Small-size, large-target-surface and high-pixel lens

Abstract

The utility model discloses a small-size, large-target-surface and high-pixel lens. The small-size, large-target-surface and high-pixel lens is sequentially arranged from the object side to the image side along the optical axis of the lens. The aspherical plastic lens has positive focal power; the glass lens has positive focal power; an aspheric plastic lens with negative focal power; the aspherical plastic lens has positive focal power; an aspheric plastic lens with negative focal power; the utility model relates to an aspheric plastic lens with negative focal power. According to the utility model, one piece of glass and six aspheric plastic lenses are adopted, and the focal power of each lens and the shape of each lens surface are reasonably configured, so that the optical system has a larger field angle, meanwhile, the optical system also has the effect of correcting distortion and chromatic aberration, and the advantages of small volume, large target surface and high pixel are better realized.

Description

Technical Field

[0001] The utility model relates to the technical field of optical lenses, in particular to a lens with small volume, large target surface and high pixel count. Background Art

[0002] With the continuous development of mobile information technology, fields such as security monitoring, portable electronic devices, and autonomous driving are also moving towards ultra-thin, full-screen, and ultra-high-definition imaging. This places higher demands on the camera lenses installed in portable electronic devices. Not only must the lenses be small, but they also require greater light flux and a larger imaging area to increase the number of camera pixels, thereby achieving the goal of embedded and integrated products. Although the lenses installed in most mobile phones and other portable electronic devices on the market currently have high pixel counts, they are large in size and occupy too much physical space, which is not conducive to achieving ultra-thinness. Moreover, the lenses do not allow enough light to enter in dark environments, resulting in poor photo quality. Therefore, it is necessary to design an optical lens that combines small size, large image area, and high pixel count to meet the development trend of miniaturized electronic devices. Utility Model Content

[0003] The purpose of this utility model is to address the shortcomings of the existing technology and provide a small-volume, large-target-surface, high-pixel lens. The lens adopts one piece of glass and six aspherical plastic lenses. The total length of the lens is less than 14.5 mm and can be matched with a 1 / 2-inch high-pixel chip to meet the requirements of a small-volume, large-target-surface, high-pixel lens.

[0004] The purpose of the utility model is achieved through the following technical solutions:

[0005] A small-volume, large-area, high-pixel lens, arranged in order from the object side to the image side along the lens optical axis:

[0006] a first lens, wherein the first lens is an aspheric plastic lens with negative optical power, the object-side surface of the first lens is convex, and the image-side surface thereof may be concave;

[0007] a second lens, wherein the second lens is an aspheric plastic lens with positive refractive power, the object-side surface of the second lens is convex or plano-concave, and the image-side surface of the second lens is convex;

[0008] an aperture plate, the aperture plate being arranged between the second lens and the third lens;

[0009] a third lens, the third lens being a glass lens with positive refractive power, the object-side surface of the third lens being convex, and the image-side surface of the third lens being convex;

[0010] a fourth lens, wherein the fourth lens is an aspheric plastic lens having negative optical power, wherein the object-side surface of the fourth lens is concave, and the image-side surface thereof is concave;

[0011] a fifth lens, the fifth lens being an aspheric plastic lens having positive refractive power, the object-side surface of the fifth lens being convex, and the image-side surface of the fifth lens being convex;

[0012] a sixth lens, wherein the sixth lens is an aspheric plastic lens with negative optical power, the object side surface of the sixth lens is a plano-convex surface with recurvature or a concave surface, and the image side surface is a concave surface;

[0013] a seventh lens element, the seventh lens element being an aspheric plastic lens with negative optical power, the object-side surface of the seventh lens element being a concave surface, and the image-side surface of the seventh lens element being a concave surface with a recurvature;

[0014] a filter, the filter being arranged on the image side surface of the seventh lens;

[0015] A protective glass and an image collection element, wherein the protective glass is integrated on the image collection element, and the image collection element is arranged on the image side of the filter.

