A 5P small distortion imaging lens, a photographic imaging system and a smart terminal

Abstract

The present invention relates to a 5P small distortion imaging lens, which comprises a first lens, an aperture stop, a second lens, a third lens, a fourth lens and a fifth lens which are arranged in sequence from the object side to the image side along the optical axis; the first lens is a negative lens, the second lens is a positive lens, the third lens is a negative lens, the fourth lens is a positive lens, and the fifth lens is a negative lens; the object side surface of the first lens is a concave surface near the optical axis, and the image side surface is a concave surface near the optical axis; the object side surface of the second lens is a convex surface near the optical axis, and the image side surface is a convex surface near the optical axis; the object side surface of the third lens is a convex surface near the optical axis, and the image side surface is a concave surface near the optical axis; the object side surface of the fourth lens is a concave surface near the optical axis, and the image side surface is a convex surface near the optical axis; the object side surface of the fifth lens is a convex surface near the optical axis, and the image side surface is a concave surface near the optical axis. Under the premise of meeting high-definition imaging and small distortion, when matched with a new design architecture and a new film system, the lens has a light volume and excellent mass production performance.

Description

Technical Field

[0001] The present invention relates to the technical field of lens structure design, and in particular to a 5P small distortion imaging lens, a photographic imaging system and a smart terminal. Background Art

[0002] The 5G era has led to the rapid development of video call technology, and the demand for imaging lenses has gradually increased. The camera of a mobile phone is required to have high imaging performance and good adaptability to the environment. After all, most mobile phones are used outdoors, and the camera must adapt to the surrounding light, humidity, and temperature in various environments, and keep the picture clear and consistent with the real picture. The camera appeared as an accessory product of the mobile phone. It mainly pursues excellent image quality, and it must be lightweight, diverse in functions, personalized in appearance and low in price.

[0003] Therefore, it is necessary to supplement a new lens structure that can reduce the distortion of the imaging lens, lower the cost, and keep other performance unchanged or even better. Summary of the invention

[0004] Based on the above description, the present invention provides a method for reducing the distortion of an imaging lens, reducing the distortion of an imaging lens, and lowering the cost, while keeping other performances unchanged or even better.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] A 5P small distortion imaging lens, comprising a first lens, an aperture stop, a second lens, a third lens, a fourth lens and a fifth lens arranged in sequence from the object side to the image side along an optical axis;

[0007] The first lens is a negative lens, the second lens is a positive lens, the third lens is a negative lens, the fourth lens is a positive lens, and the fifth lens is a negative lens;

[0008] The object side surface of the first lens is concave at the near optical axis, and the image side surface is concave at the near optical axis; the object side surface of the second lens is convex at the near optical axis, and the image side surface is convex at the near optical axis; the object side surface of the third lens is convex at the near optical axis, and the image side surface is concave at the near optical axis; the object side surface of the fourth lens is concave at the near optical axis, and the image side surface is convex at the near optical axis; the object side surface of the fifth lens is convex at the near optical axis, and the image side surface is concave at the near optical axis; the focal length of the second lens is f2, the combined focal length of the second lens and the third lens is f23, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the core thickness of the fourth lens is T4, the focal length of the 5P small distortion imaging lens is f, and the following conditions are met: 1.293<f23 / f2<1.451; -3.384 <f3 / f<-2.625;0.686<f4 / f<0.836;-1.291<f5 / f<-0.836;0.554<T4 / f<0.602。

[0009] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0010] The 5P small distortion imaging lens provided in this application has a lens composition arrangement structure of -, +, -, +, -, which effectively reduces distortion. Through the reasonable adjustment and design of the focal length, while meeting the requirements of high-definition imaging and small distortion, it reduces component costs and assembly costs, improves production efficiency, and has lower lens material costs. When combined with a new design architecture and a new film system, it is lightweight and has excellent mass producibility.

[0011] The present application also provides a photographic imaging system, which includes the 5P small distortion imaging lens as described above.

