Optical imaging lens

Abstract

The utility model relates to the technical field of optical lenses, in particular to an optical imaging lens, which sequentially comprises an aperture diaphragm, a first lens, a second lens and a third lens from an object side to an image side along an optical axis. The first lens has positive focal power, the object side surface of the first lens is a convex surface, and the image side surface is a convex surface; the second lens has negative focal power, the object side surface of the second lens is a convex surface, and the image side surface is a concave surface; the third lens has positive or negative focal power, and the image side surface of the third lens is a convex surface; the fourth lens has negative focal power, the object side surface of the fourth lens is a convex surface, and the image side surface is a concave surface; the fifth lens has positive focal power, the object side surface of the fifth lens is a convex surface, and the image side surface is a convex surface; the sixth lens has negative focal power, and the image side surface of the sixth lens is a concave surface; the first to sixth lenses are plastic aspheric lenses; the conditional expression is TTL / flt; 1; tTL is the total optical length of the lens, and f is the effective focal length of the lens. Through reasonable matching of the parameters of the lenses, long focus, large aperture, small distortion and lightening and thinning are realized, and the lens has the advantage of high imaging quality.

Description

Technical Field

[0001] The utility model relates to the technical field of optical lenses, in particular to an optical imaging lens. Background Art

[0002] With the rapid development of science and technology, mobile communication devices such as mobile phones have developed into important communication tools in daily life. As an important information collection component in mobile phones, mobile phone lenses are one of the key components of mobile phones, realizing functions such as taking pictures, shooting videos and scanning. The telephoto system is an optical system that can clearly shoot distant objects. It is often used in mobile phone lenses to expand the shooting function of mobile phones. Due to the small number of lenses with telephoto optical systems in the early days, there were problems such as large size, long optical length, and low clarity, which made it impossible to adapt to the high pixel requirements of current chips and the development trend of thin and light mobile phones. Therefore, it is urgent to develop an optical imaging lens with large aperture, telephoto, and high imaging quality. Utility Model Content

[0003] In view of the above-mentioned shortcomings and deficiencies of the prior art, the utility model provides a large aperture and high-resolution optical imaging lens, which is mainly composed of six lenses, and the six lenses all adopt a plastic aspherical design. By reasonably matching the optical focal length and surface shape of each lens and distributing parameters, it is ensured that the lens achieves telephoto, large aperture, small distortion and lightness, and has the advantages of high imaging quality.

[0004] In order to achieve the above-mentioned purpose, the main technical solutions adopted by the utility model include:

[0005] An optical imaging lens, which is composed of the following components from the object side to the image side along the optical axis:

[0006] Aperture diaphragm;

[0007] The first lens has positive power, and the object side surface of the first lens is convex near the optical axis, and the image side surface is convex near the optical axis;

[0008] The second lens has negative power, the object side surface of the second lens is convex near the optical axis, and the image side surface is concave near the optical axis;

[0009] The third lens has positive or negative power, and the image side surface of the third lens is convex near the optical axis;

[0010] The fourth lens has negative power, the object side surface of the fourth lens is convex near the optical axis, and the image side surface is concave near the optical axis;

[0011] A fifth lens element having positive refractive power, wherein the object side surface of the fifth lens element is convex near the optical axis, and the image side surface is convex near the optical axis;

[0012] The sixth lens has negative optical power, and the image side surface of the sixth lens is concave near the optical axis;

[0013] The first to sixth lenses are all plastic aspherical lenses;

[0014] The lens satisfies the following conditional formula:

[0015] TTL / f<1;

[0016] Where TTL is the total optical length of the lens and f is the effective focal length of the lens.

[0017] By properly matching the focal length and surface shape of each lens and allocating parameters, the lens is guaranteed to achieve long focus, large aperture, small distortion, and thinness, with the advantages of high imaging quality. By controlling the ratio of the total length of the optical imaging lens to the effective focal length, the optical imaging lens is made to be low-sensitivity and miniaturized, while allowing light to better converge on the image plane.