[0016] Furthermore, the focal length, refractive index and curvature radius of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens respectively meet the following conditions:

[0017]

[0018] Wherein, f1 is the focal length of the first lens, ND1 is the refractive index of the first lens, R11 is the curvature radius of the object side of the first lens, and R12 is the curvature radius of the image side of the first lens; f2 is the focal length of the second lens, ND2 is the refractive index of the second lens, R21 is the curvature radius of the object side of the second lens, and R22 is the curvature radius of the image side of the second lens; f is the focal length of the third lens, ND3 is the refractive index of the third lens, R31 is the curvature radius of the object side of the third lens, and R32 is the curvature radius of the image side of the third lens; f4 is the focal length of the fourth lens, ND4 is the refractive index of the fourth lens, and R41 is the curvature radius of the object side of the fourth lens The radius of curvature is R42, the radius of curvature of the image side surface of the fourth lens; f5 is the focal length of the fifth lens, ND5 is the refractive index of the fifth lens, R51 is the radius of curvature of the object side surface of the fifth lens, and R52 is the radius of curvature of the image side surface of the fifth lens; f6 is the focal length of the sixth lens, ND6 is the refractive index of the sixth lens, R61 is the radius of curvature of the object side surface of the sixth lens, f7 is the focal length of the seventh lens, ND7 is the refractive index of the seventh lens, R71 is the radius of curvature of the object side surface of the seventh lens, and R72 is the radius of curvature of the image side surface of the seventh lens; wherein, the “+” sign indicates that the surface is curved toward the image side, and the “-” sign indicates that the surface is curved toward the object side.

[0019] Furthermore, the lens satisfies the following relationship:

[0020] -1.7≤f1 / f≤-1.5,

[0021] 2.8≤f2 / f≤3.05,

[0022] 1.45≤f3 / f≤1.65,

[0023] -1.4≤f4 / f≤-1.3,

[0024] 1.09≤f5 / f≤1.62,

[0025] -15.8≤f6 / f≤-8.5,

[0026] -10.3≤f7 / f≤-2.52,

[0027] In the relationship, f is the total focal length of the lens, 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 f7 is the focal length of the seventh lens.

[0028] Furthermore, the filter is made of H-K9L glass.

[0029] The beneficial effects of the utility model are:

[0030] This lens utilizes seven lenses with specific optical powers. Through a combination of specialized surface shapes and a rational distribution of optical powers, the lens achieves a more compact structure. Compared to existing lenses on the market, the lens has a focal length of f≤2.8mm and an aperture of F#≤2.6. With an overall length of ≤14.5mm and compatibility with 1 / 2-inch high-pixel chips, it meets the requirements of a compact, large image surface, and high-pixel lens.

[0031] In terms of manufacturability, it uses 1 piece of glass + 6 aspherical plastic lenses, which has low manufacturing cost, uniform and reasonable thickness of each lens and is insensitive, and easy to mold and manufacture. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the optical structure of Example 1 of the present utility model;

[0033] Figure 2 This is a schematic diagram of the optical path structure of Example 1 of the utility model;

[0034] Figure 3 This is a spherical aberration curve diagram for visible light 0.435-0.656 μm in Example 1 of the utility model;

[0035] Figure 4 This is a field curvature curve diagram of visible light 0.435-0.656 μm in Example 1 of the utility model;

[0036] Figure 5 This is a distortion curve diagram of visible light 0.555 μm in Example 1 of the present utility model;

[0037] Figure 6 This is the MTF vs Frequency curve for visible light 0.435-0.656 μm in Example 1 of the present invention;

[0038] Figure 7 This is the Thought Focus MTF curve of Example 1 of the present invention at 100 lp / mm for visible light of 0.435-0.656 μm;

[0039] Figure 8 This is a schematic diagram of the optical structure of Example 2 of the present utility model;

[0040] Figure 9 This is a schematic diagram of the optical path structure of Example 2 of the utility model;

[0041] Figure 10 This is a spherical aberration curve diagram for visible light 0.435-0.656 μm in Example 2 of the present utility model;

[0042] Figure 11 This is a field curvature curve diagram of visible light 0.435-0.656 μm in Example 2 of the present utility model;

