Optical imaging system

Abstract

This invention provides an optical imaging system comprising: a lens unit including at least three lenses; an image sensor that moves along the optical axis and receives light that has passed through the lens unit; and a reflecting member disposed on the object side of the lens unit and having a reflective surface that alters the path of light. The optical imaging system satisfies 0 < (SAS / f) / OD < 0.15, where SAS is the moving distance of the image sensor along the optical axis, f is the total focal length of the lens unit, and OD is the object distance.

Description

[Technical Field]

[0001] The following description relates to an optical imaging system. Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0078142, filed with the Korean Intellectual Property Office on June 16, 2021, the entire disclosure of which is incorporated herein by reference for all purposes. [Previous Technology]

[0003] Cameras have been used in portable electronic devices such as smartphones, and miniaturization of cameras installed in portable electronic devices has become necessary due to the need for miniaturization of portable electronic devices.

[0004] In addition, telephoto cameras have been used in portable electronic devices to achieve a zoom effect when imaging objects using a narrow field of view.

[0005] However, when multiple lenses are arranged in the thickness direction of a portable electronic device as in a conventional camera, the thickness of the portable electronic device can increase with the increase in the number of lenses, making it difficult to reduce the size of the portable electronic device.

[0006] Specifically, because telephoto cameras have a relatively long focal length, it may be difficult to apply them to thin portable electronic devices.

[0007] Furthermore, in cameras with focus adjustment and optical image stabilization functions, the lens module, which typically contains multiple lenses, is movable. In this case, power consumption may increase due to the weight of the lens module. [Summary of the Invention]

[0008] This summary is provided to introduce, in a simplified form, the concept selection further described below in the embodiments. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to serve as an aid in determining the scope of the claimed subject matter.

[0009] In a general configuration, an optical imaging system includes: a lens unit comprising at least three lenses; an image sensor configured to move along an optical axis and receive light that has passed through the lens unit; and a reflective component disposed on the object side of the lens unit and having a reflective surface for changing the path of light, wherein 0 < (SAS / f) / OD < 0.15 [1 / meter], where SAS is the distance the image sensor moves along the optical axis, f is the total focal length of the lens unit, and OD is the object distance.

[0010] The lens unit may include a first lens, a second lens and a third lens arranged sequentially from the object side, and the optical imaging system may satisfy 0.6 mm < AFS_1.0 < 0.8 mm, where AFS_1.0 is the moving distance of the image sensor along the optical axis relative to the object distance of 1 meter.

[0011] The image sensor can be configured to move in a direction perpendicular to the optical axis, and the optical imaging system can satisfy 0.4 mm < OISC_1.0 < 0.5 mm, where OISC_1.0 is the movement distance of the image sensor in a direction perpendicular to the optical axis relative to a jitter of 1.0 degrees.

[0012] The first lens may have positive refractive power, the second lens may have negative refractive power, and the third lens may have positive refractive power.

[0013] Each of the first lens, the second lens and the third lens may include a protruding object-side surface and a recessed image-side surface.

[0014] The lens unit may include a first lens, a second lens, a third lens and a fourth lens arranged sequentially from the object side, and the optical imaging system may satisfy 0.15 mm < AFS_1.0 < 0.25 mm, where AFS_1.0 is the moving distance of the image sensor along the optical axis relative to the object distance of 1 meter.

[0015] The image sensor can be configured to move in a direction perpendicular to the optical axis, and the optical imaging system can satisfy 0.2 mm < OISC_1.0 < 0.3 mm, where OISC_1.0 is the movement distance of the image sensor in a direction perpendicular to the optical axis relative to a jitter of 1.0 degrees.

[0016] The image sensor can be configured to move in a direction perpendicular to the optical axis, and the optical imaging system can satisfy 0.15 mm < OISC_1.0 < 0.25 mm, where OISC_1.0 is the movement distance of the image sensor in a direction perpendicular to the optical axis relative to a jitter of 1.0 degrees.

[0017] The first lens may have positive refractive power, the second lens may have negative refractive power, the third lens may have positive refractive power, and the fourth lens may have positive refractive power.

[0018] The first lens may include a protruding object side surface and a protruding image side surface, and the fourth lens may include a protruding object side surface and a recessed image side surface.

[0019] The second lens may include a concave object side surface and a concave image side surface, and the third lens may include a convex object side surface and a concave image side surface.

[0020] The second lens may include a protruding object side surface and a recessed image side surface, and the third lens may include a protruding object side surface and a protruding image side surface.

[0021] The lens unit may include a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged sequentially from the object side, and the optical imaging system may satisfy 0.4 mm < AFS_1.0 < 0.6 mm, where AFS_1.0 is the moving distance of the image sensor relative to the object distance of 1 meter in the optical axis direction.

[0022] The image sensor can be configured to move in a direction perpendicular to the optical axis, and the optical imaging system can satisfy 0.3 mm < OISC_1.0 < 0.4 mm, where OISC_1.0 is the movement distance of the image sensor in a direction perpendicular to the optical axis relative to a jitter of 1.0 degrees.

[0023] The first lens may have positive refractive power, the second lens may have negative refractive power, the third lens may have positive refractive power, the fourth lens may have negative refractive power, and the fifth lens may have positive refractive power.

[0024] The first lens may include a protruding object-side surface and a protruding image-side surface, the second lens may include a recessed object-side surface and a recessed image-side surface, and each of the third, fourth and fifth lenses may include a protruding object-side surface and a recessed image-side surface.

[0025] The optical imaging system can satisfy 0.4<f1 / |f_rest|<1, where f1 is the focal length of the lens closest to the object side, and f_rest is the combined focal length of the lenses in the lens unit excluding the lens closest to the object side.

[0026] In another general embodiment, an optical imaging system includes: a lens unit comprising at least three lenses and no more than five lenses; and an image sensor disposed on the image side of the lens unit and configured to move along the optical axis and in a direction perpendicular to the optical axis, wherein 0 < (SAS / f) / OD < 0.15 [1 / meter], where SAS is the moving distance of the image sensor along the optical axis, f is the total focal length of the lens unit, and OD is the object distance, and wherein 0.15 mm < OISC_1.0 < 0.5 mm, where OISC_1.0 is the moving distance of the image sensor in a direction perpendicular to the optical axis relative to a jitter of 1.0 degrees.

[0027] The optical imaging system may include a reflective component mounted on the object side of the lens unit.

[0028] The optical imaging system can satisfy 0.8 < TTL / f << 1, where TTL is the optical axis distance from the object-side surface of the lens closest to the object-side of the lens unit to the imaging plane.

[0029] Other features and appearances will be apparent from the following embodiments, drawings and the scope of the claims.

