Optical image capturing system

Abstract

An optical imaging system includes: a first lens having positive refractive power; a second lens having negative refractive power; a third lens having a concave image side surface; a fourth lens having a concave image side surface; a fifth lens having refractive power; a sixth lens having refractive power; a seventh lens having refractive power; and an eighth lens having a negative refractive power, in which the optical imaging system includes a total of eight lenses having refractive power, in which the first to eighth lenses are sequentially disposed in a digital order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging plane of the optical imaging system, and in which the optical imaging system satisfies 0.8 lt; r16 / R1lt; r1 is the radius of curvature of the object-side surface of the first lens, and R16 is the radius of curvature of the image-side surface of the eighth lens.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of priority to Korean Patent Application Nos. 10 - 2018 - 0073614, filed with the Korean Intellectual Property Office on June 26, 2018, and 10 - 2019 - 0011429, filed with the Korean Intellectual Property Office on January 29, 2019. The entire disclosures of the above - mentioned Korean patent applications are incorporated herein by reference for all purposes. Technical field

[0003] This application relates to an optical imaging system including eight lenses. Background art

[0004] Mobile terminals are generally provided with cameras for video communication or taking images. However, due to space limitations inside the mobile terminal, it is difficult to achieve high performance in cameras for mobile terminals.

[0005] Therefore, as the number of mobile terminals equipped with cameras increases, the demand for an optical imaging system that can improve camera performance without increasing the size of the camera has increased. Summary of the invention

[0006] The Summary of the Invention section is intended to introduce, in a brief form, selections of inventive concepts, which 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 assist in determining the scope of the claimed subject matter.

[0007] In one general aspect, an optical imaging system includes: a first lens having a positive refractive power; a second lens having a refractive power; a third lens having a refractive power; a fourth lens having a refractive power and a concave image - side surface; a fifth lens having a refractive power; a sixth lens having a refractive power; a seventh lens having a refractive power; and an eighth lens having a refractive power and a concave object - side surface, wherein the first lens to the eighth lens are sequentially arranged in numerical order along the optical axis of the optical imaging system from the object side of the optical imaging system toward the imaging surface of the optical imaging system.

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

[0009] The object - side surface of the third lens may be convex.

[0010] The object - side surface of the fifth lens may be concave.

[0011] The image - side surface of the sixth lens may be convex.

[0012] The object - side surface of the seventh lens may be concave.

[0013] The optical imaging system can satisfy 0.1 < L1w / L8w < 0.3, where L1w is the weight of the first lens, L8w is the weight of the eighth lens, and L1w and L8w are expressed in the same measurement unit.

[0014] The optical imaging system may further include a spacer disposed between the seventh lens and the eighth lens, and the optical imaging system can satisfy 1.0 < S7d / f < 1.4, where S7d is the inner diameter of the spacer, f is the total focal length of the optical imaging system, and S7d and f are expressed in the same measurement unit.

[0015] The optical imaging system can satisfy 0.4 < L1TD / L8TD < 0.8, where L1TD is the total outer diameter of the first lens, L8TD is the total outer diameter of the eighth lens, and L1TD and L8TD are expressed in the same measurement unit.

[0016] The optical imaging system can satisfy 0.4 < L1234TDavg / L8TD < 0.8, where L1234TDavg is the average of the total outer diameters of the first lens to the fourth lens, L8TD is the total outer diameter of the eighth lens, and L1234TDavg and L8TD are expressed in the same measurement unit.

[0017] The optical imaging system can satisfy 0.5 < L12345TDavg / L8TD < 0.8, where L12345TDavg is the average of the total outer diameters of the first lens to the fifth lens, L8TD is the total outer diameter of the eighth lens, and L12345TDavg and L8TD are expressed in the same measurement unit.

[0018] The optical imaging system can satisfy (V2 + V4) / 2 < 20, where V2 is the Abbe number of the second lens and V4 is the Abbe number of the fourth lens.

[0019] The optical imaging system can satisfy 50 < (V5 + V6 + V7 + V8) / 4, where V5 is the Abbe number of the fifth lens, V6 is the Abbe number of the sixth lens, V7 is the Abbe number of the seventh lens, and V8 is the Abbe number of the eighth lens.

[0020] The optical imaging system can satisfy 1.6 < Nd2 < 1.8, where Nd2 is the refractive index of the second lens.

[0021] The optical imaging system can satisfy 1.6 < Nd4 < 1.8, where Nd4 is the refractive index of the fourth lens.

[0022] In another general aspect, an optical imaging system includes: a first lens having a refractive power; a second lens having a refractive power; a third lens having a refractive power; a fourth lens having a refractive power; a fifth lens having a positive refractive power and a convex image side; a sixth lens having a positive refractive power and a convex image side; a seventh lens having a refractive power; and an eighth lens having a negative refractive power, wherein the first lens to the eighth lens are sequentially arranged in numerical order along the optical axis of the optical imaging system from the object side of the optical imaging system toward the imaging surface of the optical imaging system.

[0023] Each of the first lens and the third lens may have a positive refractive power, and the second lens may have a negative refractive power.

[0024] Each of the first lens to the fourth lens may have a convex object side and a concave image side.

[0025] Each of the fifth lens, the seventh lens, and the eighth lens may have a concave object side, the seventh lens may have a convex image side, and the eighth lens may have a concave image side.

[0026] The optical imaging system may satisfy 1.0 < TTL / f1 < 1.4, where TTL is the distance along the optical axis from the object side of the first lens to the imaging surface, f1 is the focal length of the first lens, and TTL and f1 are expressed in the same measurement unit.

[0027] Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. Description of the Drawings

[0028] Figure 1 is a view showing a first example of the optical imaging system.

[0029] Figure 2 shows Figure 1 the aberration curve of the optical imaging system.

[0030] Figure 3 is a view showing a second example of the optical imaging system.

[0031] Figure 4 shows Figure 3 the aberration curve of the optical imaging system.

[0032] Figure 5 is a view showing a third example of the optical imaging system.

[0033] Figure 6 shows Figure 5 the aberration curve of the optical imaging system.

[0034] Figure 7 is a view showing a fourth example of the optical imaging system.

[0035] Figure 8 shows the Figure 7 aberration curve of the optical imaging system.

[0036] Figure 9 is a view showing a fifth example of an optical imaging system.

[0037] Figure 10 shows the Figure 9 aberration curve of the optical imaging system.

[0038] Figure 11 is a view showing a sixth example of an optical imaging system.

[0039] Figure 12 shows the Figure 11 aberration curve of the optical imaging system.

[0040] Figure 13 is a view showing a seventh example of an optical imaging system.

[0041] Figure 14 shows the Figure 13 aberration curve of the optical imaging system.

[0042] Figure 15 is a view showing an eighth example of an optical imaging system.

[0043] Figure 16 shows the Figure 15 aberration curve of the optical imaging system.

[0044] Figure 17 is a view showing a ninth example of an optical imaging system.

[0045] Figure 18 shows the Figure 17 aberration curve of the optical imaging system.

[0046] Figure 19 is a view showing a tenth example of an optical imaging system.

[0047] Figure 20 shows the Figure 19 aberration curve of the optical imaging system.

[0048] Figure 21 and Figure 22 is a cross-sectional view of an optical imaging system coupled to a lens barrel.

[0049] Figure 23 is a cross-sectional view showing an example of an eighth lens.

[0050] Figure 24 is a cross-sectional view showing an example of the shape of ribs of a lens.

[0051] In all of the figures and the detailed description, like reference numerals refer to like elements. For clarity, illustration, and convenience, the figures may not be drawn to scale, and the relative dimensions, proportions, and depiction of elements in the figures may be exaggerated. Detailed Description

[0052] The following detailed description is provided to assist the reader in obtaining a comprehensive understanding of the methods, devices, and / or systems described in this application. However, after understanding the disclosure of this application, various changes, modifications, and equivalents of the methods, devices, and / or systems described in this application will be apparent. For example, the order of operations described in this application is merely illustrative and, except for operations that must occur in a specific order, is not limited to the order set forth in this application but may be changed in an obvious manner after understanding the disclosure of this application. Additionally, descriptions of features known in the art may be omitted for greater clarity and conciseness.

[0053] The features described in this application may be implemented in different forms and should not be construed as limited to the examples described in this application. Rather, the examples described in this application are provided merely to illustrate some of the many possible ways of implementing the methods, devices, and / or systems described in this application, which will be apparent after understanding the disclosure of this application.

[0054] Throughout the specification, when an element such as a layer, region, or substrate is described as being "on," "connected to," or "coupled to" another element, the element may be directly "on," directly "connected to," or directly "coupled to" the other element, or there may be one or more other elements intervening between the element and the other element. In contrast, when an element is described as being "directly on," "directly connected to," or "directly coupled to" another element, there are no other elements intervening between the element and the other element.

[0055] As used in this application, the phrase "and / or" includes any one of the associated listed items and any combination of any two or more of them.

[0056] Although terms such as "first", "second", and "third" may be used in this application to describe various components, parts, regions, layers, or sections, these components, parts, regions, layers, or sections are not limited by these terms. Rather, these terms are only used to distinguish one component, part, region, layer, or section from another. Thus, without departing from the teachings of the examples described in this application, the first component, first part, first region, first layer, or first section mentioned in these examples may also be referred to as the second component, second part, second region, second layer, or second section.

[0057] Spatial relative terms such as "above", "upper", "below", and "lower" may be used in this application for convenience of description to describe the relationship of one element relative to another as shown in the figures. In addition to covering the orientations depicted in the figures, these spatial relative terms are intended to also cover different orientations of the device during use or operation. For example, if the device in the figures is flipped, an element described as "above" or "upper" relative to another element will be "below" or "lower" relative to that other element. Thus, depending on the spatial orientation of the device, the term "above" covers both the orientations of "above" and "below". The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relative terms used in this application should be interpreted accordingly.

[0058] The terms used in this application are only for describing various examples and are not intended to limit the disclosure. Unless the context clearly indicates otherwise, the articles "a", "an", and "the" are intended to include the plural forms as well. The terms "comprising", "including", and "having" specify the presence of the stated features, numbers, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, components, elements, and / or combinations thereof.

[0059] For ease of explanation, the thickness, size, and shape of the lens shown in the figures may be slightly exaggerated. Additionally, the shape of the spherical surface or aspherical surface of the lens described in the detailed description and shown in the detailed description or the figures is merely an example. That is, the shape of the spherical surface or aspherical surface of the lens is not limited to the examples described in this application.

[0060] The numerical values of the radius of curvature, thickness, distance between elements including the lens or surface, effective semi-aperture of the lens, focal length, and diameters, thicknesses, and lengths of various elements are expressed in millimeters (mm), while the angles are expressed in degrees. The thickness of the lens and the distance between elements including the lens or surface are measured along the optical axis of the optical imaging system.

