High-resolution wide-angle imaging lens and electronic equipment

Abstract

The utility model discloses a high-resolution wide-angle imaging lens comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged along an optical axis from an object side to an image side. The first lens has negative diopter, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative diopter, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens has negative diopter, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; the fourth lens has positive diopter, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; according to the utility model, by reasonably distributing the diopters of the first to seventh lenses, the imaging aberration of the lens can be balanced, and large light transmission, high resolution and high contrast of the lens are realized.

Description

Technical Field

[0001] The utility model relates to the technical field of wide-angle imaging lenses, in particular to a high-resolution wide-angle imaging lens and electronic equipment. Background Art

[0002] With the improvement of security awareness in the whole society, security monitoring systems are becoming more and more popular and high-end, chips are being updated, and lens design requirements are also being improved accordingly. Pixels are one of the key factors to measure the quality of a lens. Improving lens pixels while taking into account other performance and costs has become a new challenge for lens designers. Insufficient light transmission will also lead to a decline in image quality. According to optical theory, the larger the field of view of the lens, the greater the distortion. Therefore, the edge pixels of wide-angle lenses account for a small proportion. As the angle increases, aberrations are difficult to correct, which easily produces chromatic aberration and poor color reproduction. Utility Model Content

[0003] In view of this, the purpose of the present invention is to provide a high-resolution wide-angle imaging lens and electronic equipment. The lens can solve at least one technical disadvantage mentioned in the background technology.

[0004] According to one aspect of the utility model, a high-resolution wide-angle imaging lens is provided, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence along an optical axis from the object side to the image side; the first lens has a negative refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has a negative refractive power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens has a negative refractive power, the third lens The object side surface of the third lens is convex, and the image side surface of the third lens is concave; the fourth lens has positive refractive power, the object side surface of the fourth lens is convex, and the image side surface of the fourth lens is convex; the fifth lens has positive refractive power, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is convex; the sixth lens has negative refractive power, the object side surface of the sixth lens is concave, and the image side surface of the sixth lens is convex; the seventh lens has positive refractive power, the object side surface of the seventh lens is convex, and the image side surface of the seventh lens is convex. The utility model can balance the imaging aberration of the lens by reasonably allocating the refractive power of the first lens to the seventh lens, and realize large light transmission, high resolution and high contrast of the lens.

[0005] According to another aspect of the utility model, an electronic device is provided, according to the above-mentioned high-resolution wide-angle imaging lens; and an image sensor, which is configured to receive an image formed by the high-resolution wide-angle imaging lens. In this technical solution, the advantages of the electronic device depend on the high-resolution wide-angle imaging lens, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0007] Figure 1 This is a structural diagram of the optical system of Example 1 of the high-resolution wide-angle imaging lens of the utility model.

[0008] Figure 2 This is an MTF curve diagram of Example 1 of the high-resolution wide-angle imaging lens of the utility model.

[0009] Figure 3 This is a field curvature distortion diagram of Example 1 of the high-resolution wide-angle imaging lens of the utility model.

[0010] Figure 4 This is a structural diagram of the optical system of Example 2 of the high-resolution wide-angle imaging lens of the utility model.

[0011] Figure 5 This is an MTF curve diagram of Example 2 of the high-resolution wide-angle imaging lens of the utility model.

[0012] Figure 6 This is a field curvature distortion diagram of Example 2 of the high-resolution wide-angle imaging lens of the utility model.

[0013] Figure 7 This is a structural diagram of the optical system of Embodiment 3 of the high-resolution wide-angle imaging lens of the utility model.

[0014] Figure 8 This is an MTF curve diagram of Example 3 of the high-resolution wide-angle imaging lens of the utility model.

[0015] Fig. 9 This is a field curvature distortion diagram of Example 3 of the high-resolution wide-angle imaging lens of the utility model;

[0016] Fig.10 It is a structural schematic diagram of the electronic equipment of the utility model.

