Optical imaging system

Abstract

The optical imaging system includes 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 in sequence from the object side of the optical imaging system. The first lens has positive refractive power, and the second lens has positive refractive power. At least one of the lenses has negative refractive power and a refractive index greater than 1.68.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2019-0055680 filed on May 13, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety for all purposes. Technical Field

[0003] The following description relates to an optical imaging system. Background Art

[0004] Mobile communication terminals have been provided with camera modules so as to enable video calls and image capture. In addition, as the level of camera functionality in such mobile communication terminals has gradually increased, cameras used in mobile communication terminals are gradually required to have higher levels of resolution and performance.

[0005] However, due to the trend of mobile communication terminals becoming increasingly miniaturized and lightweight, there are limitations in realizing a camera module having high resolution and high performance.

[0006] In order to solve such problems, recent camera lenses have been formed of plastic (a material lighter than glass), and the optical imaging system has been configured of five or six lenses to achieve a high level of resolution. Summary of the invention

[0007] The purpose of providing this summary is to introduce a selection of inventive concepts in a concise form, and these inventive concepts will be further described in the following detailed description. This summary is not intended to identify the key features or essential features of the subject matter claimed, nor is it intended to help determine the scope of the subject matter claimed.

[0008] An optical imaging system capable of improving aberrations and realizing high resolution.

[0009] In one general aspect, an optical imaging system includes: 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 in order from an object side of the optical imaging system, the first lens having positive refractive power, the second lens having positive refractive power, and at least one of the lenses having negative refractive power and a refractive index greater than 1.68.

[0010] At least three of the lenses may have negative refractive power and a refractive index greater than 1.66.

[0011] Among the first to seventh lenses, a refractive index of the lens having negative refractive power may be greater than a refractive index of the lens having positive refractive power.

[0012] The third lens may have negative refractive power and a refractive index greater than 1.68, and the refractive index of the third lens may be the largest among the lenses.

[0013] The optical imaging system may satisfy FOV>70°, where FOV is the field of view angle of the imaging system including the lens.

[0014] The optical imaging system may satisfy f / EPD<1.5, where f is the total focal length of the imaging system including the lens, and EPD is the entrance pupil diameter.

[0015] The optical imaging system may include an aperture stop disposed between the first lens and the second lens.

[0016] The optical imaging system may satisfy SD / TD>0.8, where SD is the optical axis distance from the aperture to the image side surface of the eighth lens, and TD is the optical axis distance from the object side surface of the first lens to the image side surface of the eighth lens.

[0017] The optical imaging system may satisfy TTL / (2×IMG HT)<0.9, where TTL is the optical axis distance from the object side of the first lens to the image capturing surface of the image sensor, and IMG HT is half the diagonal length of the image capturing surface of the image sensor.

[0018] The third lens may have negative refractive power.

[0019] The fourth lens may have positive refractive power.

[0020] The fifth lens may have negative refractive power.

[0021] The sixth lens may have positive refractive power.

[0022] The seventh lens may have positive or negative refractive power, and the eighth lens may have negative refractive power.

[0023] In another general aspect, an optical imaging system includes: 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 in order from an object side of the optical imaging system, the first lens has positive refractive power, the second lens has positive refractive power, at least four lenses from the third lens to the eighth lens have negative refractive power, and a refractive index of at least one lens of the lenses with negative refractive power is greater than 1.68.

[0024] The optical imaging system may satisfy Fno<1.5, where Fno is an F number of the imaging system including a lens.

[0025] Among the lenses, the absolute value of the focal length of the seventh lens may be the largest.

[0026] Among the lenses, the absolute value of the focal length of the eighth lens may be the smallest.

[0027] In another general aspect, an optical imaging system includes: 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 in order from an object side of the optical imaging system. At least four of the lenses have positive refractive power, and at least three of the lenses have negative refractive power, and Fno<1.5, where Fno is an F number of the imaging system including the lenses.

[0028] Other features and aspects will become apparent from the following detailed description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a diagram showing an optical imaging system according to a first example.

[0030] Figure 2 It is shown Figure 1 Graph of the aberration characteristics of the optical imaging system shown in .

[0031] Figure 3 is a diagram showing an optical imaging system according to a second example.

[0032] Figure 4 It is shown Figure 3 Graph of the aberration characteristics of the optical imaging system shown in .

[0033] Figure 5 is a diagram showing an optical imaging system according to a third example.

[0034] Figure 6 It is shown Figure 5 Graph of the aberration characteristics of the optical imaging system shown in .

[0035] Figure 7 is a diagram showing an optical imaging system according to a fourth example.

[0036] Figure 8 It is shown Figure 7 Graph of the aberration characteristics of the optical imaging system shown in .

[0037] In all drawings and detailed description, the same reference numerals refer to the same elements. For the purpose of clarity, illustration and convenience, the drawings may not be drawn to scale, and the relative sizes, proportions and depictions of elements in the drawings may be exaggerated. DETAILED DESCRIPTION

[0038] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described in this application. However, various changes, modifications and equivalents of the methods, devices and / or systems described in this application will be apparent to those of ordinary skill in the art. The order of operations described in this application is merely an example, and except for operations that must occur in a specific order, it is not limited to the order set forth in this application, but can be changed, which is apparent to those of ordinary skill in the art. In addition, for greater clarity and brevity, the description of functions and structures known to those of ordinary skill in the art may be omitted.

[0039] The features described in this application can be implemented in different forms and should not be understood as being limited to the examples described in this application. Rather, the examples described in this application are provided so that this disclosure will be thorough and complete, and the scope of this disclosure will be fully conveyed to those of ordinary skill in the art.

[0040] It should be noted that in this application, the use of the word "may" with respect to examples or embodiments, for example, with respect to what an example or embodiment may include or implement, means that there is at least one example or embodiment that includes or implements such features, and all examples and embodiments are not limited thereto.