[0061] The term "effective semi-aperture" used in this application refers to the radius of the portion of the surface of a lens or other element (the object side or the image side of the lens or other element) through which light actually passes. The effective semi-aperture is equal to the distance, measured perpendicular to the optical axis of the surface, between the optical axis of the surface and the outermost point on the surface through which light actually passes. Thus, the effective semi-aperture can be equal to the radius of the optical portion of the surface, or if light does not pass through the edge portion of the optical portion of the surface, the effective semi-aperture can be less than the radius of the optical portion of the surface. The object side and the image side of a lens or other element can have different effective semi-apertures.

[0062] In this application, unless otherwise specified, a reference to the shape of a lens surface refers to the shape of the paraxial region of the lens surface. The paraxial region of a lens surface is the central portion of the lens surface surrounding the optical axis of the lens surface, where the light rays incident on the lens surface make a small angle θ with the optical axis, and the following approximations are valid: sinθ≈θ, tanθ≈θ, and cosθ≈1.

[0063] For example, the statement that the object side of a lens is convex means that at least the paraxial region of the object side of the lens is convex, and the statement that the image side of a lens is concave means that at least the paraxial region of the image side of the lens is concave. Thus, even if the object side of a lens can be described as convex, the entire object side of the lens may not be convex, and the edge region of the object side of the lens can be concave. At the same time, even if the image side of a lens can be described as concave, the entire image side of the lens may not be concave, and the edge region of the image side of the lens can be convex.

[0064] Next, the configuration of the optical imaging system will be described.

[0065] The optical imaging system includes a plurality of lenses. For example, 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 numerical order along the optical axis of the optical imaging system from the object side of the optical imaging system toward the imaging surface of the optical imaging system. The first lens is the lens closest to the object (or subject) to be imaged by the optical imaging system, and the eighth lens is the lens closest to the imaging surface.

[0066] Each lens of the optical imaging system includes an optical portion and a rib. The optical portion of the lens is the portion of the lens configured to refract light and is typically formed in the central portion of the lens. The rib of the lens is the edge portion of the lens that enables the lens to be mounted in the lens barrel and aligns the optical axis of the lens with the optical axis of the optical imaging system. The rib of the lens extends radially outward from the optical portion. The optical portions of the lenses generally do not contact each other. For example, the first lens to the eighth lens are mounted in the lens barrel such that they are spaced apart from each other by a predetermined distance along the optical axis of the optical imaging system. The ribs of the lenses can selectively contact each other. For example, the ribs of the first lens to the fourth lens, or the ribs of the first lens to the fifth lens, or the ribs of the second lens to the fourth lens can contact each other such that the optical axes of these lenses can be easily aligned with the optical axis of the optical imaging system.

[0067] The optical imaging system further includes an image sensor and a filter. The image sensor forms an imaging surface and converts the light refracted by the first lens to the eighth lens into an electrical signal. The filter is disposed between the lens and the imaging surface and blocks infrared rays contained in the light refracted by the first lens to the eighth lens from incident on the imaging surface.

[0068] The optical imaging system further includes a diaphragm and a spacer. The diaphragm is disposed in front of the first lens, or between two adjacent lenses among the first lens to the eighth lens, or between the object side and the image side of one of the first lens to the eighth lens to adjust the amount of light incident on the imaging surface. Each of the spacers is disposed at a corresponding position between two of the first lens to the eighth lens to maintain a predetermined distance between the two lenses. Additionally, the spacer can be made of a light-shielding material to block external light from penetrating into the rib of the lens. There can be seven or eight spacers. For example, the first spacer is disposed between the first lens and the second lens, the second spacer is disposed between the second lens and the third lens, the third spacer is disposed between the third lens and the fourth lens, the fourth spacer is disposed between the fourth lens and the fifth lens, the fifth spacer is disposed between the fifth lens and the sixth lens, the sixth spacer is disposed between the sixth lens and the seventh lens, and the seventh spacer is disposed between the seventh lens and the eighth lens. Additionally, the optical imaging system can further include an eighth spacer disposed between the seventh lens and the seventh spacer.

[0069] Next, the lenses of the optical imaging system will be described.

[0070] The first lens has a refractive power. For example, the first lens can have a positive refractive power. One surface of the first lens can be convex. For example, the object side surface of the first lens can be convex. One surface of the first lens can be concave. For example, the image side surface of the first lens can be concave. The first lens can have an aspherical surface. For example, one surface or both surfaces of the first lens can be aspherical.

[0071] The second lens has a refractive power. For example, the second lens may have a negative refractive power. One surface of the second lens may be convex. For example, the object side surface of the second lens may be convex. One surface of the second lens may be concave. For example, the image side surface of the second lens may be concave. The second lens may include an aspherical surface. For example, one or both surfaces of the second lens may be aspherical.

[0072] The third lens has a refractive power. For example, the third lens may have a positive refractive power. One surface of the third lens may be convex. For example, the object side surface of the third lens may be convex. One surface of the third lens may be concave. For example, the image side surface of the third lens may be concave. The third lens may have an aspherical surface. For example, one or both surfaces of the third lens may be aspherical.

[0073] The fourth lens has a refractive power. For example, the fourth lens may have a positive refractive power or a negative refractive power. One surface of the fourth lens may be convex. For example, the object side surface of the fourth lens may be convex. One surface of the fourth lens may be concave. For example, the image side surface of the fourth lens may be concave. The fourth lens may have at least one inflection point. An inflection point is a point where the lens surface changes from convex to concave or from concave to convex. The number of inflection points is counted from the center of the lens to the outer edge of the optical portion of the lens. For example, at least one inflection point may be formed on either or both of the object side surface and the image side surface of the fourth lens. Therefore, at least one surface of the fourth lens may have a paraxial region and an edge region with different shapes from each other. For example, the paraxial region of the object side surface of the fourth lens may be convex, but the edge region of the object side surface of the fourth lens may be concave. The fourth lens may have an aspherical surface. For example, one or both surfaces of the fourth lens may be aspherical.

[0074] The fifth lens has a refractive power. For example, the fifth lens may have a positive refractive power. One surface of the fifth lens may be concave. For example, the object side surface of the fifth lens may be concave. One surface of the fifth lens may be convex. For example, the image side surface of the fifth lens may be convex. The fifth lens may have an aspherical surface. For example, one or both surfaces of the fifth lens may be aspherical.

[0075] The sixth lens has a refractive power. For example, the sixth lens may have a positive refractive power. One or both surfaces of the sixth lens may be convex. For example, the image side surface of the sixth lens may be convex, or both the object side surface and the image side surface of the sixth lens may be convex. One surface of the sixth lens may be concave. For example, the object side surface of the sixth lens may be concave. The sixth lens may have at least one inflection point. For example, at least one inflection point may be formed on either one or both of the object side surface and the image side surface of the sixth lens. Therefore, at least one surface of the sixth lens may have a paraxial region and a marginal region with different shapes from each other. For example, the paraxial region of the object side surface of the sixth lens may be concave, but the marginal region of the object side surface of the sixth lens may be convex. The sixth lens may have an aspherical surface. For example, one or both surfaces of the sixth lens may be aspherical.

[0076] The seventh lens has a refractive power. For example, the seventh lens may have a positive refractive power or a negative refractive power. One surface of the seventh lens may be concave. For example, the object side surface of the seventh lens may be concave. One surface of the seventh lens may be convex. For example, the image side surface of the seventh lens may be convex. The seventh lens may have at least one inflection point. For example, at least one inflection point may be formed on either one or both of the object side surface and the image side surface of the seventh lens. Therefore, at least one surface of the seventh lens may have a paraxial region and a marginal region with different shapes from each other. For example, the paraxial region of the object side surface of the seventh lens may be concave, but the marginal region of the object side surface of the seventh lens may be convex. The seventh lens may have an aspherical surface. For example, one or both surfaces of the seventh lens may be aspherical.

[0077] The eighth lens has a refractive power. For example, the eighth lens may have a negative refractive power. Both surfaces of the eighth lens may be concave. For example, the object side surface and the image side surface of the eighth lens may be concave. The eighth lens may have at least one inflection point. For example, at least one inflection point may be formed on either one or both of the object side surface and the image side surface of the eighth lens. Therefore, at least one surface of the eighth lens may have a paraxial region and a marginal region with different shapes from each other. For example, the paraxial region of the object side surface of the eighth lens may be concave, but the marginal region of the object side surface of the eighth lens may be convex. The eighth lens may have an aspherical surface. For example, one or both surfaces of the eighth lens may be aspherical.

[0078] The lenses of the optical imaging system may be made of an optical material with a high light transmittance. For example, the first lens to the eighth lens may be made of a plastic material. However, the materials of the first lens to the eighth lens are not limited to plastic materials.

[0079] The aspherical surfaces of the first lens to the eighth lens may be represented by Equation 1 below:

[0080]

[0081] In Equation 1, c is the curvature of the lens surface and is equal to the reciprocal of the radius of curvature of the lens surface at the optical axis of the lens surface. K is the conic constant, Y is the distance from a point on the aspherical surface of the lens in a direction perpendicular to the optical axis to the optical axis of the lens, A to H are aspherical constants, and Z (or sag) is the distance between a point on the aspherical surface of the lens at a distance Y from the optical axis and a tangent plane perpendicular to the optical axis that intersects the vertex of the aspherical surface of the lens. The examples disclosed in this application also include the aspherical constant J. The additional term JY 20 can be added to the right side of Equation 1 to reflect the influence of the aspherical constant J.

[0082] The optical imaging system can satisfy one or more of the following conditional expressions 1 to 24.

[0083] 0.1 < L1w / L8w < 0.3 (Conditional Expression 1)

[0084] 1.0 < S7d / f < 1.4 (Conditional Expression 2)

[0085] 0.4 < L1TD / L8TD < 0.8 (Conditional Expression 3)

[0086] 0.4 < L1234TDavg / L8TD < 0.8 (Conditional Expression 4)

[0087] 0.5 < L12345TDavg / L8TD < 0.8 (Conditional Expression 5)

[0088] (V2 + V4) / 2 < 20 (Conditional Expression 6)

[0089] 50 < (V5 + V6 + V7 + V8) / 4 (Conditional Expression 7)

[0090] 1.6 < Nd2 < 1.8 (Conditional Expression 8)

[0091] 1.6 < Nd4 < 1.8 (Conditional Expression 9)

[0092] Nd6 < 1.6 (Conditional Expression 10)

[0093] 0.8 < f1 / f5 < 1.4 (Conditional Expression 11)

[0094] -4.0 < f3 / f2 < -2.0 (Conditional Expression 12)

[0095] -2.0 < f5 / f8 < -1.0 (Conditional Expression 13)

[0096] 0.7 < f5 / f < 1.2 (Conditional Expression 14)

[0097] 1.0 < TTL / f1 < 1.4 (Condition Expression 15)

[0098] 1.0 < TTL / f5 < 1.8 (Condition Expression 16)

[0099] 0.9 < R7 / R8 < 1.2 (Condition Expression 17)

[0100] 0.8 < R13 / R14 < 1.2 (Condition Expression 18)

[0101] 0.8 < R16 / R1 < 1.2 (Condition Expression 19)

[0102] 3.4 < (R2 - R15) / (R1 + R16) < 5.0 (Condition Expression 20)

[0103] LT4 < LT3 or LT4 < LT5 (Condition Expression 21)

[0104] 2.0 < |R15 / R16| < 5.0 (Condition Expression 22)

[0105] 3.0 < (R7 * R9) / (R8 * R10) < 5.0 (Condition Expression 23)

[0106] 0.2 < (R7 * R10) / (R8 * R9) < 0.4 (Condition Expression 24)

[0107] In the above condition expressions, L1w is the weight of the first lens expressed in mg, and L8w is the weight of the eighth lens expressed in mg.