[0018] Furthermore, the lens satisfies the following conditional formula:

[0019] 3.8 <FNO / tan(HFOV)<5

[0020] Among them, FNO is the aperture number of the lens, and HFOV is half of the maximum field of view of the lens.

[0021] By controlling the ratio of the lens's aperture number to the tangent value of half the lens's maximum field of view, the lens is guaranteed to have sufficient light throughput and imaging range.

[0022] Furthermore, the lens satisfies the following conditional formula:

[0023] 0.56 <BL / ΣAT<0.66

[0024] Wherein, BL is the distance from the most convex point of the image side surface of the sixth lens to the imaging plane on the optical axis, and ΣAT is the sum of the spacing distances between every two adjacent lenses in the lens on the optical axis.

[0025] By controlling the ratio of the distance from the most convex point on the image side of the sixth lens to the imaging plane on the optical axis to the sum of the spacing distances between every two adjacent lenses on the optical axis, sufficient space is provided on the image side end, further ensuring that the lens has better long-focus telephoto performance.

[0026] Furthermore, the lens satisfies the following conditional formula:

[0027] 0.4 <f1 / f<0.5

[0028] Wherein, f1 is the focal length of the first lens.

[0029] By controlling the ratio of the focal length of the first lens to the focal length of the lens, the spherical aberration and field curvature of the lens can be effectively balanced.

[0030] Furthermore, the lens satisfies the following conditional formula:

[0031] 0.4 <CT6 / CT5<0.8

[0032] Wherein, CT6 is the center thickness of the sixth lens on the optical axis, and CT5 is the center thickness of the fifth lens on the optical axis.

[0033] By controlling the ratio of the center thickness of the sixth lens on the optical axis to the center thickness of the fifth lens on the optical axis, it can be ensured that the total length of the optical system is not too large.

[0034] Furthermore, the lens satisfies the following conditional formula:

[0035] 1.5 <FNO / Imgh<2.5

[0036] Among them, FNO is the aperture number of the lens, and Imgh is half of the real image height corresponding to the maximum field of view of the lens.

[0037] By controlling the ratio of the lens's aperture number to the true image height of the maximum field of view, the lens can have sufficient light transmittance to ensure high-definition images.

[0038] The beneficial effects of the utility model are:

[0039] The utility model provides a large aperture and high-resolution optical imaging lens, which is mainly composed of six lenses, and the six lenses are all designed with plastic aspherical surfaces. By reasonably matching the focal length and surface shape of each lens and allocating parameters, it is ensured that the lens achieves long focus, large aperture, small distortion and lightness, and has the advantages of high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0041] Figure 2 This is a distortion curve diagram of Example 1 of the utility model;

[0042] Figure 3 This is a field curvature curve diagram of Example 1 of the utility model;

[0043] Figure 4 is a spherical aberration curve diagram of Example 1 of the utility model;

[0044] Figure 5 This is a schematic diagram of the structure of Embodiment 2 of the present utility model;

[0045] Figure 6This is a distortion curve diagram of Example 2 of the utility model;

[0046] Figure 7 This is a field curvature curve diagram of Example 2 of the present utility model;

[0047] Figure 8 is a spherical aberration curve diagram of Example 2 of the utility model;

[0048] Fig. 9 This is a schematic diagram of the structure of Embodiment 3 of the present utility model;

[0049] Fig.10 This is a distortion curve diagram of Example 3 of the utility model;

[0050] Fig.11 This is a field curvature curve diagram of Example 3 of the present utility model;

[0051] Fig.12 is a spherical aberration curve diagram of Example 3 of the utility model;

[0052] Fig.13 This is a schematic diagram of the structure of Embodiment 4 of the present utility model;

[0053] Fig.14 This is a distortion curve diagram of Example 4 of the utility model;

[0054] Fig.15 It is a field curvature curve diagram of Example 4 of the utility model;

[0055] Fig.16 is a spherical aberration curve diagram of Example 4 of the utility model;

[0056] Fig.17 This is a schematic diagram of the structure of Embodiment 5 of the present utility model;

[0057] Fig.18 This is a distortion curve diagram of Example 5 of the present utility model;

[0058] Fig.19 This is a field curvature curve diagram of Example 5 of the present utility model;

[0059] Fig. 20 This is a spherical aberration curve diagram of Example 5 of the utility model.