Implementation Method

[0031] The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent to those skilled in the art. As will be apparent to those skilled in the art, the order of operations described herein is merely an example, and not limited to, those examples, except for those that must occur in a certain order, and is subject to change. Furthermore, for clarity and brevity, descriptions of functions and structures well known to those skilled in the art may be omitted.

[0032] The features described herein may be manifested in different forms and should not be construed as being limited to the instances described herein. In fact, instances described herein have been provided to make this disclosure thorough and complete, and these instances will fully convey the scope of this disclosure to those skilled in the art.

[0033] In this document, it should be noted that the term "may" is used with respect to an embodiment or instance, for example, with regard to what an embodiment or instance may contain or implement, meaning that there exists at least one embodiment or instance that contains or implements this feature, but all instances and examples are not limited thereto.

[0034] Throughout this specification, when an element such as a layer, region, or substrate is described as being "on" another element, "connected to" another element, or "coupled to" another element, the element may be directly "on" another element, "connected to" another element, or "coupled to" another element, or one or more other elements may be interposed therein. Conversely, when an element is described as being "directly above" another element, "directly connected to" another element, or "directly coupled to" another element, no other elements may be interposed therein.

[0035] As used herein, the term "and / or" includes any one of the associated listed items and any combination of two or more of them.

[0036] Although terms such as “first,” “second,” and “third” may be used herein to describe various parts, components, areas, layers, or sections, such parts, components, areas, layers, or sections are not limited to these terms. In fact, these terms are used only to distinguish one part, component, area, layer, or section from another part, component, area, layer, or section. Therefore, without departing from the teaching of the examples described herein, the first part, component, area, layer, or section referred to as the second part, component, area, layer, or section may also be referred to as the second part, component, area, layer, or section.

[0037] For ease of description, spatial relative terms such as “above,” “upper,” “below,” and “lower” may be used herein to describe the relationship between one element and another as shown in the figures. In addition to the orientations depicted in the figures, such spatial relative terms are intended to cover different orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as being “above” or “upper” relative to another element will then be located “below” or “lower” relative to said other element. Thus, depending on the spatial orientation of the device, the term “above” covers both upper and lower orientations. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and therefore the spatial relative terms used herein will be interpreted accordingly.

[0038] The terminology used herein is for the purpose of describing various instances only and is not intended to limit the scope of this disclosure. Unless the context clearly indicates otherwise, the articles "a / an" and "the" are intended to include plural forms. The terms "comprising," "including," and "having" specify the presence of the stated features, values, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, values, operations, components, elements, and / or combinations thereof.

[0039] Due to manufacturing techniques and / or limitations, 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 shape changes that occur during manufacturing.

[0040] As will be apparent upon understanding the disclosure of this application, the features of the instances described herein can be combined in various ways. Furthermore, although the instances described herein have various configurations, other configurations are also possible, as will be apparent upon understanding the disclosure of this application.

[0041] The drawings may not be drawn to scale, and for clarity, explanation and convenience, the relative size, scale and depiction of the elements in the drawings may be enlarged.

[0042] In the following, examples of the disclosure will be described with respect to the accompanying drawings.

[0043] In the lens diagram, the thickness, size and shape of the lens are magnified, and specifically, the shapes of spherical or aspherical surfaces shown in the lens diagram are merely examples and not limited thereto.

[0044] Optical imaging systems according to various embodiments may include lens units, and lens units may include multiple lenses arranged along the optical axis. The multiple lenses may be spaced apart from each other by a predetermined distance along the optical axis. The multiple lenses may include at least three lenses.

[0045] For example, an optical imaging system may contain three or more lenses.

[0046] Various examples have described optical imaging systems with three, four, or five lenses, but the examples are not limited thereto. For example, an optical imaging system may contain six or more lenses.

[0047] The foremost lens may refer to the lens closest to the object-side surface (or the reflecting component), and the last lens may refer to the lens closest to the image sensor.

[0048] Furthermore, in each lens, the first surface may refer to the surface adjacent to the object side (or the object-side surface), and the second surface may refer to the surface adjacent to the image side (or the image-side surface). Additionally, in various examples, the radius of curvature, thickness, and similar parameters of the lens are indicated in millimeters (mm), and the angles are indicated in degrees.

[0049] In the description of the shape of the lens, the paraxial region of the configuration indicating the surface with one surface being convex is convex, and the paraxial region of the configuration indicating the surface with one surface being concave is concave.

[0050] The paraxial region can refer to a narrow region adjacent to the optical axis.

[0051] The imaging plane may refer to a virtual plane on which the optical imaging system forms a focal point. Alternatively, the imaging surface may refer to a surface of an image sensor on which light is received.

[0052] The optical imaging system in various examples may contain at least three lenses.

[0053] For example, an optical imaging system may include a first lens, a second lens, and a third lens arranged sequentially from the object side. The first lens may be the foremost lens, and the third lens may be the last lens.

[0054] Alternatively, the optical imaging system may include a first lens, a second lens, a third lens, and a fourth lens arranged sequentially from the object side. The first lens may be the foremost lens, and the fourth lens may be the last lens.

[0055] Alternatively, the optical imaging system may include a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially from the object side. The first lens may be the foremost lens, and the fifth lens may be the last lens.

[0056] Optical imaging systems in various examples may further include components other than lenses.

[0057] For example, the optical imaging system may further include a reflective element having a reflective surface for changing the path of light. For example, the reflective element may be implemented as a mirror or a prism.

[0058] The reflecting element may be positioned closer to the object side than the plurality of lenses. For example, the reflecting element may be positioned in front of the first lens (closer to the object side than the first lens). Therefore, the lens positioned closest to the object side may be positioned closest to the reflecting element.

[0059] The optical imaging system may further include an image sensor for converting the incident image of an object into an electrical signal.

[0060] The optical imaging system may further include an infrared cut-off filter (hereinafter referred to as the filter) for blocking infrared light. The filter may be positioned between the lens (last lens) closest to the image sensor and the image sensor.

[0061] The integral lens contained in the optical imaging system in various examples may be formed of plastic material.

[0062] In various examples of optical imaging systems, the refractive index of the second lens may be greater than that of the first lens. Furthermore, the average refractive index of lenses other than the first lens may be configured to be greater than that of the first lens.

[0063] Optical imaging systems in various embodiments can be configured such that the image sensor is movable to adjust the focus of the image or correct image jitter. For example, the image sensor of the optical imaging system in various embodiments can be moved in the direction of the optical axis and / or in a direction perpendicular to the optical axis.

[0064] In other words, the image sensor can move along the optical axis to focus on the object.

[0065] Furthermore, when tremors occur during imaging due to user hand tremors or similar, the tremors can be corrected by applying a relative displacement corresponding to the tremors to the image sensor.

[0066] Although not shown in the figures, a drive unit may be provided to move the image sensor, and the drive unit may include a VCM actuator using magnets and coils.