[0017] The above drawings include the following reference numerals:

[0018] L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, fifth lens; L6, sixth lens; L7, seventh lens; ST, aperture; G, protective glass; IMA, imaging surface. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is particularly noted that the following embodiments are only used to illustrate the present invention, but do not limit the scope of the present invention. Similarly, the following embodiments are only partial embodiments of the present invention rather than all embodiments. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] A high-resolution wide-angle imaging lens, comprising a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7 and a protective glass G arranged in sequence along an optical axis from an object side to an image side;

[0021] The first lens L1 has a negative refractive power, the object side surface of the first lens L1 is a convex surface, and the image side surface of the first lens L1 is a concave surface;

[0022] The second lens L2 has a negative refractive power, the object side surface of the second lens L2 is a convex surface, and the image side surface of the second lens L2 is a concave surface;

[0023] The third lens L3 has a negative refractive power, the object side surface of the third lens L3 is a convex surface, and the image side surface of the third lens L3 is a concave surface;

[0024] The fourth lens L4 has a positive refractive power, the object side surface of the fourth lens L4 is a convex surface, and the image side surface of the fourth lens L4 is a convex surface;

[0025] The fifth lens L5 has a positive refractive power, the object side surface of the fifth lens L5 is a convex surface, and the image side surface of the fifth lens L5 is a convex surface;

[0026] The sixth lens L6 has a negative refractive power, the object side surface of the sixth lens L6 is a concave surface, and the image side surface of the sixth lens L6 is a convex surface;

[0027] The seventh lens L7 has positive refractive power, the object-side surface of the seventh lens L7 is convex, and the image-side surface of the seventh lens L7 is convex.

[0028] The beneficial effects of the above embodiment are as follows: the lens adopts a seven-piece design, with low material cost, and the refractive powers of the first lens L1 to the seventh lens L7 are reasonably distributed, which can balance the imaging aberration of the lens and achieve high light transmission, high resolution and high contrast of the lens.

[0029] Furthermore, the lens satisfies the following relationship:

[0030] 5<|f2 / f|<8; 5<|f3 / f|<8; 5<|f4 / f|<8;

[0031] Among them, f is the total focal length of the lens system; f2 is the focal length of the second lens L2; ​​f3 is the focal length of the third lens L3, and f4 is the focal length of the fourth lens L4.

[0032] The beneficial effects of the above embodiment are as follows: by setting the ratios of the second lens L2 to the fourth lens L4 to the total focal length, if the ratio of the second lens L2 to the total focal length is higher than the upper limit, the lens aperture will become larger. However, if the ratio of the second lens L2 to the total focal length is lower than the lower limit, the lens processing difficulty will increase, affecting the resolution; if the ratio of the third lens L3 to the total focal length is higher than the upper limit, the lens aperture will become larger, the distortion will increase, and the edge pixel ratio will decrease. However, if the ratio of the third lens L3 to the total focal length is lower than the lower limit, the resolution will decrease; if the ratio of the fourth lens L4 to the total focal length is higher than the upper limit, the optical power distribution will be unbalanced and the resolution will decrease. However, if the ratio of the fourth lens L4 to the total focal length is lower than the lower limit, the light will bend and the lens sensitivity will increase. In summary, satisfying the above formula is conducive to improving the resolution and optimizing the f-theta distortion.

[0033] Furthermore, the lens satisfies the following relationship:

[0034] 39<R11<50;

[0035] Wherein, R11 is the radius of curvature of the object side surface of the first lens L1.

[0036] The beneficial effects of the above embodiment are: by controlling the curvature radius of the object side of the first lens L1, it can optimize the f-theta distortion, increase the effect of the waterproof film on the first lens L1, and facilitate the miniaturization design of the lens. By making the lens have positive f-theta distortion, the edge pixel ratio is large, so that the spoiler has a wide angle.

[0037] Furthermore, the lens satisfies the following relationship:

[0038] 1.5<nd1<1.8; 1.8<nd2; 1.5<nd3<1.9;

[0039] Wherein, nd1 is the refractive index of the first lens L1, nd2 is the refractive index of the second lens L2, and nd3 is the refractive index of the third lens L3.

