CN209961991U

CN209961991U - Optical imaging system

Info

Publication number: CN209961991U
Application number: CN201920881603.5U
Authority: CN
Inventors: 孙住和; 任敏爀; 安佳英; 赵镛主
Original assignee: Samsung Electro Mechanics Co Ltd
Current assignee: Samsung Electro Mechanics Co Ltd
Priority date: 2018-06-26
Filing date: 2019-06-12
Publication date: 2020-01-17
Anticipated expiration: 2029-06-12
Also published as: KR20200001452A

Abstract

An optical imaging system comprising: a first lens having a positive refractive power; a second lens having refractive power; a third lens having refractive power; a fourth lens having a refractive power and 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 refractive power and a concave object-side surface, wherein the first lens to the eighth lens are arranged in order in numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging surface of the optical imaging system. The optical imaging system is miniaturized and enables aberrations to be easily corrected.

Description

Optical imaging system

Cross Reference to Related Applications

This application claims the right of priority of korean patent application No. 10-2018-.

Technical Field

The present application relates to an optical imaging system including eight lenses.

Background

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

Accordingly, as the number of mobile terminals provided with cameras has increased, the demand for an optical imaging system capable of improving camera performance without increasing the size of the camera has increased.

SUMMERY OF THE UTILITY MODEL

The summary of the invention is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

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

The second lens may have a negative refractive power.

The object side of the third lens may be convex.

The object side surface of the fifth lens may be concave.

The image side surface of the sixth lens may be convex.

The object side surface of the seventh lens may be concave.

The optical imaging system may 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.

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

The optical imaging system may 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.

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

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

The optical imaging system may satisfy (V2+ V4)/2<20, where V2 is an abbe number of the second lens and V4 is an abbe number of the fourth lens.

The optical imaging system may satisfy 50< (V5+ V6+ V7+ V8)/4, where V5 is an abbe number of the fifth lens, V6 is an abbe number of the sixth lens, V7 is an abbe number of the seventh lens, and V8 is an abbe number of the eighth lens.

The optical imaging system may satisfy 1.6< Nd2<1.8, where Nd2 is a refractive index of the second lens.

The optical imaging system may satisfy 1.6< Nd4<1.8, where Nd4 is a refractive index of the fourth lens.

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

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

Each of the first through fourth lenses may have a convex object side surface and a concave image side surface.

Each of the fifth, seventh, and eighth lenses may have a concave object-side surface, the seventh lens may have a convex image-side surface, and the eighth lens may have a concave image-side surface.

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

The optical imaging system is miniaturized and enables aberrations to be easily corrected.

Other features and aspects will be apparent from the following detailed description, the accompanying drawings, and the claims.

Drawings

Fig. 1 is a view showing a first example of an optical imaging system.

Fig. 2 shows an aberration curve of the optical imaging system of fig. 1.

Fig. 3 is a view showing a second example of the optical imaging system.

Figure 4 shows an aberration curve for the optical imaging system of figure 3.

Fig. 5 is a view showing a third example of the optical imaging system.

Figure 6 shows an aberration curve for the optical imaging system of figure 5.

Fig. 7 is a view showing a fourth example of the optical imaging system.

Figure 8 shows an aberration curve for the optical imaging system of figure 7.

Fig. 9 is a view showing a fifth example of the optical imaging system.

Figure 10 shows an aberration curve for the optical imaging system of figure 9.

Fig. 11 is a view showing a sixth example of the optical imaging system.

Fig. 12 shows an aberration curve of the optical imaging system of fig. 11.

Fig. 13 is a view showing a seventh example of the optical imaging system.

Fig. 14 shows an aberration curve of the optical imaging system of fig. 13.

Fig. 15 is a view showing an eighth example of the optical imaging system.

Fig. 16 shows an aberration curve of the optical imaging system of fig. 15.

Fig. 17 is a view showing a ninth example of the optical imaging system.

Fig. 18 shows an aberration curve of the optical imaging system of fig. 17.

Fig. 19 is a view showing a tenth example of the optical imaging system.

Fig. 20 shows an aberration curve of the optical imaging system of fig. 19.

Fig. 21 and 22 are sectional views of an optical imaging system coupled to a lens barrel.

Fig. 23 is a sectional view showing an example of an eighth lens.

Fig. 24 is a sectional view showing an example of the shape of a rib of the lens.

Like reference numerals refer to like elements throughout the drawings and detailed description. The figures may not be drawn to scale and the relative sizes, proportions and depictions of the elements in the figures may be exaggerated for clarity, illustration and convenience.

Detailed Description

The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, devices, and/or systems described herein. Various changes, modifications, and equivalents of the methods, devices, and/or systems described in this application will, however, become apparent after understanding the disclosure of this application. For example, the order of operations described in this application is merely an example, and is not limited to the order set forth in this application, except as operations that must occur in a particular order, but rather obvious variations may be made upon understanding the disclosure of this application. In addition, descriptions of features well known in the art may be omitted for the sake of clarity and conciseness.

The features described in this application may be embodied in different forms and should not be construed as limited to the examples described in this application. Rather, the examples described herein are provided merely to illustrate some of the many possible ways to implement the methods, apparatuses, and/or systems described herein, which will be apparent after understanding the disclosure of the present application.

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, it can be directly on, "connected to" or "coupled to" the other element or one or more other elements may be present between the element and the other element. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element, there may be no other elements intervening between the element and the other element.

