Day and night confocal super wide-angle doorbell lens optical system

Abstract

The utility model discloses a kind of day and night confocal super wide-angle doorbell lens optical systems, it is along optical axis from object plane to image plane sequentially includes: first lens, second lens, third lens, diaphragm, fourth lens, fifth lens, sixth lens, optical filter, protective glass and image plane;Wherein fourth lens and fifth lens form a group of cemented lens.The maximum field angle of this kind of day and night confocal super wide-angle doorbell lens optical system can reach 210 °, can substantially widen visual range, the entrance and surrounding larger area are included in monitoring field of view, reduce visual blind area;Support 800W pixel, can provide high-definition image, so that the figure in picture, object details are clear and discernible;Day and night confocal design realizes 24 hours uninterrupted safety monitoring, provides all-round guarantee for family safety.

Description

Technical Field

[0001] This utility model relates to the technical field of intelligent doorbell imaging devices, specifically, to an optical system for a day and night confocal ultra-wide-angle doorbell lens. Background Technology

[0002] In recent years, with the rapid development of smart technology, smart doorbells are gradually replacing traditional doorbells. Compared with traditional doorbells, the visual function of smart doorbells has completely changed the way visitors communicate and home security is handled. Traditional doorbells are limited to simply ringing to alert people to a visitor. After hearing the bell, the homeowner has to go to the door and ask the visitor's identity through the door, which is both time-consuming and poses certain security risks. If they encounter someone with ill intentions, opening the door rashly could put them in danger. Smart doorbells, on the other hand, are completely different. They are equipped with high-definition cameras and displays, building a visual defense line at the doorstep. When a visitor presses the doorbell, the homeowner, even if they are thousands of miles away, can receive an immediate notification via a mobile app and then view the live image outside the door, clearly seeing the visitor's face, clothing, and even the surrounding environment. With its unique visual function, smart doorbells bring a brand-new experience to home life and are bound to become a standard feature in every household in the future, leading a new revolution in home security.

[0003] However, current smart doorbell cameras often suffer from problems such as a narrow angle that fails to fully cover the doorway area, resulting in blind spots; unclear images with severe purple fringing, making it difficult to display image details and affecting user experience; and lack of focus day and night, making it difficult to monitor the outside scene effectively at night. Utility Model Content

[0004] This invention proposes an optical system for a day and night co-focus ultra-wide-angle doorbell lens. This optical system features ultra-wide-angle, ultra-high-definition imaging, purple fringing optimization, no pyrolysis, low cost, and day and night co-focus.

[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a day and night confocal ultra-wide-angle doorbell lens optical system, which includes, along the optical axis from the object plane to the image plane, the following components in sequence: a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, a sixth lens, a filter, a protective glass, and an image plane;

[0006] The first lens has a convex surface on the object side and a concave surface on the image side;

[0007] The second lens has a convex surface on the object side and a concave surface on the image side;

[0008] The third lens has a convex surface on both the object plane and the image plane sides;

[0009] The fourth lens has a concave object plane and a concave image plane.

[0010] The fifth lens has a convex surface on both the object plane and the image plane sides;

[0011] The object plane side of the sixth lens is convex, and the image plane side is also convex.

[0012] The fourth and fifth lenses form a set of cemented lenses;

[0013] And it satisfies the following relationship:

[0014] 6.6<|f1 / f|<7.3; 3.5<|f2 / f|<4.4; 3.4<|f3 / f|<4.2; 8.2<|f4 / f|<9.3; 38.6<|f5 / f|<39.9; 5.3<|f6 / f|<6.3;

[0015] Where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f is the effective focal length of the entire optical system.

[0016] In some embodiments, the Abbe constant Vd2 of the second lens, the Abbe constant Vd4 of the fourth lens, the Abbe constant Vd5 of the fifth lens, and the Abbe constant Vd6 of the sixth lens are all greater than 50 and less than 58.

[0017] In some embodiments, the refractive indices of the individual lenses in the optical system satisfy the following condition:

[0018] 1.78<Nd1<1.95; 1.48<Nd2<1.59; 1.92<Nd3<2.03; 1.65<Nd4<1.76; 1.51<Nd5<1.68; 1.51<Nd6<1.68;

[0019] Wherein, Nd1 is the refractive index of the first lens, Nd2 is the refractive index of the second lens, Nd3 is the refractive index of the third lens, Nd4 is the refractive index of the fourth lens, Nd5 is the refractive index of the fifth lens, and Nd6 is the refractive index of the sixth lens.

[0020] In some embodiments, the maximum field of view (FOV) of the optical system satisfies the following condition:

[0021] FOV ≥ 210°.

[0022] In some embodiments, the aperture of the optical system satisfies the following condition:

[0023] F / NO = 2.0.

