations such as spherical aberration and coma, but also ensures that refractive index drift is controllable under high temperature environment through the matching design of refractive index and temperature change, ultimately maintaining low distortion and high relative illumination imaging effect.

[0042] Table 1 below lists the optical parameters of each lens element in a lens assembly provided in an embodiment of this application: In this designation, G1 is the first lens (1), G2 is the second lens (2), P3 is the third lens (3), P4 is the fourth lens (4), P5 is the fifth lens (5), and G6 is the sixth lens (6). R1 ​​represents the object-side side of the lens, i.e., the object-side surface. R2 represents the image-side side of the lens, i.e., the image-side surface. R represents the radius of curvature (or vertex radius of curvature) of the object-side or image-side surface of each lens. Nd represents the refractive index of each lens.

[0043] Please see Figure 2 In this embodiment, the focal length of the optical lens is f=3.35mm, which can work within a working distance of 300mm; the aperture is F / N0=2.0, the optical back focal length is 4mm, and the distance from the outer surface of the first lens 1 to the central axis of the imaging plane is 17.75mm.

[0044] Figure 3 Table 1 shows the optical modulation and demodulation function performance of the lens assembly. The vertical axis OTF modulus (MTF) reflects the contrast transfer capability, and the horizontal axis spatial frequency (period) characterizes the detail size. Multiple curves correspond to the resolution performance at different field of view positions (center / edge). The more concentrated the curves are and the closer they are to 1, the more clearly the lens can image in the entire field of view (from the center to the edge).

[0045] Figure 4 Table 1 shows the optical transfer function performance of the lens assembly. The vertical axis represents the OTF modulus (MTF), and the horizontal axis represents the focal shift curve. By quantifying the contrast transfer capability of the optical system under different focal shifts, it directly reflects the lens's stability of depth of focus, thermal focal shift compensation effect, and uniformity of full-field imaging. The narrow focal shift range and the MTF curve concentrated close to 1 indicate that the system can still maintain high-resolution imaging under temperature changes or assembly errors, ensuring that details such as food caramelization bubbles and surface textures are clearly distinguishable during dynamic monitoring.

[0046] Figure 5 Table 1 shows the relative illumination curves for the lens components. Relative illumination represents the brightness ratio between the image edges and the center. Higher relative illumination results in better image uniformity and a sharper image. Figure 5As shown in Table 1, the relative illumination of the lens assembly is greater than 61%.

[0047] Figure 6 Table 1 shows the distortion curves of the lens assembly. The closer the curve is to the central baseline, the better the lens's distortion performance. A smaller distortion percentage indicates higher image quality and less image deformation. The lens assembly shown in Table 1 has a TV distortion of less than 10.7%, resulting in minimal image distortion and high image quality.

[0048] Figure 7 Table 1 shows a schematic diagram of the optical dot array of the lens assembly. This diagram visually quantifies aberration control and image sharpness by tracing the intersection points of light rays on the image plane. A denser, more symmetrical, and smaller-diameter dot array indicates superior suppression of aberrations such as spherical and coma, enabling clear rendering of micrometer-level details. Simultaneously, thermal expansion deformation compensation maintains the stability of the dot array at high temperatures, ensuring uniformity and low distortion across the entire field of view.

[0049] In summary, the lens assembly provided in this embodiment, by setting up 6 lenses and reasonably limiting the relevant parameter range of the lenses, enables the lens assembly to have a high image acquisition resolution, a relative illumination greater than 61%, and a TV distortion of less than 10.7%, and can clearly image in the 420nm to 680nm band with high image quality.

[0050] Based on the aforementioned lens assembly structure, the present invention also provides an imaging device, which includes the lens assembly described in any of the foregoing technical solutions. Specifically, the imaging device includes a lens assembly, an imaging sensor, and an image processor, among other components.

[0051] Based on the aforementioned lens assembly and shooting device structure, the present invention also provides a cooking device, which includes the shooting device described in any of the foregoing technical solutions. Specifically, the cooking device can be an oven, or an ultra-high temperature cooking appliance such as an air fryer.

