CN114859521A

CN114859521A - Optical imaging system

Info

Publication number: CN114859521A
Application number: CN202210666531.9A
Authority: CN
Inventors: 许宰赫; 金炳贤; 梁召渼
Original assignee: Samsung Electro Mechanics Co Ltd
Current assignee: Samsung Electro Mechanics Co Ltd
Priority date: 2021-10-06
Filing date: 2022-06-02
Publication date: 2022-08-05

Abstract

An optical imaging system is provided. The optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens that are arranged in this order from an object side to an imaging side. The first lens has a positive refractive power and the second lens has a negative refractive power. TTL >10.2mm, and TTL/(2 × IMG HT) ≦ 1.7, where TTL is a distance from an object side surface of the first lens to an imaging plane on an optical axis, and IMG HT is equal to half a diagonal length of the imaging plane.

Description

Optical imaging system

Cross Reference to Related Applications

This application claims the benefit of priority of korean patent application No. 10-2021-.

Technical Field

The following description relates to optical imaging systems.

Background

A portable terminal may include a camera including an optical imaging system in combination with a plurality of lenses to perform operations such as, but not limited to, video calls and image capture.

As operations performed by cameras included in portable terminals gradually increase, demand for high-resolution cameras for portable terminals increases.

Image sensors with high pixel counts (e.g., 1300 ten thousand to 1 million pixels, etc.) may be used in cameras incorporated in portable terminals to achieve improved image quality.

In addition, since the portable terminal may be implemented to have a small size, a camera provided in the portable terminal may also be implemented to have a reduced size, and thus, it may be desirable to develop an optical imaging system that can achieve high resolution while having a reduced size.

The above information is presented merely as background information to help gain an understanding of the present disclosure. No determination is made as to whether any of the above can be used as prior art with respect to the present disclosure, nor is an assertion made.

Disclosure of Invention

This summary 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 a general aspect, an optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged in this order from an object side to an imaging side, wherein: the first lens has a positive refractive power and the second lens has a negative refractive power; and TTL >10.2mm, and TTL/(2 × IMG HT) ≦ 1.7, where TTL is a distance from an object side surface of the first lens to the imaging plane on the optical axis, and IMG HT is equal to half a diagonal length of the imaging plane.

In the optical imaging system, IMG HT ≧ 4.5mm, where f is the total focal length of the optical imaging system.

n2+ n3>3.20, where n2 is the refractive index of the second lens and n3 is the refractive index of the third lens.

I f/f1+ f/f2 i <1.2, where f is the total focal length of the optical imaging system, f1 is the focal length of the first lens, and f2 is the focal length of the second lens.

BFL/f <0.4, where f is the total focal length of the optical imaging system and BFL is the distance from the image side surface of the fifth lens to the imaging surface on the optical axis.

TTL/f is more than or equal to 0.80 and less than or equal to 1.05, wherein f is the total focal length of the optical imaging system.

0 ≦ D1/f ≦ 0.05, where f is the total focal length of the optical imaging system, and D1 is the distance between the image-side surface of the first lens and the object-side surface of the second lens on the optical axis.

R1/f ≦ 0.35, where f is the total focal length of the optical imaging system, and R1 is the radius of curvature of the object-side surface of the first lens.

The third lens may have a positive refractive power, the fourth lens may have a negative refractive power, and the fifth lens may have a negative refractive power.

The third lens may have a positive refractive power, the fourth lens may have a positive refractive power, and the fifth lens may have a negative refractive power.

The third lens may have a negative refractive power, the fourth lens may have a positive refractive power, and the fifth lens may have a negative refractive power.

The optical imaging system may further include a sixth lens disposed between the fifth lens and the imaging surface, wherein: the third lens has a positive refractive power, the fourth lens has a positive refractive power, the fifth lens has a negative refractive power, and the sixth lens has a negative refractive power.

The optical imaging system may further include a sixth lens disposed between the fifth lens and the imaging surface, wherein: the third lens has a positive refractive power, the fourth lens has a positive refractive power, the fifth lens has a positive refractive power, and the sixth lens has a negative refractive power.

At least one of the second lens and the third lens may have a refractive index greater than 1.64.

An absolute value of a focal length of each of the first lens and the second lens may be smaller than an absolute value of a focal length of each of the third lens, the fourth lens, and the fifth lens.

Other features and aspects will become apparent from the following detailed description, the appended claims, the drawings, and the following drawings.

Drawings

Fig. 1 is a diagram illustrating an exemplary optical imaging system according to a first exemplary embodiment.

Fig. 2 is a graph illustrating aberration characteristics of the exemplary optical imaging system shown in fig. 1.

Fig. 3 is a diagram illustrating an exemplary optical imaging system according to a second exemplary embodiment.

Fig. 4 is a graph illustrating aberration characteristics of the exemplary optical imaging system shown in fig. 3.

Fig. 5 is a diagram illustrating an exemplary optical imaging system according to a third exemplary embodiment.

Fig. 6 is a graph illustrating aberration characteristics of the exemplary optical imaging system shown in fig. 5.

Fig. 7 is a diagram illustrating an exemplary optical imaging system according to a fourth exemplary embodiment.

Fig. 8 is a graph illustrating aberration characteristics of the exemplary optical imaging system shown in fig. 7.

Fig. 9 is a diagram illustrating an exemplary optical imaging system according to a fifth exemplary embodiment.

Fig. 10 is a graph illustrating aberration characteristics of the exemplary optical imaging system shown in fig. 9.

Fig. 11 is a diagram illustrating an exemplary optical imaging system according to a sixth exemplary embodiment.

Fig. 12 is a graph illustrating aberration characteristics of the exemplary optical imaging system shown in fig. 11.

Fig. 13 is a diagram illustrating an exemplary optical imaging system according to a seventh exemplary embodiment.

Fig. 14 is a graph illustrating aberration characteristics of the exemplary optical imaging system shown in fig. 13.

Fig. 15 is a diagram illustrating an example of including a reflective member in the exemplary optical imaging system illustrated in fig. 1.

Fig. 16 is a plan view illustrating a non-circular lens of an exemplary optical imaging system according to an exemplary embodiment.