[0024] In some embodiments, the effective focal length f of the optical system satisfies the following condition:

[0025] 1.0mm≤f≤1.16mm.

[0026] In some embodiments, the first lens is meniscus-shaped and has a negative optical power;

[0027] The second lens is concave-convex, with the object side being convex and the image side being concave, and its optical power is negative.

[0028] The third lens is biconvex, with a large convex surface on the object side and a small convex surface on the image side, and its optical power is positive.

[0029] The fourth lens is biconcave, with a small concave surface on the object side and a large concave surface on the image side, and its optical power is negative.

[0030] The fifth lens is biconvex, with a convex surface on the object side and a convex surface on the image side, and its optical power is negative.

[0031] The sixth lens is biconvex, with a small convex surface on the object side and a large convex surface on the image side, and its optical power is positive.

[0032] In some embodiments, the aperture stop is disposed between the third lens and the fourth lens.

[0033] In summary, this utility model has the following beneficial effects:

[0034] This utility model has an ultra-wide field of view (FOV) of ≥210°, which can significantly expand the visible range, bringing the entrance and surrounding area into the monitoring field of view, reducing blind spots, and allowing users to have a comprehensive understanding of the entrance situation whether on a mobile phone or an indoor display screen. Visitors, deliverymen, and passersby near the entrance can all be clearly seen, effectively improving security monitoring capabilities.

[0035] This invention features excellent day and night confocal focusing capabilities, ensuring clear images under various lighting conditions, including at night. In bright daylight, it produces vibrant colors and rich details; at night or in low-light environments, infrared supplementary lighting technology ensures clear images of the doorway without blurring or dimness, providing 24 / 7 uninterrupted security monitoring and comprehensive protection for home safety.

[0036] This utility model's lens assembly employs a multi-element plastic aspherical lens design. Through proper arrangement, it reduces chromatic aberration at the image edges, particularly purple fringing, resulting in better imaging of the smart doorbell system. This allows it to support 8MP resolution, providing high-definition images where details of people and objects are clearly discernible. Users can accurately identify visitors' facial features, clothing, and information from delivery packages, helping to confirm visitor identity, avoid misjudgments, and better record events at the door, providing clear evidence for potential disputes or security issues.

[0037] This invention can maintain stable imaging without refocusing when there are large temperature changes, and the image quality will not degrade due to temperature changes.

[0038] This utility model adopts a 2G+4P structural design, which is designed in a cost-effective way to reduce the cost of the product. Attached Figure Description

[0039] Figure 1 A schematic diagram of the optical system provided in an embodiment of this utility model;

[0040] Figure 2 MTF resolution diagram of the optical system provided in the embodiments of this utility model in visible light;

[0041] Figure 3 Defocus curve of the optical system provided in this embodiment of the present invention at 20°C in visible light;

[0042] Figure 4 Defocus curve of the optical system provided in this embodiment of the present invention at -40°C in visible light;

[0043] Figure 5 Defocus curve of the optical system provided in this embodiment of the present invention at 95°C in visible light;

[0044] Figure 6 MTF analysis diagram of the optical system provided in this embodiment of the present invention at 850nm infrared light;

[0045] Figure 7 The defocus curve of the optical system provided in this embodiment of the present invention at 850nm infrared light;

[0046] Figure 8 A relative illumination diagram of the optical system provided in this embodiment of the utility model;

[0047] Figure 9 F-THETA distortion diagram of the optical system provided in the embodiment of this utility model;

[0048] Figure 10A vertical axis color difference diagram provided for an embodiment of this utility model. Detailed Implementation

[0049] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0050] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0052] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0053] like Figure 1 As shown, this embodiment provides an optical system for a day and night confocal ultra-wide-angle doorbell lens, which includes, in sequence along the optical axis from the object plane to the image plane: a first lens E1, a second lens E2, a third lens E3, an aperture stop STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a filter IR, a protective glass CG, and an image plane IMA.

[0054] The object plane side S1 of the first lens E1 is convex, and the image plane side S2 is concave.

[0055] The object plane side S3 of the second lens E2 is convex, and the image plane side S4 is concave.

[0056] The object plane side S5 of the third lens E3 is convex, and the image plane side S6 is convex.

[0057] The object plane side S8 of the fourth lens E4 is concave, and the image plane side S9 is concave.

[0058] The object plane side S9 of the fifth lens E5 is convex, and the image plane side S10 is convex.

[0059] The object plane side S11 of the sixth lens E6 is convex, and the image plane side S12 is convex.

[0060] The fourth lens E4 and the fifth lens E5 form a set of cemented lenses;

[0061] And it satisfies the following relationship:

[0062] 6.6<|f1 / f|<7.3; 3.5<|f2 / f|<4.4; 3.4<|f3 / f|<4.2; 8.2<|f4 / f|<9.3; 38.6<|f5 / f|<39.9; 5.3<|f6 / f|<6.3;

[0063] Where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f is the effective focal length of the entire optical system.