[0041] 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, the element may be directly “on,” “connected to,” or “coupled to” the other element, or one or more other elements may be present between the element and the other element. Conversely, when an element is described as being “directly on,” “directly connected to,” or “directly coupled to” another element, there may be no other elements between the element and the other element.

[0042] 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.

[0043] Although the terms "first", "second" and "third" may be used in this application to describe various components, parts, regions, layers or parts, these components, parts, regions, layers or parts are not limited by these terms. More specifically, these terms are only used to distinguish one component, part, region, layer or part from another component, part, region, layer or part. Therefore, without departing from the teachings of the examples described in this application, the first component, first component, first region, first layer or first part mentioned in the example may also be referred to as the second component, second component, second region, second layer or second part.

[0044] Spatially relative terms such as "above", "higher", "below", and "lower" may be used in this application for descriptive convenience to describe the relationship of one element relative to another element as shown in the accompanying drawings. In addition to covering the orientations depicted in the accompanying drawings, these spatially relative terms are intended to also cover different orientations of the device in use or operation. For example, if the device in the accompanying drawings is flipped, an element described as being "above" or "higher" relative to another element will be "below" or "lower" relative to the other element. Therefore, depending on the spatial orientation of the device, the term "above" covers 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 in this application should be interpreted accordingly.

[0045] The terms used in this application 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 as well. The words "include", "comprise" and "have" illustrate the presence of the features, numbers, operations, components, elements and / or their combinations, but do not exclude the presence or addition of one or more other features, numbers, operations, components, elements and / or their combinations.

[0046] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the drawings may occur. Therefore, the examples described in the present application are not limited to the specific shapes shown in the drawings, but include variations in shapes that occur during manufacturing.

[0047] The features of the examples described in this application can be combined in various ways that will be apparent after understanding the disclosure of this application. In addition, although the examples described in this application have multiple configurations, other configurations that will be apparent after understanding the disclosure of this application are also possible.

[0048] In the drawings, for the convenience of explanation, the thickness, size and shape of the lens are slightly exaggerated. In particular, the shapes of the spherical surface or the aspherical surface shown in the drawings are only exemplary. That is, the shapes of the spherical surface or the aspherical surface are not limited to those shown in the drawings.

[0049] In this application, the first lens refers to a lens closest to an object, and the eighth lens refers to a lens closest to an image sensor.

[0050] In addition, the first surface of each lens refers to the surface of each lens closest to the object side (or object side surface), and the second surface of each lens refers to the surface of each lens closest to the image side (or image side surface). In addition, all numerical values ​​of the radius of curvature and the thickness or distance of the lens are expressed in millimeters (mm), and the field of view (FOV) is expressed in degrees.

[0051] Furthermore, in the description of the shape of each lens, a convex surface of a lens means that the paraxial region portion of the corresponding surface is convex, and a concave surface of a lens means that the paraxial region portion of the corresponding surface is concave. Therefore, even if a surface of a lens is described as convex, the edge portion of the lens may be concave. Similarly, even if a surface of a lens is described as concave, the edge portion of the lens may be convex.

[0052] The paraxial region refers to a very narrow region including the optical axis.

[0053] An optical imaging system according to various examples may include eight lenses.

[0054] For example, the optical imaging 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 in sequence from the object side. The first lens to the eighth lens are respectively spaced apart from each other by a predetermined distance along the optical axis.

[0055] However, the optical imaging system is not limited to including only eight lenses, but may include other components as necessary.

[0056] For example, the optical imaging system may further include an image sensor that converts an image of a subject incident on the image sensor into an electrical signal.

[0057] The optical imaging system may further include an infrared filter (hereinafter, “filter”) that cuts off infrared rays. The filter may be disposed between the eighth lens and the image sensor.

[0058] The optical imaging system may also include an aperture to control the amount of light.

[0059] In the optical imaging system according to various examples, the first to eighth lenses may be formed of plastic.

[0060] At least one of the first to eighth lenses may have an aspherical surface. In addition, each of the first to eighth lenses may have at least one aspherical surface.

[0061] That is, at least one of the first and second surfaces of all the lenses of the first to eighth lenses may be aspherical. The aspherical surfaces of the first to eighth lenses may be represented by the following equation 1:

[0062] Equation 1

[0063]

[0064] In Equation 1, c is the curvature of the lens (the inverse of the radius of curvature), K is the cone constant, and Y is the distance from a certain point on the aspherical surface of the lens to the optical axis. In addition, constants A to I are aspherical coefficients. In addition, Z is the distance from a certain point on the aspherical surface of the lens to the tangent plane intersecting the vertex of the aspherical surface of the lens.

[0065] The first to eighth lenses included in the optical imaging system may have positive refractive power / positive refractive power / negative refractive power / positive refractive power / negative refractive power / positive refractive power / negative refractive power in sequence from the object side. Alternatively, the first to eighth lenses may have positive refractive power / positive refractive power / negative refractive power / positive refractive power / negative refractive power / positive refractive power / positive refractive power / negative refractive power.

[0066] The optical imaging system according to each example may satisfy the following conditional expression:

[0067] Conditional expression 1: f / EPD<1.5

[0068] Conditional expression 2: SD / TD>0.8

[0069] Conditional expression 3: FOV>70°

[0070] Conditional expression 4: TTL / (2×IMG HT)<0.9

[0071] In the conditional expressions, f is the total focal length of the optical imaging system, EPD is the entrance pupil diameter, SD is the optical axis distance from the aperture to the image side surface of the eighth lens, TD is the optical axis distance from the object side surface of the first lens to the image side surface of the eighth lens, FOV is the field angle of the optical imaging system, TTL is the optical axis distance from the object side surface of the first lens to the image capturing surface of the image sensor, and IMG HT is half the diagonal length of the image capturing surface of the image sensor.

