Imaging lens system

Abstract

An imaging lens system includes: a first lens having a positive refractive power and including a concave object side surface; a second lens having negative refractive power; a third lens having positive refractive power; a fourth lens having negative refractive power; a fifth lens having negative refractive power; a sixth lens having positive refractive power; and a seventh lens having a negative refractive power, in which the first to seventh lenses are disposed in order from the object side toward the imaging surface, at least one of the first to seventh lenses has an aspheric surface, the number of lenses having refractive power is 7, the imaging lens system has a focal length in a range of 3.0 mm to 3.5 mm, and a field of view of the imaging lens system is 100 degrees or more, TTL / ImgHlt; 1.5, TTL is the distance from the object side surface of the first lens to the imaging surface, ImgH is the height of the imaging surface, and D12 / D23lt; 0.14, D12 is the distance from the image-side surface of the first lens to the object-side surface of the second lens, and D23 is the distance from the image-side surface of the second lens to the object-side surface of the third lens.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2020-0046525 filed on April 17, 2020, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety for all purposes by reference. Technical Field

[0003] The present application relates to an imaging lens system comprising seven lenses. Background Art

[0004] Small-sized cameras can be installed in wireless terminal devices. For example, small-sized cameras can be installed on the front surface and the rear surface of the wireless terminal device, respectively. Since small-sized cameras are used for various purposes such as outdoor landscape pictures, indoor portrait pictures, etc., they are required to have a performance level comparable to that of ordinary cameras. However, because the installation space of small-sized cameras is limited by the size of the wireless terminal device, it may be difficult for small-sized cameras to achieve high performance. In particular, since severe distortion occurs in cameras with a field of view of 100 degrees or more, it is necessary to develop a camera or imaging lens system with low distortion and a field of view of 100 degrees or more. Summary of the invention

[0005] This Summary is provided to introduce some concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0006] An imaging lens system that significantly reduces distortion while having a wide field of view.

[0007] In one general aspect, an imaging lens system includes 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 from the object side. In the imaging lens system, the first lens has a positive refractive power, and the object side surface of the first lens is a concave surface. The field of view of the imaging lens system is 100 degrees or greater. In the imaging lens system, the distance TTL from the object side surface of the first lens to the imaging surface and the height ImgH of the imaging surface satisfy TTL / ImgH<1.5.

[0008] The second lens may have negative refractive power.

[0009] The third lens may have positive refractive power.

[0010] The object-side surface of the fourth lens element may be a convex surface.

[0011] The object-side surface of the fifth lens may be a concave surface.

[0012] The sixth lens may have positive refractive power.

[0013] The seventh lens may have negative refractive power.

[0014] The imaging lens system may satisfy -2.0<(ImgH / (f*tan(FOV / 2))-1)*100<2.0, where f is the focal length of the imaging lens system, and FOV is the field of view of the imaging lens system.

[0015] The imaging lens system can satisfy D12 / D23<0.14, wherein D12 is the distance from the image side surface of the first lens to the object side surface of the second lens, and D23 is the distance from the image side surface of the second lens to the object side surface of the third lens.

[0016] The imaging lens system may satisfy 1.2<D23 / D34, wherein D23 is the distance from the image side surface of the second lens to the object side surface of the third lens, and D34 is the distance from the image side surface of the third lens to the object side surface of the fourth lens.

[0017] The imaging lens system may satisfy -0.2<f3 / f2<-0.04, where f2 is the focal length of the second lens, and f3 is the focal length of the third lens.

[0018] In another general aspect, an imaging lens system includes a plurality of lenses disposed on the object side of an imaging plane. In the imaging lens system, -2.0<(ImgH / (f*tan(FOV / 2))-1)*100<2.0, and TTL / ImgH<1.5, wherein ImgH is the height of the imaging plane, f is the focal length of the imaging lens system, FOV is the field of view of the imaging lens system, and TTL is the distance from the object side of the lens disposed closest to the object side among the plurality of lenses to the imaging plane.

[0019] The field of view of the imaging lens system can be 100 degrees or greater.

[0020] Among the plurality of lenses, a lens closest to the object side may have positive refractive power, and an object-side surface of the lens closest to the object side may be a concave surface.

[0021] The imaging lens system can satisfy 1.6<TTL / f<1.8.

[0022] The imaging lens system may satisfy 0.2<Tmax / ImgH<0.3, wherein Tmax is the center thickness of a lens having the largest center thickness on the optical axis among the plurality of lenses.

