Optical imaging system

Abstract

The optical imaging system includes four or more lenses arranged in sequence from the object side. Among the lenses, the front lens arranged closest to the object side has two or more reflection surfaces. Among the lenses, the last lens arranged closest to the image side has an inflection point formed on at least one of the object side surface and the image side surface.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2020-0120653 filed on September 18, 2020, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety for all purposes by reference. Technical Field

[0003] The present disclosure relates to optical imaging systems configured to image distant objects. Background Art

[0004] A small optical imaging system installed in a portable terminal device is configured to be suitable for capturing images of close-range objects. Therefore, a small-sized optical imaging system may have difficulty capturing images of distant objects. Some small optical imaging systems are configured to be suitable for capturing images of distant objects. However, due to the limitation of the installation space of the portable terminal device, it is difficult to capture images of objects set at a large distance with high resolution.

[0005] The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with respect to the present disclosure. Summary of the invention

[0006] The purpose of providing this summary is to introduce a selection of inventive concepts in a concise form, and these inventive concepts will be further described in the following detailed description. This summary is not intended to identify the key features or essential features of the subject matter claimed, nor is it intended to help determine the scope of the subject matter claimed.

[0007] In a general aspect, an optical imaging system includes four or more lenses arranged in sequence from the object side. Among the lenses, the front lens arranged closest to the object side has two or more reflection surfaces. Among the lenses, the last lens arranged closest to the image side has an inflection point formed on at least one of the object side surface and the image side surface.

[0008] The frontmost lens may have a concave image-side surface.

[0009] The final lens may have a concave object-side surface.

[0010] The final lens may have a concave image-side surface.

[0011] The frontmost lens may have positive refractive power.

[0012] The final lens may have negative refractive power.

[0013] TTL / f may be greater than 0.28 and less than 0.32, where TTL is the distance from the object side of the frontmost lens to the imaging plane, and f is the focal length of the optical imaging system.

[0014] f / f1 may be greater than 1.0 and less than 2.0, where f is the focal length of the optical imaging system and f1 is the focal length of the frontmost lens.

[0015] L1S1ER / L1S2ER may be greater than 4.30 and less than 5.80, where L1S1ER is the effective radius of the object-side surface of the front lens, and L1S2ER is the effective radius of the image-side surface of the front lens.

[0016] In another general aspect, an optical imaging system includes a first lens, a second lens having negative refractive power, a third lens, and a fourth lens, which are arranged in sequence from the object side, wherein the first lens has a first reflecting surface and a second reflecting surface, the first reflecting surface is configured to reflect light incident from the object side surface of the first lens, and the second reflecting surface is configured to reflect light reflected by the first reflecting surface to the image side surface of the first lens.

[0017] The first lens may have positive refractive power.

[0018] The third lens may have positive refractive power.

[0019] The optical imaging system may further include a fifth lens disposed on the image side of the fourth lens.

[0020] The fifth lens may have negative refractive power.

[0021] An inflection point may be formed on the object-side surface or the image-side surface of the fifth lens.

[0022] Other features and aspects will become apparent from the following detailed description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a diagram showing a first example of an optical imaging system.

[0024] Figure 2 It is shown Figure 1 Graph of the aberration curves of the optical imaging system shown.

[0025] Figure 3 is a diagram showing a second example of the optical imaging system.

[0026] Figure 4 It is shown Figure 3 Graph of the aberration curves of the optical imaging system shown.

[0027] Figure 5 is a diagram showing a third example of the optical imaging system.

[0028] Figure 6 It is shown Figure 5 Graph of the aberration curves of the optical imaging system shown.

[0029] Figure 7 is a diagram showing a fourth example of the optical imaging system.

[0030] Figure 8 It is shown Figure 7 Graph of the aberration curves of the optical imaging system shown.

[0031] Fig. 9 is a diagram showing a fifth example of the optical imaging system.

[0032] Fig.10 It is shown Fig. 9 Graph of the aberration curves of the optical imaging system shown.

[0033] Fig.11 is a diagram showing a sixth example of the optical imaging system.

[0034] Fig.12 It is shown Fig.11 Graph of the aberration curves of the optical imaging system shown.

[0035] Fig.13 is a diagram showing a seventh example of the optical imaging system.

[0036] Fig.14 It is shown Fig.13 Graph of the aberration curves of the optical imaging system shown.

[0037] Fig.15 is a diagram showing an eighth example of the optical imaging system.

[0038] Fig.16 It is shown Fig.15 Graph of the aberration curves of the optical imaging system shown.

[0039] Throughout the drawings and detailed description, the same reference numerals refer to the same elements. For purposes 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

[0040] Hereinafter, although examples of the present disclosure will be described in detail with reference to the accompanying drawings, it should be noted that the examples are not limited thereto.

[0041] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described in this application. However, various changes, modifications and equivalents of the methods, devices and / or systems described in this application will be apparent after understanding the present disclosure. For example, the order of operations described in this application is merely an example, and except for operations that must occur in a specific order, it is not limited to the order set forth in this application, but can be changed, which will be apparent after understanding the present disclosure. In addition, for greater clarity and brevity, the description of the functions and structures that will be known in the art may be omitted.

[0042] The features described in this application can be implemented in different forms and should not be understood as being limited to the examples described in this application. Rather, the examples described in this application are provided only to illustrate some of the many possible ways to implement the methods, devices and / or systems described in this application that will be apparent after understanding this disclosure.

[0043] It should be noted that in this application, the use of the word "may" with respect to examples or embodiments, for example, regarding what an example or embodiment may include or implement, means that there is at least one example or embodiment that includes or implements such features, and all examples and embodiments are not limited thereto.

[0044] Throughout the specification, when an element such as a layer, region, or substrate is described as being "on," "connected to," or "coupled to" another element, the element may be directly "on," "connected to," or "coupled to" the other element, or there may be one or more other elements 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 between the element and the other element. As used in this application, a "portion" of an element may include the entire element or less than the entire element.

[0045] As used in this application, the term "and / or" includes any one of the associated listed items and any combination of any two or more items; similarly, "at least one" includes any one of the associated listed items and any combination of any two or more items.

