Imaging lens system

Abstract

An imaging lens system includes, in order from an object side to an image plane, a first lens, a second lens having a negative refractive power, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens having a concave object side surface in a paraxial region. The imaging lens system satisfies TTL / IMGHT < 1.5, where TTL is a distance from an object side surface of the first lens to the image plane, and IMGHT is half of a diagonal length of the image plane.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2019-0152526, filed with the Korean Intellectual Property Office on November 25, 2019, the entire disclosure of which is incorporated herein by reference for all purposes. Technical Field

[0003] The following description relates to an imaging lens system comprising eight lenses. Background Technology

[0004] Small cameras can be mounted on wireless terminal devices. For example, a small camera can be mounted on each of the front and rear surfaces of a wireless terminal device. Since such small cameras can be used for various purposes, such as acquiring images of landscapes, indoor portraits, etc., they need to have performance similar to that of ordinary cameras. However, the limited size of wireless terminal devices can restrict installation space, making it difficult for small cameras to achieve high performance. Therefore, there is a need to develop an imaging lens system that can improve the performance of small cameras without increasing their size. Summary of the Invention

[0005] The summary portion of this invention is intended to provide a brief overview of the chosen inventive concepts, which will be further described in the detailed description portion below. This summary portion is not intended to identify key or essential features of the claimed subject matter, nor to help determine the scope of the claimed subject matter.

[0006] An imaging lens system is provided that can improve the performance of small cameras.

[0007] In one general aspect, the imaging lens system includes a first lens, a second lens having negative refractive power, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens having a concave object-side surface in the paraxial region, arranged sequentially in the direction from the object side to the imaging plane. The imaging lens system satisfies TTL / IMGHT < 1.5, where TTL is the distance from the object-side surface of the first lens to the imaging plane, and IMGHT is half the diagonal length of the imaging plane.

[0008] The second lens can have a concave image-side surface.

[0009] The fourth lens can have positive refractive power.

[0010] The fifth lens can have a concave image-side surface.

[0011] The sixth lens can have negative refractive power.

[0012] The seventh lens may have a positive refractive power.

[0013] The imaging lens system may satisfy 0.5 < f1 / f < 1.0, where f is the focal length of the imaging lens system and f1 is the focal length of the first lens.

[0014] The second lens may have an Abbe number less than 40.

[0015] The imaging lens system may satisfy 0.05 < TTL / FOV < 0.2, where FOV is the field angle of the imaging lens system.

[0016] The imaging lens system may satisfy 0.2 < T8 / T7 < 0.9, where T7 is the thickness of the seventh lens along the optical axis at its center and T8 is the thickness of the eighth lens along the optical axis at its center.

[0017] In another general aspect, the imaging lens system includes a first lens, a second lens with a negative refractive power, a third lens, a fourth lens, a fifth lens, a sixth lens with a concave image side, a seventh lens, and an eighth lens with a concave object side, which are sequentially arranged in the direction from the object side to the imaging surface.

[0018] The F-number of the imaging lens system may be 1.7 or less.

[0019] The imaging lens system may satisfy -4.0 < f2 / f1 < -2.0, where f1 is the focal length of the first lens and f2 is the focal length of the second lens.

[0020] The imaging lens system may satisfy 0.2 < f2 / f3 < 0.5, where f2 is the focal length of the second lens and f3 is the focal length of the third lens.

[0021] The imaging lens system may satisfy -5.0 < f6 / f7 < -2.0, where f6 is the focal length of the sixth lens and f7 is the focal length of the seventh lens.

[0022] The imaging lens system may satisfy -3.0 < f7 / f8 < -1.0, where f7 is the focal length of the seventh lens and f8 is the focal length of the eighth lens.

[0023] In another general aspect, the imaging lens system includes, sequentially arranged in the direction from the object side to the imaging plane, a first lens with positive refractive power, a second lens with negative refractive power, a third lens with negative refractive power, a fourth lens with refractive power, a fifth lens with refractive power, a sixth lens with negative refractive power, a seventh lens with positive refractive power, and an eighth lens with negative refractive power. The imaging lens system satisfies TTL / IMGHT < 1.5, where TTL is the distance from the object side of the first lens to the imaging plane, and IMGHT is half the diagonal length of the imaging plane.

[0024] The first through seventh lenses can be meniscus lenses, and the eighth lens can be a biconcave lens.

[0025] The first lens may be thicker than each of the other lenses along the optical axis.

[0026] The second lens can be thinner than each of the other lenses along the optical axis.

[0027] Other features and aspects will become apparent from the following detailed description, the accompanying drawings, and the appended claims. Attached Figure Description

[0028] Figure 1 This is a diagram illustrating a first example of an imaging lens system.

[0029] Figure 2 yes Figure 1 The aberration curves of the imaging lens system are shown.

[0030] Figure 3 This is a diagram illustrating a second example of an imaging lens system.