[0064] As an improvement, the Abbe constants Vd2 of the second lens, Vd4 of the fourth lens, Vd5 of the fifth lens, and Vd6 of the sixth lens are all greater than 50 and less than 58.

[0065] As an improvement, the refractive indices of each lens in the optical system satisfy the following condition:

[0066] 1.78<Nd1<1.95; 1.48<Nd2<1.59; 1.92<Nd3<2.03; 1.65<Nd4<1.76; 1.51<Nd5<1.68; 1.51<Nd6<1.68;

[0067] Wherein, Nd1 is the refractive index of the first lens, Nd2 is the refractive index of the second lens, Nd3 is the refractive index of the third lens, Nd4 is the refractive index of the fourth lens, Nd5 is the refractive index of the fifth lens, and Nd6 is the refractive index of the sixth lens.

[0068] As an improvement, the maximum field of view (FOV) of the optical system satisfies the following condition:

[0069] FOV ≥ 210°.

[0070] As an improvement, the aperture of the optical system satisfies the following condition:

[0071] F / NO=2.0.

[0072] As an improvement, the effective focal length f of the optical system satisfies the following condition:

[0073] 1.0mm≤f≤1.16mm.

[0074] As an improvement, the first lens is meniscus-shaped and has a negative optical power;

[0075] The second lens is concave-convex, with the object side being convex and the image side being concave, and its optical power is negative.

[0076] The third lens is biconvex, with a large convex surface on the object side and a small convex surface on the image side, and its optical power is positive.

[0077] The fourth lens is biconcave, with a small concave surface on the object side and a large concave surface on the image side, and its optical power is negative.

[0078] The fifth lens is biconvex, with a convex surface on the object side and a convex surface on the image side, and its optical power is negative.

[0079] The sixth lens is biconvex, with a small convex surface on the object side and a large convex surface on the image side, and its optical power is positive.

[0080] As an improvement, the aperture ST0 is positioned between the third lens E3 and the fourth lens E4.

[0081] In this patent embodiment, when the working distance is infinity, the total focal length of the optical system (optical lens) is f=1.1mm, F / NO=2.0, and the maximum field of view (FOV) is 210°.

[0082] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

[0083] The parameters of each lens in this embodiment are listed in Table 1 below, and the aspherical coefficients of the lenses are shown in Table 2 below.

[0084] Table 1 Physical parameters of each lens

[0085]

[0086] Table 2 Aspherical coefficients of lenses

[0087]

[0088]

[0089] The aspherical coefficients satisfy the following equation:

[0090]

[0091] Where z is the aspherical sagitta, c is the paraxial curvature of the aspherical surface, the curvature is the reciprocal of the radius of curvature, y is the lens aperture, k is the conic coefficient, a4 is the 4th order aspherical coefficient, a6 is the 6th order aspherical coefficient, a8 is the 8th order aspherical coefficient, a10 is the 10th order aspherical coefficient, and a12 is the 12th order aspherical coefficient.

[0092] Specifically, in this embodiment, the R-value (radius of curvature), thickness, refractive index, Abbe number (ABB), and focal length (EFL-E) of each lens surface are shown in Table 1, and the aspherical parameters are shown in Table 2. In Table 1, Surf represents the mirror surface number, and INFINITY represents infinity. In Table 2, R1 represents the radius of curvature of the corresponding lens surface facing the object side, and R2 represents the radius of curvature of the corresponding lens surface facing the image side. A positive radius of curvature indicates that the mirror is curved towards the object side, and a negative radius of curvature indicates that the mirror is curved towards the image side. Mirror numbers 1 and 2 represent the two mirrors of the first lens E1 along the direction of light incidence, respectively; mirror numbers 3 and 4 represent the two mirrors of the second lens E2 along the direction of light incidence, respectively; mirror numbers 5 and 6 represent the two mirrors of the third lens E3 along the direction of light incidence, respectively; mirror number 8 represents the object-side mirror of the fourth lens E4; mirror number 9 represents the cemented surface of the fourth lens E4 and the fifth lens E5; mirror number 10 represents the image-side mirror of the fifth lens E5; and mirror numbers 11 and 12 represent the two mirrors of the sixth lens E6 along the direction of light incidence, respectively.

