Optical imaging system

Abstract

An optical imaging system includes, in order from an object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, wherein TTL / (2*IMG_HT)≤0.6 is satisfied, where TTL is a distance on an optical axis from an object side surface of the first lens to an imaging surface of an image sensor, and IMG_HT is half of a diagonal length of the imaging surface of the image sensor.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0067933, filed on June 4, 2020, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. TECHNICAL FIELD

[0003] The present disclosure relates to an optical imaging system. BACKGROUND

[0004] A portable terminal device can be designed to include a camera having an optical imaging system provided with a plurality of lenses to perform a video call and image an object.

[0005] As functions of the camera can be required to be increased in the portable terminal device, there is an increasing demand for a camera having a high resolution for the portable terminal device.

[0006] As the portable terminal device can be designed to have a reduced size, the camera for the portable terminal device can be required to have a reduced size.

[0007] Therefore, there can be a need to develop an optical imaging system having a reduced size and a high resolution.

[0008] 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 regard to the present disclosure. SUMMARY

[0009] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the DETAILED DESCRIPTION. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter.

[0010] In one general aspect, an optical imaging system includes, in order from an object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, wherein TTL / (2xIMG_HT)≤0.6 is satisfied, where TTL is a distance on an optical axis from an object side surface of the first lens to an imaging surface of an image sensor, and IMG_HT is half of a diagonal length of the imaging surface of the image sensor.

[0011] A conditional expression (v2+v3+v4+v5) / v1<2 can be satisfied, where v1 is an Abbe number of the first lens, v2 is an Abbe number of the second lens, v3 is an Abbe number of the third lens, v4 is an Abbe number of the fourth lens, and v5 is an Abbe number of the fifth lens.

[0012] A conditional expression 0

[0013] A conditional expression -4

[0014] A conditional expression f3 / f>3 can be satisfied, where f3 is a focal length of the third lens.

[0015] A conditional expression |f4 / f|>3 can be satisfied, where f4 is a focal length of the fourth lens.

[0016] A conditional expression |f5 / f|>5 can be satisfied, where f5 is a focal length of the fifth lens.

[0017] A conditional expression 0

[0018] A conditional expression -2

[0019] A conditional expression TTL / f<1.2 can be satisfied, and a conditional expression BFL / f<0.3 can be satisfied, where BFL is a distance on an optical axis from an image side surface of the seventh lens to an imaging surface of the image sensor.

[0020] A conditional expression |f1 / f2|<1 can be satisfied.

[0021] A conditional expression -2

[0022] A conditional expression D1 / f<0.1 can be satisfied, where D1 is a distance on an optical axis from an image side surface of the first lens to an object side surface of the second lens.

[0023] A conditional expression 84°<FOV<92° can be satisfied, where FOV is a field of view of the optical imaging system.

[0024] A conditional expression Fno<2.2 can be satisfied, where Fno is an F number of the optical imaging system.

[0025] A conditional expression 1

[0026] The first lens can have a positive refractive power, the second lens can have a negative refractive power, the third lens can have a positive refractive power, the fourth lens can have a negative refractive power, the sixth lens can have a positive refractive power, and the seventh lens can have a negative refractive power.

[0027] The conditional expression 25 < v1-v2 < 45 can be satisfied.

[0028] The conditional expression v1-v3 < 35 can be satisfied.

[0029] The conditional expression 15 < v1-v5 < 25 can be satisfied.

[0030] Other features and aspects will be apparent from the following specific description, the drawings, and the appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a diagram illustrating a first example of an optical imaging system.

[0032] Figure 2 is a diagram illustrating a second example of an optical imaging system. Figure 1 is a diagram illustrating aberration characteristics of the optical imaging system illustrated.

[0033] Figure 3 is a diagram illustrating a third example of an optical imaging system.

[0034] Figure 4 is a diagram illustrating a fourth example of an optical imaging system. Figure 3 is a diagram illustrating aberration characteristics of the optical imaging system illustrated.

[0035] Figure 5 is a diagram illustrating a fifth example of an optical imaging system.

[0036] Figure 6 is a diagram illustrating a sixth example of an optical imaging system. Figure 5 is a diagram illustrating aberration characteristics of the optical imaging system illustrated.

[0037] Figure 7 is a diagram illustrating a seventh example of an optical imaging system.

[0038] Figure 8 is a diagram illustrating an eighth example of an optical imaging system. Figure 7 is a diagram illustrating aberration characteristics of the optical imaging system illustrated.

[0039] Figure 9 is a diagram illustrating a ninth example of an optical imaging system.