[0060] In the figure: 1, first lens; 2, second lens; 3, third lens; 4, fourth lens; 5, fifth lens; 6, sixth lens; 7, aperture stop; 8, filter. DETAILED DESCRIPTION

[0061] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0062] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0063] In this document, the surface of each lens closest to the object is called the object-side surface, and the surface of each lens closest to the imaging plane is called the image-side surface.

[0064] An optical imaging lens provided in an embodiment of the utility model is composed of the following components in sequence from the object side to the image side along the optical axis:

[0065] Aperture diaphragm;

[0066] The first lens 1 has positive power, the object side surface of the first lens 1 is convex near the optical axis, and the image side surface is convex near the optical axis;

[0067] The second lens 2 has negative optical power, the object side surface of the second lens 2 is convex near the optical axis, and the image side surface is concave near the optical axis;

[0068] The third lens 3 has positive or negative power, and the image side surface of the third lens 3 near the optical axis is convex;

[0069] The fourth lens 4 has a negative optical power, the object side surface of the fourth lens 4 is convex near the optical axis, and the image side surface is concave near the optical axis;

[0070] A fifth lens element 5 has positive refractive power, and the object side surface of the fifth lens element 5 is convex near the optical axis, and the image side surface is convex near the optical axis;

[0071] The sixth lens element 6 has a negative optical power, and the image side surface of the sixth lens element 6 is concave near the optical axis;

[0072] The first lens 1 to the sixth lens 6 are all plastic aspherical lenses;

[0073] The lens satisfies the following conditional formula:

[0074] TTL / f<1;

[0075] Where TTL is the total optical length of the lens and f is the effective focal length of the lens.

[0076] By properly matching the focal length and surface shape of each lens and allocating parameters, the lens is guaranteed to achieve long focus, large aperture, small distortion, and thinness, with the advantages of high imaging quality. By controlling the ratio of the total length of the optical imaging lens to the effective focal length, the optical imaging lens is made to be low-sensitivity and miniaturized, while allowing light to better converge on the image plane.

[0077] Specifically, the lens satisfies the following conditional formula:

[0078] 3.8 <FNO / tan(HFOV)<5

[0079] Among them, FNO is the aperture number of the lens, and HFOV is half of the maximum field of view of the lens.

[0080] By controlling the ratio of the lens's aperture number to the tangent value of half the lens's maximum field of view, the lens is guaranteed to have sufficient light throughput and imaging range.

[0081] Specifically, the lens satisfies the following conditional formula:

[0082] 0.56 <BL / ΣAT<0.66

[0083] Wherein, BL is the distance from the most convex point of the image-side surface of the sixth lens 6 to the imaging plane on the optical axis, and ΣAT is the sum of the spacing distances between every two adjacent lenses in the lens on the optical axis.

[0084] By controlling the ratio of the distance from the most convex point on the image side of the sixth lens 6 to the imaging plane on the optical axis to the sum of the spacing distances between every two adjacent lenses on the optical axis, sufficient space is provided on the image side end, further ensuring that the lens has better long-focus telephoto performance.

[0085] Specifically, the lens satisfies the following conditional formula:

[0086] 0.4 <f1 / f<0.5

[0087] Wherein, f1 is the focal length of the first lens 1.

[0088] By controlling the ratio of the focal length of the first lens 1 to the focal length of the lens, the spherical aberration and the field curvature of the lens can be effectively balanced.

[0089] Specifically, the lens satisfies the following conditional formula:

[0090] 0.4 <CT6 / CT5<0.8

[0091] Wherein, CT6 is the center thickness of the sixth lens 6 on the optical axis, and CT5 is the center thickness of the fifth lens 5 on the optical axis.