[0043] Figure 12 This is a distortion curve diagram of visible light 0.555 μm in Example 2 of the present utility model;

[0044] Figure 13 This is the MTF vs Frequency curve for visible light 0.435-0.656 μm in Example 2 of the present invention;

[0045] Figure 14 This is the Thought Focus MTF curve of Example 2 of the present invention at 100 lp / mm for visible light of 0.435-0.656 μm;

[0046] Reference numerals: 1 - first lens, 2 - second lens, 3 - third lens, 4 - fourth lens, 5 - fifth lens, 6 - sixth lens, 7 - seventh lens, 8 - filter, 9 - image acquisition element, 10 - aperture plate. DETAILED DESCRIPTION

[0047] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. In this specification, the expressions first, second, third, etc. are only used to distinguish one feature from another and do not represent any limitation on the features. The shape of the spherical or aspherical surface is not limited to the spherical or aspherical shape shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0048] In this invention, the paraxial region refers to the region near the optical axis. If a lens surface is convex and the position of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region; if a lens surface is concave and the position of the concave surface is undefined, it means that the lens surface is concave at least in the paraxial region; if a lens surface is not defined as convex, concave, or flat, it means that the lens surface can be convex, concave, or flat. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0049] Unless otherwise defined, all terms (including technical and scientific terms) used in this utility model have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this utility model.

[0050] It should be noted that the embodiments and features in the embodiments of this application may be combined with each other unless they conflict. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. For better understanding and implementation, the utility model is described in detail below with reference to the accompanying drawings.

[0051] The utility model provides a high-pixel wide-angle lens. The surface of the lens adjacent to the object plane is called the object side surface, and the surface of the lens adjacent to the image plane is called the image side surface. Along the lens optical axis, from the object side to the image side, a first lens 1, a second lens 2, a third lens 3, an aperture plate 7, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, a filter 8, a protective glass, an image acquisition element 9, and an aperture plate 10 are arranged in order. The aperture plate 10 is located between the second lens 2 and the third lens 3. The filter 8 is arranged on the image side surface of the seventh lens 7 and is made of H-K9L glass. The image acquisition element 9 is arranged on the image side surface of the filter 8, and the protective glass is integrated with the image acquisition element 9.

[0052] In this utility model, in order to make the optical system present better performance, we need to reasonably select lens materials, reasonably allocate the focal lengths of each lens, and reasonably optimize the optical system during the design process, ultimately optimizing the performance of the optical system. Usually, the presence of aberrations in the optical system will affect the imaging quality of the optical system. Correcting aberrations is the key to optimizing the optical system. There are many ways to correct aberrations. For example, selecting lenses with different refractive indices and large differences in Abbe numbers can eliminate chromatic aberration and spherical aberration to a certain extent. Reasonable allocation and optimization of the focal length and shape of each lens can also correct the aberrations of the system.

[0053] In the present invention, the focal length of the first lens 1 is f1, the focal length of the second lens 2 is f2, the focal length of the third lens 3 is f3, the focal length of the fourth lens 4 is f4, the focal length of the fifth lens 5 is f5, the focal length of the sixth lens 6 is f6, and the focal length of the seventh lens 7 is f7. The total focal length of the entire lens is f, and the ratio of the focal length of each lens to the total focal length of the lens satisfies the following conditions:

[0054] -1.7≤f1 / f≤-1.5,

[0055] 2.8≤f2 / f≤3.05,

[0056] 1.45≤f3 / f≤1.65,

[0057] -1.4≤f4 / f≤-1.3,

[0058] 1.09≤f5 / f≤1.62,

[0059] -15.8≤f6 / f≤-8.5,

[0060] -10.3≤f7 / f≤-2.52.