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

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

Spatially relative terms such as "above … …", "above", "below … …" and "below" may be used herein for descriptive convenience to describe one element's relationship to another element as illustrated in the figures. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "upper" relative to other elements would then be oriented "below" or "lower" relative to the other elements. Thus, the phrase "above … …" encompasses both an orientation of "above. The device may also be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used in this application should be interpreted accordingly.

The terminology used in the present application is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. The articles "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, integers, operations, elements, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, operations, elements, components, and/or groups thereof.

The thickness, size, and shape of the lens shown in the drawings may be slightly exaggerated for convenience of explanation. In addition, the shapes of the spherical surface or the aspherical surface of the lens described in the detailed description and shown in the detailed description or the drawings are merely examples. That is, the shape of the spherical surface or the aspherical surface of the lens is not limited to the examples described in the present application.

The values of the radius of curvature, thickness, distance between elements including the lens or surface, effective half aperture of the lens, focal length, and diameter, thickness and length of the various elements are expressed in millimeters (mm), while the angles are expressed in degrees. The thickness of the lens and the distance between elements comprising the lens or surface are measured along the optical axis of the optical imaging system.

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

In the present application, unless otherwise specified, reference to the shape of a lens surface refers to the shape of the paraxial region of the lens surface. The paraxial region of the lens surface is a central portion of the lens surface around an optical axis of the lens surface, wherein a ray incident to the lens surface forms a small angle θ with the optical axis, and the following is approximately valid: sin θ ≈ θ, tan θ ≈ θ, and cos θ ≈ 1.

For example, the expression that the object side of the lens is convex means that at least the paraxial region of the object side of the lens is convex, and the expression that the image side of the lens is concave means that at least the paraxial region of the image side of the lens is concave. Thus, even though the object side surface of the lens may be described as convex, the entire object side surface of the lens may not be convex, and the edge region of the object side surface of the lens may be concave. Meanwhile, even though the image side surface of the lens may be described as concave, the entire image side surface of the lens may not be concave, and an edge region of the image side surface of the lens may be convex.

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

The optical imaging system includes a multi-piece lens. 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 that are arranged in order in numerical order from the object side of the optical imaging system toward the imaging surface of the optical imaging system along the optical axis 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 plane.

Each lens of the optical imaging system includes an optical portion and a rib. The optical portion of the lens is a portion of the lens configured to refract light, and is generally formed in a central portion of the lens. The rib of the lens is an edge portion of the lens that enables the lens to be mounted in the lens barrel with the optical axis of the lens aligned with the optical axis of the optical imaging system. The ribs of the lens extend radially outward from the optic portion. The optical portions of the lens are typically not in contact with each other. For example, the first to eighth lenses 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 lens may selectively contact each other. For example, the ribs of the first to fourth lenses, or the ribs of the first to fifth lenses, or the ribs of the second to fourth lenses may contact each other so that the optical axes of these lenses may be easily aligned with the optical axis of the optical imaging system.

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

The optical imaging system further comprises a diaphragm and a spacer ring. The stop is disposed in front of the first lens, or between two adjacent lenses of the first to eighth lenses, or between an object-side surface and an image-side surface of one of the first to eighth lenses, to adjust an amount of light incident on the imaging surface. Each of the spacers is disposed at a corresponding position between two lenses of the first to eighth lenses to maintain a predetermined distance between the two lenses. In addition, the spacer may be made of a light blocking material to block external light penetrating into the rib of the lens. There may be seven or eight spacing rings. For example, a first spacer is disposed between the first lens and the second lens, a second spacer is disposed between the second lens and the third lens, a third spacer is disposed between the third lens and the fourth lens, a fourth spacer is disposed between the fourth lens and the fifth lens, a fifth spacer is disposed between the fifth lens and the sixth lens, a sixth spacer is disposed between the sixth lens and the seventh lens, and a seventh spacer is disposed between the seventh lens and the eighth lens. In addition, the optical imaging system may further include an eighth spacer disposed between the seventh lens and the seventh spacer.

Next, the lens of the optical imaging system will be described.

The first lens has a refractive power. For example, the first lens may have a positive refractive power. One face of the first lens may be convex. For example, the object side of the first lens may be convex. One face of the first lens may be concave. For example, the image side surface of the first lens may be concave. The first lens may have an aspherical surface. For example, one or both faces of the first lens may be aspherical.

The second lens has a refractive power. For example, the second lens may have a negative refractive power. One face of the second lens may be convex. For example, the object side of the second lens may be convex. One face 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 aspheric surface. For example, one or both faces of the second lens may be aspherical.

The third lens has a refractive power. For example, the third lens may have a positive refractive power. One face of the third lens may be convex. For example, the object side of the third lens may be convex. One face 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 faces of the third lens may be aspherical.

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 of the fourth lens may be convex. One face 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. The point of inflection is the point at which 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. Accordingly, at least one face of the fourth lens may have a paraxial region and an edge region that are different in shape from each other. For example, a paraxial region of the object side surface of the fourth lens may be convex, but an 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 faces of the fourth lens may be aspherical.

The fifth lens has refractive power. For example, the fifth lens may have a positive refractive power. One face 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 faces of the fifth lens may be aspherical.