[0040] The beneficial effect of the above embodiment is that a high resolution of the lens is achieved by matching the refractive indices of the first lens L1 to the third lens L3.

[0041] Furthermore, the lens satisfies the following relationship:

[0042] |vd5-vd6|>20;

[0043] Wherein, vd5 is the Abbe coefficient of the fifth lens L5, vd6 is the Abbe coefficient of the sixth lens L6, and the fifth lens L5 and the sixth lens L6 are an achromatic cemented lens group.

[0044] The beneficial effects of the above embodiment are as follows: the fifth lens L5 and the sixth lens L6 adopt a combination of high and low dispersion, which is beneficial to optimizing aberrations and can effectively improve the imaging quality of the lens.

[0045] Furthermore, the lens satisfies the following relationship:

[0046] vd5>60;vd7>60;

[0047] Wherein, vd5 is the Abbe coefficient of the fifth lens L5, and vd7 is the Abbe coefficient of the seventh lens L7.

[0048] The beneficial effects of the above embodiment are as follows: the fifth lens L5 and the seventh lens L7 adopt crown glass with low dispersion coefficient, which is beneficial to optimizing aberrations and can effectively improve the imaging quality of the lens.

[0049] The present invention will be described in more detail below in conjunction with the following tables. It should be noted that the following tables are only specific embodiments of the present invention, and are not restrictive examples.

[0050] For the convenience of description, in the table, surface numbers 1 and 2 are respectively the object-side surface and the image-side surface of the first lens L1; surface numbers 3 and 4 are respectively the object-side surface and the image-side surface of the second lens L2; ​​surface numbers 5 and 6 are respectively the object-side surface and the image-side surface of the third lens L3; surface numbers 7 and 8 are respectively the object-side surface and the image-side surface of the fourth lens L4; surface number 9 is the surface of the stop ST; surface numbers 10 and 11 are respectively the object-side surface and the image-side surface of the fifth lens L5; surface numbers 11 and 12 are respectively the object-side surface and the image-side surface of the sixth lens L6; surface numbers 13 and 14 are respectively the object-side surface and the image-side surface of the seventh lens L7; surface numbers 15 and 16 are respectively the object-side surface and the image-side surface of the protective glass G; and surface number 17 is the surface of the imaging surface IMA.

[0051] For the optical structure of Example 1, please refer to Figure 1 Specific parameters of this embodiment 1 are shown in the following table 1. In this embodiment 1, the focal length of the lens f'=1.3mm, the aperture F=1.60, the field of view FOV=160, and the total length TTL=27.66mm.

[0052] Table 1 Lens parameter table of Example 1

[0053]

[0054] According to Table 1, the conditional formula of Embodiment 1 of the present utility model can be read as follows:

[0055] (1)|f2 / f|=6.692; |f3 / f|=5.923; |f4 / f|=6.077

[0056] (2) R11 = 39.805

[0057] (3)nd1=1.589, nd2=1.911, nd3=1.694

[0058] (4) |vd5-vd6|=49.728

[0059] (5)vd5=68.624; vd7=68.624

[0060] The following is an explanation of the various drawings in Example 1:

[0061] Figure 1 : is the optical system structure diagram of the lens in Example 1. It can be seen from the figure that the aperture ST is located between the fourth lens L4 and the fifth lens L5. The lens of the utility model is composed of seven lenses, has a compact structure, and realizes a miniaturized lens design.

[0062] Figure 2 The MTF curve of Example 1 is shown in FIG. 1 , where the horizontal axis is the frequency, and the unit is line pairs. The vertical axis is the MTF value, and the unit is none. It can be seen from the figure that the contrast at the center of the lens at 125 line pairs is greater than 0.7, and the contrast at the edge of the field of view is greater than 0.5, indicating that the lens has high contrast and high resolution.

