CN115437118A

CN115437118A - Imaging lens system, camera module, and electronic apparatus

Info

Publication number: CN115437118A
Application number: CN202211234678.7A
Authority: CN
Inventors: 许宰赫; 郑有镇; 梁召渼; 徐立
Original assignee: Samsung Electro Mechanics Co Ltd
Current assignee: Samsung Electro Mechanics Co Ltd
Priority date: 2021-10-07
Filing date: 2022-09-29
Publication date: 2022-12-06

Abstract

The present disclosure relates to an imaging lens system, including: an optical path folding member including a frontmost reflection surface, a rearmost reflection surface, and a rear reflection surface, wherein the frontmost reflection surface is disposed closest to the object side, the rearmost reflection surface is disposed closest to the imaging plane, and the rear reflection surface is disposed to form an acute angle with the rearmost reflection surface and is configured to reflect light reflected by the rearmost reflection surface to the imaging plane; and a first lens group disposed on an object side of the frontmost reflective surface or an image side of the frontmost reflective surface, wherein an angle between a first virtual plane including the frontmost reflective surface and a second virtual plane including the frontmost reflective surface is 15 to 27 degrees. The present disclosure also relates to a camera module including the imaging lens system and an electronic device including the camera module.

Description

Imaging lens system, camera module, and electronic apparatus

Cross Reference to Related Applications

This application claims the benefit of priority from korean patent application No. 10-2021-0133480, filed on korean intellectual property office at 10/7/2021, and korean patent application No. 10-2022-0043821, filed on korean intellectual property office at 4/8/2022, the entire disclosures of which are incorporated herein by reference for all purposes.

Technical Field

The present disclosure relates to a telephoto imaging lens system that can be mounted on a portable electronic device.

Background

It may be not easy to implement an imaging lens system having a long focal length and reduced thickness and size (hereinafter referred to as a telephoto imaging lens system), and thus such a system may be difficult to install in a small-sized terminal. However, there is an increasing demand for improvement in the functions and performance of small-sized terminals (e.g., smart phones), which may result in an increasing demand for mounting telephoto imaging lens systems in such small-sized terminals.

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

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 one general aspect, an imaging lens system includes: an optical path folding member including a frontmost reflection surface, a rearmost reflection surface, and a rear reflection surface, wherein the frontmost reflection surface is disposed closest to the object side, the rearmost reflection surface is disposed closest to the imaging plane, and the rear reflection surface is disposed to form an acute angle with the rearmost reflection surface and is configured to reflect light reflected by the rearmost reflection surface to the imaging plane; and a first lens group disposed on an object side of the frontmost reflective surface or an image side of the frontmost reflective surface, wherein an angle between a first virtual plane including the frontmost reflective surface and a second virtual plane including the frontmost reflective surface is 15 to 27 degrees.

The first lens group may include a first lens and a second lens sequentially disposed from the object side.

The first lens may have a positive refractive power, and the second lens may have a negative refractive power.

V1-V2 may be greater than 30, where V1 is the Abbe number of the first lens and V2 is the Abbe number of the second lens.

The angle between the last reflective surface and the back reflective surface may be 18 to 30 degrees.

The optical path folding member may further include a first optical path folding member having a frontmost reflection surface and a second optical path folding member having a rear reflection surface and a rearmost reflection surface.

The imaging lens system may further include a second lens group disposed on the most front reflection surface on the object side or the image side where the first lens group is not disposed.

The second lens group may include one or more lenses.

The BFL/TTL may be less than 0.9, where BFL is a distance from an image side surface of a last lens of the first lens group to an imaging surface, and TTL is a distance from an object side surface of a foremost lens of the first lens group to the imaging surface.

The camera module may include an imaging lens system and an image sensor, wherein the imaging plane may be disposed on the image sensor.

The electronic device may include a camera module in which the image sensor is disposed diagonally with respect to a thickness direction of the electronic device.

In another general aspect, an imaging lens system includes: a first optical path folding member having one reflection surface and having a sectional shape of a right triangle; a second optical path folding member having two or more reflection surfaces and having a sectional shape of a right triangle; a lens unit disposed to face an incident surface or an exit surface of the first optical path folding member; and an imaging surface disposed to face the total reflection surface of the second optical path folding member, wherein the first optical path folding member, the second optical path folding member, and the imaging surface are sequentially arranged along the optical axis of the lens unit.

The second optical path folding member may include a first reflection surface reflecting the light emitted from the first optical path folding member, and a second reflection surface reflecting the light reflected from the first reflection surface to the first reflection surface.

The angle between the first reflective surface and the second reflective surface may be 16 degrees to 32 degrees.

The maximum length of the incident surface of the first light path folding member may be less than the maximum length of the exit surface of the second light path folding member.

A distance from the exit surface of the first light path folding member to the incident surface of the second light path folding member may be greater than a distance from the exit surface of the second light path folding member to the imaging plane.

The lens unit may include a first lens group disposed on the object side of the first optical path folding member.

The lens unit may include a first lens group disposed between the first optical path folding member and the second optical path folding member.

The lens unit may include a first lens group disposed on the object side of the first optical path folding member, and a second lens group disposed between the first optical path folding member and the second optical path folding member.

The camera module may include an imaging lens system.

The electronic device may include a camera module, wherein the imaging plane may be disposed on the image sensor, and the image sensor may be disposed diagonally with respect to a thickness direction of the electronic device.

In another general aspect, an imaging lens system includes: an optical path folding member including a first reflection surface, a second reflection surface, and a third reflection surface configured to sequentially reflect light incident from an object side; and a first lens group disposed on an object side or an image side of the first reflection surface, wherein a first incident angle of the first reflection surface is smaller than a second incident angle of the second reflection surface, and a third incident angle of the third reflection surface is smaller than the first incident angle of the first reflection surface.

The first and second incident angles may be greater than a critical angle of the first and second reflective surfaces, respectively, and the third incident angle may be less than a critical angle of the third reflective surface.

The first incident angle and the second incident angle may be greater than 36 degrees and less than 90 degrees, respectively.

The third incident angle may be greater than 28 degrees and less than 56 degrees.

The imaging surface may be disposed to face the second reflective surface.

The electronic device may include: a camera module including an imaging lens system; and an image sensor including an imaging surface disposed to face the second reflection surface, wherein the image sensor may be disposed diagonally with respect to a thickness direction of the electronic apparatus.

In another general aspect, an imaging lens system includes: a first lens having a positive refractive power; a second lens having a negative refractive power, a convex object-side surface and a concave image-side surface; a third lens having a refractive power and a concave image side surface; and a first reflection surface, a second reflection surface, and a third reflection surface that are arranged in order from the object side along the optical axis, wherein the first lens, the second lens, the third lens, the second reflection surface, and the third reflection surface are arranged in order from the object side along the optical axis.

An angle between a first virtual plane including the first reflective surface and a second virtual plane including the second reflective surface may be 15 degrees to 27 degrees.

The imaging lens system may further include an imaging plane disposed along the optical axis and parallel to a virtual plane including the second reflecting surface.

The first incident angle of the first reflective surface may be smaller than the second incident angle of the second reflective surface, and the third incident angle of the third reflective surface may be smaller than the first incident angle of the first reflective surface.

The imaging lens system may further include a fourth lens having an optical power and disposed between the first and second reflective surfaces along the optical axis.

The imaging lens system may further include a fourth reflective surface and a fifth reflective surface disposed between the first reflective surface and the second reflective surface along the optical axis.

The optical axis may extend a plurality of times between the second reflective surface and the third reflective surface.

The third lens may be disposed between the first reflective surface and the second reflective surface along the optical axis.

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 of an imaging lens system according to a first exemplary embodiment.

Fig. 2 is an aberration curve of the imaging lens system shown in fig. 1.

Fig. 3 is a configuration diagram of a modified example of the imaging lens system shown in fig. 1.

Fig. 4 is a configuration diagram of another modified example of the imaging lens system shown in fig. 1.

Fig. 5 is a diagram of an imaging lens system according to a second exemplary embodiment.

Fig. 6 is an aberration curve of the imaging lens system shown in fig. 5.

Fig. 7 is a diagram of an imaging lens system according to a third exemplary embodiment.

Fig. 8 is an aberration curve of the imaging lens system shown in fig. 7.

Fig. 9 is a configuration diagram of a modified example of the imaging lens system shown in fig. 7.

Fig. 10 is a configuration diagram of another modified example of the imaging lens system shown in fig. 7.

Fig. 11 is a diagram of an imaging lens system according to a fourth exemplary embodiment.

Fig. 12 is an aberration curve of the imaging lens system shown in fig. 11.

Fig. 13 is a diagram of an imaging lens system according to a fifth exemplary embodiment.

Fig. 14 is an aberration curve of the imaging lens system shown in fig. 13.

Fig. 15 is a diagram of an imaging lens system according to a sixth exemplary embodiment.

Fig. 16 is an aberration curve of the imaging lens system shown in fig. 15.

Fig. 17 is a diagram of an imaging lens system according to a seventh exemplary embodiment.

Fig. 18 is an aberration curve of the imaging lens system shown in fig. 17.

Fig. 19 is a diagram of an imaging lens system according to an eighth exemplary embodiment.

Fig. 20 is an aberration curve of the imaging lens system shown in fig. 19.

Fig. 21 is a perspective view of an electronic device according to an example embodiment.

Fig. 22 is a partial cross-sectional view of the electronic device taken along line I-I shown in fig. 21.

Like reference numerals refer to like elements throughout the drawings and the 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

Hereinafter, although exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings, for example, it should be noted that the exemplary embodiments are not limited thereto. Terms representing components of the present disclosure may be named in consideration of functions of each component. Therefore, these terms should not be construed as limiting technical components of the present disclosure.

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 after understanding the present disclosure. 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 varied as will be apparent upon understanding the present disclosure. In addition, descriptions of features well known in the art may be omitted for the sake of clarity and conciseness.

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 present disclosure.

Throughout this disclosure, 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 items; likewise, "at least one" includes any one of the associated listed items as well as any combination of any two or more of the associated listed 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 8230; \8230", "above", "below", "8230", and the like may be used herein for convenience of description to describe the relationship of one element 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 "over" encompasses both orientations of "over" and "under", depending on the spatial orientation of the device, 8230 \8230 @. 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 "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.

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 manufacture.

It should be noted that use of the word "may" with respect to an example herein, such as with respect to what an example may include or implement, means that there is at least one example in which such features are included or implemented, and all examples are not so limited.

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

An aspect of the present disclosure may provide a telephoto imaging lens system having a long focal length, which may be mounted in a small-sized terminal.

In the present disclosure, the first lens may indicate a lens closest to an object (or object). Further, the number of the lenses may indicate an order in which the lenses are arranged from the object side in the optical axis direction. For example, the second lens may indicate a lens disposed at a second position from the object side, and the third lens may indicate a lens disposed at a third position from the object side. In the present disclosure, the radius of curvature and thickness of the lens, TTL (i.e., the distance from the object side surface of the first lens to the imaging plane), 2IMG HT (i.e., the diagonal length of the imaging plane), IMG HT (i.e., the height of the imaging plane or 1/2 of 2IMG HT), and focal length may be expressed in millimeters (mm).

The thickness of the lenses, the distance between the lenses, TTL, and the incident angle may be dimensions calculated on the optical axis of the imaging lens system, respectively. Further, in the description of the lens shape, one convex surface of the lens may indicate that a paraxial region of the corresponding surface is convex, and one concave surface of the lens may indicate that a paraxial region of the corresponding surface is concave. Therefore, even in the case where it is described that one surface of the lens is convex, the edge portion of the lens may be concave. Also, even in the case where it is described that one surface of the lens is concave, the edge portion of the lens may be convex.