[0093] In this embodiment of the utility model, Figure 2 The modulation transfer function (MTF) curve, representing the visible light band, indicates the overall resolving power of an optical system. The horizontal axis represents spatial frequency (lp / mm), and the vertical axis represents the MTF value. The MTF value is used to evaluate the image quality of a lens, ranging from 0 to 1. It is worth noting that the optical transfer function is a relatively accurate, intuitive, and common way to evaluate the image quality of an optical system; a higher and smoother curve indicates better image quality and a stronger ability to reproduce the true image. Figure 2 It can be seen that in the visible light band, at a spatial frequency of 63 lp / mm, the MTF in the imaging region near the center is >0.8, indicating good imaging quality. Figure 3 This is represented as a defocus curve at 20°C in the visible light band. Figure 3It can be seen that the lens has good MTF concentration, making focusing easy, and the defocus curve trend is consistent across different field of view angles. From Figure 4 and Figure 5 It can be seen that the defocus curves at both low temperatures (-40℃) and high temperatures (95℃) meet the requirements for high resolution, with small focal point changes and stable thermal drift effects; from Figure 6 and Figure 7 It can be seen that the lens meets the requirements for high resolution in both the defocus curve and MTF in the infrared 850nm band, with an infrared defocus amount of 9um, and has good day and night confocal function, enabling clear imaging even at night. Figure 8 This is represented as a relative illumination diagram; the higher the relative illumination, the higher the overall brightness of the captured image. Figure 9 To represent it as an F-THETA distortion map, the smaller the F-THETA distortion, the less the compression at the edges of the image. Figure 10 Represented as a vertical axis chromatic aberration diagram, the smaller the vertical axis chromatic aberration, the better the color reproduction of the image and the better the purple fringing optimization.

Claims

1. An optical system for a day and night confocal ultra-wide-angle doorbell lens, characterized in that: Along the optical axis from the object plane to the image plane, the components are as follows: first lens, second lens, third lens, aperture stop, fourth lens, fifth lens, sixth lens, filter, protective glass, and image plane. The first lens has a convex surface on the object side and a concave surface on the image side; The second lens has a convex surface on the object side and a concave surface on the image side; The third lens has a convex surface on both the object plane and the image plane sides; The fourth lens has a concave object plane and a concave image plane. The fifth lens has a convex surface on both the object plane and the image plane sides; The object plane side of the sixth lens is convex, and the image plane side is also convex. The fourth and fifth lenses form a set of cemented lenses; And it satisfies the following relationship: 6.6<|f1 / f|<7.3; 3.5<|f2 / f|<4.4; 3.4<|f3 / f|<4.2; 8.2<|f4 / f|<9.3; 38.6<|f5 / f|<39.9; 5.3<|f6 / f|<6.3; Where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f is the effective focal length of the entire optical system.

2. The day and night confocal ultra-wide-angle doorbell lens optical system according to claim 1, characterized in that: The Abbe constants Vd2 of the second lens, Vd4 of the fourth lens, Vd5 of the fifth lens, and Vd6 of the sixth lens are all greater than 50 and less than 58.

3. The day and night confocal ultra-wide-angle doorbell lens optical system according to claim 1, characterized in that: The refractive indices of all lenses in the optical system satisfy the following condition: 1.78<Nd1<1.95; 1.48<Nd2<1.59; 1.92<Nd3<2.03; 1.65<Nd4<1.76; 1.51<Nd5<1.68; 1.51<Nd6<1.68; Wherein, Nd1 is the refractive index of the first lens, Nd2 is the refractive index of the second lens, Nd3 is the refractive index of the third lens, Nd4 is the refractive index of the fourth lens, Nd5 is the refractive index of the fifth lens, and Nd6 is the refractive index of the sixth lens.

4. The day and night confocal ultra-wide-angle doorbell lens optical system according to claim 1, characterized in that: The maximum field of view (FOV) of the optical system satisfies the following condition: FOV ≥ 210°.

5. The day and night confocal ultra-wide-angle doorbell lens optical system according to claim 1, characterized in that: The aperture of the optical system satisfies the following condition: F / NO = 2.

0.

6. The day and night confocal ultra-wide-angle doorbell lens optical system according to claim 1, characterized in that: The effective focal length f of the optical system satisfies the following condition: 1.0mm≤f≤1.16mm.

7. The day and night confocal ultra-wide-angle doorbell lens optical system according to claim 1, characterized in that: The first lens is meniscus-shaped and has a negative optical power. The second lens is concave-convex, with the object side being convex and the image side being concave, and its optical power is negative. The third lens is biconvex, with a large convex surface on the object side and a small convex surface on the image side, and its optical power is positive. The fourth lens is biconcave, with a small concave surface on the object side and a large concave surface on the image side, and its optical power is negative. The fifth lens is biconvex, with a convex surface on the object side and a convex surface on the image side, and its optical power is negative. The sixth lens is biconvex, with a small convex surface on the object side and a large convex surface on the image side, and its optical power is positive.

8. The day and night confocal ultra-wide-angle doorbell lens optical system according to claim 1, characterized in that: The aperture stop is positioned between the third lens and the fourth lens.

Images