[0067] The optical imaging systems in various examples may have the characteristics of telephoto lenses with relatively narrow field of view and long focal length.

[0068] Each of the plurality of lenses may have at least one aspherical surface.

[0069] In other words, at least one of the first and second surfaces of each lens may be an aspherical surface. The aspherical surface of each lens can be represented by Equation 1. [Equation 1]

[0070] In Equation 1, c is the curvature of the lens (the reciprocal of the radius of curvature), K is the conic constant, and Y is the distance from a point on the aspherical surface of the lens to the optical axis. Furthermore, constants A to J are aspherical coefficients. Z is the distance from a point on the aspherical surface of the lens to the vertex of the aspherical surface (SAG).

[0071] The optical imaging systems in various examples can satisfy the following condition expression 1: Condition expression 1: 0 < (SAS / f) / OD < 0.15 [1 / meter]

[0072] In addition, the optical imaging systems in various examples can satisfy at least one of the following conditional expressions: Conditional expression 2: 0 < L1S1 / f < 0.3 Conditional expression 3: -2 < (L1S1 + L1S2) / (L1S1 - L1S2) < 0 Conditional expression 4: 0 < L2S2 / f < 0.3 Conditional expression 5: 0.5 < (L2S1 + L2S2) / (L2S1 - L2S2) < 2 Conditional expression 6: 2 < f / f1 < 3.5 Conditional expression 7: -4.5 < f / f2 < -2 Conditional expression 8: 0.5 < BFL / TTL < 0.8 Conditional expression 9: 2.2 < TTL / (2*IMG HT) < 5 Conditional expression 10: 0.8 < TTL / f < 1 Conditional expression 11: 0.4 < f1 / |f_rest| < 1 Conditional expression 12: 1.6 < n_avg < 1.7

[0073] In the conditional expression, SAS is the moving distance of the image sensor in the optical axis direction, f is the total focal length of the optical imaging system, and OD is the object distance.

[0074] In the conditional expression, L1S1 is the radius of curvature of the object-side surface of the first lens, L1S2 is the radius of curvature of the image-side surface of the first lens, L2S1 is the radius of curvature of the object-side surface of the second lens, and L2S2 is the radius of curvature of the image-side surface of the second lens.

[0075] In the conditional expression, f1 is the focal length of the first lens, f2 is the focal length of the second lens, and f_rest is the combined focal length of the lenses other than the first lens.

[0076] In the conditional expression, BFL is the optical axis distance from the image-side surface of the last lens to the imaging plane, TTL is the optical axis distance from the object-side surface of the foremost lens to the imaging plane, and IMG HT is half the diagonal length of the imaging plane.

[0077] In the conditional expression, n_avg is the average refractive index of the lenses other than the first lens.

[0078] The optical imaging system according to the first example will be described with reference to Figures 1 and 2.

[0079] The optical imaging system in the first embodiment may include an optical system comprising a first lens 110, a second lens 120 and a third lens 130, and may further include a filter 160 and an image sensor IS.

[0080] Furthermore, the optical imaging system may further include a reflective element R, which is disposed in front of the first lens 110 and has a reflective surface for changing the path of light. In a first embodiment, the reflective element R may be implemented as a prism, but may also be implemented as a mirror.

[0081] The optical imaging system in the first embodiment can form a focal point on the imaging surface 170. The imaging surface 170 may refer to the surface on which the optical imaging system forms a focal point. For example, the imaging surface 170 may refer to a surface of an image sensor IS that receives light thereon.

[0082] The lens properties of each lens (lens radius of curvature, thickness or distance between lenses, refractive index, Abbe number, and focal length) are provided as shown in Table 1. [Table 1] Surface number Notes radius of curvature Thickness or distance Refractive index Abbe number focal length S1 Reflective components infinity 2.500 1.717 29.5 S2 infinity 2.500 1.717 29.5 S3 infinity 2.000 S4 First lens 4.978 2.308 1.535 56 9.449 S5 115.305 0.150 S6 Second lens 23.763 0.674 1.615 25.9 -7.558 S7 3.875 1.341 S8 Third lens 9.270 1.121 1.671 19.2 22.388 S9 22.569 16.469 S10 Filter infinity 0.300 1.516 64.1 S11 infinity 2.095 S12 Imaging plane infinity

[0083] The total focal length f of the optical imaging system in the first example can be 26 mm, the F number of the optical imaging system (hereinafter referred to as "Fno") can be 4.3, half the length of the diagonal of the imaging plane 170 can be 2.49 mm, and the combined focal length of the second lens 120 and the third lens 130 can be -12.143 mm.

[0084] In the first embodiment, the first lens 110 may have positive refractive power, the first surface of the first lens 110 may be convex, and the second surface of the first lens 110 may be concave.

[0085] The second lens 120 may have negative refractive power, the first surface of the second lens 120 may be convex, and the second surface of the second lens 120 may be concave.

[0086] The third lens 130 may have positive refractive power, the first surface of the third lens 130 may be convex, and the second surface of the third lens 130 may be concave.

[0087] The optical imaging system in the first embodiment can be configured such that the image sensor IS is movable for focus adjustment. For example, the image sensor IS of the optical imaging system in the first embodiment can be moved in the direction of the optical axis.

[0088] Table 2 lists the movement distance AFS of the image sensor IS in the optical axis direction based on the object distance OD in the optical imaging system of the first example. [Table 2] Object distance The distance the image sensor moves along the optical axis 2.0 meters 0.3431 mm 1.5 meters 0.4599 mm 1.0 meters 0.6969 mm 0.5 meters 1.438 mm

[0089] The optical imaging system in the first example can satisfy the following conditional expression: Conditional expression 13: 0.6 mm < AFS_1.0 < 0.8 mm

[0090] In the conditional expression, AFS_1.0 is the distance the image sensor IS moves relative to the object distance OD of 1.0 meters in the optical axis direction.

[0091] The optical imaging system in the first embodiment can be configured such that the image sensor IS is movable in order to perform optical image stabilization. For example, the image sensor IS of the optical imaging system in the first embodiment can be moved in a direction perpendicular to the optical axis.

[0092] Table 3 lists the distance the image sensor IS moves in the direction perpendicular to the optical axis, based on the jitter amount in the optical imaging system of the first example. The jitter amount can be measured by a jitter detection unit (e.g., a gyroscope sensor). [Table 3] jitter The distance the image sensor moves in the direction perpendicular to the optical axis 0.5 degrees 0.226 mm 1.0 degrees 0.453 mm 1.5 degrees 0.680 mm 2.0 degrees 0.907 mm

[0093] The optical imaging system in the first example can satisfy the following conditional expression: Conditional expression 14: 0.4 mm < OISC_1.0 < 0.5 mm

[0094] In the conditional expression, OISC_1.0 is the distance the image sensor IS moves relative to a jitter of 1.0 degrees in a direction perpendicular to the optical axis.