[0061] In the present invention, taking into account the aberration and temperature drift of the optical system, the focal length, refractive index and curvature radius of each lens respectively meet the following conditions:

[0062]

[0063] Wherein, f1 is the focal length of the first lens 1, ND1 is the refractive index of the first lens 1, R11 is the curvature radius of the object side surface of the first lens 1, and R12 is the curvature radius of the image side surface of the first lens 1; f2 is the focal length of the second lens 2, ND2 is the refractive index of the second lens 2, R21 is the curvature radius of the object side surface of the second lens 2, and R22 is the curvature radius of the image side surface of the second lens 2; f is the focal length of the third lens 3, ND3 is the refractive index of the third lens 3, R31 is the curvature radius of the object side surface of the third lens 3, and R32 is the curvature radius of the image side surface of the third lens 3; f4 is the focal length of the fourth lens 4, ND4 is the refractive index of the fourth lens 4, and R41 is the curvature radius of the object side surface of the fourth lens 4 The surface curvature radius is as follows: R42 is the image side surface curvature radius of the fourth lens 4; f5 is the focal length of the fifth lens 5, ND5 is the refractive index of the fifth lens 5, R51 is the object side surface curvature radius of the fifth lens 5, and R52 is the image side surface curvature radius of the fifth lens 5; f6 is the focal length of the sixth lens 6, ND6 is the refractive index of the sixth lens 6, R61 is the object side surface curvature radius of the sixth lens 6, f7 is the focal length of the seventh lens 7, ND7 is the refractive index of the seventh lens 7, R71 is the object side surface curvature radius of the seventh lens 7, and R72 is the image side surface curvature radius of the seventh lens 7; wherein, the “+” sign indicates that the surface is curved toward the image plane side, and the “-” sign indicates that the surface is curved toward the object plane side.

[0064] In the present invention, f is the total focal length of the lens; TTL is the total optical length of the lens; OBFL is the optical back focus of the lens, which is defined as the distance from the point on the image side of the seventh lens element 7 closest to the image plane to the image plane; IC is the total image height of the 1 / 2-inch chip used in the lens system; and they meet the following conditions: f≤2.8mm, TTL≤14.5mm, IC / TTL≥0.28, TTL / f≤5.4, OBFL / TTL≥0.1.

[0065] In the present invention, the aperture of the lens is F#, which satisfies F#≤2.6; the angle of the lens is FOV, which satisfies FOV≥150°.

[0066] Example 1

[0067] refer to Figure 1 、 Figure 2 As shown, they are respectively a schematic diagram of the optical structure and a schematic diagram of the optical path structure of this embodiment 1.

[0068] In this embodiment, the field of view angle FOV = 150°, and the chief ray angle of the lens is defined as CRA, which satisfies CRA≤36.3°. By rationally selecting lens materials, rationally allocating the focal length and optical power of each lens, and optimizing the optical system, the thickness of each lens is uniform and insensitive, making it easy to mass-produce.

[0069] The lenses in this embodiment are arranged in the following order from the object side to the image side along the lens optical axis:

[0070] The first lens 1 is an aspheric plastic lens with negative optical power, the object side surface of which is convex and the image side surface of which may be concave;

[0071] The second lens 2 is an aspheric plastic lens with positive refractive power, and its object-side surface is convex and its image-side surface is convex;

[0072] Aperture piece 10;

[0073] The third lens 3 is a spherical glass lens (or an aspherical glass lens) with positive refractive power, with a convex object-side surface and a convex image-side surface;

[0074] The fourth lens 4 is an aspheric plastic lens with negative optical power, and its object-side surface and image-side surface are concave;

[0075] The fifth lens 5 is an aspherical plastic lens with positive refractive power, with a convex object-side surface and a convex image-side surface;

[0076] The sixth lens 6 is an aspheric plastic lens with negative optical power, whose object-side surface is a plano-convex surface with an inverse curve and whose image-side surface is a concave surface;

[0077] The seventh lens element 7 is an aspheric plastic lens with negative optical power, whose object-side surface is concave and whose image-side surface is concave with an inverse curve;

[0078] Filter 8, filter 8 is made of H-K9L glass;

[0079] Protective glass and image acquisition element 9 , the protective glass is integrated on the image acquisition element 9 .

[0080] In this embodiment, the first lens element 1 is an aspheric plastic lens with negative optical power, with a convex object-side surface and a concave image-side surface, i.e., a meniscus-shaped lens with negative optical power. This facilitates the design of a wider field of view and rapid light convergence. The third lens element 3 is a low-refractive-index glass lens with a refractive index less than 1.59 and an Abbe number greater than 65. Its primary function is to correct high and low-temperature performance, thereby ensuring stable and excellent resolution at different temperatures.