The imaging lens systems described herein may be installed in portable electronic devices. For example, the imaging lens system may be installed in a smart phone, a laptop computer, an augmented reality device, a virtual reality device, a portable game machine, or the like. However, the scope and use examples of the imaging lens system described herein may not be limited to the above-described electronic devices. For example, the imaging lens system is applicable to electronic devices that may require high-resolution imaging while providing a narrow installation space.

The imaging lens system described herein can reduce the outer dimensions of the imaging lens system while ensuring a long back focal length (BFL, i.e., the distance from the image-side surface of the last lens to the imaging plane). For example, the imaging lens system in the present disclosure can reduce the outer size of the imaging lens system by using a reflective member while ensuring that the BFL required for the telephoto imaging lens system is achieved. In another example, the imaging lens system in the present disclosure may provide an imaging plane having a considerably large size for realizing high resolution. In another example, the imaging lens system in the present disclosure may have an integrated form installed in the portable terminal while ensuring a long focal length and a long BFL.

In the present disclosure, the light path folding member may indicate any member that may allow light to be reflected. For example, the optical path folding member may collectively refer to all reflectors, prisms, and the like. Therefore, in the present disclosure, the reflector, the prism, and the optical path folding member may all refer to the same component or interchangeable components.

The imaging lens system according to the first exemplary embodiment of the present disclosure may include an optical path folding member and a first lens group. In the imaging lens system according to the first exemplary embodiment, the optical path folding member may include a plurality of reflection surfaces. For example, the optical path folding member may include a frontmost reflective surface, a rearmost reflective surface, and a rear reflective surface. The frontmost reflective surface may be disposed closest to the object side, and the rearmost reflective surface may be disposed closest to the imaging plane. The rear reflection surface may be disposed to form an acute angle with the final reflection surface and reflect the light reflected by the final reflection surface to the image plane.

In the imaging lens system according to the present exemplary embodiment, the first lens group may be disposed on the object side of the frontmost reflective surface or on the image side of the frontmost reflective surface. However, the first lens group may not be limited to the above-described arrangement. The first lens group may include a plurality of lenses. For example, the first lens group may include a first lens and a second lens arranged in order from the object side. In the above arrangement, the first lens may have a positive refractive power, and the second lens may have a negative refractive power.

In the imaging lens system according to the present exemplary embodiment, the reflection surfaces of the optical path folding member may have a unique geometric relationship therebetween. For example, the angle between the frontmost reflective surface and the rearmost reflective surface may be 15 to 27 degrees. In another example, an angle between a first virtual plane including the frontmost reflective surface and a second virtual plane including the rearmost reflective surface may be 15 degrees to 27 degrees. In another example, the angle between the last reflective surface and the back reflective surface may be 18 to 30 degrees.

The optical path folding member may include a plurality of members. For example, the optical path folding member may include a first optical path folding member having a frontmost reflection surface and a second optical path folding member having a rear reflection surface and a rearmost reflection surface. The first and second optical path folding members may each have a shape of a prism. However, the first and second light path folding members may not be limited to the shape of the prism. For example, the first and second light path folding members may each have a shape of a reflector.

The imaging lens system according to the exemplary embodiment may include a plurality of lens groups. For example, the imaging lens system may further include a second lens group disposed on the object side or the image side of the frontmost reflective surface on which the first lens group is not disposed. As a specific example, the imaging lens system may include a first lens group disposed on the object side of the frontmost reflective surface and a second lens group disposed on the image side of the frontmost reflective surface. The first lens group and the second lens group may each include one or more lenses. For example, the first lens group may include two lenses, and the second lens group may include one lens. In another example, the first lens group may include three lenses, and the second lens group may include two lenses. In another example, the first lens group may include two lenses, and the second lens group may include three lenses. However, the lenses included in the first lens group or the second lens group may not be limited to the above number.

The imaging lens system according to the second exemplary embodiment of the present disclosure may include a first optical path folding member, a second optical path folding member, and an imaging surface, which are sequentially arranged from the object side. In the imaging lens system according to the second exemplary embodiment, the first optical path folding member and the second optical path folding member may each have a cross-sectional shape of a right triangle. For example, the first and second optical path folding members may be prisms having a cross-sectional shape of a right triangle, respectively. The imaging lens system according to the second exemplary embodiment may further include a member that condenses (or images) incident light to an imaging surface. For example, the imaging lens system according to the second exemplary embodiment may further include a lens unit disposed to face the incident surface or the exit surface of the first optical path folding member. In the imaging lens system according to the second exemplary embodiment, the imaging plane may be disposed on one side of the second optical path folding member. For example, the imaging plane may be disposed to face the hypotenuse (or the total reflection surface) of the second optical path folding member.

The first and second light path folding members may each include one or more reflective surfaces. For example, the first light path folding member may have one reflective surface, and the second light path folding member may have two or more reflective surfaces. As a specific example, the first optical path folding member may include one total reflection surface, and the second optical path folding member may include one total reflection surface and one mirror reflection surface (or mirror reflection surface). The total reflection surface of the second optical path folding member may reflect the light emitted from the first optical path folding member, and the specular reflection surface may reflect the light emitted from the total reflection surface to the total reflection surface (or an image plane).

In the imaging lens system according to the present exemplary embodiment, the second optical path folding member may have a unique shape. For example, the angle between the total reflection surface and the specular reflection surface of the second optical path folding member may be 16 to 32 degrees. As a specific example, the angle between the total reflection surface and the specular reflection surface of the second optical path folding member may be 30 degrees or 18 degrees.

In the imaging lens system according to the present exemplary embodiment, the second optical path folding member may realize multiple internal reflections. In more detail, the second light path folding member may allow an even number of internal reflections. For example, the second light path folding member may allow two or four internal reflections.

In the imaging lens system according to the present exemplary embodiment, an angle (θ P2) between the first reflecting surface and the second reflecting surface of the second optical path folding member may be represented by the following conditional expression.

θP2＝90/(2n+1),2n＝N

In the above conditional expressions, "N" may represent a positive integer, and "N" may represent the number of times of internal reflection by the second optical path folding member. For example, when the number of times of internal reflection by the second optical path folding member is two, the angle (θ P2) may be 30 degrees. In another example, when the number of times of internal reflection of the second optical path folding member is four, the angle (θ P2) may be 18 degrees.

The number of internal reflections of the second light path folding member according to the present exemplary embodiment may be six or more. However, the number of internal reflections of the second light path folding member may not exceed four. In more detail, when the number of internal reflections of the second optical path folding member is increased to six or more, the angle (θ P2) may be decreased to 12.9 degrees or less. In this case, the amount of light incident on the second optical path folding member may also be reduced, and the imaging lens system may thus have a significantly reduced resolution. Therefore, the number of internal reflections of the second optical path folding member may be two or four.

In the imaging lens system according to the present exemplary embodiment, the first optical path folding member and the second optical path folding member may have a unique dimensional relationship therebetween. For example, the maximum length of the incident surface of the first light path folding member may be less than the maximum length of the exit surface of the second light path folding member. In another example, the total reflection surface of the first optical path folding member may be smaller than the total reflection surface of the second optical path folding member.

In the imaging lens system according to the present exemplary embodiment, the second optical path folding member may be disposed adjacent to the imaging surface. For example, the distance from the exit surface of the second light path folding member to the imaging plane may be smaller than the distance from the exit surface of the first light path folding member to the entrance surface of the second light path folding member.

In the imaging lens system according to the present exemplary embodiment, the lens unit may include a plurality of lens groups. For example, the lens unit may include a first lens group disposed on the object side of the first optical path folding member and a second lens group disposed between the first optical path folding member and the second optical path folding member.

An imaging lens system according to a third exemplary embodiment of the present disclosure may include an optical path folding member and a first lens group. In the imaging lens system according to the present exemplary embodiment, the optical path folding member may include a unique configuration. For example, the optical path folding member may include a first reflection surface, a second reflection surface, and a third reflection surface that sequentially reflect light incident from the object side. The first, second, and third reflective surfaces may have a predetermined dimensional relationship therebetween based on the angle of incidence. For example, the first incident angle of the first reflective surface may be smaller than the second incident angle of the second reflective surface, and the third incident angle of the third reflective surface may be smaller than the first incident angle of the first reflective surface.

The first to third incident angles may each have a predetermined size. For example, the first incident angle and the second incident angle may be greater than 36 degrees and less than 90 degrees, respectively. In another example, the third angle of incidence may be greater than 28 degrees and less than 56 degrees.

The imaging lens system according to the present exemplary embodiment may have an imaging surface formed at a specific position. For example, in the imaging lens system according to the present exemplary embodiment, the imaging plane may be disposed to face the second reflection surface of the optical path folding member.

The imaging lens system according to the fourth exemplary embodiment of the present disclosure may satisfy one or more of the following conditional expressions. However, the imaging lens system according to only the fourth exemplary embodiment may not satisfy the following conditional expression. For example, the imaging lens systems according to the first to third exemplary embodiments described above may satisfy one or more of the following conditional expressions.

BFL/TTL<0.9

30<V1-V2

10mm<f

15mm<TTL

In the above conditional expressions, BFL may represent a distance from an image side surface of a lens (hereinafter, referred to as a last lens) disposed closest to an imaging surface to the imaging surface, TTL may represent a distance from an object side surface of a lens (hereinafter, referred to as a foremost lens or a first lens) disposed closest to an object (or object) to the imaging surface, V1 may represent an abbe number of the first lens (or foremost lens), V2 may represent an abbe number of the second lens (or a lens closest to the image side surface of the first lens), and f is a focal length of the imaging lens system.

The imaging lens system according to the present disclosure may satisfy the above-described conditional expression in a more limited form as follows.

0.4<BFL/TTL<0.9

30<V1-V2<36

12mm<f<24mm

15mm<TTL<26mm

The imaging lens system according to the fifth exemplary embodiment of the present disclosure may satisfy one or more of the following conditional expressions independently of the above conditional expressions.

0.8<TTL/f<1.5

1.8<TTL/f1<2.6

-3.4<TTL/f2<-0.2

-1.4<TTL/f3<1.4

-1.0<TTL/f4<1.0

0.4<BFL/f<1.0

0.9<BFL/f1<2.1

-3.0<BFL/f2<-0.1

-1.0<BFL/f3<1.0

-0.3<BFL/f4<0.4

5.0mm<PID<8.0mm

2.3<PID/IMG HT<6.0

In the above-described conditional expressions, f1 may represent a focal length of the first lens, f2 may represent a focal length of the second lens, f3 may represent a focal length of a lens (hereinafter, referred to as a third lens) disposed closest to an image-side surface of the second lens, f4 may represent a focal length of a lens (hereinafter, referred to as a fourth lens) disposed closest to an image-side surface of the third lens, PID may represent an optical path distance from an incident surface of an optical path folding member disposed closest to an imaging surface to an exit surface thereof, and IMG HT may represent a height of the imaging surface.

The imaging lens systems according to the first to fourth exemplary embodiments may include one or more lenses having the following characteristics, if necessary. For example, the imaging lens system according to the first exemplary embodiment may include one of the first to fourth lenses having the following characteristics. In another example, the imaging lens system according to the second exemplary embodiment may include two or more of the first to fourth lenses having the following characteristics. However, the imaging lens system according to the above-described exemplary embodiment may not necessarily include a lens having the following characteristics.

The first lens may have an optical power. For example, the first lens may have a positive refractive power. The first lens may have a convex surface. For example, the first lens may have a convex object side. The first lens may have a predetermined refractive index. For example, the refractive index of the first lens may be 1.5 or more. As a specific example, the refractive index of the first lens may be greater than 1.5 and less than 1.6. The first lens may have a predetermined abbe number. For example, the abbe number of the first lens may be 50 or more. As a specific example, the abbe number of the first lens may be greater than 52 and less than 62. The first lens may have a predetermined focal length. For example, the focal length of the first lens may be determined in the range of 7.6mm to 10.0 mm.