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, apparatuses, and/or systems described herein. Various changes, modifications, and equivalents of the methods, devices, and/or systems described herein will, however, be apparent to those skilled in the art in view of the disclosure of this application. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, except as operations that must occur in a particular order, but may be changed as will be apparent after understanding the disclosure of the present application. Furthermore, the description of features known after understanding the disclosure of the present application may be omitted for clarity and conciseness, but it should be noted that the omission of features and their description is not an admission that they are common general knowledge.

The features described herein may be embodied in different forms and should not be construed as limited to the examples described herein. 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 that will be apparent after understanding the disclosure of the present application.

It should be noted that the use of the phrase "may" in this document with respect to an embodiment or example (e.g., with respect to what an embodiment or example may include or implement) means that there is at least one embodiment or example in which such feature is included or implemented, and all embodiments and examples are not limited thereto.

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 are no other elements intervening between the element and the other element.

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

Spatially relative terms such as "above … …," "upper," "below … …," and "lower" 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 term "above … …" encompasses both orientations of "above and" below. The device may also be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative terms used herein should be interpreted accordingly.

The terminology used herein 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 "comprising," "including," and "having" specify the presence of stated features, integers, operations, elements, components, 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.

Variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, may be expected. Thus, examples described herein are not limited to the specific shapes shown in the drawings, but include changes in shape that occur during manufacturing.

The features of the examples described herein may be combined in various ways that will be apparent after having obtained an understanding of the disclosure of the present application. Moreover, while the examples described herein have a variety of configurations, other configurations are possible as will be apparent after an understanding of the disclosure of the present application.

Hereinafter, examples of the present disclosure will be described as follows with reference to the drawings.

One or more examples provide an optical imaging system that can achieve high resolution.

In the lens drawings, the thickness, size, and shape of the lens are exaggerated, and in particular, the shape of a spherical surface or an aspherical surface presented in the lens drawings is only an example, but not limited thereto.

An optical imaging system according to an exemplary embodiment may include a plurality of lenses disposed along an optical axis. The plurality of lenses may be spaced apart from each other by a predetermined distance along the optical axis.

As an example, the optical imaging system comprises five or six lenses.

Among the lenses included in the optical imaging system, the foremost lens may refer to a lens closest to the object side (or the reflection member), and the rearmost lens may refer to a lens closest to the imaging plane (or the image sensor).

As an example, in an embodiment in which the optical imaging system includes five lenses, the first lens may refer to a lens closest to the object side (or the reflection member), and the fifth lens may refer to a lens closest to the imaging plane (or the image sensor).

In an embodiment where the optical imaging system includes six lenses, the first lens may refer to a lens closest to the object side (or the reflecting member), and the sixth lens may refer to a lens closest to the imaging plane (or the image sensor). In addition, in the exemplary embodiment, the radius of curvature, thickness, distance, and focal length of the lens are expressed in millimeters (mm), and the field of view (FOV) is expressed in degrees.

In the description of the shape of each lens, a configuration in which one face is convex means that the paraxial region portion or paraxial region of the face is convex, a configuration in which one face is concave means that the paraxial region portion or paraxial region of the face is concave, and a configuration in which one face is flat means that the paraxial region portion or paraxial region of the face is flat. Thus, when one face of the lens is described as convex, the edge portion of the lens may be concave. Similarly, when one face of the lens is described as concave, the edge portion of the lens may be convex. In addition, when one face of the lens is described as flat, the edge portion of the lens may be convex or concave.

The paraxial region can refer to a significantly narrow region adjacent the optical axis.

The imaging plane may refer to a virtual plane on which an in-focus image is formed by the optical imaging system. Alternatively, the imaging plane may refer to one surface of the image sensor on which light is received.

The optical imaging system in an exemplary embodiment may include six lenses.

In an example, the optical imaging system in the exemplary embodiment may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged in this order from the object side to the imaging side. The first to sixth lenses may be spaced apart from each other by a predetermined distance along the optical axis.

The optical imaging system in another exemplary embodiment may include five lenses.

For example, the optical imaging system in the exemplary embodiment may include a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged in this order from the object side to the imaging side. The first to fifth lenses may be spaced apart from each other by a predetermined distance along the optical axis.

However, the optical imaging system in the exemplary embodiment may include not only five lenses or six lenses but also further include other components as necessary.

For example, referring to fig. 15, the optical imaging system may further include a reflective member having a reflective surface that changes a path of light. The reflective member may be configured to change the optical member by 90 degrees (as an example only). As an example, the reflecting member may be implemented as a mirror or a prism.

The reflective member may be disposed in front of the plurality of lenses. As an example, the reflective member may be disposed in front of the first lens (e.g., closer to the object side than the first lens). Accordingly, in one or more examples, the lens disposed closest to the object side may be the lens disposed closest to the reflective member.

The optical imaging system may further include an image sensor that converts an incident image of the subject into an electrical signal.

The optical imaging system may further include an infrared cut filter (hereinafter referred to as "filter") that blocks infrared rays. The filter may be disposed between the lens (fifth lens or sixth lens) disposed closest to the imaging surface and the imaging surface.

The optical imaging system may further include a diaphragm that adjusts the amount of light.

All lenses included in the optical imaging system in the exemplary embodiment may be formed of a plastic material.

Further, each lens may be formed of a plastic material having optical characteristics different from those of adjacent lenses.

Referring to fig. 16, at least some of the lenses of the optical imaging system may have a non-circular planar shape. In an example, the frontmost lens and the rearmost lens may have non-circular planar shapes. The other lenses may have a non-circular planar shape or a circular planar shape.

The non-circular lens may have four side surfaces, and two side surfaces are formed to be opposite to each other. Further, the side surfaces opposite to each other may have a corresponding shape.

In an example, the first lens may have a first side surface, a second side surface, a third side surface, and a fourth side surface. The first side surface and the second side surface are disposed opposite to each other with respect to the optical axis, and the third side surface and the fourth side surface are disposed opposite to each other with respect to the optical axis. Each of the third and fourth side surfaces may connect the first and second side surfaces.

The first and second side surfaces of the first lens may have an arc shape when viewed in the optical axis direction, and the third and fourth side surfaces may have a substantially linear shape.

Each of the third and fourth side surfaces may connect the first and second side surfaces. Further, the third side surface and the fourth side surface may be symmetrical with respect to the optical axis and may be formed to be parallel to each other.