[0052] This invention employs a multi-lens collaborative design to achieve high-fidelity imaging under high-temperature conditions. The spherical lenses of the first and second lenses (1 and 2) form the foundation for imaging stability. The aspherical lenses of the third, fourth, and fifth lenses (3, 4, and 5) utilize surface optimization technology to achieve reverse compensation for thermal expansion deformation and complementary stress cancellation. Combined with the filter of the sixth lens (6), this effectively suppresses stray light from high temperatures, resulting in an imaging effect of "structural stability - deformation compensation - light pollution filtering." This design ensures that the lens assembly maintains good relative illumination and relatively low optical distortion even under high-temperature operating conditions, guaranteeing clear imaging of key dynamic details such as food caramelization and bubbling, thus meeting users' high-quality needs for visual visualization and sharing of the cooking process.

[0053] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A lens assembly, characterized in that, The lens assembly includes at least the following components arranged sequentially along the direction of light incidence: The first lens (1) has a flat object side and a concave image side; The second lens (2) has a convex object side and a convex image side; The third lens (3) has a concave side surface and a convex side surface for its image; The fourth lens (4) has a concave side surface for both the object and the image sides. The fifth lens (5) has a convex object side and a convex image side; The sixth lens (6) has a plane on its object side and a plane on its image side; Among them, the first lens (1) and the second lens (2) are spherical lenses, the third lens (3), the fourth lens (4) and the fifth lens (5) are aspherical lenses, and the sixth lens (6) is a filter.

2. The lens assembly according to claim 1, characterized in that, The first lens (1), the second lens (2) and the sixth lens (6) are made of glass, while the third lens (3), the fourth lens (4) and the fifth lens (5) are made of plastic.

3. The lens assembly according to claim 1, characterized in that, The image-side surface of the first lens (1) is a concave spherical surface with a radius of curvature ranging from [2.516 mm to 2.916 mm]. The object side of the second lens (2) is a convex spherical surface with a radius of curvature ranging from [7.475 mm to 7.875 mm]. The image-side surface of the second lens (2) is a convex spherical surface with a radius of curvature ranging from -5.61 mm to -5.21 mm. The object side of the third lens (3) is a concave aspherical surface, and the radius of curvature of its vertex is in the range of [-94.868mm, -94.468mm]; The image-side surface of the third lens (3) is a convex aspherical surface, and the radius of curvature at its vertex ranges from -12.678 mm to -12.278 mm. The object side of the fourth lens (4) is a concave aspherical surface, and the radius of curvature at its vertex ranges from -3.869 mm to -3.469 mm. The image side of the fourth lens (4) is a concave aspherical surface, and the radius of curvature at its vertex ranges from [11.348 mm to 11.748 mm]. The object side of the fifth lens (5) is a convex aspherical surface, and the radius of curvature of its vertex is in the range of [4.344 mm, 4.744 mm]. The image side of the fifth lens (5) is a convex aspherical surface, and the radius of curvature at its vertex ranges from -6.599 mm to -6.199 mm.

4. The lens assembly according to claim 3, characterized in that, The first lens (1) has an image-side radius of curvature of 2.716 mm, the second lens (2) has an object-side radius of curvature of 7.675 mm, the second lens (2) has an image-side radius of curvature of -5.41 mm, the third lens (3) has an object-side vertex radius of curvature of -94.668 mm, the third lens (3) has an image-side vertex radius of curvature of -12.478 mm, the fourth lens (4) has an object-side vertex radius of curvature of -3.669 mm, the fourth lens (4) has an image-side vertex radius of curvature of 11.548 mm, the fifth lens (5) has an object-side vertex radius of curvature of 4.544 mm, and the fifth lens (5) has an image-side vertex radius of curvature of -6.399 mm.