[0031] Figure 4 yes Figure 3 The aberration curves of the imaging lens system are shown.

[0032] Figure 5 This is a diagram illustrating a third example of an imaging lens system.

[0033] Figure 6 yes Figure 5 The aberration curves of the imaging lens system are shown.

[0034] Figure 7 This is a diagram illustrating a fourth example of an imaging lens system.

[0035] Figure 8 yes Figure 7 The aberration curves of the imaging lens system are shown.

[0036] Figure 9 This is a diagram illustrating the fifth example of an imaging lens system.

[0037] Figure 10 yes Figure 9 The aberration curves of the imaging lens system are shown.

[0038] Throughout the accompanying drawings and detailed embodiments, the same reference numerals refer to the same elements. For purposes of clarity, illustration, and convenience, the drawings may not be drawn to scale, and the relative dimensions, scale, and depiction of elements in the drawings may be exaggerated. Detailed Implementation

[0039] The following detailed embodiments are provided to help readers gain a comprehensive understanding of the methods, apparatus, and / or systems described in this application. However, various changes, modifications, and equivalents to the methods, apparatus, and / or systems described in this application will be readily apparent to those skilled in the art. The sequence of operations described in this application is merely illustrative, and is not limited to the order set forth in this application, except for operations that must occur in a specific order, and can be varied, as will be readily apparent to those skilled in the art. Furthermore, for clarity and brevity, descriptions of functions and structures well-known to those skilled in the art may be omitted.

[0040] The features described in this application may be implemented in various forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0041] It should be noted that in this application, the term "may" is used in relation to examples or implementations, such as with regard to what an example or implementation may include or implement, meaning that there exists at least one example or implementation that includes or implements such features, and that all examples and implementations are not limited thereto.

[0042] Throughout this specification, when an element such as a layer, region, or substrate is described as being "on," "connected to," or "attached to" another element, the element may be directly "on," directly "connected to," or directly "attached to" the other element, or there may be one or more other elements between the element and the other element. Conversely, when an element is described as being "directly on," "directly connected to," or "directly attached to" another element, there may be no other elements between the element and the other element.

[0043] As used in this application, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0044] Although terms such as “first,” “second,” and “third” may be used in this application to describe various components, parts, regions, layers, or portions, these components, parts, regions, layers, or portions are not limited by these terms. Rather, these terms are used only to distinguish one component, part, region, layer, or portion from another. Therefore, without departing from the teachings of the examples described in this application, the first component, first part, first region, first layer, or first portion mentioned in these examples may also be referred to as a second component, second part, second region, second layer, or second portion.

[0045] Spatial relative terms such as “above,” “above,” “below,” and “below” may be used in this application for descriptive convenience to describe the relationship of one element relative to another, as shown in the accompanying drawings. In addition to covering the orientation depicted in the drawings, these spatial relative terms are intended to also cover different orientations of the device in use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “above” another element would be located “below” or “below” that other element. Thus, depending on the spatial orientation of the device, the term “above” covers both orientations of “above” and “below”. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relative terms used in this application should be interpreted accordingly.

[0046] The terminology used in this application is for describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the articles “a,” “an,” and “the” are intended to include the plural form as well. The terms “comprising,” “including,” and “having” indicate the presence of the stated features, numbers, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, components, elements, and / or combinations thereof.

[0047] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described in this application are not limited to the specific shapes shown in the accompanying drawings, but include shape variations that may occur during manufacturing.

[0048] The features of the examples described in this application can be combined in various ways that will become apparent after understanding the disclosure of this application. Furthermore, although the examples described in this application have multiple configurations, other configurations that will become apparent after understanding the disclosure of this application are also possible.

[0049] The accompanying drawings may not be drawn to scale, and for clarity, illustration, and convenience, the relative dimensions, scale, and depiction of elements in the drawings may be exaggerated.

[0050] In this example, the first lens refers to the lens closest to the object (or subject), and the eighth lens refers to the lens closest to the imaging plane (or image sensor). In this example, units for radius of curvature, thickness, TTL (distance from the object-side surface of the first lens to the imaging plane), 2IMGHT (diagonal length of the imaging plane), and focal length are expressed in millimeters (mm). FOV is expressed in degrees (°).

[0051] Lens thickness, inter-lens spacing, and TTL (Time to Light) refer to the distance along the optical axis. Furthermore, in the description of lens shape, a convex surface indicates that the optical axis region of that surface is convex, and a concave surface indicates that the optical axis region of that surface is concave. Therefore, even when describing a lens as having a convex surface, the lens edge can be concave. Similarly, even when describing a lens as having a concave surface, the lens edge can be convex.