The sixth lens has 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 face 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 or both of the object-side surface and the image-side surface of the sixth lens. Accordingly, at least one face of the sixth lens may have a paraxial region and an edge region which are different in shape from each other. For example, a paraxial region of the object side surface of the sixth lens may be concave, but an edge 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 faces of the sixth lens may be aspherical.

The seventh lens has a refractive power. For example, the seventh lens may have a positive refractive power or a negative refractive power. One face 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 or both of the object-side surface and the image-side surface of the seventh lens. Accordingly, at least one face of the seventh lens may have a paraxial region and an edge region which are different in shape from each other. For example, a paraxial region of the object side surface of the seventh lens may be concave, but an edge 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 faces of the seventh lens may be aspherical.

The eighth lens has refractive power. For example, the eighth lens may have a negative refractive power. Both faces 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 or both of the object-side surface and the image-side surface of the eighth lens. Accordingly, at least one face of the eighth lens may have a paraxial region and an edge region which are different in shape from each other. For example, a paraxial region of the object side surface of the eighth lens may be concave, but an edge 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 faces of the eighth lens may be aspherical.

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

The aspherical surfaces of the first to eighth lenses may be represented by the following equation 1:

in equation 1, c is a curvature of the lens surface and is equal to an inverse of a curvature radius of the lens surface at an optical axis of the lens surface, K is a conic constant, Y is a distance from a certain point on an aspherical surface of the lens to the optical axis of the lens in a direction perpendicular to the optical axis, a to H are aspherical constants, and Z (or sag) is a distance between a certain point on the aspherical surface of the lens where the distance to the optical axis is Y and a tangent plane perpendicular to the optical axis that intersects with a vertex of the aspherical surface of the lens. Examples disclosed in this application also include an aspheric constant J. Additional items JY²⁰May be added to the right side of equation 1 to reflect the effect of the aspheric constant J.

The optical imaging system may satisfy one or more of the following conditional expressions 1 to 24.

0.1< L1w/L8w <0.3 (conditional expression 1)

1.0< S7d/f <1.4 (conditional expression 2)

0.4< L1TD/L8TD <0.8 (conditional expression 3)

0.4< L1234TDavg/L8TD <0.8 (conditional expression 4)

0.5< L12345TDavg/L8TD <0.8 (conditional expression 5)

(V2+ V4)/2<20 (conditional expression 6)

50< (V5+ V6+ V7+ V8)/4 (conditional expression 7)

1.6< Nd2<1.8 (conditional expression 8)

1.6< Nd4<1.8 (conditional expression 9)

Nd6<1.6 (conditional expression 10)

0.8< f1/f5<1.4 (conditional expression 11)

-4.0< f3/f2< -2.0 (conditional expression 12)

-2.0< f5/f8< -1.0 (conditional expression 13)

0.7< f5/f <1.2 (conditional expression 14)

1.0< TTL/f1<1.4 (conditional expression 15)

1.0< TTL/f5<1.8 (conditional expression 16)

0.9< R7/R8<1.2 (conditional expression 17)

0.8< R13/R14<1.2 (conditional expression 18)

0.8< R16/R1<1.2 (conditional expression 19)

3.4< (R2-R15)/(R1+ R16) <5.0 (conditional expression 20)

LT4< LT3 or LT4< LT5 (conditional expression 21)

2.0< | R15/R16| <5.0 (conditional expression 22)

3.0< (R7R 9)/(R8R 10) <5.0 (conditional expression 23)

0.2< (R7R 10)/(R8R 9) <0.4 (conditional expression 24)

In the above conditional expressions, L1w is the weight of the first lens in mg, and L8w is the weight of the eighth lens in mg.

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

L1TD is the overall outer diameter of the first lens in mm, and L8TD is the overall outer diameter of the eighth lens in mm. The overall outer diameter of the lens is the diameter of the lens (including the optical portion of the lens and the ribs of the lens).

L1234TDavg is an average of the total outer diameters of the first to fourth lenses in mm, and L12345TDavg is an average of the total outer diameters of the first to fifth lenses in mm.

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.

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.

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

r1 is a radius of curvature of an object-side surface of the first lens element in mm, R2 is a radius of curvature of an image-side surface of the first lens element in mm, R7 is a radius of curvature of an object-side surface of the fourth lens element in mm, R8 is a radius of curvature of an image-side surface of the fourth lens element in mm, R9 is a radius of curvature of an object-side surface of the fifth lens element in mm, R10 is a radius of curvature of an image-side surface of the fifth lens element in mm, R13 is a radius of curvature of an object-side surface of the seventh lens element in mm, R14 is a radius of curvature of an image-side surface of the seventh lens element in mm, R15 is a radius of curvature of an object-side surface of the eighth lens element in mm, and R16 is a radius of curvature of an image-side surface of the eighth lens element in mm.

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.

Conditional expressions 1 and 3 specify a range of the weight ratio and a range of the total outer diameter ratio between the first lens and the eighth lens to facilitate self-alignment between the lenses and alignment of the lenses with the lens barrel.

Conditional expression 2 specifies a range of the ratio of the inner diameter of the seventh space ring to the total focal length of the optical imaging system to minimize the flare phenomenon.

Conditional expressions 4 and 5 specify the total outer diameter ratio between lenses to facilitate aberration correction.

The optical imaging system may satisfy conditional expression 10 while satisfying conditional expression 8 or 9.

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

Example 1

Fig. 1 is a view showing a first example of an optical imaging system, and fig. 2 shows an aberration curve of the optical imaging system of fig. 1.

