Optical image capturing system

Abstract

An optical imaging system is provided. The optical imaging system includes a first lens, a second lens, a third lens, a fourth lens having a positive refractive power, a fifth lens, a sixth lens, a seventh lens having a positive refractive power, an eighth lens, and a ninth lens, where the first to ninth lenses are disposed in order from an object side, and where the conditional expression 1.0 lt; f number lt; 1.4 and 1.30 < = TTL / flt; tTL is a distance on the optical axis from the object-side surface to the image-side surface of the first lens, and f is a focal length of the optical imaging system.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10 - 2024 - 0039671, filed on March 22, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. Technical field

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

[0004] Optical systems that can output bright images have been implemented in mobile devices. The brightness of an image can be related to the F - number of the optical system, and the smaller the F - number, the brighter the presented image. To reduce the F - number, the size of the entrance pupil can be increased, but as the size of the entrance pupil increases, aberration may occur. Summary of the invention

[0005] The Summary of the Invention section is provided to introduce, in a brief form, selections of concepts that will be further described in the Detailed Description section below. The Summary of the Invention section is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to help determine the scope of the claimed subject matter.

[0006] In general, an optical imaging system includes a first lens, a second lens, a third lens, a fourth lens having positive refractive power, a fifth lens, a sixth lens, a seventh lens having positive refractive power, an eighth lens, and a ninth lens, wherein the first lens to the ninth lens are sequentially arranged from the object side, and wherein the condition expressions 1.0 < F - number < 1.4 and 1.30 ≤ TTL / f < 1.40 are satisfied, where TTL is the distance on the optical axis from the object surface of the first lens to the image plane, and f is the focal length of the optical imaging system.

[0007] Both the image surface of the third lens and the object surface of the fourth lens can be concave.

[0008] The fifth lens can have a concave object surface.

[0009] The sixth lens can have a concave image surface.

[0010] The seventh lens and the eighth lens can include an inflection point on at least one of the object surface and the image surface.

[0011] The eighth lens can have a convex image surface.

[0012] The first lens to the ninth lens can include three or more lenses having a refractive index equal to or greater than 1.60.

[0013] It can satisfy the conditional expression 0.70 ≤ TTL / (2×IMG HT) < 0.80, where IMG HT is half of the diagonal length of the image plane.

[0014] In general, 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, an eighth lens, and a ninth lens sequentially arranged from the object side, where the seventh lens has a positive refractive power, and where the eighth lens has a convex image side surface.

[0015] The second lens, the third lens, and the sixth lens can have a refractive index equal to or greater than 1.60.

[0016] The seventh lens and the eighth lens can include an inflection point on at least one of the object side surface and the image side surface.

[0017] The fourth lens and the fifth lens can have a positive refractive power.

[0018] It can satisfy the conditional expression 1.0 < F-number < 1.4.

[0019] The sixth lens can have a negative refractive power and a concave image side surface.

[0020] The third lens can have a positive refractive power.

[0021] The sixth lens can have a convex object side surface.

[0022] It can satisfy the conditional expression 1.30 ≤ TTL / f < 1.40, where TTL is the distance on the optical axis from the object side surface of the first lens to the image plane, and f is the focal length of the optical imaging system.

[0023] It can satisfy the conditional expression 0.70 ≤ TTL / (2×IMG HT) < 0.80, where TTL is the distance on the optical axis from the object side surface of the first lens to the image plane, and 2×IMG HT is the diagonal length of the image plane.

[0024] Based on the accompanying drawings and the following detailed description, other features and aspects will be apparent. Description of the Drawings

[0025] Figure 1 is a configuration diagram showing an exemplary optical imaging system according to the first embodiment.

[0026] Figure 2 is a graph showing the aberration characteristics of an exemplary optical imaging system according to the first embodiment.

[0027] Figure 3 is a configuration diagram showing an exemplary optical imaging system according to the second embodiment.

[0028] Figure 4 is a graph showing aberration characteristics of an exemplary optical imaging system according to the second embodiment.

[0029] Figure 5 is a configuration diagram showing an exemplary optical imaging system according to the third embodiment.

[0030] Figure 6 is a graph showing aberration characteristics of an exemplary optical imaging system according to the third embodiment.

[0031] Figure 7 is a configuration diagram showing an exemplary optical imaging system according to a fourth embodiment.