[0108] S7d is the inner diameter of the seventh spacer expressed in mm, and f is the total focal length of the optical imaging system expressed in mm.

[0109] L1TD is the total outer diameter of the first lens expressed in mm, and L8TD is the total outer diameter of the eighth lens expressed in mm. The total outer diameter of a lens is the diameter of the lens (including the optical part of the lens and the ribs of the lens).

[0110] L1234TDavg is the average value of the total outer diameters of the first lens to the fourth lens expressed in mm, and L12345TDavg is the average value of the total outer diameters of the first lens to the fifth lens expressed in mm.

[0111] V2 is the Abbe number of the second lens, V4 is the Abbe number of the fourth lens, V5 is the Abbe number of the fifth lens, V6 is the Abbe number of the sixth lens, V7 is the Abbe number of the seventh lens, and V8 is the Abbe number of the eighth lens.

[0112] Nd2 is the refractive index of the second lens, Nd4 is the refractive index of the fourth lens, and Nd6 is the refractive index of the sixth lens.

[0113] f1 is the focal length of the first lens in mm, f2 is the focal length of the second lens in mm, f3 is the focal length of the third lens in mm, f5 is the focal length of the fifth lens in mm, f8 is the focal length of the eighth lens in mm, and TTL is the distance along the optical axis of the optical imaging system from the object side of the first lens to the imaging surface of the optical imaging system in mm;

[0114] R1 is the radius of curvature of the object side of the first lens in mm, R2 is the radius of curvature of the image side of the first lens in mm, R7 is the radius of curvature of the object side of the fourth lens in mm, R8 is the radius of curvature of the image side of the fourth lens in mm, R9 is the radius of curvature of the object side of the fifth lens in mm, R10 is the radius of curvature of the image side of the fifth lens in mm, R13 is the radius of curvature of the object side of the seventh lens in mm, R14 is the radius of curvature of the image side of the seventh lens in mm, R15 is the radius of curvature of the object side of the eighth lens in mm, and R16 is the radius of curvature of the image side of the eighth lens in mm.

[0115] LT3 is the thickness along the optical axis of the third lens in mm, LT4 is the thickness along the optical axis of the fourth lens in mm, and LT5 is the thickness along the optical axis of the fifth lens in mm.

[0116] Condition expressions 1 and 3 specify the ranges of the weight ratio and the total outer diameter ratio between the first lens and the eighth lens to facilitate the self-alignment between the lenses and the alignment between the lenses and the lens barrel.

[0117] Condition expression 2 specifies the range of the ratio of the inner diameter of the seventh spacer to the total focal length of the optical imaging system to minimize the flash phenomenon.

[0118] Condition expressions 4 and 5 specify the total outer diameter ratio between the lenses to facilitate aberration correction.

[0119] The optical imaging system can satisfy condition expression 10 while satisfying condition expression 8 or 9.

[0120] Next, a plurality of examples of the optical imaging system will be described. In the table described below, S1 represents the object side surface of the first lens, S2 represents the image side surface of the first lens, S3 represents the object side surface of the second lens, S4 represents the image side surface of the second lens, S5 represents the object side surface of the third lens, S6 represents the image side surface of the third lens, S7 represents the object side surface of the fourth lens, S8 represents the image side surface of the fourth lens, S9 represents the object side surface of the fifth lens, S10 represents the image side surface of the fifth lens, S11 represents the object side surface of the sixth lens, S12 represents the image side surface of the sixth lens, S13 represents the object side surface of the seventh lens, S14 represents the image side surface of the seventh lens, S15 represents the object side surface of the eighth lens, S16 represents the image side surface of the eighth lens, S17 represents the object side surface of the filter, S18 represents the image side surface of the filter, and S19 represents the imaging surface.

[0121] Example 1

[0122] Figure 1 is a view showing a first example of the optical imaging system, and Figure 2 shows Figure 1 the aberration curve of the optical imaging system.

[0123] The optical imaging system 101 includes a first lens 1001, a second lens 2001, a third lens 3001, a fourth lens 4001, a fifth lens 5001, a sixth lens 6001, a seventh lens 7001, and an eighth lens 8001.

[0124] The first lens 1001 has a positive refractive power, a convex object side surface, and a concave image side surface. The second lens 2001 has a negative refractive power, a convex object side surface, and a concave image side surface. The third lens 3001 has a positive refractive power, a convex object side surface, and a concave image side surface. The fourth lens 4001 has a positive refractive power, a convex object side surface, and a concave image side surface. Additionally, at least one inflection point is formed on either or both of the object side surface and the image side surface of the fourth lens 4001. The fifth lens 5001 has a positive refractive power, a concave object side surface, and a convex image side surface. The sixth lens 6001 has a positive refractive power, a concave object side surface, and a convex image side surface. Additionally, at least one inflection point is formed on either or both of the object side surface and the image side surface of the sixth lens 6001. The seventh lens 7001 has a negative refractive power, a concave object side surface, and a convex image side surface. Additionally, at least one inflection point is formed on either or both of the object side surface and the image side surface of the seventh lens 7001. The eighth lens 8001 has a negative refractive power, a concave object side surface, and a concave image side surface. Additionally, at least one inflection point is formed on either or both of the object side surface and the image side surface of the eighth lens 8001.

[0125] The optical imaging system 101 further includes a diaphragm, a filter 9001, and an image sensor 9101. The diaphragm is disposed between the first lens 1001 and the second lens 2001 to adjust the amount of light incident on the image sensor 9101. The filter 9001 is disposed between the eighth lens 8001 and the image sensor 9101 to block infrared rays. The image sensor 9101 forms an imaging surface on which an image of an object is formed. Although Figure 1 not shown in Figure 1 , the diaphragm is disposed at a distance of 0.860 mm from the object side surface of the first lens 1001 toward the imaging surface of the optical imaging system 101. This distance is equal to TTL-SL and can be calculated from the values of TTL and SL in Example 1 listed in Table 21 presented later in this application.

[0126] Table 1 below shows Figure 1 the physical characteristics of the lenses and other elements of the optical imaging system, and Table 2 below shows Figure 1 the aspherical surface coefficients of the lenses of Figure 1 . Figure 1 Both surfaces of all the lenses of Figure 1 are aspherical.

[0127] Table 1

[0128]

[0129]

[0130] Table 2

[0131] K A B C D E F G H J S1 -1.0480 0.0221 0.0111 -0.0338 0.0934 -0.1598 0.1654 -0.1021 0.0340 -0.0048 S2 -0.8852 -0.0418 0.0586 -0.2214 0.5998 -1.0430 1.1258 -0.7342 0.2649 -0.0406 S3 -3.9564 -0.0963 0.1879 -0.5654 1.6233 -3.0298 3.5408 -2.5024 0.9796 -0.1630 S4 -4.8667 -0.0683 0.1256 -0.2315 0.5981 -1.1574 1.4929 -1.1835 0.5215 -0.0960 S5 -6.0535 -0.0537 0.0641 -0.3843 1.0760 -2.0031 2.3634 -1.6902 0.6673 -0.1104 S6 -1.0507 -0.1016 0.0933 -0.2230 0.3347 -0.4324 0.3856 -0.2085 0.0649 -0.0098 S7 4.6044 -0.2324 0.1982 -0.6013 1.3820 -2.0781 1.9419 -1.0915 0.3428 -0.0471 S8 -8.7421 -0.1572 0.0982 -0.2661 0.5435 -0.6878 0.5413 -0.2572 0.0673 -0.0074 S9 -27.3339 -0.0147 0.0237 -0.0936 0.1181 -0.0890 0.0466 -0.0175 0.0040 -0.0004 S10 -1.3994 0.1191 -0.1718 0.1368 -0.0764 0.0328 -0.0096 0.0017 -0.0002 0.0000 S11 -2.3975 0.0534 -0.1241 0.0939 -0.0632 0.0302 -0.0086 0.0014 -0.0001 0.0000 S12 -0.2466 -0.0316 0.0469 -0.0312 0.0109 -0.0022 0.0002 0.0000 0.0000 0.0000 S13 -13.5145 0.0262 -0.0386 0.0262 -0.0103 0.0024 -0.0003 0.0000 0.0000 0.0000 S14 -50.6951 0.1183 -0.1302 0.0693 -0.0200 0.0028 -0.0001 0.0000 0.0000 0.0000 S15 -98.5085 -0.0783 -0.0178 0.0631 -0.0361 0.0102 -0.0017 0.0002 0.0000 0.0000 S16 -1.1776 -0.2027 0.1040 -0.0371 0.0092 -0.0016 0.0002 0.0000 0.0000 0.0000

[0132] Example 2

[0133] Figure 3 is a view showing a second example of the optical imaging system, and Figure 4 shows Figure 3 the aberration curves of the optical imaging system of Figure 3 .

[0134] The optical imaging system 102 includes a first lens 1002, a second lens 2002, a third lens 3002, a fourth lens 4002, a fifth lens 5002, a sixth lens 6002, a seventh lens 7002, and an eighth lens 8002.

[0135] The first lens 1002 has a positive refractive power, a convex object side, and a concave image side. The second lens 2002 has a negative refractive power, a convex object side, and a concave image side. The third lens 3002 has a positive refractive power, a convex object side, and a concave image side. The fourth lens 4002 has a positive refractive power, a convex object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the fourth lens 4002. The fifth lens 5002 has a positive refractive power, a concave object side, and a convex image side. The sixth lens 6002 has a positive refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the sixth lens 6002. The seventh lens 7002 has a negative refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the seventh lens 7002. The eighth lens 8002 has a negative refractive power, a concave object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the eighth lens 8002.