[0072] In the conditional expression, f / EPD is the F number of the optical imaging system.

[0073] The first lens has positive refractive power. The first lens may have a meniscus shape with a convex object side surface. For example, a first surface of the first lens may be convex, and a second surface of the first lens may be concave.

[0074] At least one of the first surface and the second surface of the first lens may be aspherical. For example, both surfaces of the first lens may be aspherical.

[0075] The second lens may have positive refractive power. The second lens may have a meniscus shape with a convex object side surface. For example, a first surface of the second lens may be convex, and a second surface of the second lens may be concave.

[0076] At least one of the first surface and the second surface of the second lens may be aspherical. For example, both surfaces of the second lens may be aspherical.

[0077] The third lens may have negative refractive power. The third lens may have a meniscus shape with a convex object side surface. For example, a first surface of the third lens may be convex, and a second surface of the third lens may be concave.

[0078] At least one of the first surface and the second surface of the third lens may be aspherical. For example, both surfaces of the third lens may be aspherical.

[0079] The fourth lens may have positive refractive power. Both surfaces of the fourth lens may be convex in the paraxial region. For example, the first surface and the second surface of the fourth lens may be convex in the paraxial region.

[0080] At least one inflection point may be formed on at least one of the first surface and the second surface of the fourth lens. For example, the first surface of the fourth lens may be convex in the paraxial region and become concave toward the edge of the first surface of the fourth lens. The second surface of the fourth lens may be convex in the paraxial region and become concave toward the edge of the second surface of the fourth lens.

[0081] At least one of the first surface and the second surface of the fourth lens may be aspherical. For example, both surfaces of the fourth lens may be aspherical.

[0082] The fifth lens may have negative refractive power. The fifth lens may have a meniscus shape with a convex object side surface. For example, a first surface of the fifth lens may be convex, and a second surface of the fifth lens may be concave.

[0083] At least one inflection point may be formed on at least one of the first surface and the second surface of the fifth lens. For example, the first surface of the fifth lens may be convex in the paraxial region and become concave toward the edge of the first surface of the fifth lens. The second surface of the fifth lens may be concave in the paraxial region and become convex toward the edge of the second surface of the fifth lens.

[0084] At least one of the first surface and the second surface of the fifth lens may be aspherical. For example, both surfaces of the fifth lens may be aspherical.

[0085] The sixth lens may have positive refractive power. Two surfaces of the sixth lens may be convex. For example, the first surface and the second surface of the sixth lens may be convex.

[0086] At least one inflection point may be formed on at least one of the first surface and the second surface of the sixth lens. For example, the first surface of the sixth lens may be convex in the paraxial region and become concave toward an edge of the first surface of the sixth lens.

[0087] At least one of the first surface and the second surface of the sixth lens may be aspherical. For example, both surfaces of the sixth lens may be aspherical.

[0088] The seventh lens may have positive refractive power or negative refractive power. The seventh lens may have a meniscus shape with a convex image side surface. For example, the first surface of the seventh lens may be concave in the paraxial region, and the second surface of the seventh lens may be convex in the paraxial region.

[0089] Alternatively, both surfaces of the seventh lens may be concave. For example, the first surface and the second surface of the seventh lens may be concave in the paraxial region.

[0090] Alternatively, the seventh lens may have a meniscus shape with the object-side surface being convex. For example, the first surface of the seventh lens may be convex in the paraxial region, and the second surface of the seventh lens may be concave in the paraxial region.

[0091] At least one inflection point may be formed on at least one of the first surface and the second surface of the seventh lens. For example, the first surface of the seventh lens may be concave in the paraxial region and become convex toward the edge of the first surface of the seventh lens. The second surface of the seventh lens may be convex in the paraxial region and become concave toward the edge of the second surface of the seventh lens.

[0092] At least one of the first surface and the second surface of the seventh lens may be aspherical. For example, both surfaces of the seventh lens may be aspherical.

[0093] The eighth lens may have negative refractive power. Both surfaces of the eighth lens may be concave. For example, the first surface and the second surface of the eighth lens may be concave in the paraxial region.

[0094] At least one inflection point may be formed on at least one of the first surface and the second surface of the eighth lens. For example, the first surface of the eighth lens may be concave in the paraxial region and become convex toward the edge of the first surface of the eighth lens. The second surface of the eighth lens may be concave in the paraxial region and become convex toward the edge of the second surface of the eighth lens.

[0095] At least one of the first surface and the second surface of the eighth lens may be aspherical. For example, both surfaces of the eighth lens may be aspherical.

[0096] Among the lenses having negative refractive power, at least three lenses have a refractive index greater than 1.66.

[0097] Among the lenses having negative refractive power, at least one lens has a refractive index greater than 1.68. For example, the third lens has negative refractive power, and the refractive index of the third lens is greater than 1.68. The refractive index of the third lens is greater than the refractive indexes of the other lenses.

[0098] Among the first to seventh lenses, the lens having negative refractive power may be formed to have a refractive index greater than that of the lens having positive refractive power.

[0099] That is, among the remaining lenses except the eighth lens disposed closest to the image sensor, the refractive index of the lens having negative refractive power may be greater than the refractive index of the lens having positive refractive power.

[0100] Among the first to eighth lenses, the absolute value of the focal length of the seventh lens is the largest, and the absolute value of the focal length of the eighth lens is the smallest.

[0101] In the optical imaging system configured as described above, a plurality of lenses may perform an aberration correction function to increase aberration improvement performance.

[0102] In the following, reference Figure 1 and Figure 2 An optical imaging system according to a first example is described.

[0103] The optical imaging system according to the first example 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 , and may further include a stop ST, a filter 190 and an image sensor 191 .