[0032] Figure 8 is a graph showing aberration characteristics of an exemplary optical imaging system according to the fourth embodiment.

[0033] Throughout the drawings and detailed description, unless otherwise described, 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 sizes, proportions, and descriptions of elements in the drawings may be exaggerated. DETAILED DESCRIPTION

[0034] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the method, device and / or system described herein. However, various changes, modifications and equivalents of the method, device and / or system described herein will be apparent after understanding the disclosure of the application. For example, the order in the operation described herein and / or the order of the operation described herein are merely examples, and except for the order and / or the sequence of operations in the operation that must occur in a specific sequence, are not limited to the order set forth in this article, but can be changed, which will be apparent after understanding the disclosure of the application. As another example, except for at least a portion of the order and / or the sequence of operations in the operation that must occur in a sequence (e.g., a specific sequence), the order in the sequence of operations and / or the operation can be performed in parallel. In addition, for greater clarity and brevity, the description of features known after understanding the disclosure of the application can be omitted.

[0035] Although terms such as "first," "second," and "third," or A, B, (a), (b), etc., may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Each of these terms is not intended to define, for example, the importance, sequence, or order of the corresponding member, component, region, layer, or portion, but is merely intended to distinguish the corresponding member, component, region, layer, or portion from other members, components, regions, layers, or portions. Thus, without departing from the teachings of the examples described herein, a first member, first component, first region, first layer, or first portion mentioned in these examples may also be referred to as a second member, second component, second region, second layer, or second portion.

[0036] Throughout this specification, when a component, element, or layer is described as being “on,” “connected to,” “coupled to,” or “engaged to” another component, element, or layer, it may be directly “on,” directly “connected to,” “coupled to,” or “engaged to” another component, element, or layer (e.g., in contact with another component, element, or layer), or one or more other components, elements, or layers may reasonably be present between the component, element, or layer and the other component, element, or layer. When a component, element, or layer is described as being “directly on,” “directly connected to,” “directly coupled to,” or “directly engaged to” another component, element, or layer, there are no other components, elements, or layers between the component, element, or layer and the other component, element, or layer. Similarly, expressions such as “between” and “directly between,” as well as “adjacent” and “directly adjacent,” may also be interpreted as described above.

[0037] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the terms "a", "an" and "the" are intended to also include plural forms. As non-limiting examples, the terms "comprise", "include" and "have" illustrate the presence of the described features, quantities, operations, components, elements and / or their combinations, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements and / or their combinations, or the presence of alternative features, quantities, operations, components, elements and / or their combinations. In addition, although an embodiment can set forth the terms "comprise", "include" and "have" to illustrate the presence of the described features, quantities, operations, components, elements and / or their combinations, other embodiments may exist in which one or more of the described features, quantities, operations, components, elements and / or their combinations are not present.

[0038] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items. The phrases "at least one of A, B, and C," etc. are intended to have a disjunctive meaning, and these phrases "at least one of A, B, and C," etc. also include examples in which one or more of A, B, and C can be present (e.g., any combination of one or more of A, B, and C), unless the corresponding description and implementation require that the enumeration (e.g., "at least one of A, B, and C") be interpreted as having a conjunctive meaning.

[0039] The features described herein may be embodied in different forms and should not be construed as being limited to the examples described herein. On the contrary, the examples described herein are provided merely to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application. In this article, the use of the wording "may" with respect to an example or embodiment (e.g., with respect to what an example or embodiment may include or implement) means that there is at least one example or embodiment in which such a feature is included or implemented, and all examples or embodiments are not limited thereto. The phrases "example" or "implementation" used herein have the same meaning (e.g., the phrase "in one example" has the same meaning as "in one embodiment", and "in one or more examples" has the same meaning as "in one or more embodiments").

[0040] One or more examples may provide an optical imaging system with a low F-number and a thin thickness.

[0041] In one or more embodiments, the units of the values ​​of the radius of curvature, thickness, distance, focal length, IMG HT (1 / 2 of the diagonal length of the image plane), and the semi-aperture of the lens may be millimeters (mm), and the unit of the field of view (FOV) may be degrees (°). In addition, the thickness of the lens and the distance between lenses may refer to the thickness and distance on the optical axis.

[0042] In one or more embodiments, the object side may refer to a side where an object is disposed, and the image side may refer to a side where an image plane (ie, an image sensor) on which an image is formed is disposed.