[0136] The optical imaging system 102 further includes a diaphragm, a filter 9002, and an image sensor 9102. The diaphragm is disposed between the first lens 1002 and the second lens 2002 to adjust the amount of light incident on the image sensor 9102. The filter 9002 is disposed between the eighth lens 8002 and the image sensor 9102 to block infrared rays. The image sensor 9102 forms an imaging surface on which an image of the object is formed. Although Figure 3 not shown in the figure, the diaphragm is disposed at a distance of 0.844 mm from the object side of the first lens 1002 toward the imaging surface of the optical imaging system 102. This distance is equal to TTL-SL and can be calculated from the values of TTL and SL in Example 2 listed in Table 21 presented later in this application.

[0137] The following Table 3 shows Figure 3 the physical characteristics of the lenses and other elements of the optical imaging system of Figure 3 and the following Table 4 shows Figure 3 the aspherical surface coefficients of the lenses of

[0138] Table 3

[0139]

[0140] Table 4

[0141]

[0142]

[0143] Example 3

[0144] Figure 5 is a view showing a third example of an optical imaging system, and Figure 6 shows Figure 5 the aberration curve of the optical imaging system.

[0145] The optical imaging system 103 includes a first lens 1003, a second lens 2003, a third lens 3003, a fourth lens 4003, a fifth lens 5003, a sixth lens 6003, a seventh lens 7003, and an eighth lens 8003.

[0146] The first lens 1003 has a positive refractive power, a convex object side, and a concave image side. The second lens 2003 has a negative refractive power, a convex object side, and a concave image side. The third lens 3003 has a positive refractive power, a convex object side, and a concave image side. The fourth lens 4003 has a positive refractive power, a convex object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the fourth lens 4003. The fifth lens 5003 has a positive refractive power, a concave object side, and a convex image side. The sixth lens 6003 has a positive refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the sixth lens 6003. The seventh lens 7003 has a negative refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the seventh lens 7003. The eighth lens 8003 has a negative refractive power, a concave object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the eighth lens 8003.

[0147] The optical imaging system 103 further includes a diaphragm, a filter 9003, and an image sensor 9103. The diaphragm is disposed between the first lens 1003 and the second lens 2003 to adjust the amount of light incident on the image sensor 9103. The filter 9003 is disposed between the eighth lens 8003 and the image sensor 9103 to block infrared rays. The image sensor 9103 forms an imaging surface on which an image of an object is formed. Although Figure 5 not shown in, the diaphragm is disposed at a distance of 0.855 mm from the object side of the first lens 1003 toward the imaging surface of the optical imaging system 103. This distance is equal to TTL-SL and can be calculated from the values of TTL and SL of Example 3 listed in Table 21 presented later in this application.

[0148] The following Table 5 shows Figure 5the physical characteristics of the lenses and other components of the optical imaging system, and Table 6 below shows Figure 5 the aspherical surface coefficients of the lenses of Figure 5 Both surfaces of all the lenses of

[0149] Table 5

[0150]

[0151] Table 6

[0152]

[0153]

[0154] Example 4

[0155] Figure 7 is a view showing a fourth example of the optical imaging system, and Figure 8 shows Figure 7 the aberration curve of the optical imaging system of

[0156] The optical imaging system 104 includes a first lens 1004, a second lens 2004, a third lens 3004, a fourth lens 4004, a fifth lens 5004, a sixth lens 6004, a seventh lens 7004, and an eighth lens 8004.

[0157] The first lens 1004 has a positive refractive power, a convex object side, and a concave image side. The second lens 2004 has a negative refractive power, a convex object side, and a concave image side. The third lens 3004 has a positive refractive power, a convex object side, and a concave image side. The fourth lens 4004 has a negative refractive power, a convex object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the fourth lens 4004. The fifth lens 5004 has a positive refractive power, a concave object side, and a convex image side. The sixth lens 6004 has a positive refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the sixth lens 6004. The seventh lens 7004 has a positive refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the seventh lens 7004. The eighth lens 8004 has a negative refractive power, a concave object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the eighth lens 8004.

[0158] The optical imaging system 104 further includes a diaphragm, a filter 9004, and an image sensor 9104. The diaphragm is disposed between the first lens 1004 and the second lens 2004 to adjust the amount of light incident on the image sensor 9104. The filter 9004 is disposed between the eighth lens 8004 and the image sensor 9104 to block infrared rays. The image sensor 9104 forms an imaging surface on which an image of an object is formed. Although Figure 7 is not shown, the diaphragm is disposed at a distance of 0.872 mm from the object side surface of the first lens 1004 toward the imaging surface of the optical imaging system 104. This distance is equal to TTL-SL and can be calculated from the values of TTL and SL in Example 4 listed in Table 21 presented later in this application.

[0159] Table 7 below shows Figure 7 the physical characteristics of the lenses and other elements of the optical imaging system, and Table 8 below shows Figure 7 the aspherical surface coefficients of the lenses. Figure 7 Both surfaces of all the lenses of

[0160] Table 7

[0161]

[0162] Table 8

[0163]

[0164]

[0165] Example 5

[0166] Figure 9 is a view showing a fifth example of the optical imaging system, and Figure 10 shows Figure 9 the aberration curves of the optical imaging system.

[0167] The optical imaging system 105 includes a first lens 1005, a second lens 2005, a third lens 3005, a fourth lens 4005, a fifth lens 5005, a sixth lens 6005, a seventh lens 7005, and an eighth lens 8005.

[0168] The first lens 1005 has a positive refractive power, a convex object side, and a concave image side. The second lens 2005 has a negative refractive power, a convex object side, and a concave image side. The third lens 3005 has a positive refractive power, a convex object side, and a concave image side. The fourth lens 4005 has a positive refractive power, a convex object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the fourth lens 4005. The fifth lens 5005 has a positive refractive power, a concave object side, and a convex image side. The sixth lens 6005 has a positive refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the sixth lens 6005. The seventh lens 7005 has a positive refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the seventh lens 7005. The eighth lens 8005 has a negative refractive power, a concave object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the eighth lens 8005.

[0169] The optical imaging system 105 further includes a diaphragm, a filter 9005, and an image sensor 9105. The diaphragm is disposed between the first lens 1005 and the second lens 2005 to adjust the amount of light incident on the image sensor 9105. The filter 9005 is disposed between the eighth lens 8005 and the image sensor 9105 to block infrared rays. The image sensor 9105 forms an imaging surface on which an image of an object is formed. Although Figure 9 not shown in the figure, the diaphragm is disposed at a distance of 0.894 mm from the object side of the first lens 1005 toward the imaging surface of the optical imaging system 105. This distance is equal to TTL-SL and can be calculated from the values of TTL and SL in Example 5 listed in Table 21 presented later in this application.

[0170] The following Table 9 shows Figure 9 the physical characteristics of the lenses and other elements of the optical imaging system of Figure 9 and the following Table 10 shows Figure 9 the aspherical surface coefficients of the lenses of

[0171] Table 9

[0172]

[0173] Table 10

[0174]

[0175]

[0176] Example 6

[0177] Figure 11 is a view showing a sixth example of an optical imaging system, and Figure 12 shows Figure 11 the aberration curve of the optical imaging system.

[0178] The optical imaging system 106 includes a first lens 1006, a second lens 2006, a third lens 3006, a fourth lens 4006, a fifth lens 5006, a sixth lens 6006, a seventh lens 7006, and an eighth lens 8006.

[0179] The first lens 1006 has a positive refractive power, a convex object side, and a concave image side. The second lens 2006 has a negative refractive power, a convex object side, and a concave image side. The third lens 3006 has a positive refractive power, a convex object side, and a concave image side. The fourth lens 4006 has a negative refractive power, a convex object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the fourth lens 4006. The fifth lens 5006 has a positive refractive power, a concave object side, and a convex image side. The sixth lens 6006 has a positive refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the sixth lens 6006. The seventh lens 7006 has a positive refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the seventh lens 7006. The eighth lens 8006 has a negative refractive power, a concave object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the eighth lens 8006.

[0180] The optical imaging system 106 further includes a diaphragm, a filter 9006, and an image sensor 9106. The diaphragm is disposed between the first lens 1006 and the second lens 2006 to adjust the amount of light incident on the image sensor 9106. The filter 9006 is disposed between the eighth lens 8006 and the image sensor 9106 to block infrared rays. The image sensor 9106 forms an imaging surface on which an image of an object is formed. Although Figure 11 not shown in, the diaphragm is disposed at a distance of 0.916 mm from the object side of the first lens 1006 toward the imaging surface of the optical imaging system 106. This distance is equal to TTL - SL and can be calculated from the values of TTL and SL of Example 6 listed in Table 21 presented later in this application.

[0181] The following Table 11 shows Figure 11the physical properties of the lenses and other components of the optical imaging system, and Table 12 below shows Figure 11 the aspherical surface coefficients of the lenses of Figure 11 Both surfaces of all the lenses of

[0182] Table 11

[0183]

[0184] Table 12

[0185] K A B C D E F G H J S1 -1.0515 0.0418 -0.0820 0.1925 -0.2543 0.1923 -0.0752 0.0071 0.0040 -0.0010 S2 3.6745 -0.0613 0.2225 -0.7907 1.7333 -2.4105 2.1242 -1.1513 0.3501 -0.0457 S3 -4.7433 -0.1131 0.4407 -1.7856 4.8220 -8.1035 8.5172 -5.4431 1.9346 -0.2931 S4 -7.1170 -0.0380 -0.0420 0.4519 -1.4690 2.9676 -3.7762 2.9509 -1.2921 0.2441 S5 -10.0000 -0.0813 0.4039 -2.1741 6.2263 -11.0124 12.1279 -8.0775 2.9710 -0.4610 S6 -8.1202 -0.0930 0.2154 -0.8812 2.0731 -3.2144 3.1419 -1.8477 0.5981 -0.0824 S7 7.4360 -0.2802 0.6256 -2.2575 5.2300 -7.7298 7.1778 -4.0296 1.2473 -0.1635 S8 -18.0377 -0.1986 0.2619 -0.7200 1.3451 -1.6252 1.2637 -0.6035 0.1594 -0.0176 S9 -27.6060 -0.0669 0.2057 -0.4831 0.5917 -0.4462 0.2209 -0.0712 0.0135 -0.0011 S10 -1.2918 0.1394 -0.2240 0.1863 -0.1077 0.0497 -0.0161 0.0032 -0.0003 0.0000 S11 -3.6588 0.1104 -0.2597 0.2419 -0.1481 0.0577 -0.0137 0.0019 -0.0001 0.0000 S12 -0.6513 -0.0169 0.0325 -0.0266 0.0100 -0.0020 0.0002 0.0000 0.0000 0.0000 S13 -4.5082 0.0824 -0.1191 0.0703 -0.0231 0.0046 -0.0005 0.0000 0.0000 0.0000 S14 -37.6498 0.2062 -0.3215 0.2315 -0.0934 0.0226 -0.0034 0.0003 0.0000 0.0000 S15 -99.0000 -0.1155 -0.0315 0.1041 -0.0604 0.0174 -0.0029 0.0003 0.0000 0.0000 S16 -1.2552 -0.2449 0.1488 -0.0586 0.0151 -0.0026 0.0003 0.0000 0.0000 0.0000

[0186] Example 7

[0187] Figure 13 is a view showing a seventh example of an optical imaging system, and Figure 14 shows Figure 13 the aberration curve of the optical imaging system of

[0188] The optical imaging system 107 includes a first lens 1007, a second lens 2007, a third lens 3007, a fourth lens 4007, a fifth lens 5007, a sixth lens 6007, a seventh lens 7007, and an eighth lens 8007.

