An optical imaging lens, a photographic system and an electronic device

Abstract

The present application relates to a kind of optical imaging lens, photographic system and electronic device, optical imaging lens is successively included from object side to image side: first lens, diaphragm, second lens, third lens, fourth lens and filter, first lens, second lens, third lens and fourth lens surface have coating, coating is infrared coating or visible light antireflection film, optical imaging lens satisfies following relationship: f2>1, wherein, f2 is second lens focal length.The optical imaging lens of the present application adopts four-piece structure, each lens surface has the coating of infrared coating or visible light antireflection film, so that the optical imaging lens of the present application, different coating can be selected according to the different application scenarios of product, to adapt to different application requirements, so that optical imaging lens can be used day and night and does not affect imaging effect, effectively improve the versatility of the optical imaging lens of the present application, so that the shooting effect of the product applied is more stable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical imaging lenses, in particular to an optical imaging lens, a photographic system and an electronic device. BACKGROUND

[0002] In recent years, with the rise of smart home, general smart home appliances are equipped with cameras to realize various intelligent functions such as face recognition, gesture recognition and portrait tracking. However, the existing traditional camera can only meet the shooting requirements during the day. When the light is dim or at night, the shooting effect of the traditional camera is poor. Some smart home appliances also need to operate in an environment with poor light. Simply applying a traditional camera will affect the normal operation of the intelligent functions of the smart home appliance, thereby affecting the user experience.

[0003] Therefore, in order to make the shooting effect of the intelligent functions of the smart home appliance more stable and adapt to the use requirements of different light environments, there is an urgent need for an optical imaging lens that can be used day and night without affecting the imaging effect. SUMMARY

[0004] In order to solve at least one of the above technical problems, the present application provides an optical imaging lens that can adapt to the use requirements of different light environments, a photographic system and an electronic device.

[0005] The present application discloses an optical imaging lens, which comprises, in order from the object side to the image side:

[0006] a first lens having negative refractive power, the object side surface being convex at the vicinity of the optical axis and the image side surface being concave at the vicinity of the optical axis;

[0007] a second lens having positive refractive power, the image side surface being convex at the vicinity of the optical axis;

[0008] a third lens having positive refractive power, the object side surface being convex at the vicinity of the optical axis and the image side surface being convex at the vicinity of the optical axis; and

[0009] a fourth lens having positive refractive power, the object side surface being concave at the vicinity of the optical axis and the image side surface being convex at the vicinity of the optical axis;

[0010] The surfaces of the first lens, the second lens, the third lens and the fourth lens are provided with a coating layer, which is an infrared coating or a visible light anti-reflection coating.

[0011] The optical imaging lens satisfies the following relationship:

[0012] f2>1;

[0013] wherein f2 is the focal length of the second lens.

[0014] According to an embodiment of the present application, the optical imaging lens satisfies the following relationship:

[0015] 2.5 < CT3 / T34 < 5;

[0016] wherein CT2 is the maximum thickness of the second lens on the optical axis, and T34 is the maximum distance between the third lens and the fourth lens on the optical axis.

[0017] According to an embodiment of the present application, the optical imaging lens satisfies the following relationship:

[0018] -2 < f1 / f < 0;

[0019] 0 < f3 / f < 3;

[0020] 0 < f3 / f < 2; and

[0021] 0 < f4 / f < 1.5;

[0022] wherein 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, and f is the focal length of the imaging lens group.

[0023] According to an embodiment of the present application, the optical imaging lens satisfies the following relationship:

[0024] -1 < R32 / R31 < -0.4;

[0025] wherein R31 is the curvature of the object side surface of the third lens, and R32 is the curvature of the image side surface of the third lens.

[0026] According to an embodiment of the present application, the optical imaging lens satisfies the following relationship:

[0027] 0 < CT1 / TTL < 0.2; and

[0028] 0 < CT2 / TTL < 0.3;

[0029] wherein CT1 is the maximum thickness of the first lens on the optical axis, CT2 is the maximum thickness of the second lens on the optical axis, and TTL is the distance from the near axis of the object side surface of the first lens to the image plane.

[0030] According to an embodiment of the present application, the optical imaging lens satisfies the following relationship:

[0031] -3 < (R41+R42) / (R41-R42) < -1;

[0032] wherein R41 is the curvature of the object side surface of the fourth lens, and R42 is the curvature of the image side surface of the fourth lens.

[0033] According to an embodiment of the present application, the optical imaging lens satisfies the following relationship:

[0034] 0.1 < (CT3+CT4) / TTL < 1;

[0035] Wherein, CT3 is the maximum thickness of the third lens on the optical axis, CT4 is the maximum thickness of the fourth lens on the optical axis, and TTL is the distance from the first lens object side at the near axis to the imaging surface.