The second lens may have an optical power. For example, the second lens may have a negative refractive power. The second lens may have a convex surface. For example, the second lens may have a convex object side. The second lens may have a predetermined refractive index. For example, the refractive index of the second lens may be 1.6 or more. As a specific example, the refractive index of the second lens may be greater than 1.6 and less than 1.7. The second lens may have a predetermined abbe number. For example, the abbe number of the second lens may be 20 or more. As a specific example, the abbe number of the second lens may be greater than 20 and less than 30. The second lens may have a predetermined focal length. For example, the focal length of the second lens may be determined in the range of-60 mm to-6.0 mm.

The third lens may have an optical power. For example, the third lens may have a positive refractive power or a negative refractive power. The third lens may have a concave surface. For example, the third lens may have a concave image side surface. The third lens may have a predetermined refractive index. For example, the refractive index of the third lens may be 1.5 or more. As a specific example, the refractive index of the third lens may be greater than 1.5 and less than 1.7. The third lens may have a predetermined abbe number. For example, the third lens may have an abbe number of 18 or more. As a specific example, the third lens may have an abbe number greater than 18 and less than 60. The third lens may have a predetermined focal length. For example, the focal length of the third lens may be less than-10 mm or greater than 10mm.

The fourth lens may have an optical power. For example, the fourth lens may have a positive refractive power or a negative refractive power. The fourth lens may have a convex surface. For example, the fourth lens may have a convex object side. The fourth lens may have a predetermined refractive index. For example, the refractive index of the fourth lens may be 1.5 or more. As a specific example, the refractive index of the fourth lens may be greater than 1.5 and less than 1.6. The fourth lens may have a predetermined abbe number. For example, the abbe number of the fourth lens may be 50 or more. As a specific example, the abbe number of the fourth lens may be more than 50 and less than 60. The fourth lens may have a predetermined focal length. For example, the focal length of the fourth lens may be less than-20 mm or greater than 20mm.

The aspherical surfaces of the first to fourth lenses may be represented by equation 1. In equation 1, "c" may represent an inverse of a curvature radius of the corresponding lens, "k" may represent a conic constant, "r" may represent a distance from a specific point on an aspherical surface of the lens to the optical axis, "a to H" and "J" may represent aspherical constants, and "Z" (or SAG) may represent a height from a specific point on an aspherical surface of the lens to a vertex of an aspherical surface of the corresponding lens in the optical axis direction.

Equation 1

The electronic device according to the first exemplary embodiment of the present disclosure may have a reduced thickness to be easily carried or stored. For example, an electronic device according to an exemplary embodiment may be a smart phone, a laptop computer, or the like. An electronic device according to an exemplary embodiment may include a camera module having a long focal length while enabling high resolution. For example, the electronic device may be equipped with a camera module including one of the imaging lens systems according to the first to fourth exemplary embodiments described above. However, the imaging lens system included in the camera module may not be limited to the imaging lens systems according to the first to fourth exemplary embodiments described above.

The electronic device according to the second exemplary embodiment may include a camera module having a unique shape. For example, the camera module may include an image sensor disposed to have a tilt with respect to an output unit (e.g., a liquid crystal screen) of the electronic device. As a specific example, the board on which the image sensor is mounted may be disposed to have an inclination of 16 degrees to 32 degrees with respect to the output unit of the electronic apparatus.

Hereinafter, exemplary embodiments in the present disclosure will now be described in detail with reference to the accompanying drawings.

First, an imaging lens system according to a first exemplary embodiment is described with reference to fig. 1.

The imaging lens system 100 according to the present exemplary embodiment may include a lens group LG, a first prism P1, and a second prism P2. However, the components of the imaging lens system 100 are not limited to the above-described members. For example, the imaging lens system 100 may further include a filter IF and an imaging plane IP. The lens group LG, the first prism P1, and the second prism P2 may be arranged in order from the object side. For example, the lens group LG may be disposed on the object side of the first prism P1, and the second prism P2 may be disposed on the image side of the first prism P1. However, the lens group LG, the first prism P1, and the second prism P2 are not limited to the above arrangement. For example, the lens group LG may be disposed on the image side of the first prism P1, that is, between the first prism P1 and the second prism P2.

Next, the above components are described in order.

The lens group LG may include a plurality of lenses. For example, the lens group LG may include a first lens 110, a second lens 120, and a third lens 130 arranged in order from the object side. The first to third lenses 110 to 130 may be arranged at predetermined intervals. For example, the image side surface of the first lens 110 may not be in contact with the object side surface of the second lens 120, and the image side surface of the second lens 120 may not be in contact with the object side surface of the third lens 130. However, the first to third lenses 110 to 130 may not necessarily be arranged so as not to contact each other. For example, the image side surface of the first lens 110 may be in contact with the object side surface of the second lens 120, or the image side surface of the second lens 120 may be in contact with the object side surface of the third lens 130.

Next, characteristics of the first lens 110 to the third lens 130 are described.

The first lens 110 may have optical power. For example, the first lens 110 may have a positive refractive power. The first lens 110 may have a convex object side surface and a concave image side surface. The first lens 110 may have a spherical surface. For example, both surfaces of the first lens 110 may be spherical. The second lens 120 may have an optical power. For example, the second lens 120 may have a negative refractive power. The second lens 120 may have a convex object side surface and a concave image side surface. The second lens 120 may have an aspherical surface. For example, both surfaces of the second lens 120 may be aspherical. The third lens 130 may have an optical power. For example, the third lens 130 may have a positive refractive power. The third lens 130 may have a convex object side surface and a concave image side surface. The third lens 130 may have an aspherical surface. For example, both surfaces of the third lens 130 may be aspherical.

Next, the first prism P1 and the second prism P2 as the optical path folding member are described. For reference, a prism described below is one type of the optical path folding member described in claims, and may be changed to another member.

The first and second prisms P1 and P2 may be disposed such that light incident through the first to third lenses 110 to 130 is imaged on the imaging plane IP. For example, the first prism P1 and the second prism P2 may be sequentially disposed along the optical path between the third lens 130 and the imaging plane IP.

The first prisms P1 may have a triangular cross-section. For example, a section of the first prism P1 cut in the optical path direction may have a right-angled triangle shape. The incident surface S7 of the first prism P1 and the projection surface S9 of the first prism P1 may form a substantially right angle. For example, the incident surface S7 of the first prism P1 and the projection surface S9 of the first prism P1 may be formed in portions other than the hypotenuse in the sectional shape of the right triangle, respectively.

The first prism P1 may include a reflective surface. For example, the first prism P1 may include a first reflecting surface S8. The first reflecting surface S8 can realize total reflection. For example, the first incident angle θ 1 of the first reflective surface S8 may be greater than the critical angle of the first reflective surface S8. In more detail, the first incident angle θ 1 may be 45 degrees greater than 41.2 degrees (i.e., a critical angle of the first reflection surface S8). The first prism P1 configured as described above can reflect the light incident from the third lens 130 to the second prism P2 as it is.

The second prisms P2 may have a triangular cross-section. For example, a section of the second prism P2 cut in the optical path direction may have a right-angled triangle shape. The second prism P2 may include a plurality of reflective surfaces. For example, the second prism P2 may include a second reflection surface S11 and a third reflection surface S12.

The second prism P2 can implement total reflection and specular reflection. For example, the second reflecting surface S11 of the second prism P2 may implement total reflection, and the third reflecting surface S12 of the second prism P2 may implement specular reflection or specular reflection. As a specific example, the second incident angle θ 2 of the second reflecting surface S11 may be greater than a critical angle of the second reflecting surface S11, and the third incident angle θ 3 of the third reflecting surface S12 may be less than a critical angle of the third reflecting surface S12.

The second reflecting surface S11 and the third reflecting surface S12 may form an acute angle. For example, the angle θ P2 between the second reflecting surface S11 and the third reflecting surface S12 may be 16 degrees to 32 degrees. The second and third reflection surfaces S11 and S12 may each have a predetermined angle with the incident surface S10 of the second prism P2. For example, an angle between the second reflection surface S11 and the incidence surface S10 of the second prism P2 may be 58 to 74 degrees, and an angle between the third reflection surface S12 and the incidence surface S10 of the second prism P2 may be about 90 degrees.

The second prism P2 can realize multiple internal reflections. For example, light incident through the incident surface S10 of the second prism P2 may be reflected by the second reflecting surface S11 and then reflected again by the third reflecting surface S12.

One surface of the second prism P2 can realize both reflection and projection. For example, the second reflection surface S11 of the second prism P2 may transmit light incident from the third reflection surface S12 while reflecting the light incident through the incidence surface S10 to the third reflection surface S12.

The first, second, and third reflecting surfaces S8, S11, and S12 of the first and second prisms P1 and P2 may have a predetermined dimensional relationship therebetween. For example, the first incident angle θ 1 may be smaller than the second incident angle θ 2, and the third incident angle θ 3 may be smaller than the first incident angle θ 1.

The first prism P1 and the second prism P2 configured as described above can miniaturize and integrate the imaging lens system 100 by folding the optical path connected from the object side to the imaging plane IP. For example, the first prism P1 may fold an optical path extending along the first optical axis C1 in a direction of a second optical axis C2 intersecting the first optical axis C1, thereby reducing the length of the imaging lens system 100 in the direction of the first optical axis C1. In another example, the second prism P2 may fold the optical path extending along the second optical axis C2 two or more times by total reflection and mirror reflection, thereby reducing the length of the imaging lens system 100 in the direction of the second optical axis C2.

The filter IF and the imaging plane IP may be disposed on one side of the second prism P2. For example, the filter IF and the imaging plane IP may be disposed to face a hypotenuse having the maximum length in the sectional shape of the second prism P2. As a specific example, the filter IF and the imaging plane IP may be disposed to face the second reflection surface S11 of the second prism P2.

The filter IF may block light of a particular wavelength. For example, the filter IF according to the present exemplary embodiment may block infrared light. However, the type of light blocked by the filter IF is not limited to infrared light. For example, the filter IF may block ultraviolet light or visible light.

The imaging plane IP may be located at a point where the light reflected by the third reflecting surface S12 converges or forms an image, and may be formed by the image sensor IS or the like. For example, the imaging plane IP may be formed on or inside the image sensor IS.

The imaging lens system 100 configured as above can exhibit the aberration characteristics shown in fig. 2. Table 1 and table 2 show lens characteristics and aspherical values of the imaging lens system according to the present exemplary embodiment, respectively.

TABLE 1

TABLE 2

Noodle numbering	S1	S2	S3	S4	S5	S6
							k
	0	0	3.847E+01	2.078E-01	-6.915E-01	9.200E+00
							A	0	0	1.319E-02	1.729E-02	5.342E-03	1.012E-03
B
		0	0	1.377E-03	-7.004E-04	-2.741E-04	-2.020E-04
C
		0	0	3.400E-04	-1.445E-04	2.866E-05	-7.257E-05
D
		0	0	3.735E-04	1.419E-04	-3.251E-05	-1.573E-04
E
		0	0	0	0	0	0
F								0	0	0	0	0	0
	G	0	0	0	0	0	0
H								0	0	0	0	0	0
	J	0	0	0	0	0	0

Next, a modified example of the imaging lens system according to the first exemplary embodiment is described with reference to fig. 3 and 4. For reference, in the following description, the same components as those of the above-described exemplary embodiments are denoted by the same reference numerals as those of the above-described exemplary embodiments, and detailed descriptions thereof are omitted.

First, an imaging lens system 101 according to a first modified example is described with reference to fig. 3.

The imaging lens system 101 according to the first modified example may include an optical path folding member P in which a first prism and a second prism are integrally formed with each other as shown in fig. 3. For example, the optical path folding member P may have the first prism P1 and the second prism P2 of fig. 1 coupled to each other.

The optical path folding member P may include three reflection surfaces. For example, the optical path folding member P may include a first reflection surface PS1, a second reflection surface PS2, and a third reflection surface PS3. The first, second, and third reflection surfaces PS1, PS2, and PS3 may be sequentially arranged along the optical path.