[0043] In the descriptions related to the shapes of the lenses of the embodiments, a convex surface may mean that the surface's paraxial region (narrow region near the optical axis) is convex, and a concave surface may mean that the surface's paraxial region is concave. Therefore, even when one lens surface is described as having a convex shape, the edge of the lens may be concave. Similarly, even when one lens surface is described as having a concave shape, the edge of the lens may be convex.

[0044] An optical imaging system according to one or more embodiments may be implemented in a camera of a mobile device. The mobile device may be any type of portable electronic device including but not limited to a smart phone.

[0045] According to one or more embodiments, the optical imaging system may include nine lenses. 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, an eighth lens, and a ninth lens sequentially arranged from the object side. The first lens to the ninth lens may each be disposed at a certain distance from an adjacent lens.

[0046] According to one or more embodiments, the optical imaging system may include plastic lenses. For example, at least a part of the first lens to the ninth lens may be configured as a plastic material, and preferably, the first lens to the ninth lens may be configured as a plastic material.

[0047] According to one or more embodiments, the optical imaging system may include aspherical lenses. For example, at least one of the object side surface and the image side surface of the first lens to the ninth lens may be aspherical, and preferably, both the object side surface and the image side surface of the first lens to the ninth lens may be aspherical. The aspherical surface of the lens may be represented by Equation 1 below.

[0048] Equation 1:

[0049]

[0050] In Equation 1, c is the reciprocal of the radius of curvature of the lens, K is the conic constant, Y is the distance from an arbitrary point on the aspherical surface to the optical axis, A - H, J, and L - P are the aspherical constants from the 4th order to the 30th order in sequence, and Z is the distance from an arbitrary point on the aspherical surface to the vertex of the aspherical surface in the optical axis direction.

[0051] According to one or more embodiments, the optical imaging system may further include an infrared cut-off filter, an image sensor, and an aperture. In one or more embodiments, the infrared cut-off filter may be disposed between the ninth lens and the image sensor to block infrared light in the light incident on the image sensor through the ninth lens. Additionally, in one or more embodiments, the aperture may be disposed between the third lens and the fourth lens and may adjust the amount of light incident on the lens.

[0052] According to one or more embodiments, the optical imaging system may satisfy one or more of the following conditional expressions:

[0053] (1) 1.0 < F-number < 1.4

[0054] (2) 1.30 ≤ TTL / f < 1.40

[0055] (3) 0.70 ≤ TTL / (2×IMG HT) < 0.80

[0056] In the conditional expression, TTL is the distance from the object side surface of the first lens to the image plane on the optical axis, f is the focal length of the optical imaging system, and 2×IMG HT is the diagonal length of the image plane.

[0057] Conditional Expression (1) may be related to the brightness characteristics of the optical imaging system according to one or more embodiments. The optical imaging system according to one or more embodiments may be implemented as a bright optical system by satisfying Conditional Expression (1).

[0058] Conditional expressions (2) and (3) may be related to miniaturization and thinning of the optical imaging system according to one or more embodiments. In particular, the optical imaging system according to one or more embodiments may have a low F-number and may be miniaturized and thinned, which is relatively difficult.

[0059] The optical imaging system according to one or more embodiments may further satisfy at least one of Conditional Expression (2) and Conditional Expression (3) while satisfying Conditional Expression (1).

[0060] In addition, the optical imaging system according to one or more embodiments may satisfy one or more of the conditional expressions shown below.

[0061] (4) 1.0 < f1 / f < 1.5

[0062] (5) -5 < f2 / f < -2

[0063] (6) 20 < |f3 / f|

[0064] (7) 1 < f4 / f < 5

[0065] (8) 6 < f5 / f < 12

[0066] (9) -5 < f6 / f < -2

[0067] (10) 6 < f7 / f

[0068] (11) 0 <f8 / f < 1.5

[0069] (12) -2 < f9 / f < 0

[0070] (13) BFL / f < 0.18

[0071] (14) 0.1 < F - number / IMG HT < 0.5

[0072] (15) 2 < T1 / T9 < 4

[0073] (16) 1.7 < TTL / ΣCT < 1.9

[0074] (17) 2.8 < TTL / ΣAT < 3.2

[0075] In the conditional expressions, 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, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, f8 is the focal length of the eighth lens, and f9 is the focal length of the ninth lens. In addition, BFL is the distance on the optical axis from the image side of the ninth lens to the image plane, T1 is the thickness of the first lens on the optical axis, T9 is the thickness of the ninth lens on the optical axis, ΣCT is the sum of the thicknesses of the first lens to the ninth lens on the optical axis, and ΣAT is the sum of the distances of the first lens to the ninth lens on the optical axis.