[0046] Although the terms "first", "second" and "third" may be used in this application to describe various members, components, regions, layers or parts, these members, components, regions, layers or parts are not limited by these terms. More specifically, these terms are only used to distinguish one member, component, region, layer or part from another member, component, region, layer or part. Therefore, without departing from the teachings of the examples described in this application, the first member, first component, first region, first layer or first part mentioned in these examples may also be referred to as the second member, second component, second region, second layer or second part.

[0047] Spatially relative terms such as "above", "higher", "below", "lower", etc. may be used in this application 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 also cover different orientations of the device in use or operation. For example, if the device in the accompanying drawings is flipped, an element described as being "above" or "higher" relative to another element will be "below" or "lower" relative to the other element. Therefore, depending on the spatial orientation of the device, the term "above" covers both orientations of "above" and "below". The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used in this application should be interpreted accordingly.

[0048] The terms used in this application are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the articles "a", "an" and "the" are intended to also include plural forms. The words "include", "comprise" and "have" indicate the presence of the features, numbers, operations, components, elements and / or their combinations, but do not exclude the presence or addition of one or more other features, numbers, operations, components, elements and / or their combinations.

[0049] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described in the present application are not limited to the specific shapes shown in the drawings, but include variations in shapes that occur during manufacturing.

[0050] Features of the examples described in this application may be combined in various ways that will be apparent after understanding the present disclosure. In addition, although the examples described in this application have various configurations, other configurations that will be apparent after understanding the present disclosure are also possible.

[0051] One aspect of the present disclosure is to provide an optical imaging system that can be mounted on a portable terminal device and can achieve a high telephoto ratio.

[0052] The optical imaging system includes a plurality of lenses arranged along an optical axis. The plurality of lenses may be spaced apart from each other by a predetermined distance along the optical axis.

[0053] For example, the optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, which are arranged in ascending numerical order along the optical axis from the object side of the optical imaging system toward the imaging plane of the optical imaging system, wherein the first lens is closest to the object side of the optical imaging system and the sixth lens is closest to the imaging plane.

[0054] In each lens, the object-side or first surface is the surface of the lens closest to the object side of the optical imaging system, and the image-side or second surface is the surface of the lens closest to the imaging plane.

[0055] Unless otherwise specified, reference to the shape of a lens surface refers to the shape of a paraxial region of the lens surface. The paraxial region of the lens surface is a central portion of the lens surface that surrounds and includes 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 approximations of sinθ≈θ, tanθ≈θ, and cosθ≈θ are valid.

[0056] In the example, the first lens refers to the lens closest to the object (or subject), and the sixth lens refers to the lens closest to the imaging plane (or image sensor). In the example, the units of the radius of curvature, thickness, TTL (the distance from the object side of the first lens (or the front lens) to the imaging plane), IMGHT (half the diagonal length of the imaging plane), and focal length are expressed in millimeters (mm). The thickness of the lens, the gap between the lenses, and TTL refer to the distance of the lenses on the optical axis. In addition, in the description of the shape of the lens, a configuration in which one face is convex indicates that the optical axis area of ​​the face is convex, and a configuration in which one face is concave indicates that the optical axis area of ​​the face is concave. Therefore, even when one face of the lens is described as convex, the edge of the lens may be concave. Similarly, even when one face of the lens is described as concave, the edge of the lens may be convex.

[0057] The optical imaging system according to the example can be configured to be miniaturized and to capture images of distant objects. For example, the optical imaging system may include a lens having a plurality of reflective surfaces and a lens on which an inflection point is formed. The lens having a reflective surface may be arranged closest to the object side (hereinafter referred to as the frontmost lens), and the lens on which an inflection point is formed may be arranged closest to the imaging surface (hereinafter referred to as the last lens).

[0058] The front lens may have a refractive power. For example, the front lens may have a positive refractive power. A surface of the front lens may be concave. For example, the front lens may have a concave image-side surface. The last lens may have a refractive power. For example, the last lens may have a negative refractive power. A surface of the last lens may be concave. For example, the last lens may have a concave object-side surface. As another example, the last lens may have a concave image-side surface. An inflection point may be formed on the last lens. For example, an inflection point may be formed on at least one of the object-side surface and the image-side surface of the last lens.

[0059] According to another example, the optical imaging system may include four or five lenses arranged in sequence from the object side to the imaging surface. For example, the optical imaging system may include a first lens, a second lens, a third lens, and a fourth lens arranged in sequence, or a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged in sequence. The first lens to the fourth lens or the first lens to the fifth lens may be arranged at a predetermined interval. For example, a predetermined interval may be formed between the image side of the first lens and the object side of the second lens.

[0060] The first lens may have a 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. The first lens may have both a spherical surface and an aspherical surface. For example, the object side surface of the first lens may be a spherical surface, and the image side surface of the first lens may be an aspherical surface. The first lens may be formed of a material having high light transmittance and excellent processability. For example, a plastic material may be used to manufacture the first lens. However, the material of the first lens is not limited to a plastic material. For example, a glass material may be used to manufacture the first lens. The first lens may have a predetermined refractive index. For example, the refractive index of the first lens may be greater than 1.6 to less than 1.8. The first lens may have a predetermined focal length. For example, the focal length of the first lens may be selected within the range of 14 mm to 22 mm.

[0061] The first lens may include two or more reflective surfaces. For example, the first lens may have a first reflective surface that reflects light incident from the object side surface of the first lens and a second reflective surface that reflects light reflected by the first reflective surface to the image side surface of the first lens. The first reflective surface and the second reflective surface may be formed as curved surfaces. For example, the first reflective surface may be concave, and the second reflective surface may be convex. The first reflective surface and the second reflective surface may be formed in a specific area of ​​the first lens. For example, the first reflective surface may be formed in an edge area of ​​the image side surface of the first lens excluding the optical axis area or the paraxial area, and the second reflective surface may be formed in the optical axis area or the paraxial area of ​​the object side surface of the first lens.

[0062] The second lens may have a refractive power. For example, the second lens may have a negative refractive power. One surface of the second lens may be concave. For example, the second lens may have a concave object side surface. The second lens may have an aspherical surface. For example, the object side surface and the image side surface of the second lens may be aspherical surfaces. The second lens may be formed of a material having high light transmittance and excellent processability. For example, a plastic material may be used to manufacture the second lens. However, the material of the second lens is not limited to plastic material. For example, a glass material may be used to manufacture the second lens. The second lens may have a predetermined refractive index. For example, the refractive index of the second lens may be greater than 1.6 to less than 1.7. The second lens may have a predetermined focal length. For example, the focal length of the second lens may be selected within the range of -16 mm to -3.0 mm.