[0095] Since the optical imaging system in the first example can perform focus adjustment and optical image stabilization by moving the image sensor IS, power consumption may be reduced.

[0096] Each surface of the first lens 110 to the third lens 130 may have aspheric coefficients as provided in Table 4. For example, the object-side surface and image-side surface of the first lens 110 to the third lens 130 may be aspherical. [Table 4] S4 S5 S6 S7 S8 S9 Conic constant (K) 0.108586173 -99 44.28062425 0.325078127 -0.35515807 19.64907497 4th coefficient (A) -1.751E-04 -5.496E-03 -1.286E-02 -1.084E-02 -9.784E-04 -2.156E-04 6th coefficient (B) 1.202E-04 1.107E-02 1.377E-02 4.395E-03 1.784E-05 -1.174E-05 Coefficient 8 (C) -4.339E-05 -8.674E-03 -1.028E-02 -2.562E-03 8.828E-05 -7.900E-06 10th coefficient (D) 5.345E-07 3.930E-03 4.838E-03 1.336E-03 -8.287E-06 3.946E-05 12th coefficient (E) 3.222E-06 -1.100E-03 -1.421E-03 -4.407E-04 4.238E-06 -1.553E-05 Coefficient 14 (F) -9.608E-07 1.914E-04 2.599E-04 9.066E-05 3.061E-07 5.783E-06 16th coefficient (G) 1.293E-07 -2.005E-05 -2.867E-05 -1.157E-05 -7.951E-07 -1.820E-06 Coefficient 18 (H) -8.500E-09 1.153E-06 1.741E-06 8.345E-07 1.633E-07 2.877E-07 20th coefficient (J) 2.207E-10 -2.790E-08 -4.461E-08 -2.545E-08 -9.826E-09 -1.677E-08

[0097] In addition, the optical imaging system configured as described above may have the aberration properties shown in Figure 2.

[0098] The optical imaging system according to the second example will be described with reference to Figures 3 and 4.

[0099] The optical imaging system in the second example may include an optical system comprising a first lens 210, a second lens 220 and a third lens 230, and may further include a filter 260 and an image sensor IS.

[0100] Furthermore, the optical imaging system may further include a reflective element R, which is disposed in front of the first lens 210 and has a reflective surface for changing the path of light. In a second embodiment, the reflective element R may be implemented as a prism, but may also be implemented as a mirror.

[0101] In the second example, the optical imaging system can form a focal point on the imaging surface 270. The imaging surface 270 may refer to the surface on which the optical imaging system forms a focal point. For example, the imaging surface 270 may refer to a surface of an image sensor IS that receives light thereon.

[0102] The lens properties of each lens (lens radius of curvature, thickness or distance between lenses, refractive index, Abbe number, and focal length) are provided as shown in Table 5. [Table 5] Surface number Notes radius of curvature Thickness or distance Refractive index Abbe number focal length S1 Reflective components infinity 2.500 1.717 29.5 S2 infinity 2.500 1.717 29.5 S3 infinity 2.000 S4 First lens 5.055 2.550 1.583 59.4 9.517 S5 44.279 0.096 S6 Second lens 19.256 0.620 1.615 25.9 -7.330 S7 3.635 1.408 S8 Third lens 5.762 0.799 1.671 19.2 20.798 S9 9.182 16.088 S10 Filter infinity 0.300 1.516 64.1 S11 infinity 2.089 S12 Imaging plane infinity

[0103] In the second example, the total focal length f of the optical imaging system can be 26 mm, Fno can be 4.1, half the diagonal length of the imaging plane 270 can be 2.49 mm, and the combined focal length of the second lens 220 and the third lens 230 can be -11.902 mm.

[0104] In the second example, the first lens 210 may have positive refractive power, the first surface of the first lens 210 may be convex, and the second surface of the first lens 210 may be concave.

[0105] The second lens 220 may have negative refractive power, the first surface of the second lens 220 may be convex, and the second surface of the second lens 220 may be concave.

[0106] The third lens 230 may have positive refractive power, the first surface of the third lens 230 may be convex, and the second surface of the third lens 230 may be concave.

[0107] The optical imaging system in the second example can be configured such that the image sensor IS is movable for focus adjustment. For example, the image sensor IS of the optical imaging system in the second example can be moved in the direction of the optical axis.

[0108] Table 6 lists the movement distance AFS of the image sensor IS in the optical axis direction based on the object distance OD in the optical imaging system of the second example. [Table 6] Object distance The distance the image sensor moves along the optical axis 2.0 meters 0.3431 mm 1.5 meters 0.4599 mm 1.0 meters 0.6969 mm 0.5 meters 1.438 mm

[0109] The optical imaging system in the second example can satisfy the following conditional expression: Conditional expression 13: 0.6 mm < AFS_1.0 < 0.8 mm

[0110] In the conditional expression, AFS_1.0 is the distance the image sensor IS moves relative to the object distance OD of 1.0 meters in the optical axis direction.

[0111] The optical imaging system in the second example can be configured such that the image sensor IS is movable in order to perform optical image stabilization. For example, the image sensor IS of the optical imaging system in the second example can be moved in a direction perpendicular to the optical axis.

[0112] Table 7 lists the distance the image sensor IS moves in the direction perpendicular to the optical axis, based on the jitter amount in the optical imaging system of the second example. The jitter amount can be measured by a jitter detection unit (e.g., a gyroscope sensor). [Table 7] jitter The distance the image sensor moves in the direction perpendicular to the optical axis 0.5 degrees 0.226 mm 1.0 degrees 0.453 mm 1.5 degrees 0.680 mm 2.0 degrees 0.907 mm

[0113] The optical imaging system in the second example can satisfy the following condition expression: Condition expression 14: 0.4 mm < OISC_1.0 < 0.5 mm

[0114] In the conditional expression, OISC_1.0 is the distance the image sensor IS moves relative to a jitter of 1.0 degrees in a direction perpendicular to the optical axis.

[0115] Since the optical imaging system in the second example can perform focus adjustment and optical image stabilization by moving the image sensor IS, power consumption may be reduced.