The non-circular lens may have a first axis and a second axis that intersect the optical axis. In an example, the first axis may be an axis connecting the first side surface and the second side surface while passing through the optical axis, and the second axis may be an axis connecting the third side surface and the fourth side surface while passing through the optical axis. The first and second axes may be perpendicular to each other, and the length of the first axis may be greater than the length of the second axis.

In an example, the first lens may have two axes intersecting the optical axis and perpendicular to each other, and a length of one of the two axes may be greater than a length of the other of the two axes.

Referring to fig. 16, all lenses of the optical imaging system may include an optical portion 10 and a flange portion 30.

The optical portion 10 may be a portion in which the optical properties of the lens are exhibited. In an example, light reflected from an object may be refracted while passing through the optical portion 10.

The optical portion 10 may have optical power and may have an aspherical shape.

In addition, the optical portion 10 may have an object side surface (a surface facing the object side) and an image side surface (a surface facing the image side) (the object side surface is illustrated in fig. 16).

The flange portion 30 may be a portion that secures the lens to another component (e.g., a lens barrel or another lens).

The flange portion 30 may extend from the periphery of at least a portion of the optical portion 10, and may be formed to be integrated with the optical portion 10.

In the non-circular lens, the optical portion 10 and the flange portion 30 may be formed in a non-circular shape. In an example, the optical portion 10 and the flange portion 30 may be non-circular when viewed in the optical axis direction (see fig. 16). Alternatively, the optical portion 10 may be formed to be circular, and the flange portion 30 may be formed to be non-circular.

The optical portion 10 may include a first edge 11, a second edge 12, a third edge 13, and a fourth edge 14. The first edge 11 and the second edge 12 may be disposed opposite to each other, and the third edge 13 and the fourth edge 14 may be disposed opposite to each other.

Each of the third edge 13 and the fourth edge 14 may connect the first edge 11 and the second edge 12.

The first edge 11 and the second edge 12 may be disposed opposite to each other with respect to the optical axis, and the third edge 13 and the fourth edge 14 may be disposed opposite to each other with respect to the optical axis.

The first edge 11 and the second edge 12 may have an arc shape, and the third edge 13 and the fourth edge 14 may have a substantially linear shape, when viewed in the optical axis direction. The third edge 13 and the fourth edge 14 may be formed to be symmetrical with respect to the optical axis (Z axis) and parallel to each other.

The shortest distance between the first edge 11 and the second edge 12 may be greater than the shortest distance between the third edge 13 and the fourth edge 14.

The optical portion 10 may have a major axis "a" and a minor axis "b". In an example, when viewed from the optical axis direction, a line segment connecting the third edge 13 and the fourth edge 14 with the shortest distance while passing through the optical axis may be a short axis "b", and a line segment connecting the first edge 11 and the second edge 12 while passing through the optical axis and perpendicular to the short axis "b" may be a long axis "a".

In this example, half of the major axis "a" may be the maximum effective radius, and half of the minor axis "b" may be the minimum effective radius.

Assuming that the lens shown in fig. 16 is the front-most lens (e.g., the first lens), the maximum effective radius of the object-side surface of the front-most lens is reference numeral L1S1el of fig. 16, and the minimum effective radius of the object-side surface of the front-most lens is reference numeral L1S1es of fig. 16.

The flange portion 30 may include a first flange portion 31 and a second flange portion 32. The first flange portion 31 may extend from the first edge 11 of the optical portion 10, and the second flange portion 32 may extend from the second edge 12 of the optical portion 10.

The first edge 11 of the optical portion 10 may refer to a portion adjacent to the first flange portion 31, and the second edge 12 of the optical portion 10 may refer to a portion adjacent to the second flange portion 32.

The third edge 13 of the optical part 10 may refer to one side surface of the optical part 10 where the flange part 30 is not formed, and the fourth edge 14 of the optical part 10 may refer to the other side surface or the opposite side surface of the optical part 10 where the flange part 30 is not formed.

An effective radius of each of the first lens and the fifth lens may be larger than an effective radius of each of the other lenses.

The term "effective radius" refers to the radius of one face (object side face and image side face) of each lens through which light actually passes. In an example, the term "effective radius" may refer to the radius of the optical portion of each lens.

The non-circular lens may have a maximum effective radius (half of a straight line connecting the first edge 11 and the second edge 12 while passing through the optical axis) and a minimum effective radius (half of a straight line connecting the third edge 13 and the fourth edge 14 while passing through the optical axis).

In one or more examples, the term "effective radius" may refer to the maximum effective radius, unless otherwise specified.

Each of the plurality of lenses may have at least one aspheric surface.

That is, at least one of the first face and the second face of each lens may be an aspherical surface. The aspherical surface of each lens is represented as follows:

equation 1:

in equation 1, c is the curvature (inverse of the radius of curvature) of the lens, K is a conic constant, and Y is the distance from one point on the aspherical surface of the lens to the optical axis in the direction perpendicular to the optical axis. In addition, the constants a to J are aspherical coefficients. Z is a distance from a point on the aspherical surface of the lens to the vertex of the aspherical surface in the optical axis direction.

The optical imaging system including the first lens to the sixth lens may have a positive refractive power, a negative refractive power, a positive refractive power, a negative refractive power, and a negative refractive power, respectively, in this order from the object side to the imaging side, or may have a positive refractive power, a negative refractive power, a positive refractive power, and a negative refractive power, respectively, in this order from the object side to the imaging side.

The optical imaging system including the first lens to the fifth lens may have a positive refractive power, a negative refractive power, and a negative refractive power, respectively, in order from the object side to the imaging side, or may have a positive refractive power, a negative refractive power, a positive refractive power, and a negative refractive power, respectively, in order from the object side to the imaging side, or may have a positive refractive power, a negative refractive power, a positive refractive power, and a negative refractive power, respectively, in order from the object side to the imaging side.