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.

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. In addition, 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. In addition, 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 element 6001. The seventh lens 7001 has a negative refractive power, a concave object-side surface, and a convex image-side surface. In addition, 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. In addition, 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.

The optical imaging system 101 further includes a diaphragm, an optical filter 9001 and an image sensor 9101. A stop is provided between the first lens 1001 and the second lens 2001 to adjust the amount of light incident on the image sensor 9101. The optical 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 a subject is formed. Although not shown in fig. 1, the stop is disposed at a distance of 0.860mm 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 of example 1 listed in table 21 presented later in this application.

Table 1 below shows physical characteristics of the lens and other elements of the optical imaging system of fig. 1, and table 2 below shows aspherical surface coefficients of the lens of fig. 1. Both faces of all the lenses of fig. 1 are aspherical.

TABLE 1

TABLE 2

	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

Example 2

Fig. 3 is a view showing a second example of the optical imaging system, and fig. 4 shows an aberration curve of the optical imaging system of fig. 3.

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.

First lens 1002 has a positive refractive power, a convex object side surface, and a concave image side surface. The second lens 2002 has a negative refractive power, a convex object side surface, and a concave image side surface. The third lens 3002 has a positive refractive power, a convex object side surface and a concave image side surface. The fourth lens 4002 has a positive refractive power, a convex object-side surface, and a concave image-side surface. In addition, 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 4002. The fifth lens 5002 has a positive refractive power, a concave object-side surface, and a convex image-side surface. The sixth lens 6002 has a positive refractive power, a concave object side surface, and a convex image side surface. In addition, 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 6002. The seventh lens 7002 has a negative refractive power, a concave object side surface, and a convex image side surface. In addition, 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 7002. The eighth lens 8002 has a negative refractive power, a concave object side surface, and a concave image side surface. In addition, 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 8002.

The optical imaging system 102 further includes a diaphragm, an optical filter 9002 and an image sensor 9102. A diaphragm is provided between the first lens 1002 and the second lens 2002 to adjust the amount of light incident on the image sensor 9102. An optical filter 9002 is disposed between the eighth lens 8002 and the image sensor 9102 to block infrared rays. The image sensor 9102 forms an image forming surface on which an image of a subject is formed. Although not shown in fig. 3, the stop is disposed at a distance of 0.844mm from the object-side surface 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 of example 2 listed in table 21 presented later in this application.

Table 3 below shows physical characteristics of the lens and other elements of the optical imaging system of fig. 3, and table 4 below shows aspherical surface coefficients of the lens of fig. 3. Both faces of all the lenses of fig. 3 are aspherical. TABLE 3

TABLE 4

Example 3

Fig. 5 is a view showing a third example of the optical imaging system, and fig. 6 shows an aberration curve of the optical imaging system of fig. 5.

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.

The first lens 1003 has a positive refractive power, a convex object side surface, and a concave image side surface. The second lens 2003 has a negative refractive power, a convex object side surface and a concave image side surface. The third lens 3003 has a positive refractive power, a convex object side surface and a concave image side surface. The fourth lens 4003 has a positive refractive power, a convex object side surface, and a concave image side surface. In addition, 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 4003. The fifth lens 5003 has positive refractive power, a concave object-side surface, and a convex image-side surface. The sixth lens 6003 has a positive refractive power, a concave object side surface, and a convex image side surface. In addition, 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 6003. The seventh lens 7003 has a negative refractive power, a concave object side surface, and a convex image side surface. In addition, 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 7003. The eighth lens 8003 has a negative refractive power, a concave object side surface, and a concave image side surface. In addition, 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 8003.

The optical imaging system 103 further includes a diaphragm, an optical filter 9003, and an image sensor 9103. A stop is provided between the first lens 1003 and the second lens 2003 to adjust the amount of light incident on the image sensor 9103. An optical filter 9003 is disposed between the eighth lens 8003 and the image sensor 9103 to block infrared rays. The image sensor 9103 forms an image forming surface on which an image of a subject is formed. Although not shown in fig. 5, the stop is disposed at a distance of 0.855mm from the object side surface of the first lens 1003 toward the imaging plane 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.

Table 5 below shows physical characteristics of the lens and other elements of the optical imaging system of fig. 5, and table 6 below shows aspherical surface coefficients of the lens of fig. 5. Both faces of all the lenses of fig. 5 are aspherical.

TABLE 5

TABLE 6

Example 4

Fig. 7 is a view showing a fourth example of the optical imaging system, and fig. 8 shows an aberration curve of the optical imaging system of fig. 7.

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.

The first lens 1004 has a positive refractive power, a convex object side surface, and a concave image side surface. Second lens 2004 has a negative refractive power, a convex object side surface, and a concave image side surface. The third lens 3004 has a positive refractive power, a convex object side surface and a concave image side surface. The fourth lens 4004 has a negative refractive power, a convex object-side surface, and a concave image-side surface. In addition, 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 4004. The fifth lens 5004 has a positive refractive power, a concave object-side surface, and a convex image-side surface. The sixth lens 6004 has a positive refractive power, a concave object side surface, and a convex image side surface. In addition, 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 6004. The seventh lens 7004 has positive refractive power, a concave object side surface, and a convex image side surface. In addition, 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 7004. The eighth lens 8004 has a negative refractive power, a concave object side surface, and a concave image side surface. In addition, 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 8004.