[0116] Each surface of the first lens 210 to the third lens 230 may have aspheric coefficients as provided in Table 8. For example, the object-side surface and image-side surface of the first lens 210 to the third lens 230 may be aspherical. [Table 8] S4 S5 S6 S7 S8 S9 Conic constant (K) 0.092974225 -99 38.62148519 0.210473924 -0.67684378 8.914952795 4th coefficient (A) -1.992E-04 -5.690E-03 -1.439E-02 -1.244E-02 -7.820E-04 -1.043E-03 6th coefficient (B) 1.659E-04 1.543E-02 1.856E-02 5.013E-03 -2.748E-05 9.001E-05 Coefficient 8 (C) -1.095E-04 -1.478E-02 -1.674E-02 -3.713E-03 2.999E-05 -2.919E-04 10th coefficient (D) 3.505E-05 7.971E-03 9.267E-03 2.672E-03 8.982E-05 2.462E-04 12th coefficient (E) -6.606E-06 -2.601E-03 -3.133E-03 -1.199E-03 -5.785E-05 -1.125E-04 Coefficient 14 (F) 6.742E-07 5.199E-04 6.490E-04 3.305E-04 2.742E-05 4.540E-05 16th coefficient (G) -2.810E-08 -6.199E-05 -8.025E-05 -5.548E-05 -7.851E-06 -1.289E-05 Coefficient 18 (H) -3.753E-10 4.038E-06 5.429E-06 5.187E-06 1.098E-06 1.913E-06 20th coefficient (J) 4.625E-11 -1.104E-07 -1.544E-07 -2.058E-07 -5.807E-08 -1.101E-07

[0117] In addition, the optical imaging system configured as described above can have the aberration properties shown in Figure 4.

[0118] The optical imaging system according to the third example will be described with reference to Figures 5 and 6.

[0119] The optical imaging system in the third embodiment may include an optical system comprising a first lens 310, a second lens 320, a third lens 330 and a fourth lens 340, and may further include a filter 360 and an image sensor IS.

[0120] Furthermore, the optical imaging system may further include a reflective element R, which is disposed in front of the first lens 310 and has a reflective surface for changing the path of light. In a third embodiment, the reflective element R may be implemented as a prism, but may also be implemented as a mirror.

[0121] The optical imaging system in the third example can form a focal point on the imaging surface 370. The imaging surface 370 may refer to the surface on which the optical imaging system forms a focal point. For example, the imaging surface 370 may refer to a surface of an image sensor IS that receives light thereon.

[0122] The lens properties of each lens (lens radius of curvature, thickness or distance between lenses, refractive index, Abbe number, and focal length) are provided as shown in Table 9. [Table 9] Surface number Notes radius of curvature Thickness or distance Refractive index Abbe number focal length S1 Reflective components infinity 2.500 1.717 29.5 S2 infinity 2.500 1.717 29.5 S3 infinity 2.000 S4 First lens 3.400 1.557 1.535 56 5.097 S5 -11.836 0.089 S6 Second lens -25.187 0.827 1.615 25.9 -3.349 S7 2.294 0.497 S8 Third lens 6.06265 0.811 1.671 19.2 14.048 S9 15.73953 0.097 S10 Fourth lens 2.43661 0.630 1.615 25.9 19.674 S11 2.74271 7.586 S12 Filter infinity 0.300 1.516 64.1 S13 infinity 1.332 S14 Imaging plane infinity

[0123] In the third example, the total focal length f of the optical imaging system can be 14.5 mm, Fno can be 3.9, half the diagonal length of the imaging plane 370 can be 2.72 mm, and the combined focal length of the second lens 320 to the fourth lens 340 can be -5.672 mm.

[0124] In the third example, the first lens 310 may have positive refractive power, and the first surface and the second surface of the first lens 310 may be convex.

[0125] The second lens 320 may have negative refractive power, and the first surface and the second surface of the second lens 320 may be concave.

[0126] The third lens 330 may have positive refractive power, the first surface of the third lens 330 may be convex, and the second surface of the third lens 330 may be concave.

[0127] The fourth lens 340 may have positive refractive power, the first surface of the fourth lens 340 may be convex, and the second surface of the fourth lens 340 may be concave.

[0128] The optical imaging system in the third example can be configured such that the image sensor IS is movable for focus adjustment. For example, the image sensor IS of the optical imaging system in the third example can be moved in the direction of the optical axis.

[0129] Table 10 lists the movement distance AFS of the image sensor IS in the optical axis direction based on the object distance OD in the optical imaging system of the third example. [Table 10] Object distance The distance the image sensor moves along the optical axis 2.0 meters 0.1059 mm 1.5 meters 0.1415 mm 1.0 meters 0.2133 mm 0.5 meters 1.4328 mm

[0130] The optical imaging system in the third example can satisfy the following conditional expression: Conditional expression 15: 0.15 mm < AFS_1.0 < 0.25 mm

[0131] In the conditional expression, AFS_1.0 is the distance the image sensor IS moves relative to the object distance OD of 1.0 meters in the optical axis direction.

[0132] The optical imaging system in the third example can be configured such that the image sensor IS is movable in order to perform optical image stabilization. For example, the image sensor IS of the optical imaging system in the third example can be moved in a direction perpendicular to the optical axis.

[0133] Table 11 lists the distance the image sensor IS moves in the direction perpendicular to the optical axis, based on the jitter amount in the optical imaging system of the third example. The jitter amount can be measured by a jitter detection unit (e.g., a gyroscope sensor). [Table 11] jitter The distance the image sensor moves in the direction perpendicular to the optical axis 0.5 degrees 0.130 mm 1.0 degrees 0.261 mm 1.5 degrees 0.392 mm 2.0 degrees 0.523 mm

[0134] The optical imaging system in the third example satisfies the following conditional expression: Conditional expression 16: 0.2 < OISC_1.0 < 0.3

[0135] In the conditional expression, OISC_1.0 is the distance the image sensor IS moves relative to a jitter of 1.0 degrees in a direction perpendicular to the optical axis.

[0136] Since the optical imaging system in the third example can perform focus adjustment and optical image stabilization by moving the image sensor IS, power consumption may be reduced.

[0137] Each surface of the first lens 310 to the fourth lens 340 may have aspheric coefficients as provided in Table 12. For example, the object-side surface and image-side surface of the first lens 310 to the fourth lens 340 may be aspherical. [Table 12] S4 S5 S6 S7 Conic constant (K) -0.19462401 39.47526272 -53.7247539 0.228528713 4th coefficient (A) 5.636E-04 7.482E-03 -1.844E-02 -4.081E-02 6th coefficient (B) -6.645E-04 -2.307E-03 8.223E-03 1.549E-02 Coefficient 8 (C) 5.055E-04 8.451E-04 -8.890E-04 -3.313E-03 10th coefficient (D) -4.856E-04 1.913E-04 -1.097E-05 3.697E-04 12th coefficient (E) 2.142E-04 3.612E-06 5.894E-05 -4.566E-04 Coefficient 14 (F) -4.734E-05 -5.055E-05 -2.163E-05 3.394E-04 16th coefficient (G) 3.361E-06 5.926E-06 -6.124E-06 -1.334E-04 Coefficient 18 (H) 3.973E-07 -1.418E-06 -7.985E-07 2.498E-05 20th coefficient (J) -6.813E-08 6.644E-07 7.948E-07 1.914E-15 S8 S9 S10 S11 Conic constant (K) 12.22551644 80.81051093 -3.41152165 0.932324387 4th coefficient (A) 2.074E-02 1.003E-02 -1.797E-02 -3.891E-02 6th coefficient (B) -1.020E-02 -1.585E-04 1.689E-03 -8.794E-04 Coefficient 8 (C) 5.536E-03 -7.715E-04 -2.708E-04 2.598E-03 10th coefficient (D) -2.028E-03 2.679E-03 1.127E-03 -2.858E-03 12th coefficient (E) 2.629E-04 -9.033E-04 -1.892E-04 1.676E-03 Coefficient 14 (F) 0.000E+00 -2.320E-04 -1.074E-04 -3.796E-04 16th coefficient (G) 0.000E+00 1.495E-04 3.941E-05 1.087E-13 Coefficient 18 (H) 0.000E+00 9.833E-17 0.000E+00 -4.769E-19 20th coefficient (J) 0.000E+00 4.385E-17 0.000E+00 -1.184E-17