[0076] Hereinafter, an optical imaging system according to one or more embodiments may be described.

[0077] First embodiment

[0078] Figure 1 is a configuration diagram showing an exemplary optical imaging system according to the first embodiment. Figure 2 is a graph showing the aberration characteristics of an exemplary optical imaging system according to the first embodiment.

[0079] The optical imaging system 100 according to the first embodiment 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, an eighth lens 180, and a ninth lens 190.

[0080] The first lens 110 may have a positive refractive power, its object side may be convex, and its image side may be concave. The first lens 110 may have a refractive index of 1.55 or less, and its Abbe number may be 50 or greater. The first lens 110 may be formed of a plastic material. Both surfaces of the first lens 110 may be aspherical.

[0081] The second lens 120 may have negative refractive power, its object-side surface may be convex, and its image-side surface may be concave. The refractive index of the second lens 120 may be 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. The second lens 120 may be formed of a plastic material. Both surfaces of the second lens 120 may be aspherical.

[0082] The third lens 130 may have positive refractive power, its object-side surface may be convex, and its image-side surface may be concave. The refractive index of the third lens 130 may be 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. The third lens 130 may be formed of a plastic material. Both surfaces of the third lens 130 may be aspherical.

[0083] The fourth lens 140 may have positive refractive power, its object-side surface may be concave, and its image-side surface may be convex. The fourth lens 140 may have a refractive index of 1.55 or greater and less than 1.60, and its Abbe number may be 30 or greater and less than 50. The fourth lens 140 may be formed of a plastic material. Both surfaces of the fourth lens 140 may be aspherical.

[0084] The fifth lens 150 may have positive refractive power, its object-side surface may be concave, and its image-side surface may be convex. The fifth lens 150 may have a refractive index less than 1.6, and its Abbe number may be 50 or greater. The fifth lens 150 may be formed of a plastic material. Both surfaces of the fifth lens 150 may be aspherical.

[0085] The sixth lens 160 may have negative refractive power, its object-side surface may be convex, and its image-side surface may be concave. The refractive index of the sixth lens 160 may be 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. The sixth lens 160 may be formed of a plastic material. Both surfaces of the sixth lens 160 may be aspherical.

[0086] The seventh lens 170 may have positive refractive power, its object-side surface may be convex, and its image-side surface may be concave. The refractive index of the seventh lens 170 may be 1.55 or greater and less than 1.60, and its Abbe number may be 30 or greater and less than 50. The seventh lens 170 may be formed of a plastic material. Both surfaces of the seventh lens 170 may be aspherical. The seventh lens 170 may include two or more inflection points on at least one of the object-side surface and the image-side surface (and preferably on both the object-side surface and the image-side surface).

[0087] The eighth lens 180 may have positive refractive power, and both its object-side and image-side surfaces may be convex. The eighth lens 180 may have a refractive index of 1.55 or less and an Abbe number of 50 or greater. The eighth lens 180 may be formed of a plastic material. Both surfaces of the eighth lens 180 may be aspherical. The eighth lens 180 may include two or more inflection points on either the object-side or image-side surface (and preferably on the object-side surface).

[0088] Ninth lens element 190 may have negative refractive power, and both its object-side and image-side surfaces may be concave. Ninth lens element 190 may have a refractive index of 1.55 or less, and an Abbe number of 50 or greater. Ninth lens element 190 may be formed of a plastic material. Both surfaces of ninth lens element 190 may be aspherical.

[0089] The image sensor S may be disposed on the image side of the ninth lens 190 , and the infrared cut filter F may be disposed between the ninth lens 190 and the image sensor S.

[0090] According to the first embodiment, the second lens 120, the third lens 130, and the sixth lens 160 may be configured as high-refractive-index lenses having a refractive index of 1.60 or greater, thereby reducing the sweep angle and thereby reducing flare.

[0091] Tables 1 and 2 below may list lens characteristics and aspheric surface values ​​of the exemplary optical imaging system 100 according to the first embodiment.

