Optical imaging system, camera module and mobile terminal device

Abstract

The present disclosure relates to an optical imaging system, a camera module, and a mobile terminal device. Among them, the optical imaging system includes a plurality of lenses arranged along the optical axis from the object side of the optical imaging system towards the imaging surface of the optical imaging system. The lenses are separated from each other by corresponding air gaps along the optical axis between the lenses. The lenses include a first lens closest to the object side of the optical imaging system. The condition expression 1.5mm < Gmax,TL < 12.0mm, and 0.15 < R1 / f is satisfied, where Gmax is the maximum air gap among all the air gaps along the optical axis, TL is the length of the optical imaging system along the optical axis from the object side surface of the first lens to the imaging surface, R1 is the radius of curvature of the object side surface of the first lens, and f is the focal length of the optical imaging system.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of priority of Korean Patent Application No. 10 - 2020 - 0123436, filed with the Korean Intellectual Property Office on September 24, 2020, the entire disclosure of which is incorporated herein by reference for all purposes. Technical field

[0003] This application relates to an optical imaging system having a variable length along an optical axis. Background art

[0004] A mobile terminal device may include a camera module. For example, a mobile terminal device may include one or more camera modules. The camera module has a predetermined size. For example, the camera module has a size corresponding to the total lens length (TL) between a lens closest to the object side of the camera module and the imaging surface (or image sensor) of the camera module. The size of the camera module (i.e., TL) increases as the resolution or other performance of the camera module improves. The increase in the size of the camera module may cause a change in the appearance of the mobile terminal device. For example, the camera module may protrude outward from the surface of the mobile terminal device, providing an unpleasant user experience. In addition, the increase in the size of the camera module may lead to frequent damage to the camera module. For example, since most of the camera module is exposed outside the mobile terminal device, the camera module may be easily damaged by external impacts. Summary of the invention

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

[0006] In one general aspect, an optical imaging system includes a plurality of lenses sequentially arranged along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging surface of the optical imaging system, the plurality of lenses being separated from each other by respective air gaps between the plurality of lenses along the optical axis, wherein the plurality of lenses includes a first lens closest to the object side of all the lenses of the optical imaging system, and satisfies the conditional expression 1.5mm < Gmax,TL < 12.0mm, and 0.15 < R1 / f, where Gmax is the maximum air gap among all the air gaps along the optical axis between the plurality of lenses, TL is the length of the optical imaging system along the optical axis from the object surface of the first lens to the imaging surface, R1 is the radius of curvature of the object surface of the first lens, and f is the focal length of the optical imaging system.

[0007] The first lens may have a positive refractive power.

[0008] The first lens may have a concave image side.

[0009] The plurality of lenses may further include a second lens, a third lens, a fourth lens, and a fifth lens that are sequentially arranged in ascending order along the optical axis on the image side of the first lens toward the imaging surface.

[0010] The conditional expression 0.001 < D12 / f < 0.04 may be satisfied, where D12 is the air gap between the first lens and the second lens along the optical axis and is equal to the distance along the optical axis from the image side of the first lens to the object side of the second lens.

[0011] The conditional expression -3.0 < f / f2 + f / f3 may be satisfied, where f2 is the focal length of the second lens and f3 is the focal length of the third lens.

[0012] The conditional expression 3.2 < Nd2 + Nd3 may be satisfied, where Nd2 is the refractive index of the second lens and Nd3 is the refractive index of the third lens.

[0013] The conditional expression 0.6 < TL / f < 1.3 may be satisfied.

[0014] The plurality of lenses may further include the last lens closest to the imaging surface among all the lenses of the optical imaging system, and the conditional expression 0.12 < BFL / f < 0.26 may be satisfied, where BFL is the length along the optical axis from the image side of the last lens to the imaging surface.

[0015] In another general aspect, an optical imaging system includes a first lens group and a second lens group. The first lens group includes a first lens, and the first lens is arranged to be closest to the object side of the optical imaging system among all the lenses of the optical imaging system. The second lens group is arranged between the first lens group and the imaging surface of the optical imaging system. The first lens group is configured to be movable to increase and decrease the distance between the first lens group and the second lens group, and the ratio TLs / TL of the length TLs to the length TL is greater than 0.70 and less than 0.79. The length TLs is the length along the optical axis of the optical imaging system from the object side of the first lens to the imaging surface in a state where the first lens group has been moved to decrease the distance between the first lens group and the second lens group, and the length TL is the length along the optical axis of the optical imaging system from the object side of the first lens to the imaging surface in a state where the first lens group has been moved to increase the distance between the first lens group and the second lens group.

[0016] The first lens may have a positive refractive power.

[0017] An air gap between the first lens group and the second lens group along the optical axis may be greater than 1.9 mm and less than 2.8 mm, and may be a maximum air gap among all air gaps between lenses in the optical imaging system along the optical axis.

[0018] The optical imaging system may further include a third lens group disposed between the second lens group and the imaging surface.

[0019] An air gap between the second lens group and the third lens group along the optical axis may be greater than 2.0 mm and less than 2.8 mm, and may be a maximum air gap among all air gaps between lenses in the optical imaging system along the optical axis.

[0020] The air gap between the first lens group and the second lens group along the optical axis may be smaller than the air gap between the second lens group and the third lens group along the optical axis, and the air gap between the second lens group and the third lens group along the optical axis may be the largest air gap among all air gaps between lenses in the optical imaging system along the optical axis.

[0021] The air gap between the first lens group and the second lens group along the optical axis may be greater than the air gap between the second lens group and the third lens group along the optical axis, and the air gap between the first lens group and the second lens group along the optical axis may be the largest air gap among all air gaps between lenses in the optical imaging system along the optical axis.

[0022] The first lens group also includes a second lens disposed on the image side of the first lens, the second lens group includes a third lens disposed on the image side of the second lens, and the third lens group includes a fourth lens disposed on the image side of the third lens and a fifth lens disposed on the image side of the fourth lens.

[0023] In another general aspect, an optical imaging system includes a first lens group disposed on an optical axis of the optical imaging system at an object side of the optical imaging system; and a second lens group disposed on the optical axis between the first lens group and an imaging plane of the optical imaging system, wherein the first lens group is configured to be movable between a first position and a second position, wherein at the first position, a first length of the optical imaging system along the optical axis from the object side surface of the first lens group to the imaging plane is TL, and at the second position, a second length of the optical imaging system along the optical axis from the object side surface of the first lens group to the imaging plane is TLs, and TL and TLs satisfy a conditional expression of 0.70. <TLs / TL<0.79。

[0024] The first lens group disposed at the first position may enable the optical imaging system to form an image of the object on the imaging plane, and the first lens group disposed at the second position may disable the optical imaging system from forming an image of the object on the imaging plane.

[0025] The optical imaging system may include a plurality of lenses arranged in sequence along the optical axis from an object side of the optical imaging system toward an imaging plane and divided into a first lens group and a second lens group, the plurality of lenses may be separated from each other by corresponding air gaps along the optical axis, and when the first lens group is arranged at a first position, the air gap between the first lens group and the second lens group may be a maximum air gap Gmax among all air gaps between the plurality of lenses, and may satisfy a conditional expression of 1.5 mm <Gmax。

[0026] The first lens group may include a total of five lenses, and the second lens group may include a total of one lens.

[0027] The first lens group may include a total of six lenses, and the second lens group may include a total of one lens.

[0028] The first lens group may include a total of seven lenses, and the second lens group may include a total of one lens.

[0029] The first lens group may include a total of four lenses, and the second lens group may include a total of two lenses.

[0030] The first lens group may include a total of five lenses, and the second lens group may include a total of two lenses.

[0031] The first lens group may include a total of six lenses, and the second lens group may include a total of two lenses.

[0032] The first lens group may include a total of four lenses, and the second lens group may include a total of three lenses.

[0033] The optical imaging system may further include a third lens group disposed between the second lens group and the imaging surface, wherein the first lens group may include a total of two lenses, the second lens group may include a total of one lens, and the third lens group may include a total of two lenses.

[0034] In another general aspect, a camera module includes the above-described optical imaging system, a first lens barrel having a first lens group disposed therein, and a second lens barrel having a second lens group disposed therein, wherein the first lens barrel is configured to be movable to move the first lens group between a first position and a second position.

[0035] In another general aspect, a mobile terminal device includes the above-mentioned camera module.

[0036] In another general aspect, an optical imaging system includes a first lens group disposed on an optical axis of the optical imaging system at an object side of the optical imaging system, a second lens group disposed on the optical axis between the first lens group and an imaging plane of the optical imaging system, and a third lens group disposed on the optical axis between the second lens group and the imaging plane, wherein the first lens group and the second lens group are configured to be movable between respective first positions and respective second positions, wherein at the first position, a first length of the optical imaging system along the optical axis from the object side surface of the first lens group to the imaging plane is TL, and at the second position, a second length of the optical imaging system along the optical axis from the object side surface of the first lens group to the imaging plane is TLs, and TL and TLs satisfy a conditional expression of 0.70. <TLs / TL<0.79。

[0037] The first lens group and the second lens group set at the corresponding first positions can enable the optical imaging system to form an image of the object on the imaging plane, and the first lens group and the second lens group set at the corresponding second positions can prevent the optical imaging system from forming an image of the object on the imaging plane.