The optical imaging system 104 further includes a diaphragm, an optical filter 9004 and an image sensor 9104. A stop is provided between the first lens 1004 and the second lens 2004 to adjust the amount of light incident on the image sensor 9104. An optical filter 9004 is disposed between the eighth lens 8004 and the image sensor 9104 to block infrared rays. The image sensor 9104 forms an image forming surface on which an image of a subject is formed. Although not shown in fig. 7, the stop is disposed at a distance of 0.872mm 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 of example 4 listed in table 21 presented later in this application.

Table 7 below shows physical characteristics of the lens and other elements of the optical imaging system of fig. 7, and table 8 below shows aspherical surface coefficients of the lens of fig. 7. Both faces of all the lenses of fig. 7 are aspherical.

TABLE 7

TABLE 8

Example 5

Fig. 9 is a view showing a fifth example of the optical imaging system, and fig. 10 shows an aberration curve of the optical imaging system of fig. 9.

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.

The first lens 1005 has a positive refractive power, a convex object side surface, and a concave image side surface. The second lens 2005 has a negative refractive power, a convex object-side surface, and a concave image-side surface. The third lens 3005 has a positive refractive power, a convex object side surface and a concave image side surface. The fourth lens 4005 has a positive refractive power, a convex object-side surface, and a concave image-side surface. In addition, 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 4005. The fifth lens 5005 has a positive refractive power, a concave object-side surface, and a convex image-side surface. The sixth lens 6005 has a positive refractive power, a concave object side surface, and a convex image side surface. In addition, 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 6005. The seventh lens 7005 has positive refractive power, a concave object side surface, and a convex image side surface. In addition, 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 7005. The eighth lens 8005 has a negative refractive power, a concave object side surface, and a concave image side surface. In addition, 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 8005.

The optical imaging system 105 further includes a diaphragm, an optical filter 9005 and an image sensor 9105. A stop is disposed between the first lens 1005 and the second lens 2005 to adjust the amount of light incident on the image sensor 9105. An optical 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 a subject is formed. Although not shown in fig. 9, the stop is disposed at a distance of 0.894mm from the object-side surface 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 of example 5 listed in table 21 presented later in this application.

Table 9 below shows physical characteristics of the lens and other elements of the optical imaging system of fig. 9, and table 10 below shows aspherical surface coefficients of the lens of fig. 9. Both faces of all the lenses of fig. 9 are aspherical.

TABLE 9

Watch 10

Example 6

Fig. 11 is a view showing a sixth example of the optical imaging system, and fig. 12 shows an aberration curve of the optical imaging system of fig. 11.

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.

First lens 1006 has a positive refractive power, a convex object-side surface, and a concave image-side surface. The second lens 2006 has a negative refractive power, a convex object side surface and a concave image side surface. The third lens 3006 has a positive refractive power, a convex object side surface and a concave image side surface. The fourth lens 4006 has a negative refractive power, a convex object side surface, and a concave image side surface. In addition, 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 4006. The fifth lens 5006 has a positive refractive power, a concave object-side surface, and a convex image-side surface. The sixth lens 6006 has a positive refractive power, a concave object side surface, and a convex image side surface. In addition, 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 6006. The seventh lens 7006 has positive refractive power, a concave object side surface, and a convex image side surface. In addition, 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 7006. The eighth lens 8006 has a negative refractive power, a concave object side surface, and a concave image side surface. In addition, 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 8006.

The optical imaging system 106 further includes a diaphragm, an optical filter 9006 and an image sensor 9106. A stop is provided between the first lens 1006 and the second lens 2006 to adjust the amount of light incident on the image sensor 9106. An optical 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 a subject is formed. Although not shown in fig. 11, the stop is disposed at a distance of 0.916mm from the object side surface 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.

Table 11 below shows physical characteristics of the lens and other elements of the optical imaging system of fig. 11, and table 12 below shows aspherical surface coefficients of the lens of fig. 11. Both faces of all the lenses of fig. 11 are aspherical.

TABLE 11

TABLE 12

	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

Example 7

Fig. 13 is a view showing a seventh example of the optical imaging system, and fig. 14 shows an aberration curve of the optical imaging system of fig. 13.

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.

The first lens 1007 has a positive refractive power, a convex object side surface, and a concave image side surface. The second lens 2007 has a negative refractive power, a convex object-side surface and a concave image-side surface. The third lens 3007 has a positive refractive power, a convex object side surface and a concave image side surface. The fourth lens 4007 has a negative refractive power, a convex object side surface, and a concave image side surface. In addition, 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 4007. The fifth lens 5007 has a positive refractive power, a concave object-side surface, and a convex image-side surface. The sixth lens 6007 has a positive refractive power, a concave object side surface, and a convex image side surface. In addition, 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 6007. The seventh lens 7007 has positive refractive power, a concave object side surface, and a convex image side surface. In addition, 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 7007. The eighth lens 8007 has a negative refractive power, a concave object side surface, and a concave image side surface. In addition, 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 8007.

The optical imaging system 107 further includes a diaphragm, an optical filter 9007 and an image sensor 9107. A 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 optical filter 9007 is disposed between the eighth lens 8007 and the image sensor 9107 to block infrared rays. The image sensor 9107 forms an image forming surface on which an image of a subject is formed. Although not shown in fig. 13, the stop is disposed at a distance of 0.920mm 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 of example 7 listed in table 21 presented later in this application.