The optical imaging system in the exemplary embodiment may satisfy at least one of the following conditional expressions:

conditional expression 1: TTL >10.2mm

Conditional expression 2: 10.2mm < TTL <16mm

Conditional expression 3: TTL/(2x IMG HT) is less than or equal to 1.7

Conditional expression 4: 1.2 TTL/(2x IMG HT) is less than or equal to 1.7

Conditional expression 5: 1.5< f/IMG HT <3.5

Conditional expression 6: IMG HT is more than or equal to 4.5mm

Conditional expression 7: n2+ n3>3.20

Conditional expression 8: i f/f1+ f/f 2I <1.2 |

Conditional expression 9: d1/f is more than or equal to 0 and less than or equal to 0.05

Conditional expression 10: TTL/f is more than or equal to 0.80 and less than or equal to 1.05

Conditional expression 11: r1/f is less than or equal to 0.35

Conditional expression 12: BFL/f <0.4

In the conditional expressions, f is the total focal length of the optical imaging system, f1 is the focal length of the first lens, and f2 is the focal length of the second lens.

In the conditional expression, n2 is the refractive index of the second lens, and n3 is the refractive index of the third lens.

In the conditional expression, TTL is a distance from the object-side surface of the foremost lens or the first lens to the imaging surface on the optical axis, and BFL is a distance from the image-side surface of the rearmost lens to the imaging surface on the optical axis.

In the conditional expressions, D1 is a distance between an image-side surface of the first lens and an object-side surface of the second lens on the optical axis, R1 is a radius of curvature of the object-side surface of the first lens, and IMG HT is equal to half a diagonal length of the imaging plane.

The optical imaging system in the exemplary embodiment may have the characteristics of a telephoto lens having a relatively narrow field of view and a relatively long focal length.

In addition, the optical imaging system in the exemplary embodiment may be configured to have a relatively large diagonal length of the imaging plane. In an example, the effective imaging area of the image sensor may be wide (e.g., a high pixel image sensor).

Accordingly, when the captured image is cropped, images of various magnifications can be captured without degrading image quality.

The absolute value of the focal length of each of the first and second lenses may be smaller than the absolute value of the focal length of each of the other lenses.

An optical imaging system according to a first exemplary embodiment will be described with reference to fig. 1 and 2.

The optical imaging system 100 in the first exemplary embodiment may include an optical system including the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, and the sixth lens 160, and may further include an optical filter 170 and an image sensor IS.

The optical imaging system 100 in the first exemplary embodiment can form an in-focus image on the imaging plane 180 of the image sensor IS. The imaging plane 180 may refer to a surface on which an in-focus image is formed by the optical imaging system 100. In an example, the imaging plane 180 may refer to one surface of the image sensor IS on which light IS received.

Although not shown in fig. 1, the optical imaging system 100 may further include a reflective member R (see fig. 15) disposed in front of the first lens 110 and having a reflective surface that changes a path of light. In the first exemplary embodiment, the reflecting member R may be a prism, but may also be implemented as a mirror.

Lens characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index, abbe number and focal length) of each lens are listed in table 1 below.

TABLE 1

The total focal length f of the optical imaging system in the first exemplary embodiment is 15mm, and IMG HT is 5.128 mm.

In the first exemplary embodiment, the first lens 110 may have a positive refractive power, and the first surface of the first lens 110 may be convex, and the second surface of the first lens 110 may also be convex.

The second lens 120 may have a negative refractive power, a first surface of the second lens 120 may be convex, and a second surface of the second lens 120 may be concave.

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

The fourth lens 140 may have a positive refractive power, a first surface of the fourth lens 140 may be convex, and a second surface of the fourth lens 140 may be concave.

The fifth lens 150 may have a negative refractive power, a first surface of the fifth lens 150 may be convex, and a second surface of the fifth lens 150 may be concave.

The sixth lens 160 may have a negative refractive power, a first surface of the sixth lens 160 may be convex in a paraxial region, and a second surface of the sixth lens 160 may be concave in the paraxial region.

In addition, the sixth lens 160 may have at least one inflection point formed on at least one of the first and second faces. In an example, the second face of the sixth lens 160 may be concave in the paraxial region and convex in a portion other than the paraxial region.

Each of the surfaces of the first through sixth lenses 110 through 160 may have aspherical coefficients listed in the following table 2. In an example, the object side and the image side of the first through sixth lenses 110 through 160 may be aspheric.

TABLE 2

The optical imaging system 100 of the above configuration may have the aberration characteristics shown in fig. 2.

An optical imaging system according to a second exemplary embodiment will be described with reference to fig. 3 and 4.

The optical imaging system 200 in the second exemplary embodiment may include an optical system including a first lens 210, a second lens 220, a third lens 230, a fourth lens 240, a fifth lens 250, and a sixth lens 260, and may further include an optical filter 270 and an image sensor IS.

The optical imaging system 200 in the second exemplary embodiment can form an in-focus image on the imaging plane 280. The imaging plane 280 may refer to a surface of the image sensor IS on which an in-focus image IS formed by the optical imaging system 200. In an example, the imaging plane 280 may refer to one surface of the image sensor IS on which light IS received.

Although not shown in fig. 3, the optical imaging system 200 may further include a reflective member R (see fig. 15) disposed in front of the first lens 210 and having a reflective surface that changes a path of light. In the second exemplary embodiment, the reflecting member R may be a prism, but may also be implemented as a mirror.

Lens characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index, abbe number and focal length) of each lens are listed in table 3 below.

TABLE 3

Noodle numbering	Marking	Radius of curvature	Thickness or distance	Refractive index	Abbe number	Focal length
							S1	First lens	4.9489607	2.000	1.537	55.7	9.14375
S2		-556.8638	0.050
							S3	Second lens	35.489609	0.650	1.646	23.5	-8.68276
S4		4.8058549	1.500
							S5	Third lens	4.0957987	0.722	1.679	19.2	44.0122
S6		4.4080644	0.300
							S7	Fourth lens	4.9340121	0.614	1.537	55.7	29.4635
S8		6.8575524	0.500
							S9	Fifth lens element	6.794379	0.775	1.646	23.5	144.143
S10		7.0017622	3.797
							S11	Sixth lens element	5.0156608	0.800	1.537	55.7	-54.7209
S12		4.0457338	3.000
							S13	Light filter	Infinity(s)	0.210	1.519	64.2
S14		Infinity(s)	0.813
							S15	Image plane	Infinity(s)

The total focal length f of the optical imaging system in the second exemplary embodiment is 15mm, and IMG HT is 5.4 mm.

In the second exemplary embodiment, the first lens 210 may have a positive refractive power, and the first surface of the first lens 210 and the second surface of the first lens 210 may also be convex.