[0023] The multiple lenses may include a first lens with positive refractive power, a second lens with negative refractive power, a third lens with positive refractive power, a fourth lens with negative refractive power, a fifth lens with negative refractive power, a sixth lens with positive refractive power and a seventh lens with negative refractive power, which are arranged in sequence from the object side.

[0024] Other features and aspects will be apparent from the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A configuration of an imaging lens system according to a first example is shown.

[0026] Figure 2 yes Figure 1 Aberration curves of the imaging lens system shown in .

[0027] Figure 3 A configuration of an imaging lens system according to a second example is shown.

[0028] Figure 4 yes Figure 3 Aberration curves of the imaging lens system shown in .

[0029] Figure 5 A configuration of an imaging lens system according to a third example is shown.

[0030] Figure 6 yes Figure 5 Aberration curves of the imaging lens system shown in .

[0031] Figure 7 A configuration of an imaging lens system according to a fourth example is shown.

[0032] Figure 8 yes Figure 7 Aberration curves of the imaging lens system shown in .

[0033] Fig. 9 A configuration of an imaging lens system according to a fifth example is shown.

[0034] Fig.10 yes Fig. 9 Aberration curves of the imaging lens system shown in .

[0035] Like reference numerals denote like elements throughout the drawings and detailed description. The drawings may not be drawn to scale, and the relative sizes, proportions, and depictions of elements in the drawings may be exaggerated for clarity, illustration, and convenience. DETAILED DESCRIPTION

[0036] The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and / or systems described herein will be apparent to one of ordinary skill in the art. The order of operations described herein is merely an example and is not limited to those set forth herein, but may be changed as will be apparent to one of ordinary skill in the art, except for operations that must occur in a particular order. In addition, descriptions of functions and configurations that would be well known to one of ordinary skill in the art may be omitted for increased clarity and brevity.

[0037] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to one of ordinary skill in the art.

[0038] Here, it should be noted that with respect to examples or embodiments, for example, with respect to what an example or embodiment may include or implement, the use of the term "may" means that there is at least one example or embodiment that includes or implements such features, and all examples and embodiments are not limited to this.

[0039] Throughout the specification, when an element such as a layer, a region, or a substrate is described as being “on”, “connected to”, or “coupled to” another element, it may be directly “on”, “connected to”, or “coupled to” another element, or one or more other elements may be present in between. However, when an element is described as being “directly on”, “directly connected to”, or “directly coupled to” another element, there may be no other elements in between.

[0040] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more.

[0041] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Instead, these terms are merely used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of this example, what is referred to as a first member, a first component, a first region, a first layer, or a first portion in the examples described herein may be referred to as a second member, a second component, a second region, a second layer, or a second portion.

[0042] For ease of description, spatially relative terms, such as "above," "upper," "below," and "lower," may be used herein to facilitate description of the relationship of one element to another element as shown in the figures. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figure is turned over, an element described as being "above" or "upper" relative to another element would then be "below" or "lower" relative to the other element. Thus, depending on the spatial orientation of the device, the term "above" includes both "above" and "below" orientations. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein will be interpreted accordingly.

[0043] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the articles "a", "an" and "the" are intended to include plural forms. The terms "comprises", "includes" and "having" illustrate the presence of the features, quantities, operations, components, elements and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements and / or combinations thereof.

[0044] Due to manufacturing techniques and / or tolerances, the shapes shown in the drawings may vary. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include changes in shapes that occur during manufacturing.

[0045] The features of the examples described herein can be combined in various ways, which will be apparent after understanding the disclosure of this application. In addition, although the examples described herein have various configurations, it will be apparent after understanding the disclosure of this application that other configurations are possible.

[0046] The drawings may not be drawn to scale, and the relative sizes, proportions, and depictions of elements in the drawings may be exaggerated for clarity, illustration, and convenience.

[0047] In the example, the first lens refers to the lens closest to the object (or subject), and the seventh lens refers to the lens closest to the imaging plane (or image sensor). In the example, the units of the radius of curvature, thickness, TTL (the distance from the object side of the first lens to the imaging plane), 2Img_HT (the diagonal length of the imaging plane), and focal length are expressed in millimeters (mm).

[0048] The thickness of the lens, the gap between lenses, and TTL refer to the distance of the lens along the optical axis. In addition, in the description of the lens shape, the configuration of one surface being convex means that the paraxial region of the corresponding surface is convex, and the configuration of one surface being concave means that the paraxial region of the surface is concave. Therefore, even when one surface of the lens is described as convex, the edge of the lens can be concave. Similarly, even when one surface of the lens is described as concave, the edge of the lens can be convex.