[0063] The third lens may have a refractive power. For example, the third lens may have a positive refractive power. One surface of the third lens may be convex. For example, the third lens may have a convex image side surface. The third lens may have an aspherical surface. For example, the object side surface and the image side surface of the third lens may be aspherical surfaces. The third lens may be formed of a material having high light transmittance and excellent processability. For example, the third lens may be formed of a plastic material. However, the material of the third lens is not limited to plastic materials. For example, the third lens may be manufactured using a glass material. The third lens may have a predetermined refractive index. For example, the refractive index of the third lens may be greater than 1.5 to less than 1.65. The third lens may have a predetermined focal length. For example, the focal length of the third lens may be selected within the range of 4.0 mm to 8.0 mm.

[0064] The fourth lens may have a refractive power. For example, the fourth lens may have a positive refractive power or a negative refractive power. The fourth lens has a concave shape. For example, the fourth lens may have a concave object side surface or image side surface. The fourth lens may have an aspherical surface. For example, the object side surface and the image side surface of the fourth lens may be aspherical surfaces. An inflection point may be formed on the fourth lens. For example, an inflection point may be formed on at least one of the object side surface and the image side surface of the fourth lens. The fourth lens may be formed of a material having high light transmittance and excellent processability. For example, the fourth lens may be manufactured using a plastic material. However, the material of the fourth lens is not limited to the plastic material. For example, the fourth lens may be manufactured using a glass material. The fourth lens may have a predetermined refractive index. For example, the refractive index of the fourth lens may be greater than 1.5 to less than 1.6. The fourth lens may have a predetermined focal length. For example, the focal length of the fourth lens having a positive refractive power may be selected in the range of 30 mm to 120 mm, and the focal length of the fourth lens having a negative refractive power may be selected in the range of -500 mm to -2.0 mm.

[0065] If necessary, the optical imaging system may further include a fifth lens disposed on the image side surface of the fourth lens. The fifth lens optionally included may have the following features.

[0066] The fifth lens may have a refractive power. For example, the fifth lens may have a negative refractive power. One surface of the fifth lens may be concave. For example, the fifth lens may have a concave object side surface. The fifth lens may have an aspherical surface. For example, the object side surface and the image side surface of the fifth lens may be aspherical surfaces. An inflection point may be formed on the fifth lens. For example, an inflection point may be formed on at least one of the object side surface and the image side surface of the fifth lens. The fifth lens may be formed of a material having high light transmittance and excellent processability. For example, the fifth lens may be manufactured using a plastic material. However, the material of the fifth lens is not limited to a plastic material. For example, the fifth lens may be manufactured using a glass material. The fifth lens may have a predetermined refractive index. For example, the refractive index of the fifth lens may be greater than 1.5 to less than 1.6. The fifth lens may have a predetermined focal length. For example, the focal length of the fifth lens may be selected within a range of -5.0 mm to -2.0 mm.

[0067] As described above, each of the first to fifth lenses may have an aspherical surface. For example, at least one surface of the first to fifth lenses may be aspherical. The aspherical surface of each of the first to fifth lenses may be represented by the following equation 1:

[0068] (Equation 1)

[0069]

[0070] In Equation 1, "c" is the inverse of the radius of curvature of each lens, "k" is the cone constant, "r" is the distance from a point on the aspherical surface of the lens to the optical axis, "A" to "H" and "J" are aspherical constants, and "Z" (or SAG) is the height from a point on the aspherical surface to the vertex of the aspherical surface in the optical axis direction.

[0071] The optical imaging system may further include a stop, which may be disposed in front of the first lens, between the first lens and the second lens, or the like.

[0072] The optical imaging system may further include a filter. The filter may block some wavelengths of incident light from being incident through the first lens to the fourth lens. For example, the filter may block infrared wavelengths of the incident light.

[0073] The optical imaging system may further include an image sensor. The image sensor may provide an imaging surface on which light refracted by the lens may be imaged. For example, a surface of the image sensor may form the imaging surface. The image sensor may be configured to achieve high resolution. The imaging surface of the image sensor may have a predetermined size.

[0074] The optical imaging system can be configured to increase the optical path length without increasing the total length of the optical imaging system. For example, the first lens can form an optical path with a significant length. For example, the first lens can form a first optical path connecting the object side of the first lens to the first reflecting surface, a second optical path connecting the first reflecting surface to the second reflecting surface, and a third optical path connecting the second reflecting surface to the imaging surface of the first lens. The optical path formed by the first lens can be longer than the distance from the object side of the first lens to the imaging surface.

[0075] The optical imaging system configured as described above can increase the telephoto ratio without increasing the number of lenses or the distance between the lenses. Therefore, the optical imaging system can be easily installed in a small camera module and a thin portable terminal device with a small thickness.

[0076] The optical imaging system according to the example can satisfy one or more of the following conditional expressions.

[0077] 0.28 < TTL / f < 0.32

[0078] 1.0 < f / f1 < 2.0

[0079] 0 < V1 - V2 < 30

[0080] 3.14 < Nd2 + Nd3 < 3.40

[0081] 0.02 < BFL / f < 0.25

[0082] 0.001 < D12 / f < 0.04

[0083] 2.3 < f-number

[0084] In the above conditional expressions, TTL is the distance from the object side of the first lens (or the frontmost lens) to the imaging surface of the optical imaging system, f is the focal length of the optical imaging system, f1 is the focal length of the first lens (or the frontmost lens), V1 is the Abbe number of the first lens, V2 is the Abbe number of the second lens. Nd2 is the refractive index of the second lens, Nd3 is the refractive index of the third lens, and BFL is the distance from the image side of the lens closest to the imaging surface to the imaging surface, and D12 is the distance from the image side of the first lens to the object side of the second lens.

[0085] The optical imaging system can also satisfy one or more of the following conditional expressions.