[0189] The first lens 1007 has a positive refractive power, a convex object side, and a concave image side. The second lens 2007 has a negative refractive power, a convex object side, and a concave image side. The third lens 3007 has a positive refractive power, a convex object side, and a concave image side. The fourth lens 4007 has a negative refractive power, a convex object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the fourth lens 4007. The fifth lens 5007 has a positive refractive power, a concave object side, and a convex image side. The sixth lens 6007 has a positive refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the sixth lens 6007. The seventh lens 7007 has a positive refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the seventh lens 7007. The eighth lens 8007 has a negative refractive power, a concave object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the eighth lens 8007.

[0190] The optical imaging system 107 further includes a diaphragm, a filter 9007, and an image sensor 9107. The diaphragm is disposed between the first lens 1007 and the second lens 2007 to adjust the amount of light incident on the image sensor 9107. The filter 9007 is disposed between the eighth lens 8007 and the image sensor 9107 to block infrared rays. The image sensor 9107 forms an imaging surface on which an image of an object is formed. Although Figure 13 is not shown, the diaphragm is disposed at a distance of 0.920 mm from the object side surface of the first lens 1007 toward the imaging surface of the optical imaging system 107. This distance is equal to TTL-SL and can be calculated from the values of TTL and SL in Example 7 listed in Table 21 presented later in this application.

[0191] Table 13 below shows Figure 13 the physical characteristics of the lenses and other elements of the optical imaging system, and Table 14 below shows Figure 13 the aspherical surface coefficients of the lenses of Figure 13 Both surfaces of all the lenses of

[0192] Table 13

[0193]

[0194]

[0195] Table 14

[0196] K A B C D E F G H J S1 -1.0633 0.0433 -0.1029 0.2763 -0.4432 0.4446 -0.2800 0.1065 -0.0224 0.0020 S2 5.7198 -0.0446 0.0892 -0.2735 0.5366 -0.6849 0.5629 -0.2886 0.0840 -0.0106 S3 -4.7433 -0.0954 0.3142 -1.2053 3.1368 -5.0428 5.0474 -3.0623 1.0313 -0.1479 S4 -6.8939 -0.0489 0.0707 0.0420 -0.6661 2.0606 -3.2101 2.7869 -1.2842 0.2464 S5 -9.5450 -0.0840 0.4445 -2.3444 6.5487 -11.2592 12.0270 -7.7610 2.7681 -0.4176 S6 -8.1202 -0.0609 -0.0304 0.1542 -0.5663 0.9636 -0.9982 0.6448 -0.2320 0.0344 S7 8.3930 -0.2820 0.6104 -2.0586 4.4420 -6.1262 5.3184 -2.7949 0.8116 -0.1003 S8 -16.9723 -0.2080 0.3147 -0.8767 1.6222 -1.9279 1.4724 -0.6933 0.1816 -0.0200 S9 -27.6060 -0.0707 0.2362 -0.5507 0.6652 -0.4825 0.2246 -0.0676 0.0120 -0.0010 S10 -1.2807 0.1478 -0.2466 0.2136 -0.1292 0.0622 -0.0209 0.0042 -0.0005 0.0000 S11 -3.6588 0.1163 -0.2758 0.2744 -0.1767 0.0706 -0.0171 0.0024 -0.0002 0.0000 S12 1.5936 -0.0208 0.0436 -0.0355 0.0134 -0.0028 0.0003 0.0000 0.0000 0.0000 S13 -4.2761 0.0942 -0.1361 0.0794 -0.0254 0.0049 -0.0006 0.0000 0.0000 0.0000 S14 -43.4471 0.2139 -0.3417 0.2495 -0.1017 0.0248 -0.0037 0.0003 0.0000 0.0000 S15 -99.0000 -0.1257 -0.0364 0.1176 -0.0688 0.0200 -0.0033 0.0003 0.0000 0.0000 S16 -1.3165 -0.2595 0.1617 -0.0644 0.0168 -0.0029 0.0003 0.0000 0.0000 0.0000

[0197] Example 8

[0198] Figure 15 is a view showing an eighth example of the optical imaging system, and Figure 16 shows Figure 15 the aberration curves of the optical imaging system of

[0199] The optical imaging system 108 includes a first lens 1008, a second lens 2008, a third lens 3008, a fourth lens 4008, a fifth lens 5008, a sixth lens 6008, a seventh lens 7008, and an eighth lens 8008.

[0200] The first lens 1008 has a positive refractive power, a convex object side and a concave image side. The second lens 2008 has a negative refractive power, a convex object side and a concave image side. The third lens 3008 has a positive refractive power, a convex object side and a concave image side. The fourth lens 4008 has a negative refractive power, a convex object side and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the fourth lens 4008. The fifth lens 5008 has a positive refractive power, a concave object side and a convex image side. The sixth lens 6008 has a positive refractive power, a convex object side and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the sixth lens 6008. The seventh lens 7008 has a negative refractive power, a concave object side and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the seventh lens 7008. The eighth lens 8008 has a negative refractive power, a concave object side and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the eighth lens 8008.

[0201] The optical imaging system 108 further includes a diaphragm, a filter 9008, and an image sensor 9108. The diaphragm is disposed between the first lens 1008 and the second lens 2008 to adjust the amount of light incident on the image sensor 9108. The filter 9008 is disposed between the eighth lens 8008 and the image sensor 9108 to block infrared rays. The image sensor 9108 forms an imaging surface on which an image of an object is formed. Although Figure 15 not shown in, the diaphragm is disposed at a distance of 1.126 mm from the object side of the first lens 1008 toward the imaging surface of the optical imaging system 108. This distance is equal to TTL-SL and can be calculated from the values of TTL and SL in Example 8 listed in Table 21 presented later in this application.

[0202] The following Table 15 shows Figure 15 the physical characteristics of the lenses and other elements of the optical imaging system of, and the following Table 16 shows Figure 15 the aspherical surface coefficients of the lenses of. Figure 15 Both surfaces of all the lenses of are aspherical.

[0203] Table 15

[0204]

[0205]

[0206] Table 16

[0207] K A B C D E F G H J S1 -1.0636 0.0197 -0.0275 0.0526 -0.0617 0.0469 -0.0230 0.0070 -0.0012 0.0001 S2 5.7362 -0.0344 0.0680 -0.1062 0.0950 -0.0483 0.0118 -0.0001 -0.0005 0.0001 S3 -4.7433 -0.0521 0.1005 -0.1930 0.2614 -0.2300 0.1313 -0.0469 0.0095 -0.0008 S4 -6.5299 -0.0138 -0.0311 0.1552 -0.3169 0.3807 -0.2792 0.1236 -0.0304 0.0032 S5 -9.9944 -0.0353 0.1039 -0.3590 0.6415 -0.7112 0.4900 -0.2036 0.0467 -0.0045 S6 -8.1202 -0.0303 -0.0065 0.0085 -0.0175 0.0083 -0.0006 -0.0002 -0.0001 0.0000 S7 8.1818 -0.1384 0.1951 -0.4447 0.6468 -0.5970 0.3448 -0.1202 0.0231 -0.0019 S8 -16.7481 -0.1042 0.1036 -0.1904 0.2300 -0.1763 0.0857 -0.0254 0.0042 -0.0003 S9 -27.6061 -0.0269 0.0604 -0.0932 0.0701 -0.0314 0.0092 -0.0018 0.0002 0.0000 S10 -1.2752 0.0694 -0.0641 0.0286 -0.0094 0.0031 -0.0008 0.0001 0.0000 0.0000 S11 -3.6588 0.0558 -0.0799 0.0493 -0.0202 0.0052 -0.0008 0.0001 0.0000 0.0000 S12 8.2769 -0.0069 0.0110 -0.0064 0.0016 -0.0002 0.0000 0.0000 0.0000 0.0000 S13 -4.6710 0.0496 -0.0469 0.0178 -0.0037 0.0004 0.0000 0.0000 0.0000 0.0000 S14 -46.5147 0.1094 -0.1080 0.0490 -0.0125 0.0019 -0.0002 0.0000 0.0000 0.0000 S15 -99.0000 -0.0704 -0.0077 0.0224 -0.0085 0.0016 -0.0002 0.0000 0.0000 0.0000 S16 -1.3258 -0.1343 0.0524 -0.0128 0.0020 -0.0002 0.0000 0.0000 0.0000 0.0000

[0208] Example 9

[0209] Figure 17 is a view showing a ninth example of an optical imaging system, and Figure 18 shows Figure 17 the aberration curves of the optical imaging system of

[0210] The optical imaging system 109 includes a first lens 1009, a second lens 2009, a third lens 3009, a fourth lens 4009, a fifth lens 5009, a sixth lens 6009, a seventh lens 7009, and an eighth lens 8009.

[0211] The first lens 1009 has a positive refractive power, a convex object side, and a concave image side. The second lens 2009 has a negative refractive power, a convex object side, and a concave image side. The third lens 3009 has a positive refractive power, a convex object side, and a concave image side. The fourth lens 4009 has a negative refractive power, a convex object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the fourth lens 4009. The fifth lens 5009 has a positive refractive power, a concave object side, and a convex image side. The sixth lens 6009 has a positive refractive power, a convex object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the sixth lens 6009. The seventh lens 7009 has a negative refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the seventh lens 7009. The eighth lens 8009 has a negative refractive power, a concave object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the eighth lens 8009.

[0212] The optical imaging system 109 further includes a diaphragm, a filter 9009, and an image sensor 9109. The diaphragm is disposed between the first lens 1009 and the second lens 2009 to adjust the amount of light incident on the image sensor 9109. The filter 9009 is disposed between the eighth lens 8009 and the image sensor 9109 to block infrared rays. The image sensor 9109 forms an imaging surface on which an image of an object is formed. Although Figure 17 not shown in , the diaphragm is disposed at a distance of 1.155 mm from the object side of the first lens 1009 toward the imaging surface of the optical imaging system 109. This distance is equal to TTL - SL and can be calculated from the values of TTL and SL of Example 9 listed in Table 21 presented later in this application.