[0049] The imaging lens system includes five or more lenses. For example, the imaging lens system may include a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged in sequence from the object side. However, the number of lenses constituting the imaging lens system is not limited to five. As an example, the imaging lens system may also include a sixth lens arranged on the image side of the fifth lens. As another example, the imaging lens system may also include a seventh lens arranged on the image side of the sixth lens. The first lens to the fifth lens or the first lens to the seventh lens are arranged with a certain gap. For example, in the paraxial region, each lens does not contact the image side surface and the object side surface of the adjacent lens. In addition, the F number of the imaging lens system may be 2.08 or less.

[0050] The first lens has a refractive power. For example, the first lens has a positive refractive power. One surface of the first lens is a concave surface. For example, the object side surface of the first lens is a concave surface. The first lens includes an aspheric surface. For example, both surfaces of the first lens may be aspheric. The first lens may have an inflection point. For example, the inflection point may be formed on at least one surface of the object side surface and the image side surface of the first lens. The first lens may be formed of a material having a high transmittance and improved processability. For example, the first lens may be formed of plastic. The first lens has a certain Abbe number. For example, the Abbe number of the first lens may be 25 or greater.

[0051] The second lens has a refractive power. For example, the second lens may have a negative refractive power. The second lens has a convex surface. For example, the object side surface of the second lens may be a convex surface. The second lens has an aspheric surface. For example, both surfaces of the second lens may be aspheric surfaces. The second lens may be formed of a material having a high light transmittance and improved processability. For example, the second lens may be formed of plastic. The second lens has a higher refractive index than the first lens. For example, the refractive index of the second lens may be 1.6 or greater.

[0052] The third lens has a refractive power. For example, the third lens has a positive refractive power. At least one surface of the third lens is a convex surface. For example, the object side surface of the third lens may be a convex surface. The third lens has an aspheric surface. For example, both surfaces of the third lens may be aspheric surfaces. The third lens may be formed of a material having a high light transmittance and improved processability. For example, the third lens may be formed of plastic. The third lens has a smaller refractive index than the second lens. For example, the refractive index of the third lens may be less than 1.6.

[0053] The fourth lens has a refractive power. For example, the fourth lens has a negative refractive power. The object side surface or the image side surface of the fourth lens is concave. The fourth lens has an aspheric surface. For example, both surfaces of the fourth lens may be aspheric. The fourth lens may have an inflection point. For example, the inflection point may be formed on at least one of the object side surface and the image side surface of the fourth lens. The fourth lens may be formed of a material having a high light transmittance and improved processability. For example, the fourth lens may be formed of plastic. The fourth lens has a certain refractive index. For example, the refractive index of the fourth lens may be 1.65 or greater.

[0054] The fifth lens has a refractive power. For example, the fifth lens may have a negative refractive power. One surface of the fifth lens is a concave surface. For example, the object side surface of the fifth lens may be a concave surface. The fifth lens may have a shape with an inflection point. For example, the inflection point may be formed on at least one of the object side surface and the image side surface of the fifth lens. The fifth lens has an aspherical surface. For example, both surfaces of the fifth lens may be aspherical surfaces. The fifth lens may be formed of a material having a high light transmittance and improved processability. For example, the fifth lens may be formed of plastic. The fifth lens always has a higher refractive index than the third lens.

[0055] The sixth lens has a refractive power. For example, the sixth lens has a positive refractive power. One surface of the sixth lens is a convex surface. For example, the object side surface of the sixth lens may be a convex surface. The sixth lens may have a shape with an inflection point. For example, the inflection point may be formed on at least one of the object side surface and the image side surface of the sixth lens. The sixth lens has an aspherical surface. For example, both surfaces of the sixth lens may be aspherical surfaces. The sixth lens may be formed of a material having a high transmittance and improved processability. For example, the sixth lens may be formed of plastic. The sixth lens has a refractive index smaller than that of the fifth lens. For example, the refractive index of the sixth lens may be less than 1.6.

[0056] The seventh lens has a refractive power. For example, the seventh lens has a negative refractive power. At least one surface of the seventh lens may be a concave surface. For example, the image side surface of the seventh lens may be a concave surface. The seventh lens may have a shape with an inflection point. For example, one or more inflection points may be formed on at least one surface of the object side surface and the image side surface of the seventh lens. The seventh lens has an aspherical surface. For example, both surfaces of the seventh lens may be aspherical surfaces. The seventh lens may be formed of a material having a high light transmittance and improved processability. For example, the seventh lens may be formed of plastic. The seventh lens has a refractive index substantially similar to that of the sixth lens. For example, the refractive index of the seventh lens may be less than 1.6.