[0052] An imaging lens system may include eight lenses. For example, an imaging lens system may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged sequentially from the object side. The first to eighth lenses may be arranged with a predetermined interval between them. For example, the image-side and object-side surfaces of adjacent lenses do not contact each other in the paraxial region. Therefore, even when the image-side surface of one lens in the figure contacts the object-side surface of another lens, the image-side and object-side surfaces of the two lenses are not actually in contact with each other.

[0053] The first lens may have refractive power. One surface of the first lens may be convex. For example, the first lens may have a convex object-side surface. The first lens may include an aspherical surface. For example, both surfaces of the first lens may be aspherical. The first lens may be formed of a material with high light transmittance and excellent processability. For example, the first lens may be made of a plastic material. The first lens may have a predetermined refractive index. For example, the refractive index of the first lens may be less than 1.6. The first lens may have a predetermined Abbe number. For example, the Abbe number of the first lens may be 50 or greater. The first lens may have a predetermined focal length. For example, the focal length of the first lens may be from 4.0 mm to 6.8 mm.

[0054] The second lens may have refractive power. For example, the second lens may have negative refractive power. One surface of the second lens may be concave. For example, the second lens may have a concave image-side surface. The second lens may include an aspherical surface. For example, both surfaces of the second lens may be aspherical. The second lens may be formed of a material with high light transmittance and excellent processability. For example, the second lens may be made of a plastic material. The second lens may have a predetermined refractive index. For example, the refractive index of the second lens may be 1.6 or greater. The second lens may have a predetermined Abbe number. For example, the Abbe number of the second lens may be less than 23. The second lens may have a predetermined focal length. For example, the focal length of the second lens may be from -20 mm to -10 mm.

[0055] The third lens may have refractive power. One surface of the third lens may be convex. For example, the third lens may have a convex object-side surface. The third lens may include an aspherical surface. For example, two surfaces of the third lens may be aspherical. The third lens may be formed of a material with high light transmittance and excellent processability. For example, the third lens may be made of plastic material. The third lens may have a refractive index greater than that of the first lens. For example, the refractive index of the third lens may be 1.6 or greater. The third lens may have a predetermined Abbe number. For example, the Abbe number of the third lens may be less than 23. The third lens may have a predetermined focal length. For example, the focal length of the third lens may be from -65mm to -30mm.

[0056] The fourth lens may have refractive power. One surface of the fourth lens may be convex. For example, the fourth lens may have a convex object-side surface. The fourth lens may include an aspherical surface. For example, two surfaces of the fourth lens may be aspherical. The fourth lens may be formed from a material with high light transmittance and excellent processability. For example, the fourth lens may be made of plastic material. The fourth lens may have a refractive index lower than that of the third lens. For example, the refractive index of the fourth lens may be less than 1.6. The fourth lens may have a predetermined Abbe number. For example, the Abbe number of the fourth lens may be greater than that of the third lens. The fourth lens may have a predetermined focal length. For example, the focal length of the fourth lens may be less than -100 mm or 30 mm or greater.

[0057] The fifth lens may have refractive power. One surface of the fifth lens may be concave. For example, the fifth lens may have a concave image-side surface. The fifth lens may have a shape with a point of inflection. For example, at least one of the object-side and image-side surfaces of the fifth lens may have a point of inflection. The fifth lens may include an aspherical surface. For example, both surfaces of the fifth lens may be aspherical. The fifth lens may be formed of a material with high light transmittance and excellent processability. For example, the fifth lens may be made of a plastic material. The fifth lens may have a predetermined refractive index. For example, the fifth lens may have a refractive index lower than that of the third lens. The fifth lens may have a predetermined Abbe number. For example, the Abbe number of the fifth lens may be greater than that of the third lens. The fifth lens may have a predetermined focal length. For example, the focal length of the fifth lens may be -50 mm or less or 30 mm or more.

[0058] The sixth lens may have refractive power. One surface of the sixth lens may be convex. For example, the sixth lens may have a convex object-side surface. The sixth lens may have a shape with a point of inflection. For example, at least one of the object-side surface and the image-side surface of the sixth lens may have a point of inflection. The sixth lens may include an aspherical surface. For example, both surfaces of the sixth lens may be aspherical. The sixth lens may be formed of a material with high light transmittance and excellent processability. For example, the sixth lens may be made of a plastic material. The sixth lens may have a predetermined refractive index. For example, the refractive index of the sixth lens may be greater than or equal to the refractive index of the fifth lens. The sixth lens may have a predetermined Abbe number. For example, the Abbe number of the sixth lens may be 25 or greater and less than 40. The sixth lens may have a predetermined focal length. For example, the focal length of the sixth lens may be from -38 mm to -10 mm.