The second lens 220 may have a negative refractive power, a first surface of the second lens 220 may be convex, and a second surface of the second lens 220 may be concave.

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

Fourth lens 240 may have a positive refractive power, a first surface of fourth lens 240 may be convex, and a second surface of fourth lens 240 may be concave.

The fifth lens 250 may have a positive refractive power, a first surface of the fifth lens 250 may be convex, and a second surface of the fifth lens 250 may be concave.

Sixth lens 260 may have a negative refractive power, a first surface of sixth lens 260 may be convex in a paraxial region, and a second surface of sixth lens 260 may be concave in the paraxial region.

In addition, the sixth lens 260 may have at least one inflection point formed on at least one of the first and second faces. In an example, the first face of the sixth lens 260 may be convex in the paraxial region and concave in a portion or region other than the paraxial region. In addition, the second face of the sixth lens 260 may be concave in the paraxial region and convex in a portion or region other than the paraxial region.

Each surface of the first to sixth lenses 210 to 260 may have an aspherical coefficient as shown in table 4 below. In an example, both the object side and the image side of the first through sixth lenses 210 through 260 may be aspheric.

TABLE 4

S1

S2

S3

S4

S5

S6

Conic constant (K)

-0.67258

-99.00000

97.49800

0.00000

-0.07552

Coefficient of 4 th order (A)

1.5128E-05

2.2191E-04

-6.5288E-05

-1.1672E-03

-5.5861E-04

-8.1068E-04

Coefficient of order 6 (B)

-1.5868E-05

-7.7041E-06

1.6242E-05

-5.8934E-05

-4.6455E-05

-2.2661E-05

Coefficient of order 8 (C)

-1.0719E-06

-9.8215E-07

-9.0232E-07

2.7014E-07

-1.8291E-08

-1.9193E-06

Coefficient of order 10 (D)

-4.0847E-08

-9.5109E-08

-1.2800E-07

1.9644E-07

3.5870E-07

2.5331E-08

Coefficient of order 12 (E)

-1.5147E-09

-4.2905E-09

-1.3036E-08

-1.2270E-08

2.9772E-08

1.9633E-07

Coefficient of order 14 (F)

-2.8803E-11

-1.9582E-10

-8.6113E-10

-4.2051E-09

6.5213E-09

4.5778E-08

Coefficient of order 16 (G)

4.5059E-12

-2.7803E-11

-3.7076E-11

-7.5074E-10

5.2618E-10

4.1697E-09

Coefficient of 18 th order (H)

-9.5468E-13

1.8389E-12

3.6135E-13

-5.5324E-11

2.0863E-11

-1.7698E-10

Coefficient of order 20 (J)

2.5397E-14

1.6251E-13

3.2132E-13

1.1687E-11

-1.7045E-11

-2.1568E-10

S7

S8

S9

S10

S11

S12

Conic constant (K)

0.26498

-0.92638

-2.57360

1.02810

-8.37140

-5.03820

Coefficient of 4 th order (A)

-9.9991E-04

-3.6957E-04

-1.9038E-03

-1.3893E-03

-4.0396E-03

-4.6693E-03

Coefficient of order 6 (B)

8.2990E-05

7.6680E-05

-6.8259E-05

2.0829E-04

-1.1804E-04

1.7996E-05

Coefficient of order 8 (C)

1.3755E-05

3.2877E-05

-3.0848E-06

-3.7592E-05

1.1598E-05

7.6129E-06

Coefficient of order 10 (D)

4.8742E-06

6.5958E-06

-4.1405E-06

-6.7933E-06

4.8391E-07

1.3341E-08

Coefficient of order 12 (E)

5.8840E-07

4.2469E-07

-6.8348E-07

2.3833E-07

-1.5465E-08

-2.4877E-08

Coefficient of order 14 (F)

6.6712E-08

5.1166E-08

-3.2432E-08

6.8499E-09

-3.7533E-09

-9.9716E-10

Coefficient of order 16 (G)

6.4327E-09

5.9823E-09

4.1342E-09

-4.1045E-09

1.3933E-14

1.9553E-10

Coefficient of 18 th order (H)

2.0057E-10

4.6032E-11

1.9997E-09

2.2852E-09

-3.0871E-12

-1.1070E-11

Coefficient of order 20 (J)

-3.2966E-10

-1.1904E-10

-1.4404E-10

-1.1245E-10

8.2208E-13

2.8425E-13

In addition, the optical imaging system 200 of the above configuration may have the aberration characteristics shown in fig. 4.

An optical imaging system 300 according to a third exemplary embodiment will be described with reference to fig. 5 and 6.

The optical imaging system 300 in the third exemplary embodiment may include an optical system including a first lens 310, a second lens 320, a third lens 330, a fourth lens 340, and a fifth lens 350, and may further include an optical filter 370 and an image sensor IS.

The optical imaging system 300 in the third exemplary embodiment can form an in-focus image on the imaging plane 380 of the image sensor IS. The imaging plane 380 may refer to a surface on which an in-focus image is formed by the optical imaging system 300. In an example, the imaging plane 380 may refer to one surface of the image sensor IS on which light IS received.

Although not shown in fig. 5, the optical imaging system 300 may further include a reflective member R (see fig. 15) disposed in front of the first lens 310 and having a reflective surface that changes a path of light. In the third exemplary embodiment, the reflecting member R may be a prism, but may also be implemented as a mirror.

Lens characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index, abbe number and focal length) of each lens are listed in table 5 below.

TABLE 5

Noodle numbering	Marking	Radius of curvature	Thickness or distance	Refractive index	Abbe number	Focal length
							S1	First lens	4.2994663	2.000	1.537	55.7	6.523
S2		-15.76502	0.050
							S3	Second lens	-16.46547	0.500	1.646	23.5	-5.98498
S4		5.0925379	0.957
							S5	Third lens	4.2766847	1.155	1.679	19.2	8.981
S6		13.358993	0.050
							S7	Fourth lens	5.7826016	0.400	1.537	55.7	-18.6452
S8		3.8549855	3.389
							S9	Fifth lens element	7.9053798	0.500	1.646	23.5	-31.2964
S10		5.2564001	3.000
							S11	Light filter	Infinity(s)	0.210	1.519	64.2
S12		Infinity(s)	1.887
							S13	Image plane	Infinity(s)

The total focal length f of the optical imaging system 300 in the third exemplary embodiment is 15mm, and the IMG HT is 5.4 mm.