[0213] The following Table 17 showsFigure 17 the physical properties of the lenses and other elements of the optical imaging system, and Table 18 below shows Figure 17 the aspherical surface coefficients of the lenses of Figure 17 Both surfaces of all the lenses of

[0214] Table 17

[0215]

[0216]

[0217] Table 18

[0218] K A B C D E F G H J S1 -1.0622 0.0178 -0.0128 0.0076 0.0100 -0.0198 0.0144 -0.0055 0.0011 -0.0001 S2 5.6036 -0.0363 0.0809 -0.1406 0.1463 -0.0947 0.0379 -0.0089 0.0011 -0.0001 S3 -4.7433 -0.0542 0.1147 -0.2402 0.3450 -0.3169 0.1866 -0.0680 0.0140 -0.0012 S4 -6.5766 -0.0084 -0.0570 0.2177 -0.4092 0.4647 -0.3247 0.1372 -0.0322 0.0032 S5 -9.7993 -0.0432 0.1425 -0.4371 0.7280 -0.7662 0.5092 -0.2065 0.0466 -0.0045 S6 -8.1202 -0.0370 0.0257 -0.0664 0.0888 -0.0872 0.0531 -0.0183 0.0033 -0.0002 S7 8.0131 -0.1310 0.1547 -0.3453 0.5063 -0.4744 0.2772 -0.0972 0.0187 -0.0015 S8 -16.4648 -0.1035 0.0974 -0.1744 0.2085 -0.1592 0.0775 -0.0231 0.0038 -0.0003 S9 -27.6060 -0.0275 0.0645 -0.1014 0.0782 -0.0359 0.0106 -0.0021 0.0002 0.0000 S10 -1.2775 0.0710 -0.0663 0.0301 -0.0099 0.0032 -0.0008 0.0001 0.0000 0.0000 S11 -3.6588 0.0555 -0.0795 0.0492 -0.0202 0.0052 -0.0008 0.0001 0.0000 0.0000 S12 7.8127 -0.0068 0.0108 -0.0063 0.0016 -0.0002 0.0000 0.0000 0.0000 0.0000 S13 -4.2234 0.0503 -0.0474 0.0180 -0.0037 0.0005 0.0000 0.0000 0.0000 0.0000 S14 -47.1881 0.1086 -0.1068 0.0483 -0.0123 0.0019 -0.0002 0.0000 0.0000 0.0000 S15 -99.0000 -0.0713 -0.0073 0.0223 -0.0085 0.0016 -0.0002 0.0000 0.0000 0.0000 S16 -1.3383 -0.1348 0.0526 -0.0128 0.0020 -0.0002 0.0000 0.0000 0.0000 0.0000

[0219] Example 10

[0220] Figure 19 is a view showing a tenth example of an optical imaging system, and Figure 20 shows Figure 19 the aberration curves of the optical imaging system of

[0221] The optical imaging system 110 includes a first lens 1010, a second lens 2010, a third lens 3010, a fourth lens 4010, a fifth lens 5010, a sixth lens 6010, a seventh lens 7010, and an eighth lens 8010.

[0222] The first lens 1010 has a positive refractive power, a convex object side, and a concave image side. The second lens 2010 has a negative refractive power, a convex object side, and a concave image side. The third lens 3010 has a positive refractive power, a convex object side, and a concave image side. The fourth lens 4010 has a negative refractive power, a convex object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the fourth lens 4010. The fifth lens 5010 has a positive refractive power, a concave object side, and a convex image side. The sixth lens 6010 has a positive refractive power, a convex object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the sixth lens 6010. The seventh lens 7010 has a negative refractive power, a concave object side, and a convex image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the seventh lens 7010. The eighth lens 8010 has a negative refractive power, a concave object side, and a concave image side. Additionally, at least one inflection point is formed on either or both of the object side and the image side of the eighth lens 8010.

[0223] The optical imaging system 110 further includes a diaphragm, a filter 9010, and an image sensor 9110. The diaphragm is disposed between the second lens 2010 and the third lens 3010 to adjust the amount of light incident on the image sensor 9110. The filter 9010 is disposed between the eighth lens 8010 and the image sensor 9110 to block infrared rays. The image sensor 9110 forms an imaging surface on which an image of an object is formed. Although Figure 19 not shown in Figure 19 , the diaphragm is disposed at a distance of 1.420 mm from the object side surface of the first lens 1010 toward the imaging surface of the optical imaging system 110. This distance is equal to TTL-SL and can be calculated from the values of TTL and SL in Example 10 listed in Table 21 presented later in this application.

[0224] Table 19 below shows Figure 19 the physical characteristics of the lenses and other elements of the optical imaging system of Figure 19 , and Table 20 below shows Figure 19 the aspherical surface coefficients of the lenses of Figure 19 . Figure 19 Both surfaces of all the lenses of Figure 19 are aspherical.

[0225] Table 19

[0226]

[0227]

[0228] Table 20

[0229] K A B C D E F G H J S1 -1.0644 0.0165 0.0018 -0.0412 0.0886 -0.0911 0.0530 -0.0179 0.0033 -0.0003 S2 5.7701 -0.0359 0.0936 -0.1994 0.2566 -0.2068 0.1044 -0.0321 0.0055 -0.0004 S3 -4.7434 -0.0502 0.0968 -0.2123 0.3323 -0.3304 0.2072 -0.0791 0.0168 -0.0015 S4 -6.5690 -0.0087 -0.0558 0.2039 -0.3571 0.3753 -0.2421 0.0944 -0.0204 0.0019 S5 -9.7869 -0.0454 0.1549 -0.4689 0.7798 -0.8209 0.5452 -0.2206 0.0496 -0.0047 S6 -8.1203 -0.0373 0.0197 -0.0363 0.0310 -0.0276 0.0169 -0.0053 0.0007 0.0000 S7 8.0509 -0.1285 0.1427 -0.3215 0.4824 -0.4619 0.2746 -0.0976 0.0190 -0.0016 S8 -16.5055 -0.1028 0.0934 -0.1654 0.1981 -0.1521 0.0746 -0.0224 0.0037 -0.0003 S9 -27.6061 -0.0266 0.0611 -0.0956 0.0729 -0.0332 0.0098 -0.0019 0.0002 0.0000 S10 -1.2761 0.0702 -0.0651 0.0291 -0.0095 0.0031 -0.0008 0.0001 0.0000 0.0000 S11 -3.6589 0.0559 -0.0802 0.0497 -0.0205 0.0052 -0.0008 0.0001 0.0000 0.0000 S12 8.3323 -0.0069 0.0109 -0.0063 0.0016 -0.0002 0.0000 0.0000 0.0000 0.0000 S13 -4.4601 0.0505 -0.0475 0.0181 -0.0037 0.0005 0.0000 0.0000 0.0000 0.0000 S14 -47.3000 0.1090 -0.1069 0.0482 -0.0122 0.0019 -0.0002 0.0000 0.0000 0.0000 S15 -99.0000 -0.0701 -0.0085 0.0229 -0.0086 0.0016 -0.0002 0.0000 0.0000 0.0000 S16 -1.3322 -0.1340 0.0521 -0.0127 0.0020 -0.0002 0.0000 0.0000 0.0000 0.0000

[0230] In Table 21 below, f is the total focal length of the optical imaging system in mm, TTL is the total length of the optical imaging system in mm (the distance from the object side surface of the first lens to the imaging surface of the optical imaging system), SL is the distance from the diaphragm of the optical imaging system to the imaging surface in mm, F No. is the f-number of the optical imaging system (the total focal length f of the optical imaging system divided by the entrance pupil diameter of the optical imaging system, where both f and the entrance pupil diameter are in mm), IMG HT is the image height on the imaging surface in mm (half of the diagonal length of the imaging surface), and FOV is the field of view angle of the optical imaging system in degrees.

[0231] Although Table 21 below shows specific values, generally, the total focal length f of the optical imaging system can be in the range of 4.0 mm to 5.2 mm, the total length TTL of the optical imaging system can be in the range of 5.0 mm to 6.5 mm, the field of view angle FOV of the optical imaging system can be 76 degrees or greater, and the f-number F No. of the optical imaging system can be less than 2.0.

[0232] Table 21

[0233] Example f TTL SL F No. IMG HT FOV 1 4.388 5.470 4.610 1.900 3.728 79.310 2 4.525 5.500 4.656 1.967 3.728 77.980 3 4.547 5.500 4.645 1.894 3.728 77.990 4 4.464 5.462 4.590 1.786 3.728 78.380 5 4.493 5.493 4.599 1.769 3.728 77.980 6 4.433 5.488 4.572 1.679 3.728 78.732 7 4.309 5.407 4.487 1.596 3.728 80.310 8 5.126 6.499 5.373 1.553 4.200 77.720 9 5.102 6.500 5.345 1.546 4.200 77.720 10 5.095 6.498 5.078 1.490 4.200 77.920

[0234] Table 22 below shows the focal lengths f1, f2, f3, f4, f5, f6, f7, and f8 of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens in mm for each of Examples 1 to 10 described in the present application.

[0235] Although Table 22 below shows specific values, generally, the focal length f1 of the first lens can be in the range of 3.5 mm to 6.0 mm, the focal length f2 of the second lens can be in the range of -12 mm to -8.0 mm, the focal length f3 of the third lens can be in the range of 20 mm to 32 mm, the focal length f5 of the fifth lens can be in the range of 3.0 mm to 6.0 mm, the focal length f6 of the sixth lens can be greater than or equal to 17 mm, and the focal length f8 of the eighth lens can be in the range of -4.0 mm to -2.0 mm.

[0236] Table 22

[0237] Example f1 f2 f3 f4 f5 f6 f7 f8 1 4.215 -10.176 29.645 192.851 3.554 111.853 -150.465 -2.717 2 4.081 -9.162 23.634 152.337 3.736 80.744 -80.158 -2.642 3 4.023 -9.031 24.326 3233.009 3.815 895.716 -281.821 -2.706 4 4.017 -9.189 26.665 -852.360 3.794 593.968 151.765 -2.727 5 4.034 -9.156 27.439 318.073 3.965 69.598 191.678 -2.637 6 4.094 -9.049 23.523 -321.626 4.061 24.608 580.584 -2.583 7 4.157 -9.158 21.620 -115.317 4.041 21.050 167.740 -2.597 8 5.127 -10.792 23.325 -127.525 5.311 18.597 -178.940 -3.200 9 5.112 -10.447 22.808 -164.761 5.324 19.446 -329.440 -3.216 10 5.110 -10.418 22.597 -132.450 5.295 18.928 -366.006 -3.206

[0238] Table 23 shows the thicknesses (L1edgeT), (L2edgeT), (L3edgeT), (L4edgeT), (L5edgeT), (L6edgeT), (L7edgeT), and (L8edgeT) of the edge portions (ribs) of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens in mm for each of Examples 1 to 10 described in the present application.