Table 13 below shows physical characteristics of the lens and other elements of the optical imaging system of fig. 13, and table 14 below shows aspherical surface coefficients of the lens of fig. 13. Both faces of all the lenses of fig. 13 are aspherical.

Watch 13

TABLE 14

	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

Example 8

Fig. 15 is a view showing an eighth example of the optical imaging system, and fig. 16 shows an aberration curve of the optical imaging system of fig. 15.

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.

First lens 1008 has a positive refractive power, a convex object side surface and a concave image side surface. The second lens 2008 has a negative refractive power, a convex object-side surface, and a concave image-side surface. The third lens 3008 has a positive refractive power, a convex object side surface and a concave image side surface. The fourth lens 4008 has a negative refractive power, a convex object side surface, and a concave image side surface. In addition, 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 4008. The fifth lens 5008 has a positive refractive power, a concave object-side surface, and a convex image-side surface. The sixth lens 6008 has a positive refractive power, a convex object side surface, and a convex image side surface. In addition, 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 6008. The seventh lens 7008 has a negative refractive power, a concave object side surface, and a convex image side surface. In addition, 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 7008. The eighth lens 8008 has a negative refractive power, a concave object side surface, and a concave image side surface. In addition, 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 8008.

The optical imaging system 108 also includes a diaphragm, an optical filter 9008 and an image sensor 9108. A diaphragm is provided between the first lens 1008 and the second lens 2008 to adjust the amount of light incident on the image sensor 9108. An optical filter 9008 is disposed between the eighth lens 8008 and the image sensor 9108 to block infrared rays. The image sensor 9108 forms an image forming surface on which an image of a subject is formed. Although not shown in fig. 15, the stop is disposed at a distance of 1.126mm from the object side surface 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 of example 8 listed in table 21 presented later in this application.

Table 15 below shows physical characteristics of the lens and other elements of the optical imaging system of fig. 15, and table 16 below shows aspherical surface coefficients of the lens of fig. 15. Both faces of all the lenses of fig. 15 are aspherical.

Watch 15

TABLE 16

	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

Example 9

Fig. 17 is a view showing a ninth example of the optical imaging system, and fig. 18 shows an aberration curve of the optical imaging system of fig. 17.

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.

The first lens 1009 has a positive refractive power, a convex object side surface, and a concave image side surface. The second lens 2009 has a negative refractive power, a convex object-side surface and a concave image-side surface. The third lens 3009 has a positive refractive power, a convex object side surface and a concave image side surface. The fourth lens 4009 has a negative refractive power, a convex object-side surface, and a concave image-side surface. In addition, 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 4009. The fifth lens 5009 has a positive refractive power, a concave object-side surface, and a convex image-side surface. The sixth lens 6009 has a positive refractive power, a convex object side surface, and a convex image side surface. In addition, 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 6009. The seventh lens 7009 has a negative refractive power, a concave object side surface, and a convex image side surface. In addition, 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 7009. The eighth lens 8009 has a negative refractive power, a concave object side surface, and a concave image side surface. In addition, 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 8009.

The optical imaging system 109 further includes a diaphragm, an optical filter 9009 and an image sensor 9109. A stop is provided between the first lens 1009 and the second lens 2009 to adjust the amount of light incident on the image sensor 9109. An optical filter 9009 is disposed between the eighth lens 8009 and the image sensor 9109 to block infrared rays. The image sensor 9109 forms an image forming surface on which an image of a subject is formed. Although not shown in fig. 17, the stop is disposed at a distance of 1.155mm from the object-side surface 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.

Table 17 below shows physical characteristics of the lens and other elements of the optical imaging system of fig. 17, and table 18 below shows aspherical surface coefficients of the lens of fig. 17. Both faces of all the lenses of fig. 17 are aspherical.

TABLE 17

Watch 18

	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

Example 10

Fig. 19 is a view showing a tenth example of the optical imaging system, and fig. 20 shows an aberration curve of the optical imaging system of fig. 19.

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.

The first lens 1010 has a positive refractive power, a convex object side surface, and a concave image side surface. The second lens 2010 has a negative refractive power, a convex object side surface and a concave image side surface. Third lens 3010 has a positive refractive power, a convex object-side surface, and a concave image-side surface. The fourth lens 4010 has a negative refractive power, a convex object-side surface, and a concave image-side surface. In addition, 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 surface, and a convex image side surface. The sixth lens 6010 has a positive refractive power, a convex object side surface, and a convex image side surface. In addition, 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 6010. The seventh lens 7010 has a negative refractive power, a concave object-side surface, and a convex image-side surface. In addition, 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 7010. The eighth lens 8010 has a negative refractive power, a concave object side surface, and a concave image side surface. In addition, 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 8010.

The optical imaging system 110 further includes a diaphragm, an optical filter 9010, and an image sensor 9110. A 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 a subject is formed. Although not shown in fig. 19, the stop is disposed at a distance of 1.420mm 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 of example 10 listed in table 21 presented later in this application.

Table 19 below shows physical characteristics of the lens and other elements of the optical imaging system of fig. 19, and table 20 below shows aspherical surface coefficients of the lens of fig. 19. Both faces of all the lenses of fig. 19 are aspherical.

Watch 19

Watch 20

	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

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

Although table 21 below shows specific values, in general, the total focal length F of the optical imaging system may be in the range of 4.0mm to 5.2mm, the total length TTL of the optical imaging system may be in the range of 5.0mm to 6.5mm, the field angle FOV of the optical imaging system may be 76 degrees or more, and the F-number F No. of the optical imaging system may be less than 2.0.