[0040] Figure 10 is a diagram illustrating an tenth example of an optical imaging system. Figure 9 is a diagram illustrating aberration characteristics of the optical imaging system illustrated.

[0041] Throughout the accompanying drawings and detailed embodiments, the same reference numerals denote the same elements. The drawings may not be drawn to scale, and for clarity, illustration, and convenience, the relative dimensions, scale, and depiction of elements in the drawings may be exaggerated. Detailed Implementation

[0042] In the following description, embodiments 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.

[0043] The following detailed embodiments are provided to aid the reader in fully understanding the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding this disclosure. For example, the sequences of operations described herein are merely examples and are not limited to those set forth herein; rather, changes may be made, except for operations that must occur in a certain order, as will become apparent upon understanding this disclosure. Furthermore, descriptions of features known in the art may be omitted for clarity and conciseness.

[0044] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are merely illustrative of some of the many possible ways to implement the methods, apparatus, and / or systems described herein, as will be apparent upon understanding this disclosure.

[0045] Throughout this specification, when an element such as a layer, region, or substrate is described as being “on,” “connected to,” or “attached to” another element, it may be directly “on,” “connected to,” or “attached to” another element, or one or more other elements may be present between them. Conversely, when an element is described as being “directly” “on,” “directly connected to,” or “directly attached to” another element, no other elements may be present between them. As used herein, a “part” of an element may include the entire element or less than the entire element.

[0046] As used herein, the term “and / or” includes any one of the listed items and any combination of any two or more related listed items; similarly, “…at least one” includes any one of the listed items and any combination of any two or more related listed items.

[0047] Although terminology can be used in this disclosure, such as "first," "second," and "third," the examples described herein are not limited to these terms and are used for the purpose of description only. Rather, these terms are only used to differentiate one component, assembly, region, layer, or portion from another component, assembly, region, layer, or portion. Thus, a first component, assembly, region, layer, or portion referred to in the examples described herein can also be termed a second component, assembly, region, layer, or portion, without departing from the teachings of the examples.

[0048] Spatially relative terms, such as "above," "upper," "below," "lower," and the like, can be used herein for ease of description to describe one element's or portion's relationship to another element(s) or portion(s) as illustrated in the figures. Such spatially relative terms can be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "up" other elements or portions would then be oriented "below" or "down" the other element(s), respectively. Thus, the term "above" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative terms used herein interpreted accordingly. The words "comprise," "comprising," "include," "including," and "has" or "have" (and its inflectional forms) such as "comprises" and "comprising," "includes" and "including" and "has" and "having" and "have" and "having" are used herein not to limit the entity, component, or act they modify to a certain number of entities, components, or acts. Rather, such words typically encompass the entities, components, or acts that the modification thereto excludes, more or less, as well as those the modification thereto expressly includes.

[0049] The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the present disclosure. The singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," "including," and the like in the description are specifically intended to be open-ended. Such terms are, therefore, to be interpreted to mean "including but not limited to." The description herein of examples of the disclosure encompasses that which falls within the scope of and equivalents thereof. The description herein of examples of the disclosure also includes examples of the features, structures, acts, means, components, and / or elements described herein in combination with each other, as well as examples involving such features, structures, acts, means, components, and / or elements individually.

[0050] Features of the examples described herein can be combined in a variety of ways as will be apparent after review of the disclosure. Additionally, although examples described herein have a variety of configurations, other configurations are possible in accordance with the disclosure.

[0051] The shapes shown in the drawings can vary due to manufacturing techniques and / or tolerances. Thus, the examples described herein are not limited to the specific shapes shown in the drawings, but include variations in shapes that occur during manufacturing.

[0052] In the following lens configuration diagrams, the thickness, size, and shape of the lenses can be shown in a slightly exaggerated manner for the purpose of illustration, for example, the shape of the spherical or aspherical surface of the lenses presented in the lens configuration diagrams is shown only as an example, and the shape is not limited thereto.

[0053] In this document, it should be noted that the use of the phrase "may" in relation to examples, for example, in relation to examples that can include or implement something, means that there is at least one example where the feature is included or implemented, and all examples are not limited thereto.

[0054] The first lens refers to the lens closest to the object side, and the seventh lens refers to the lens closest to the image sensor.

[0055] In addition, the first surface (or object side surface) refers to the surface closest to the object side, and the second surface (or image side surface) refers to the surface closest to the image side. In addition, the radius of curvature, thickness, distance, focal length, etc. of the lens are expressed in millimeters (mm), and the field of view (FOV) is expressed in degrees.