[0104] The lens characteristics of each lens (radius of curvature, thickness of the lens or distance between lenses, refractive index, and Abbe number) are shown in Table 1.

[0105] Table 1

[0106]

[0107] According to a first example, the total focal length f of the optical imaging system is 6.21 mm, Fno is 1.47, BFL is 0.95 mm, FOV is 74.8°, and IMG HT is 4.7 mm.

[0108] Fno is the F number of the optical imaging system, BFL is the optical axis distance from the image side surface of the eighth lens to the image capturing surface of the image sensor, FOV is the field angle of the optical imaging system, and IMG HT is half of the diagonal length of the image capturing surface of the image sensor.

[0109] In a first example, the first lens 110 may have positive refractive power, and a first surface of the first lens 110 may be convex and a second surface of the first lens 110 may be concave.

[0110] The second lens 120 may have positive refractive power, and a first surface of the second lens 120 may be convex and a second surface of the second lens 120 may be concave.

[0111] The third lens 130 may have negative refractive power, and a first surface of the third lens 130 may be convex and a second surface of the third lens 130 may be concave.

[0112] The fourth lens 140 may have positive refractive power, and the first and second surfaces of the fourth lens 140 are convex in the paraxial region.

[0113] At least one inflection point may be formed on at least one of the first surface and the second surface of the fourth lens 140. For example, the first surface of the fourth lens 140 may be convex in the paraxial region and become concave toward an edge of the first surface of the fourth lens 140. The second surface of the fourth lens 140 may be convex in the paraxial region and become concave toward an edge of the second surface of the fourth lens 140.

[0114] The fifth lens 150 may have negative refractive power, and a first surface of the fifth lens 150 may be convex in the paraxial region and a second surface of the fifth lens 150 may be concave in the paraxial region.

[0115] At least one inflection point may be formed on at least one of the first surface and the second surface of the fifth lens 150. For example, the first surface of the fifth lens 150 may be convex in the paraxial region and become concave toward an edge of the first surface of the fifth lens 150. The second surface of the fifth lens 150 may be concave in the paraxial region and become convex toward an edge of the second surface of the fifth lens 150.

[0116] The sixth lens 160 may have positive refractive power, and the first and second surfaces of the sixth lens 160 are convex in the paraxial region.

[0117] At least one inflection point may be formed on at least one of the first and second surfaces of the sixth lens 160. For example, the first surface of the sixth lens 160 may be convex in the paraxial region and become concave toward an edge of the first surface of the sixth lens 160.

[0118] The seventh lens 170 may have negative refractive power, and a first surface of the seventh lens 170 may be concave in the paraxial region and a second surface of the seventh lens 170 may be convex in the paraxial region.

[0119] At least one inflection point may be formed on at least one of the first surface and the second surface of the seventh lens 170. For example, the first surface of the seventh lens 170 may be concave in the paraxial region and become convex toward an edge of the first surface of the seventh lens 170. The second surface of the seventh lens 170 may be convex in the paraxial region and become concave toward an edge of the second surface of the seventh lens 170.

[0120] The eighth lens 180 may have negative refractive power, and the first and second surfaces of the eighth lens 180 are concave in the paraxial region.

[0121] At least one inflection point may be formed on at least one of the first surface and the second surface of the eighth lens 180. For example, the first surface of the eighth lens 180 may be concave in the paraxial region and become convex toward an edge of the first surface of the eighth lens 180. The second surface of the eighth lens 180 may be concave in the paraxial region and become convex toward an edge of the second surface of the eighth lens 180.

[0122] Each surface of the first to eighth lenses 110 to 180 may have an aspherical coefficient as shown in Table 2. For example, all object-side surfaces and image-side surfaces of the first to eighth lenses 110 to 180 may be aspherical.

[0123] The stop ST may be disposed between the first lens 110 and the second lens 120 .

[0124] Table 2

[0125] 1 2 3 4 5 6 7 8 K -0.82879 -26.3981 -0.45843 1.93822 2.62662 -3.21831 6.57E-09 3.89E-09 A 0.00324 0.00738 0.00866 0.00963 -0.01324 -0.01083 -0.01019 -0.01751 B 0.00202 -0.00725 -0.01046 -0.00799 0.00571 0.00964 -0.00154 0.00433 C -0.00266 0.00655 0.0111 0.0062 -0.01464 -0.02374 -0.00021 -0.00897 D 0.00231 -0.00508 -0.01159 -0.00766 0.01858 0.03448 -0.00327 0.00767 E -0.00118 0.00275 0.00795 0.00662 -0.01212 -0.02788 0.0043 -0.00445 F 0.00036 -0.00092 -0.00323 -0.00328 0.00456 0.01364 -0.00261 0.00162 G -6.70E-05 0.00018 0.00075 0.00091 -0.00099 -0.00401 0.00084 -0.00034 H 6.57E-06 -1.91E-05 -9.23E-05 -0.00013 0.00011 0.00066 -0.00013 3.92E-05 I -2.67E-07 8.26E-07 4.68E-06 7.86E-06 -5.47E-06 -4.62E-05 8.38E-06 -1.84E-06 9 10 11 12 13 14 15 16 K -7.31662 -43.3819 -35.9092 -1.2804 7.57E+00 5.20573 -3.51953 -0.97087 A -0.04287 -0.04579 -0.03046 0.03322 0.04203 0.02793 -0.03711 -0.0643 B 0.0121 0.02488 0.02766 -0.01502 -0.02284 -0.0144 -0.0027 0.01305 C -0.00678 -0.01846 -0.01656 0.00422 0.00513 0.00266 0.00278 -0.00211 D 0.00014 0.00905 0.00595 -0.00103 -0.00067 -0.00024 -0.00051 0.00028 E 0.00187 -0.00307 -0.0015 0.00019 4.94E-05 8.33E-06 4.94E-05 -3.04E-05 F -0.00116 0.00072 0.00027 -2.34E-05 -1.42E-06 4.64E-07 -2.81E-06 2.22E-06 G 0.00034 -0.00011 -3.65E-05 1.56E-06 -3.77E-08 -5.70E-08 9.44E-08 -1.02E-07 H -5.01E-05 9.87E-06 2.87E-06 -5.25E-08 3.45E-09 2.19E-09 -1.74E-09 2.64E-09 I 2.89E-06 -3.80E-07 -9.89E-08 6.84E-10 -6.23E-11 -3.12E-11 1.36E-11 -2.91E-11

[0126] Figure 1 The optical imaging system may have Figure 2 Aberration characteristics shown in .