[0057] As described above, each of the first to seventh lenses has an aspherical surface. The aspherical surfaces of the first to seventh lenses may be represented by Equation 1 as follows.

[0058] Equation 1:

[0059]

[0060] In Equation 1, "c" is the inverse of the radius of curvature of each lens, "k" is the cone constant, "r" is the distance from a specific point on the aspheric surface of the lens to the optical axis, "A to J" is the aspheric constant, and "Z" (or SAG) is the height from a specific point on the aspheric surface of the lens to the vertex of the aspheric surface in the direction of the optical axis.

[0061] The imaging lens system also includes filters, image sensors and apertures.

[0062] The filter is disposed on the object side of the image sensor. The filter may block certain wavelengths of light. For example, the filter may block infrared wavelengths of light. The image sensor forms an imaging surface on which light refracted by the lens may be formed. The image sensor is configured to convert an optical signal into an electrical signal. The image sensor may be in the form of a CMOS type image sensor. An aperture is disposed to control the amount of light incident on the lens. For example, the aperture may be disposed between the second lens and the third lens.

[0063] The imaging lens system may satisfy one or more of the following conditional expressions.

[0064] Conditional expressions (CE 1 to CE 9)

[0065] CE 1: 100 <FOV

[0066] CE 2: -2.0<(ImgH / (f*tan(FOV / 2))-1)*100<2.0

[0067] CE 3: TTL / ImgH<1.5

[0068] CE 4: D12 / D23<0.14

[0069] CE 5: 1.2 <D23 / D34

[0070] CE 6: -0.2 <f3 / f2<-0.04

[0071] CE 7: 1.6 <TTL / f<1.8

[0072] CE 8: 3.0 <Tmin<Tmax<5.0

[0073] CE 9: 0.2 <Tmax / ImgH<0.3

[0074] In the above conditional expressions, "FOV" is the field of view of the imaging lens system, "ImgH" is the height of the imaging plane, "f" is the focal length of the imaging lens system, "D12" is the distance from the image side surface of the first lens to the object side surface of the second lens, "D23" is the distance from the image side surface of the second lens to the object side surface of the third lens, "D34" is the distance from the image side surface of the third lens to the object side surface of the fourth lens, "f2" is the focal length of the second lens, "f3" is the focal length of the third lens, "Tmax" is the center thickness on the optical axis of the lens having the maximum center thickness on the optical axis among the lenses constituting the imaging lens system, and "Tmin" is the center thickness on the optical axis of the lens having the minimum center thickness on the optical axis among the lenses constituting the imaging lens system.

[0075] Hereinafter, imaging lens systems according to various examples will be described.

[0076] Reference Figure 1 An imaging lens system according to a first example is described.

[0077] The imaging lens system 100 may include a first lens 110 , a second lens 120 , a third lens 130 , a fourth lens 140 , a fifth lens 150 , a sixth lens 160 , and a seventh lens 170 .

[0078] The first lens 110 has positive refractive power. In the first lens 110, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the first lens 110. The second lens 120 has negative refractive power. In the second lens 120, the object side surface is convex and the image side surface is concave. The third lens 130 has positive refractive power. In the third lens 130, the object side surface is convex and the image side surface is convex. The fourth lens 140 has negative refractive power. In the fourth lens 140, the object side surface is convex and the image side surface is concave. Inflection points are formed on the object side surface and the image side surface of the fourth lens 140. The fifth lens 150 has negative refractive power. In the fifth lens 150, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the fifth lens 150. The sixth lens 160 has positive refractive power. In the sixth lens 160, the object side surface is convex and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the sixth lens 160. The seventh lens 170 has negative refractive power. In the seventh lens 170, the object side surface is a concave surface and the image side surface is a concave surface. Inflection points are formed on the object side surface and the image side surface of the seventh lens 170.

[0079] The imaging lens system 100 may further include an optical filter 180 and an image sensor 190. The optical filter 180 is disposed between the seventh lens 170 and the image sensor 190. A stop ST is disposed between the second lens 120 and the third lens 130. The imaging lens system 100 has a field of view of 100.03 degrees.