[0092] By controlling the ratio of the center thickness of the sixth lens 6 on the optical axis to the center thickness of the fifth lens 5 on the optical axis, it can be ensured that the total length of the optical system is not too large.

[0093] Specifically, the lens satisfies the following conditional formula:

[0094] 1.5 <FNO / Imgh<2.5

[0095] Among them, FNO is the aperture number of the lens, and Imgh is half of the real image height corresponding to the maximum field of view of the lens.

[0096] By controlling the ratio of the lens's aperture number to the true image height of the maximum field of view, the lens can have sufficient light transmittance to ensure high-definition images.

[0097] The above-mentioned lens may further include a filter 8 for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface according to the specific needs of the embodiment. In the absence of specific requirements, the filter 8 or the protective glass may not be used.

[0098] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0099] Example 1

[0100] The present embodiment provides an optical imaging lens, which is composed of an aperture 7, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6 and a filter 8 in sequence from the object side to the image side along the optical axis. Incident light passes through the above components in sequence and is finally imaged on the image plane. The first lens 1 has positive focal power, and its object side surface is convex at the near optical axis, and the image side surface is convex at the near optical axis. The second lens 2 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The third lens 3 has positive focal power, and its 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 4 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The fifth lens 5 has positive focal power, and its object side surface is convex at the near optical axis, and the image side surface is convex at the near optical axis. The sixth lens 6 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The filter 8 is arranged between the sixth lens 6 and the image plane.

[0101] Table 1 shows the surface type, radius of curvature, thickness and material properties of each lens in Example 1. The units of the radius of curvature and thickness are both millimeters (mm).

[0102] Table 1 is a table of lens parameters of Example 1.

[0103]

[0104]

[0105] In this embodiment, the surface shape x of each aspheric lens can be defined by, but not limited to, the following aspheric formula:

[0106]

[0107] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the cone coefficient; A i The following Table 2 shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 of the aspheric mirror surfaces S1-S12 that can be used in Example 1.

[0108] Table 2 is a table of high-order coefficients of various aspherical mirror surfaces in Example 1.

[0109]

[0110]

[0111] Table 3 below shows important parameters in Example 1.

[0112] Table 3 is a table of important parameters of Example 1.

[0113]

[0114] The specific lens structure of this embodiment is as follows Figure 1 Table 1-3 and Figure 1-4 The lens shape and various properties of the lens of the current embodiment are shown, indicating that the lens achieves long focus, large aperture, small distortion and light weight, and has the advantages of high imaging quality.

[0115] Example 2

[0116] The present embodiment provides an optical imaging lens, which is composed of an aperture 7, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6 and a filter 8 in sequence from the object side to the image side along the optical axis. Incident light passes through the above components in sequence and is finally imaged on the image plane. The first lens 1 has positive focal power, and its object side surface is convex at the near optical axis, and the image side surface is convex at the near optical axis. The second lens 2 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The third lens 3 has positive focal power, and its 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 4 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The fifth lens 5 has positive focal power, and its object side surface is convex at the near optical axis, and the image side surface is convex at the near optical axis. The sixth lens 6 has negative focal power, and its object side surface is concave at the near optical axis, and the image side surface is concave at the near optical axis. The filter 8 is arranged between the sixth lens 6 and the image plane.

[0117] Table 4 shows the surface type, radius of curvature, thickness and material properties of each lens in Example 2. The units of the radius of curvature and thickness are both millimeters (mm).

[0118] Table 4 is a table of lens parameters of Example 2.

[0119]

[0120] In this embodiment, each aspheric surface shape can be defined by the formula (1) in the above embodiment 1. Table 5 below shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20 of each aspheric mirror surface S1-S12 that can be used in embodiment 2.

[0121] Table 5 is a table of high-order coefficients of each aspherical mirror surface in Example 2.

[0122]

[0123]

[0124] Table 6 below shows important parameters in Example 2.