[0063] Figure 3 It is the field curvature distortion diagram of Example 1. Among them, the left figure is the field curvature diagram, the horizontal axis is the field curvature value, the unit is millimeter; the vertical axis is the normalized field of view, the unit is infinite rigid. It can be seen from the figure: from the center field of view to the edge field of view, the field curvature changes little, and the imaging quality is good. Among them, the right figure is the optical relative distortion diagram, the horizontal axis is the percentage relative optical distortion value, the unit is %; the vertical axis is the normalized field of view, the unit is infinite rigid. It can be seen from the figure: the f-theta distortion of the lens is a positive value, indicating that the edge pixels of the lens account for a large proportion and the image information is rich.

[0064] For the optical structure of Example 2, please refer to Figure 4 Specific parameters of this embodiment 2 are shown in the following table 2. In this embodiment 2, the focal length of the lens f'=1.3mm, the aperture F=1.65, the field of view FOV=160, and the total length TTL=27.7mm.

[0065] Table 2 Lens parameters of Example 2

[0066]

[0067]

[0068] According to Table 2, the conditional formula of Embodiment 2 of the present utility model can be read as follows:

[0069] (1)|f2 / f|=7.538; |f3 / f|=5.077; |f4 / f|=6.231

[0070] (2) R11 = 46.310

[0071] (3)nd1=1.563, nd2=1.910, nd3=1.693

[0072] (4) |vd5-vd6|=49.728

[0073] (5)vd5=68.624; vd7=68.624

[0074] The following is an explanation of each figure in Example 2:

[0075] Figure 4 : is the optical system structure diagram of the lens in Example 2. It can be seen from the figure that the aperture ST is located between the fourth lens L4 and the fifth lens L5. The lens of the utility model is composed of seven lenses, has a compact structure, and realizes a miniaturized lens design.

[0076] Figure 5 The MTF curve of Example 2 is shown in Figure 2. The horizontal axis is the frequency, and the unit is line pairs. The vertical axis is the MTF value, and the unit is none. It can be seen from the figure that the contrast at the center of the lens at 125 line pairs is greater than 0.7, and the contrast at the edge of the field of view is greater than 0.5, indicating that the lens has high contrast and high resolution.

[0077] Figure 6 It is the field curvature distortion diagram of Example 2. Among them, the left figure is the field curvature diagram, the horizontal axis is the field curvature value, the unit is millimeter; the vertical axis is the normalized field of view, the unit is infinite rigid. It can be seen from the figure: from the center field of view to the edge field of view, the field curvature changes little, and the imaging quality is good. Among them, the right figure is the optical relative distortion diagram, the horizontal axis is the percentage relative optical distortion value, the unit is %; the vertical axis is the normalized field of view, the unit is infinite rigid. It can be seen from the figure: the f-theta distortion of the lens is a positive value, indicating that the edge pixels of the lens account for a large proportion and the image information is rich.

[0078] For the optical structure of Example 3, please refer to Figure 4 Specific parameters of this embodiment 3 are shown in the following table 3. In this embodiment 3, the focal length of the lens f'=1.3mm, the aperture F=1.65, the field of view FOV=160, and the total length TTL=27.7mm.

[0079] Table 3 Lens parameters of Example 3

[0080]

[0081] According to Table 2, the conditional formula of Embodiment 2 of the present utility model can be read as follows:

[0082] (1)|f2 / f|=6.154; |f3 / f|=5.769; |f4 / f|=6.000

[0083] (2) R11 = 40.000

[0084] (3)nd1=1.564, nd2=1.901, nd3=1.694

[0085] (4) |vd5-vd6|=49.728

[0086] (5)vd5=68.624; vd7=68.624

[0087] The following is an explanation of each figure in Example 3:

[0088] Figure 7 : is the optical system structure diagram of the lens in Example 3. It can be seen from the figure that the aperture ST is located between the fourth lens L4 and the fifth lens L5. The lens of the utility model is composed of seven lenses, has a compact structure, and realizes a miniaturized lens design.