[0080] The imaging lens system 100 configured as described above exhibits Figure 2 The aberration characteristics shown in Figure 2 As shown in , the imaging lens system 100 can significantly reduce spherical aberration, curvature aberration, and distortion aberration while having a field of view of 100 degrees or more. Tables 1 and 2 show the lens characteristics and asphericity values ​​of the imaging lens system 100.

[0081] Table 1

[0082]

[0083]

[0084] Table 2

[0085] Surface number r k A B C D S1 -4.7643 4.1511 0.1421 -0.1558 0.4105 -1.0505 S2 -2.9729 -39.1283 0.1239 0.0264 -1.1159 4.8498 S3 1.8671 -10.8346 0.0767 -0.0665 -0.8452 2.9541 S4 1.5820 -6.2937 -0.2398 1.8699 -18.6841 145.9078 S6 8.7200 71.1361 -0.0194 -0.0277 -0.3624 4.3215 S7 -3.0068 4.2188 -0.1397 -0.7011 8.7645 -57.3486 S8 3.5191 -58.5347 -0.2005 0.3851 -6.3390 37.7137 S9 2.9616 -3.1119 -0.0505 -0.5718 2.5043 -8.5813 S10 -1.3969 -13.1791 -0.3486 2.0299 -9.5016 34.4080 S11 -2.6717 -3.3228 -0.0808 0.1067 0.2569 -2.5591 S12 5.2959 -98.6532 -0.1984 0.4411 -1.2646 2.9349 S13 -1.0992 -1.7406 0.1564 -0.4891 1.3376 -2.9984 S14 -18.2257 0.0000 -0.0422 -0.1879 0.4401 -0.5350 S15 1.1886 -3.8777 -0.1754 0.1609 -0.1107 0.0559 Surface number E F G H J S1 1.9492 -2.5362 2.3463 -1.5624 0.7511 S2 -12.1584 20.4288 -24.1899 20.5986 -12.6633 S3 -3.7175 -3.6817 22.6586 -42.9487 48.0268 S4 -815.2217 3235.5687 -9211.291 18950.991 -28169.75 S6 -27.3864 122.0517 -414.3108 1053.0258 -1930.636 S7 252.0694 -779.2777 1729.4105 -2781.659 3242.7152 S8 -135.1075 329.6431 -573.3994 724.5027 -666.7108 S9 23.0903 -44.8330 61.6010 -60.0796 41.5948 S10 -90.6749 173.2562 -240.2417 241.6892 -175.6878 S11 9.1090 -19.6524 28.7023 -29.3198 21.0568 S12 -4.7612 5.1321 -3.4043 0.9995 0.3796 S13 4.9675 -5.8607 4.8969 -2.8961 1.2080 S14 0.4198 -0.2266 0.0868 -0.0239 0.0048 S15 -0.0212 0.0062 -0.0014 0.0003 0.0000

[0086] In the following, reference will be made to Figure 3 An imaging lens system according to a second example is described.

[0087] The imaging lens system 200 may include a first lens 210 , a second lens 220 , a third lens 230 , a fourth lens 240 , a fifth lens 250 , a sixth lens 260 , and a seventh lens 270 .

[0088] The first lens 210 has positive refractive power. In the first lens 210, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the first lens 210. The second lens 220 has negative refractive power. In the second lens 220, the object side surface is convex and the image side surface is concave. The third lens 230 has positive refractive power. In the third lens 230, the object side surface is convex and the image side surface is convex. The fourth lens 240 has negative refractive power. In the fourth lens 240, the object side surface is convex and the image side surface is concave. Inflection points are formed on the object side surface and the image side surface of the fourth lens 240. The fifth lens 250 has negative refractive power. In the fifth lens 250, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the fifth lens 250. The sixth lens 260 has positive refractive power. In the sixth lens 260, the object side surface is convex and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the sixth lens 260. The seventh lens 270 has negative refractive power. In the seventh lens 270, the object side surface is a concave surface and the image side surface is a concave surface. Inflection points are formed on the object side surface and the image side surface of the seventh lens 270.

[0089] The imaging lens system 200 may further include an optical filter 280 and an image sensor 290. The optical filter 280 is disposed between the seventh lens 270 and the image sensor 290. A stop ST is disposed between the second lens 220 and the third lens 230. The imaging lens system 200 has a field of view of 100.05 degrees.

[0090] The imaging lens system 200 configured as above has the following features: Figure 4 The aberration characteristics shown in Figure 4 As shown in , the imaging lens system 200 can significantly reduce spherical aberration, curvature aberration, and distortion aberration while having a field of view of 100 degrees or more. Tables 3 and 4 show the lens characteristics and aspheric values ​​of the imaging lens system 200.