[0138] In addition, the optical imaging system configured as described above may have the aberration properties shown in Figure 6.

[0139] The optical imaging system according to the fourth example will be described with reference to Figures 7 and 8.

[0140] The optical imaging system in the fourth example may include an optical system comprising a first lens 410, a second lens 420, a third lens 430 and a fourth lens 440, and may further include a filter 460 and an image sensor IS.

[0141] Furthermore, the optical imaging system may further include a reflective element R, which is disposed in front of the first lens 410 and has a reflective surface for changing the path of light. In a fourth embodiment, the reflective element R may be implemented as a prism, but may also be implemented as a mirror.

[0142] The optical imaging system in the fourth example can form a focal point on the imaging surface 470. The imaging surface 470 may refer to the surface on which the optical imaging system forms a focal point. For example, the imaging surface 470 may refer to a surface of an image sensor IS that receives light thereon.

[0143] The lens properties of each lens (lens radius of curvature, thickness or distance between lenses, refractive index, Abbe number, and focal length) are provided as shown in Table 13. [Table 13] Surface number Notes radius of curvature Thickness or distance Refractive index Abbe number focal length S1 Reflective components infinity 2.500 1.717 29.5 S2 infinity 2.500 1.717 29.5 S3 infinity 2.000 S4 First lens 3.356 1.790 1.535 56 5.322 S5 -15.746 0.125 S6 Second lens 78.094 0.951 1.615 25.9 -4.114 S7 2.461 0.609 S8 Third lens 894.88000 0.951 1.671 19.2 25.344 S9 -17.53559 0.168 S10 Fourth lens 2.90836 0.742 1.615 25.9 29.008 S11 3.13005 6.262 S12 Filter infinity 0.336 1.516 64.1 S13 infinity 0.844 S14 Imaging plane infinity

[0144] In the fourth example, the total focal length f of the optical imaging system can be 13.2 mm, Fno can be 3.7, half the diagonal length of the imaging plane 470 can be 2.48 mm, and the combined focal length of the second lens 420 to the fourth lens 440 can be -6.109 mm.

[0145] In the fourth example, the first lens 410 may have positive refractive power, and the first surface and the second surface of the first lens 410 may be convex.

[0146] The second lens 420 may have negative refractive power, the first surface of the second lens 420 may be convex, and the second surface of the second lens 420 may be concave.

[0147] The third lens 430 may have positive refractive power, and the first surface and the second surface of the third lens 430 may be convex.

[0148] The fourth lens 440 may have positive refractive power, the first surface of the fourth lens 440 may be convex, and the second surface of the fourth lens 440 may be concave.

[0149] The optical imaging system in the fourth example can be configured such that the image sensor IS is movable for focus adjustment. For example, the image sensor IS of the optical imaging system in the fourth example can be moved in the direction of the optical axis.

[0150] Table 14 lists the movement distance AFS of the image sensor IS in the optical axis direction based on the object distance OD in the optical imaging system of the fourth example. [Table 14] Object distance The distance the image sensor moves along the optical axis 2.0 meters 0.0876 mm 1.5 meters 0.1171 mm 1.0 meters 0.1763 mm 0.5 meters 0.3572 mm

[0151] The optical imaging system in the fourth example can satisfy the following conditional expression: Conditional expression 15: 0.15 mm < AFS_1.0 < 0.25 mm

[0152] In the conditional expression, AFS_1.0 is the distance the image sensor IS moves relative to the object distance OD of 1.0 meters in the optical axis direction.

[0153] The optical imaging system in the fourth example can be configured such that the image sensor IS is movable for optical image stabilization. For example, the image sensor IS of the optical imaging system in the fourth example can be moved in a direction perpendicular to the optical axis.

[0154] Table 15 lists the distance the image sensor IS moves in the direction perpendicular to the optical axis, based on the jitter amount in the optical imaging system of the fourth example. The jitter amount can be measured by a jitter detection unit (e.g., a gyroscope sensor). [Table 15] jitter The distance the image sensor moves in the direction perpendicular to the optical axis 0.5 degrees 0.113 mm 1.0 degrees 0.226 mm 1.5 degrees 0.340 mm 2.0 degrees 0.453 mm

[0155] The optical imaging system in the fourth example can satisfy the following conditional expression: Conditional expression 17: 0.15 mm < OISC_1.0 < 0.25 mm

[0156] In the conditional expression, OISC_1.0 is the distance the image sensor IS moves relative to a jitter of 1.0 degrees in a direction perpendicular to the optical axis.

[0157] Since the optical imaging system in the fourth example can perform focus adjustment and optical image stabilization by moving the image sensor IS, power consumption may be reduced.

[0158] Each surface of the first lens 410 to the fourth lens 440 may have aspheric coefficients as provided in Table 16. For example, the object-side surface and image-side surface of the first lens 410 to the fourth lens 440 may be aspherical. [Table 16] S4 S5 S6 S7 Conic constant (K) -0.25205408 32.33789095 99 0.431592462 4th coefficient (A) -3.804E-04 -3.110E-03 -1.254E-02 -1.936E-02 6th coefficient (B) 7.648E-04 8.608E-03 1.314E-02 1.665E-02 Coefficient 8 (C) -1.298E-03 -6.190E-03 -6.053E-03 -8.434E-03 10th coefficient (D) 1.130E-03 1.973E-03 -6.441E-04 4.942E-03 12th coefficient (E) -6.248E-04 -2.323E-04 2.424E-03 1.717E-03 Coefficient 14 (F) 2.135E-04 0.000E+00 -1.300E-03 -1.522E-03 16th coefficient (G) -4.505E-05 0.000E+00 3.343E-04 -9.735E-04 Coefficient 18 (H) 5.514E-06 0.000E+00 -4.310E-05 4.406E-04 20th coefficient (J) -3.032E-07 0.000E+00 2.095E-06 0.000E+00 S8 S9 S10 S11 Conic constant (K) 99 40.92235276 0.287993248 1.622687571 4th coefficient (A) 4.265E-03 2.070E-02 1.463E-02 -4.169E-03 6th coefficient (B) 3.253E-03 -2.065E-02 -2.192E-02 -5.907E-04 Coefficient 8 (C) 2.853E-03 1.841E-02 1.653E-02 -4.705E-03 10th coefficient (D) 2.408E-03 -4.592E-03 -7.013E-03 3.651E-03 12th coefficient (E) -2.308E-03 -2.528E-03 1.020E-03 -1.059E-03 Coefficient 14 (F) 0.000E+00 1.045E-03 0.000E+00 0.000E+00 16th coefficient (G) 0.000E+00 -6.991E-05 0.000E+00 0.000E+00 Coefficient 18 (H) 0.000E+00 0.000E+00 0.000E+00 0.000E+00 20th coefficient (J) 0.000E+00 0.000E+00 0.000E+00 0.000E+00