[0038] The optical imaging system may include a plurality of lenses arranged in sequence along the optical axis from the object side of the optical imaging system toward the imaging plane and divided into a first lens group, a second lens group, and a third lens group, the plurality of lenses may be separated from each other by respective air gaps along the optical axis, and when the first lens group and the second lens group are arranged at respective first positions, the air gap between the second lens group and the third lens group may be a maximum air gap Gmax among all air gaps between the plurality of lenses and may satisfy a conditional expression of 1.5 mm <Gmax。

[0039] The first lens group may include a total of two lenses, the second lens group may include a total of one lens, and the third lens group may include a total of two lenses.

[0040] In another general aspect, a camera module includes the above-mentioned optical imaging system, a first lens barrel in which a first lens group is disposed, a second lens barrel in which a second lens group is disposed, and a third lens barrel in which a third lens group is disposed, wherein the first lens barrel and the second lens barrel are configured to be movable to move the first lens group and the second lens group between a corresponding first position and a corresponding second position.

[0041] In another general aspect, a mobile terminal device includes the above-mentioned camera module.

[0042] Other features and aspects will become apparent from the following detailed description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a view showing a first example of the optical imaging system.

[0044] Figure 2 It shows Figure 1 A view of the collapsed state of the optical imaging system shown in FIG.

[0045] Figure 3 It shows Figure 1 A view of the aberration curves of the optical imaging system shown in .

[0046] Figure 4 is a view showing a second example of the optical imaging system.

[0047] Figure 5 It shows Figure 4 A view of the collapsed state of the optical imaging system shown in FIG.

[0048] Figure 6 It shows Figure 4 A view of the aberration curves of the optical imaging system shown in .

[0049] Figure 7 is a view showing a third example of the optical imaging system.

[0050] Figure 8 It shows Figure 7 A view of the collapsed state of the optical imaging system shown in FIG.

[0051] Figure 9 It shows Figure 7 A view of the aberration curves of the optical imaging system shown in .

[0052] Figure 10 is a view showing a fourth example of the optical imaging system.

[0053] Figure 11 It shows Figure 10 A view of the collapsed state of the optical imaging system shown in FIG.

[0054] Figure 12 It shows Figure 10 A view of the aberration curves of the optical imaging system shown in .

[0055] Figure 13 is a view showing a fifth example of the optical imaging system.

[0056] Figure 14 It shows Figure 13 A view of the collapsed state of the optical imaging system shown in FIG.

[0057] Figure 15 It shows Figure 13 A view of the aberration curves of the optical imaging system shown in .

[0058] Figure 16 is a view showing a sixth example of the optical imaging system.

[0059] Figure 17 It shows Figure 16 A view of the collapsed state of the optical imaging system shown in FIG.

[0060] Figure 18 It shows Figure 16 A view of the aberration curves of the optical imaging system shown in .

[0061] Figure 19 is a view showing a seventh example of the optical imaging system.

[0062] Figure 20 It shows Figure 19 A view of the collapsed state of the optical imaging system shown in FIG.

[0063] Figure 21 It shows Figure 19 A view of the aberration curves of the optical imaging system shown in .

[0064] Figure 22 is a view showing an eighth example of the optical imaging system.

[0065] Figure 23 It shows Figure 22 A view of the collapsed state of the optical imaging system shown in FIG.

[0066] Figure 24 It shows Figure 22 A view of the aberration curves of the optical imaging system shown in .

[0067] Figure 25 is a view showing a ninth example of the optical imaging system.

[0068] Figure 26 It shows Figure 25 A view of the collapsed state of the optical imaging system shown in FIG.

[0069] Figure 27 It shows Figure 25 A view of the aberration curves of the optical imaging system shown in .

[0070] Figure 28 is a cross-sectional view of a first example of a camera module, the camera module including Figure 1 A first example of an optical imaging system is shown in .

[0071] Figure 29 is in a contracted state, Figure 28 A cross-sectional view of the camera module is shown in FIG.

[0072] Figure 30 is included Figure 28 sectional view of a first example of a mobile terminal device showing a camera module.

[0073] Figure 31 is a camera module in a retracted state, Figure 30 A cross-sectional view of the mobile terminal device shown in FIG.

[0074] Figure 32 is a cross-sectional view of a second example of a camera module, the camera module including Figure 22 An eighth example of the optical imaging system is shown in .

[0075] Figure 33 is in a contracted state, Figure 32 A cross-sectional view of the camera module is shown in .

[0076] Figure 34 is included Figure 33 sectional view of a second example of a mobile terminal device showing a camera module.

[0077] Figure 35 is a camera module in a retracted state, Figure 34 A cross-sectional view of the mobile terminal device shown in FIG.

[0078] In all drawings and detailed description, the same reference numerals refer to the same elements. For the purpose of clarity, illustration and convenience, the drawings may not be drawn to scale, and the relative sizes, proportions and depictions of elements in the drawings may be exaggerated. DETAILED DESCRIPTION

[0079] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the application, various changes, modifications and equivalences of the methods, devices and / or systems described herein will be apparent. For example, except for the operations that must occur in a specific order, the order of operations described herein is merely an example and is not limited to the order set forth herein, but can be made to make changes that will be apparent after understanding the disclosure of the application. In addition, for greater clarity and brevity, the description of functions and structures well known in the art may be omitted.

[0080] The features described herein may be implemented 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, devices, and / or systems described herein, which will become apparent upon understanding the disclosure of this application.

[0081] Use of the word "may" in describing various examples herein (eg, with respect to what an example may include or implement) means that there is at least one example in which such feature is included or implemented, and all examples are not limited thereto.

[0082] Throughout the specification, when an element such as a layer, a region, or a substrate is described as being “on,” “connected to,” or “coupled to” another element, the element may 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. Conversely, when an element is described as being “directly on,” “directly connected to,” or “directly coupled to” another element, there are no other elements present between the element and the other element.

[0083] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0084] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are used only to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Thus, a first member, first component, first region, first layer, or first portion mentioned in the examples described herein 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.

[0085] Spatially relative terms such as "above," "upper," "below," and "lower" may be used herein for descriptive convenience to describe the relationship of one element relative to another element as shown in the accompanying drawings. In addition to covering the orientations depicted in the accompanying drawings, these spatially relative terms are intended to cover different orientations of the device in use or operation. For example, if the device in the drawings is turned over, an element described as being "above" or "above" relative to another element will be "below" or "lower" relative to the other element. Thus, the term "above" covers both "above" and "below" orientations, depending on the spatial orientation of the device. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein should be interpreted accordingly.

[0086] The terms used herein are for describing various examples only and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the articles "a", "an" and "the" are intended to include plural forms as well. The terms "comprise", "include" and "have" indicate the presence of stated features, numbers, operations, components, elements and / or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, components, elements and / or combinations thereof.

[0087] Due to manufacturing techniques and / or tolerances, the shapes shown in the drawings may vary. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shape that occur during manufacturing.

[0088] The features of the examples described herein can be combined in various ways, which will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have multiple configurations, it will be apparent after understanding the disclosure of the present application that other configurations are also possible.

[0089] The optical imaging system includes five, six, seven, or eight lenses arranged sequentially along the optical axis of the optical imaging system from the object side of the optical imaging system toward the imaging plane of the optical imaging system. In the optical imaging system including five, six, seven, or eight lenses, the first lens is the lens closest to the object side of the optical imaging system, and the fifth, sixth, seventh, or eighth lens is the lens closest to the imaging plane, respectively. The lenses are separated from each other by corresponding air gaps along the optical axis.

[0090] In each lens, the object-side surface is the surface of the lens closest to the object side of the optical imaging system, and the image-side surface is the surface of the lens closest to the imaging plane.

[0091] Unless otherwise specified, references to the shape of a lens surface refer to the shape of the paraxial region of the lens surface. The paraxial region of the lens surface is the central portion of the lens surface surrounding and including the optical axis of the lens surface, in which light rays incident on the lens surface form a small angle θ with the optical axis, and the following approximations hold: sinθ≈θ, tanθ≈θ, and cosθ≈1.

[0092] For example, the statement that the object side surface of a lens is convex means that at least the paraxial region of the object side surface of the lens is convex, and the statement that the image side surface of the lens is concave means that at least the paraxial region of the image side surface of the lens is concave. Therefore, even if the object side surface of a lens can be described as convex, the entire object side surface of the lens may not be convex, and the peripheral region of the object side surface of the lens may be concave. In addition, even if the image side surface of a lens can be described as concave, the entire image side surface of the lens may not be concave, and the peripheral region of the image side surface of the lens may be convex.

[0093] Gmax is the maximum air gap among all air gaps between lenses of the optical imaging system.

[0094] TL is the length of the optical imaging system along the optical axis from the object-side surface of the first lens to the imaging plane in an active mode or image capturing mode of the optical imaging system (in this mode, the optical imaging system is capable of capturing an image).

[0095] TLs is the length of the optical imaging system along the optical axis from the object-side surface of the first lens to the imaging plane in an inactive mode of the optical imaging system (in this mode, the optical imaging system cannot capture an image).

[0096] The BFL is the length along the optical axis from the image side surface of the last lens (the fifth lens, the sixth lens, the seventh lens, or the eighth lens) to the image plane.

[0097] IMGHT is the maximum effective image height of the optical imaging system and is equal to half the diagonal length of the maximum effective imaging area of ​​the imaging surface of the image sensor whose imaging surface is set at the imaging plane. In other words, IMGHT is equal to half the maximum effective area of ​​the imaging plane corresponding to the maximum effective imaging area of ​​the imaging surface of the image sensor.