[0125] Table 6 is a table of important parameters of Example 2.

[0126]

[0127] The specific lens structure of this embodiment is as follows Figure 5 Table 4-6 and Figure 5-8 The lens shape and various properties of the lens of the current embodiment are shown, indicating that the lens achieves long focus, large aperture, small distortion and light weight, and has the advantages of high imaging quality.

[0128] Example 3

[0129] The present embodiment provides an optical imaging lens, which is composed of an aperture 7, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6 and a filter 8 in sequence from the object side to the image side along the optical axis. Incident light passes through the above components in sequence and is finally imaged on the image plane. The first lens 1 has positive focal power, and its object side surface is convex at the near optical axis, and the image side surface is convex at the near optical axis. The second lens 2 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The third lens 3 has negative focal power, and its object side surface is concave at the near optical axis, and the image side surface is convex at the near optical axis. The fourth lens 4 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The fifth lens 5 has positive focal power, and its object side surface is convex at the near optical axis, and the image side surface is convex at the near optical axis. The sixth lens 6 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The filter 8 is arranged between the sixth lens 6 and the image plane.

[0130] Table 7 shows the surface type, radius of curvature, thickness and material properties of each lens in Example 3. The units of the radius of curvature and thickness are both millimeters (mm).

[0131] Table 7 is a table of lens parameters of Example 3.

[0132]

[0133] In this embodiment, each aspheric surface shape can be defined by the formula (1) in the above embodiment 1. Table 8 below shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20 of each aspheric mirror surface S1-S12 that can be used in embodiment 3.

[0134] Table 8 is a table of high-order coefficients of each aspherical mirror surface in Example 3.

[0135]

[0136]

[0137] Table 9 below shows important parameters in Example 3.

[0138] Table 9 is a table of important parameters of Example 3.

[0139]

[0140] The specific lens structure of this embodiment is as follows Figure 7 Table 7-9 and Figure 9-12The lens shape and various properties of the lens of the current embodiment are shown, indicating that the lens achieves long focus, large aperture, small distortion and light weight, and has the advantages of high imaging quality.

[0141] Example 4

[0142] The present embodiment provides an optical imaging lens, which is composed of an aperture 7, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6 and a filter 8 in sequence from the object side to the image side along the optical axis. Incident light passes through the above components in sequence and is finally imaged on the image plane. The first lens 1 has positive focal power, and its object side surface is convex at the near optical axis, and the image side surface is convex at the near optical axis. The second lens 2 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The third lens 3 has negative focal power, and its object side surface is concave at the near optical axis, and the image side surface is convex at the near optical axis. The fourth lens 4 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The fifth lens 5 has positive focal power, and its object side surface is convex at the near optical axis, and the image side surface is convex at the near optical axis. The sixth lens 6 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The filter 8 is arranged between the sixth lens 6 and the image plane.

[0143] Table 10 shows the surface type, radius of curvature, thickness and material properties of each lens in Example 4. The units of the radius of curvature and thickness are both millimeters (mm).

[0144] Table 10 is a table of lens parameters of Example 4.

[0145]

[0146] In this embodiment, each aspheric surface shape can be defined by the formula (1) in the above embodiment 1. Table 11 below shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20 of each aspheric mirror surface S1-S12 that can be used in embodiment 4.

[0147] Table 11 is a table of high-order coefficients of each aspherical mirror surface in Example 4.

[0148]

[0149] Table 12 below shows important parameters in Example 4.

[0150] Table 12 is a table of important parameters of Example 4.

[0151]

[0152] The specific lens structure of this embodiment is as follows Fig.13 Table 10-12 and Figure 13-16 The lens shape and various properties of the lens of the current embodiment are shown, indicating that the lens achieves long focus, large aperture, small distortion and light weight, and has the advantages of high imaging quality.