[0012] The present application also provides an intelligent terminal, which includes the photographic imaging system as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of a 5P small distortion imaging lens disclosed in the present invention;

[0014] Figure 2 A schematic diagram of the structure of a 5P small distortion imaging lens proposed in the first embodiment of the application;

[0015] Figure 3 This is the RAY FAN diagram of Example 1 of the present application;

[0016] Figure 4 Schematic diagram of the distortion and field curvature of light at any pupil in Example 1 of the present application;

[0017] Figure 5 This is a schematic diagram of MFT performance of defocus change at a specified frequency in Example 1 of the present application;

[0018] Figure 6 A schematic diagram of the structure of a 5P small distortion imaging lens proposed in the second embodiment of the application;

[0019] Figure 7 This is the RAY FAN diagram of the second embodiment of the present application;

[0020] Figure 8 Schematic diagram of the distortion and field curvature of light at any pupil in the second embodiment of the present application;

[0021] Fig. 9 This is a schematic diagram of MFT performance of defocus change at a specified frequency in Example 2 of the present application;

[0022] Fig.10 This is a schematic diagram of the structure of a 5P small distortion imaging lens proposed in the third embodiment of the application;

[0023] Fig.11 This is the RAY FAN diagram of the third embodiment of the present application;

[0024] Fig.12 Schematic diagram of the distortion and field curvature of light at any pupil in the third embodiment of the present application;

[0025] Fig.13 This is a schematic diagram of MFT performance of defocus change at a specified frequency in Example 3 of the present application;

[0026] Fig.14 This is a schematic diagram of the structure of a 5P small distortion imaging lens proposed in the fourth embodiment of the application;

[0027] Fig.15 This is the RAY FAN diagram of the fourth embodiment of the present application;

[0028] Fig.16 Schematic diagram of the distortion and field curvature of light at any pupil in the fourth embodiment of the present application;

[0029] Fig.17 This is a schematic diagram of MFT performance of defocus change at a specified frequency in Example 4 of the present application;

[0030] Fig.18 This is a schematic diagram of the structure of a 5P small distortion imaging lens proposed in the fifth embodiment of the application;

[0031] Fig.19 This is the RAY FAN diagram of the fifth embodiment of the present application;

[0032] Fig. 20 Schematic diagram of the distortion and field curvature of light at any pupil in Example 5 of the present application;

[0033] Fig.21This is a schematic diagram of MFT performance of defocus change at a specified frequency in Example 5 of the present application;

[0034] In the figure:

[0035] L1, first lens, STO, aperture stop, L2, second lens, L3, third lens, L4, fourth lens, L5, fifth lens. DETAILED DESCRIPTION

[0036] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0038] It will be appreciated that spatial relationship terms such as "under", "beneath", "below", "under", "above", "above", etc., may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It will be appreciated that, in addition to the orientations shown in the figures, spatial relationship terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as "on" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90° or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0039] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. The "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0040] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0041] like Figure 1 As shown, a 5P small distortion imaging lens provided in an embodiment of the present application includes a first lens L1, an aperture stop STO, a second lens L2, a third lens L3, a fourth lens L4 and a fifth lens L5 arranged in sequence from the object side to the image side along the optical axis.

[0042] The first lens L1 is a negative lens, the second lens L2 is a positive lens, the third lens L3 is a negative lens, the fourth lens L4 is a positive lens, and the fifth lens L5 is a negative lens;

[0043] Among them, the object side surface of the first lens L1 is concave at the near optical axis, and the image side surface is concave at the near optical axis; the object side surface of the second lens L2 is convex at the near optical axis, and the image side surface is convex at the near optical axis; the object side surface of the third lens L3 is convex at the near optical axis, and the image side surface is concave at the near optical axis; the object side surface of the fourth lens L4 is concave at the near optical axis, and the image side surface is convex at the near optical axis; the object side surface of the fifth lens L5 is convex at the near optical axis, and the image side surface is concave at the near optical axis.

[0044] The focal length of the second lens L2 is specified to be f2, the combined focal length of the second lens L2 and the third lens L3 is f23, the focal length of the third lens L3 is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the center thickness of the second lens L2 is T4, the focal length of the 5P small distortion imaging lens is f, the center thickness of the fourth lens is T4, and the following conditions are met: 1.293<f23 / f2<1.451; -3.384 <f3 / f<-2.625;0.686<f4 / f<0.836;-1.291<f5 / f<-0.836;0.554<T4 / f<0.602。

[0045] The above technical solution of the present application is described in detail below using multiple embodiments.