TABLE 21

Examples of the invention	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

Table 22 below shows the focal length f1 of the first lens, the focal length f2 of the second lens, the focal length f3 of the third lens, the focal length f4 of the fourth lens, the focal length f5 of the fifth lens, the focal length f6 of the sixth lens, the focal length f7 of the seventh lens, and the focal length f8 of the eighth lens, in mm, for each of examples 1 to 10 described herein.

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

TABLE 22

Examples of the invention	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

Table 23 shows the thickness (L1edgeT) of the edge portion (rib) of the first lens, the thickness (L2edgeT) of the edge portion (rib) of the second lens, the thickness (L3edgeT) of the edge portion (rib) of the third lens, the thickness (L4edgeT) of the edge portion (rib) of the fourth lens, the thickness (L5edgeT) of the edge portion (rib) of the fifth lens, the thickness (L6edgeT) of the edge portion (rib) of the sixth lens, the thickness (L7edgeT) of the edge portion (rib) of the seventh lens, and the thickness (L8edgeT) of the edge portion (rib) of the eighth lens, expressed in mm, for each of examples 1 to 10 described in the present application.

TABLE 23

Examples of the invention	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

Table 24 below shows sag of the object-side surface of the fifth lens (L5S1sag), sag of the image-side surface of the fifth lens (L5S2sag), the thickness of the eighth lens at the inflection point on the image-side surface of the eighth lens (Yc82T), and the combined focal length of the third lens to the fifth lens (f345) in mm for each of examples 1 to 10 described in the present application.

Watch 24

Examples of the invention	L5S1sag	L5S2sag	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

Table 25 below shows the inner diameter of each of the first to eighth spacers in mm for each of examples 1 to 10 described in the present application. S1d is the inner diameter of first space ring SP1, S2d is the inner diameter of second space ring SP2, S3d is the inner diameter of third space ring SP3, S4d is the inner diameter of fourth space ring SP4, S5d is the inner diameter of fifth space ring SP5, S6d is the inner diameter of sixth space ring SP6, S7d is the inner diameter of seventh space ring SP7, and S8d is the inner diameter of eighth space ring SP 8.

TABLE 25

Examples of the invention	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	–

Table 26 below shows the values in mm for each of examples 1 to 10 described in the present application³The volume of each of the first through eighth lenses shown. 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.

Watch 26

Examples of the invention	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

Table 27 below shows the weight of each of the first to eighth lenses in mg for each of examples 1 to 10 described in the present 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.

Watch 27

Examples of the invention	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

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

Watch 28

Examples of the invention	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

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

Watch 29

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

Watch 30

Examples of the invention	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

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

Watch 31

Examples of the invention	(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

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

Watch 32

Examples of the invention	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

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

Watch 33

Examples of the invention	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

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

Watch 34

Examples of the invention	R15/R16	(R7R9)/(R8R10)	(R7R10)/(R8R9)
				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

Examples of optical imaging systems described in the present application may include self-aligned structures as shown in fig. 21 and 22.

In one example shown in fig. 21, the optical imaging system 100 includes a self-aligning structure in which optical axes of four

consecutive lenses

1000, 2000, 3000, and 4000 are aligned with an optical axis of the optical imaging system 100 by coupling the four

lenses

1000, 2000, 3000, and 4000 to each other.

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

Although fig. 21 shows that the first through fourth lenses 1000 through 4000 are coupled to each other, four consecutive lenses coupled to each other may be changed to the second through fifth lenses 2000 through 5000, or the third through sixth lenses 3000 through 6000, or the fourth through seventh lenses 4000 through 7000, or the fifth through eighth lenses 5000 through 8000.

In another example shown in fig. 22, the optical imaging system 100 includes a self-aligning structure in which optical axes of five

consecutive lenses

1000, 2000, 3000, 4000, and 5000 are aligned with an optical axis of the optical imaging system 100 by coupling the five

lenses

1000, 2000, 3000, 4000, and 5000 to each other.

The first lens 1000 disposed closest to the object side of the optical imaging system 100 is disposed in contact with an inner surface of the lens barrel 200 to align an optical axis of the first lens 1000 with an optical axis of the optical imaging system 100, the second lens 2000 is coupled to the first lens 1000 to align an 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 an 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 an 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 an optical axis of the fifth lens 5000 with the optical axis of the optical imaging system 100. The second to fifth lenses 2000 to 5000 may not contact with the inner surface of the lens barrel 200, but the sixth to eighth lenses 6000 to 8000 may contact with the inner surface of the lens barrel 200 to align the optical axes of the sixth to eighth lenses 6000 to 8000 with the optical axis of the optical imaging system 100.

Although fig. 22 shows that the first through fifth lenses 1000 through 5000 are coupled to each other, five consecutive lenses coupled to each other may be changed to the second through sixth lenses 2000 through 6000, or the third through seventh lenses 3000 through 7000, or the fourth through eighth lenses 4000 through 8000.

Fig. 23 is a sectional view showing an example of an eighth lens.

Fig. 23 shows 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 (L8edge t) of the edge of the rib of the eighth lens 8000, and the thickness (Yc82T) of the eighth lens 8000 at the point of inflection on the image-side surface of the eighth lens 8000. Although fig. 23 shows the eighth lens 8000, the total outer diameter of each of the first to seventh lenses, the thickness of the flat portion of the rib, and the thickness of the edge of the rib are defined in the same manner.