[0092] Table 1

[0093] surface Radius of curvature Thickness / distance Refractive index Abbe number Effective radius 1 3.5803 1.1158 1.546 55.99 2.414 2 21.4321 0.0829 2.338 3 8.5769 0.2500 1.689 18.15 2.271 4 5.3930 0.3728 2.142 5 21.5067 0.2501 1.689 18.15 2.109 6 (aperture) 24.9633 0.4764 2.014 7 -59.7181 0.3765 1.571 37.40 2.033 8 -13.4432 0.0893 2.196 9 -12.4481 0.6837 1.546 55.99 2.263 10 -8.9727 0.1298 2.339 11 534.6378 0.2500 1.689 18.15 2.394 12 15.0624 0.5129 2.588 13 6.9149 0.5498 1.571 37.40 2.991 14 6.9876 0.3459 3.230 15 4.5879 0.8269 1.546 55.99 3.410 16 -7.1721 0.9677 3.694 17 -6.6181 0.5000 1.546 55.99 4.367 18 3.2704 0.2634 5.384 19 infinity 0.2100 1.519 64.20 5.866 20 infinity 0.6940 5.936 21 infinity 0.0060 6.339

[0094] Table 2

[0095]

[0096]

[0097] Second embodiment

[0098] Figure 3 is a configuration diagram showing an exemplary optical imaging system according to the second embodiment. Figure 4 is a graph showing aberration characteristics of an exemplary optical imaging system according to the second embodiment.

[0099] The optical imaging system 200 according to the second embodiment 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 , an eighth lens 280 and a ninth lens 290 .

[0100] The first lens 210 may have positive refractive power, its object-side surface may be convex, and its image-side surface may be concave. The refractive index of the first lens 210 may be 1.55 or less, and its Abbe number may be 50 or greater. The first lens 210 may be formed of a plastic material. Both surfaces of the first lens 210 may be aspherical.

[0101] The second lens 220 may have negative refractive power, its object-side surface may be convex, and its image-side surface may be concave. The second lens 220 may have a refractive index of 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. The second lens 220 may be formed of a plastic material. Both surfaces of the second lens 220 may be aspherical.

[0102] The third lens 230 may have negative refractive power, its object-side surface may be convex, and its image-side surface may be concave. The third lens 230 may have a refractive index of 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. The third lens 230 may be formed of a plastic material. Both surfaces of the third lens 230 may be aspherical.

[0103] The fourth lens 240 may have positive refractive power, its object-side surface may be concave, and its image-side surface may be convex. The fourth lens 240 may have a refractive index of 1.55 or greater and less than 1.60, and its Abbe number may be 30 or greater and less than 50. The fourth lens 240 may be formed of a plastic material. Both surfaces of the fourth lens 240 may be aspherical.

[0104] The fifth lens 250 may have positive refractive power, its object-side surface may be concave, and its image-side surface may be convex. The fifth lens 250 may have a refractive index less than 1.6 and an Abbe number of 50 or greater. The fifth lens 250 may be formed of a plastic material. Both surfaces of the fifth lens 250 may be aspherical.

[0105] The sixth lens 260 may have negative refractive power, and both its object-side and image-side surfaces may be concave. The refractive index of the sixth lens 260 may be 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. The sixth lens 260 may be formed of a plastic material. Both surfaces of the sixth lens 260 may be aspherical.

[0106] The seventh lens 270 may have positive refractive power, its object-side surface may be convex, and its image-side surface may be concave. The refractive index of the seventh lens 270 may be 1.55 or greater and less than 1.60, and its Abbe number may be 30 or greater and less than 50. The seventh lens 270 may be formed of a plastic material. Both surfaces of the seventh lens 270 may be aspherical. The seventh lens 270 may include two or more inflection points on at least one of the object-side surface and the image-side surface (and preferably on both the object-side surface and the image-side surface).

[0107] The eighth lens 280 may have positive refractive power, and both its object-side and image-side surfaces may be convex. The eighth lens 280 may have a refractive index of 1.55 or less and an Abbe number of 50 or greater. The eighth lens 280 may be formed of a plastic material. Both surfaces of the eighth lens 280 may be aspherical. The eighth lens 280 may include two or more inflection points on either the object-side or image-side surface (and preferably on the object-side surface).

[0108] Ninth lens element 290 may have negative refractive power, and both its object-side and image-side surfaces may be concave. Ninth lens element 290 may have a refractive index of 1.55 or less and an Abbe number of 50 or greater. Ninth lens element 290 may be formed of a plastic material. Both surfaces of ninth lens element 290 may be aspherical.