[0098] f is the focal length of the optical imaging system, and f1, f2, f3, f4, f5, f6, f7 and f8 are the corresponding focal lengths of the first lens to the eighth lens of the optical imaging system.

[0099] Fno is the f-number of the optical imaging system, and is equal to the focal length f of the optical imaging system divided by the entrance pupil diameter of the optical imaging system.

[0100] The radius of curvature of the surface of the lens, the thickness of the lens and other elements, the air gap between the lenses, the distance between the lens and other elements, the focal length f of the optical imaging system, the focal lengths f1, f2, f3, f4, f5, f6, f7, and f8 of the first to eighth lenses, Gmax, TL, TLs, BFL, and IMGHT are expressed in millimeters (mm), although other measurement units may also be used. Fno, the refractive index of the lens, and the Abbe number of the lens are dimensionless quantities.

[0101] The thickness of lenses and other components, the air gap between lenses, the distance between lenses and other components, Gmax, TL, TLs, and BFL are measured along the optical axis of the optical imaging system.

[0102] An example of an optical imaging system may include multiple lenses. For example, the optical imaging system may include five lenses, six lenses, seven lenses, or eight lenses. The optical imaging system may be configured such that the multiple lenses are arranged in sequence along the optical axis of the optical imaging system from the object side of the optical imaging system to the imaging surface of the optical imaging system. The multiple lenses may be spaced apart from each other by air gaps. For example, the length TL of the optical imaging system (the length along the optical axis between the object surface of the first lens closest to the object side of the optical imaging system and the imaging surface of the optical imaging system) may be less than 12.0 mm. The optical imaging system may be configured to change the length TL. For example, the optical imaging system may be configured to reduce the length TL by reducing the air gap between two of the lenses in the optical imaging system. The optical imaging system may be configured to significantly reduce the length TL of the optical imaging system. For example, the maximum air gap Gmax among all the air gaps between the lenses of the optical imaging system may be greater than 1.5 mm. The focal length f of the optical imaging system and the radius of curvature R1 of the object surface of the first lens of the optical imaging system may satisfy a predetermined conditional expression. For example, the optical imaging system may satisfy any one of the following conditional expressions 1 to conditional expression 3 or any combination of any two or more of them.

[0103] 1.5 mm < Gmax (conditional expression 1)

[0104] TL < 12.0 mm (conditional expression 2)

[0105] 0.15 < R1 / f (conditional expression 3)

[0106] Alternatively, f and R1 may satisfy the following conditional expression 4.

[0107] 0.15 < R1 / f < 0.5 (conditional expression 4)

[0108] The first lens of the optical imaging system may have a predetermined refractive power. For example, the first lens may have a positive refractive power. One surface of the first lens may be concave. For example, the first lens may have a concave image side surface.

[0109] Another example of an optical imaging system may include a plurality of lens groups. For example, the optical imaging system may include a first lens group and a second lens group. The first lens group may include a first lens disposed closest to the object side of the optical imaging system. However, the first lens group is not limited to only the first lens. The first lens group may be movable to increase and decrease the distance between the first lens group and the second lens group. For example, the distance between the first lens group and the second lens group may increase in the activation mode of the optical imaging system and may decrease in the non-activation mode of the optical imaging system. Therefore, the length of the optical imaging system may contract at a predetermined ratio in the non-activation mode. For example, the ratio (TLs / TL) of the length TLs of the optical imaging system in the non-activation mode of the optical imaging system to the length TL in the activation mode may be greater than 0.65 and less than 0.79. Alternatively, TL / TL may be greater than 0.70 and less than 0.79. In other words, TLs and TL may satisfy one of the following conditional expressions 5 and expression 6.

[0110] 0.65 < TLs / TL < 0.79 (conditional expression 5)

[0111] 0.70 < TLs / TL < 0.79 (conditional expression 6)

[0112] The first lens group and the second lens group may be spaced apart from each other by an air gap. For example, the air gap between the first lens group and the second lens group may be greater than 1.9 mm and less than 2.8 mm, and may be the maximum air gap Gmax in the optical imaging system.

[0113] The optical imaging system may further include a third lens group. For example, a third lens group including one or more lenses may be disposed on the image side of the second lens group. The second lens group and the third lens group may be spaced apart from each other by an air gap. For example, the air gap between the second lens group and the third lens group may be greater than 2.0 mm and less than 2.8 mm, and may be the maximum air gap Gmax in the optical imaging system. The air gap between the first lens and the second lens group and the air gap between the second lens group and the third lens group may have a predetermined dimensional relationship with each other. For example, the air gap between the first lens group and the second lens group may be less than the air gap between the second lens group and the third lens group. Alternatively, the air gap between the first lens group and the second lens group may be greater than the air gap between the second lens group and the third lens group.

[0114] Each of the first lens group, the second lens group, and the third lens group may include at least one lens. For example, the first lens group may include a first lens and a second lens disposed in ascending order along the optical axis of the optical imaging system from the object side of the first lens group toward the imaging plane of the optical imaging system, the second lens group may include a third lens disposed on the image side of the second lens on the optical axis, and the third lens group may include a fourth lens and a fifth lens disposed on the image side of the third lens in ascending order along the optical axis from the object side of the first lens group to the imaging plane.

[0115] In the following description, components of the optical imaging system will be described in detail.

[0116] The optical imaging system includes five or more lenses. For example, the optical imaging system may include a first lens, a second lens, a third lens, a fourth lens, and a fifth lens disposed in ascending order along the optical axis of the optical imaging system from the object side of the optical imaging system toward the imaging plane of the optical imaging system. However, the optical imaging system is not limited to only five lenses. For example, the optical imaging system may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens disposed in ascending order along the optical axis of the optical imaging system from the object side of the optical imaging system toward the imaging plane of the optical imaging system. Alternatively, the optical imaging system may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens disposed in ascending order along the optical axis of the optical imaging system from the object side of the optical imaging system toward the imaging plane of the optical imaging system. Alternatively, the optical imaging system may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens disposed in ascending order along the optical axis of the optical imaging system from the object side of the optical imaging system toward the imaging plane of the optical imaging system.

[0117] The first lens has a predetermined refractive power. For example, the first lens may have positive refractive power. One surface of the first lens may be concave. For example, the first lens may have a concave image-side surface. However, the shape of the first lens is not limited to this shape. For example, the first lens may have a convex object-side surface and a convex image-side surface. The first lens has a predetermined refractive index. For example, the refractive index of the first lens may be greater than or equal to 1.5 and less than 1.6. The first lens may have a predetermined focal length. For example, the focal length of the first lens may be in the range of 3.0 mm to 9.0 mm.

[0118] The second lens has a predetermined refractive power. For example, the second lens may have negative refractive power. One surface of the second lens may be concave. For example, the second lens may have a concave image-side surface. The second lens has a predetermined refractive index. For example, the refractive index of the second lens may be greater than or equal to 1.6 and less than 1.7. The second lens may have a predetermined focal length. For example, the focal length of the second lens may be in the range of -60 mm to -7.0 mm.

[0119] The third lens element has a predetermined refractive power. For example, the third lens element may have positive or negative refractive power. One surface of the third lens element may be concave. For example, the third lens element may have a concave object-side surface or a concave image-side surface. The third lens element may have a predetermined refractive index. For example, the refractive index of the third lens element may be greater than or equal to 1.53 and less than 1.7.

[0120] The fourth lens element has a predetermined refractive power. For example, the fourth lens element may have positive or negative refractive power. One surface of the fourth lens element may be concave. For example, the fourth lens element may have a concave object-side surface or a concave image-side surface. The fourth lens element has a predetermined refractive index. For example, the refractive index of the fourth lens element may be greater than or equal to 1.53 and less than 1.7.

[0121] The fifth lens has a predetermined refractive power. For example, the fifth lens may have positive refractive power or negative refractive power. One surface of the fifth lens may be convex, or both surfaces of the fifth lens may be concave. For example, a fifth lens with positive refractive power may have a convex object-side surface or a convex image-side surface, and a fifth lens with negative refractive power may have a concave object-side surface and a concave image-side surface. The fifth lens may have a predetermined refractive index. For example, the refractive index of the fifth lens may be greater than or equal to 1.5 and less than 1.7.

[0122] The sixth lens element has a predetermined refractive power. For example, the sixth lens element may have positive or negative refractive power. One surface of the sixth lens element may be convex. For example, the sixth lens element may have a convex object-side surface or a convex image-side surface. The sixth lens element may have a predetermined refractive index. For example, the refractive index of the sixth lens element may be greater than or equal to 1.5 and less than 1.6.

[0123] The seventh lens has a predetermined refractive power. For example, the seventh lens may have positive or negative refractive power. One surface of the seventh lens may be concave. For example, the seventh lens may have a concave object-side surface or a concave image-side surface. However, a seventh lens disposed on the image side of the sixth lens having negative refractive power may have a convex object-side surface and a convex image-side surface. The seventh lens may have a predetermined refractive index. For example, the refractive index of the seventh lens may be greater than or equal to 1.5 and less than 1.6.

[0124] The eighth lens has a predetermined refractive power. For example, the eighth lens may have a negative refractive power. One surface of the eighth lens may be concave. For example, the eighth lens may have a concave image side. The eighth lens may have a predetermined refractive index. For example, the refractive index of the eighth lens may be greater than or equal to 1.5 and less than 1.6.

[0125] The optical imaging system may include a plastic lens. For example, among five or more lenses of the optical imaging system, at least one lens may be made of a plastic material.