[0059] The seventh lens may have refractive power. One surface of the seventh lens may be convex. For example, the seventh lens may have a convex object-side surface. The seventh lens may have a shape with a point of inflection. For example, at least one of the object-side surface and the image-side surface of the seventh lens may have a point of inflection. The seventh lens may include an aspherical surface. For example, both surfaces of the seventh lens may be aspherical. The seventh lens may be formed of a material with high light transmittance and excellent processability. For example, the seventh lens may be made of a plastic material. The seventh lens may have a predetermined refractive index. For example, the refractive index of the seventh lens may be less than that of the sixth lens. The seventh lens may have an Abbe number greater than that of the sixth lens. For example, the Abbe number of the seventh lens may be 50 or greater. The seventh lens may have a predetermined focal length. For example, the focal length of the seventh lens may be from 3.6 mm to 7.4 mm.

[0060] The eighth lens may have refractive power. At least one surface of the eighth lens may be concave. For example, the eighth lens may have a concave image-side surface in the paraxial region. The eighth lens may have a shape with a point of inflection. For example, at least one of the object-side and image-side surfaces of the eighth lens may have a point of inflection. The eighth lens may include aspherical surfaces. For example, both surfaces of the eighth lens may be aspherical. The eighth lens may be formed of a material with high light transmittance and excellent processability. For example, the eighth lens may be made of a plastic material. The eighth lens may have a predetermined refractive index. For example, the refractive index of the eighth lens may be less than that of the sixth lens. The eighth lens may have an Abbe number greater than that of the sixth lens. For example, the Abbe number of the eighth lens may be 50 or greater. The eighth lens may have a predetermined focal length. For example, the focal length of the eighth lens may be from -6.2 mm to -3.1 mm.

[0061] In an imaging lens system, the first lens can be the thickest lens. For example, the thickness of the first lens along the optical axis at its center can be greater than the thickness of the other lenses (the second to the eighth lenses) along the optical axis at their respective centers.

[0062] In an imaging lens system, the second lens can be the thinnest lens. For example, the thickness of the second lens along the optical axis at its center can be less than the thickness of the other lenses (the first lens and the third to eighth lenses) along the optical axis at their respective centers.

[0063] Each of the first through eighth lenses may include an aspherical surface. The aspherical surface of each of the first through eighth lenses can be represented by Equation 1 below:

[0064] [Equation 1]

[0065]

[0066] In Equation 1, "c" is the reciprocal of the radius of curvature of each lens, "k" is the conic constant, "r" is the distance from a point on the aspherical surface of the lens to the optical axis, "A to J" are aspherical constants, and "Z" (or SAG) is the distance from a point on the aspherical surface to the vertex of the aspherical surface in the direction of the optical axis.

[0067] The imaging lens system may also include a filter, an image sensor, and an aperture. The filter may be positioned between the eighth lens and the image sensor. The filter may be configured to block light of a specific wavelength. For example, the filter may block infrared wavelengths. The image sensor may form an imaging surface. For example, the surface of the image sensor may form an imaging surface. The aperture may be arranged to adjust the amount of light incident on the lens. For example, the aperture may be positioned between the second and third lenses.

[0068] The imaging lens system can have a predetermined focal length. For example, the focal length f of the imaging lens system can be from 5.6 mm to 7.0 mm. The imaging lens system can have a relatively large imaging surface to achieve high resolution. For example, the diagonal length (2 IMGHT) of the imaging surface of the imaging lens system can be from 10 mm to 14 mm.

[0069] An imaging lens system can satisfy one or more of the following conditional expressions:

[0070] TTL / IMGHT < 1.5

[0071] 0.05 <TTL / FOV<0.2

[0072] 0.2 <T8 / T7<0.9

[0073] F-number ≤ 1.7

[0074] 78°≤FOV≤85°

[0075] 0.5 <f1 / f<1.0

[0076] -4.0 <f2 / f1<-2.0

[0077] 0.2 <f2 / f3<0.5

[0078] -5.0 <f6 / f7<-2.0

[0079] -3.0 <f7 / f8<-1.0

[0080] In the conditional expression, TTL is the distance from the object side of the first lens to the imaging plane, IMGHT is half the diagonal length of the imaging plane, T7 is the thickness of the seventh lens along the optical axis at its center, T8 is the thickness of the eighth lens along the optical axis at its center, FOV is the field of view of the imaging lens system, f is the focal length of the imaging lens system, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, and f8 is the focal length of the eighth lens.

[0081] Imaging lens systems can also satisfy one or more of the following conditional expressions:

[0082] 0.4 <f1 / f7<1.2

[0083] -1.4 <f1 / f8<-0.4

[0084] 18 < (V2 + V3) / 2 < 22

[0085] V2<40

[0086] V3 <V6<V7

[0087] T5 <T4

[0088] 2.0 < (R11 + R12) / (R11 - R12) < 5.0

[0089] 0.72 <DL1L4 / DL5L8<0.82

[0090] 1.06 <f / IMGHT<1.12

[0091] In the above conditional expressions, V2 is the Abbe number of the second lens, V3 is the Abbe number of the third lens, V6 is the Abbe number of the sixth lens, V7 is the Abbe number of the seventh lens, T4 is the thickness of the fourth lens along the optical axis at its center, T5 is the thickness of the fifth lens along the optical axis at its center, R11 is the radius of curvature of the object-side surface of the sixth lens, R12 is the radius of curvature of the image-side surface of the sixth lens, DL1L4 is the distance from the object-side surface of the first lens to the image-side surface of the fourth lens, and DL5L8 is the distance from the object-side surface of the fifth lens to the image-side surface of the eighth lens.