In the third exemplary embodiment, the first lens 310 may have a positive refractive power, and the first surface of the first lens 310 may be convex, and the second surface of the first lens 310 may be convex.

The second lens 320 may have a negative refractive power, and a first surface of the second lens 320 may be concave and a second surface of the second lens 320 may be concave.

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

The fourth lens 340 may have a negative refractive power, a first surface of the fourth lens 340 may be convex, and a second surface of the fourth lens 340 may be concave.

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

In addition, the fifth lens 350 may have at least one inflection point formed on at least one of the first and second faces. In an example, the first face of the fifth lens 350 may be convex in the paraxial region and concave in a portion or region other than the paraxial region. The second face of the fifth lens 350 may be concave in the paraxial region and convex in a portion or region other than the paraxial region.

Each surface of the first through fifth lenses 310 through 350 may have an aspheric coefficient as shown in table 6 below. In an example, both the object side and the image side of the first through fifth lenses 310 through 350 may be aspheric.

TABLE 6

The optical imaging system 300 of the above configuration may have the aberration characteristics shown in fig. 6.

An optical imaging system 400 according to a fourth exemplary embodiment will be described with reference to fig. 7 and 8.

The optical imaging system 400 in the fourth exemplary embodiment may include an optical system including a first lens 410, a second lens 420, a third lens 430, a fourth lens 440, and a fifth lens 450, and may further include an optical filter 470 and an image sensor IS.

The optical imaging system 400 in the fourth exemplary embodiment can form an in-focus image on the imaging plane 480 of the image sensor IS. The imaging plane 480 may refer to a surface on which an in-focus image is formed by the optical imaging system 400. As an example, the imaging plane 480 may refer to one surface of the image sensor IS on which light IS received.

Although not shown in fig. 7, the optical imaging system 400 may further include a reflective member R (see fig. 15) disposed in front of the first lens 410 and having a reflective surface that changes a path of light. In the fourth exemplary embodiment, the reflecting member R may be a prism, but may also be implemented as a mirror.

Lens characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index, abbe number and focal length) of each lens are listed in table 7 below.

TABLE 7

The optical imaging system 400 in the fourth exemplary embodiment has an overall focal length f of 14.9997mm and an IMG HT of 5.4 mm.

In the fourth exemplary embodiment, the first lens 410 may have a positive refractive power, and the first surface of the first lens 410 may be convex, and the second surface of the first lens 410 may be convex.

The second lens 420 may have a negative refractive power, and a first surface of the second lens 420 may be concave and a second surface of the second lens 420 may be concave.

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

The fourth lens 440 may have a negative refractive power, a first surface of the fourth lens 440 may be convex, and a second surface of the fourth lens 440 may be concave.

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

In addition, the fifth lens 450 may have at least one inflection point formed on at least one of the first and second faces. In an example, the first face of the fifth lens 450 may be convex in the paraxial region and concave in a portion or region other than the paraxial region. The second face of the fifth lens 450 may be concave in the paraxial region and convex in a portion or region other than the paraxial region.

Each surface of the first to fifth lenses 410 to 450 may have an aspherical coefficient as shown in table 8 below. In an example, both the object side and the image side of the first through fifth lenses 410 through 450 may be aspheric.

TABLE 8

In addition, the optical imaging system 400 of the above configuration may have aberration characteristics shown in fig. 8.

An optical imaging system 500 according to a fifth exemplary embodiment will be described with reference to fig. 9 and 10.

The optical imaging system 500 in the fifth exemplary embodiment may include an optical system including a first lens 510, a second lens 520, a third lens 530, a fourth lens 540, and a fifth lens 550, and may further include an optical filter 570 and an image sensor IS.

The optical imaging system 500 in the fifth exemplary embodiment can form an in-focus image on the imaging plane 580 of the image sensor IS. Imaging plane 580 may refer to a surface on which an in-focus image is formed by optical imaging system 500. In an example, the imaging plane 580 may refer to one surface of the image sensor IS on which light IS received.

Although not shown in fig. 9, the optical imaging system 500 may further include a reflective member R (see fig. 15) disposed in front of the first lens 510 and having a reflective surface that changes a path of light. In the fifth exemplary embodiment, the reflecting member R may be a prism, but may also be implemented as a mirror.

Lens characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index, abbe number and focal length) of each lens are listed in table 9.

TABLE 9

Noodle numbering	Marking	Radius of curvature	Thickness or distance	Refractive index	Abbe number	Focal length
							S1	First lens	4.40444	1.954	1.537	55.7	6.880
S2		-19.2806	0.120
							S3	Second lens	-17.4567	0.666	1.644	23.5	-6.91172
S4		6.06424	1.000
							S5	Third lens	5.08995	0.863	1.656	21.5	17.847
S6		8.40284	0.374
							S7	Fourth lens	7.00548	0.554	1.667	20.4	130.743
S8		7.37695	2.800
							S9	Fifth lens element	14.4676	0.676	1.537	55.7	-19.9373
S10		6.05004	3.000
							S11	Light filter	Infinity(s)	0.210	1.518	64.2
S12		Infinity(s)	1.883
							S13	Image plane	Infinity(s)

The optical imaging system 500 according to the fifth exemplary embodiment has an overall focal length f of 15mm and an IMG HT of 5.128 mm.

In the fifth exemplary embodiment, the first lens 510 may have a positive refractive power, and the first surface of the first lens 510 may be convex, and the second surface of the first lens 510 may be convex.

Second lens 520 may have a negative refractive power, and a first surface of second lens 520 may be concave and a second surface of second lens 520 may be concave.

The third lens 530 may have a positive refractive power, a first surface of the third lens 530 may be convex, and a second surface of the third lens 530 may be concave.

The fourth lens 540 may have a positive refractive power, a first surface of the fourth lens 540 may be convex, and a second surface of the fourth lens 540 may be concave.

The fifth lens 550 may have a negative refractive power, a first surface of the fifth lens 550 may be convex in a paraxial region, and a second surface of the fifth lens 550 may be concave in the paraxial region.

In addition, the fifth lens 550 may have at least one inflection point formed on at least one of the first and second faces. In an example, the first face of the fifth lens 550 may be convex in the paraxial region and concave in a portion or region other than the paraxial region. The second face of the fifth lens 550 may be concave in the paraxial region and convex in a portion or region other than the paraxial region.