The optical path folding member P can achieve both total reflection and specular reflection (or specular reflection). For example, the first and second reflection surfaces PS1 and PS2 may implement total reflection, and the third reflection surface PS3 may implement specular reflection.

The first, second, and third reflection surfaces PS1, PS2, and PS3 may each have a predetermined incident angle. For example, the first incident angle θ 1 of the first reflection surface PS1 may be 45 degrees, the second incident angle θ 2 of the second reflection surface PS2 may be 60 degrees, and the third incident angle θ 3 of the third reflection surface PS3 may be 30 degrees.

The imaging lens system 101 configured as described above can replace a plurality of prisms with one optical path folding member P, thereby simplifying the assembly process of the imaging lens system 101.

Next, an imaging lens system 102 according to a second modified example is described with reference to fig. 4.

The imaging lens system 102 according to the second modified example can achieve a considerably long back focal length. For example, the imaging lens system 102 according to this modified example may include a second prism P2 that enables two or more internal reflections as shown in fig. 4. As a specific example, the second prism P2 may implement four internal reflections. For reference, the angle θ P2 between the second and third reflection surfaces S11 and S12 may be 18 degrees.

The imaging lens system 102 configured as described above can have a back focal length increased by multiple internal reflections achieved by the second prism P2 as described above, thereby improving the telephoto characteristic of the imaging lens system 102.

Next, an imaging lens system according to a second exemplary embodiment is described with reference to fig. 5.

The imaging lens system 200 according to the present exemplary embodiment may include a lens group LG, a first prism P1, and a second prism P2. However, the components of the imaging lens system 200 are not limited to the above-described members. For example, the imaging lens system 200 may further include a filter IF and an imaging plane IP. The lens group LG, the first prism P1, and the second prism P2 may be arranged in order from the object side. For example, the lens group LG may be disposed on the object side of the first prism P1, and the second prism P2 may be disposed on the image side of the first prism P1. However, the lens group LG, the first prism P1, and the second prism P2 are not limited to the above arrangement. For example, the lens group LG may be disposed on the image side of the first prism P1, that is, between the first prism P1 and the second prism P2.

Next, the above components are described in order.

The lens group LG may include a plurality of lenses. For example, the lens group LG may include a first lens 210, a second lens 220, and a third lens 230 arranged in order from the object side. The first to third lenses 210 to 230 may be arranged at predetermined intervals. For example, the image side surface of the first lens 210 may not be in contact with the object side surface of the second lens 220, and the image side surface of the second lens 220 may not be in contact with the object side surface of the third lens 230. However, the first to third lenses 210 to 230 may not necessarily be arranged so as not to contact each other. For example, the image side surface of the first lens 210 may be in contact with the object side surface of the second lens 220, or the image side surface of the second lens 220 may be in contact with the object side surface of the third lens 230.

Next, characteristics of the first to third lenses 210 to 230 are described.

The first lens 210 may have optical power. For example, the first lens 210 may have a positive refractive power. The first lens 210 may have a convex object side and a convex image side. The first lens 210 may have a spherical surface. For example, both surfaces of the first lens 210 may be spherical. The second lens 220 may have an optical power. For example, the second lens 220 may have a negative refractive power. The second lens 220 may have a convex object side surface and a concave image side surface. The second lens 220 may have an aspheric surface. For example, both surfaces of the second lens 220 may be aspherical. The third lens 230 may have optical power. For example, the third lens 230 may have a positive refractive power. The third lens 230 may have a convex object side surface and a concave image side surface. The third lens 230 may have an aspherical surface. For example, both surfaces of the third lens 230 may be aspherical.

The first and second prisms P1 and P2 may be disposed such that light incident through the first to third lenses 210 to 230 is imaged on the imaging plane IP. For example, the first prism P1 and the second prism P2 may be sequentially disposed along the optical path between the third lens 230 and the imaging plane IP.

The first prism P1 may include a reflective surface. For example, the first prism P1 may include a first reflecting surface S8. The first reflecting surface S8 can realize total reflection. For example, the first incident angle θ 1 of the first reflective surface S8 may be greater than the critical angle of the first reflective surface S8. In more detail, the first incident angle θ 1 may be 45 degrees greater than 41.2 degrees (i.e., a critical angle of the first reflection surface S8). The first prism P1 configured as described above may reflect the light incident from the third lens 230 to the second prism P2 as it is.

The second prism P2 may have a triangular cross-section. For example, a section of the second prism P2 cut in the optical path direction may have a right-angled triangle shape. The second prism P2 may include a plurality of reflective surfaces. For example, the second prism P2 may include a second reflection surface S11 and a third reflection surface S12.

The second prism P2 can implement total reflection and specular reflection. For example, the second reflecting surface S11 of the second prism P2 may implement total reflection, and the third reflecting surface S12 of the second prism P2 may implement specular reflection or specular reflection. As a specific example, the second incident angle θ 2 of the second reflective surface S11 may be greater than the critical angle of the second reflective surface S11, and the third incident angle θ 3 of the third reflective surface S12 may be less than the critical angle of the third reflective surface S12.

The second and third reflection surfaces S11 and S12 may form an acute angle. For example, the angle θ P2 between the second reflecting surface S11 and the third reflecting surface S12 may be 16 degrees to 32 degrees. The second and third reflection surfaces S11 and S12 may have a predetermined angle with the incident surface S10 of the second prism P2. For example, the angle between the second reflection surface S11 and the incident surface S10 of the second prism P2 may be 58 to 74 degrees, and the angle between the third reflection surface S12 and the incident surface S10 of the second prism P2 may be about 90 degrees.

The second prism P2 can realize multiple internal reflections. For example, light incident through the incident surface S10 of the second prism P2 may be reflected by the second reflection surface S11 and then reflected again by the third reflection surface S12.

The first prism P1 and the second prism P2 configured as described above can miniaturize and integrate the imaging lens system 200 by folding the optical path connected from the object side to the imaging plane IP. For example, the first prism P1 may fold an optical path extending along the first optical axis C1 in a direction of a second optical axis C2 intersecting the first optical axis C1, thereby reducing a length of the imaging lens system 200 in the direction of the first optical axis C1. In another example, the second prism P2 may fold the optical path extending along the second optical axis C2 two or more times by total reflection and mirror reflection, thereby reducing the length of the imaging lens system 200 in the direction of the second optical axis C2.

The imaging plane IP may be disposed on one side of the second prism P2. For example, the imaging plane IP may be disposed to face a hypotenuse having the maximum length in the sectional shape of the second prism P2. As a specific example, the imaging plane IP may be disposed to face the second reflecting surface S11 of the second prism P2.

In the imaging lens system 200 according to the present exemplary embodiment, a filter (not shown) may be integrally formed on one surface of the second prism P2. For example, the filter may be integrally formed on the incident surface S10 or the projection surface S11 of the second prism P2. As a specific example, the filter may be manufactured in a film shape and attached to the incident surface S10 or the projection surface S11 of the second prism P2.

The imaging lens system 200 configured as above can exhibit the aberration characteristics shown in fig. 6. Table 3 and table 4 show lens characteristics and aspherical values of the imaging lens system according to the present exemplary embodiment, respectively.

TABLE 3

TABLE 4

Noodle numbering	S1	S2	S3	S4	S5	S6
							k
	0	0	3.981E+01	2.311E-01	-2.494E+00	7.892E+01
							A	0	0	1.268E-02	1.661E-02	7.014E-03	-4.885E-03
B
		0	0	1.083E-03	-1.451E-04	-5.181E-04	-7.813E-04
C
		0	0	2.509E-05	5.160E-04	3.048E-05	3.334E-04
D
		0	0	4.678E-04	7.040E-07	8.988E-06	-5.540E-04
E
		0	0	0	0	0	0
F								0	0	0	0	0	0
	G	0	0	0	0	0	0
H								0	0	0	0	0	0
	J	0	0	0	0	0	0

Next, an imaging lens system according to a third exemplary embodiment is described with reference to fig. 7.

The imaging lens system 300 according to the present exemplary embodiment may include a first lens group LG1, a first prism P1, a second lens group LG2, and a second prism P2. However, the components of the imaging lens system 300 are not limited to the above-described members. For example, the imaging lens system 300 may further include a filter IF and an imaging plane IP. The first lens group LG1, the first prism P1, the second lens group LG2, and the second prism P2 may be arranged in order from the object side. For example, the first lens group LG1 may be disposed on the object side of the first prism P1, and the second lens group LG2 may be disposed between the first prism P1 and the second prism P2.

Next, the above components are described in order.

The first lens group LG1 may include a plurality of lenses. For example, the first lens group LG1 may include a first lens 310, a second lens 320, and a third lens 330, which are sequentially arranged from the object side. The first to third lenses 310 to 330 may be arranged at predetermined intervals. For example, the image side surface of the first lens 310 may not be in contact with the object side surface of the second lens 320, and the image side surface of the second lens 320 may not be in contact with the object side surface of the third lens 330. However, the first to third lenses 310 to 330 may not necessarily be arranged so as not to contact each other. For example, the image side surface of the first lens 310 may be in contact with the object side surface of the second lens 320, or the image side surface of the second lens 320 may be in contact with the object side surface of the third lens 330.

The second lens group LG2 may include one or more lenses. For example, the second lens group LG2 may include the fourth lens 340. However, the lenses included in the second lens group LG2 are not limited to the fourth lens 340. For example, the second lens group LG2 may further include a lens or may include the above-described filter IF.

Next, characteristics of the first lens 310 to the fourth lens 340 included in the first lens group LG1 and the second lens group LG2 are described.

The first lens 310 may have optical power. For example, the first lens 310 may have a positive refractive power. The first lens 310 may have a convex object side and a convex image side. The first lens 310 may have a spherical surface. For example, both surfaces of the first lens 310 may be spherical. The second lens 320 may have optical power. For example, the second lens 320 may have a negative refractive power. The second lens 320 may have a convex object side surface and a concave image side surface. The second lens 320 may have an aspherical surface. For example, both surfaces of the second lens 320 may be aspherical. The third lens 330 may have optical power. For example, the third lens 330 may have a positive refractive power. The third lens 330 may have a convex object side surface and a concave image side surface. The third lens 330 may have an aspheric surface. For example, both surfaces of the third lens 330 may be aspherical. The fourth lens 340 may have optical power. For example, the fourth lens 340 may have a positive refractive power. The fourth lens 340 may have a convex object side and a convex image side. The fourth lens 340 may have a spherical surface. For example, both surfaces of the fourth lens 340 may be spherical.

The first prism P1 and the second prism P2 may be disposed such that light incident through the first lens 310 to the fourth lens 340 is imaged on the imaging plane IP. For example, the first prism P1 and the second prism P2 may be sequentially disposed along the optical path between the third lens 330 and the imaging plane IP.

The first prism P1 may include a reflective surface. For example, the first prism P1 may include a first reflecting surface S8. The first reflection surface S8 can realize total reflection. For example, the first incident angle θ 1 of the first reflective surface S8 may be greater than the critical angle of the first reflective surface S8. In more detail, the first incident angle θ 1 may be 45 degrees greater than 41.2 degrees (i.e., a critical angle of the first reflection surface S8). The first prism P1 configured as described above may reflect the light incident from the third lens 330 to the second prism P2 as it is.

The second prisms P2 may have a triangular cross-section. For example, a section of the second prism P2 cut in the optical path direction may have a right-angled triangle shape. The second prism P2 may include a plurality of reflective surfaces. For example, the second prism P2 may include a second reflection surface S13 and a third reflection surface S14.

The second prism P2 can implement total reflection and specular reflection. For example, the second reflecting surface S13 of the second prism P2 may implement total reflection, and the third reflecting surface S14 of the second prism P2 may implement specular reflection or mirror reflection. As a specific example, the second incident angle θ 2 of the second reflecting surface S13 may be greater than a critical angle of the second reflecting surface S13, and the third incident angle θ 3 of the third reflecting surface S14 may be less than a critical angle of the third reflecting surface S14.