[0127] In the following, reference Figure 3 and Figure 4 An optical imaging system according to a second example is described.

[0128] The optical imaging system according to the second example 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 , and may also include a stop ST, a filter 290 and an image sensor 291 .

[0129] The lens characteristics of each lens (radius of curvature, thickness of the lens or distance between lenses, refractive index, and Abbe number) are shown in Table 3.

[0130] Table 3

[0131]

[0132] According to a second example, the total focal length f of the optical imaging system is 6.12 mm, Fno is 1.37, BFL is 0.95 mm, FOV is 75.6°, and IMG HT is 4.7 mm.

[0133] The definitions of Fno, BFL, FOV, and IMG HT are the same as those in the first example.

[0134] In a second example, the first lens 210 may have positive refractive power, and a first surface of the first lens 210 may be convex and a second surface of the first lens 210 may be concave.

[0135] The second lens 220 may have positive refractive power, and a first surface of the second lens 220 may be convex and a second surface of the second lens 220 may be concave.

[0136] The third lens 230 may have negative refractive power, and a first surface of the third lens 230 may be convex and a second surface of the third lens 230 may be concave.

[0137] The fourth lens 240 may have positive refractive power, and the first and second surfaces of the fourth lens 240 are convex in the paraxial region.

[0138] At least one inflection point may be formed on at least one of the first surface and the second surface of the fourth lens 240. For example, the first surface of the fourth lens 240 may be convex in the paraxial region and become concave toward an edge of the first surface of the fourth lens 240. The second surface of the fourth lens 240 may be convex in the paraxial region and become concave toward an edge of the second surface of the fourth lens 240.

[0139] The fifth lens 250 may have negative refractive power, and a first surface of the fifth lens 250 may be convex in the paraxial region and a second surface of the fifth lens 250 may be concave in the paraxial region.

[0140] At least one inflection point may be formed on at least one of the first surface and the second surface of the fifth lens 250. For example, the first surface of the fifth lens 250 may be convex in the paraxial region and become concave toward the edge of the first surface of the fifth lens 250. The second surface of the fifth lens 250 may be concave in the paraxial region and become convex toward the edge of the second surface of the fifth lens 250.

[0141] The sixth lens 260 may have positive refractive power, and the first and second surfaces of the sixth lens 260 are convex in the paraxial region.

[0142] At least one inflection point may be formed on at least one of the first and second surfaces of the sixth lens 260. For example, the first surface of the sixth lens 260 may be convex in the paraxial region and become concave toward an edge of the first surface of the sixth lens 260.

[0143] The seventh lens 270 may have negative refractive power, and the first and second surfaces of the seventh lens 270 are concave in the paraxial region.

[0144] At least one inflection point may be formed on at least one of the first surface and the second surface of the seventh lens 270. For example, the first surface of the seventh lens 270 may be concave in the paraxial region and become convex toward the edge of the first surface of the seventh lens 270. The second surface of the seventh lens 270 may be concave in the paraxial region and become convex toward the edge of the second surface of the seventh lens 270.

[0145] The eighth lens 280 may have negative refractive power, and the first and second surfaces of the eighth lens 280 are concave in the paraxial region.

[0146] At least one inflection point may be formed on at least one of the first surface and the second surface of the eighth lens 280. For example, the first surface of the eighth lens 280 may be concave in the paraxial region and become convex toward the edge of the first surface of the eighth lens 280. The second surface of the eighth lens 280 may be concave in the paraxial region and become convex toward the edge of the second surface of the eighth lens 280.

[0147] Each surface of the first to eighth lenses 210 to 280 may have an aspheric coefficient as shown in Table 4. For example, all object-side surfaces and image-side surfaces of the first to eighth lenses 210 to 280 may be aspheric.

[0148] The stop ST may be disposed between the first lens 210 and the second lens 220 .

[0149] Table 4

[0150] 1 2 3 4 5 6 7 8 K -0.82675 -26.3981 -0.55179 1.93822 2.62662 -3.1364 0 0 A 0.00344 0.01247 0.01614 0.01575 -0.00812 -0.00707 -0.00989 -0.01892 B 0.00149 -0.0142 -0.0208 -0.01746 -0.00696 -0.0026 -0.00334 0.00718 C -0.00181 0.00833 0.01306 0.01126 0.00039 -0.00323 0.00291 -0.01259 D 0.00147 -0.00274 -0.00641 -0.00703 0.00741 0.01247 -0.00725 0.01052 E -0.00071 0.00052 0.00303 0.00431 -0.0067 -0.01223 0.00725 -0.00599 F 0.00021 -5.03E-05 -0.00117 -0.00198 0.00288 0.0064 -0.00392 0.00217 G -4.06E-05 5.58E-07 0.00029 0.00056 -0.00067 -0.00193 0.00118 -0.00046 H 4.31E-06 3.20E-07 -3.97E-05 -8.56E-05 8.12E-05 3.19E-04 -1.82E-04 5.31E-05 I -2.01E-07 -2.16E-08 2.26E-06 5.41E-06 -3.97E-06 -2.23E-05 1.11E-05 -2.53E-06 9 10 11 12 13 14 15 16 K -7.31662 -43.3819 -35.9092 -1.25885 7.57148 5.20574 -3.51953 -0.94596 A -0.04537 -0.0472 -0.0344 0.03115 0.04587 0.03085 -0.04502 -0.06997 B 0.01603 0.02689 0.03214 -0.01238 -0.02636 -0.01781 0.00058 0.01578 C -0.01145 -0.02078 -0.01895 0.00328 0.0063 0.00399 0.00202 -0.0029 D 0.00459 0.01091 0.00691 -0.00088 -0.00089 -0.00054 -0.0004 0.00043 E -0.0009 -0.00399 -0.00181 0.00019 0.00007 0.00005 0.00004 -0.00005 F -0.00011 0.00099 0.00035 -0.00002 0 0 0 0 G 0.00011 -0.00016 -0.00005 0 0 0 0 0 H -2.25E-05 1.41E-05 3.51E-06 -5.58E-08 3.08E-09 -2.64E-09 -1.18E-09 4.04E-09 I 1.54E-06 -5.37E-07 -1.16E-07 7.53E-10 -6.64E-11 2.51E-11 8.85E-12 -4.43E-11