[0086] 4.30 < L1S1ER / L1S2ER < 5.80

[0087] 1.1 < L1TL / TTL < 1.3

[0088] In the above conditional expressions, L1S1ER is the effective radius of the object side surface of the first lens (or the front lens), L1S2ER is the effective radius of the image side surface of the first lens (or the front lens), and L1TL is the sum of the distance from the object side surface of the first lens (or the front lens) to the first reflection surface, the distance from the first reflection surface to the second reflection surface, and the distance from the second reflection surface to the imaging surface of the optical imaging system.

[0089] In the following description, various examples of optical imaging systems will be described.

[0090] In the following, reference will be made to Figure 1 An optical imaging system 100 according to a first example is described.

[0091] The optical imaging system 100 may include a plurality of lenses, each of which has a refractive power. For example, the optical imaging system 100 may include a first lens 110, a second lens 120, a third lens 130, and a fourth lens 140. The first lens 110 to the fourth lens 140 may be sequentially spaced from the object side.

[0092] The first lens 110 may have positive refractive power and may have a convex object-side surface and a concave image-side surface around (but not including) the paraxial region. The second lens 120 may have negative refractive power and may have a concave object-side surface and a convex image-side surface. The third lens 130 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The fourth lens 140 may have negative refractive power and may have a concave 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 140.

[0093] The first lens 110 is configured to have an optical path having a significant length (as used herein, a significant length refers to a relatively long length). For example, the optical path of the first lens 110 may include a first optical path connecting the first reflection surface S3 from the object side surface S2, a second optical path connecting the second reflection surface S4 from the first reflection surface S3, and a third optical path connecting the image side surface S5 from the second reflection surface S4. The optical path having a significant length as described herein may be longer relative to a comparative optical path directly connecting the image side surface from the object side surface. Therefore, the optical imaging system 100 according to the first example can ensure a significant optical path required for long-distance image shooting through the first lens 110.

[0094] The optical imaging system 100 may include an optical filter IF. For example, the optical filter IF may be disposed between the fourth lens 140 and the imaging plane IP. The optical filter IF may be configured to block infrared light.

[0095] The optical imaging system 100 according to the first example presents Figure 2The lens characteristics of the optical imaging system 100 according to the first example are listed in Table 1.

[0096] Table 1

[0097] Face number mark Radius of curvature Thickness / distance Refractive Index Abbe number Effective radius S1 Aperture infinity 0 S2 First lens 692.186 3.253 1.743 49.200 3.071 S3 -8.151 -2.907 3.222 S4 -2.796 2.521 1.172 S5 5.600 0.650 1.202 S6 Second lens -4.371 0.250 1.614 25.900 1.240 S7 -13.653 0.226 1.336 S8 The third lens -15.480 0.418 1.535 56.100 1.380 S9 -2.224 1.156 1.506 S10 The fourth lens -1.938 0.380 1.535 56.100 2.202 S11 8.074 0.052 2.415 S12 Optical Filters infinity 0.110 1.518 64.166 2.563 S13 infinity 0.894 2.582 S14 Imaging surface infinity -0.004 2.825

[0098] The aspherical characteristics of the optical imaging system 100 according to the first example are listed in Table 2.

[0099] Table 2

[0100]

[0101]

[0102] In the following, reference will be made to Figure 3 An optical imaging system 200 according to a second example is described.

[0103] The optical imaging system 200 may include a plurality of lenses, each of which has a refractive power. For example, the optical imaging system 200 may include a first lens 210, a second lens 220, a third lens 230, and a fourth lens 240. The first lens 210 to the fourth lens 240 may be sequentially spaced from the object side.

[0104] The first lens 210 may have positive refractive power and may have a convex object-side surface and a concave image-side surface around (but not including) the paraxial region. The second lens 220 may have negative refractive power and may have a concave object-side surface and a convex image-side surface. The third lens 230 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The fourth lens 240 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. An inflection point may be formed on the object-side surface and the image-side surface of the fourth lens 240.

[0105] The first lens 210 may be configured to have an optical path having a significant length. For example, the optical path of the first lens 210 may include a first optical path connecting the first reflection surface S3 from the object side surface S2, a second optical path connecting the second reflection surface S4 from the first reflection surface S3, and a third optical path connecting the image side surface S5 from the second reflection surface S4. Therefore, the optical imaging system 200 according to the second example can ensure a significant optical path required for long-distance image shooting through the first lens 210.

[0106] The optical imaging system 200 may include an optical filter IF. For example, the optical filter IF may be disposed between the fourth lens 240 and the imaging plane IP. The optical filter IF may be configured to block infrared light.

[0107] The optical imaging system 200 according to the second example presents Figure 4The lens characteristics of the optical imaging system 200 according to the second example are listed in Table 3.

[0108] Table 3

[0109] Face number mark Radius of curvature Thickness / distance Refractive Index Abbe number Effective radius S1 Aperture infinity 0.000 S2 First lens 764.576 3.253 1.640 23.500 3.285 S3 -8.137 -2.907 3.436 S4 -2.797 2.521 1.257 S5 5.572 0.650 1.231 S6 Second lens -3.931 0.250 1.661 20.400 1.250 S7 -10.212 0.194 1.358 S8 The third lens -14.097 0.446 1.535 56.100 1.407 S9 -2.265 1.160 1.530 S10 The fourth lens -1.968 0.380 1.535 56.100 2.203 S11 8.600 0.052 2.445 S12 Optical Filters infinity 0.110 1.518 64.166 2.558 S13 infinity 0.879 2.576 S14 Imaging surface infinity 0.011 2.823

[0110] The aspherical characteristics of the optical imaging system 200 according to the second example are listed in Table 4.