[0046] Embodiment 1

[0047] The first embodiment has a structure as follows Figure 2As shown, the L1S1 surface and the L1S2 surface form the first lens L1, the L2S1 surface and the L2S2 surface form the second lens L2, the L3S1 surface and the L3S2 surface form the third lens L3, the L4S1 surface and the L4S2 surface form the fourth lens L4, and the L5S1 surface and the L5S2 surface form the fifth lens L5. The first lens L1, the aperture stop STO, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 form this 5P small distortion imaging lens.

[0048] The aspheric formula is as follows:

[0049]

[0050] Among them, Z represents the relative distance between the point on the aspheric surface h away from the optical axis and the vertex tangent plane on the optical axis tangent to the aspheric surface, c represents the radius of curvature, h represents the distance between the point on the aspheric surface and the optical axis, k represents the cone coefficient, and Ai represents the i-th order aspheric coefficient. The surface curve (structure) can be obtained by substituting the aspheric coefficients of each surface in the lens structure parameter data table into the aspheric formula.

[0051] The lens structure parameter data is as follows Table 1:

[0052]

[0053] Table 1: Lens structure parameter data table of the first embodiment

[0054] The aspheric coefficients of the first embodiment are as shown in Table 2:

[0055]

[0056] Table 2: Aspheric coefficients of the first embodiment

[0057] The characteristic parameter values ​​and distortion results of the first embodiment are shown in Table 3 below:

[0058]

[0059] Table 3: Table of characteristic parameter values ​​of the first embodiment

[0060] Feature parameter description:

[0061] f2 is the focal length of the second lens. f23 is the focal length of the second and third 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. f is the focal length of the lens (focal length is a measure of the convergence or divergence of light in an optical system, and refers to the distance from the optical center of the lens to the focus of light convergence when parallel light is incident). T4 is the core thickness of the fourth lens (the distance from the center point of the L4S1 surface to the center point of the L4S2 surface on the central optical axis). TTL is the total optical length of the lens optical system (the distance from the center point of the L1S1 surface to the center point of the image plane on the central optical axis). DFOV is the field of view angle (in optical instruments, the angle formed by the two edges of the maximum range of the object image of the measured target that can pass through the lens, with the lens of the optical instrument as the vertex, is called the field of view angle). FNO is the value obtained by dividing the focal length by the entrance pupil diameter. FNO limits the amount of light entering the lens. The larger the FNO value, the smaller the amount of light entering and the darker the image; the smaller the FNO value, the larger the amount of light entering and the brighter the image. Optical DIS is the optical distortion value. Optical distortion refers to the ratio of the difference between the ideal image height minus the actual image height in optical theory to the actual image height, which reflects the deviation between the ideal optical position and the actual position of each point on the image. TV DIS is the TV distortion value. TV distortion is the ratio of the maximum difference in imaging height of objects of equal height on the object side to the maximum imaging height on the image side, which reflects the degree of image distortion. Figure 3 As shown, it is the RAY FAN diagram of this embodiment, and the smaller the value is, the better the imaging effect is.

[0062] like Figure 4 The figure shows the distortion and field curvature of light at any pupil in this embodiment. The distortion and field curvature of light at any pupil in any field of view on the wavelength defined by Wave, where the field curvature diagram on the left shows the curve of the distance from the image plane to the paraxial image plane changing with the field of view coordinates, and the T line and S line represent the curves of the change in the meridian and sagittal directions respectively; the distortion diagram on the right shows the difference between the real image height and the ideal image height in each field of view. The closer to the center, the better the imaging effect. It can be seen that the distortion curve of the first embodiment of this application has very small fluctuations, indicating that the distortion is very small.

[0063] like Figure 5 As shown, it is a schematic diagram of the modulation transfer function (MFT) performance of the defocus change at a specified frequency of this embodiment; the more concentrated the concentration of the curve is, the higher the peak value is, and the better the corresponding lens imaging effect is.