[0126] The optical imaging system may include an aspherical lens. For example, among five or more lenses of the optical imaging system, at least one lens may have an aspherical object side and an aspherical image side. Each aspherical surface is defined by the following Equation 1:

[0127]

[0128] In Equation 1, c is the curvature of the lens surface and is equal to the reciprocal of the radius of curvature of the lens surface at the optical axis of the lens surface, k is the conic constant, r is the distance from any point on the lens surface to the optical axis of the lens surface in a direction perpendicular to the optical axis of the lens surface, A, B, C, D, E, F, G, H, J, L, M, N, O, and P are aspherical constants, and Z (also known as sag) is the distance from a point on the lens surface at a distance r from the optical axis of the lens surface to the tangent plane perpendicular to the optical axis and intersecting the vertex of the lens surface in a direction parallel to the optical axis of the lens surface.

[0129] The optical imaging system may further include a filter disposed between the last lens and the imaging surface. The filter may block incident light of a specific wavelength from entering the optical imaging system. For example, the filter may block incident light of an infrared wavelength. The optical imaging system may further include an image sensor having an imaging surface disposed at the imaging surface. The image sensor may be configured to convert an optical image formed by the optical imaging system on the imaging surface into an electrical signal. The image sensor may be a charge-coupled device (CCD) image sensor, but is not limited thereto.

[0130] The optical imaging system may satisfy any one or any combination of any two or more of the following conditional expressions 7 to conditional expression 12.

[0131] 0.001 < D12 / f < 0.04 (conditional expression 7)

[0132] -3.0 < f / f2 + f / f3 (conditional expression 8)

[0133] 3.2 < Nd2 + Nd3 (conditional expression 9)

[0134] 0.6 < TL / f < 1.3 (Conditional Expression 10)

[0135] 0.12 < BFL / f < 0.26 (Conditional Expression 11)

[0136] Fno < 2.5 (Conditional Expression 12)

[0137] In Conditional Expressions 7 to 12, D12 is the distance along the optical axis of the optical imaging system from the image side surface of the first lens to the object side surface of the second lens, f is the focal length of the optical imaging system, f2 is the focal length of the second lens, f3 is the focal length of the third lens, Nd2 is the refractive index of the second lens, Nd3 is the refractive index of the third lens, TL is the length along the optical axis between the object side surface of the first lens and the imaging surface of the optical imaging system in the active mode of the optical imaging system, BFL is the length along the optical axis between the image side surface of the last lens closest to the imaging surface and the imaging surface, and Fno is the f-number of the optical imaging system and is equal to the focal length f of the optical imaging system divided by the entrance pupil diameter of the optical imaging system.

[0138] The optical imaging system may also satisfy any one or any combination of any two or more of the following Conditional Expressions 13 to 15.

[0139] 0.20 < Gmax / TL < 0.30 (Conditional Expression 13)

[0140] -3.0 < f / f2 + f / f3 < 0 (Conditional Expression 14)

[0141] 3.2 < Nd2 + Nd3 < 3.5 (Conditional Expression 15)

[0142] In Conditional Expression 15, Gmax is the maximum air gap among all the air gaps between the lenses of the optical imaging system.

[0143] In the following description, various examples of the optical imaging system will be described.

[0144] Figure 1 is a view showing a first example of the optical imaging system,<e Figure 2 is showing Figure 1 the contracted state of the optical imaging system shown in, and Figure 3 is showing Figure 1 the aberration curve of the optical imaging system shown in.

[0145] Refer to Figure 1 , the optical imaging system 100 may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a filter IF, and an imaging surface IP.

[0146] The first lens 110 may have positive refractive power. The first lens 110 may have a convex object-side surface and a concave image-side surface. The second lens 120 may have negative refractive power. The second lens 120 may have a convex object-side surface and a concave image-side surface. The third lens 130 may have negative refractive power. The third lens 130 may have a convex object-side surface and a concave image-side surface. The fourth lens 140 may have positive refractive power. The fourth lens 140 may have a convex object-side surface and a concave image-side surface. The fifth lens 150 may have positive refractive power. The fifth lens 150 may have a convex object-side surface and a convex image-side surface. An inflection point may be formed on the object-side surface of the fifth lens 150. The sixth lens 160 may have negative refractive power. The sixth lens 160 may have a convex object-side surface and a concave image-side surface. Inflection points may be formed on both the object-side surface and the image-side surface of the sixth lens 160.

[0147] Optical imaging system 100 may include multiple lens groups. For example, first lens 110 through fifth lens 150 may constitute first lens group G1, and sixth lens 160 may constitute second lens group G2. The air gap between first lens group G1 and second lens group G2 may be the maximum air gap Gmax in optical imaging system 100. In other words, the air gap between fifth lens 150 and sixth lens 160 may be greater than all other air gaps between lenses in optical imaging system 100.

[0148] like Figure 2 As shown in , the first lens group G1 can be moved closer to the second lens group G2 to reduce the length of the optical imaging system 100. The positional movement of the first lens group G1 can be performed selectively. For example, the first lens group G1 can be arranged to provide a maximum distance to the second lens group G2 in the active mode of the optical imaging system 100 (a mode in which images can be captured), and can be arranged to provide a minimum distance to the second lens group G2 in the inactive mode of the optical imaging system 100 (a mode in which images cannot be captured). The length of the optical imaging system 100 (the distance between the object-side surface of the first lens 110 and the imaging plane IP) can vary depending on the position of the first lens group G1. For example, the length TL of the optical imaging system 100 in the active mode can be greater than the length TLs of the optical imaging system 100 in the inactive mode. Therefore, the optical imaging system 100 can alleviate the problem of the camera module protruding outward from the mobile terminal device when the camera module is not in use.

[0149] The characteristics of the lenses and other elements of the optical imaging system 100 are listed in Table 1 below, and the aspheric constants of the surfaces of the lenses of the optical imaging system 100 are listed in Table 2 below.

[0150] The bold value 2.200 in the Thickness / Distance column in Table 1 is the maximum air gap Gmax, which is the air gap between the first lens group G1 and the second lens group G2 and is also the air gap between the fifth lens 150 and the sixth lens 160 .

[0151] Table 1

[0152]

[0153] Table 2

[0154]

[0155]

[0156] Figure 4 is a view showing a second example of the optical imaging system, Figure 5 It shows Figure 4 A view of the collapsed state of the optical imaging system shown in , and Figure 6 It shows Figure 4 A view of the aberration curves of the optical imaging system shown in .

[0157] refer to Figure 4 The optical imaging system 200 may include a first lens 210, a second lens 220, a third lens 230, a fourth lens 240, a fifth lens 250, a sixth lens 260, a filter IF and an imaging surface IP.

[0158] The first lens 210 may have positive refractive power. The first lens 210 may have a convex object-side surface and a concave image-side surface. The second lens 220 may have negative refractive power. The second lens 220 may have a convex object-side surface and a concave image-side surface. The third lens 230 may have positive refractive power. The third lens 230 may have a concave object-side surface and a convex image-side surface. The fourth lens 240 may have negative refractive power. The fourth lens 240 may have a concave object-side surface and a convex image-side surface. The fifth lens 250 may have positive refractive power. The fifth lens 250 may have a convex object-side surface and a concave image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the fifth lens 250. The sixth lens 260 may have negative refractive power. The sixth lens 260 may have a convex object-side surface and a concave image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the sixth lens 260.

[0159] Optical imaging system 200 may include multiple lens groups. For example, first lens 210 through fourth lens 240 may constitute first lens group G1, and fifth lens 250 and sixth lens 260 may constitute second lens group G2. The air gap between first lens group G1 and second lens group G2 may be the maximum air gap Gmax in optical imaging system 200. In other words, the air gap between fourth lens 240 and fifth lens 250 may be greater than all other air gaps between lenses in optical imaging system 200.

[0160] like Figure 5 As shown in FIG, the first lens group G1 can be moved closer to the second lens group G2 to reduce the length of the optical imaging system 200. This positional shift of the first lens group G1 can be performed selectively. For example, the first lens group G1 can be positioned to provide a maximum distance from the second lens group G2 in the active mode of the optical imaging system 200 (a mode in which images can be captured), and can be positioned to provide a minimum distance from the second lens group G2 in the inactive mode of the optical imaging system 200 (a mode in which images cannot be captured). The length of the optical imaging system 200 (the distance between the object-side surface of the first lens 210 and the imaging plane IP) can vary depending on the position of the first lens group G1. For example, the length TL of the optical imaging system 200 in the active mode can be greater than the length TLs of the optical imaging system 200 in the inactive mode. Therefore, the optical imaging system 200 can alleviate the problem of the camera module protruding outward from the mobile terminal device when the camera module is not in use.

[0161] The characteristics of the lenses and other elements of the optical imaging system 200 are listed in Table 3 below, and the aspheric constants of the surfaces of the lenses of the optical imaging system 200 are listed in Table 4 below.

[0162] The bold value 2.000 in the Thickness / Distance column in Table 3 is the maximum air gap Gmax, which is the air gap between the first lens group G1 and the second lens group G2 and is also the air gap between the fourth lens 240 and the fifth lens 250 .

[0163] Table 3

[0164]

[0165] Table 4

[0166]

[0167]

[0168] Figure 7 is a view showing a third example of the optical imaging system, Figure 8 It shows Figure 7 A view of the collapsed state of the optical imaging system shown in , and Figure 9 It shows Figure 7 A view of the aberration curves of the optical imaging system shown in .