[0153] Example 5

[0154] The present embodiment provides an optical imaging lens, which is composed of an aperture 7, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6 and a filter 8 in sequence from the object side to the image side along the optical axis. Incident light passes through the above components in sequence and is finally imaged on the image plane. The first lens 1 has positive focal power, and its object side surface is convex at the near optical axis, and the image side surface is convex at the near optical axis. The second lens 2 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The third lens 3 has negative focal power, and its object side surface is concave at the near optical axis, and the image side surface is convex at the near optical axis. The fourth lens 4 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The fifth lens 5 has positive focal power, and its object side surface is convex at the near optical axis, and the image side surface is convex at the near optical axis. The sixth lens 6 has negative focal power, and its object side surface is convex at the near optical axis, and the image side surface is concave at the near optical axis. The filter 8 is arranged between the sixth lens 6 and the image plane.

[0155] Table 13 shows the surface type, radius of curvature, thickness and material properties of each lens in Example 5. The units of the radius of curvature and thickness are both millimeters (mm).

[0156] Table 13 is a table of lens parameters of Example 5.

[0157]

[0158]

[0159] In this embodiment, each aspheric surface shape can be defined by the formula (1) in the above embodiment 1. Table 14 below shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20 of each aspheric mirror surface S1-S12 that can be used in embodiment 5.

[0160] Table 14 is a table of high-order coefficients of each aspherical mirror surface in Example 5.

[0161]

[0162] Table 15 below shows important parameters in Example 5.

[0163] Table 15 is a table of important parameters of Example 5.

[0164]

[0165]

[0166] The specific lens structure of this embodiment is as follows Fig.17 Table 13-15 and Figure 17-20 The lens shape and various properties of the lens of the current embodiment are shown, indicating that the lens achieves long focus, large aperture, small distortion and light weight, and has the advantages of high imaging quality.

[0167] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An optical imaging lens, characterized in that: Along the optical axis from the object side to the image side, it is composed of: Aperture diaphragm; The first lens has positive power, and the object side surface of the first lens is convex near the optical axis, and the image side surface is convex near the optical axis; The second lens has negative power, the object side surface of the second lens is convex near the optical axis, and the image side surface is concave near the optical axis; The third lens has positive or negative power, and the image side surface of the third lens is convex near the optical axis; The fourth lens has negative power, the object side surface of the fourth lens is convex near the optical axis, and the image side surface is concave near the optical axis; A fifth lens element having positive refractive power, wherein the object side surface of the fifth lens element is convex near the optical axis, and the image side surface is convex near the optical axis; The sixth lens has negative optical power, and the image side surface of the sixth lens is concave near the optical axis; The first to sixth lenses are all plastic aspherical lenses; The lens satisfies the following conditional formula: TTL / f<1; Where TTL is the total optical length of the lens and f is the effective focal length of the lens.

2. The optical imaging lens according to claim 1, wherein: The lens satisfies the following conditional formula: 3.8 <FNO / tan(HFOV)<5 Among them, FNO is the aperture number of the lens, and HFOV is half of the maximum field of view of the lens.

3. The optical imaging lens according to claim 1, wherein: The lens satisfies the following conditional formula: 0.56 <BL / ΣAT<0.66 Wherein, BL is the distance from the most convex point of the image side surface of the sixth lens to the imaging plane on the optical axis, and ΣAT is the sum of the spacing distances between every two adjacent lenses in the lens on the optical axis.

4. The optical imaging lens according to claim 1, wherein: The lens satisfies the following conditional formula: 0.4 <f1 / f<0.5 Wherein, f1 is the focal length of the first lens.

5. The optical imaging lens according to claim 1, wherein: The lens satisfies the following conditional formula: 0.4 <CT6 / CT5<0.8 Wherein, CT6 is the center thickness of the sixth lens on the optical axis, and CT5 is the center thickness of the fifth lens on the optical axis.

6. The optical imaging lens according to claim 1, wherein: The lens satisfies the following conditional formula: 1.5 <FNO / Imgh<2.5 Among them, FNO is the aperture number of the lens, and Imgh is half of the real image height corresponding to the maximum field of view of the lens.

Images