[0056] In the description of the lens shape, the configuration in which one of the surfaces is convex indicates that the paraxial region of the surface is convex, the configuration in which one of the surfaces is concave indicates that the paraxial region of the surface is concave, and the configuration in which one of the surfaces is flat indicates that the paraxial region of the surface is flat. Therefore, even when one surface of the lens is described as convex, the edge of the lens can be concave. Similarly, even when one surface of the lens is described as concave, the edge of the lens can be convex. Also, even when one surface of the lens is described as flat, the edge of the lens can be convex or concave.

[0057] The paraxial region refers to a narrow region close to the optical axis and including the optical axis.

[0058] One aspect of the present disclosure provides an optical imaging system that can achieve high resolution and can have a reduced size.

[0059] The optical imaging system in the exemplary embodiment can include seven lenses.

[0060] For example, the optical imaging system in the exemplary embodiment can include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens disposed in order from the object side. The first lens to the seventh lens can be spaced apart from each other by a predetermined distance along the optical axis.

[0061] However, the optical imaging system in the exemplary embodiment not only includes seven lenses, for example, the optical imaging system can also include other elements.

[0062] For example, the optical imaging system can further include an image sensor for converting an incident image of an object into an electrical signal.

[0063] Further, the optical imaging system can further include an infrared filter (hereinafter, referred to as a filter) for blocking infrared rays. The filter can be disposed between the seventh lens and the image sensor.

[0064] Further, the optical imaging system can further include a diaphragm for adjusting an amount of light.

[0065] In an exemplary embodiment, the first to seventh lenses included in the optical imaging system can be formed of a plastic material.

[0066] Further, at least one of the first to seventh lenses can have an aspherical surface. Further, each of the first to seventh lenses can have at least one aspherical surface.

[0067] In other words, at least one of the first and second surfaces of each of the first to seventh lenses can be aspherical. The aspherical surface of the first to seventh lenses can be expressed by Equation 1.

[0068] [Equation 1]

[0069]

[0070] In Equation 1, "c" is a curvature of a lens (an inverse of a radius of curvature), "k" is a conic constant, "Y" is a distance from a certain point on an aspherical surface of a lens to an optical axis. "A to P" are aspherical constants, and "Z" is a distance from a certain point on an aspherical surface to a vertex of the aspherical surface on the optical axis.

[0071] The optical imaging system including the first to seventh lenses can have positive, negative, positive, negative, positive, positive, and negative refractive powers, respectively, or can have positive, negative, positive, negative, negative, positive, and negative refractive powers, respectively.

[0072] The optical imaging system in an exemplary embodiment can satisfy at least one of the following conditional expressions:

[0073] [Conditional Expression 1] 0 < f1 / f < 1.8

[0074] [Conditional Expression 2] 25 < v1-v2 < 45

[0075] [Conditional Expression 3] v1-v3 < 35

[0076] [Conditional Expression 4] 15 < v1-v5 < 25

[0077] [Condition Expression 5] (v2 + v3 + v4 + v5) / vl < 2

[0078] [Condition Expression 6] -4 < f2 / f < -1

[0079] [Condition Expression 7] f3 / f > 3

[0080] [Condition Expression 8] |f4 / f| > 3

[0081] [Condition Expression 9] |f5 / f| > 5

[0082] [Condition Expression 10] 0 < f6 / f < 2

[0083] [Condition Expression 11] -2 < f7 / f < 0

[0084] [Condition Expression 12] TTL / f < 1.2

[0085] [Condition Expression 13] |f1 / f2| < 1

[0086] [Condition Expression 14] -2 < f2 / f3 < 0

[0087] [Condition Expression 15] BFL / f < 0.3

[0088] [Condition Expression 16] D1 / f < 0.1

[0089] [Condition Expression 17] 84° < FOV < 92°

[0090] [Condition Expression 18] Fno < 2.2

[0091] [Condition Expression 19] TTL / (2 x IMG HT) < 0.6

[0092] [Condition Expression 20] 1 < f12 / f < 2

[0093] In the condition expressions, f is a total focal length of the optical imaging system, f1 is a focal length of the first lens, f2 is a focal length of the second lens, f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, f5 is a focal length of the fifth lens, f6 is a focal length of the sixth lens, f7 is a focal length of the seventh lens, and f12 is a combined focal length of the first and second lenses.

[0094] vl is an Abbe number of the first lens, v2 is an Abbe number of the second lens, v3 is an Abbe number of the third lens, and v5 is an Abbe number of the fifth lens.

[0095] TTL is a distance on an optical axis from an object side surface of the first lens to an imaging surface of the image sensor, BFL is a distance on the optical axis from an image side surface of the seventh lens to the imaging surface of the image sensor, D1 is a distance on the optical axis between the image side surface of the first lens and the object side surface of the second lens, and IMG HT is half of a diagonal length of the imaging surface of the image sensor.