[0091] Table 3

[0092]

[0093] Table 4

[0094]

[0095]

[0096] In the following, reference will be made to Figure 5An imaging lens system according to a third example is described.

[0097] The imaging lens system 300 may include a first lens 310 , a second lens 320 , a third lens 330 , a fourth lens 340 , a fifth lens 350 , a sixth lens 360 , and a seventh lens 370 .

[0098] The first lens 310 has positive refractive power. In the first lens 310, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the first lens 310. The second lens 320 has negative refractive power. In the second lens 320, the object side surface is convex and the image side surface is concave. The third lens 330 has positive refractive power. In the third lens 330, the object side surface is convex and the image side surface is convex. The fourth lens 340 has negative refractive power. In the fourth lens 340, the object side surface is convex and the image side surface is concave. Inflection points are formed on the object side surface and the image side surface of the fourth lens 340. The fifth lens 350 has negative refractive power. In the fifth lens 350, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the fifth lens 350. The sixth lens 360 has positive refractive power. In the sixth lens 360, the object side surface is convex and the image side surface is convex. Inflection points are formed on the object side and image side of the sixth lens 360. The seventh lens 370 has negative refractive power. In the seventh lens 370, the object side is convex and the image side is concave. Inflection points are formed on the object side and image side of the seventh lens 370.

[0099] The imaging lens system 300 may further include an optical filter 380 and an image sensor 390. The optical filter 380 is disposed between the seventh lens 370 and the image sensor 390. A stop ST is disposed between the second lens 320 and the third lens 330. The imaging lens system 300 has a field of view of 100.02 degrees.

[0100] The imaging lens system 300 configured as described above has Figure 6 The aberration characteristics shown in Figure 6 As shown in , the imaging lens system 300 can significantly reduce spherical aberration, curvature aberration, and distortion aberration while having a field of view of 100 degrees or more. Tables 5 and 6 show the lens characteristics and asphericity values ​​of the imaging lens system 300.

[0101] Table 5

[0102]

[0103] Table 6

[0104]

[0105]

[0106] In the following, reference will be made to Figure 7 An imaging lens system according to a fourth example is described.

[0107] The imaging lens system 400 may include a first lens 410 , a second lens 420 , a third lens 430 , a fourth lens 440 , a fifth lens 450 , a sixth lens 460 , and a seventh lens 470 .

[0108] The first lens 410 has positive refractive power. In the first lens 410, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the first lens 410. The second lens 420 has negative refractive power. In the second lens 420, the object side surface is convex and the image side surface is concave. The third lens 430 has positive refractive power. In the third lens 430, the object side surface is convex and the image side surface is convex. The fourth lens 440 has negative refractive power. In the fourth lens 440, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the fourth lens 440. The fifth lens 450 has negative refractive power. In the fifth lens 450, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the fifth lens 450. The sixth lens 460 has positive refractive power. In the sixth lens 460, the object side surface is convex and the image side surface is concave. Inflection points are formed on the object side surface and the image side surface of the sixth lens 460. The seventh lens 470 has a negative refractive power. In the seventh lens 470, the object side surface is a convex surface and the image side surface is a concave surface. Inflection points are formed on the object side surface and the image side surface of the seventh lens 470.

[0109] The imaging lens system 400 may further include an optical filter 480 and an image sensor 490. The optical filter 480 is disposed between the seventh lens 470 and the image sensor 490. A stop (not shown) may be disposed between the third lens 430 and the fourth lens 440. The imaging lens system 400 has a field of view of 100.40 degrees.

[0110] The imaging lens system 400 configured as described above exhibits Figure 8 The aberration characteristics shown in Figure 8 As shown in , the imaging lens system 400 can significantly reduce spherical aberration, curvature aberration, and distortion aberration while having a field of view of 100 degrees or more. Tables 7 and 8 show the lens characteristics and aspheric values ​​of the imaging lens system 400.

[0111] Table 7

[0112]

[0113] Table 8

[0114]

[0115]

[0116] In the following, reference will be made to Fig. 9 An imaging lens system according to a fifth example is described.

[0117] The imaging lens system 500 may include a first lens 510 , a second lens 520 , a third lens 530 , a fourth lens 540 , a fifth lens 550 , a sixth lens 560 , and a seventh lens 570 .