[0036] According to an embodiment of the present application, the optical imaging lens satisfies the following relationship:

[0037] 130 < FOV < 140;

[0038] Wherein, FOV is the field of view of the lens group.

[0039] The present application also discloses a camera system, comprising the optical imaging lens described above.

[0040] The present application also discloses an electronic device, comprising the optical imaging lens described above.

[0041] Compared with the prior art, the present application has the beneficial effects that: the optical imaging lens of the present application adopts a four-piece structure, the overall length of the optical imaging system is short, effectively adapting to the miniaturization design of the product, and through the matching of different refractive powers, the entire imaging lens has better light converging ability; the surfaces of each lens have an infrared coating or a visible light anti-reflection coating, so that the optical imaging lens of the present application can select different coatings according to different application scenarios of the product to adapt to different application requirements, so that the optical imaging lens can be used day and night without affecting the imaging effect, effectively improving the versatility of the optical imaging lens of the present application, and making the shooting effect of the applied product more stable. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 FIG. 1 is a structural schematic diagram of the optical imaging lens of Example 1.

[0043] Figure 2 FIG. 2 is an astigmatism and distortion curve diagram of the optical imaging lens of Example 1.

[0044] Figure 3 FIG. 3 is a spherical aberration curve diagram of the optical imaging lens of Example 1.

[0045] Figure 4 FIG. 4 is a structural schematic diagram of the optical imaging lens of Example 2.

[0046] Figure 5 FIG. 5 is an astigmatism and distortion curve diagram of the optical imaging lens of Example 2.

[0047] Figure 6 FIG. 6 is a spherical aberration curve diagram of the optical imaging lens of Example 2.

[0048] Figure 7Structure schematic view of the optical imaging lens in Example 3.

[0049] Figure 8 Astigmatism and distortion curve of the optical imaging lens in Example 3.

[0050] Figure 9 Coma curve of the optical imaging lens in Example 3.

[0051] Figure 10 Structure schematic view of the optical imaging lens in Example 4.

[0052] Figure 11 Astigmatism and distortion curve of the optical imaging lens in Example 4.

[0053] Figure 12 Coma curve of the optical imaging lens in Example 4.

[0054] Figure 13 Structure schematic view of the optical imaging lens in Example 5.

[0055] Figure 14 Astigmatism and distortion curve of the optical imaging lens in Example 5.

[0056] Figure 15 Coma curve of the optical imaging lens in Example 5. DETAILED DESCRIPTION

[0057] The present application is further described below in conjunction with the specific embodiments, wherein the accompanying drawings are only used for illustrative explanation, represent only schematic views, not physical views, and cannot be understood as limitation to the present patent. In order to better illustrate the specific embodiments of the present application, some components in the drawings are omitted, enlarged or reduced, and it is understood by those skilled in the art that some well-known structures and their descriptions can be omitted in the drawings. Based on the specific embodiments in the present application, all other specific embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0058] Please refer to Figure 1 as shown.

[0059] In the description of the present application, the object side refers to the side of the lens towards the object, the surface of the lens towards the object is the object side surface, the image side refers to the side of the lens towards the imaging surface, and the surface of the lens towards the imaging surface is the image side surface.

[0060] The convex lens object side of the present application refers to the fact that the surface of the lens object side is always on the right side of the tangent plane at any point on the surface, and the curvature radius is positive, and vice versa, the object side is concave, and the curvature radius is negative; the convex image side refers to the fact that the surface of the lens image side is always on the left side of the tangent plane at any point on the surface, and the curvature radius is negative, and vice versa, the image side is concave, and the curvature radius is positive; if the tangent plane is made at any point on the surface of the lens object side or image side, the surface has both the part on the left side of the tangent plane and the part on the right side of the tangent plane, then the surface has a curve inflection point, and the judgment of the concave-convex of the object side and the image side near the optical axis still applies to the above.

[0061] In addition, the aspheric surface curve equation of each lens is as follows:

[0062]

[0063] Wherein, Z is the distance vector height of the aspheric surface from the aspheric surface origin when the aspheric surface is in the position of height r along the optical axis direction; c is the near-axis curvature of the aspheric surface (the curvature radius R=1 / c, that is, the inverse of the curvature); k is the conic coefficient; Ai is the i-th order coefficient of the aspheric surface, and the high-order coefficients applied in the present application are A4, A6, A8, A10, A12, A14, A16, A18 and A20.