[0169] refer to Figure 7 The optical imaging system 300 may include a first lens 310, a second lens 320, a third lens 330, a fourth lens 340, a fifth lens 350, a sixth lens 360, a seventh lens 370, a filter IF and an imaging surface IP.

[0170] The first lens 310 may have positive refractive power. The first lens 310 may have a convex object-side surface and a concave image-side surface. The second lens 320 may have negative refractive power. The second lens 320 may have a convex object-side surface and a concave image-side surface. The third lens 330 may have positive refractive power. The third lens 330 may have a convex object-side surface and a concave image-side surface. The fourth lens 340 may have negative refractive power. The fourth lens 340 may have a concave object-side surface and a concave image-side surface. The fifth lens 350 may have negative refractive power. The fifth lens 350 may have a concave object-side surface and a concave image-side surface. An inflection point may be formed on the object-side surface or the image-side surface of the fifth lens 350. The sixth lens 360 may have positive refractive power. The sixth lens 360 may have a convex object-side surface and a convex image-side surface. An inflection point may be formed on the object-side surface and the image-side surface of the sixth lens 360. The seventh lens 370 may have negative refractive power. The seventh lens element 370 may have a concave object-side surface and a concave image-side surface, and may have inflection points formed on the object-side surface and the image-side surface of the seventh lens element 370 .

[0171] Optical imaging system 300 may include multiple lens groups. For example, first lens 310 through sixth lens 360 may constitute first lens group G1, and seventh lens 370 may constitute second lens group G2. The air gap between first lens group G1 and second lens group G2 may be the maximum air gap Gmax in optical imaging system 300. In other words, the air gap between sixth lens 360 and seventh lens 370 may be greater than all other air gaps between lenses in optical imaging system 300.

[0172] like Figure 8As shown in FIG, the first lens group G1 can be moved closer to the second lens group G2 to reduce the length of the optical imaging system 300. This positional shift of the first lens group G1 can be performed selectively. For example, the first lens group G1 can be positioned to provide a maximum distance from the second lens group G2 in the active mode of the optical imaging system 300 (a mode in which images can be captured), and can be positioned to provide a minimum distance from the second lens group G2 in the inactive mode of the optical imaging system 300 (a mode in which images cannot be captured). The length of the optical imaging system 300 (the distance between the object-side surface of the first lens 310 and the imaging plane IP) can vary depending on the position of the first lens group G1. For example, the length TL of the optical imaging system 300 in the active mode can be greater than the length TLs of the optical imaging system 300 in the inactive mode. Therefore, the optical imaging system 300 can alleviate the problem of the camera module protruding outward from the mobile terminal device when the camera module is not in use.

[0173] The characteristics of the lenses and other elements of the optical imaging system 300 are listed in Table 5 below, and the aspheric constants of the surfaces of the lenses of the optical imaging system 300 are listed in Table 6 below.

[0174] The bold value 2.400 in the Thickness / Distance column in Table 5 is the maximum air gap Gmax, which is the air gap between the first lens group G1 and the second lens group G2 and is also the air gap between the sixth lens 360 and the seventh lens 370 .

[0175] Table 5

[0176]

[0177]

[0178] Table 6

[0179]

[0180]

[0181] Figure 10 is a view showing a fourth example of the optical imaging system, Figure 11 It shows Figure 10 A view of the collapsed state of the optical imaging system shown in , and Figure 12 It shows Figure 10 A view of the aberration curves of the optical imaging system shown in .

[0182] refer to Figure 10 The optical imaging system 400 may include a first lens 410, a second lens 420, a third lens 430, a fourth lens 440, a fifth lens 450, a sixth lens 460, a seventh lens 470, a filter IF and an imaging surface IP.

[0183] The first lens 410 may have positive refractive power. The first lens 410 may have a convex object-side surface and a concave image-side surface. The second lens 420 may have negative refractive power. The second lens 420 may have a convex object-side surface and a concave image-side surface. The third lens 430 may have negative refractive power. The third lens 430 may have a convex object-side surface and a concave image-side surface. The fourth lens 440 may have negative refractive power. The fourth lens 440 may have a concave object-side surface and a concave image-side surface. The fifth lens 450 may have positive refractive power. The fifth lens 450 may have a convex object-side surface and a convex image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the fifth lens 450. The sixth lens 460 may have positive refractive power. The sixth lens 460 may have a concave object-side surface and a convex image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the sixth lens 460. The seventh lens 470 may have negative refractive power. The seventh lens element 470 may have a convex object-side surface and a concave image-side surface, and may have inflection points formed on the object-side surface and the image-side surface of the seventh lens element 470 .

[0184] Optical imaging system 400 may include multiple lens groups. For example, first lens 410 through fifth lens 450 may constitute first lens group G1, and sixth lens 460 and seventh lens 470 may constitute second lens group G2. The air gap between first lens group G1 and second lens group G2 may be the maximum air gap Gmax in optical imaging system 400. In other words, the air gap between fifth lens 450 and sixth lens 460 may be greater than all other air gaps between lenses in optical imaging system 400.

[0185] like Figure 11 As shown in , the first lens group G1 can be moved closer to the second lens group G2 to reduce the length of the optical imaging system 400. This positional shift of the first lens group G1 can be performed selectively. For example, the first lens group G1 can be positioned to provide a maximum distance from the second lens group G2 in the active mode of the optical imaging system 400 (a mode in which images can be captured), and can be positioned to provide a minimum distance from the second lens group G2 in the inactive mode of the optical imaging system 400 (a mode in which images cannot be captured). The length of the optical imaging system 400 (the distance between the object-side surface of the first lens 410 and the imaging plane IP) can vary depending on the position of the first lens group G1. For example, the length TL of the optical imaging system 400 in the active mode can be greater than the length TLs of the optical imaging system 400 in the inactive mode. Therefore, the optical imaging system 400 can alleviate the problem of the camera module protruding outward from the mobile terminal device when the camera module is not in use.

[0186] The characteristics of the lenses and other elements of the optical imaging system 400 are listed in Table 7 below, and the aspheric constants of the surfaces of the lenses of the optical imaging system are listed in Table 8 below.

[0187] The bold value 2.050 in the Thickness / Distance column in Table 7 is the maximum air gap Gmax, which is the air gap between the first lens group G1 and the second lens group G2 and is also the air gap between the fifth lens 450 and the sixth lens 460 .

[0188] Table 7

[0189]

[0190]

[0191] Table 8

[0192]

[0193]

[0194] Figure 13 is a view showing a fifth example of the optical imaging system, Figure 14 It shows Figure 13 A view of the collapsed state of the optical imaging system shown in , and Figure 15 It shows Figure 13 A view of the aberration curves of the optical imaging system shown in .

[0195] refer to Figure 13 The optical imaging system 500 may include a first lens 510, a second lens 520, a third lens 530, a fourth lens 540, a fifth lens 550, a sixth lens 560, a seventh lens 570, a filter IF and an imaging surface IP.

[0196] The first lens 510 may have positive refractive power. The first lens 510 may have a convex object-side surface and a concave image-side surface. The second lens 520 may have negative refractive power. The second lens 520 may have a convex object-side surface and a concave image-side surface. The third lens 530 may have negative refractive power. The third lens 530 may have a concave object-side surface and a convex image-side surface. The fourth lens 540 may have negative refractive power. The fourth lens 540 may have a concave object-side surface and a convex image-side surface. The fifth lens 550 may have positive refractive power. The fifth lens 550 may have a concave object-side surface and a convex image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the fifth lens 550. The sixth lens 560 may have positive refractive power. The sixth lens 560 may have a convex object-side surface and a concave image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the sixth lens 560. The seventh lens 570 may have positive refractive power. The seventh lens element 570 may have a convex object-side surface and a concave image-side surface, and may have inflection points formed on the object-side surface and the image-side surface of the seventh lens element 570 .

[0197] Optical imaging system 500 may include multiple lens groups. For example, first lens 510 through fourth lens 540 constitute first lens group G1, and fifth lens 550 through seventh lens 570 constitute second lens group G2. The air gap between first lens group G1 and second lens group G2 may be the maximum air gap Gmax in optical imaging system 500. In other words, the air gap between fourth lens 540 and fifth lens 550 may be greater than all other air gaps between lenses in optical imaging system 500.

[0198] like Figure 14 As shown in , the first lens group G1 can be moved closer to the second lens group G2 to reduce the length of the optical imaging system 500. This positional shift of the first lens group G1 can be performed selectively. For example, the first lens group G1 can be positioned to provide a maximum distance from the second lens group G2 in the active mode of the optical imaging system 500 (a mode in which images can be captured), and can be positioned to provide a minimum distance from the second lens group G2 in the inactive mode of the optical imaging system 500 (a mode in which images cannot be captured). The length of the optical imaging system 500 (the distance between the object-side surface of the first lens 510 and the imaging plane IP) can vary depending on the position of the first lens group G1. For example, the length TL of the optical imaging system 500 in the active mode can be greater than the length TLs of the optical imaging system 500 in the inactive mode. Therefore, the optical imaging system 500 can alleviate the problem of the camera module protruding outward from the mobile terminal device when the camera module is not in use.

[0199] The characteristics of the lenses and other elements of the optical imaging system 500 are listed in Table 9 below, and the aspheric constants of the surfaces of the lenses of the optical imaging system 500 are listed in Table 10 below.