[0092] Imaging lens systems can also satisfy one or more of the following conditional expressions:

[0093] F-number ≤ 1.64

[0094] 0.4 < |f3 / f5| < 1.6

[0095] 2.0 < (R5 + R6) / (R5 - R6) < 4.0

[0096] -2.0 < (R13 + R14) / (R13 - R14) < -0.8

[0097] 1.0 <f / f7<1.3

[0098] In the above conditional expressions, R5 is the radius of curvature of the object side of the third lens, R6 is the radius of curvature of the image side of the third lens, R13 is the radius of curvature of the object side of the seventh lens, and R14 is the radius of curvature of the image side of the seventh lens.

[0099] In the following description, various examples of imaging lens systems will be described.

[0100] Reference Figure 1 A first example describing an imaging lens system.

[0101] 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, a seventh lens 170, and an eighth lens 180.

[0102] The first lens 110 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 120 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 130 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 140 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The fifth lens 150 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the fifth lens 150. The sixth lens 160 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the sixth lens 160. The seventh lens 170 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the seventh lens 170. The eighth lens 180 may have negative refractive power, and a concave object-side surface and a concave image-side surface. A recurve point may be formed on at least one of the object-side surface and the image-side surface of the eighth lens 180.

[0103] The imaging lens system 100 may further include a filter IF, an image sensor IMG, and an aperture ST. The filter IF may be disposed between the eighth lens 180 and the image sensor IMG. The image sensor IMG may provide a surface on which light refracted by the first lens 110 to the eighth lens 180 is formed. One surface of the image sensor IMG may be approximately the same size as the imaging surface. For example, the diagonal length of the imaging surface (2IMGHT) refers to the diagonal length of the image sensor IMG, and the height of the imaging surface may refer to the distance from the center to the edge of the optical axis of the image sensor IMG. The aperture ST may be disposed between the second lens 120 and the third lens 130.

[0104] Tables 1 and 2 list the lens characteristics and aspherical values ​​of the imaging lens system 100. Figure 2 It is the aberration curve of the imaging lens system 100 configured as described above.

[0105] Table 1

[0106]

[0107] Table 2

[0108]

[0109] Reference Figure 3 A second example describing an imaging lens system.

[0110] 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, a seventh lens 270, and an eighth lens 280.

[0111] The first lens 210 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 220 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 230 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 240 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The fifth lens 250 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the fifth lens 250. The sixth lens 260 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the sixth lens 260. The seventh lens 270 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the seventh lens 270. The eighth lens 280 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. A recurve point may be formed on at least one of the object-side surface and the image-side surface of the eighth lens 280.

[0112] The imaging lens system 200 may further include a filter IF, an image sensor IMG, and an aperture ST. The filter IF may be disposed between the eighth lens 280 and the image sensor IMG. The image sensor IMG may provide a surface on which light refracted by the first lens 210 to the eighth lens 280 is formed. One surface of the image sensor IMG may be approximately the same size as the imaging surface. For example, the diagonal length of the imaging surface (2IMGHT) refers to the diagonal length of the image sensor IMG, and the height of the imaging surface may refer to the distance from the center to the edge of the optical axis of the image sensor IMG. The aperture ST may be disposed between the second lens 220 and the third lens 230.

[0113] Tables 3 and 4 list the lens characteristics and aspherical values ​​of the imaging lens system 200. Figure 4 This is the aberration curve of the imaging lens system 200 configured as described above.

[0114] Table 3

[0115]

[0116]