[0064] Please refer to Figure 1 .

[0065] The optical imaging lens of the present application sequentially comprises, from the object side to the image side: a first lens 1, a diaphragm 2, a second lens 3, a third lens 4, a fourth lens 5 and a filter 6, each lens has an object side surface facing the object side and an image side surface facing the image side, and the optical imaging lens further comprises an imaging surface 7 located on the image side.

[0066] The first lens 1 has a negative refractive power, the object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis; the second lens 3 has a positive refractive power, the object side surface is concave or convex at the near optical axis, and the image side surface is convex at the near optical axis; the third lens 4 has a positive refractive power, the object side surface is convex at the near optical axis, and the image side surface is convex at the near optical axis; the fourth lens 5 has a positive refractive power, the object side surface is concave at the near optical axis, and the image side surface is convex at the near optical axis. The above four lenses have a spacing distance between any adjacent lenses, and the lenses are relatively fixed and cannot move.

[0067] In the structure, the first lens 1 is configured with negative refractive power and the object side is convex at the near optical axis, which can effectively balance the low-order aberration; the second lens 3 has positive refractive power and the image side is convex at the near optical axis, which is beneficial to eliminate the aberration generated by the first lens 1; the third lens 4 has positive refractive power and the image side is convex at the near optical axis, which helps to make the principal point of the optical imaging system away from the image side end, thereby effectively shortening the overall length of the optical imaging system, which is beneficial to the miniaturization of the product; the fourth lens 5 has positive refractive power and the object side is convex at the near optical axis, which can effectively correct the near-axis spherical aberration, while reducing the peripheral astigmatism field curvature, thereby improving the overall imaging quality of the optical imaging system. By matching the refractive power between the above lenses, when certain conditions are met, the entire optical system has better light converging ability.

[0068] The coating layer of each lens surface has infrared coating or visible light anti-reflection coating, so that the optical imaging lens can be used day and night without affecting the imaging effect, effectively improving the versatility of the optical imaging lens, and making the shooting effect of the applied product more stable.

[0069] The optical imaging lens satisfies the relationship: f2>1, where f2 is the focal length of the second lens. By controlling the value of f2 to satisfy the above relationship, the optical imaging lens has good imaging level characteristics, thereby effectively ensuring the imaging quality of the optical imaging lens.

[0070] Further, the optical imaging lens satisfies the following relationship: 2.5<CT3 / T34<5, where CT2 is the maximum thickness of the second lens 3 on the optical axis, and T34 is the maximum distance between the third lens 4 and the fourth lens 5 on the optical axis. By controlling the ratio of CT3 / T34 to satisfy the above relationship, the thickness and spacing of the third lens 4 and the fourth lens 5 are effectively ensured to be within a reasonable range, thereby effectively reducing the overall assembly difficulty of the optical imaging lens, improving the assembly efficiency and assembly effect.

[0071] Further, the optical imaging lens satisfies the following relationship: -2<f1 / f≤0, 0<f3 / f<3, 0<f3 / f<2, and 0<f4 / f<1.5, where f1 is the focal length of the first lens 1, f2 is the focal length of the second lens 3, f3 is the focal length of the third lens 4, f4 is the focal length of the fourth lens 5, and f is the focal length of the imaging lens group. By controlling the above ratios to satisfy the above relationships, the optical sensitivity of the optical imaging lens is effectively reduced, and the overall imaging quality of the optical imaging system is improved, while the optical imaging lens has a shorter optical length, which is more suitable for the miniaturization design of the product.

[0072] Further, the optical imaging lens satisfies the following relationship: -1 < R32 / R31 < -0.4, wherein R31 is a curvature of a third lens 4 on a subject side, and R32 is a curvature of the third lens on an image side, the ratio of R32 / R31 is controlled to satisfy the above relationship, which effectively reduces the imaging chromatic aberration of the third lens 4, thereby effectively preventing the imaging from being purple or red, and ensuring the imaging quality.

[0073] Further, the optical imaging lens satisfies the following relationship: 0 < CT1 / TTL < 0.2, and 0 < CT2 / TTL < 0.3, wherein CT1 is a maximum thickness of the first lens 1 on the optical axis, CT2 is a maximum thickness of the second lens 3 on the optical axis, and TTL is a distance from a near axis of the subject side of the first lens to an image surface, the ratio of CT1 / TTL and CT2 / TTL is controlled to satisfy the above relationship, which makes the spacing between the lenses more reasonable, thereby effectively reducing the total length of the optical imaging lens, reducing the assembly difficulty of the optical imaging lens, and further improving the production efficiency of the enterprise.