Each surface of the first through fifth lenses 510 through 550 may have an aspheric coefficient as shown in table 10 below. In an example, both the object side and the image side of the first through fifth lenses 510 through 550 may be aspheric.

Watch 10

	S1	S2	S3	S4	S5
						Conic constant (K)	-0.67151	-2.06050	-67.39700	0.51600	0.48287
Coefficient of 4 th order (A)	-9.7544E-04	8.9298E-03	5.3855E-04	9.6592E-04	1.3533E-02
						Coefficient of order 6 (B)	3.7070E-03	-2.8714E-02	-2.2026E-02	-2.3244E-02	-3.6408E-02
Coefficient of order 8 (C)	-4.9650E-03	3.9580E-02	3.3095E-02	3.9136E-02	5.8110E-02
						Coefficient of order 10 (D)	4.1990E-03	-2.8768E-02	-2.4019E-02	-4.1540E-02	-6.7755E-02
Coefficient of order 12 (E)	-2.3418E-03	1.2652E-02	9.9311E-03	3.0969E-02	5.6345E-02
						Coefficient of order 14 (F)	8.9903E-04	-3.5434E-03	-2.2711E-03	-1.6822E-02	-3.3560E-02
Coefficient of order 16 (G)	-2.4448E-04	6.2316E-04	1.5889E-04	6.7901E-03	1.4514E-02
						Coefficient of 18 th order (H)	4.7772E-05	-5.9034E-05	6.6690E-05	-2.0467E-03	-4.5935E-03
Coefficient of order 20 (J)	-6.7196E-06	-1.1844E-07	-2.4662E-05	4.5742E-04	1.0621E-03
							S6	S7	S8	S9	S10
Conic constant (K)	-1.25120	1.48320	1.75320	-95.98000	-54.35500
						Coefficient of order 4 (A)	1.8194E-02	4.6046E-02	3.1108E-02	-2.1824E-02	3.0220E-03
Coefficient of order 6 (B)	-3.4014E-02	-2.0546E-01	-1.7731E-01	-6.6542E-03	-1.8476E-02
						Coefficient of order 8 (C)	3.1043E-02	5.2291E-01	5.7733E-01	1.5928E-02	1.7662E-02
Coefficient of order 10 (D)	-1.6899E-02	-9.0013E-01	-1.2497E+00	-1.8903E-02	-1.3015E-02
						Coefficient of order 12 (E)	2.3405E-03	1.0763E+00	1.8722E+00	1.4688E-02	7.2515E-03
Coefficient of order 14 (F)	4.7088E-03	-9.1427E-01	-1.9899E+00	-7.7684E-03	-2.9614E-03
						Coefficient of order 16 (G)	-4.6141E-03	5.6129E-01	1.5263E+00	2.8613E-03	8.7898E-04
Coefficient of 18 th order (H)	2.2951E-03	-2.5123E-01	-8.5201E-01	-7.4334E-04	-1.8951E-04
						Coefficient of order 20 (J)	-7.3358E-04	8.1937E-02	3.4585E-01	1.3645E-04	2.9590E-05

In addition, the optical imaging system 500 of the above configuration may have aberration characteristics shown in fig. 10.

An optical imaging system 600 according to a sixth exemplary embodiment will be described with reference to fig. 11 and 12.

The optical imaging system 600 in the sixth exemplary embodiment may include an optical system including the first lens 610, the second lens 620, the third lens 630, the fourth lens 640, and the fifth lens 650, and may further include the optical filter 670 and the image sensor IS.

The optical imaging system 600 according to the sixth exemplary embodiment can form an in-focus image on the imaging plane 680 of the image sensor IS. The imaging plane 680 may refer to a surface on which an in-focus image is formed by the optical imaging system 600. In an example, the imaging plane 680 may refer to one surface of the image sensor IS on which light IS received.

Although not shown in fig. 11, the optical imaging system 600 may further include a reflective member R disposed in front of the first lens 610 and having a reflective surface that changes a path of light. In the sixth exemplary embodiment, the reflecting member R may be a prism, but may also be implemented as a mirror.

Lens characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index, abbe number and focal length) of each lens are listed in table 11 below.

TABLE 11

Noodle numbering	Marking	Radius of curvature	Thickness or distance	Refractive index	Abbe number	Focal length
							S1	First lens	4.3645	1.978	1.537	55.7	6.910
S2		-20.7455	0.130
							S3	Second lens	-19.5126	0.604	1.644	23.5	-7.10304
S4		6.04801	1.153
							S5	Third lens	5.10122	0.878	1.656	21.5	17.923
S6		8.39967	0.325
							S7	Fourth lens	7.26265	0.500	1.667	20.4	229.705
S8		7.41438	2.800
							S9	Fifth lens element	14.3727	0.618	1.537	55.7	-20.4303
S10		6.12583	3.000
							S11	Light filter	Infinity(s)	0.210	1.518	64.2
S12		Infinity(s)	1.901
							S13	Image plane	Infinity(s)

The optical imaging system 600 in the sixth exemplary embodiment has an overall focal length f of 15.0001mm and an IMG HT of 5.644 mm.

In the sixth exemplary embodiment, the first lens 610 may have a positive refractive power, and a first surface of the first lens 610 may be convex, and a second surface of the first lens 610 may be convex.

Second lens 620 may have a negative refractive power, and a first surface of second lens 620 may be concave and a second surface of second lens 620 may be concave.

The third lens 630 may have a positive refractive power, a first surface of the third lens 630 may be convex, and a second surface of the third lens 630 may be concave.

The fourth lens 640 may have a positive refractive power, a first surface of the fourth lens 640 may be convex, and a second surface of the fourth lens 640 may be concave.

The fifth lens 650 may have a negative refractive power, a first face of the fifth lens 650 may be convex in a paraxial region, and a second face of the fifth lens 650 may be concave in the paraxial region.

In addition, the fifth lens 650 may have at least one inflection point formed on at least one of the first and second faces. In an example, the first face of the fifth lens 650 may be convex in the paraxial region and concave in a portion or region other than the paraxial region. The second face of the fifth lens 650 may be concave in the paraxial region and convex in a portion or region other than the paraxial region.