[0109] The image sensor S may be disposed on the image side of the ninth lens 290 , and the infrared cut filter F may be disposed between the ninth lens 290 and the image sensor S.

[0110] According to the second embodiment, the second lens 220, the third lens 230, and the sixth lens 260 may be configured as high-refractive-index lenses having a refractive index of 1.60 or greater, thereby reducing the sweep angle and thereby reducing flare.

[0111] Tables 3 and 4 below may list lens characteristics and aspheric surface values ​​of an exemplary optical imaging system 200 according to the second embodiment.

[0112] Table 3

[0113]

[0114]

[0115] Table 4

[0116]

[0117]

[0118] Third embodiment

[0119] Figure 5 is a configuration diagram showing an exemplary optical imaging system according to the third embodiment. Figure 6 is a graph showing aberration characteristics of an exemplary optical imaging system according to the third embodiment.

[0120] The optical imaging system 300 according to the third embodiment 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 , an eighth lens 380 and a ninth lens 390 .

[0121] The first lens 310 may have positive refractive power, its object-side surface may be convex, and its image-side surface may be concave. The first lens 310 may have a refractive index of 1.55 or less, and its Abbe number may be 50 or greater. The first lens 310 may be formed of a plastic material. Both surfaces of the first lens 310 may be aspherical.

[0122] The second lens 320 may have negative refractive power, its object-side surface may be convex, and its image-side surface may be concave. The second lens 320 may have a refractive index of 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. The second lens 320 may be formed of a plastic material. Both surfaces of the second lens 320 may be aspherical.

[0123] The third lens 330 may have negative refractive power, its object-side surface may be convex, and its image-side surface may be concave. The third lens 330 may have a refractive index of 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. The third lens 330 may be formed of a plastic material. Both surfaces of the third lens 330 may be aspherical.

[0124] The fourth lens 340 may have positive refractive power, its object-side surface may be concave, and its image-side surface may be convex. The fourth lens 340 may have a refractive index of 1.55 or greater and less than 1.60, and its Abbe number may be 30 or greater and less than 50. The fourth lens 340 may be formed of a plastic material. Both surfaces of the fourth lens 340 may be aspherical.

[0125] The fifth lens 350 may have positive refractive power, its object-side surface may be concave, and its image-side surface may be convex. The fifth lens 350 may have a refractive index less than 1.6 and an Abbe number of 50 or greater. The fifth lens 350 may be formed of a plastic material. Both surfaces of the fifth lens 350 may be aspherical.

[0126] The sixth lens 360 may have negative refractive power, and both its object-side and image-side surfaces may be concave. The refractive index of the sixth lens 360 may be 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. The sixth lens 360 may be formed of a plastic material. Both surfaces of the sixth lens 360 may be aspherical.

[0127] The seventh lens 370 may have positive refractive power, its object-side surface may be convex, and its image-side surface may be concave. The refractive index of the seventh lens 370 may be 1.55 or greater and less than 1.60, and its Abbe number may be 30 or greater and less than 50. The seventh lens 370 may be formed of a plastic material. Both surfaces of the seventh lens 370 may be aspherical. The seventh lens 370 may include two or more inflection points on at least one of the object-side surface and the image-side surface (preferably on both surfaces).

[0128] The eighth lens 380 may have positive refractive power, and both its object-side and image-side surfaces may be convex. The eighth lens 380 may have a refractive index of 1.55 or less and an Abbe number of 50 or greater. The eighth lens 380 may be formed of a plastic material. Both surfaces of the eighth lens 380 may be aspherical. The eighth lens 380 may include two or more inflection points on either the object-side or image-side surface (and preferably on the object-side surface).

[0129] Ninth lens element 390 may have negative refractive power, and both its object-side and image-side surfaces may be concave. Ninth lens element 390 may have a refractive index of 1.55 or less and an Abbe number of 50 or greater. Ninth lens element 390 may be formed of a plastic material. Both surfaces of ninth lens element 390 may be aspherical.

[0130] The image sensor S may be disposed on the image side of the ninth lens 390 , and the infrared cut filter F may be disposed between the ninth lens 390 and the image sensor S.

[0131] According to the third embodiment, the second lens 320, the third lens 330, and the sixth lens 360 may be configured as high-refractive-index lenses having a refractive index of 1.60 or greater, thereby reducing the sweep angle and thereby reducing flare.