[0081] Table 1 shows the curvature radius R (unit: mm), the center thickness d (unit: mm), the refractive index (ND), the Abbe constant (VD), and the aspheric K value (Conic) of each lens.

[0082] Table 1

[0083]

[0084] In Table 1, the radius of curvature R represents the degree of curvature of the lens surface. A positive value indicates that the surface is curved toward the image plane, and a negative value indicates that the surface is curved toward the object plane. "INFINITY" indicates that the surface is flat. The center thickness D represents the central axial distance from the current surface to the next surface. The refractive index ND represents the light deflection ability of the current lens material. The Abbe number VD represents the dispersion characteristics of the current lens material for light. The k value represents the numerical value of the best-fit cone coefficient of the aspheric surface. 11 represents the object side surface of the first lens 1, 12 represents the image side surface of the first lens 1, and so on.

[0085] In this embodiment, the aspheric surfaces of the first lens 1, the second lens 2, the fourth lens 4, the fifth lens 5, the sixth lens 6, and the seventh lens 7 can all be defined by the following equation for an even-order aspheric surface:

[0086] ,

[0087] Where Z is the sagittal height of the lens along the optical axis, k is the conic coefficient of the surface, γ is the lens height, c is the lens curvature, A, B, C, D, E, F, and G are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspheric polynomial.

[0088] Table 2 lists various coefficients of aspherical surfaces of each optical surface of the first lens 1 , the second lens 2 , the fourth lens 4 , the fifth lens 5 , the sixth lens 6 , and the seventh lens 7 .

[0089] Table 2

[0090]

[0091] refer to Figure 3 As shown, this is the spherical aberration curve of the lens in the embodiment of the visible light 0.435-0.656μm. Figure 3 The longitudinal spherical aberration values ​​of 5 different wavelength spectra are shown in Figure 1. Among them, LONGITUDINAL SPHERICAL ABER represents different fields of view, FOCUS (MILLIMETERS) represents the longitudinal spherical aberration value, from Figure 3 As can be seen from the figure, within different fields of view, the chromatic aberration of each wavelength relative to the central wavelength is controlled within ±0.015mm, which shows that the vertical axis chromatic aberration of the lens is well corrected.

[0092] refer to Figure 4 As shown in FIG, it is the field curvature curve of the visible light 0.435-0.656 μm of the lens of this embodiment, wherein the vertical axis ASTIGMATIC FIELD CURVES represents different fields of view, and the horizontal axis FOCUS (MILLIMETERS) represents the field area (mm). Figure 4 It can be seen that the field curvature offset in the tangential and sagittal directions on the image plane is controlled within ±0.03mm, indicating that the field curvature of the lens is well corrected.

[0093] refer to Figure 5 Figure 2 shows the distortion curve for the lens of this embodiment at 0.555μm visible light. The horizontal axis represents F-tan (Theta) distortion (unit: %), and the vertical axis represents the half-image height (unit: mm). As can be seen from the figure, the distortion within the full field of view of the lens is within -65%, indicating that the distortion is well corrected.

[0094] refer to Figure 6 The figure shows the MTF vs. Frequency curve of the lens in the visible light range of 0.435-0.656μm in this embodiment. The horizontal axis represents the frequency (unit: lp / mm) and the vertical axis represents the MTF value. Figure 6 It can be seen that at a spatial frequency of 250lp / mm, the MTF value of the lens within a 151° field of view is above 0.15, indicating that the lens has a very high resolution.

[0095] refer to Figure 7 The following is the Thought Focus MTF curve of the lens in this embodiment at a frequency of 100 lp / mm under visible light of 0.435-0.656 μm. The horizontal axis represents the defocus amount (unit: mm) and the vertical axis represents the MTF value. Figure 7 It can be seen that the lens has a small defocus in each field of view of visible light 0.435-0.656μm, which ensures clear pictures when shooting at night.