The second reflecting surface S13 and the third reflecting surface S14 may form an acute angle. For example, the angle θ P2 between the second reflecting surface S13 and the third reflecting surface S14 may be 16 degrees to 32 degrees. The second and third reflection surfaces S13 and S14 may have a predetermined angle with the incident surface S12 of the second prism P2. For example, an angle between the second reflection surface S13 and the incidence surface S12 of the second prism P2 may be 58 to 74 degrees, and an angle between the third reflection surface S14 and the incidence surface S12 of the second prism P2 may be about 90 degrees.

The second prism P2 can realize multiple internal reflections. For example, light incident through the incident surface S12 of the second prism P2 may be reflected by the second reflection surface S13 and then reflected again by the third reflection surface S14.

One surface of the second prism P2 can realize both reflection and projection. For example, the second reflection surface S13 of the second prism P2 may transmit light incident from the third reflection surface S14 while reflecting the light incident through the incidence surface S12 to the third reflection surface S14.

The first, second, and third reflecting surfaces S8, S13, and S14 of the first and second prisms P1 and P2 may have a predetermined dimensional relationship therebetween. For example, the first incident angle θ 1 may be smaller than the second incident angle θ 2, and the third incident angle θ 3 may be smaller than the first incident angle θ 1.

The first prism P1 and the second prism P2 configured as described above can miniaturize and integrate the imaging lens system 300 by folding the optical path connected from the object side to the imaging plane IP. For example, the first prism P1 may fold an optical path extending along the first optical axis C1 in a direction of a second optical axis C2 intersecting the first optical axis C1, thereby reducing a length of the imaging lens system 300 in the direction of the first optical axis C1. In another example, the second prism P2 may fold the optical path extending along the second optical axis C2 two or more times by total reflection and mirror reflection, thereby reducing the length of the imaging lens system 300 in the direction of the second optical axis C2.

The filter IF and the imaging plane IP may be disposed on one side of the second prism P2. For example, the filter IF and the imaging plane IP may be disposed to face a hypotenuse having the maximum length in the sectional shape of the second prism P2. As a specific example, the filter IF and the imaging plane IP may be disposed to face the second reflection surface S13 of the second prism P2.

The imaging plane IP may be located at a point where the light reflected by the third reflecting surface S14 converges or forms an image, and may be formed by the image sensor IS or the like. For example, the imaging plane IP may be formed on or inside the image sensor IS.

The imaging lens system 300 configured as above can exhibit the aberration characteristics shown in fig. 8. Table 5 and table 6 show lens characteristics and aspherical values of the imaging lens system according to the present exemplary embodiment, respectively.

TABLE 5

TABLE 6

Noodle number	S1	S2	S3	S4	S5	S6	S10	S11
									k
	0	0	4.25E+01	2.17E-01	-2.54E+00	7.89E+01	0	0
									A	0	0	1.16E-02	1.74E-02	7.08E-03	-5.72E-03	0	0
B	0	0	1.27E-03	-1.72E-04	-3.46E-04	-1.85E-03	0	0
									C	0	0	6.76E-05	2.88E-04	5.74E-06	5.10E-04	0	0
D	0	0	3.68E-04	3.51E-04	1.05E-04	-3.12E-04	0	0
									E	0	0	0	0	0	0	0	0
F	0	0	0	0	0	0	0	0
									G	0	0	0	0	0	0	0	0
H	0	0	0	0	0	0	0	0
									J	0	0	0	0	0	0	0	0

Next, a modified example of the imaging lens system according to the third exemplary embodiment is described with reference to fig. 9 and 10. For reference, in the following description, the same components as those of the above-described exemplary embodiments are denoted by the same reference numerals as those of the above-described exemplary embodiments, and detailed descriptions thereof are omitted.

First, an imaging lens system 301 according to a first modified example is described with reference to fig. 9.

The imaging lens system 301 according to the first modified example may further include a third prism P3. For example, the imaging lens system 301 may further include a third prism P3 disposed between the second lens group LG2 and the second prism P2.

The third prism P3 may include a reflective surface. For example, the third prism P3 may include one reflective surface P3SR. The reflective surface P3SR of the third prism P3 can achieve total reflection. For example, the incident angle of the reflective surface P3SR may be larger than the critical angle of the reflective surface P3SR. The third prism P3 may have a shape substantially the same as or similar to the shape of the first prism P1. However, the first and third prisms P1 and P3 may not necessarily have the same or similar shape.

The imaging lens system 301 configured as described above can have an easily extendable back focal length (BFL, i.e., the distance from the image-side surface of the fourth lens 340 to the imaging plane IP) without deforming the second prism P2 to have the shape shown in fig. 4.

Next, an imaging lens system 302 according to a second modified example is described with reference to fig. 10.

The imaging lens system 302 according to the second modified example may further include a third prism P3 and a fourth prism P4. For example, the imaging lens system 302 may further include a third prism P3 disposed between the first prism P1 and the second lens group LG2 and a fourth prism P4 disposed between the second lens group LG2 and the second prism P2.

The third prism P3 may include a reflective surface. For example, the third prism P3 may include one reflective surface P3SR. The reflective surface P3SR of the third prism P3 can implement total reflection. For example, the incident angle of the reflective surface P3SR may be larger than the critical angle of the reflective surface P3SR. The third prism P3 may have a shape substantially the same as or similar to the shape of the first prism P1. However, the first and third prisms P1 and P3 may not necessarily have the same or similar shape.

The fourth prism P4 may include a reflective surface. For example, the fourth prism P4 may include one reflective surface P4SR. The reflective surface P4SR of the fourth prism P4 may implement total reflection. For example, the incident angle of the reflective surface P4SR may be larger than the critical angle of the reflective surface P4SR. The fourth prism P4 may have a shape substantially the same as or similar to the shape of the first prism P1 or the third prism P3. However, the fourth prism P4 may not necessarily have the same or similar shape as the first prism P1 or the third prism P3.

The imaging lens system 302 configured as described above can have an integrated arrangement of the plurality of lens groups LG1 and LG2 and the imaging plane IP in a limited space by the plurality of prisms P1, P2, P3, and P4, and thus can be easily mounted in an electronic device (e.g., a portable terminal) having a narrow mounting space.

Next, an imaging lens system according to a fourth exemplary embodiment is described with reference to fig. 11.

The imaging lens system 400 according to the present exemplary embodiment may include a first lens group LG1, a first prism P1, a second lens group LG2, and a second prism P2. However, the components of the imaging lens system 400 are not limited to the above-described members. For example, the imaging lens system 400 may further include a filter IF and an imaging plane IP. The first lens group LG1, the first prism P1, the second lens group LG2, and the second prism P2 may be arranged in order from the object side. For example, the first lens group LG1 may be disposed on the object side of the first prism P1, and the second lens group LG2 may be disposed between the first prism P1 and the second prism P2.

Next, the above components are described in order.

The first lens group LG1 may include a plurality of lenses. For example, the first lens group LG1 may include a first lens 410 and a second lens 420 disposed in order from the object side. The first lens 410 and the second lens 420 may be disposed at a predetermined interval. For example, the image side surface of the first lens 410 may not be in contact with the object side surface of the second lens 420. However, the first lens 410 and the second lens 420 may not necessarily be disposed not to contact each other. For example, the image side surface of the first lens 410 may be in contact with the object side surface of the second lens 420.

The second lens group LG2 may include one or more lenses. For example, the second lens group LG2 may include the third lens 430. However, the lenses included in the second lens group LG2 are not limited to the third lens 430.

Next, characteristics of the first lens 410 to the third lens 430 included in the first lens group LG1 and the second lens group LG2 are described.

The first lens 410 may have optical power. For example, the first lens 410 may have a positive refractive power. The first lens 410 may have a convex object side and a convex image side. The first lens 410 may have a spherical surface. For example, both surfaces of the first lens 410 may be spherical. The second lens 420 may have an optical power. For example, the second lens 420 may have a negative refractive power. The second lens 420 may have a convex object side surface and a concave image side surface. The second lens 420 may have an aspherical surface. For example, both surfaces of the second lens 420 may be aspherical. The third lens 430 may have an optical power. For example, the third lens 430 may have a positive refractive power. The third lens 430 may have a convex object side surface and a concave image side surface. The third lens 430 may have a spherical surface and an aspherical surface. For example, the object side surface of the third lens 430 may be spherical, and the image side surface of the third lens 430 may be aspherical.

The first and second prisms P1 and P2 may be disposed such that light incident through the first to third lenses 410 to 430 is imaged on the imaging plane IP. For example, the first prism P1 and the second prism P2 may be sequentially disposed along the optical path between the second lens 420 and the imaging plane IP.

The first prisms P1 may have a triangular cross-section. For example, a section of the first prism P1 cut in the optical path direction may have a right-angled triangle shape. The incident surface S5 of the first prism P1 and the projection surface S7 of the first prism P1 may form a substantially right angle. For example, the incident surface S5 of the first prism P1 and the projection surface S7 of the first prism P1 may be formed in portions other than the hypotenuse in the sectional shape of the right triangle, respectively.

The first prism P1 may include a reflective surface. For example, the first prism P1 may include a first reflecting surface S6. The first reflecting surface S6 can achieve total reflection. For example, the first incident angle θ 1 of the first reflective surface S6 may be greater than the critical angle of the first reflective surface S6. In more detail, the first incident angle θ 1 may be 45 degrees greater than 41.2 degrees (i.e., a critical angle of the first reflection surface S6). The first prism P1 configured as described above may reflect light incident from the second lens 420 to the third lens 430 and the second prism P2.

The second prism P2 can implement total reflection and specular reflection. For example, the second reflecting surface S11 of the second prism P2 may implement total reflection, and the third reflecting surface S12 of the second prism P2 may implement specular reflection or mirror reflection. As a specific example, the second incident angle θ 2 of the second reflecting surface S11 may be greater than a critical angle of the second reflecting surface S11, and the third incident angle θ 3 of the third reflecting surface S12 may be less than a critical angle of the third reflecting surface S12.

The second and third reflection surfaces S11 and S12 may form an acute angle. For example, the angle θ P2 between the second and third reflective surfaces S11 and S12 may be 16 to 32 degrees. The second and third reflection surfaces S11 and S12 may have a predetermined angle with the incident surface S10 of the second prism P2. For example, an angle between the second reflection surface S11 and the incidence surface S10 of the second prism P2 may be 58 to 74 degrees, and an angle between the third reflection surface S12 and the incidence surface S10 of the second prism P2 may be about 90 degrees.

The first, second, and third reflecting surfaces S6, S11, and S12 of the first and second prisms P1 and P2 may have a predetermined dimensional relationship therebetween. For example, the first incident angle θ 1 may be smaller than the second incident angle θ 2, and the third incident angle θ 3 may be smaller than the first incident angle θ 1.

The first prism P1 and the second prism P2 configured as described above can miniaturize and integrate the imaging lens system 400 by folding the optical path connected from the object side to the imaging plane IP. For example, the first prism P1 may fold an optical path extending along the first optical axis C1 in a direction of a second optical axis C2 intersecting the first optical axis C1, thereby reducing a length of the imaging lens system 400 in the direction of the first optical axis C1. In another example, the second prism P2 may fold the optical path extending along the second optical axis C2 two or more times by total reflection and mirror reflection, thereby reducing the length of the imaging lens system 400 in the direction of the second optical axis C2.

The filter IF and the imaging plane IP may be disposed on one side of the second prism P2. For example, the filter IF and the imaging plane IP may be disposed to face a hypotenuse having the maximum length in the sectional shape of the second prism P2. As a specific example, the filter IF and the imaging plane IP may be disposed to face the second reflecting surface S11 of the second prism P2.