[0159] In addition, the optical imaging system configured as described above may have the aberration properties shown in Figure 8.

[0160] The optical imaging system according to the fifth example will be described with reference to Figures 9 and 10.

[0161] The optical imaging system in the fifth example may include an optical system comprising a first lens 510, a second lens 520, a third lens 530, a fourth lens 540 and a fifth lens 550, and may further include a filter 560 and an image sensor IS.

[0162] Furthermore, the optical imaging system may further include a reflective element R, which is disposed in front of the first lens 510 and has a reflective surface for changing the path of light. In a fifth embodiment, the reflective element R may be implemented as a prism, but may also be implemented as a mirror.

[0163] The optical imaging system in the fifth example can form a focal point on the imaging surface 570. The imaging surface 570 may refer to the surface on which the optical imaging system forms a focal point. For example, the imaging surface 570 may refer to a surface of an image sensor IS that receives light thereon.

[0164] The lens properties of each lens (lens radius of curvature, thickness or distance between lenses, refractive index, Abbe number, and focal length) are provided as shown in Table 17. [Table 17] Surface number Notes radius of curvature Thickness or distance Refractive index Abbe number focal length S1 Reflective components infinity 2.500 1.717 29.5 S2 infinity 2.500 1.717 29.5 S3 infinity 2.000 S4 First lens 5.189 2.200 1.535 56 8.214 S5 -24.946 0.248 S6 Second lens -333.325 1.000 1.615 25.9 -6.523 S7 4.103 1.506 S8 Third lens 5.07583 1.000 1.671 19.2 13.320 S9 10.64859 0.162 S10 Fourth lens 7.74817 0.867 1.615 25.9 -13.630 S11 3.87074 1.563 S12 Fifth lens 6.69216 1.000 1.535 56 22.345 S13 14.02434 7.981 S14 Filter infinity 0.300 1.516 64.1 S15 infinity 3.454 S16 Imaging plane infinity

[0165] In the fifth example, the total focal length f of the optical imaging system can be 22 mm, Fno can be 3.8, half the diagonal length of the imaging plane 570 can be 4.2 mm, and the combined focal length of the second lens 520 to the fifth lens 550 can be -9.85 mm.

[0166] In the fifth example, the first lens 510 may have positive refractive power, and the first surface and the second surface of the first lens 510 may be convex.

[0167] The second lens 520 may have negative refractive power, and the first surface and the second surface of the second lens 520 may be concave.

[0168] The third lens 530 may have positive refractive power, the first surface of the third lens 530 may be convex, and the second surface of the third lens 530 may be concave.

[0169] The fourth lens 540 may have negative refractive power, the first surface of the fourth lens 540 may be convex, and the second surface of the fourth lens 540 may be concave.

[0170] The fifth lens 550 may have positive refractive power, the first surface of the fifth lens 550 may be convex, and the second surface of the fifth lens 550 may be concave.

[0171] The optical imaging system in the fifth example can be configured such that the image sensor IS is movable for focus adjustment. For example, the image sensor IS of the optical imaging system in the fifth example can be moved in the direction of the optical axis.

[0172] Table 18 lists the movement distance AFS of the image sensor IS in the optical axis direction based on the object distance OD in the optical imaging system of the fifth example. [Table 18] Object distance The distance the image sensor moves along the optical axis 2.0 meters 0.2029 mm 1.5 meters 0.3456 mm 1.0 meters 0.5126 mm 0.5 meters 1.0283 mm

[0173] The optical imaging system in the fifth example can satisfy the following conditional expression: Conditional expression 18: 0.4 mm < AFS_1.0 < 0.6 mm

[0174] In the conditional expression, AFS_1.0 is the distance the image sensor IS moves relative to the object distance OD of 1.0 meters in the optical axis direction.

[0175] The optical imaging system in the fifth example can be configured such that the image sensor IS is movable for optical image stabilization. For example, the image sensor IS of the optical imaging system in the fifth example can be moved in a direction perpendicular to the optical axis.

[0176] Table 19 lists the distance the image sensor IS moves in the direction perpendicular to the optical axis, based on the jitter amount in the optical imaging system of the fifth example. The jitter amount can be measured by a jitter detection unit (e.g., a gyroscope sensor). [Table 19] jitter The distance the image sensor moves in the direction perpendicular to the optical axis 0.5 degrees 0.191 mm 1.0 degrees 0.384 mm 1.5 degrees 0.576 mm 2.0 degrees 0.768 mm

[0177] The optical imaging system in the fifth example can satisfy the following conditional expression: Conditional expression 19: 0.3 mm < OISC_1.0 < 0.4 mm

[0178] In the conditional expression, OISC_1.0 is the distance the image sensor IS moves relative to a jitter of 1.0 degrees in a direction perpendicular to the optical axis.

[0179] Since the optical imaging system in the fifth example can perform focus adjustment and optical image stabilization by moving the image sensor IS, power consumption may be reduced.