Examples of the optical imaging system 100 described in the present application may include structures for preventing a flicker phenomenon and reflection.

For example, as shown in fig. 24, 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 surfaces of the ribs. The surface treatment method may include chemical etching, physical grinding, or any other surface treatment method capable of increasing the surface roughness.

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

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

Forming the non-processing region NEA and the positions of the stepped portions E11 and E21 as described above may facilitate measurement of the concentricity of the lens by using a test equipment. For example, with the lens having the above-described shape, since the first step portion E11 and the second step 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.

The above-described examples enable the optical imaging system to be miniaturized and enable aberrations to be easily corrected.

While the disclosure includes specific examples, it will be apparent, upon an understanding of the present disclosure, that various changes in form and detail may be made to these examples without departing from the spirit and scope of the claims and their equivalents. The examples described in this application are to be considered in a descriptive sense only and not for purposes of limitation. The description of features or aspects in each example should be considered applicable to similar features or aspects in other examples. Suitable results may also be obtained if the described techniques are performed in a different order and/or if components in the described systems, architectures, devices, or circuits are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the present disclosure should be defined not by the detailed description but by the claims and their equivalents, and all modifications within the scope of the claims and their equivalents should be understood as being included in the present disclosure.

Claims

1. An optical imaging system, characterized in that the optical imaging system comprises:

a first lens having a positive refractive power;

a second lens having refractive power;

a third lens having refractive power;

a fourth lens having a refractive power and 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 refractive power and a concave object-side surface,

wherein the first lens to the eighth lens are arranged in order in numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging surface of the optical imaging system.

2. The optical imaging system of claim 1, wherein the second lens has a negative optical power.

3. The optical imaging system of claim 1, wherein an object side of the third lens is convex.

4. The optical imaging system of claim 1, wherein an object side of the fifth lens is concave.

5. The optical imaging system of claim 1, wherein an image side surface of the sixth lens is convex.

6. The optical imaging system of claim 1, wherein an object side of the seventh lens is concave.

7. The optical imaging system according to claim 1, wherein the optical imaging system satisfies 0.1< L1w/L8w <0.3, wherein 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.

8. The optical imaging system of claim 1, further comprising a spacer disposed between the seventh lens and the eighth lens,

wherein the optical imaging system satisfies 1.0< S7d/f <1.4, wherein S7d is an inner diameter of the cage, f is an overall focal length of the optical imaging system, and S7d and f are expressed in the same units of measure.

9. The optical imaging system of claim 1, wherein the optical imaging system satisfies 0.4< L1TD/L8TD <0.8, wherein 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 units of measure.

10. The optical imaging system according to claim 1, wherein the optical imaging system satisfies 0.4< L1234TDavg/L8TD <0.8, where L1234TDavg is an average of total outer diameters of the first to fourth lenses, L8TD is a total outer diameter of the eighth lens, and L1234TDavg and L8TD are expressed in the same measurement unit.

11. The optical imaging system according to claim 1, wherein the optical imaging system satisfies 0.5< L12345TDavg/L8TD <0.8, wherein L12345TDavg is an average of total outer diameters of the first to fifth lenses, L8TD is a total outer diameter of the eighth lens, and L12345TDavg and L8TD are expressed in the same measurement unit.

12. The optical imaging system according to claim 1, wherein the optical imaging system satisfies (V2+ V4)/2<20, where V2 is the abbe number of the second lens and V4 is the abbe number of the fourth lens.

13. The optical imaging system according to claim 1, wherein the optical imaging system satisfies 50< (V5+ V6+ V7+ V8)/4, where V5 is an abbe number of the fifth lens, V6 is an abbe number of the sixth lens, V7 is an abbe number of the seventh lens, and V8 is an abbe number of the eighth lens.

14. The optical imaging system of claim 1, wherein the optical imaging system satisfies 1.6< Nd2<1.8, where Nd2 is the refractive index of the second lens.

15. The optical imaging system of claim 1, wherein the optical imaging system satisfies 1.6< Nd4<1.8, wherein Nd4 is a refractive index of the fourth lens.

16. An optical imaging system, characterized in that the optical imaging system comprises:

a first lens having refractive power;

a second lens having refractive power;

a third lens having refractive power;

a fourth lens having refractive power;

a fifth lens having a positive refractive power and a convex image side surface;

a sixth lens having a positive refractive power and a convex image-side surface;

a seventh lens having refractive power; and

an eighth lens having a negative refractive power,

17. The optical imaging system of claim 16, wherein each of the first lens and the third lens has a positive optical power, and

the second lens has a negative refractive power.

18. The optical imaging system of claim 16, wherein each of the first through fourth lenses has a convex object side surface and a concave image side surface.

19. The optical imaging system of claim 16, wherein each of the fifth, seventh, and eighth lenses has a concave object-side surface,

the seventh lens element has a convex image-side surface, an

The eighth lens has a concave image-side surface.

20. The optical imaging system of claim 16, wherein the optical imaging system satisfies 1.0< TTL/f1<1.4, wherein TTL is a distance along the optical axis from an object side surface of the first lens to the imaging surface, f1 is a focal length of the first lens, and TTL and f1 are expressed in the same units of measure.