5. The lens assembly according to claim 1, characterized in that, The aspherical parameters of the object side of the third lens (3) are: R=-94.668, K=-926.003, A2=0, A4=-0.011049742, A6=-0.0028379688, A8=0.00073168256, A10=-0.00022827222, A12=4.0905797e-05, A14=-3.0356861e-06; The aspherical parameters of the image side of the third lens (3) are: R=-12.478, K=10.044, A2=0, A4=-0.020352132, A6=0.003638839, A8=-0.0012961866, A10=3.553437e-05, A12=3.553437e-05, A14=-7.1446161e-06; The aspherical parameters of the object side of the fourth lens (4) are: R=-3.669, K=-5.837, A2=0, A4=0.0039305581, A6=0.0010338095, A8=-0.0006572453, A10=-7.1205873e-05, A12=5.8197923e-05, A14=-6.4668442e-06; The aspherical parameters of the image side of the fourth lens (4) are: R=11.548, K=-39.785, A2=0, A4=0.023370919, A6=-0.0044710717, A8=0.0007331783, A10=-6.8405182e-05, A12=-3.2780146e-06, A14=6.6690007e-07; The aspherical parameters of the object side of the fifth lens (5) are: R=4.544, K=-7.964, A2=0, A4=0.0056051473, A6=-0.00066757209, A8=-4.6359966e-06, A10=3.0313165e-05, A12=-5.4752154e-06, A14=1.6260105e-07; The aspherical parameters of the image side of the fifth lens (5) are: R=-6.399, K=0, A2=0, A4=0.0021911968, A6=-4.0829074e-05, A8=7.925455e-05, A10=-3.6963363e-05, A12=6.482164e-06, A14=-4.3105005e-07.

6. The lens assembly according to claim 1, characterized in that, The air gap between the first lens (1) and the second lens (2) is [4.983mm, 5.083mm], the air gap between the second lens (2) and the third lens (3) is [0.256mm, 0.356mm], the air gap between the third lens (3) and the fourth lens (4) is [0.063mm, 0.163mm], the air gap between the fourth lens (4) and the fifth lens (5) is [0.04mm, 0.14mm], and the air gap between the fifth lens (5) and the sixth lens (6) is [0.038mm, 0.138mm]; and / or The center thickness of the first lens (1) ranges from [0.7 mm to 0.9 mm], the center thickness of the second lens (2) ranges from [2.56 mm to 2.76 mm], the center thickness of the third lens (3) ranges from [0.98 mm to 1.18 mm], the center thickness of the fourth lens (4) ranges from [0.72 mm to 0.92 mm], the center thickness of the fifth lens (5) ranges from [1.646 mm to 1.846 mm], and the center thickness of the sixth lens (6) ranges from [0.90 mm to 1.10 mm].

7. The lens assembly according to claim 1, characterized in that, The air gap between the first lens (1) and the second lens (2) is 5.033 mm, the air gap between the second lens (2) and the third lens (3) is 0.306 mm, the air gap between the third lens (3) and the fourth lens (4) is 0.113 mm, the air gap between the fourth lens (4) and the fifth lens (5) is 0.09 mm, and the air gap between the fifth lens (5) and the sixth lens (6) is 0.088 mm; and / or The center thickness of the first lens (1) is 0.8 mm, the center thickness of the second lens (2) is 2.66 mm, the center thickness of the third lens (3) is 1.08 mm, the center thickness of the fourth lens (4) is 0.82 mm, the center thickness of the fifth lens (5) is 1.746 mm, and the center thickness of the sixth lens (6) is 1.00 mm.

8. The lens assembly according to claim 1, characterized in that, The refractive index of the first lens (1) is 1.59279±5%, the refractive index of the second lens (2) is 1.8348±5%, the refractive index of the third lens (3) is 1.53116±5%, the refractive index of the fourth lens (4) is 1.6613±5%, the refractive index of the fifth lens (5) is 1.53116±5%, and the refractive index of the sixth lens (6) is 1.5168±5%.

9. A shooting device, characterized in that, The shooting device includes a lens assembly as described in any one of claims 1 to 8.

10. A cooking device, characterized in that, The cooking equipment includes the imaging device as described in claim 9.

Images