[0064] Embodiment 2

[0065] The structure of the second embodiment is similar to that of the first embodiment. Figure 6 As shown, the lens structure data is as follows in Table 4:

[0066]

[0067] Table 4: Lens structure data table of the second embodiment

[0068] The aspheric surface formula is the same as that in the first embodiment, and the aspheric surface coefficients are shown in Table 5 below:

[0069]

[0070] Table 5: Aspheric coefficient table of the second embodiment

[0071] The characteristic parameter values ​​and distortion results of the second embodiment are shown in Table 6 below:

[0072]

[0073] Table 6: Table of characteristic parameter values ​​of the second embodiment

[0074] like Figure 7 As shown, it is the RAY FAN diagram of this embodiment, and the smaller the value is, the better the imaging effect is.

[0075] like Figure 8 The figure shows the distortion and field curvature of light at any pupil in this embodiment. The distortion and field curvature of light at any pupil in any field of view on the wavelength defined by Wave, where the field curvature diagram on the left shows the curve of the distance from the image plane to the paraxial image plane changing with the field of view coordinates, and the T line and S line represent the curves of the change in the meridian and sagittal directions respectively; the distortion diagram on the right shows the difference between the real image height and the ideal image height in each field of view. The closer to the center, the better the imaging effect. It can be seen that the distortion curve of the first embodiment of this application has very small fluctuations, indicating that the distortion is very small.

[0076] like Fig. 9 As shown, it is a schematic diagram of the modulation transfer function (MFT) performance of the defocus change at a specified frequency of this embodiment; the more concentrated the concentration of the curve is, the higher the peak value is, and the better the corresponding lens imaging effect is.

[0077] Embodiment 3

[0078] The structure of the third embodiment is similar to that of the first and second embodiments. Fig.10 As shown, the lens structure data is as follows in Table 7:

[0079]

[0080] Table 7: Lens structure data table of the third embodiment

[0081] The aspheric surface formula is the same as that in the first embodiment, and the aspheric surface coefficients are shown in Table 8 below:

[0082]

[0083] Table 8: Aspheric coefficient table of the third embodiment

[0084] The characteristic parameter values ​​and distortion results of the third embodiment are shown in Table 9 below:

[0085]

[0086] Table 9: Characteristic parameter values ​​of the third embodiment

[0087] like Fig.11 As shown, it is the RAY FAN diagram of this embodiment, and the smaller the value is, the better the imaging effect is.

[0088] like Fig.12 The figure shows the distortion and field curvature of light at any pupil in this embodiment. The distortion and field curvature of light at any pupil in any field of view on the wavelength defined by Wave, where the field curvature diagram on the left shows the curve of the distance from the image plane to the paraxial image plane changing with the field of view coordinates, and the T line and S line represent the curves of the change in the meridian and sagittal directions respectively; the distortion diagram on the right shows the difference between the real image height and the ideal image height in each field of view. The closer to the center, the better the imaging effect. It can be seen that the distortion curve of the first embodiment of this application has very small fluctuations, indicating that the distortion is very small.

[0089] like Fig.13 As shown, it is a schematic diagram of the modulation transfer function (MFT) performance of the defocus change at a specified frequency of this embodiment; the more concentrated the concentration of the curve is, the higher the peak value is, and the better the corresponding lens imaging effect is.

[0090] Example 4

[0091] The structure of the fourth embodiment is similar to the above three embodiments. Fig.14 As shown, the lens structure data is as follows Table 10:

[0092]

[0093] Table 10: Lens structure data table of the fourth embodiment

[0094] The aspheric formula is as follows:

[0095]

[0096] The aspheric coefficients are shown in Table 11:

[0097]

[0098] Table 11: Aspheric coefficient table of the fourth embodiment

[0099] The characteristic parameter values ​​and distortion results of the fourth embodiment are shown in Table 12 below:

[0100]

[0101] Table 12: Table of characteristic parameter values for the fourth embodiment

[0102] As Fig.15 shown, it is the RAY FAN diagram of this embodiment. The smaller the value, the better the imaging effect.

[0103] As Fig.16 shown, it is a schematic diagram of the distortion and field curvature of the light rays at any pupil of this embodiment. For any field of view at the wavelength defined by Wave, the distortion and field curvature of the light rays at any pupil. Among them, the left field curvature diagram shows the curve of the distance from the image plane to the paraxial image plane changing with the field coordinate. The T line and the S line respectively represent the changing curves in the meridional and sagittal directions; the right distortion diagram shows the difference between the actual image height and the ideal image height of each field of view. The closer to the center, the better the imaging effect. It can be seen that the distortion curve of the first embodiment of this application has very small fluctuations, indicating very small distortion.