The imaging lens system 400 configured as above can exhibit the aberration characteristics shown in fig. 12. Table 7 and table 8 show lens characteristics and aspherical values of the imaging lens system according to the present exemplary embodiment, respectively.

TABLE 7

Noodle numbering	Component part	Radius of curvature	Thickness/distance	Refractive index	Abbe number
						S1	First lens	4.6702	1.300	1.537	55.7
S2		-42.9801	0.391
						S3	Second lens	18.0341	0.631	1.646	23.5
S4		4.3778	1.000
						S5	First prism	Infinity(s)	2.200	1.519	64.2
S6		Infinity(s)	2.200	1.519	64.2
						S7		Infinity(s)	2.200
S8	Third lens	5.5645	0.700	1.537	55.7
						S9		14.1348	1.000
S10	Second prism	Infinity(s)	3.500	1.519	64.2
						S11		Infinity(s)	2.500	1.519	64.2
S12		Infinity(s)	1.250	1.519	64.2
						S11		Infinity(s)	0.500
S13	Light filter	Infinity(s)	0.210	1.519	64.2
						S14		Infinity(s)	0.479
S15	Image plane	Infinity(s)	0.000

TABLE 8

Noodle number	S1	S2	S3	S4	S8	S9
							k
	0	0	3.81E+01	4.58E-01	0	-2.0E+00
							A	0	0	1.55E-02	9.45E-03	0	6.0E-04
B
		0	0	7.11E-04	1.42E-03	0	-2.8E-05
C
		0	0	5.93E-04	2.08E-04	0	5.4E-05
D
		0	0	1.58E-04	3.24E-04	0	-3.4E-06
E								0	0	1.12E-04	1.02E-04	0	-2.7E-06
	F
		0	0	-1.92E-05	-2.22E-05	0	-1.6E-07
	G
		0	0	1.03E-04	1.54E-04	0	1.3E-07
	H
		0	0	0	0	0	3.0E-08
	J
		0	0	0	0	0	-8.4E-09

Next, an imaging lens system according to a fifth exemplary embodiment is described with reference to fig. 13.

The imaging lens system 500 according to the present exemplary embodiment may include a first lens group LG1, a first prism P1, a second lens group LG2, and a second prism P2. However, the components of the imaging lens system 500 are not limited to the above-described members. For example, the imaging lens system 500 may further include a filter IF and an imaging plane IP. The first lens group LG1, the first prism P1, the second lens group LG2, and the second prism P2 may be arranged in order from the object side. For example, the first lens group LG1 may be disposed on the object side of the first prism P1, and the second lens group LG2 may be disposed between the first prism P1 and the second prism P2.

Next, the above components are described in order.

The first lens group LG1 may include a plurality of lenses. For example, the first lens group LG1 may include a first lens 510 and a second lens 520 arranged in order from the object side. The first lens 510 and the second lens 520 may be disposed at a predetermined interval. For example, the image side of the first lens 510 may not be in contact with the object side of the second lens 520. However, the first lens 510 and the second lens 520 may not necessarily be disposed not to contact each other. For example, the image side of first lens 510 may be in contact with the object side of second lens 520.

The second lens group LG2 may include one or more lenses. For example, the second lens group LG2 may include the third lens 530. However, the lenses included in the second lens group LG2 are not limited to the third lens 530.

Next, characteristics of the first to third lenses 510 to 530 included in the first lens group LG1 and the second lens group LG2 are described.

The first lens 510 may have optical power. For example, the first lens 510 may have a positive refractive power. The first lens 510 may have a convex object side and a convex image side. The first lens 510 may have a spherical surface. For example, both surfaces of the first lens 510 may be spherical. The second lens 520 may have optical power. For example, the second lens 520 may have a negative refractive power. Second lens 520 may have a convex object side surface and a concave image side surface. The second lens 520 may have an aspherical surface. For example, both surfaces of the second lens 520 may be aspherical. The third lens 530 may have optical power. For example, the third lens 530 may have a negative refractive power. The third lens 530 may have a convex object side surface and a concave image side surface. The third lens 530 may have a spherical surface and an aspherical surface. For example, the object side surface of the third lens 530 may be spherical, and the image side surface of the third lens 530 may be aspherical.

Next, the first prism P1 and the second prism P2 as the optical path folding members are described. For reference, a prism described below is one type of the optical path folding member described in claims, and may be changed to another member.

The first and second prisms P1 and P2 may be disposed such that light incident through the first to third lenses 510 to 530 is imaged on the imaging plane IP. For example, the first prism P1 and the second prism P2 may be sequentially disposed along the optical path between the second lens 520 and the imaging plane IP.

The first prism P1 may include a reflective surface. For example, the first prism P1 may include a first reflecting surface S6. The first reflecting surface S6 can achieve total reflection. For example, the first incident angle θ 1 of the first reflective surface S6 may be greater than the critical angle of the first reflective surface S6. In more detail, the first incident angle θ 1 may be 45 degrees greater than 41.2 degrees (i.e., a critical angle of the first reflection surface S6). The first prism P1 configured as described above may reflect light incident from the second lens 520 to the third lens 530 and the second prism P2.

The second reflecting surface S11 and the third reflecting surface S12 may form an acute angle. For example, the angle θ P2 between the second reflecting surface S11 and the third reflecting surface S12 may be 16 degrees to 32 degrees. The second and third reflection surfaces S11 and S12 may have a predetermined angle with the incident surface S10 of the second prism P2. For example, an angle between the second reflection surface S11 and the incidence surface S10 of the second prism P2 may be 58 to 74 degrees, and an angle between the third reflection surface S12 and the incidence surface S10 of the second prism P2 may be about 90 degrees.

One surface of the second prism P2 can realize both reflection and projection. For example, the second reflection surface S11 of the second prism P2 may transmit light incident from the third reflection surface S12 while reflecting light incident through the incident surface S10 to the third reflection surface S12.

The first prism P1 and the second prism P2 configured as described above can miniaturize and integrate the imaging lens system 500 by folding the optical path connected from the object side to the imaging plane IP. For example, the first prism P1 may fold an optical path extending along the first optical axis C1 in a direction of a second optical axis C2 intersecting the first optical axis C1, thereby reducing a length of the imaging lens system 500 in the direction of the first optical axis C1. In another example, the second prism P2 may fold the optical path extending along the second optical axis C2 two or more times by total reflection and mirror reflection, thereby reducing the length of the imaging lens system 500 in the direction of the second optical axis C2.

The imaging lens system 500 configured as above can exhibit the aberration characteristics shown in fig. 14. Table 9 and table 10 show lens characteristics and aspherical surface values of the imaging lens system according to the present exemplary embodiment, respectively.

TABLE 9

Noodle numbering	Component part	Radius of curvature	Thickness/distance	Refractive index	Abbe number
						S1	First lens	5.5237	1.000	1.537	55.7
S2		-25.1115	0.050
						S3	Second lens	13.5896	0.400	1.646	23.5
S4		7.0152	0.800
						S5	First prism	Infinity(s)	1.600	1.519	64.2
S6		Infinity(s)	1.600	1.519	64.2
						S7		Infinity(s)	2.500
S8	Third lens	16.0727	0.400	1.537	55.7
						S9		10.7448	1.500
S10	Second prism	Infinity(s)	3.000	1.519	64.2
						S11		Infinity(s)	2.000	1.519	64.2
S12		Infinity(s)	1.000	1.519	64.2
						S11		Infinity(s)	0.500
S13	Light filter	Infinity(s)	0.210	1.519	64.2
						S14		Infinity(s)	0.236
S15	Image plane	Infinity(s)	0.066

Watch 10

Noodle numbering	S1	S2	S3	S4	S8	S9
							k
	0	0	3.26E+01	1.15E+00	0	2.0E+01
							A	0	0	1.37E-02	5.12E-03	0	2.1E-03
B
		0	0	-8.93E-04	1.42E-03	0	3.0E-04
C
		0	0	7.69E-04	5.53E-04	0	1.0E-04
D
		0	0	7.84E-04	7.76E-04	0	5.2E-05
E
		0	0	-1.57E-04	6.40E-05	0	3.8E-05
F
		0	0	-7.69E-06	4.97E-05	0	2.2E-05
G
		0	0	-8.42E-06	-2.76E-05	0	1.6E-06
H
		0	0	0	0	0	0
J								0	0	0	0	0	0

Next, an imaging lens system according to a sixth exemplary embodiment is described with reference to fig. 15.

The imaging lens system 600 according to the present exemplary embodiment may include a first lens group LG1, a first prism P1, a second lens group LG2, and a second prism P2. However, the components of the imaging lens system 600 are not limited to the above-described members. For example, the imaging lens system 600 may further include a filter IF and an imaging plane IP. The first lens group LG1, the first prism P1, the second lens group LG2, and the second prism P2 may be arranged in order from the object side. For example, the first lens group LG1 may be disposed on the object side of the first prism P1, and the second lens group LG2 may be disposed between the first prism P1 and the second prism P2.

Next, the above components are described in order.

The first lens group LG1 may include a plurality of lenses. For example, the first lens group LG1 may include a first lens 610 and a second lens 620 sequentially disposed from the object side. The first lens 610 and the second lens 620 may be disposed at a predetermined interval. For example, the image side of the first lens 610 may not be in contact with the object side of the second lens 620. However, the first lens 610 and the second lens 620 may not necessarily be disposed not to contact each other. For example, the image side of the first lens 610 may be in contact with the object side of the second lens 620.

The second lens group LG2 may include a plurality of lenses. For example, the second lens group LG2 may include a third lens 630 and a fourth lens 640 disposed in order from the object side. The third lens 630 and the fourth lens 640 may be disposed at a predetermined interval. For example, the image side surface of the third lens 630 may not be in contact with the object side surface of the fourth lens 640. However, the third lens 630 and the fourth lens 640 may not necessarily be disposed not to contact each other. For example, the image side surface of the third lens 630 may be in contact with the object side surface of the fourth lens 640.

Next, characteristics of the first lens 610 to the fourth lens 640 included in the first lens group LG1 and the second lens group LG2 are described.

The first lens 610 may have optical power. For example, the first lens 610 may have a positive refractive power. The first lens 610 may have a convex object side and a convex image side. The first lens 610 may have a spherical surface. For example, both surfaces of the first lens 610 may be spherical. Second lens 620 may have optical power. For example, the second lens 620 may have a negative refractive power. Second lens 620 may have a convex object side surface and a concave image side surface. The second lens 620 may have an aspherical surface. For example, both surfaces of second lens 620 may be aspherical. The third lens 630 may have an optical power. For example, the third lens 630 may have a negative refractive power. The third lens 630 may have a concave object side surface and a concave image side surface. The third lens 630 may have a spherical surface. For example, both surfaces of the third lens 630 may be spherical. The fourth lens 640 may have optical power. For example, the fourth lens 640 may have a negative refractive power. The fourth lens 640 may have a convex object side surface and a concave image side surface. The fourth lens 640 may have an aspherical surface. For example, both surfaces of the fourth lens 640 may be aspherical.

The first prism P1 and the second prism P2 may be disposed such that light incident through the first lens 610 to the fourth lens 640 is imaged on the imaging plane IP. For example, the first prism P1 and the second prism P2 may be sequentially disposed along the optical path between the second lens 620 and the imaging plane IP.

The first prism P1 may include a reflective surface. For example, the first prism P1 may include a first reflecting surface S6. The first reflecting surface S6 can achieve total reflection. For example, the first incident angle θ 1 of the first reflective surface S6 may be greater than the critical angle of the first reflective surface S6. In more detail, the first incident angle θ 1 may be 45 degrees greater than 41.2 degrees (i.e., a critical angle of the first reflection surface S6). The first prism P1 configured as described above may reflect light incident from the second lens 620 to the second prism P2.