[0096] Depend on Figure 3 、 4 , 5 It can be seen that the field curvature, distortion and chromatic aberration of the lens in this embodiment can be well corrected.

[0097] In this embodiment 1, the total focal length of the lens system is f=2.8mm, the aperture value F#=2.6, the total length TTL of the lens is 14.4mm, the optical back focus distance OBFL of the lens is 1.05mm, and the field of view angle DFOV of the lens matching a 1 / 2-inch chip is 150°.

[0098] Example 2

[0099] refer to Figure 8 、 Figure 9 As shown, they are respectively a schematic diagram of the optical structure and a schematic diagram of the optical path structure of this embodiment 2.

[0100] In this embodiment, the field of view angle FOV = 150°, and the chief ray angle of the lens is defined as CRA, which satisfies CRA≤34.9°. By rationally selecting lens materials, rationally allocating the focal length and optical power of each lens, and optimizing the optical system, the thickness of each lens is uniform and insensitive, which is easy to mass-produce. Figure 2 shown.

[0101] The lenses in this embodiment are arranged in the following order from the object side to the image side along the lens optical axis:

[0102] The first lens 1 is an aspheric plastic lens with negative optical power, the object side surface of which is convex, and the image side surface of which may be concave;

[0103] The second lens 2 is an aspheric plastic lens with positive refractive power, the object side surface of which is a plano-concave surface, and the image side surface of which is a convex surface;

[0104] Aperture piece 10;

[0105] The third lens 3 is a spherical glass lens (or an aspherical glass lens) with positive refractive power, with its object-side surface being convex and its image-side surface being convex;

[0106] The fourth lens 4 is an aspheric plastic lens with negative optical power, whose object-side surface is concave and whose image-side surface is concave;

[0107] The fifth lens 5 is an aspheric plastic lens with positive refractive power, whose object-side surface is convex and whose image-side surface is convex;

[0108] The sixth lens 6 is an aspheric plastic lens with negative optical power, whose object-side surface is a concave surface with a reverse curve and whose image-side surface is a concave surface;

[0109] The seventh lens element 7 is an aspheric plastic lens with negative optical power, whose object-side surface is concave and whose image-side surface is concave with an inverse curve;

[0110] Filter 8, filter 8 is made of H-K9L glass;

[0111] Protective glass and image acquisition element 9, the protective glass is integrated on the image acquisition element.

[0112] In this embodiment, the second lens element 2 is an aspheric plastic lens with positive optical power. Its object-side surface is a plano-concave surface, and its image-side surface is a convex surface, i.e., a meniscus-shaped lens with negative optical power. This lens element helps reduce the optical power of the first lens element 1, thereby reducing sensitivity and improving resolution. The seventh lens element 7 is a low-refractive-index plastic lens with a refractive index of less than 1.55 and an Abbe number greater than 55. Its main function is to improve resolution and image brightness uniformity.

[0113] Table 3 shows the curvature radius R (unit: mm), the center thickness d (unit: mm), the refractive index (ND), the Abbe constant (VD), and the aspheric K value (Conic) of each lens.

[0114] Table 3

[0115]

[0116] In Table 4, the radius of curvature R represents the degree of curvature of the lens surface. A positive value indicates that the surface is curved toward the image plane, and a negative value indicates that the surface is curved toward the object plane. "INFINITY" indicates that the surface is flat. The center thickness D represents the central axial distance from the current surface to the next surface. The refractive index ND represents the light deflection ability of the current lens material. The Abbe number VD represents the dispersion characteristics of the current lens material for light. The k value represents the numerical value of the best-fit conic coefficient of the aspheric surface. 11 represents the object side surface of the first lens 1, 12 represents the image side surface of the first lens 1, and so on.

[0117] In this embodiment 2, the aspheric surfaces of the first lens 1, the second lens 2, the fourth lens 4, the fifth lens 5, the sixth lens 6, and the seventh lens 7 can all be defined by the following equation for an even-order aspheric surface:

[0118] ,

[0119] Where Z is the sagittal height of the lens along the optical axis, k is the conic coefficient of the surface, γ is the lens height, c is the lens curvature, A, B, C, D, E, F, and G are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspheric polynomial.