[0132] Tables 5 and 6 below may list lens characteristics and aspheric surface values ​​of the optical imaging system 300 according to the third embodiment.

[0133] Table 5

[0134]

[0135]

[0136] Table 6

[0137]

[0138]

[0139] Fourth embodiment

[0140] Figure 7 is a configuration diagram showing an exemplary optical imaging system according to a fourth embodiment. Figure 8 is a graph showing aberration characteristics of an exemplary optical imaging system according to the fourth embodiment.

[0141] The optical imaging system 400 according to the fourth embodiment 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 , an eighth lens 480 and a ninth lens 490 .

[0142] The first lens 410 may have positive refractive power, its object-side surface may be convex, and its image-side surface may be concave. The first lens 410 may have a refractive index of 1.55 or less, and its Abbe number may be 50 or greater. The first lens 410 may be formed of a plastic material. Both surfaces of the first lens 410 may be aspherical.

[0143] Second lens 420 may have negative refractive power, its object-side surface may be convex, and its image-side surface may be concave. Second lens 420 may have a refractive index of 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. Second lens 420 may be formed of a plastic material. Both surfaces of second lens 420 may be aspherical.

[0144] The third lens 430 may have negative refractive power, its object-side surface may be convex, and its image-side surface may be concave. The third lens 430 may have a refractive index of 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. The third lens 430 may be formed of a plastic material. Both surfaces of the third lens 430 may be aspherical.

[0145] The fourth lens 440 may have positive refractive power, its object-side surface may be concave, and its image-side surface may be convex. The fourth lens 440 may have a refractive index of 1.55 or greater and less than 1.60, and its Abbe number may be 30 or greater and less than 50. The fourth lens 440 may be formed of a plastic material. Both surfaces of the fourth lens 440 may be aspherical.

[0146] The fifth lens 450 may have positive refractive power, its object-side surface may be concave, and its image-side surface may be convex. The fifth lens 450 may have a refractive index less than 1.6 and an Abbe number of 50 or greater. The fifth lens 450 may be formed of a plastic material. Both surfaces of the fifth lens 450 may be aspherical.

[0147] The sixth lens 460 may have negative refractive power, and both its object-side and image-side surfaces may be concave. The refractive index of the sixth lens 460 may be 1.60 or greater, preferably 1.65 or greater, and its Abbe number may be less than 20. The sixth lens 460 may be formed of a plastic material. Both surfaces of the sixth lens 460 may be aspherical.

[0148] The seventh lens 470 may have positive refractive power, its object-side surface may be convex, and its image-side surface may be concave. The refractive index of the seventh lens 470 may be 1.55 or greater and less than 1.60, and its Abbe number may be 30 or greater and less than 50. The seventh lens 470 may be formed of a plastic material. Both surfaces of the seventh lens 470 may be aspherical. The seventh lens 470 may include two or more inflection points on at least one of the object-side surface and the image-side surface (preferably on both surfaces).

[0149] The eighth lens 480 may have positive refractive power, and both its object-side and image-side surfaces may be convex. The eighth lens 480 may have a refractive index of 1.55 or greater and less than 1.60, and an Abbe number of 30 or greater and less than 50. The eighth lens 480 may be formed of a plastic material. Both surfaces of the eighth lens 480 may be aspherical. The eighth lens 480 may include two or more inflection points on either the object-side or image-side surface (and preferably on the object-side surface).

[0150] The ninth lens element 490 may have negative refractive power, and both its object-side and image-side surfaces may be concave. The refractive index of the ninth lens element 490 may be 1.55 or less, and its Abbe number may be 50 or greater. The ninth lens element 490 may be formed of a plastic material. Both surfaces of the ninth lens element 490 may be aspherical.

[0151] The image sensor S may be disposed on the image side of the ninth lens 490 , and the infrared cut filter F may be disposed between the ninth lens 490 and the image sensor S.

[0152] According to the fourth embodiment, the second lens 420, the third lens 430, and the sixth lens 460 may be configured as high-refractive-index lenses having a refractive index of 1.60 or greater, thereby reducing the sweep angle and thereby reducing flare.

[0153] Tables 7 and 8 below may list lens characteristics and aspheric surface values ​​of the optical imaging system 400 according to the fourth embodiment.