[0117] Table 4

[0118] Face number K A B C D E F G H J S1 -0.977501 -0.003935 0.03566 -0.06648 0.07812 -0.05719 0.02357 -0.001832 -0.003927 0.002605 S2 24.256772 -0.01734 0.02382 -0.04735 0.09105 -0.1273 0.1247 -0.08725 0.04424 -0.01632 S3 16.447043 -0.04114 0.1252 -0.3314 0.5847 -0.6813 0.5346 -0.2841 0.09972 -0.02093 S4 2.4777825 -0.02548 0.1177 -0.3338 0.515 -0.3284 -0.2047 0.6032 -0.5729 0.3107 S5 0 0.0001756 -0.08569 0.3416 -0.9226 1.758 -2.428 2.459 -1.829 0.9952 S6 56.350823 -0.01711 0.02414 -0.09787 0.228 -0.3404 0.3182 -0.173 0.03554 0.01898 S7 98.884228 -0.03447 0.2124 -1.059 3.234 -6.491 8.929 -8.669 6.038 -3.03 S8 -99.00005 -0.03892 0.08133 -0.01505 -0.6266 2.045 -3.46 3.728 -2.737 1.404 S9 0 -0.03305 0.006005 -0.09955 0.3424 -0.6687 0.8536 -0.7539 0.4727 -0.2123 S10 0 -0.04115 0.02906 -0.06185 0.089 -0.09332 0.07136 -0.03976 0.01616 -0.004776 S11 0 -0.08603 0.09214 -0.08082 0.05511 -0.03092 0.01465 -0.005795 0.001809 -0.00042 S12 -39.38114 -0.1047 0.1 -0.07676 0.0443 -0.01861 0.005745 -0.001373 0.0002715 -4.57E-05 S13 -7.365153 -0.02249 0.01129 -0.00247 -0.002451 0.00202 -0.000725 0.0001571 -2.25E-05 2.215E-06 S14 23.383791 0.01202 -0.007542 0.007938 -0.006811 0.003202 -0.000929 0.0001797 -2.41E-05 2.286E-06 S15 -1.492134 -0.07336 0.04525 -0.0173 0.003788 -0.000412 2.16E-06 5.752E-06 -8.72E-07 7.101E-08 S16 -19.10332 -0.06043 0.03583 -0.01475 0.004065 -0.000781 0.0001088 -1.12E-05 8.63E-07 -4.94E-08

[0119] Reference Figure 5 A third example describing an imaging lens system.

[0120] 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, a seventh lens 370, and an eighth lens 380.

[0121] The first lens 310 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 320 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 330 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 340 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The fifth lens 350 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the fifth lens 350. The sixth lens 360 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the sixth lens 360. The seventh lens 370 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the seventh lens 370. The eighth lens 380 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. A recurve point may be formed on at least one of the object-side surface and the image-side surface of the eighth lens 380.

[0122] The imaging lens system 300 may further include a filter IF, an image sensor IMG, and an aperture ST. The filter IF may be disposed between the eighth lens 380 and the image sensor IMG. The image sensor IMG may provide a surface on which light refracted by the first lens 310 to the eighth lens 380 is formed. One surface of the image sensor IMG may be approximately the same size as the imaging surface. For example, the diagonal length of the imaging surface (2IMGHT) refers to the diagonal length of the image sensor IMG, and the height of the imaging surface may refer to the distance from the center to the edge of the optical axis of the image sensor IMG. The aperture ST may be disposed between the second lens 320 and the third lens 330.

[0123] Tables 5 and 6 list the lens characteristics and aspherical values ​​of the imaging lens system 300. Figure 6 This is the aberration curve of the imaging lens system 300 configured as described above.

[0124] Table 5

[0125]

[0126]

[0127] Table 6

[0128] Face number K A B C D E F G H J S1 -1.021828 -0.01896 0.1021 -0.2305 0.3375 -0.3375 0.239 -0.1221 0.04541 -0.01224 S2 27.483091 -0.02125 0.02647 -0.04209 0.08433 -0.1286 0.1344 -0.09851 0.05187 -0.01979 S3 16.571645 -0.0269 0.02934 -0.02785 0.005501 0.06759 -0.1621 0.1991 -0.1548 0.08107 S4 2.329664 -0.008104 0.01857 -0.07846 0.2349 -0.4188 0.4574 -0.2903 0.0682 0.04808 S5 0 0.03542 -0.3975 1.734 -4.822 9.088 -12.06 11.52 -8.02 4.072 S6 95.620843 -0.04713 0.2007 -0.809 2.045 -3.463 4.085 -3.434 2.081 -0.9096 S7 92.803604 -0.04517 0.2372 -1.015 2.742 -4.991 6.357 -5.802 3.841 -1.847 S8 19.623148 -0.0422 0.1464 -0.5006 1.076 -1.54 1.523 -1.066 0.5322 -0.1886 S9 0 -0.03346 0.01336 -0.1054 0.32 -0.589 0.7273 -0.6276 0.385 -0.1686 S10 0 -0.03637 0.04988 -0.1559 0.2794 -0.3299 0.2711 -0.1595 0.06818 -0.02119 S11 0 -0.05656 0.03784 -0.02001 0.003531 0.003559 -0.003956 0.00219 -0.000802 0.000204 S12 -37.93685 -0.06085 0.01424 0.01542 -0.02468 0.01805 -0.00854 0.002828 -0.000672 0.0001149 S13 -9.92841 -0.006148 -0.01069 0.01178 -0.008163 0.003492 -0.000994 0.000197 -2.78E-05 2.817E-06 S14 46.8868 0.02276 -0.0168 0.01054 -0.005761 0.002195 -0.000576 0.0001064 -1.41E-05 1.345E-06 S15 -1.893815 -0.07156 0.03583 -0.01332 0.003704 -0.000717 9.637E-05 -9.14E-06 6.184E-07 -2.98E-08 S16 -25.29874 -0.04909 0.02346 -0.008608 0.002275 -0.000431 5.922E-05 -5.95E-06 4.389E-07 -2.37E-08

[0129] Reference Figure 7 The fourth example describes an imaging lens system.