The second prism P2 may have a triangular cross-section. For example, a section of the second prism P2 cut in the optical path direction may have a right-angled triangle shape. The second prism P2 may include a plurality of reflective surfaces. For example, the second prism P2 may include a second reflection surface S13 and a third reflection surface S14.

The second prism P2 can realize multiple internal reflections. For example, light incident through the incident surface S12 of the second prism P2 may be reflected by the second reflecting surface S13 and then reflected again by the third reflecting surface S14.

The first, second, and third reflecting surfaces S6, S13, and S14 of the first and second prisms P1 and P2 may have a predetermined dimensional relationship therebetween. For example, the first incident angle θ 1 may be smaller than the second incident angle θ 2, and the third incident angle θ 3 may be smaller than the first incident angle θ 1.

The first prism P1 and the second prism P2 configured as described above can miniaturize and integrate the imaging lens system 600 by folding the optical path connected from the object side to the imaging plane IP. For example, the first prism P1 may fold an optical path extending along the first optical axis C1 in a direction of a second optical axis C2 intersecting the first optical axis C1, thereby reducing a length of the imaging lens system 600 in the direction of the first optical axis C1. In another example, the second prism P2 may fold the optical path extending along the second optical axis C2 by total reflection and mirror reflection two or more times, thereby reducing the length of the imaging lens system 600 in the direction of the second optical axis C2.

The imaging lens system 600 configured as above can show the aberration characteristics shown in fig. 16. Table 11 and table 12 show lens characteristics and aspherical values of the imaging lens system according to the present exemplary embodiment, respectively.

TABLE 11

Noodle number	Component part	Radius of curvature	Thickness/distance	Refractive index	Abbe number
						S1	First lens	5.2750	0.900	1.537	55.7
S2		-35.6289	0.050
						S3	Second lens	13.2037	0.500	1.669	20.3
S4		9.4598	0.800
						S5	First prism	Infinity(s)	1.600	1.723	29.5
S6		Infinity(s)	1.600	1.723	29.5
						S7		Infinity(s)	1.500
S8	Third lens	-17.5264	0.882	1.669	20.3
						S9		17.8445	0.080
S10	Fourth lens	11.2450	1.505	1.537	55.7
						S11		8.3425	0.800
S12	Second prism	Infinity(s)	3.500	1.723	29.5
						S13		Infinity(s)	2.000	1.723	29.5
S14		Infinity(s)	1.000	1.723	29.5
						S13		Infinity(s)	0.200
S15	Light filter	Infinity(s)	0.210	1.519	64.2
						S16		Infinity(s)	0.148
S17	Image plane	Infinity(s)	0.000

TABLE 12

Next, an imaging lens system according to a seventh exemplary embodiment is described with reference to fig. 17.

The imaging lens system 700 according to the present exemplary embodiment may include a first lens group LG1, a first prism P1, a second lens group LG2, and a second prism P2. However, the components of the imaging lens system 700 are not limited to the above-described members. For example, the imaging lens system 700 may further include a filter IF and an imaging plane IP. The first lens group LG1, the first prism P1, the second lens group LG2, and the second prism P2 may be arranged in order from the object side. For example, the first lens group LG1 may be disposed on the object side of the first prism P1, and the second lens group LG2 may be disposed between the first prism P1 and the second prism P2.

Next, the above components are described in order.

The first lens group LG1 may include a plurality of lenses. For example, the first lens group LG1 may include a first lens 710 and a second lens 720 sequentially disposed from the object side. The first lens 710 and the second lens 720 may be disposed at a predetermined interval. For example, the image side surface of the first lens 710 may not be in contact with the object side surface of the second lens 720. However, the first lens 710 and the second lens 720 may not necessarily be disposed not to contact each other. For example, the image side surface of the first lens 710 may be in contact with the object side surface of the second lens 720.

The second lens group LG2 may include a plurality of lenses. For example, the second lens group LG2 may include a third lens 730 and a fourth lens 740 disposed in order from the object side. The third lens 730 and the fourth lens 740 may be disposed at a predetermined interval. For example, the image side surface of the third lens 730 may not be in contact with the object side surface of the fourth lens 740. However, the third lens 730 and the fourth lens 740 may not necessarily be disposed not to contact each other. For example, the image side surface of the third lens 730 may be in contact with the object side surface of the fourth lens 740.

Next, characteristics of the first lens 710 to the fourth lens 740 included in the first lens group LG1 and the second lens group LG2 are described.

The first lens 710 may have optical power. For example, the first lens 710 may have a positive refractive power. The first lens 710 may have a convex object side and a convex image side. The first lens 710 may have an aspheric surface. For example, both surfaces of the first lens 710 may be aspheric. The second lens 720 may have optical power. For example, the second lens 720 may have a negative refractive power. The second lens 720 may have a convex object side surface and a concave image side surface. The second lens 720 may have an aspherical surface. For example, both surfaces of the second lens 720 may be aspheric. The third lens 730 may have an optical power. For example, the third lens 730 may have a negative refractive power. The third lens 730 may have a convex object side surface and a concave image side surface. The third lens 730 may have a spherical surface. For example, both surfaces of the third lens 730 may be spherical. Fourth lens 740 may have optical power. For example, the fourth lens 740 may have a negative refractive power. The fourth lens 740 may have a convex object side surface and a concave image side surface. The fourth lens 740 may have an aspheric surface. For example, both surfaces of the fourth lens 740 may be aspherical.

The first and second prisms P1 and P2 may be disposed such that light incident through the first through fourth lenses 710 through 740 is imaged on the imaging plane IP. For example, the first prism P1 and the second prism P2 may be sequentially disposed along the optical path between the second lens 720 and the imaging plane IP.

The first prism P1 may have a triangular cross-section. For example, a section of the first prism P1 cut in the optical path direction may have a right-angled triangle shape. The incident surface S5 of the first prism P1 and the projection surface S7 of the first prism P1 may form a substantially right angle. For example, the incident surface S5 of the first prism P1 and the projection surface S7 of the first prism P1 may be formed in portions other than the hypotenuse in the sectional shape of the right triangle, respectively.

The first prism P1 may include a reflective surface. For example, the first prism P1 may include a first reflecting surface S6. The first reflecting surface S6 can achieve total reflection. For example, the first incident angle θ 1 of the first reflective surface S6 may be greater than the critical angle of the first reflective surface S6. In more detail, the first incident angle θ 1 may be 45 degrees greater than 41.2 degrees (i.e., a critical angle of the first reflection surface S6). The first prism P1 configured as described above may reflect light incident from the second lens 720 to the second prism P2.

The first prism P1 and the second prism P2 configured as described above can miniaturize and integrate the imaging lens system 700 by folding the optical path connected from the object side to the imaging plane IP. For example, the first prism P1 may fold an optical path extending along the first optical axis C1 in a direction of a second optical axis C2 intersecting the first optical axis C1, thereby reducing the length of the imaging lens system 700 in the direction of the first optical axis C1. In another example, the second prism P2 may fold the optical path extending along the second optical axis C2 two or more times by total reflection and mirror reflection, thereby reducing the length of the imaging lens system 700 in the direction of the second optical axis C2.

The imaging lens system 700 configured as above can exhibit the aberration characteristics shown in fig. 18. Table 13 and table 14 show lens characteristics and aspherical values of the imaging lens system according to the present exemplary embodiment, respectively.

Watch 13

TABLE 14

Noodle numbering

S1

S2

S3

S4

S8

S9

S10

S11

k

3.12E-01

-9.90E+01

2.82E+01

-6.68E-01

-9.35E+01

3.72E+00

3.18E+01

-9.89E+00

A

2.00E-05

-6.28E-03

2.16E-02

1.24E-02

0

-3.75E-03

-3.70E-03

B

2.18E-04

1.53E-02

-1.01E-03

3.27E-04

0

-3.47E-04

-5.58E-04

C

-1.14E-04

-1.48E-02

1.87E-04

1.51E-04

0

-1.09E-04

-2.32E-04

D

3.27E-05

7.97E-03

6.33E-04

-5.14E-05

0

-3.87E-05

-1.09E-04

E

-7.09E-06

-2.60E-03

-2.31E-04

8.40E-04

0

-2.21E-05

-6.50E-05

F

5.71E-07

5.20E-04

-2.65E-04

-8.91E-04

0

-8.55E-06

-4.15E-05

G

-4.16E-08

-6.19E-05

-2.90E-05

-2.81E-04

0

-1.61E-06

-2.84E-05

H

1.03E-09

4.04E-06

0

J

1.54E-09

-1.16E-07

0

Next, an imaging lens system according to an eighth exemplary embodiment is described with reference to fig. 19.

The imaging lens system 800 according to the present exemplary embodiment may include a first lens group LG1, a first prism P1, a second lens group LG2, and a second prism P2. However, the components of the imaging lens system 800 are not limited to the above-described members. For example, the imaging lens system 800 may further include a filter IF and an imaging plane IP. The first lens group LG1, the first prism P1, the second lens group LG2, and the second prism P2 may be arranged in order from the object side. For example, the first lens group LG1 may be disposed on the object side of the first prism P1, and the second lens group LG2 may be disposed between the first prism P1 and the second prism P2.

Next, the above components are described in order.

The first lens group LG1 may include a plurality of lenses. For example, the first lens group LG1 may include a first lens 810 and a second lens 820 disposed in order from the object side. The first lens 810 and the second lens 820 may be disposed at a predetermined interval. For example, the image side surface of the first lens 810 may not be in contact with the object side surface of the second lens 820. However, the first lens 810 and the second lens 820 may not necessarily be disposed not to contact each other. For example, the image side of first lens 810 may be in contact with the object side of second lens 820.

The second lens group LG2 may include a plurality of lenses. For example, the second lens group LG2 may include a third lens 830 and a fourth lens 840 arranged in order from the object side. The third lens 830 and the fourth lens 840 may be disposed at a predetermined interval. For example, the image side surface of the third lens 830 may not be in contact with the object side surface of the fourth lens 840. However, the third lens 830 and the fourth lens 840 may not necessarily be disposed not to contact each other. For example, the image side surface of the third lens 830 may be in contact with the object side surface of the fourth lens 840.

Next, characteristics of the first lens 810 to the fourth lens 840 included in the first lens group LG1 and the second lens group LG2 are described.

First lens 810 may have an optical power. For example, first lens 810 may have a positive refractive power. First lens 810 may have a convex object side and a convex image side. The first lens 810 may have a spherical surface and an aspherical surface. For example, the object side surface of first lens 810 may be spherical, and the image side surface of first lens 810 may be aspherical. The second lens 820 may have an optical power. For example, the second lens 820 may have a negative refractive power. The second lens 820 may have a convex object side surface and a concave image side surface. The second lens 820 may have an aspherical surface. For example, both surfaces of the second lens 820 may be aspheric. The third lens 830 may have an optical power. For example, the third lens 830 may have a negative refractive power. The third lens 830 may have a convex object side surface and a concave image side surface. The third lens 830 may have an aspheric surface. For example, both surfaces of the third lens 830 may be aspherical. The fourth lens 840 may have optical power. For example, the fourth lens 840 may have a positive refractive power. The fourth lens 840 may have a convex object side surface and a concave image side surface. The fourth lens 840 may have an aspherical surface. For example, both surfaces of the fourth lens 840 may be aspheric.

Next, the first prism P1 and the second prism P2 as the optical path folding member are described. For reference, the prism described below is one type of the optical path folding member described in the claims, and may be changed to another type.

The first and second prisms P1 and P2 may be disposed such that light incident through the first to fourth lenses 810 to 840 is imaged on the imaging plane IP. For example, the first prism P1 and the second prism P2 may be sequentially disposed along the optical path between the second lens 820 and the imaging plane IP.