[0239] Table 23

[0240] Example L1edgeT L2edgeT L3edgeT L4edgeT L5edgeT L6edgeT L7edgeT L8edgeT 1 0.337 0.34 0.265 0.316 0.36 0.568 0.184 0.456 2 0.302 0.344 0.307 0.302 0.364 0.527 0.254 0.374 3 0.261 0.355 0.296 0.312 0.310 0.480 0.231 0.460 4 0.247 0.361 0.291 0.311 0.283 0.463 0.248 0.456 5 0.254 0.346 0.324 0.312 0.297 0.496 0.272 0.398 6 0.244 0.341 0.286 0.322 0.290 0.455 0.297 0.423 7 0.252 0.330 0.240 0.309 0.255 0.406 0.259 0.509 8 0.292 0.411 0.305 0.405 0.272 0.381 0.345 0.797 9 0.300 0.418 0.315 0.405 0.281 0.421 0.344 0.741 10 0.245 0.389 0.322 0.395 0.277 0.404 0.331 0.776

[0241] Table 24 below shows the sag (L5S1 sag) of the object side of the fifth lens, the sag (L5S2 sag) of the image side of the fifth lens, the thickness (Yc82T) at the inflection point on the image side of the eighth lens, and the combined focal length (f345) of the third to fifth lenses in mm for each of Examples 1 to 10 described in the present application.

[0242] Table 24

[0243] Example L5S1 sag L5S2 sag Yc82T f345 1 0.375 0.790 0.590 3.389 2 0.410 0.770 0.590 3.457 3 0.438 0.756 0.705 3.563 4 0.432 0.741 0.725 3.588 5 0.417 0.722 0.680 3.697 6 0.416 0.734 0.690 3.774 7 0.389 0.708 0.720 3.771 8 0.482 0.801 0.870 4.842 9 0.486 0.804 0.850 4.807 10 0.483 0.806 0.860 0.480

[0244] Table 25 below shows the inner diameters in mm of each of the first to eighth spacer rings for each of Examples 1 to 10 described in this application. S1d is the inner diameter of the first spacer ring SP1, S2d is the inner diameter of the second spacer ring SP2, S3d is the inner diameter of the third spacer ring SP3, S4d is the inner diameter of the fourth spacer ring SP4, S5d is the inner diameter of the fifth spacer ring SP5, S6d is the inner diameter of the sixth spacer ring SP6, S7d is the inner diameter of the seventh spacer ring SP7, and S8d is the inner diameter of the eighth spacer ring SP8.

[0245] Table 25

[0246] Example S1d S2d S3d S4d S5d S6d S7d S8d 1 2.320 2.220 2.480 2.890 3.95 5.14 6.06 5.73 2 2.120 2.130 2.420 2.970 3.870 4.890 5.65 - 3 2.240 2.190 2.520 2.960 3.850 4.890 5.54 - 4 2.340 2.290 2.470 2.980 3.770 4.830 5.53 - 5 2.370 2.210 2.470 2.850 3.730 4.920 5.52 - 6 2.470 2.250 2.500 3.040 4.040 5.020 5.62 - 7 2.530 2.310 2.460 2.990 3.820 4.770 5.57 - 8 3.060 2.810 3.100 3.690 4.710 5.790 6.73 - 9 3.060 2.820 3.100 3.590 4.800 5.790 6.49 - 10 3.160 2.740 3.050 3.710 4.730 5.710 6.61 -

[0247] Table 26 below shows, for each of Examples 1 to 10 described in this application, in mm 3 the volumes of each of the first to eighth lenses. L1v is the volume of the first lens, L2v is the volume of the second lens, L3v is the volume of the third lens, L4v is the volume of the fourth lens, L5v is the volume of the fifth lens, L6v is the volume of the sixth lens, L7v is the volume of the seventh lens, and L8v is the volume of the eighth lens.

[0248] Table 26

[0249] Example L1v L2v L3v L4v L5v L6v L7v L8v 1 5.309 5.248 4.706 4.806 12.7176 19.649 12.3864 23.5598 2 5.242 5.046 5.230 5.000 11.834 16.696 15.5578 22.7144 3 4.121 5.477 5.312 4.927 10.642 16.198 14.6022 26.0867 4 5.370 5.618 5.289 5.280 9.594 15.225 14.7372 26.9185 5 5.780 5.525 5.822 5.264 10.666 16.152 13.4873 23.4133 6 6.115 5.784 5.502 5.663 10.456 14.883 14.1524 24.6726 7 6.423 5.947 4.893 5.764 9.669 13.574 13.8487 26.3663 8 11.794 10.320 9.814 11.957 16.126 21.281 24.3849 47.3755 9 12.038 10.577 9.885 12.412 14.015 22.120 24.5267 45.7414 10 11.661 11.228 10.288 13.932 13.896 21.775 24.38 46.5654

[0250] Table 27 below shows the weights in mg of each of the first to eighth lenses for each of Examples 1 to 10 described in this application. L1w is the weight of the first lens, L2w is the weight of the second lens, L3w is the weight of the third lens, L4w is the weight of the fourth lens, L5w is the weight of the fifth lens, L6w is the weight of the sixth lens, L7w is the weight of the seventh lens, and L8w is the weight of the eighth lens.

[0251] Table 27

[0252] Example L1w L2w L3w L4w L5w L6w L7w L8w 1 5.522 6.559 4.894 6.008 13.226 20.435 12.882 24.502 2 5.452 6.307 5.439 6.250 12.308 17.364 16.180 23.623 3 4.285 6.846 5.525 6.159 11.067 16.846 15.186 27.130 4 5.585 7.023 5.501 6.599 9.978 15.834 15.327 27.995 5 6.012 6.906 6.055 6.580 11.093 16.798 14.027 24.350 6 6.360 7.230 5.722 7.079 10.874 15.478 14.718 25.660 7 6.680 7.434 5.088 7.205 10.056 14.116 14.403 27.421 8 12.265 12.899 10.206 14.946 16.771 22.132 25.360 49.271 9 12.519 13.222 10.280 15.514 14.576 23.005 25.508 47.571 10 12.128 14.035 10.700 17.416 14.452 22.646 25.355 48.428

[0253] Table 28 below shows the total outer diameter (including ribs) of each of the first to eighth lenses in millimeters for each of Examples 1 to 10 described in the present application. L1TD is the total outer diameter of the first lens, L2TD is the total outer diameter of the second lens, L3TD is the total outer diameter of the third lens, L4TD is the total outer diameter of the fourth lens, L5TD is the total outer diameter of the fifth lens, L6TD is the total outer diameter of the sixth lens, L7TD is the total outer diameter of the seventh lens, and L8TD is the total outer diameter of the eighth lens.

[0254] Table 28

[0255] Example L1TD L2TD L3TD L4TD L5TD L6TD L7TD L8TD 1 4.120 4.210 4.340 4.520 5.700 6.610 7.100 7.380 2 4.040 4.130 4.270 4.440 5.620 6.530 7.020 7.300 3 4.140 4.230 4.370 4.540 5.720 6.630 6.990 7.280 4 4.240 4.330 4.470 4.640 5.820 6.470 6.960 7.240 5 4.280 4.370 4.510 4.680 5.720 6.370 6.860 7.140 6 4.380 4.470 4.610 4.780 5.820 6.450 6.930 7.220 7 4.440 4.530 4.670 4.840 5.880 6.400 6.890 7.170 8 5.470 5.560 5.690 5.870 7.030 7.550 8.050 8.330 9 5.470 5.560 5.860 6.040 6.490 7.550 8.050 8.350 10 5.590 5.680 5.980 6.160 6.610 7.670 8.030 8.330

[0256] Table 29 below shows the thickness of the flat portion of the ribs of each of the first to eighth lenses in millimeters for each of Examples 1 to 10 described in the present application. L1rt is the thickness of the flat portion of the ribs of the first lens, L2rt is the thickness of the flat portion of the ribs of the second lens, L3rt is the thickness of the flat portion of the ribs of the third lens, L4rt is the thickness of the flat portion of the ribs of the fourth lens, L5rt is the thickness of the flat portion of the ribs of the fifth lens, L6rt is the thickness of the flat portion of the ribs of the sixth lens, L7rt is the thickness of the flat portion of the ribs of the seventh lens, and L8rt is the thickness of the flat portion of the ribs of the eighth lens.

[0257] Table 29

[0258]

[0259]

[0260] Table 30 below shows the numerical values of conditional expressions 1 to 5 for each of Examples 1 to 10 described in the present application.

[0261] Table 30

[0262] Example L1w / L8w S7d / f L1TD / L8TD L1234TDavg / L8TD L12345TDavg / L8TD 1 0.22537 1.38041 0.55827 0.58232 0.62033 2 0.23079 1.24724 0.55342 0.57808 0.61644 3 0.15794 1.21758 0.56868 0.59341 0.63187 4 0.19950 1.23991 0.58564 0.61050 0.64917 5 0.24690 1.22940 0.59944 0.62465 0.65994 6 0.24786 1.26862 0.60665 0.63158 0.66648 7 0.24361 1.29234 0.61925 0.64435 0.67950 8 0.24893 1.31189 0.65666 0.67797 0.71116 9 0.26316 1.27255 0.65509 0.68653 0.70467 10 0.25043 1.29608 0.67107 0.70258 0.72077

[0263] Table 31 below shows the numerical values of conditional expressions 6 to 10 for each of Examples 1 to 10 described in the present application.

[0264] Table 31

[0265] Example (V2+V4) / 2 (V5+V6+V7+V8) / 4 Nd2 Nd4 Nd6 1 19.26 56.11 1.677 1.677 1.546 2 19.26 56.11 1.677 1.677 1.546 3 19.26 56.11 1.677 1.677 1.546 4 19.26 56.11 1.677 1.677 1.546 5 19.26 56.11 1.677 1.677 1.546 6 19.26 56.11 1.677 1.677 1.546 7 19.26 56.11 1.677 1.677 1.546 8 19.26 56.11 1.677 1.677 1.546 9 19.26 56.11 1.677 1.677 1.546 10 19.26 56.11 1.677 1.677 1.546

[0266] Table 32 below shows the numerical values of conditional expressions 11 to 15 for each of Examples 1 to 10 described in the present application.

[0267] Table 32

[0268] Example f1 / f5 f3 / f2 f5 / f8 f5 / f TTL / f1 1 1.1865 -2.9133 -1.3081 0.8092 1.2981 2 1.0924 -2.5795 -1.4141 0.8245 1.3482 3 1.0539 -2.6937 -1.4098 0.8386 1.3676 4 1.0590 -2.9015 -1.3913 0.8505 1.3600 5 1.0171 -2.9967 -1.5036 0.8833 1.3623 6 1.0079 -2.5998 -1.5722 0.9164 1.3409 7 1.0288 -2.3604 -1.5561 0.9376 1.3005 8 0.9654 -2.1612 -1.6597 1.0353 1.2677 9 0.9603 -2.1836 -1.6555 1.0435 1.2720 10 0.9655 -2.1692 -1.6516 1.0378 1.2713

[0269] Table 33 below shows the numerical values of conditional expressions 16 to 20 for each of Examples 1 to 10 described in the present application.