[0120] Table 4 shows various coefficients of the aspherical surfaces of the first lens 1 , the second lens 2 , the fourth lens 4 , the fifth lens 5 , the sixth lens 6 , and the seventh lens 7 .

[0121] Table 4

[0122]

[0123] refer to Figure 10 The figure shows the spherical aberration curve of the lens in the embodiment of the present invention for visible light of 0.435-0.656μm, which shows the longitudinal spherical aberration values ​​of 5 different wavelength spectra. Among them, LONGITUDINAL SPHERICAL ABER represents different fields of view, and FOCUS (MILLIMETERS) represents the longitudinal spherical aberration value. Figure 10 It can be seen that within different fields of view, the chromatic aberration of each wavelength relative to the central wavelength is controlled within ±0.025mm, which shows that the vertical axis chromatic aberration of this lens is well corrected.

[0124] refer to Figure 11 As shown in FIG, the field curvature curve of the visible light of the lens of this embodiment is 0.435-0.656 μm. Among them, the vertical axis ASTIGMATIC FIELD CURVES represents different fields of view, and the horizontal axis FOCUS (MILLIMETERS) represents the field area (mm). Figure 11 It can be seen that the field curvature offset in the meridional and sagittal directions on the image plane is controlled within ±0.025mm, indicating that the field curvature of the lens is well corrected.

[0125] refer to Figure 12 As shown in the figure, the distortion curve of the lens of this embodiment at visible light of 0.555μm is shown, the horizontal axis represents F-tan (Theta) distortion (unit: %), the vertical axis represents the half-image height value (unit: mm), Figure 12 It can be seen that the distortion of the lens is within -65% within the full field of view of the lens, indicating that the distortion is well corrected.

[0126] refer to Figure 13 The figure shows the MTF vs Frequency curve of the lens in the visible light range of 0.435-0.656μm in this embodiment. The horizontal axis represents the spatial frequency (unit: lp / mm) and the vertical axis represents the MTF value. Figure 13 It can be seen that the MTF within the entire field of view is corrected, indicating that the lens has a very high resolution.

[0127] refer to Figure 14 The following is the Thought Focus MTF curve of the lens in this embodiment at a frequency of 100 lp / mm under visible light of 0.435-0.656 μm. The horizontal axis represents the defocus amount (unit: mm) and the vertical axis represents the MTF value. Figure 14 It can be seen that the lens has a small defocus of 0.435-0.656μm visible light, which ensures clear pictures when shooting at night.

[0128] Depend on Figure 10 、 11 As can be seen from Figures 12, the field curvature, distortion and chromatic aberration of the lens in this embodiment can be well corrected.

[0129] In this embodiment 2, the total focal length of the lens system is f=2.6mm, the aperture value F#=2.4, the total length TTL of the lens is 14.4mm, the optical back focus distance OBFL of the lens is 1.1mm, and the field of view angle DFOV of the lens matching a 1 / 2-inch chip is 143°.

[0130] From the F-Tan(θ) distortion curves, field curvature curves, and vertical axis chromatic aberration curves of the above embodiments, it can be seen that the optical lens provided by the utility model is small in size, has the advantages of high imaging quality, a large target area, a high pixel count, and good resolution.

[0131] Based on the disclosure of the above description, those skilled in the art may also make appropriate changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and any modifications and variations of the present invention should also fall within the scope of protection of the claims of the present invention. In addition, although certain specific terms are used in this description, these terms are for convenience only and do not constitute any limitation to the present invention.