[0130] 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, a seventh lens 470, and an eighth lens 480.

[0131] The first lens 410 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 420 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 430 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 440 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The fifth lens 450 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the fifth lens 450. The sixth lens 460 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the sixth lens 460. The seventh lens 470 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the seventh lens 470. The eighth lens 480 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. A recurve point may be formed on at least one of the object-side surface and the image-side surface of the eighth lens 480.

[0132] The imaging lens system 400 may further include a filter IF, an image sensor IMG, and an aperture ST. The filter IF may be disposed between the eighth lens 480 and the image sensor IMG. The image sensor IMG may provide a surface on which light refracted by the first lens 410 to the eighth lens 480 is formed. One surface of the image sensor IMG may be approximately the same size as the imaging surface. For example, the diagonal length of the imaging surface (2IMGHT) refers to the diagonal length of the image sensor IMG, and the height of the imaging surface may refer to the distance from the center to the edge of the optical axis of the image sensor IMG. The aperture ST may be disposed between the second lens 420 and the third lens 430.

[0133] Tables 7 and 8 list the lens characteristics and aspherical values ​​of the imaging lens system 400. Figure 8 This is the aberration curve of the imaging lens system 400 configured as described above.

[0134] Table 7

[0135]

[0136] Table 8

[0137]

[0138]

[0139] Reference Figure 9 The fifth example describing an imaging lens system.

[0140] 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, a seventh lens 570, and an eighth lens 580.

[0141] The first lens 510 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 520 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 530 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 540 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fifth lens 550 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the fifth lens 550. The sixth lens 560 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the sixth lens 560. The seventh lens 570 may have positive refractive power and may have a convex object-side surface and a concave image-side surface. A curvature point may be formed on at least one of the object-side surface and image-side surface of the seventh lens 570. The eighth lens 580 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. A recurve point may be formed on at least one of the object-side surface and the image-side surface of the eighth lens 580.

[0142] The imaging lens system 500 may further include a filter IF, an image sensor IMG, and an aperture ST. The filter IF may be disposed between the eighth lens 580 and the image sensor IMG. The image sensor IMG may provide a surface on which light refracted by the first lens 510 to the eighth lens 580 is formed. One surface of the image sensor IMG may be approximately the same size as the imaging surface. For example, the diagonal length of the imaging surface (2IMGHT) refers to the diagonal length of the image sensor IMG, and the height of the imaging surface may refer to the distance from the center to the edge of the optical axis of the image sensor IMG. The aperture ST may be disposed between the second lens 520 and the third lens 530.

[0143] Tables 9 and 10 list the lens characteristics and aspherical values ​​of the imaging lens system 500. Figure 10 This is the aberration curve of the imaging lens system 500 configured as described above.

[0144] Table 9

[0145]

[0146] Table 10

[0147] Face number K A B C D E F G H J S1 -1.028837 -0.02409 0.1446 -0.3787 0.6314 -0.7099 0.5594 -0.3161 0.1294 -0.03841 S2 27.139418 -0.01912 0.01984 -0.01858 0.03317 -0.06354 0.0825 -0.07178 0.04322 -0.01831 S3 16.56626 -0.03611 0.08325 -0.1934 0.3467 -0.4275 0.3499 -0.18 0.04606 0.005663 S4 2.3619195 -0.006635 -0.02015 0.1695 -0.6002 1.364 -2.14 2.391 -1.928 1.124 S5 0 0.03964 -0.4617 2.104 -6.062 11.76 -16 15.64 -11.12 5.753 S6 98.932938 -0.05194 0.2269 -0.8855 2.193 -3.673 4.319 -3.642 2.225 -0.9845 S7 92.330151 -0.03483 0.1489 -0.6154 1.616 -2.873 3.577 -3.193 2.069 -0.9745 S8 -98.98639 -0.0416 0.134 -0.4795 1.094 -1.666 1.759 -1.327 0.7252 -0.2882 S9 0 -0.03919 0.02504 -0.1109 0.3044 -0.5401 0.652 -0.5516 0.3318 -0.1424 S10 0 -0.03933 0.05215 -0.1519 0.2678 -0.3165 0.2629 -0.1574 0.06872 -0.0219 S11 0 -0.06085 0.0609 -0.05644 0.0367 -0.01688 0.005064 -0.000733 -0.0001 8.014E-05 S12 -36.84334 -0.08749 0.07584 -0.05801 0.03358 -0.01451 0.004584 -0.001033 0.0001598 -1.57E-05 S13 -9.956325 -0.01164 6.404E-05 0.000979 -0.002315 0.001509 -0.000532 0.0001191 -1.81E-05 1.903E-06 S14 -84.33771 0.02575 -0.01685 0.007841 -0.00402 0.001651 -0.000474 9.442E-05 -1.33E-05 1.33E-06 S15 -1.549727 -0.06796 0.03522 -0.01412 0.004139 -0.000819 0.0001098 -1.01E-05 6.502E-07 -2.85E-08 S16 -23.9777 -0.04939 0.02417 -0.009403 0.002602 -0.000508 0.0000709 -7.18E-06 5.316E-07 -2.87E-08