[0270] Table 33

[0271] Example TTL / f5 R7 / R8 R13 / R14 R16 / R1 (R2-R15) / (R1+R16) 1 1.5401 0.9822 0.8856 1.0747 3.6837 2 1.4728 0.9615 0.8230 1.1178 3.4836 3 1.4414 1.0139 0.9324 1.1744 3.4865 4 1.4403 1.0280 1.0857 1.1267 3.7881 5 1.3856 0.9859 1.0622 1.0757 3.9069 6 1.3516 1.0491 1.0044 1.0379 3.9176 7 1.3380 1.1103 1.0672 0.9931 4.1325 8 1.2238 1.1266 0.8956 0.9909 4.1607 9 1.2216 1.1003 0.9333 0.9931 4.2075 10 1.2275 1.1214 0.9380 0.9935 4.1772

[0272] Table 34 below shows the numerical values of conditional expressions 22 to 24 for each of Examples 1 to 10 described in the present application.

[0273] Table 34

[0274] Example R15 / R16 (R7*R9) / (R8*R10) (R7*R10) / (R8*R9) 1 -3.469 4.4728 0.2157 2 -2.726 3.7469 0.2467 3 -2.535 3.9620 0.2595 4 -2.985 3.8608 0.2737 5 -2.916 3.5229 0.2759 6 -2.934 3.7694 0.2920 7 -3.407 4.0425 0.3050 8 -3.370 3.9489 0.3214 9 -3.409 3.8478 0.3146 10 -3.370 3.9703 0.3168

[0275] Figure 21 and Figure 22 is a cross-sectional view of an optical imaging system coupled to a lens barrel.

[0276] Examples of the optical imaging system described in the present application may include a self-aligning structure as Figure 21 and Figure 22 shown.

[0277] In Figure 21 one example shown, the optical imaging system 100 includes a self-aligning structure, wherein by coupling four consecutive lenses 1000, 2000, 3000, and 4000 to each other, the optical axes of the four lenses 1000, 2000, 3000, and 4000 are aligned with the optical axis of the optical imaging system 100.

[0278] The first lens 1000 disposed closest to the object side of the optical imaging system 100 is disposed in contact with the inner surface of the lens barrel 200 to align the optical axis of the first lens 1000 with the optical axis of the optical imaging system 100, the second lens 2000 is coupled to the first lens 1000 to align the optical axis of the second lens 2000 with the optical axis of the optical imaging system 100, the third lens 3000 is coupled to the second lens 2000 to align the optical axis of the third lens 3000 with the optical axis of the optical imaging system 100, and the fourth lens 4000 is coupled to the third lens 3000 to align the optical axis of the fourth lens 4000 with the optical axis of the optical imaging system 100. The second lens 2000 to the fourth lens 4000 may not be in contact with the inner surface of the lens barrel 200, but the fifth lens 5000 to the eighth lens 8000 may be in contact with the inner surface of the lens barrel 200 to align the optical axes of the fifth lens 5000 to the eighth lens 8000 with the optical axis of the optical imaging system 100.

[0279] AlthoughFigure 21 It is shown that the first lens 1000 to the fourth lens 4000 are coupled to each other, but the four consecutive lenses coupled to each other can be changed to the second lens 2000 to the fifth lens 5000, or the third lens 3000 to the sixth lens 6000, or the fourth lens 4000 to the seventh lens 7000, or the fifth lens 5000 to the eighth lens 8000.

[0280] In Figure 22 In another example shown in, the optical imaging system 100 includes a self-aligning structure, wherein by coupling five consecutive lenses 1000, 2000, 3000, 4000, and 5000 to each other, the optical axes of these five lenses 1000, 2000, 3000, 4000, and 5000 are aligned with the optical axis of the optical imaging system 100.

[0281] The first lens 1000 disposed closest to the object side of the optical imaging system 100 is disposed in contact with the inner surface of the lens barrel 200 to align the optical axis of the first lens 1000 with the optical axis of the optical imaging system 100. The second lens 2000 is coupled to the first lens 1000 to align the optical axis of the second lens 2000 with the optical axis of the optical imaging system 100. The third lens 3000 is coupled to the second lens 2000 to align the optical axis of the third lens 3000 with the optical axis of the optical imaging system 100. The fourth lens 4000 is coupled to the third lens 3000 to align the optical axis of the fourth lens 4000 with the optical axis of the optical imaging system 100, and the fifth lens 5000 is coupled to the fourth lens 4000 to align the optical axis of the fifth lens 5000 with the optical axis of the optical imaging system 100. The second lens 2000 to the fifth lens 5000 may not be in contact with the inner surface of the lens barrel 200, but the sixth lens 6000 to the eighth lens 8000 may be in contact with the inner surface of the lens barrel 200 to align the optical axes of the sixth lens 6000 to the eighth lens 8000 with the optical axis of the optical imaging system 100.

[0282] Although Figure 22 It is shown that the first lens 1000 to the fifth lens 5000 are coupled to each other, but the five consecutive lenses coupled to each other can be changed to the second lens 2000 to the sixth lens 6000, or the third lens 3000 to the seventh lens 7000, or the fourth lens 4000 to the eighth lens 8000.

[0283] Figure 23 is a cross-sectional view showing an example of the eighth lens.

[0284] Figure 23Shows the total outer diameter (L8TD) of the eighth lens 8000, the thickness (L8rt) of the flat portion of the rib of the eighth lens 8000, the thickness (L8edgeT) of the edge of the rib of the eighth lens 8000, and the thickness (Yc82T) at the inflection point on the image side of the eighth lens 8000. Although Figure 23 the eighth lens 8000 is shown, the total outer diameter, the thickness of the flat portion of the rib, and the thickness of the edge of the rib of each of the first to seventh lenses are defined in the same manner.

[0285] Figure 24 is a cross-sectional view showing an example of the shape of the rib of the lens.

[0286] An example of the optical imaging system 100 described in the present application may include a structure for preventing a flicker phenomenon and reflection.

[0287] For example, as Figure 24 shown, the ribs of the first to eighth lenses 1000, 2000, 3000, 4000, 5000, 6000, 7000, and 8000 of the optical imaging system 100 may be partially surface-treated to roughen the surface of the ribs. The surface treatment method may include chemical etching, physical polishing, or any other surface treatment method capable of increasing the surface roughness.

[0288] The surface treatment area EA may be formed in the entire area from the edge of the optical portion of the lens to the outer end of the rib, where light actually passes through the optical portion of the lens. However, as Figure 24 shown, the non-treatment area NEA including the step portions E11 and E21 may not be surface-treated, or may be surface-treated to have a roughness less than that of the surface treatment area EA. The step portions E11 and E21 are portions where the thickness of the rib suddenly changes. The width G1 of the first non-treatment area NEA formed on the object side of the lens and including the first step portion E11 may be different from the width G2 of the second non-treatment area NEA formed on the image side of the lens and including the second step portion E21. In Figure 24 the example shown, G1 is greater than G2.

[0289] When viewed in the optical axis direction, the width G1 of the first non-treatment area NEA includes the first step portion E11 and the second step portion E21, and when viewed in the optical axis direction, the width G2 of the second non-treatment area NEA includes the second step portion E21 but does not include the first step portion E11. The distance G4 from the outer end of the rib to the second step portion E21 is less than the distance G3 from the outer end of the rib to the first step portion E11.

[0290] The positions of forming the non-processing area NEA and the stepped portions E11 and E21 as described above can be advantageous for measuring the concentricity of the lens by using test equipment. For example, for a lens having the above shape, since the first stepped portion E11 and the second stepped portion E21 can be recognized by the test equipment, the optical axis of the lens can be accurately aligned by detecting the concentricity of the lens.

[0291] The above examples can miniaturize the optical imaging system and make it easy to correct the aberration.

[0292] 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 can be made to these examples without departing from the spirit and scope of the claims and their equivalents. The examples described in the present application should be considered only in a descriptive sense and not for purposes of limitation. The description of the features or aspects in each example should be considered applicable to similar features or aspects in other examples. Suitable results can also be obtained if the described techniques are performed in a different order, and / or if the components in the described system, architecture, device, or circuit are combined in a different way and / or replaced or supplemented by other components or their equivalents. Therefore, the scope of the present disclosure should not be defined by the detailed description, 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 having a positive refractive power; a second lens having a negative refractive power; a third lens having a concave image side; a fourth lens having a concave image side; a fifth lens having a refractive power; a sixth lens having a refractive power; a seventh lens having a refractive power; and an eighth lens having a negative refractive power, wherein the optical imaging system includes a total of eight lenses having refractive powers, wherein the first lens to the eighth lens are sequentially arranged in numerical order along the optical axis of the optical imaging system from the object side of the optical imaging system toward the imaging surface of the optical imaging system, and wherein the optical imaging system satisfies 0.8 < R16 / R1 < 1.2, where R1 is the radius of curvature of the object side of the first lens, and R16 is the radius of curvature of the image side of the eighth lens.

2. The optical imaging system according to claim 1, wherein the first lens has a convex object side.

3. The optical imaging system according to claim 1, wherein the second lens has a convex object side.

4. The optical imaging system according to claim 1, wherein the third lens has a convex object side.

5. The optical imaging system according to claim 1, wherein the fourth lens has a convex object side.

6. The optical imaging system according to claim 1, wherein the sign of the refractive power of the fifth lens is the same as the sign of the refractive power of the sixth lens.

7. The optical imaging system according to claim 1, wherein the sign of the refractive power of the seventh lens is the same as the sign of the refractive power of the fourth lens.

8. An optical imaging system, comprising: a first lens having a positive refractive power; a second lens having a negative refractive power; a third lens having a positive refractive power and a concave image side; a fourth lens having a refractive power; a fifth lens having a refractive power; a sixth lens having a refractive power; a seventh lens having a refractive power; and an eighth lens having a negative refractive power, wherein the optical imaging system includes a total of eight lenses having refractive powers, wherein the first lens to the eighth lens are sequentially arranged in numerical order along the optical axis of the optical imaging system from the object side of the optical imaging system toward the imaging surface of the optical imaging system, and wherein the optical imaging system satisfies 0.9 < R7 / R8 < 1.2, where R7 is the radius of curvature of the object side of the fourth lens, and R8 is the radius of curvature of the image side of the fourth lens.

9. The optical imaging system according to claim 8, wherein the first lens has a convex object side.

10. The optical imaging system according to claim 8, wherein the second lens has a convex object side.

11. The optical imaging system according to claim 8, wherein the third lens has a convex object side.

12. The optical imaging system according to claim 8, wherein the sign of the refractive power of the seventh lens is the same as the sign of the refractive power of the fourth lens.

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