[0151] Figure 3 The optical imaging system may have Figure 4 Aberration characteristics shown in .

[0152] In the following, reference Figure 5 and Figure 6 An optical imaging system according to a third example is described.

[0153] The optical imaging system according to the third example 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 , and may also include a stop ST, a filter 390 and an image sensor 391 .

[0154] The lens characteristics of each lens (radius of curvature, thickness of the lens or distance between lenses, refractive index, and Abbe number) are shown in Table 5.

[0155] Table 5

[0156]

[0157] According to a third example, the total focal length f of the optical imaging system is 6.10 mm, Fno is 1.35, BFL is 0.945 mm, FOV is 76.4°, and IMG HT is 4.7 mm.

[0158] The definitions of Fno, BFL, FOV, and IMG HT are the same as those in the first example.

[0159] In a third example, the first lens 310 may have positive refractive power, and a first surface of the first lens 310 may be convex and a second surface of the first lens 310 may be concave.

[0160] The second lens 320 may have positive refractive power, and a first surface of the second lens 320 may be convex and a second surface of the second lens 320 may be concave.

[0161] The third lens 330 may have negative refractive power, and a first surface of the third lens 330 may be convex and a second surface of the third lens 330 may be concave.

[0162] The fourth lens 340 may have positive refractive power, and the first and second surfaces of the fourth lens 340 are convex in the paraxial region.

[0163] At least one inflection point may be formed on at least one of the first surface and the second surface of the fourth lens 340. For example, the first surface of the fourth lens 340 may be convex in the paraxial region and become concave toward an edge of the first surface of the fourth lens 340. The second surface of the fourth lens 340 may be convex in the paraxial region and become concave toward an edge of the second surface of the fourth lens 340.

[0164] The fifth lens 350 may have negative refractive power, and a first surface of the fifth lens 350 may be convex in the paraxial region and a second surface of the fifth lens 350 may be concave in the paraxial region.

[0165] At least one inflection point may be formed on at least one of the first surface and the second surface of the fifth lens 350. For example, the first surface of the fifth lens 350 may be convex in the paraxial region and become concave toward the edge of the first surface of the fifth lens 350. The second surface of the fifth lens 350 may be concave in the paraxial region and become convex toward the edge of the second surface of the fifth lens 350.

[0166] The sixth lens 360 may have positive refractive power, and the first and second surfaces of the sixth lens 360 are convex in the paraxial region.

[0167] At least one inflection point may be formed on at least one of the first and second surfaces of the sixth lens 360. For example, the first surface of the sixth lens 360 may be convex in the paraxial region and become concave toward an edge of the first surface of the sixth lens 360.

[0168] The seventh lens 370 may have negative refractive power, and a first surface of the seventh lens 370 may be convex in the paraxial region and a second surface of the seventh lens 370 may be concave in the paraxial region.

[0169] At least one inflection point may be formed on at least one of the first surface and the second surface of the seventh lens 370. For example, the first surface of the seventh lens 370 may be convex in the paraxial region and become concave toward the edge of the first surface of the seventh lens 370. The second surface of the seventh lens 370 may be concave in the paraxial region and become convex toward the edge of the second surface of the seventh lens 370.

[0170] The eighth lens 380 may have negative refractive power, and the first and second surfaces of the eighth lens 380 are concave in the paraxial region.

[0171] At least one inflection point may be formed on at least one of the first surface and the second surface of the eighth lens 380. For example, the first surface of the eighth lens 380 may be concave in the paraxial region and become convex toward the edge of the first surface of the eighth lens 380. The second surface of the eighth lens 380 may be concave in the paraxial region and become convex toward the edge of the second surface of the eighth lens 380.

[0172] Each surface of the first to eighth lenses 310 to 380 may have an aspheric coefficient as shown in Table 6. For example, all object-side surfaces and image-side surfaces of the first to eighth lenses 310 to 380 may be aspheric.

[0173] The stop ST may be disposed between the first lens 310 and the second lens 320 .