[0118] The first lens 510 has positive refractive power. In the first lens 510, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the first lens 510. The second lens 520 has negative refractive power. In the second lens 520, the object side surface is convex and the image side surface is concave. The third lens 530 has positive refractive power. In the third lens 530, the object side surface is convex and the image side surface is convex. The fourth lens 540 has negative refractive power. In the fourth lens 540, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the fourth lens 540. The fifth lens 550 has negative refractive power. In the fifth lens 550, the object side surface is concave and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the fifth lens 550. The sixth lens 560 has positive refractive power. In the sixth lens 560, the object side surface is convex and the image side surface is convex. Inflection points are formed on the object side surface and the image side surface of the sixth lens 560. The seventh lens 570 has negative refractive power. In the seventh lens 570, the object side surface is convex and the image side surface is concave. Inflection points are formed on the object side surface and the image side surface of the seventh lens 570.

[0119] The imaging lens system 500 may further include an optical filter 580 and an image sensor 590. The optical filter 580 is disposed between the seventh lens 570 and the image sensor 590. A stop (not shown) may be disposed between the third lens 530 and the fourth lens 540. The imaging lens system 500 has a field of view of 100.30 degrees.

[0120] The imaging lens system 500 configured as above has the following features: Fig.10 The aberration characteristics shown in Fig.10 As shown in , the imaging lens system 500 can significantly reduce spherical aberration, curvature aberration, and distortion aberration while having a field of view of 100 degrees or more. Tables 9 and 10 show the lens characteristics and aspheric values ​​of the imaging lens system 500.

[0121] Table 9

[0122]

[0123]

[0124] Table 10

[0125] Surface number r k A B C D S1 -5.2231 0.3822 0.1345 -0.0994 0.0608 0.0576 S2 -2.8853 -0.9582 0.4039 -1.1538 3.3582 -7.7188 S3 1.7518 -1.6089 0.0712 -0.9480 4.3067 -13.4321 S4 1.5055 -0.4836 -0.3193 1.3677 -12.9841 110.2421 S5 15.3543 0.0000 -0.0845 2.1836 -37.7602 407.8684 S6 -2.2274 -0.8668 -0.0035 -2.2349 21.9637 -135.2857 S7 -2.9795 1.9576 -0.2679 1.0331 -12.0087 72.5541 S8 -7.0037 25.3938 -0.0014 -0.1425 -0.8751 5.2255 S9 -1.6630 -1.6612 0.5011 -0.7543 0.6738 -0.4359 S10 -3.9101 -8.5250 -0.1240 -0.1362 0.7218 -1.6701 S11 1.2910 -1.2744 -0.1627 0.1859 -0.3038 0.2993 S12 -22.1981 0.0000 0.4858 -0.6241 0.4517 -0.2122 S13 1.5357 -3.8178 -0.2857 -0.0258 0.2127 -0.1890 S14 0.7981 -1.0247 -0.7001 0.5895 -0.4221 0.2465 Surface number E F G H J S1 -0.2569 0.4191 -0.4175 0.2768 -0.1246 S2 13.1437 -16.3401 14.7823 -9.6812 4.5291 S3 25.5617 -20.9831 -24.0562 95.3473 -135.6567 S4 -667 2798 -8203 16903 -24346 S5 -2948 14797 -52618 133335 -239007 S6 559 -1604 3262 -4739 4887 S7 -270 678 -1192 1485 -1307 S8 -13.2379 20.1932 -19.9449 12.6582 -4.6493 S9 0.7245 -1.6423 2.2771 -1.9680 1.1120 S10 2.5521 -2.5981 1.7792 -0.8233 0.2548 S11 -0.1826 0.0704 -0.0167 0.0021 0.0000 S12 0.0644 -0.0113 0.0004 0.0003 -0.0001 S13 0.1005 -0.0375 0.0102 -0.0021 0.0003 S14 -0.1110 0.0374 -0.0093 0.0017 -0.0002

[0126] Table 11 shows characteristic values ​​of the imaging lens systems according to the first example to the fifth example.

[0127] Table 11

[0128]

[0129]

[0130] In addition, the imaging lens system may have the following optical characteristics. For example, the total length TTL of the imaging lens system is determined within the range of 5.6 mm to 6.0 mm, the focal length of the imaging lens system is determined within the range of 3.0 mm to 3.5 mm, the focal length of the first lens is determined within the range of 10 mm to 22 mm, the focal length of the second lens is determined to be -18 mm or less, the focal length of the third lens is determined within the range of 3.0 mm to 4.5 mm, the focal length of the fourth lens is determined within the range of -40 mm to -7.0 mm, the focal length of the fifth lens is determined within the range of -6.0 mm to -4.0 mm, the focal length of the sixth lens is determined within the range of 1.4 mm to 3.0 mm, and the focal length of the seventh lens is determined within the range of -10 mm to -1.0 mm. In addition, the field of view (FOV) of the imaging lens system is 100 degrees or more.