[0089] Figure 8 The MTF curve of Example 3 is shown in FIG. 1 , where the horizontal axis is the frequency, and the unit is line pairs. The vertical axis is the MTF value, and the unit is none. It can be seen from the figure that the contrast at the center of the lens at 125 line pairs is greater than 0.7, and the contrast at the edge of the field of view is greater than 0.5, indicating that the lens has high contrast and high resolution.

[0090] Fig. 9 It is the field curvature distortion diagram of Example 3. Among them, the left figure is the field curvature diagram, the horizontal axis is the field curvature value, the unit is millimeter; the vertical axis is the normalized field of view, the unit is infinite rigid. It can be seen from the figure: from the center field of view to the edge field of view, the field curvature changes little, and the imaging quality is good. Among them, the right figure is the optical relative distortion diagram, the horizontal axis is the percentage relative optical distortion value, the unit is %; the vertical axis is the normalized field of view, the unit is infinite rigid. It can be seen from the figure: the f-theta distortion of the lens is a positive value, indicating that the edge pixels of the lens account for a large proportion and the image information is rich.

[0091] On the other hand, now refer to Fig.10 , a schematic structural diagram of an electronic device A according to the utility model will be given. Fig.101 is a schematic diagram of an electronic device (camera) using any of the high-resolution wide-angle imaging lenses according to Embodiments 1 to 3 for an imaging optical system.

[0092] exist Fig.10 , reference numeral A2 denotes an electronic device body, and reference numeral A1 denotes an imaging optical system (interchangeable lens) including any one of the high-resolution wide-angle imaging lenses according to Examples 1 to 3. Reference numeral A3 denotes an image sensor (photoelectric conversion element) such as a CMOS image sensor or a CCD image sensor, which is built into the camera body A2 and receives light (optical image formed by the imaging optical system A1) from the imaging optical system A1 and performs photoelectric conversion.

[0093] By using the high-resolution wide-angle imaging lens according to any one of Embodiments 1 to 3 for electronic equipment such as a digital still camera or the like, electronic equipment having high optical performance can be obtained.

[0094] Various examples may provide electronic devices having high optical performance.

[0095] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A high-resolution wide-angle imaging lens, characterized in that: comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence along the optical axis from the object side to the image side; The first lens has a negative refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; The second lens has a negative refractive power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; The third lens has a negative refractive power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; The fourth lens has positive refractive power, the object side surface of the fourth lens is convex, and the image side surface of the fourth lens is convex; The fifth lens has positive refractive power, the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; The sixth lens has a negative refractive power, the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a convex surface; The seventh lens has positive refractive power, the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a convex surface.

2. A high-resolution wide-angle imaging lens as claimed in claim 1, characterized in that: The lens satisfies the following relationship: 5<|f2 / f|<8; 5<|f3 / f|<8; 5<|f4 / f|<8; Among them, f is the total focal length of the lens system; f2 is the focal length of the second lens; f3 is the focal length of the third lens, and f4 is the focal length of the fourth lens.

3. The high-resolution wide-angle imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: 39＜R11＜50； Wherein, R11 is the radius of curvature of the object side of the first lens.

4. The high-resolution wide-angle imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: 1.5<nd1<1.8; 1.8<nd2; 1.5<nd3<1.9; Wherein, nd1 is the refractive index of the first lens, nd2 is the refractive index of the second lens, and nd3 is the refractive index of the third lens.

5. The high-resolution wide-angle imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: |vd5-vd6|>20; Wherein, vd5 is the Abbe coefficient of the fifth lens, vd6 is the Abbe coefficient of the sixth lens, and the fifth lens and the sixth lens are an achromatic cemented lens group.

6. The high-resolution wide-angle imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: vd5>60;vd7>60; Among them, vd5 is the Abbe coefficient of the fifth lens, and vd7 is the Abbe coefficient of the seventh lens.

7. The high-resolution wide-angle imaging lens according to claim 1, characterized in that: A stop is arranged between the fourth lens and the fifth lens.

8. An electronic device, characterized in that: A high-resolution wide-angle imaging lens according to any one of claims 1 to 7; and An image sensor is configured to receive an image formed by the high-resolution wide-angle imaging lens.

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