[0174] Table 6

[0175] 1 2 3 4 5 6 7 8 K -0.80275 -26.3981 -0.62277 1.93822 2.62662 -3.07051 0 0 A 0.00323 0.01031 0.01389 0.01832 -0.00463 -0.00562 -0.00789 -0.02293 B 0.00171 -0.00455 -0.00847 -0.01403 -0.00813 -0.00323 -0.01318 0.01966 C -0.00167 -0.00431 -0.00347 0.00075 -0.00626 -0.00607 0.02252 -0.03211 D 0.00131 0.0053 0.00312 0.00128 0.01725 0.01693 -0.02835 0.02766 E -0.00068 -0.00244 0.00037 0.00145 -0.01305 -0.01443 0.02056 -0.01502 F 0.00022 0.00062 -0.00087 -0.00164 0.0051 0.00639 -0.00893 0.00508 G -0.00005 -0.00009 0.0003 0.00061 -0.00111 -0.00156 0.00227 -0.00102 H 5.14E-06 7.52E-06 -4.59E-05 -1.02E-04 1.25E-04 1.99E-04 -3.10E-04 1.12E-04 I -2.53E-07 -2.67E-07 2.64E-06 6.60E-06 -5.82E-06 -1.01E-05 1.73E-05 -5.09E-06 9 10 11 12 13 14 15 16 K -7.31662 -43.3819 -35.9092 -1.23189 7.57E+00 5.20574 -3.51953 -1.0006 A -0.05133 -0.05031 -0.03392 0.02557 0.04016 0.03375 -0.03984 -0.06765 B 0.03093 0.03382 0.03206 -0.00863 -0.02084 -0.01856 -0.00102 0.01484 C -0.03089 -0.0266 -0.01862 0.00268 0.00425 0.00411 0.00221 -0.00261 D 0.02006 0.01384 0.00672 -0.00099 -0.00048 -0.00057 -0.0004 0.00037 E -0.00899 -0.00502 -0.00179 0.00024 0.00002 0.00005 0.00004 -0.00004 F 0.00267 0.00125 0.00035 -0.00003 0 0 0 0 G -0.00048 -0.0002 -0.00005 0 0 0 0 0 H 4.75E-05 1.81E-05 3.73E-06 -8.03E-08 7.07E-09 -4.12E-09 -1.08E-09 2.92E-09 I -1.93E-06 -6.92E-07 -1.24E-07 1.15E-09 -1.08E-10 4.42E-11 7.95E-12 -3.05E-11

[0176] Figure 5 The optical imaging system may have Figure 6 Aberration characteristics shown in .

[0177] In the following, reference Figure 7 and Figure 8 An optical imaging system according to a fourth example is described.

[0178] The optical imaging system according to the fourth example 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 , and may also include a stop ST, a filter 490 and an image sensor 491 .

[0179] The lens characteristics (curvature radius, thickness of the lens or distance between lenses, refractive index, and Abbe number) of each lens are shown in Table 7.

[0180] Table 7

[0181]

[0182] According to a fourth example, the total focal length f of the optical imaging system is 6.20 mm, Fno is 1.29, BFL is 0.928 mm, FOV is 73.1°, and IMG HT is 4.7 mm.

[0183] The definitions of Fno, BFL, FOV, and IMG HT are the same as those in the first example.

[0184] In a fourth example, the first lens 410 may have positive refractive power, and a first surface of the first lens 410 may be convex and a second surface of the first lens 410 may be concave.

[0185] The second lens 420 may have positive refractive power, and a first surface of the second lens 420 may be convex and a second surface of the second lens 420 may be concave.

[0186] The third lens 430 may have negative refractive power, and a first surface of the third lens 430 may be convex and a second surface of the third lens 430 may be concave.

[0187] The fourth lens 440 may have positive refractive power, and the first and second surfaces of the fourth lens 440 are convex in the paraxial region.

[0188] At least one inflection point may be formed on at least one of the first surface and the second surface of the fourth lens 440. For example, the first surface of the fourth lens 440 may be convex in the paraxial region and become concave toward an edge of the first surface of the fourth lens 440. The second surface of the fourth lens 440 may be convex in the paraxial region and become concave toward an edge of the second surface of the fourth lens 440.

[0189] The fifth lens 450 may have negative refractive power, and a first surface of the fifth lens 450 may be convex in the paraxial region and a second surface of the fifth lens 450 may be concave in the paraxial region.

[0190] At least one inflection point may be formed on at least one of the first surface and the second surface of the fifth lens 450. For example, the first surface of the fifth lens 450 may be convex in the paraxial region and become concave toward the edge of the first surface of the fifth lens 450. The second surface of the fifth lens 450 may be concave in the paraxial region and become convex toward the edge of the second surface of the fifth lens 450.

[0191] The sixth lens 460 may have positive refractive power, and the first and second surfaces of the sixth lens 460 are convex in the paraxial region.

[0192] At least one inflection point may be formed on at least one of the first and second surfaces of the sixth lens 460. For example, the first surface of the sixth lens 460 may be convex in the paraxial region and become concave toward an edge of the first surface of the sixth lens 460.

[0193] The seventh lens 470 may have negative refractive power, and a first surface of the seventh lens 470 may be convex in the paraxial region and a second surface of the seventh lens 470 may be concave in the paraxial region.

[0194] At least one inflection point may be formed on at least one of the first surface and the second surface of the seventh lens 470. For example, the first surface of the seventh lens 470 may be convex in the paraxial region and become concave toward the edge of the first surface of the seventh lens 470. The second surface of the seventh lens 470 may be concave in the paraxial region and become convex toward the edge of the second surface of the seventh lens 470.

[0195] The eighth lens 480 may have negative refractive power, and the first and second surfaces of the eighth lens 480 are concave in the paraxial region.

[0196] At least one inflection point may be formed on at least one of the first surface and the second surface of the eighth lens 480. For example, the first surface of the eighth lens 480 may be concave in the paraxial region and become convex toward the edge of the first surface of the eighth lens 480. The second surface of the eighth lens 480 may be concave in the paraxial region and become convex toward the edge of the second surface of the eighth lens 480.

[0197] Each surface of the first to eighth lenses 410 to 480 may have an aspherical coefficient as shown in Table 8. For example, all object-side surfaces and image-side surfaces of the first to eighth lenses 410 to 480 may be aspherical.

[0198] The stop ST may be disposed between the first lens 410 and the second lens 420 .