[0074] Further, the optical imaging lens satisfies the following relationship: -3 < (R41+R42) / (R41-R42) < -1, wherein R41 is a curvature of a fourth lens on a subject side, and R42 is a curvature of the fourth lens on an image side, the ratio of (R41+R42) / (R41-R42) is controlled to satisfy the above relationship, which effectively reduces the stray light generated by the fourth lens, and further improves the imaging quality of the optical imaging lens.

[0075] Further, the optical imaging lens satisfies the following relationship: 0.1 < (CT3+CT4) / TTL < 1, wherein CT3 is a maximum thickness of the third lens on the optical axis, CT4 is a maximum thickness of the fourth lens on the optical axis, and TTL is a distance from a near axis of the subject side of the first lens to an image surface, the ratio of (CT3+CT4) / TTL is controlled to satisfy the above relationship, which effectively and reasonably distributes the spacing between the third lens and the fourth lens, thereby making the optical imaging lens have a better optical imaging effect.

[0076] Still further, the optical imaging lens satisfies the following relationship: 130 < FOV < 140, wherein FOV is a field of view of a lens group, the value of FOV is controlled to satisfy the above relationship, which makes the optical imaging lens have a good field of view, and greatly improves the wide-angle effect of the optical imaging lens when imaging.

[0077] The application further discloses a camera system, which comprises the optical imaging lens described above, and the camera system can be applied to various electronic devices or processing equipment.

[0078] The application further discloses an electronic device comprising the optical imaging lens, and the electronic device comprises a digital camera, a tablet computer, a smart television, a network monitoring device, a smart refrigerator, a smart range hood, a driving recorder, a reversing device and a wearable device.

[0079] When the optical imaging lens of the application is imaging, light enters from the object side of the wide-angle imaging lens and sequentially passes through the first lens 1, the diaphragm 2, the second lens 3, the third lens 4, the fourth lens 5 and the filter 6 to form an image on the imaging surface 7.

[0080] In the application, the object side and the image side of the first lens 1, the second lens 3, the third lens 4 and the fourth lens 5 are all aspherical structures, the aspherical structure is light, thin and flat, so that the optical imaging lens of the application is light and thin, and the image is clearer than the spherical structure.

[0081] The optical imaging lens of the application will be described in detail in combination with the following specific embodiments and the drawings.

[0082] Embodiment 1

[0083] Please refer to Table 1-1, Table 1-2 and Table 1-3 in the optical imaging lens of Embodiment 1. Figures 1 to 3

[0084] Table 1-1 is the basic parameters of the optical imaging lens of the embodiment:

[0085] Table 1-2 is the aspherical coefficients of each lens in the embodiment:

[0086] Table 1-3 is the values of each condition expression in the embodiment:

[0087] Embodiment 1

[0088] Please refer to Table 1-1, Table 1-2 and Table 1-3 in the optical imaging lens of Embodiment 1. Figures 1 to 3

[0089] Table 1-1 is the basic parameters of the optical imaging lens of the embodiment:

[0090]

[0091] Table 1-2 is the aspherical coefficients of each lens in the embodiment:

[0092]

[0093] Table 1-3 is the values of each condition expression in the embodiment: ​​

[0094]

[0095] Embodiment 2

[0096] Please refer to Figures 4 to 6 As shown in Table 2-1, Table 2-2 and Table 2-3, the optical imaging lens in Embodiment 2 meets the requirements.

[0097] Table 2-1 is the basic parameters of the optical imaging lens in this embodiment:

[0098]

[0099]

[0100] Table 2-2 is the aspherical surface coefficients of each lens in this embodiment:

[0101]

[0102] Table 2-3 is the values of each conditional expression in this embodiment:

[0103]

[0104] Embodiment 3

[0105] Please refer to Figures 7 to 9 As shown in Table 3-1, Table 3-2 and Table 3-3, the optical imaging lens in Embodiment 3 meets the requirements.

[0106] Table 3-1 is the basic parameters of the optical imaging lens in this embodiment:

[0107]

[0108] Table 3-2 is the aspherical surface coefficients of each lens in this embodiment:

[0109]

[0110] Table 3-3 is the values of each conditional expression in this embodiment:

[0111]

[0112]

[0113] Embodiment 4

[0114] Please refer to Figures 10 to 12 As shown in Table 4-1, Table 4-2 and Table 4-3, the optical imaging lens in Embodiment 4 meets the requirements.