[0200] The bold value 2.000 in the Thickness / Distance column in Table 9 is the maximum air gap Gmax, which is the air gap between the first lens group G1 and the second lens group G2 and is also the air gap between the fourth lens 540 and the fifth lens 550 .

[0201] Table 9

[0202]

[0203]

[0204] Table 10

[0205]

[0206]

[0207] Figure 16 is a view showing a sixth example of the optical imaging system, Figure 17It shows Figure 16 A view of the collapsed state of the optical imaging system shown in , and Figure 18 It shows Figure 16 A view of the aberration curves of the optical imaging system shown in .

[0208] refer to Figure 16 The optical imaging system 600 may include a first lens 610, a second lens 620, a third lens 630, a fourth lens 640, a fifth lens 650, a sixth lens 660, a seventh lens 670, an eighth lens 680, a filter IF and an imaging surface IP.

[0209] The first lens 610 may have positive refractive power. The first lens 610 may have a convex object-side surface and a concave image-side surface. The second lens 620 may have negative refractive power. The second lens 620 may have a convex object-side surface and a concave image-side surface. The third lens 630 may have positive refractive power. The third lens 630 may have a convex object-side surface and a concave image-side surface. The fourth lens 640 may have negative refractive power. The fourth lens 640 may have a concave object-side surface and a concave image-side surface. The fifth lens 650 may have negative refractive power. The fifth lens 650 may have a concave object-side surface and a concave image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the fifth lens 650. The sixth lens 660 may have negative refractive power. The sixth lens 660 may have a convex object-side surface and a concave image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the sixth lens 660. The seventh lens 670 may have positive refractive power. The seventh lens element 670 may have a convex object-side surface and a convex image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the seventh lens element 670. The eighth lens element 680 may have negative refractive power. The eighth lens element 680 may have a concave object-side surface and a concave image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the eighth lens element 680.

[0210] Optical imaging system 600 may include multiple lens groups. For example, first lens 610 through seventh lens 670 may constitute first lens group G1, and eighth lens 680 may constitute second lens group G2. The air gap between first lens group G1 and second lens group G2 may be the maximum air gap Gmax in optical imaging system 600. In other words, the air gap between seventh lens 670 and eighth lens 680 may be greater than all other air gaps between lenses in optical imaging system 600.

[0211] like Figure 17As shown in , the first lens group G1 can be moved closer to one side of the second lens group G2 to reduce the length of the optical imaging system 600. This positional shift of the first lens group G1 can be performed selectively. For example, the first lens group G1 can be positioned to provide a maximum distance from the second lens group G2 in the active mode of the optical imaging system 600 (a mode in which images can be captured), and can be positioned to provide a minimum distance from the second lens group G2 in the inactive mode of the optical imaging system 600 (a mode in which images cannot be captured). The length of the optical imaging system 600 (the distance between the object-side surface of the first lens 610 and the imaging plane IP) can vary depending on the position of the first lens group G1. For example, the length TL of the optical imaging system 600 in the active mode can be greater than the length TLs of the optical imaging system 600 in the inactive mode. Therefore, the optical imaging system 600 can alleviate the problem of the camera module protruding outward from the mobile terminal device when the camera module is not in use.

[0212] The characteristics of the lenses and other elements of the optical imaging system 600 are listed in Table 11 below, and the aspheric constants of the surfaces of the lenses of the optical imaging system 600 are listed in Table 12 below.

[0213] The bold value 2.512 in the Thickness / Distance column in Table 11 is the maximum air gap Gmax, which is the air gap between the first lens group G1 and the second lens group G2, and is also the air gap between the seventh lens 670 and the eighth lens 680.

[0214] Table 11

[0215]

[0216]

[0217] Table 12

[0218]

[0219]

[0220] Figure 19 is a view showing a seventh example of the optical imaging system, Figure 20 It shows Figure 19 A view of the collapsed state of the optical imaging system shown in , and Figure 21 It shows Figure 19 A view of the aberration curves of the optical imaging system shown in .

[0221] refer to Figure 19The optical imaging system 700 may include a first lens 710, a second lens 720, a third lens 730, a fourth lens 740, a fifth lens 750, a sixth lens 760, a seventh lens 770, an eighth lens 780, a filter IF and an imaging surface IP.

[0222] The first lens 710 may have positive refractive power. The first lens 710 may have a convex object-side surface and a concave image-side surface. The second lens 720 may have negative refractive power. The second lens 720 may have a convex object-side surface and a concave image-side surface. The third lens 730 may have negative refractive power. The third lens 730 may have a convex object-side surface and a concave image-side surface. The fourth lens 740 may have negative refractive power. The fourth lens 740 may have a concave object-side surface and a concave image-side surface. The fifth lens 750 may have positive refractive power. The fifth lens 750 may have a convex object-side surface and a concave image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the fifth lens 750. The sixth lens 760 may have positive refractive power. The sixth lens 760 may have a convex object-side surface and a convex image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the sixth lens 760. The seventh lens 770 may have positive refractive power. The seventh lens element 770 may have a concave object-side surface and a convex image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the seventh lens element 770. The eighth lens element 780 may have negative refractive power. The eighth lens element 780 may have a convex object-side surface and a concave image-side surface. Inflection points may be formed on the object-side and image-side surfaces of the eighth lens element 780.

[0223] Optical imaging system 700 may include multiple lens groups. For example, first lens 710 through sixth lens 760 may constitute first lens group G1, and seventh lens 770 and eighth lens 780 may constitute second lens group G2. The air gap between first lens group G1 and second lens group G2 may be the maximum air gap Gmax in optical imaging system 700. In other words, the air gap between sixth lens 760 and seventh lens 770 may be greater than all other air gaps between lenses in optical imaging system 700.

[0224] like Figure 20As shown in , the first lens group G1 can be moved closer to the second lens group G2 to reduce the length of the optical imaging system 700. This positional shift of the first lens group G1 can be performed selectively. For example, the first lens group G1 can be configured to provide a maximum distance to the second lens group G2 in the active mode of the optical imaging system 700 (a mode in which images can be captured), and can be configured to provide a minimum distance to the second lens group G2 in the inactive mode of the optical imaging system 700 (a mode in which images cannot be captured). The length of the optical imaging system 700 (the distance between the object-side surface of the first lens 710 and the imaging plane IP) can vary depending on the position of the first lens group G1. For example, the length TL of the optical imaging system 700 in the active mode can be greater than the length TLs of the optical imaging system 700 in the inactive mode. Therefore, the optical imaging system 700 can alleviate the problem of the camera module protruding outward from the mobile terminal device when the camera module is not in use.

[0225] The characteristics of the lenses and other elements of the optical imaging system 700 are listed in Table 13 below, and the aspheric constants of the surfaces of the lenses of the optical imaging system 700 are listed in Table 14 below.

[0226] The bold value 2.082 in the Thickness / Distance column in Table 13 is the maximum air gap Gmax, which is the air gap between the first lens group G1 and the second lens group G2, and is also the air gap between the sixth lens 760 and the seventh lens 770.

[0227] Table 13

[0228]

[0229]

[0230] Table 14

[0231]

[0232]

[0233] Figure 22 is a view showing an eighth example of the optical imaging system, Figure 23 It shows Figure 22 A view of the collapsed state of the optical imaging system shown in , and Figure 24 It shows Figure 22 A view of the aberration curves of the optical imaging system shown in .

[0234] refer to Figure 22 The optical imaging system 800 may include a first lens 810, a second lens 820, a third lens 830, a fourth lens 840, a fifth lens 850, a filter IF and an imaging surface IP.

[0235] The first lens 810 may have positive refractive power. The first lens 810 may have a convex object-side surface and a convex image-side surface. The second lens 820 may have negative refractive power. The second lens 820 may have a convex object-side surface and a concave image-side surface. The third lens 830 may have negative refractive power. The third lens 830 may have a convex object-side surface and a concave image-side surface. The fourth lens 840 may have negative refractive power. The fourth lens 840 may have a convex object-side surface and a concave image-side surface. Inflection points may be formed on the object-side surface and the image-side surface of the fourth lens 840. The fifth lens 850 may have positive refractive power. The fifth lens 850 may have a convex object-side surface and a convex image-side surface.

[0236] Optical imaging system 800 may include multiple lens groups. For example, first lens 810 and second lens 820 may constitute first lens group G1, third lens 830 may constitute second lens group G2, and fourth lens 840 and fifth lens 850 may constitute third lens group G3. The air gap between second lens group G2 and third lens group G3 may be the maximum air gap Gmax in optical imaging system 800. In other words, the air gap between third lens 830 and fourth lens 840 may be greater than all other air gaps between lenses in optical imaging system 800.

[0237] like Figure 23 As shown in FIG, first lens group G1 can be moved closer to second lens group G2, and second lens group G2 can be moved closer to third lens group G3 to reduce the length of optical imaging system 800. This positional shift of first lens group G1 and second lens group G2 can be performed selectively. For example, in an active mode (a mode in which an image can be captured) of optical imaging system 800, first lens group G1 can be positioned to provide a maximum distance to second lens group G2, and second lens group G2 can be positioned to provide a maximum distance to third lens group G3. In an inactive mode (a mode in which an image cannot be captured) of optical imaging system 800, first lens group G1 can be positioned to provide a minimum distance to second lens group G2, and second lens group G2 can be positioned to provide a minimum distance to third lens group G3. The length of optical imaging system 800 (the distance between the object-side surface of first lens 810 and imaging plane IP) can vary depending on the positions of first lens group G1 and second lens group G2. For example, the length TL of the optical imaging system 800 in the active mode may be greater than the length TLs of the optical imaging system 800 in the inactive mode. Therefore, the optical imaging system 800 may alleviate the problem of the camera module protruding outward from the mobile terminal device when the camera module is not in use.