[0111] Table 4

[0112] Face number S3 S4 S5 S6 S7 K -1.98583 -4.50680 17.54674 5.83849 9.60597 A -0.00019 -0.00808 0.00669 -0.01627 -0.12053 B 0.00000 0.00235 -0.02391 0.09116 0.18739 C 0.00000 0.00009 -0.00098 -0.61202 -0.51671 D 0.00000 -0.00058 -0.00311 1.60562 1.00110 E 0.00000 0.00026 0.00000 -2.38292 -1.13415 F 0.00000 0.00000 0.00000 2.11622 0.76623 G 0.00000 -0.00003 0.00000 -1.10589 -0.29980 H 0.00000 -0.00001 0.00000 0.31343 0.06218 J 0.00000 0.00001 0.00000 -0.03703 -0.00530 Face number S8 S9 S10 S11 K -99.00000 -3.70427 -1.30044 -1.30044 A -0.22871 -0.08327 0.00492 0.00492 B 0.20221 -0.03409 -0.05881 -0.05881 C -0.25100 0.18191 0.09468 0.09468 D 0.38724 -0.25257 -0.06756 -0.06756 E -0.34703 0.23885 0.02811 0.02811 F 0.16375 -0.15162 -0.00713 -0.00713 G -0.03537 0.06033 0.00108 0.00108 H 0.00107 -0.01351 -0.00009 -0.00009 J 0.00047 0.00129 0.00000 0.00000

[0113] In the following, reference will be made to Figure 5 An optical imaging system 300 according to a third example is described.

[0114] The optical imaging system 300 may include a plurality of lenses having refractive power. For example, the optical imaging system 300 may include a first lens 310, a second lens 320, a third lens 330, and a fourth lens 340. The first lens 310 to the fourth lens 340 may be sequentially spaced from the object side.

[0115] The first lens 310 may have positive refractive power and may have a convex object-side surface and a concave image-side surface around (but not including) the paraxial region. The second lens 320 may have negative refractive power and may have a concave object-side surface and a convex image-side surface. The third lens 330 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The fourth lens 340 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. An inflection point may be formed on the object-side surface and the image-side surface of the fourth lens 340.

[0116] The first lens 310 may be configured to have an optical path having a significant length. For example, the optical path of the first lens 310 may include a first optical path connecting the first reflection surface S3 from the object side surface S2, a second optical path connecting the second reflection surface S4 from the first reflection surface S3, and a third optical path connecting the image side surface S5 from the second reflection surface S4. Therefore, the optical imaging system 300 according to the third example can ensure a significant optical path required for long-distance image shooting through the first lens 310.

[0117] The optical imaging system 300 may include an optical filter IF. For example, the optical filter IF may be disposed between the fourth lens 340 and the imaging plane IP. The optical filter IF may be configured to block infrared light.

[0118] The optical imaging system 300 according to the third example presents Figure 6 The lens characteristics of the optical imaging system 300 according to the third example are listed in Table 5.

[0119] Table 5

[0120] Face number mark Radius of curvature Thickness / distance Refractive Index Abbe number Effective radius S1 Aperture infinity 0.000 S2 First lens 781.855 3.253 1.614 25.900 3.280 S3 -8.143 -2.907 3.435 S4 -2.805 2.521 1.261 S5 5.584 0.653 1.229 S6 Second lens -3.906 0.252 1.640 23.500 1.250 S7 -9.202 0.195 1.358 S8 The third lens -12.984 0.445 1.535 56.100 1.409 S9 -2.270 1.156 1.532 S10 The fourth lens -1.966 0.380 1.535 56.100 2.192 S11 7.984 0.052 2.439 S12 Optical Filters infinity 0.110 1.518 64.166 2.548 S13 infinity 0.879 2.566 S14 Imaging surface infinity 0.011 2.823

[0121] The aspherical characteristics of the optical imaging system 300 according to the third example are listed in Table 6.

[0122] Table 6

[0123] Face number S3 S4 S5 S6 S7 K -1.98583 -4.50680 17.54674 5.83849 9.60597 A -0.00019 -0.00808 0.00669 -0.01627 -0.12053 B 0.00000 0.00235 -0.02391 0.09116 0.18739 C 0.00000 0.00009 -0.00098 -0.61202 -0.51671 D 0.00000 -0.00058 -0.00311 1.60562 1.00110 E 0.00000 0.00026 0.00000 -2.38292 -1.13415 F 0.00000 0.00000 0.00000 2.11622 0.76623 G 0.00000 -0.00003 0.00000 -1.10589 -0.29980 H 0.00000 -0.00001 0.00000 0.31343 0.06218 J 0.00000 0.00001 0.00000 -0.03703 -0.00530 Face number S8 S9 S10 S11 K -99.00000 -3.70427 -1.30044 -19.44223 A -0.22871 -0.08327 0.00492 -0.03661 B 0.20221 -0.03409 -0.05881 -0.00150 C -0.25100 0.18191 0.09468 0.00555 D 0.38724 -0.25257 -0.06756 -0.00161 E -0.34703 0.23885 0.02811 -0.00013 F 0.16375 -0.15162 -0.00713 0.00017 G -0.03537 0.06033 0.00108 -0.00004 H 0.00107 -0.01351 -0.00009 0.00000 J 0.00047 0.00129 0.00000 0.00000

[0124] In the following, reference will be made to Figure 7 An optical imaging system 400 according to a fourth example is described.

[0125] The optical imaging system 400 may include a plurality of lenses, each of which has a refractive power. For example, the optical imaging system 400 may include a first lens 410, a second lens 420, a third lens 430, a fourth lens 440, and a fifth lens 450. The first lens 410 to the fifth lens 450 may be sequentially spaced from the object side.

[0126] The first lens 410 may have positive refractive power and may have a concave object-side surface and a concave image-side surface around (but not including) the paraxial region. The second lens 420 may have negative refractive power and may have a concave object-side surface and a convex image-side surface. The third lens 430 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The fourth lens 440 may have negative refractive power and may have a concave object-side surface and a convex image-side surface. The fifth lens 450 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. An inflection point may be formed on the object-side surface and the image-side surface of the fifth lens 450.

[0127] The first lens 410 may be configured to have an optical path having a significant length. For example, the optical path of the first lens 410 may include a first optical path connecting the first reflection surface S3 from the object side surface S2, a second optical path connecting the second reflection surface S4 from the first reflection surface S3, and a third optical path connecting the image side surface S5 from the second reflection surface S4. Therefore, the optical imaging system 400 according to the fourth example can ensure a significant optical path required for long-distance image shooting through the first lens 410.

[0128] The optical imaging system 400 may include an optical filter IF. For example, the optical filter IF may be disposed between the fifth lens 450 and the imaging plane IP. The optical filter IF may be configured to block infrared light.

[0129] According to the fourth example, the optical imaging system 400 presents Figure 8 The aberration characteristics shown. The lens characteristics of the optical imaging system 400 according to the fourth example are listed in Table 7.