Each surface of the first through fifth lenses 610 through 650 may have an aspheric coefficient as shown in table 12 below. In an example, both the object side and the image side of the first through fifth lenses 610 through 650 may be aspheric.

TABLE 12

In addition, the optical imaging system 600 of the above configuration may have aberration characteristics shown in fig. 12.

An optical imaging system 700 according to a seventh exemplary embodiment will be described with reference to fig. 13 and 14.

The optical imaging system 700 in the seventh exemplary embodiment may include an optical system including a first lens 710, a second lens 720, a third lens 730, a fourth lens 740, and a fifth lens 750, and may further include an optical filter 770 and an image sensor IS.

The optical imaging system 700 in the seventh exemplary embodiment can form an in-focus image on the imaging plane 780 of the image sensor IS. The imaging plane 780 may refer to a surface on which an in-focus image is formed by the optical imaging system 700. In an example, the imaging plane 780 may refer to a surface of the image sensor IS on which light IS received.

Although not shown in fig. 13, the optical imaging system 700 may further include a reflective member R (see fig. 15) disposed in front of the first lens 710 and having a reflective surface that changes a path of light. In the seventh exemplary embodiment, the reflecting member R may be a prism, but may also be implemented as a mirror.

Lens characteristics (radius of curvature, thickness of lens or distance between lenses, refractive index, abbe number and focal length) of each lens are listed in table 13 below.

Watch 13

The optical imaging system 700 in the seventh exemplary embodiment has an overall focal length f of 15mm and an IMG HT of 5.4 mm.

In the seventh exemplary embodiment, the first lens 710 may have a positive refractive power, and the first surface of the first lens 710 may be convex, and the second surface of the first lens 710 may be convex.

The second lens 720 may have a negative refractive power, a first surface of the second lens 720 may be convex, and a second surface of the second lens 720 may be concave.

The third lens 730 may have a negative refractive power, a first surface of the third lens 730 may be convex, and a second surface of the third lens 730 may be concave.

Fourth lens 740 may have a positive optical power, a first surface of fourth lens 740 may be concave, and a second surface of fourth lens 740 may be convex.

The fifth lens 750 may have a negative refractive power, a first face of the fifth lens 750 may be convex in a paraxial region, and a second face of the fifth lens 750 may be concave in the paraxial region.

In addition, the fifth lens 750 may have at least one inflection point formed on at least one of the first and second faces. In an example, the first face of the fifth lens 750 may be convex in the paraxial region and concave in a portion or region other than the paraxial region. The second face of the fifth lens 750 may be concave in the paraxial region and convex in a portion or region other than the paraxial region.

Each of the surfaces of the first lens 710 to the fifth lens 750 may have aspheric coefficients as shown in table 14 below. In an example, both the object side and the image side of the first through fifth lenses 710 through 750 may be aspheric.

TABLE 14

Further, the optical imaging system 700 of the above configuration may have aberration characteristics shown in fig. 14.

As described above, according to the optical imaging system of one or more examples described above, a high-resolution image can be captured.

While the present 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 herein 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 still be achieved 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 is defined not by the specific embodiments 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 comprising:

a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged in this order from an object side to an image side, wherein:

the optical imaging system further includes an image sensor configured to convert optical signals passing through the first to fifth lenses into electrical signals;

the first lens has a positive refractive power and the second lens has a negative refractive power; and

TTL is more than 10.2mm, and TTL/(2 × IMG HT) is less than or equal to 1.7,

wherein TTL is a distance from an object side surface of the first lens element to an imaging plane on an optical axis, and IMG HT is equal to half a diagonal length of the imaging plane.

2. The optical imaging system of claim 1, wherein:

IMG HT≥4.5mm。

3. the optical imaging system of claim 1, wherein:

1.5<f/IMG HT<3.5，

wherein f is the total focal length of the optical imaging system.

4. The optical imaging system of claim 1, wherein:

n2+n3>3.20，

wherein n2 is a refractive index of the second lens, and n3 is a refractive index of the third lens.

5. The optical imaging system of claim 1, wherein:

|f/f1+f/f2|<1.2，

wherein f is an overall focal length of the optical imaging system, f1 is a focal length of the first lens, and f2 is a focal length of the second lens.

6. The optical imaging system of claim 1, wherein:

BFL/f<0.4,

wherein f is a total focal length of the optical imaging system, and BFL is a distance from an image-side surface of the fifth lens to the imaging surface on the optical axis.

7. The optical imaging system of claim 1, wherein:

0.80≤TTL/f≤1.05，

wherein f is the total focal length of the optical imaging system.

8. The optical imaging system of claim 1, wherein:

0≤D1/f≤0.05，

where f is the total focal length of the optical imaging system, and D1 is the distance on the optical axis between the image-side surface of the first lens and the object-side surface of the second lens.

9. The optical imaging system of claim 1, wherein:

R1/f≤0.35,

where f is the total focal length of the optical imaging system, and R1 is the radius of curvature of the object side surface of the first lens.

10. The optical imaging system of claim 1, wherein:

the third lens has a positive refractive power, the fourth lens has a negative refractive power, and the fifth lens has a negative refractive power.

11. The optical imaging system of claim 1, wherein:

the third lens has a positive refractive power, the fourth lens has a positive refractive power, and the fifth lens has a negative refractive power.

12. The optical imaging system of claim 1, wherein:

the third lens has a negative refractive power, the fourth lens has a positive refractive power, and the fifth lens has a negative refractive power.

13. The optical imaging system of claim 1, further comprising:

a sixth lens disposed between the fifth lens and the imaging surface, wherein:

the third lens has a positive refractive power, the fourth lens has a positive refractive power, the fifth lens has a negative refractive power, and the sixth lens has a negative refractive power.

14. The optical imaging system of claim 1, further comprising:

a sixth lens disposed between the fifth lens and the imaging surface, wherein:

the third lens has a positive refractive power, the fourth lens has a positive refractive power, the fifth lens has a positive refractive power, and the sixth lens has a negative refractive power.

15. The optical imaging system of claim 1, wherein:

at least one of the second lens and the third lens has a refractive index greater than 1.64.

16. The optical imaging system of claim 1, wherein:

an absolute value of a focal length of each of the first lens and the second lens is smaller than an absolute value of a focal length of each of the third lens, the fourth lens, and the fifth lens.