[0238] The characteristics of the lenses and other elements of the optical imaging system 800 are listed in Table 15 below, and the aspheric constants of the surfaces of the lenses of the optical imaging system 800 are listed in Table 16 below.

[0239] The bold value 0.677 in the Thickness / Distance column in Table 15 is the air gap between the first lens group G1 and the second lens group G2, and is also the air gap between the second lens 820 and the third lens 830. The bold value 2.103 in the Thickness / Distance column in Table 15 is the maximum air gap Gmax, which is the air gap between the second lens group G2 and the third lens group G3, and is also the air gap between the third lens 830 and the fourth lens 840.

[0240] Table 15

[0241]

[0242]

[0243] Table 16

[0244]

[0245]

[0246] Figure 25 is a view showing a ninth example of the optical imaging system, Figure 26 It shows Figure 25 A view of the collapsed state of the optical imaging system shown in , and Figure 27 It shows Figure 25 A view of the aberration curves of the optical imaging system shown in .

[0247] refer to Figure 25 The optical imaging system 900 may include a first lens 910, a second lens 920, a spacer SP, a third lens 930, a fourth lens 940, a fifth lens 950, a filter IF and an imaging surface IP.

[0248] The first lens 910 may have positive refractive power. The first lens 910 may have a convex object-side surface and a convex image-side surface. The second lens 920 may have negative refractive power. The second lens 920 may have a concave object-side surface and a concave image-side surface. The third lens 930 may have negative refractive power. The third lens 930 may have a concave object-side surface and a concave image-side surface. The fourth lens 940 may have positive refractive power. The fourth lens 940 may have a concave object-side surface and a convex image-side surface. An inflection point may be formed on the object-side surface or the image-side surface of the fourth lens 940. The fifth lens 950 may have negative refractive power. The fifth lens 950 may have a concave object-side surface and a concave image-side surface.

[0249] The optical imaging system 900 may include multiple lens groups. For example, the first lens 910, the second lens 920, and the spacer SP may constitute a first lens group G1, the third lens 930 may constitute a second lens group G2, and the fourth lens 940 and the fifth lens 950 may constitute a third lens group G3. The air gap between the first lens group G1 and the second lens group G2 may be the maximum air gap Gmax in the optical imaging system 900. In other words, the air gap between the second lens 920 and the third lens 930 may be greater than all other air gaps between lenses in the optical imaging system 900.

[0250] like Figure 26 As shown in , the first lens group G1 can be moved closer to the second lens group G2 without moving the second lens group G2, thereby reducing the length of the optical imaging system 900. This positional shift of the first lens group G1 can be performed selectively. For example, the first lens group G1 can be positioned to provide a maximum distance from the second lens group G2 in the active mode of the optical imaging system 900 (a mode in which images can be captured), and can be positioned to provide a minimum distance from the second lens group G2 in the inactive mode of the optical imaging system 900 (a mode in which images cannot be captured). The length of the optical imaging system 900 (the distance between the object-side surface of the first lens 910 and the imaging plane IP) can vary depending on the positions of the first lens group G1 and the second lens group G2. For example, the length TL of the optical imaging system 900 in the active mode can be greater than the length TLs of the optical imaging system 900 in the inactive mode. Therefore, the optical imaging system 900 can alleviate the problem of the camera module protruding outward from the mobile terminal device when the camera module is not in use.

[0251] The characteristics of the lenses and other elements of the optical imaging system 900 are listed in Table 17 below, and the aspheric constants of the surfaces of the lenses of the optical imaging system 900 are listed in Table 18 below.

[0252] The sum of the bold values ​​0.433 and 2.054 in the Thickness / Distance column in Table 17, 2.487, is the maximum air gap Gmax, which is the air gap between the first lens group G1 and the second lens group G2, and is also the air gap between the second lens 920 and the third lens 930. The bold value 1.655 in the Thickness / Distance column in Table 17 is the air gap between the second lens group G2 and the third lens group G3, and is also the air gap between the third lens 930 and the fourth lens 940.

[0253] Table 17

[0254]

[0255] Table 18

[0256] Face number S2 S3 S4 S5 S7 k -0.867 0.000 0.000 -0.759 0.000 A 0.002 -0.015 -0.013 0.004 0.038 B 0.000 0.051 0.050 -0.011 -0.067 C 0.000 -0.078 -0.070 0.070 0.246 D 0.000 0.075 0.059 -0.181 -0.729 E 0.000 -0.051 -0.030 0.276 1.492 F 0.000 0.025 0.009 -0.277 -2.146 G 0.000 -0.009 0.000 0.195 2.203 H 0.000 0.002 -0.001 -0.098 -1.629 J 0.000 -0.001 0.000 0.035 0.867 L 0.000 0.000 0.000 -0.009 -0.328 M 0.000 0.000 0.000 0.002 0.086 N 0.000 0.000 0.000 0.000 -0.015 O 0.000 0.000 0.000 0.000 0.002 P 0.000 0.000 0.000 0.000 0.000 Face number S8 S9 S10 S11 S12 k 0.000 0.000 0.576 -7.562 0.000 A 0.035 0.004 -0.024 -0.062 -0.036 B 0.019 -0.011 0.022 0.035 0.015 C -0.140 0.022 -0.017 -0.006 -0.003 D 0.388 -0.035 0.012 -0.004 0.000 E -0.692 0.037 -0.009 0.004 0.001 F 0.848 -0.027 0.005 -0.002 0.000 G -0.731 0.014 -0.002 0.000 0.000 H 0.449 -0.005 0.001 0.000 0.000 J -0.196 0.001 0.000 0.000 0.000 L 0.060 0.000 0.000 0.000 0.000 M -0.013 0.000 0.000 0.000 0.000 N 0.002 0.000 0.000 0.000 0.000 O 0.000 0.000 0.000 0.000 0.000 P 0.000 0.000 0.000 0.000 0.000

[0257] Table 19 below lists the values ​​of parameters of the first to ninth examples of the above-described optical imaging system, and Table 20 below lists the values ​​of conditional expressions of the first to ninth examples of the above-described optical imaging system.

[0258] Table 19

[0259] parameter First example Second example Third example Fourth Example Fifth Example Sixth Example Example 7 Example 8 Example 9 TL 8.801 8.644 8.830 8.801 8.950 8.836 8.603 7.739 11.447 TLs 6.701 6.744 6.530 6.851 7.050 6.424 6.621 5.736 9.003 Gmax 2.200 2.000 2.400 2.050 2.000 2.512 2.082 2.103 2.487 BFL 1.352 1.538 1.081 1.345 1.340 0.990 1.075 1.431 2.896 Fno 1.91 2.30 1.80 1.89 2.31 1.89 2.31 2.45 2.47 IMGHT 6.00 6.00 6.00 6.25 6.00 6.00 6.25 3.00 3.00 f 7.237 7.584 7.049 6.952 7.661 6.992 6.660 11.421 13.216 f1 6.900 5.566 8.687 7.457 7.328 8.397 7.325 3.719 5.162 f2 -16.184 -9.859 -19.196 -24.459 -53.520 -17.561 -22.223 -8.084 -9.864 f3 -27.638 17.581 24.033 -54.434 -12.814 24.886 -66.735 -11.180 -10.112 f4 66.899 -87.472 -27.880 -14.066 -32.849 -29.748 -15.413 -6.167 18.159 f5 7.840 13.296 -12.671 5.412 15.507 -14.876 312.670 10.232 -17.731 f6 -7.011 -6.516 4.628 99.796 16.524 -144.233 5.555 - - f7 - - -5.912 -6.479 63.391 4.718 60.345 - - f8 - - - - - -5.868 -5.770 - -

[0260] Table 20

[0261] Conditional Expressions First example Second example Third example Fourth Example Fifth Example Sixth Example Example 7 Example 8 Example 9 TLs / TL 0.7614 0.7802 0.7395 0.7784 0.7877 0.7270 0.7696 0.7412 0.7865 Gmax / TL 0.2500 0.2314 0.2718 0.2329 0.2235 0.2843 0.2420 0.2717 0.2173 f / f2+f / f3 -0.7090 -0.3379 -0.0739 -0.4119 -0.7410 -0.1172 -0.3995 -2.4343 -2.6468 TL / f 1.2161 1.1398 1.2527 1.2660 1.1683 1.2637 1.2917 0.6776 0.8661 Nd2+Nd3 3.2850 3.1810 3.2150 3.3420 3.1810 3.2060 3.2060 3.2280 3.2070 BFL / f 0.1868 0.2028 0.1534 0.1935 0.1749 0.1416 0.1614 0.1253 0.2191 D12 / f 0.0287 0.0293 0.0062 0.0157 0.0309 0.0162 0.0209 0.0088 0.0045 R1 / f 0.4214 0.3389 0.4469 0.4632 0.3381 0.4505 0.4730 0.1918 0.2535

[0262] Figure 28 is included Figure 1 A cross-sectional view of a first example of a camera module of a first example of an optical imaging system is shown in FIG. Figure 29 is in a contracted state, Figure 28 A cross-sectional view of the camera module shown in FIG. Figure 30 is included Figure 28 a cross-sectional view of a first example of a mobile terminal device of a camera module shown in FIG, and Figure 31 is a camera module in a retracted state, Figure 30 A cross-sectional view of the mobile terminal device shown in FIG.