[0148] Tables 11 and 12 list the optical characteristic values ​​and conditional expressions for the imaging lens systems of the first through fifth examples. In Table 11, BFL refers to the distance from the image-side surface of the eighth lens to the imaging plane.

[0149] Table 11

[0150]

[0151]

[0152] Table 12

[0153]

[0154] Based on the above example, the performance of small cameras can be improved.

[0155] While this disclosure includes specific examples, it will be apparent upon understanding the disclosure of this application that various changes in form and detail may be made to these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein should be understood in a descriptive sense only and not for limiting purposes. The description of features or aspects in each example should be understood as applicable to similar features or aspects in other examples. Appropriate results may still be achieved if the described techniques are performed in a different order, and / or if components in the described system, architecture, device, or circuit are combined in different ways and / or replaced or supplemented by other components or their equivalents. Therefore, the scope of this disclosure is not limited by the specific embodiments but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents should be understood to be included in this disclosure.

Claims

1. An imaging lens system, comprising: The first lens has positive refractive power; The second lens has negative refractive power; The third lens has negative refractive power; The fourth lens has positive refractive power; The fifth lens has refractive power; The sixth lens has negative refractive power; The seventh lens has positive refractive power; as well as The eighth lens has negative refractive power and a concave object-side surface in the paraxial region. The first lens to the eighth lens are arranged sequentially from the object side to the imaging plane. The imaging lens system has a total of eight lenses. The first lens is thicker along the optical axis than each of the other lenses. Where -1.4 < f1 / f8 < -0.4, f1 is the focal length of the first lens, and f8 is the focal length of the eighth lens. Wherein, 1.0 < f / f7 < 1.3, where f is the focal length of the imaging lens system, and f7 is the focal length of the seventh lens. Where -5.0 < f6 / f7 < -2.0, and f6 is the focal length of the sixth lens.

2. The imaging lens system according to claim 1, wherein, The first lens has a concave image-side surface.

3. The imaging lens system according to claim 1, wherein, The second lens has a concave image-side surface.

4. The imaging lens system according to claim 1, wherein, The third lens has a concave image-side surface.

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

6. The imaging lens system according to claim 1, wherein, The sixth lens has a concave image-side surface.

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

8. An imaging lens system, comprising: The first lens has positive refractive power; The second lens has negative refractive power; The third lens has negative refractive power; The fourth lens has positive refractive power; The fifth lens has refractive power; The sixth lens has negative refractive power; The seventh lens has positive refractive power; as well as The eighth lens has negative refractive power and a concave object-side surface in the paraxial region. The first lens to the eighth lens are arranged sequentially from the object side to the imaging plane. The imaging lens system has a total of eight lenses. The second lens is thinner along the optical axis than each of the other lenses. Where -1.4 < f1 / f8 < -0.4, f1 is the focal length of the first lens, and f8 is the focal length of the eighth lens. Wherein, 1.0 < f / f7 < 1.3, where f is the focal length of the imaging lens system, and f7 is the focal length of the seventh lens. Where -5.0 < f6 / f7 < -2.0, and f6 is the focal length of the sixth lens.

9. The imaging lens system according to claim 8, wherein, 1.3015 ≤ TTL / IMGHT < 1.5, where TTL is the distance from the object side of the first lens to the imaging surface, and IMGHT is half the diagonal length of the imaging surface.

10. The imaging lens system according to claim 8, wherein, 0.5 < f1 / f < 1.

0.

11. The imaging lens system according to claim 8, wherein, 0.4 < f1 / f7 < 1.

2.

12. The imaging lens system according to claim 8, wherein, -4.0 < f2 / f1 < -2.0, where f2 is the focal length of the second lens.

13. The imaging lens system according to claim 8, wherein, 0.2 < f2 / f3 < 0.5, where f2 is the focal length of the second lens and f3 is the focal length of the third lens.

14. The imaging lens system according to claim 8, wherein, -3.0 < f7 / f8 < -1.

0.

15. The imaging lens system according to claim 8, wherein, -2.0 < (R13+R14) / (R13-R14) < -0.8, where R13 is the radius of curvature of the object side of the seventh lens and R14 is the radius of curvature of the image side of the seventh lens.

Images