[0130] Table 7

[0131] Face number mark Radius of curvature Thickness / distance Refractive Index Abbe number Effective radius S1 Aperture infinity 0.000 S2 First lens -2601.669 3.400 1.743 49.200 2.932 S3 -8.110 -2.902 3.118 S4 -2.810 2.444 1.166 S5 9.379 0.650 1.180 S6 Second lens -4.404 0.250 1.640 23.500 1.206 S7 -9.176 0.445 1.319 S8 The third lens -2.958 0.408 1.544 56.100 1.390 S9 -1.750 0.423 1.485 S10 The fourth lens -2.165 0.400 1.535 56.100 1.764 S11 -2.325 0.218 1.962 S12 Fifth lens -2.016 0.250 1.535 56.100 2.160 S13 6.105 0.275 2.434 S14 Optical Filters infinity 0.110 1.518 64.166 2.647 S15 infinity 0.630 2.664 S16 Imaging surface infinity 0.000 2.821

[0132] The aspherical characteristics of the optical imaging system 400 according to the fourth example are listed in Table 8.

[0133] Table 8

[0134]

[0135]

[0136] In the following, reference will be made to Fig. 9 An optical imaging system 500 according to a fifth example is described.

[0137] The optical imaging system 500 may include a plurality of lenses, each of which has a refractive power. For example, the optical imaging system 500 may include a first lens 510, a second lens 520, a third lens 530, a fourth lens 540, and a fifth lens 550. The first lens 510 to the fifth lens 550 may be sequentially spaced from the object side.

[0138] The first lens 510 may have positive refractive power and may have a concave object side surface and a concave image side surface around (but not including) the paraxial region. The second lens 520 may have negative refractive power and may have a concave object side surface and a convex image side surface. The third lens 530 may have positive refractive power and may have a concave object side surface and a convex image side surface. The fourth lens 540 may have positive refractive power and may have a concave object side surface and a convex image side surface. The fifth lens 550 may have negative refractive power and may have a concave object side surface and a concave image side surface. An inflection point may be formed on the object side surface and the image side surface of the fifth lens 550.

[0139] The first lens 510 may be configured to have an optical path having a significant length. For example, the optical path of the first lens 510 may include a first optical path connecting the first reflection surface S3 from the object side surface S2, a second optical path connecting the second reflection surface S4 from the first reflection surface S3, and a third optical path connecting the image side surface S5 from the second reflection surface S4. Therefore, the optical imaging system 500 according to the fifth example can ensure a significant optical path required for long-distance image shooting through the first lens 510.

[0140] The optical imaging system 500 may include an optical filter IF. For example, the optical filter IF may be disposed between the fifth lens 550 and the imaging plane IP. The optical filter IF may be configured to block infrared light.

[0141] The optical imaging system 500 according to the fifth example presents Fig.10The aberration characteristics shown. The lens characteristics of the optical imaging system 500 according to the fifth example are listed in Table 9.

[0142] Table 9

[0143] Face number mark Radius of curvature Thickness / distance Refractive Index Abbe number Effective radius S1 Aperture infinity 0.000 S2 First lens -14288.941 3.400 1.743 49.200 2.863 S3 -8.124 -2.902 3.055 S4 -2.819 2.444 1.153 S5 8.997 0.650 1.185 S6 Second lens -4.501 0.250 1.640 23.500 1.227 S7 -8.838 0.427 1.352 S8 The third lens -3.146 0.408 1.535 56.100 1.437 S9 -1.810 0.085 1.532 S10 The fourth lens -9.368 0.400 1.535 56.100 1.781 S11 -8.227 0.430 2.000 S12 Fifth lens -1.971 0.300 1.535 56.100 2.177 S13 6.252 0.109 2.436 S14 Optical Filters infinity 0.110 1.518 64.166 2.576 S15 infinity 0.901 2.594 S16 Imaging surface infinity -0.011 2.821

[0144] The aspherical characteristics of the optical imaging system 500 according to the fifth example are listed in Table 10.

[0145] Table 10

[0146]

[0147]

[0148] In the following, reference will be made to Fig.11 An optical imaging system 600 according to a sixth example is described.

[0149] The optical imaging system 600 may include a plurality of lenses having refractive power. For example, the optical imaging system 600 may include a first lens 610, a second lens 620, a third lens 630, a fourth lens 640, and a fifth lens 650. The first lens 610 to the fifth lens 650 may be sequentially spaced from the object side.

[0150] The first lens 610 may have positive refractive power and may have a convex object side surface and a concave image side surface around (but not including) the paraxial region. The second lens 620 may have negative refractive power and may have a concave object side surface and a concave image side surface. The third lens 630 may have positive refractive power and may have a convex object side surface and a convex image side surface. The fourth lens 640 may have positive refractive power and may have a convex object side surface and a concave image side surface. The fifth lens 650 may have negative refractive power and may have a concave object side surface and a concave image side surface. Inflection points may be formed on the fourth lens 640 and the fifth lens 650.

[0151] The first lens 610 may be configured to have an optical path having a significant length. For example, the optical path of the first lens 610 may include a first optical path connecting the first reflection surface S3 from the object side surface S2, a second optical path connecting the second reflection surface S4 from the first reflection surface S3, and a third optical path connecting the image side surface S5 from the second reflection surface S4. Therefore, the optical imaging system 600 according to the sixth example can ensure a significant optical path required for long-distance image shooting through the first lens 610.

[0152] The optical imaging system 600 may include an optical filter IF. For example, the optical filter IF may be disposed between the fifth lens 650 and the imaging plane IP. The optical filter IF may be configured to block infrared light.

[0153] The optical imaging system 600 according to the sixth example presents Fig.12 The aberration characteristics shown. The lens characteristics of the optical imaging system 600 according to the sixth example are listed in Table 11.

[0154] Table 11

[0155]

[0156]

[0157] The aspherical characteristics of the optical imaging system 600 according to the sixth example are listed in Table 12.