[0131] Table 12 shows values ​​of conditional expressions of the imaging lens systems according to the first example to the fifth example.

[0132] Table 12

[0133]

[0134] As described above, the performance of a small-sized camera can be achieved.

[0135] Although the present disclosure includes specific examples, it will be apparent after understanding the disclosure of the present application that various changes in form and detail may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are considered to be illustrative only and not for limiting purposes. The description of the features or aspects in each example will be considered to be applicable to similar features or aspects in other examples. If the described techniques are performed in a different order, and / or if the components in the described systems, architectures, devices, or circuits are combined in different ways, and / or replaced or supplemented by other components or their equivalents, suitable results may be achieved. Therefore, the scope of the present disclosure is not limited by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are interpreted as being included in the present disclosure.

Claims

1. An imaging lens system, comprising: A first lens having positive refractive power and including a concave object-side surface; The second lens has negative refractive power; A third lens element having positive refractive power; A fourth lens element having negative refractive power; A fifth lens element having negative refractive power; a sixth lens element having positive refractive power; as well as The seventh lens has negative refractive power. Wherein, the first lens to the seventh lens are arranged in sequence from the object side toward the imaging surface, wherein at least one of the first lens to the seventh lens has an aspherical surface, Wherein, the number of lenses having refractive power in the imaging lens system is 7, wherein the imaging lens system has a focal length in the range of 3.0 mm to 3.5 mm, wherein the field of view of the imaging lens system is 100 degrees or greater, Wherein, TTL / ImgH<1.5, wherein TTL is the distance from the object side of the first lens to the imaging plane, and ImgH is the height of the imaging plane, and Wherein, D12 / D23<0.14, wherein D12 is the distance from the image side surface of the first lens to the object side surface of the second lens, and D23 is the distance from the image side surface of the second lens to the object side surface of the third lens.

2. The imaging lens system according to claim 1, wherein: The second lens has a convex object-side surface.

3. The imaging lens system according to claim 1, wherein: The third lens has a convex object-side surface.

4. The imaging lens system according to claim 1, wherein: The fourth lens has a convex object-side surface.

5. The imaging lens system according to claim 1, wherein: The fifth lens has a concave object-side surface.

6. The imaging lens system according to claim 1, wherein: The sixth lens has a convex object-side surface.

7. The imaging lens system according to claim 1, wherein: The seventh lens has a concave object-side surface.

8. An imaging lens system, comprising: A first lens having positive refractive power and including a concave object-side surface; The second lens has negative refractive power; The third lens has positive refractive power; A fourth lens element having negative refractive power; A fifth lens element having negative refractive power; a sixth lens element having positive refractive power; as well as The seventh lens has negative refractive power. Wherein, the first lens to the seventh lens are arranged in sequence from the object side toward the imaging surface, Wherein, the number of lenses having refractive power in the imaging lens system is 7, wherein the imaging lens system has a focal length in the range of 3.0 mm to 3.5 mm, wherein the field of view of the imaging lens system is 100 degrees or greater, Where, -2.0<(ImgH / (f*tan(FOV / 2))-1)*100<2.0 and TTL / ImgH<1.5, Wherein, ImgH is the height of the imaging plane, f is the focal length of the imaging lens system, FOV is the field of view of the imaging lens system, and TTL is the distance from the object side of the first lens to the imaging plane, and Wherein, D12 / D23<0.14, wherein D12 is the distance from the image side surface of the first lens to the object side surface of the second lens, and D23 is the distance from the image side surface of the second lens to the object side surface of the third lens.

9. The imaging lens system according to claim 8, wherein: The second lens has a convex object-side surface.

10. The imaging lens system according to claim 8, wherein: The third lens has a convex object-side surface.

11. The imaging lens system according to claim 8, wherein: The fourth lens has a convex object-side surface.

12. The imaging lens system according to claim 8, wherein: The fifth lens has a concave object-side surface.

13. The imaging lens system according to claim 8, wherein: The sixth lens has a convex object-side surface.

14. The imaging lens system according to claim 8, wherein: The seventh lens has a concave object-side surface.

Images