The first prism P1 may include a reflective surface. For example, the first prism P1 may include a first reflecting surface S6. The first reflecting surface S6 can achieve total reflection. For example, the first incident angle θ 1 of the first reflective surface S6 may be greater than the critical angle of the first reflective surface S6. In more detail, the first incident angle θ 1 may be 45 degrees greater than 41.2 degrees (i.e., a critical angle of the first reflection surface S6). The first prism P1 configured as described above may reflect light incident from the second lens 820 to the second prism P2.

The first prism P1 and the second prism P2 configured as described above can miniaturize and integrate the imaging lens system 800 by folding the optical path connected from the object side to the imaging plane IP. For example, the first prism P1 may fold an optical path extending along the first optical axis C1 in a direction of a second optical axis C2 intersecting the first optical axis C1, thereby reducing a length of the imaging lens system 800 in the direction of the first optical axis C1. In another example, the second prism P2 may fold the optical path extending along the second optical axis C2 two or more times by total reflection and mirror reflection, thereby reducing the length of the imaging lens system 800 in the direction of the second optical axis C2.

The imaging lens system 800 configured as above can exhibit the aberration characteristics shown in fig. 20. Table 15 and table 16 show lens characteristics and aspherical surface values of the imaging lens system according to the present exemplary embodiment, respectively.

Watch 15

TABLE 16

Noodle numbering

S1

S2

S3

S4

S8

S9

S10

S11

k

3.21E-01

-9.90E+01

2.80E+01

9.60E-02

9.35E+01

-3.30E+00

-3.16E+01

4.27E+01

A

0

-6.00E-03

2.00E-03

-1.00E-03

0

6.00E-03

2.00E-02

B

0

1.50E-02

-2.00E-03

-2.30E-02

0

-6.90E-02

-1.09E-01

C

0

-1.50E-02

1.20E-02

4.60E-02

0

1.76E-01

2.79E-01

D

0

8.00E-03

-1.70E-02

-5.20E-02

0

-2.97E-01

-4.49E-01

E

0

-3.00E-03

1.20E-02

3.60E-02

0

3.24E-01

4.58E-01

F

0

1.00E-03

-5.00E-03

-1.50E-02

0

-2.24E-01

-2.96E-01

G

0

1.00E-03

4.00E-03

0

9.40E-02

1.17E-01

H

0

-1.00E-03

-6.81E-07

-1.04E-06

-2.20E-02

-2.57E-02

J

0

-2.49E-07

-4.07E-07

2.16E-03

2.39E-03

Table 17 and table 18 show optical characteristic values and conditional expression values of the imaging lens systems according to the above-described first to eighth exemplary embodiments, respectively.

TABLE 17

Watch 18

Next, an electronic apparatus according to the present disclosure is described.

An electronic device according to the present disclosure may include an imaging lens system according to an exemplary embodiment. For example, the electronic device may include one or more of the imaging lens systems according to the first to eighth exemplary embodiments. As a specific example, the electronic device may include the imaging lens system 100 according to the first exemplary embodiment. In another example, the electronic device may include the imaging lens system 100 according to the first exemplary embodiment and the imaging lens system 800 according to the eighth exemplary embodiment. In another example, the electronic device may include two imaging lens systems 200 according to the second exemplary embodiment and the imaging lens system 600 according to the sixth exemplary embodiment. However, the imaging lens system that may be located in the electronic device according to the exemplary embodiment is not limited to the above type.

Next, an electronic apparatus according to an exemplary embodiment is described with reference to fig. 21 and 22.

The electronic device 1000 according to an exemplary embodiment may be a portable terminal. For example, the electronic device 1000 may be a smartphone. However, the type of the electronic device 1000 is not limited to a smartphone. For example, an electronic device according to another exemplary embodiment may be a laptop computer.

The electronic device 1000 may include one or

more camera modules

10 and 20. For example, two

camera modules

10 and 20 may be installed in the electronic device 1000. The first camera module 10 and the second camera module 20 may be arranged to image the object in the same direction. For example, the first and

second camera modules

10 and 20 may be mounted on one surface of the electronic device 1000 so as to be parallel to each other.

At least one of the first and

second camera modules

10 and 20 may include the imaging lens system according to the first to eighth exemplary embodiments. For example, the first camera module 10 may include the imaging lens system 100 according to the first exemplary embodiment.

The first camera module 10 can realize high resolution. In detail, as shown in fig. 22, the first camera module 10 may have an image sensor IS diagonally disposed with respect to the thickness direction of the electronic apparatus 1000, and thus have a large image sensor IS required to achieve high resolution. In more detail, the image sensor IS may be disposed at an inclination of 18 to 30 degrees with respect to the front of the electronic device 1000 or a display device (e.g., a display panel).

The electronic apparatus 1000 configured as described above can mount an image sensor larger than the internal space (particularly, the thickness thereof) and a camera module including the image sensor, and thus can improve the performance of the camera module and reduce the thickness of the electronic apparatus at the same time.

As described above, the present disclosure may provide an imaging lens system that may be mounted in a small-sized terminal or a thin-sized terminal.

Further, the present disclosure may provide a camera module having a telephoto imaging lens system.

While specific exemplary embodiments have been shown and described above, it will be apparent after understanding 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 to be included in the present disclosure.

Claims

1. An imaging lens system comprising:

an optical path folding member including a frontmost reflection surface disposed closest to an object side, a rearmost reflection surface disposed closest to an imaging plane, and a rear reflection surface disposed to form an acute angle with the rearmost reflection surface and configured to reflect light reflected by the rearmost reflection surface to the imaging plane; and

a first lens group disposed on an object side of the frontmost reflective surface or on an image side of the frontmost reflective surface,

wherein an angle between a first virtual plane including the frontmost reflective surface and a second virtual plane including the rearmost reflective surface is 15 to 27 degrees, an

Wherein the first lens group includes at least one lens having an aspherical surface.

2. The imaging lens system according to claim 1, wherein the first lens group includes a first lens and a second lens which are arranged in order from the object side.

3. The imaging lens system of claim 2, wherein the first lens has a positive optical power and the second lens has a negative optical power.

4. The imaging lens system according to claim 2, wherein 30< -v1-V2, where V1 is the abbe number of the first lens and V2 is the abbe number of the second lens.

5. The imaging lens system of claim 1, wherein an angle between the final reflective surface and the rear reflective surface is 18 to 30 degrees.

6. The imaging lens system according to claim 1, wherein the optical path folding member further includes:

a first optical path folding member including the frontmost reflective surface; and

a second light path folding member including the rear reflection surface and the final reflection surface.

7. The imaging lens system of claim 6, further comprising a second lens group disposed on the object side or the image side of the frontmost reflective surface on which the first lens group is not disposed.

8. The imaging lens system of claim 7, wherein the second lens group comprises one or more lenses.

9. The imaging lens system of claim 1, wherein BFL/TTL <0.9, wherein BFL is a distance from an image side surface of a last lens of the first lens group to the imaging surface, and TTL is a distance from an object side surface of a foremost lens of the first lens group to the imaging surface.

10. A camera module, comprising:

the imaging lens system according to any one of claims 1 to 9; and

an image sensor is provided with a plurality of image sensors,

wherein the imaging surface is disposed on the image sensor.

11. An electronic device comprising the camera module of claim 10, wherein the image sensor is disposed diagonally with respect to a thickness direction of the electronic device.

12. An imaging lens system comprising:

a first optical path folding member having one reflection surface and having a right-angled triangle sectional shape;

a second optical path folding member having two or more reflection surfaces and having a sectional shape of a right triangle;

a lens unit disposed to face an incident surface or an exit surface of the first optical path folding member; and

an imaging surface disposed to face the total reflection surface of the second optical path folding member,

wherein the first optical path folding member, the second optical path folding member, and the imaging surface are sequentially arranged along an optical axis of the lens unit, an

Wherein the lens unit includes at least one lens having an aspherical surface.

13. The imaging lens system according to claim 12, wherein the second optical path folding member includes:

a first reflecting surface that reflects the light emitted from the first optical path folding member; and

a second reflective surface to reflect the light reflected from the first reflective surface to the first reflective surface.

14. The imaging lens system of claim 13, wherein an angle between the first and second reflective surfaces is 16 to 32 degrees.

15. The imaging lens system according to claim 12, wherein a maximum length of the incident surface of the first light path folding member is smaller than a maximum length of the exit surface of the second light path folding member.

16. The imaging lens system according to claim 12, wherein a distance from the exit surface of the first optical path folding member to an entrance surface of the second optical path folding member is larger than a distance from an exit surface of the second optical path folding member to the imaging plane.

17. The imaging lens system according to claim 12, wherein the lens unit includes a first lens group provided on an object side of the first optical path folding member.

18. The imaging lens system according to claim 12, wherein the lens unit includes a first lens group provided between the first optical path folding member and the second optical path folding member.

19. The imaging lens system of claim 12, wherein the lens unit comprises:

a first lens group disposed on an object side of the first optical path folding member; and

a second lens group disposed between the first optical path folding member and the second optical path folding member.

20. Camera module comprising an imaging lens system according to any one of claims 12 to 19.

21. Electronic device comprising the camera module of claim 20,

wherein the imaging surface is disposed on an image sensor, an

Wherein the image sensor is disposed diagonally with respect to a thickness direction of the electronic device.

22. An imaging lens system comprising:

an optical path folding member including a first reflection surface, a second reflection surface, and a third reflection surface configured to sequentially reflect light incident from an object side; and

a first lens group disposed on the object side or the image side of the first reflection surface,

wherein a first incident angle of the first reflective surface is less than a second incident angle of the second reflective surface and a third incident angle of the third reflective surface is less than the first incident angle of the first reflective surface, an

23. The imaging lens system of claim 22, wherein the first and second incident angles are greater than a critical angle of the first and second reflective surfaces, respectively, and the third incident angle is less than a critical angle of the third reflective surface.

24. The imaging lens system of claim 22, wherein the first and second incident angles are each greater than 36 degrees and less than 90 degrees.

25. The imaging lens system of claim 22, wherein the third angle of incidence is greater than 28 degrees and less than 56 degrees.

26. The imaging lens system of claim 22, wherein an imaging surface is disposed facing the second reflective surface.

27. An electronic device, comprising:

a camera module, comprising: the imaging lens system of any one of claims 22 to 26; and an image sensor including an imaging surface disposed to face the second reflection surface,

28. An imaging lens system comprising:

a first lens having a positive refractive power;

a second lens having a negative refractive power, a convex object-side surface and a concave image-side surface;

a third lens having a refractive power and a concave image side surface; and

a first reflection surface, a second reflection surface, and a third reflection surface arranged in this order from the object side along the optical axis,

wherein the first lens, the second lens, the third lens, the second reflective surface, and the third reflective surface are arranged in order from the object side along the optical axis, an

Wherein at least one of the first lens to the third lens has an aspherical surface.

29. The imaging lens system of claim 28, wherein an angle between a first virtual plane including the first reflective surface and a second virtual plane including the second reflective surface is 15 to 27 degrees.

30. The imaging lens system of claim 28, further comprising an imaging plane disposed along the optical axis and parallel to a virtual plane comprising the second reflective surface.

31. The imaging lens system of claim 28, wherein a first incident angle of the first reflective surface is less than a second incident angle of the second reflective surface, and a third incident angle of the third reflective surface is less than the first incident angle of the first reflective surface.

32. The imaging lens system of claim 28, further comprising a fourth lens having an optical power and disposed between the first and second reflective surfaces along the optical axis.

33. The imaging lens system of claim 28, further comprising a fourth reflective surface and a fifth reflective surface disposed along the optical axis between the first reflective surface and the second reflective surface.

34. The imaging lens system of claim 28, wherein the optical axis extends between the second and third reflective surfaces a plurality of times.

35. The imaging lens system of claim 28, wherein the third lens is disposed between the first and second reflective surfaces along the optical axis.

36. An electronic device, comprising:

a camera module comprising the imaging lens system of any one of claims 28 to 35; and an image sensor including an imaging surface disposed to face the second reflection surface,