[0158] Table 12

[0159] Face number S3 S4 S5 S6 S7 S8 K -1.99875 -4.80242 35.87110 -40.39823 -90.00000 -59.63001 A -0.00018 -0.00691 0.03256 0.02425 -0.10397 -0.37034 B 0.00000 0.00205 -0.03081 -0.03429 0.44502 0.52491 C 0.00000 0.00005 0.00576 0.15388 -1.17687 -0.47873 D 0.00000 -0.00052 -0.00411 -0.89775 1.61980 0.12682 E 0.00000 0.00021 0.00000 2.10329 -1.32130 0.04161 F 0.00000 0.00001 0.00000 -2.60236 0.65241 0.10478 G 0.00000 0.00000 0.00000 1.80899 -0.17121 -0.15853 H 0.00000 0.00000 0.00000 -0.67167 0.01291 0.07051 J 0.00000 0.00000 0.00000 0.10393 0.00197 -0.01076 Face number S9 S10 S11 S12 S13 K 1.48957 9.33549 25.40869 0.33221 -45.29881 A -0.16402 0.02588 0.07621 -0.03800 -1.50400 B 0.17148 -0.03984 -0.14136 0.04862 1.81138 C 0.13845 0.10035 0.12655 -0.03694 3.42711 D -0.41214 -0.12547 -0.07244 0.02672 -14.89607 E 0.40173 0.08408 0.02845 -0.01386 19.82343 F -0.21183 -0.03333 -0.00790 0.00448 -12.74281 G 0.06343 0.00778 0.00147 -0.00085 5.48973 H -0.01009 -0.00098 -0.00016 0.00008 -2.87119 J 0.00066 0.00005 0.00001 0.00000 0.96459

[0160] In the following, reference will be made to Fig.13 An optical imaging system 700 according to a seventh example is described.

[0161] The optical imaging system 700 may include a plurality of lenses having refractive power. For example, the optical imaging system 700 may include a first lens 710, a second lens 720, a third lens 730, a fourth lens 740, and a fifth lens 750. The first lens 710 to the fifth lens 750 may be sequentially spaced from the object side.

[0162] The first lens 710 may have positive refractive power and may have a convex object side surface and a concave image side surface around (but not including) the paraxial region. The second lens 720 may have negative refractive power and may have a concave object side surface and a convex image side surface. The third lens 730 may have positive refractive power and may have a concave object side surface and a convex image side surface. The fourth lens 740 may have positive refractive power and may have a convex object side surface and a concave image side surface. The fifth lens 750 may have negative refractive power and may have a concave object side surface and a concave image side surface. Inflection points may be formed on the fourth lens 740 and the fifth lens 750.

[0163] The first lens 710 may be configured to have an optical path having a significant length. For example, the optical path of the first lens 710 may include a first optical path connecting the first reflection surface S3 from the object side surface S2, a second optical path connecting the second reflection surface S4 from the first reflection surface S3, and a third optical path connecting the image side surface S5 from the second reflection surface S4. Therefore, the optical imaging system 700 according to the seventh example can ensure a significant optical path required for long-distance image shooting through the first lens 710.

[0164] The optical imaging system 700 may include an optical filter IF. For example, the optical filter IF may be disposed between the fifth lens 750 and the imaging plane IP. The optical filter IF may be configured to block infrared light.

[0165] The optical imaging system 700 according to the seventh example presents Fig.14 The aberration characteristics shown. The lens characteristics of the optical imaging system 700 according to the seventh example are listed in Table 13.

[0166] Table 13

[0167] Face number mark Radius of curvature Thickness / distance Refractive Index Abbe number Effective radius S1 Aperture infinity 0.000 S2 First lens 827.377 3.180 1.743 49.200 3.100 S3 -8.220 -2.902 3.246 S4 -2.917 2.444 1.210 S5 8.255 0.650 1.199 S6 Second lens -4.169 0.250 1.614 25.900 1.223 S7 -160.098 0.362 1.310 S8 The third lens -23.446 0.350 1.567 38.000 1.365 S9 -2.905 0.085 1.559 S10 The fourth lens 9.436 0.610 1.535 56.100 1.934 S11 11.805 0.429 2.133 S12 Fifth lens -3.851 0.400 1.535 56.100 2.327 S13 3.745 0.142 2.532 S14 Optical Filters infinity 0.110 1.518 64.166 2.622 S15 infinity 0.905 2.636 S16 Imaging surface infinity -0.015 2.824

[0168] The aspheric characteristics of the optical imaging system 700 according to the seventh example are listed in Table 14.

[0169] Table 14

[0170] Face number S3 S4 S5 S6 S7 S8 K -2.00306 -4.75395 35.98520 -37.86621 99.00000 -99.00000 A -0.00018 -0.00701 0.02570 -0.00934 -0.16104 -0.44232 B 0.00000 0.00207 -0.02810 0.16784 0.79293 0.84790 C 0.00000 0.00007 0.00795 -0.42657 -2.20181 -1.22404 D 0.00000 -0.00054 -0.00404 0.19237 3.55937 1.03922 E 0.00000 0.00021 0.00000 0.61969 -3.80196 -0.59170 F 0.00000 0.00001 0.00000 -1.17921 2.74276 0.38655 G 0.00000 0.00000 0.00000 0.94713 -1.25114 -0.25884 H 0.00000 0.00000 0.00000 -0.38321 0.31843 0.10067 J 0.00000 0.00000 0.00000 0.06332 -0.03411 -0.01552 Face number S9 S10 S11 S12 S13 K 1.01541 2.24456 26.68866 0.30754 -36.89762 A -0.15489 0.06794 0.04654 -0.03208 -0.04202 B 0.18993 -0.22508 -0.10255 0.04243 -0.00519 C -0.01816 0.35062 0.08790 -0.02398 0.01755 D -0.20018 -0.31351 -0.05548 0.01229 -0.00916 E 0.33152 0.16864 0.02498 -0.00506 0.00275 F -0.26164 -0.05631 -0.00796 0.00136 -0.00057 G 0.11065 0.01144 0.00171 -0.00021 0.00008 H -0.02409 -0.00129 -0.00022 0.00002 -0.00001 J 0.00213 0.00006 0.00001 0.00000 0.0

[0171] In the following, reference will be made to Fig.15 An optical imaging system 800 according to an eighth example is described.

[0172] The optical imaging system 800 may include a plurality of lenses, each of which has a refractive power. For example, the optical imaging system 800 may include a first lens 810, a second lens 820, a third lens 830, a fourth lens 840, and a fifth lens 850. The first lens 810 to the fifth lens 850 may be sequentially spaced from the object side.