Claims

1. A small-volume, large-area, high-pixel lens, characterized by: Set along the lens optical axis from the object side to the image side in order: a first lens, wherein the first lens is an aspheric plastic lens with negative optical power, the object-side surface of the first lens is convex, and the image-side surface thereof may be concave; a second lens, wherein the second lens is an aspheric plastic lens with positive refractive power, the object-side surface of the second lens is convex or plano-concave, and the image-side surface of the second lens is convex; a third lens, the third lens being a glass lens with positive refractive power, the object-side surface of the third lens being convex, and the image-side surface of the third lens being convex; a fourth lens, wherein the fourth lens is an aspheric plastic lens having negative optical power, wherein the object-side surface of the fourth lens is concave, and the image-side surface thereof is concave; a fifth lens, the fifth lens being an aspheric plastic lens having positive refractive power, the object-side surface of the fifth lens being convex, and the image-side surface of the fifth lens being convex; a sixth lens, wherein the sixth lens is an aspheric plastic lens with negative optical power, the object side surface of the sixth lens is a plano-convex surface with recurvature or a concave surface, and the image side surface is a concave surface; The seventh lens is an aspheric plastic lens with negative optical power, the object side surface of the seventh lens is a concave surface, and the image side surface is a concave surface with a reverse curve.

2. The small-volume, large-area, high-pixel lens according to claim 1, characterized in that: The focal length ranges of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are respectively -4.7 to -3.95, +7.7 to +8.7, +3.9 to +4.7, -3.95 to -3.7, +3.1 to +4.3, -41.9 to -24.1 and -27.3 to -7.1; The refractive index value ranges corresponding to the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are respectively: 1.50～1.55、1.60～1.68、1.45～1.63、1.60～1.68、1.50～1.55、1.50～1.55、1.50～1.55； The object side surface curvature radii of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens respectively range from +8.0 to +10.1, +17.9 to +78.9, +23.9 to +71.9, +77.9 to +93.4, +4.5 to +4.6, -52.7 to -33.2 and -78.2 to -22.8; The image-side surface curvature radii corresponding to the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are in the range of +1.6 to +1.83, -7.4 to -5.19, -2.9 to -2.5, +2.2 to +2.5, -4.0 to -2.2, +21.2 to +40.0, and +4.0 to +41.2, respectively; wherein the "+" sign indicates that the lens surface is curved toward the image plane, and the "-" sign indicates that the lens surface is curved toward the object plane.

3. The small-volume, large-area, high-pixel lens according to claim 1, characterized in that: The lens also satisfies the following relationship: -1.7≤f1 / f≤-1.5, In the relationship, f is the total focal length of the lens, and f1 is the focal length of the first lens.

4. The small-volume, large-area, high-pixel lens according to claim 1, characterized in that: The lens also satisfies the following relationship: 2.8≤f2 / f≤3.05, In the relationship, f is the total focal length of the lens, and f2 is the focal length of the second lens.

5. The small-volume, large-area, high-pixel lens according to claim 1, characterized in that: The lens also satisfies the following relationship: 1.45≤f3 / f≤1.65, In the relationship, f is the total focal length of the lens, and f3 is the focal length of the third lens.

6. The small-volume, large-area, high-pixel lens according to claim 1, characterized in that: The lens also satisfies the following relationship: -1.4≤f4 / f≤-1.3, In the relationship, f is the total focal length of the lens, and f4 is the focal length of the fourth lens.

7. The small-volume, large-area, high-pixel lens according to claim 1, characterized in that: The lens also satisfies the following relationship: 1.09≤f5 / f≤1.62, In the relationship, f is the total focal length of the lens, and f5 is the focal length of the fifth lens.

8. The small-volume, large-area, high-pixel lens according to claim 1, characterized in that: The lens also satisfies the following relationship: -15.8≤f6 / f≤-8.5, In the relationship, f is the total focal length of the lens, and f6 is the focal length of the sixth lens.

9. The small-volume, large-area, high-pixel lens according to claim 1, characterized in that: The lens also satisfies the following relationship: -10.3≤f7 / f≤-2.52, In the relationship, f is the total focal length of the lens, and f7 is the focal length of the seventh lens.

10. The small-volume, large-area, high-pixel lens according to any one of claims 1 to 9, characterized in that: Along the lens optical axis from the object side to the image side, it is also set: an aperture plate, the aperture plate being arranged between the second lens and the third lens; a filter, the filter being disposed on the image-side surface of the seventh lens; A protective glass and an image collection element, wherein the protective glass is integrated on the image collection element, and the image collection element is arranged on the image side of the filter.

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