[0104] As Fig.17 shown, it is a schematic diagram of the modulation transfer function (MFT) performance of defocus change at a specified frequency in this embodiment; the more concentrated the curve, the higher the peak, and the better the imaging effect of the corresponding lens.

[0105] Embodiment 5

[0106] In the above Embodiments 1 to 4, the characteristic parameter values all satisfy the value requirements of 1.293 < f23 / f2 < 1.451; -3.384 < f3 / f < -2.625; 0.686 < f4 / f < 0.836; -1.291 < f5 / f < -0.836; 0.554 < T4 / f < 0.602. For the lens performance of the lens that does not meet the above value requirements, this embodiment is taken as an example:

[0107] The structure of this embodiment is similar to the above embodiments. As Fig.18 shown, its lens structure data is as follows in Table 13:

[0108]

[0109] Table 13: Table of lens structure data for the fifth embodiment

[0110] Its aspheric formula is the same as that of Embodiment 1, and the aspheric coefficients are as follows in Table 14:

[0111]

[0112] Table 14: Table of aspheric coefficients for the fourth embodiment

[0113] The characteristic parameter values and distortion results of the fifth embodiment are as follows in Table 15:

[0114]

[0115] Table 15: Characteristic parameter values ​​of the fifth embodiment

[0116] like Fig.19 As shown, it is the RAY FAN diagram of this embodiment, and the smaller the value is, the better the imaging effect is.

[0117] like Fig. 20 The figure shows the distortion and field curvature of light at any pupil in this embodiment. The distortion and field curvature of light at any pupil in any field of view on the wavelength defined by Wave, where the field curvature diagram on the left shows the curve of the distance from the image plane to the paraxial image plane changing with the field of view coordinates; the distortion diagram on the right shows the difference between the real image height and the ideal image height of each field of view. The closer to the center, the better the imaging effect. It can be seen that the distortion curve of the first embodiment of this application has very small fluctuations, indicating that the distortion is very small. It can be seen that in this embodiment, the distortion is larger than that of embodiments 1-4.

[0118] like Fig.21 As shown, it is a schematic diagram of the modulation transfer function (MFT) performance of the defocus change at a specified frequency of this embodiment; the more concentrated the concentration of the curve is, the higher the peak value is, and the better the corresponding lens imaging effect is.

[0119] The photographic imaging system and smart terminal using the above-mentioned lens involved in the embodiments of the present application are also within the protection scope of the present application.

[0120] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A 5P small distortion imaging lens, characterized in that: It includes a first lens, an aperture stop, a second lens, a third lens, a fourth lens and a fifth lens which are arranged in sequence from the object side to the image side along the optical axis, and there are five lenses with refractive power; The first lens is a negative lens, the second lens is a positive lens, the third lens is a negative lens, the fourth lens is a positive lens, and the fifth lens is a negative lens; Among them, the object side surface of the first lens is concave at the near optical axis, and the image side surface is concave at the near optical axis; the object side surface of the second lens is convex at the near optical axis, and the image side surface is convex at the near optical axis; the object side surface of the third lens is convex at the near optical axis, and the image side surface is concave at the near optical axis; the object side surface of the fourth lens is concave at the near optical axis, and the image side surface is convex at the near optical axis; the object side surface of the fifth lens is convex at the near optical axis, and the image side surface is concave at the near optical axis; the focal length of the second lens is f2, the combined focal length of the second lens and the third lens is f23, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the core thickness of the fourth lens is T4, the focal length of the 5P small distortion imaging lens is f, and the following conditions are met: 1.293<f23 / f2<1.451; -2.803< f3 / f <-2.625; 0.686< f4 / f <0.836; -1.291< f5 / f <-0.836; 0.554<T4 / f<0.

602.

2. A photographic imaging system, comprising the 5P small distortion imaging lens as claimed in claim 1.

3. An intelligent terminal comprising the photographic imaging system as claimed in claim 2.

Images