[0173] The first lens 810 may have positive refractive power and may have a convex object side surface and a concave image side surface around (but not including) the paraxial region. The second lens 820 may have negative refractive power and may have a concave object side surface and a concave image side surface. The third lens 830 may have positive refractive power and may have a convex object side surface and a convex image side surface. The fourth lens 840 may have positive refractive power and may have a convex object side surface and a concave image side surface. The fifth lens 850 may have negative refractive power and may have a concave object side surface and a concave image side surface. Inflection points may be formed on the fourth lens 840 and the fifth lens 850.

[0174] The first lens 810 may be configured to have an optical path having a significant length. For example, the optical path of the first lens 810 may include a first optical path connecting the first reflection surface S3 from the object side surface S2, a second optical path connecting the second reflection surface S4 from the first reflection surface S3, and a third optical path connecting the image side surface S5 from the second reflection surface S4. Therefore, the optical imaging system 800 according to the eighth example can ensure a significant optical path required for long-distance image shooting through the first lens 810.

[0175] The optical imaging system 800 may include an optical filter IF. For example, the optical filter IF may be disposed between the fifth lens 850 and the imaging plane IP. The optical filter IF may be configured to block infrared light.

[0176] The optical imaging system 800 according to the eighth example presents Fig.16 The aberration characteristics shown. The lens characteristics of the optical imaging system 800 according to the eighth example are listed in Table 15.

[0177] Table 15

[0178] Face number mark Radius of curvature Thickness / distance Refractive Index Abbe number Effective radius S1 Aperture infinity 0.000 S2 First lens 766.550 3.180 1.661 20.400 3.100 S3 -8.233 -2.902 3.246 S4 -2.953 2.444 1.210 S5 7.818 0.650 1.199 S6 Second lens -4.824 0.250 1.680 18.400 1.223 S7 4.769 0.221 1.310 S8 The third lens 4.179 0.373 1.614 25.900 1.365 S9 -4.064 0.085 1.559 S10 The fourth lens 8.820 0.647 1.535 56.100 1.934 S11 11.669 0.524 2.133 S12 Fifth lens -3.694 0.400 1.535 56.100 2.327 S13 4.018 0.127 2.532 S14 Optical Filters infinity 0.110 1.518 64.166 2.622 S15 infinity 0.905 2.636 S16 Imaging surface infinity -0.015 2.824

[0179] The aspherical characteristics of the optical imaging system 800 according to the eighth example are listed in Table 16.

[0180] Table 16

[0181]

[0182]

[0183] The optical characteristic values ​​of the optical imaging systems according to the first example to the eighth example are listed in Table 17.

[0184] Table 17

[0185]

[0186] The conditional expression values ​​of the optical imaging systems according to the first example to the eighth example are listed in Table 18.

[0187] Table 18

[0188]

[0189]

[0190] As described above, an optical imaging system suitable for a high-performance compact camera can be realized.

[0191] Although specific examples 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 in this application should be understood in a descriptive sense only, and not for limiting purposes. The description of the features or aspects in each example should be understood to be applicable to similar features or aspects in other examples. If the described techniques are performed in a different order, and / or if the components in the described systems, architectures, devices, or circuits are combined in different ways and / or replaced or supplemented by other components or their equivalents, appropriate results can still be achieved. Therefore, the scope of the present disclosure is not limited by specific embodiments, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents should be understood to be included in the present disclosure.

Claims

1. Optical imaging system, include: Four or five lenses are arranged in sequence from the object side. Among the four or five lenses, a first lens disposed closest to the object side has a first reflection surface and a second reflection surface, the first reflection surface is configured to reflect light incident from the object side surface of the first lens, and the second reflection surface is configured to reflect the light reflected by the first reflection surface to the image side surface of the first lens, Among the four or five lenses, the last lens disposed closest to the image side has an inflection point formed on at least one of the object side surface and the image side surface, wherein at least one of the four or five lenses comprises an aspherical surface, wherein the first lens has positive refractive power, the second lens adjacent to the first lens has negative refractive power, and the last lens has negative refractive power, wherein the first lens has a concave image side surface, and the last lens is a biconcave lens, wherein the second lens has a concave object-side surface and a convex image-side surface in a paraxial region, wherein the third lens adjacent to the image side surface of the second lens has positive refractive power and a convex image side surface, and 0.28 < TTL / f < 0.32, Wherein, TTL is the distance from the object side surface of the first lens to the imaging surface, and f is the focal length of the optical imaging system.

2. The optical imaging system according to claim 1, in, 1.0 < f / f1 < 2.0, Wherein, f is the focal length of the optical imaging system, and f1 is the focal length of the first lens.

3. The optical imaging system according to claim 1, in, 4.30 < L1S1ER / L1S2ER < 5.80 Wherein, L1S1ER is the effective radius of the object-side surface of the first lens, and L1S2ER is the effective radius of the image-side surface of the first lens.

4. Optical imaging system, include: The first lens, the second lens, the third lens, the fourth lens and the fifth lens are arranged in order from the object side. wherein the first lens has positive refractive power and a concave image side surface, wherein the second lens has negative refractive power and has a concave object-side surface and a convex image-side surface in a paraxial region, The third lens has positive refractive power and a convex image side surface. wherein the fourth lens has a concave image side surface in the paraxial region, and the fifth lens has negative refractive power and is a biconcave lens, The first lens has a first reflecting surface and a second reflecting surface, the first reflecting surface is configured to reflect light incident from the object side surface of the first lens, and the second reflecting surface is configured to reflect the light reflected by the first reflecting surface to the image side surface of the first lens, wherein at least one of the first to fourth lenses comprises an aspherical surface, The optical imaging system comprises five lenses with refractive power in total, and 0.28 < TTL / f < 0.32, Wherein, TTL is the distance from the object side surface of the first lens to the imaging surface, and f is the focal length of the optical imaging system.

5. The optical imaging system according to claim 4, in, The fifth lens is disposed on the image side of the fourth lens.

6. The optical imaging system according to claim 4, in, An inflection point is formed on the object-side surface or the image-side surface of the fifth lens.

Images