[0263] refer to Figure 28 and Figure 29 , the camera module 10 may include one of the above-mentioned optical imaging systems 100 to 700. For example, the camera module 10 may include the optical imaging system 100.

[0264] The camera module 10 may include a plurality of lens barrels BH1 and BH2. For example, the camera module 10 may include a first lens barrel BH1 and a second lens barrel BH2. The lens barrels BH1 and BH2 may be configured to accommodate the optical imaging system 100 therein. For example, the first lens barrel BH1 may accommodate the first lens group G1 of the optical imaging system 100 therein, and the second lens barrel BH2 may accommodate the second lens group G2 of the optical imaging system 100 therein. At least one of the lens barrels BH1 and BH2 may be configured to move in the optical axis direction. For example, Figure 29 As shown in , the first lens barrel BH1 can be moved toward the imaging plane in the optical axis direction, thereby reducing the length of the camera module 10. For example, the length of the camera module 10 can be reduced by the movement displacement TL-TLs of the first lens barrel BH1.

[0265] refer to Figure 30 and Figure 31 , the camera module 10 may be mounted in the mobile terminal device 20. The camera module 10 may be mounted on one surface of the mobile terminal device 20. The camera module 10 may be mounted on one surface of the mobile terminal device 20. Figure 30, or may protrude from one surface of the mobile terminal device 20 as shown in FIG. Figure 31 20. For example, the camera module 10 may protrude from one surface of the mobile terminal device 20 in the image capture mode and retract into the mobile terminal device 20 in the inactive mode. The camera module 10 may have different lengths in the image capture mode and the inactive mode. For example, the length TL of the camera module 10 in the image capture mode may be substantially equal to the thickness h of the mobile terminal device 20. Conversely, the length TLs of the camera module 10 in the inactive mode may be less than the thickness h of the mobile terminal device 20.

[0266] In the camera module 10, since the length of the camera module 10 from the object side surface of the first lens to the imaging surface increases from TLs to TL in the image capture mode, a sufficient focal length for achieving high resolution can be obtained. In addition, since the camera module 10 is completely retracted into the mobile terminal device 20 in the inactive mode, the front of the camera module 10 can be protected from external impact.

[0267] Figure 32 is included Figure 22 a cross-sectional view of a second example of a camera module of an eighth example of the optical imaging system shown in FIG. Figure 33 is in a contracted state, Figure 32 A cross-sectional view of the camera module shown in FIG. Figure 34 is included Figure 33 a cross-sectional view of a second example of a mobile terminal device of a camera module shown in FIG, and Figure 35 is a camera module in a retracted state, Figure 34 A cross-sectional view of the mobile terminal device shown in FIG.

[0268] refer to Figure 32 and Figure 33 , the camera module 12 may include one of the optical imaging system 800 and the optical imaging system 900. For example, the camera module 12 may include the optical imaging system 800.

[0269] The camera module 12 may include a plurality of lens barrels BH1, BH2, and BH3. For example, the camera module 12 may include a first lens barrel BH1, a second lens barrel BH2, and a third lens barrel BH3. The lens barrels BH1, BH2, and BH3 may be configured to accommodate the optical imaging system 800 therein. For example, the first lens barrel BH1 may accommodate the first lens group G1 of the optical imaging system 800 therein, the second lens barrel BH2 may accommodate the second lens group G2 of the optical imaging system 800 therein, and the third lens barrel BH3 may accommodate the third lens group G3 of the optical imaging system 800 therein. At least one of the lens barrels BH1, BH2, and BH3 may be configured to move in the optical axis direction. For example, as Figure 33 As shown in FIG, the first lens barrel BH1 and the second lens barrel BH2 can be moved toward the imaging surface in the optical axis direction, thereby reducing the length of the camera module 12. For example, the length of the camera module 12 can be reduced by the movement displacement TL-TLs of the first lens barrel BH1 and the second lens barrel BH2.

[0270] refer to Figure 34 and Figure 35 , the camera module 12 may be installed in the mobile terminal device 22. The camera module 12 may be installed on one surface of the mobile terminal device 22. The camera module 12 may be installed as Figure 34 22, or may protrude from one surface of the mobile terminal device 22 as shown in FIG. Figure 35 , the camera module 12 is shown retracted into the mobile terminal device 22. For example, the camera module 12 may protrude from one surface of the mobile terminal device 22 in the image capturing mode and may be retracted into the mobile terminal device 22 in the inactive mode. The camera module 12 may have different lengths in the image capturing mode and the inactive mode. For example, the length TL of the camera module 12 in the image capturing mode may be substantially equal to the thickness h of the mobile terminal device 22. Conversely, the length TLs of the camera module 12 in the inactive mode may be less than the thickness h of the mobile terminal device 22.

[0271] In the camera module 12, since the length of the camera module 12 from the object side surface of the first lens to the imaging surface increases from TLs to TL in the image capture mode, a sufficient focal length can be obtained for achieving high resolution. In particular, since the focal length of the camera module 12 can be increased by the displacement of the first lens barrel BH1 and the second lens barrel BH2, long-distance image capture or focal length adjustment can be performed. In addition, since the camera module 12 is completely retracted into the mobile terminal device 22 in the inactive mode, the front of the camera module 12 can be protected from external impact.

[0272] The described examples provide an optical imaging system having an adjustable length, a camera module including the optical imaging system, and a mobile electronic device including the camera module.

[0273] Although 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 should be interpreted in a descriptive sense only and not for purposes of limitation. The description of features or aspects in each example should be considered applicable to similar features or aspects in other examples. Suitable results may also be obtained if the described techniques are performed in a different order, and / or if the components of the described systems, architectures, devices or circuits are combined in different ways and / or replaced or supplemented with other components or their equivalents. Therefore, the scope of the present disclosure is not limited by the specific embodiments, but is limited by the claims and their equivalents, and all variations within the scope of the claims and their equivalents should be understood to be included in the present disclosure.

Claims

1. An optical imaging system, comprising: a plurality of lenses sequentially arranged along the optical axis of the optical imaging system from the object side of the optical imaging system toward the imaging plane of the optical imaging system, the plurality of lenses being separated from each other by corresponding air gaps along the optical axis between the plurality of lenses; The optical imaging system includes five, six, seven, or eight lenses having refractive power, and an image sensor having an imaging surface disposed at the imaging plane. wherein the plurality of lenses include a first lens closest to the object side of the optical imaging system among all lenses of the optical imaging system, and a second lens, a third lens, and a fourth lens arranged in ascending order along the optical axis toward the imaging plane on the image side of the first lens, wherein the first lens has positive refractive power, and the second lens has negative refractive power, and The following conditional expressions are met: 1.5mm <Gmax TL<12.0mm 0.15 <R1 / f 3.2 <Nd2+Nd3 0.12 <BFL / f<0.26 wherein Gmax is the maximum air gap among all the air gaps between the multiple lenses along the optical axis, TL is the length of the optical imaging system along the optical axis from the object side surface of the first lens to the imaging plane, R1 is the radius of curvature of the object side surface of the first lens, f is the focal length of the optical imaging system, Nd2 is the refractive index of the second lens, and Nd3 is the refractive index of the third lens, and BFL is the length along the optical axis from the image side surface of the last lens among the multiple lenses closest to the imaging plane to the imaging plane, The optical imaging system is configured to operate in an active mode or an inactive mode. The optical imaging system captures images in the active mode and does not capture images in the inactive mode. The length of the optical imaging system along the optical axis from the object side surface of the first lens to the imaging surface is smaller in the inactive mode than in the active mode. The refractive index of the fourth lens element may be greater than or equal to 1.53 and less than 1.

7. wherein the first lens has a convex object-side surface, and the second lens has a concave image-side surface, When the optical imaging system includes eight lenses, the last lens has a negative refractive power and a concave image side surface. The optical imaging system includes, from the object side toward the imaging surface, a first lens group and a second lens group, or includes the first lens group, the second lens group, and the third lens group, and has one of the following lens grouping methods: The optical imaging system includes 6, 7 or 8 lenses, and includes the first lens group and the second lens group, the second lens group includes 1 or 2 lenses, and the first lens group includes the remaining lenses; The optical imaging system includes seven lenses, and comprises a first lens group and a second lens group, wherein the first lens group includes four lenses and the second lens group includes three lenses; and The optical imaging system includes five lenses and comprises the first lens group, the second lens group, and the third lens, wherein the first lens group and the third lens group include two lenses, and the second lens group includes one lens.

2. The optical imaging system according to claim 1, wherein: The first lens has a concave image-side surface.

3. The optical imaging system according to claim 1, wherein: The plurality of lenses further includes a fifth lens disposed closest to the fourth lens along the optical axis on the image side of the fourth lens.

4. The optical imaging system according to claim 3, wherein: The following conditional expressions are met: 0.001 <D12 / f<0.04 Wherein, D12 is the air gap between the first lens and the second lens along the optical axis, and is equal to the distance from the image-side surface of the first lens to the object-side surface of the second lens along the optical axis.

5. The optical imaging system according to claim 3, wherein: The following conditional expressions are met: -3.0 <f / f2+f / f3 Wherein, f2 is the focal length of the second lens, and f3 is the focal length of the third lens.

6. The optical imaging system according to claim 1, wherein: The following conditional expressions are met: 0.6 <TL / f<1.3。

Images