[0115] Table 4-1 is the basic parameters of the optical imaging lens in this embodiment:

[0116]

[0117] Table 4-2 is the aspherical surface coefficients of each lens in this embodiment:

[0118]

[0119]

[0120] Table 4-3 is the values of each conditional expression in this embodiment:

[0121]

[0122] Embodiment 5

[0123] Please refer to Figures 13 to 15 The optical imaging lens in Embodiment 5 meets Table 5-1, Table 5-2 and Table 5-3.

[0124] Table 5-1 is the basic parameters of the optical imaging lens in this embodiment:

[0125]

[0126] Table 5-2 is the aspherical surface coefficients of each lens in this embodiment:

[0127]

[0128]

[0129] Table 5-3 is the values of each conditional expression in this embodiment:

[0130]

[0131] In order to facilitate the comparison of the above five embodiments, the following table is a summary of the values obtained by each expression under the corresponding conditions of each embodiment:

[0132]

[0133]

[0134] In summary, the optical imaging lens of the present application adopts a four-piece structure, the overall length of the optical imaging system is short, effectively adapting to the miniaturization design of the product, and through the matching of different refractive powers, the entire imaging lens has better light converging ability; each lens surface has an infrared coating or a visible light anti-reflection coating, so that the optical imaging lens of the present application can select different coatings according to different application scenarios of the product to adapt to different application requirements, so that the optical imaging lens can be used day and night without affecting the imaging effect, effectively improving the versatility of the optical imaging lens of the present application, and making the shooting effect of the applied product more stable.

[0135] In the description of the application, it should be understood that the terms such as "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0136] In addition, the terms "first", "second", "third", etc. are only used for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0137] Although the description of the application is made in combination with the above specific embodiments, it is obvious that many substitutions, modifications and changes can be made by those skilled in the art according to the above content. Therefore, all such alternatives, improvements and changes are included in the spirit and scope of the application.

Claims

1. An optical imaging lens, characterized in that, Consisting of a first lens, a second lens, a third lens, and a fourth lens, from the object side to the image side in order are: A first lens with negative refractive power, the object side surface is convex at the near optical axis, the image side surface is concave at the near optical axis; A second lens with positive refractive power, the image side surface is convex at the near optical axis; A third lens with positive refractive power, the object side surface is convex at the near optical axis, the image side surface is convex at the near optical axis; And A fourth lens with positive refractive power, the object side surface is concave at the near optical axis, the image side surface is convex at the near optical axis; The first lens, the second lens, the third lens and the fourth lens surface have a coating, the coating is infrared coating or visible light anti-reflection film; The optical imaging lens satisfies the relationship: 1.682＜f2＜2.226； 2.5 < CT3 / T34 < 5; -2 < f1 / f ≤ 0; 0 < f3 / f < 2; And 0 < f4 / f < 1.5; Wherein, f2 is the focal length of the second lens; CT2 is the maximum thickness of the second lens on the optical axis, T34 is the maximum distance of the third lens and the fourth lens on the optical axis; 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, and f is the focal length of the imaging lens group. 2.The optical imaging lens according to claim 1, wherein, The optical imaging lens satisfies the following relationship: -1 < R32 / R31 < -0.4; Wherein, R31 is the curvature of the object side surface of the third lens, and R32 is the curvature of the image side surface of the fifth lens. 3.The optical imaging lens according to claim 1, wherein, The optical imaging lens satisfies the following relationship: 0 < CT1 / TTL < 0.2; And 0 < CT2 / TTL < 0.3; Wherein, CT1 is the maximum thickness of the first lens on the optical axis, CT2 is the maximum thickness of the second lens on the optical axis, and TTL is the distance from the object side surface of the first lens to the image surface at the near axis. 4.The optical imaging lens according to claim 1, wherein, The optical imaging lens satisfies the following relationship: -3 < (R41+R42) / (R41-R42) < -1; Wherein, R41 is the curvature of the object side surface of the fourth lens, and R42 is the curvature of the image side surface of the fourth lens.

5. The optical imaging lens according to claim 1, characterized in that, The optical imaging lens satisfies the following relationship: 0.1 < (CT3+CT4) / TTL < 1; Wherein, CT3 is the maximum thickness of the third lens on the optical axis, CT4 is the maximum thickness of the fourth lens on the optical axis, and TTL is the distance from the object side surface of the first lens to the imaging surface at the near axis. 6.The optical imaging lens according to claim 1, wherein, The optical imaging lens satisfies the following relationship: 130 < FOV < 140; Wherein, FOV is the field of view of the lens group.

7. An image pickup system characterized by comprising: Comprising: The optical imaging lens of any one of claims 1 to 6.

8. An electronic device, comprising: Comprising: The optical imaging lens of any one of claims 1 to 6.

Images