[0180] Each surface of the first lens 510 to the fifth lens 550 may have aspheric coefficients as provided in Table 20. For example, the object-side surface and image-side surface of the first lens 510 to the fifth lens 550 may be aspherical. [Table 20] S4 S5 S6 S7 S8 Conical constant -0.63588104 -16.6933114 -99 0.042706966 0.765523528 4th coefficient 3.896E-04 1.258E-03 -1.045E-03 -3.775E-03 -1.852E-03 6th coefficient 1.963E-05 -6.687E-04 -8.082E-04 -4.386E-04 9.111E-04 8th coefficient -7.647E-06 3.543E-04 5.863E-04 2.777E-04 -9.617E-04 10th coefficient (D) 3.335E-06 -1.063E-04 -1.917E-04 -4.573E-05 5.469E-04 12th coefficient (E) -7.910E-07 2.001E-05 3.873E-05 -7.721E-06 -1.667E-04 Coefficient 14 (F) 1.108E-07 -2.377E-06 -4.952E-06 4.833E-06 2.620E-05 16th coefficient (G) -9.087E-09 1.714E-07 3.866E-07 -8.920E-07 -1.665E-06 Coefficient 18 (H) 3.973E-10 -6.826E-09 -1.675E-08 7.581E-08 -3.191E-08 20th coefficient (J) -7.152E-12 1.149E-10 3.080E-10 -2.513E-09 6.183E-09 S9 S10 S11 S12 S13 Conical constant 4.170484928 -2.39760089 0.082090575 5.359714379 24.17237688 4th coefficient -4.327E-03 -5.626E-03 -5.280E-03 -6.300E-03 -3.964E-03 6th coefficient 7.426E-03 7.960E-03 1.669E-03 -4.794E-04 -2.560E-04 8th coefficient -9.056E-03 -1.068E-02 -3.363E-03 2.425E-04 2.881E-05 10th coefficient (D) 6.129E-03 7.556E-03 3.004E-03 -3.599E-04 -1.276E-04 12th coefficient (E) -2.378E-03 -3.046E-03 -1.451E-03 2.958E-04 1.428E-04 Coefficient 14 (F) 5.377E-04 7.207E-04 4.148E-04 -1.275E-04 -6.832E-05 16th coefficient (G) -6.904E-05 -9.805E-05 -6.956E-05 3.020E-05 1.695E-05 Coefficient 18 (H) 4.557E-06 6.992E-06 6.290E-06 -3.744E-06 -2.145E-06 20th coefficient (J) -1.149E-07 -1.977E-07 -2.357E-07 1.899E-07 1.096E-07

[0181] In addition, the optical imaging system configured as described above may have the aberration properties shown in Figure 10.

[0182] According to the foregoing example, the optical imaging system can be mounted on a thin portable electronic device and can be driven with low power.

[0183] Although this disclosure contains specific examples, it will be apparent to those skilled in the art 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 considered only in a descriptive sense and not for limiting purposes. The description of features or manner in each example should be regarded as applicable to similar features or manner in other examples. Suitable results may be achieved if the described techniques are performed in a different order, and / or if the components in the described system, architecture, device, or circuit are combined in a different manner, and / or replaced or supplemented by other components or their equivalents. Therefore, the scope of this disclosure is not defined by the implementation method but by the claims and their equivalents, and all changes falling within the scope of the claims and their equivalents should be interpreted as being included in this disclosure. [Simplified Explanation of the Diagram]

[0030] Figure 1 is a diagram illustrating an optical imaging system according to a first example. Figure 2 is an aberration curve of the optical imaging system shown in Figure 1. Figure 3 is a diagram illustrating an optical imaging system according to a second example. Figure 4 is an aberration curve of the optical imaging system shown in Figure 3. Figure 5 is a diagram illustrating an optical imaging system according to a third example. Figure 6 is an aberration curve of the optical imaging system shown in Figure 5. Figure 7 is a diagram illustrating an optical imaging system according to a fourth example. Figure 8 is an aberration curve of the optical imaging system shown in Figure 7. Figure 9 is a diagram illustrating an optical imaging system according to a fifth example. Figure 10 is an aberration curve of the optical imaging system shown in Figure 9. Throughout the figures and detailed description, the same reference numerals refer to the same elements. The figures may not be drawn to scale, and for clarity, illustration, and convenience, the relative size, scale, and depiction of the elements in the figures may be enlarged.

Claims

1. An optical imaging system, comprising: The first lens has positive refractive power; The second lens has negative refractive power; The third lens has positive refractive power, a protruding object-side surface and a concave image-side surface; The fourth lens has negative refractive power, a convex object-side surface, and a concave image-side surface; The system includes a fifth lens, which has refractive power, a convex object-side surface, and a concave image-side surface; wherein the first to the fifth lenses are 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 image sensor in an increasing numerical order; wherein the optical imaging system has a total of five lenses, and 2.2 < TTL / (2*IMG HT) < 5, where TTL is the optical axis distance from the object-side surface of the first lens to the imaging plane, and IMG HT is half the diagonal length of the imaging plane; wherein the second lens has a concave object-side surface and a concave image-side surface.

2. The optical imaging system as claimed in claim 1, wherein 2 < f / f1 < 3.5, where f is the total focal length of the optical imaging system and f1 is the focal length of the first lens.

3. The optical imaging system as claimed in claim 1, wherein -4.5 < f / f2 < -2, where f is the total focal length of the optical imaging system and f2 is the focal length of the second lens.

4. The optical imaging system as claimed in claim 1, wherein 0.4 < f1 / |f_rest| < 1, where f1 is the focal length of the first lens and f_rest is the combined focal length of the second lens, the third lens, the fourth lens and the fifth lens.

5. The optical imaging system as claimed in claim 1, wherein 0 < L1S1 / f < 0.3, where L1S1 is the radius of curvature of the object-side surface of the first lens, and f is the total focal length of the optical imaging system.

6. The optical imaging system as claimed in claim 1, wherein -2 < (L1S1 + L1S2) / (L1S1 - L1S2) < 0, wherein L1S1 is the radius of curvature of the object-side surface of the first lens, and wherein L1S2 is the radius of curvature of the image-side surface of the first lens.

7. The optical imaging system as claimed in claim 1, wherein 0 < L2S2 / f < 0.3, where L2S2 is the radius of curvature of the image-side surface of the second lens, and f is the total focal length of the optical imaging system.

8. The optical imaging system of claim 1, wherein 0.5 < (L2S1 + L2S2) / (L2S1 - L2S2) < 2, wherein L2S1 is the radius of curvature of the object-side surface of the second lens, and wherein L2S2 is the radius of curvature of the image-side surface of the second lens.

9. The optical imaging system as claimed in claim 1, wherein 0.5 < BFL / TTL < 0.8, where BFL is the optical axis distance from the image-side surface of the fifth lens to the imaging plane.

10. The optical imaging system as claimed in claim 1, wherein 0.8 < TTL / f < 1, where f is the total focal length of the optical imaging system.

11. The optical imaging system as claimed in claim 1, wherein 1.6 < n_avg < 1.7, and n_avg is the average refractive index of the second lens, the third lens, the fourth lens, and the fifth lens.

12. The optical imaging system of claim 1, wherein the refractive index of the second lens is greater than that of the first lens.

13. The optical imaging system of claim 1, wherein the average refractive index of the lenses other than the first lens is greater than the refractive index of the first lens.

14. The optical imaging system as claimed in claim 1, further comprising: A reflective element is positioned in front of the first lens and includes a reflective surface configured to alter the path of light.

15. The optical imaging system of claim 1, wherein the first lens has a protruding object-side surface and a protruding image-side surface.

Images