[0199] Table 8

[0200] 1 2 3 4 5 6 7 8 K -0.80532 -26.3981 -0.62707 1.93822 2.62662 -3.06613 0 0 A 0.0028 0.00909 0.0109 0.01445 -0.00534 -0.00339 -0.00695 -0.02016 B 0.00157 -0.00368 -0.00139 -0.0035 -0.00282 -0.01006 -0.01 0.01573 C -0.00146 -0.0032 -0.01158 -0.01351 -0.00991 0.00992 0.01513 -0.0235 D 0.00102 0.00361 0.0101 0.01435 0.01591 -0.00362 -0.01791 0.01861 E -0.00046 -0.00152 -0.00399 -0.00679 -0.01013 0.00048 0.01222 -0.00935 F 0.00013 0.00036 0.00088 0.00176 0.00349 0.00003 -0.00497 0.00293 G -0.00002 -0.00005 -0.00011 -0.00025 -0.00068 0.00001 0.00118 -0.00055 H 2.38E-06 3.71E-06 7.79E-06 1.80E-05 6.97E-05 -9.12E-06 -1.49E-04 5.51E-05 I -1.05E-07 -1.22E-07 -2.32E-07 -4.54E-07 -2.94E-06 1.16E-06 7.71E-06 -2.32E-06 9 10 11 12 13 14 15 16 K -7.31662 -43.3819 -35.9092 -1.21289 7.57E+00 5.20574 -3.51953 -0.97443 A -0.04572 -0.04334 -0.02972 0.02201 0.0354 0.02975 -0.03529 -0.05931 B 0.02572 0.02495 0.02547 -0.00635 -0.01697 -0.01509 -0.00114 0.0118 C -0.02413 -0.01738 -0.01339 0.00165 0.0032 0.00308 0.00179 -0.00188 D 0.015 0.00813 0.00437 -0.00058 -0.00034 -0.0004 -0.0003 0.00024 E -0.00646 -0.00272 -0.00106 0.00013 0.00002 0.00004 0.00003 -0.00002 F 0.00183 0.00064 0.00019 -0.00002 0 0 0 0 G -0.00031 -0.0001 -0.00002 0 0 0 0 0 H 2.92E-05 8.24E-06 1.77E-06 -3.62E-08 3.54E-09 -2.16E-09 -5.91E-10 1.30E-09 I -1.12E-06 -2.96E-07 -5.42E-08 4.73E-10 -4.99E-11 2.15E-11 4.04E-12 -1.24E-11

[0201] Figure 7 The optical imaging system may have Figure 8 Aberration characteristics shown in .

[0202] According to the examples of the optical imaging system described above, the aberration improvement effect can be enhanced while achieving high resolution.

[0203] Although the present disclosure includes specific examples, it will be apparent to those skilled in the art 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 in this application should be considered only in a descriptive sense and not for limiting purposes. The description of the features or aspects in each example should be considered applicable to similar features or aspects in other examples. Suitable results may also be obtained if the described techniques are performed in a different order, and / or if the components in the described systems, architectures, devices, or circuits are replaced or supplemented in different ways and / or by other components or their equivalents. Therefore, the scope of the present disclosure should not be limited by 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 the present disclosure.

Claims

1. An optical imaging system, comprising: 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 are arranged in sequence from the object side of the optical imaging system, wherein the first lens has positive refractive power, a convex object side surface and a concave image side surface, the second lens has positive refractive power, a convex object side surface and a concave image side surface, the third lens has negative refractive power, a convex object side surface and a concave image side surface, the fourth lens has positive refractive power, a convex object side surface and a convex image side surface, the fifth lens has negative refractive power, a convex object side surface and a concave image side surface, the sixth lens has positive refractive power, a convex object side surface and a convex image side surface, and the eighth lens has negative refractive power, a concave object side surface and a concave image side surface, Wherein, the number of lenses with refractive power in the optical imaging system is eight, and Wherein, Fno<1.5, wherein Fno is the F number of the imaging system including the first lens to the eighth lens.

2. The optical imaging system according to claim 1, wherein: The seventh lens has negative refractive power, and At least three of the lenses having negative refractive power have a refractive index greater than 1.

66.

3. The optical imaging system according to claim 2, wherein: Among the first to seventh lenses, a refractive index of a lens having a negative refractive power is greater than a refractive index of a lens having a positive refractive power.

4. The optical imaging system according to claim 3, wherein: The third lens has a refractive index greater than 1.68, and Among the first to eighth lenses, the third lens has the largest refractive index.

5. The optical imaging system according to claim 1, wherein: FOV>70°, where FOV is the field of view angle of the imaging system including the first lens to the eighth lens.

6. The optical imaging system of claim 1, further comprising a stop disposed between the first lens and the second lens.

7. The optical imaging system according to claim 6, wherein: SD / TD>0.8, wherein SD is an optical axis distance from the aperture to the image side surface of the eighth lens, and TD is an optical axis distance from the object side surface of the first lens to the image side surface of the eighth lens.

8. The optical imaging system according to claim 1, wherein: TTL / (2×IMG HT)<0.9, wherein TTL is an optical axis distance from the object-side surface of the first lens to an image capturing surface of an image sensor, and IMG HT is half of a diagonal length of the image capturing surface of the image sensor.

9. The optical imaging system according to claim 1, wherein: The seventh lens element has positive or negative refractive power.

10. The optical imaging system according to claim 1, wherein: Among the first to eighth lenses, the absolute value of the focal length of the seventh lens is the largest.

11. The optical imaging system according to claim 1, wherein: Among the first to eighth lenses, the absolute value of the focal length of the eighth lens is the smallest.

12. The optical imaging system of claim 1, wherein: At least one of the lenses having negative refractive power has a refractive index greater than 1.68.

Images