[0154] Table 7

[0155]

[0156]

[0157] Table 8

[0158]

[0159]

[0160] Table 9 below may list optical parameters and physical parameters of the optical imaging systems according to the first to fourth embodiments.

[0161] Table 9

[0162] First embodiment Second embodiment Third embodiment Fourth embodiment f 6.6073 6.5641 6.6868 6.6134 f1 7.6977 7.4393 7.2890 7.3179 f2 -21.7784 -21.3072 -19.4014 -19.6236 f3 218.9187 -193.0388 -1456.9921 -1600.4698 f4 30.3069 24.7243 27.2156 27.2182 f5 55.0025 68.8522 75.2340 75.2795 f6 -22.4946 -21.4344 -19.5103 -19.5843 f7 310.7942 70.3422 49.7154 50.1928 f8 5.2520 5.8923 5.8753 5.8833 f9 -3.9360 -4.3290 -4.2391 -4.3320 TTL 8.9538 8.8426 8.9660 8.9430 BFL 1.173 1.149 1.139 1.129 F-number 1.3735 1.3658 1.2868 1.2781 FOV 86.92 86.63 81.93 80.42 IMG HT 6.329 6.329 5.920 5.920 T1 1.1158 1.1105 1.3267 1.3386 T9 0.5000 0.5000 0.5000 0.5001 ΣCT 4.8028 4.6691 4.8459 4.8455 ΣAT 2.9777 3.0245 2.9814 2.9693

[0163] According to the above-described embodiments, the optical imaging system can obtain high-quality and bright images and can be manufactured to have a small size, so that the optical imaging system can be used in mobile devices with limited space.

[0164] Although the present disclosure includes specific examples, it will be apparent after understanding the disclosure of the present application that various changes in form and detail may be made to these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be understood in a descriptive sense only and not for purposes of limitation. The description of features or aspects in each example should be considered 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 the components in the described systems, architectures, devices, or circuits are combined in different ways and / or replaced or supplemented by other components or their equivalents.

[0165] Therefore, the scope of the present disclosure includes the claims and their equivalents in addition to the above disclosure and all accompanying drawings, that is, all variations within the scope of the claims and their equivalents should be construed as being included in the present disclosure.

Claims

1. An optical imaging system, comprising: a first lens, a second lens, a third lens, a fourth lens having a positive refractive power, a fifth lens, a sixth lens, a seventh lens having a positive refractive power, an eighth lens, and a ninth lens, wherein, the first lens to the ninth lens are arranged in sequence from the object side, wherein, the condition expression 1.0 < F - number < 1.4 and 1.30 ≤ TTL / f < 1.40 is satisfied, wherein, TTL is the distance on the optical axis from the object surface of the first lens to the image plane, and f is the focal length of the optical imaging system, and wherein, the optical imaging system has a total of nine lenses.

2. The optical imaging system according to claim 1, wherein: The image surface of the third lens and the object surface of the fourth lens are both concave.

3. The optical imaging system according to claim 1, wherein: The fifth lens has a concave object surface.

4. The optical imaging system according to claim 1, wherein: The sixth lens has a concave image surface.

5. The optical imaging system according to claim 1, wherein: The seventh lens and the eighth lens include anastigmatic points on at least one of the object surface and the image surface.

6. The optical imaging system according to claim 1, wherein: The eighth lens has a convex image surface.

7. The optical imaging system according to claim 1, wherein: The first lens to the ninth lens include three or more lenses having a refractive index equal to or greater than 1.

60.

8. The optical imaging system according to claim 1, wherein: The condition expression 0.70 ≤ TTL / (2×IMGHT) < 0.80 is satisfied, wherein, IMG HT is half of the diagonal length of the image plane.

9. 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, an eighth lens, and a ninth lens arranged in sequence from the object side, wherein, the seventh lens has a positive refractive power, wherein, the eighth lens has a convex image surface, and [[ID= 10. The optical imaging system according to claim 9, wherein: ​ 11. The optical imaging system according to claim 9, wherein: ​ 12. The optical imaging system according to claim 9, wherein: ​ 13. The optical imaging system according to claim 9, wherein: ​ 14. The optical imaging system according to claim 9, wherein: ​ 15. The optical imaging system according to claim 9, wherein: ​ 16. The optical imaging system according to claim 9, wherein: ​ 17. The optical imaging system according to claim 9, wherein: ​ ​ 18. The optical imaging system according to claim 9, wherein: ​ ​

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