[0096] FOV is a field of view of the optical imaging system, and Fno is an F number of the optical imaging system.

[0097] In the following description, the first lens to the seventh lens included in the optical imaging system of the exemplary embodiment will be described.

[0098] The first lens can have a positive refractive power. Also, the first lens can have a meniscus shape convex toward the object side. In other words, the first surface of the first lens can be convex, and the second surface of the first lens can be concave.

[0099] At least one of the first surface and the second surface of the first lens can be aspherical. For example, both surfaces of the first lens can be aspherical.

[0100] The second lens can have a negative refractive power. Also, the second lens can have a meniscus shape convex toward the object side. In other words, the first surface of the second lens can be convex, and the second surface of the second lens can be concave.

[0101] At least one of the first surface and the second surface of the second lens can be aspherical. For example, both surfaces of the second lens can be aspherical.

[0102] The third lens can have a positive refractive power. Also, both surfaces of the third lens can be convex. In other words, the first surface and the second surface of the third lens can be convex.

[0103] Alternatively, the third lens can have a meniscus shape convex toward the object side. In other words, the first surface of the third lens can be convex, and the second surface of the third lens can be concave.

[0104] At least one of the first surface and the second surface of the third lens can be aspherical. For example, both surfaces of the third lens can be aspherical.

[0105] The fourth lens can have a negative refractive power. Also, both surfaces of the fourth lens can be concave. In other words, the first surface and the second surface of the fourth lens can be concave.

[0106] At least one of the first surface and the second surface of the fourth lens can be aspherical. For example, both surfaces of the fourth lens can be aspherical.

[0107] The fifth lens can have a positive refractive power or a negative refractive power. Also, the fifth lens can have a meniscus shape convex toward the object side. In other words, the first surface of the fifth lens can be convex in the paraxial region, and the second surface of the fifth lens can be concave in the paraxial region.

[0108] At least one of the first surface and the second surface of the fifth lens can be aspherical. For example, both surfaces of the fifth lens can be aspherical.

[0109] The fifth lens can have at least one inflection point formed on at least one of the first surface and the second surface. For example, the first surface of the fifth lens can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. The second surface of the fifth lens can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0110] The sixth lens can have a positive refractive power. Also, the sixth lens can have a meniscus shape convex toward the object side. In other words, the first surface of the sixth lens can be convex in the paraxial region, and the second surface can be concave in the paraxial region.

[0111] At least one of the first surface and the second surface of the sixth lens can be aspherical. For example, both surfaces of the sixth lens can be aspherical.

[0112] The sixth lens can have at least one inflection point formed on at least one of the first surface and the second surface. For example, the first surface of the sixth lens can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. The second surface of the sixth lens can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0113] The seventh lens can have a negative refractive power. Also, both surfaces of the seventh lens can be concave. In other words, the first surface and the second surface of the seventh lens can be concave in the paraxial region.

[0114] At least one of the first surface and the second surface of the seventh lens can be aspherical. For example, both surfaces of the seventh lens can be aspherical.

[0115] At least one inflection point can be formed on at least one of the first surface and the second surface of the seventh lens. For example, the first surface of the seventh lens can be concave in the paraxial region, and can be convex in a portion other than the paraxial region. The second surface of the seventh lens can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0116] The first lens and the second lens can be formed of plastic materials having different optical properties from each other, and the second lens and the third lens can be formed of plastic materials having different optical properties from each other. Also, the first to third lenses can be formed of plastic materials having different optical properties from each other.

[0117] Meanwhile, at least three of the first to seventh lenses can have a refractive index greater than 1.64.

[0118] Further, at least two of the first to seventh lenses can have a refractive index greater than 1.66.

[0119] Among the first to fourth lenses, the lens having a negative refractive power can have a refractive index greater than 1.66. For example, the second lens and the fourth lens can have a negative refractive power and can have a refractive index greater than 1.66.

[0120] Further, among the first to fourth lenses, the lens disposed between the lenses having a refractive index greater than 1.66 can have a positive refractive power and can have a refractive index greater than 1.64. For example, the third lens can have a positive refractive power and a refractive index greater than 1.64.

[0121] Reference will be made to Figure 1 A first example of an optical imaging system will be described.

[0122] The optical imaging system of the first example can include an optical system including a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, and a seventh lens 170, and can further include a stop, a filter 180, and an image sensor 190.

[0123] The lens properties (radius of curvature, thickness of a lens or distance between lenses, refractive index, Abbe number, and focal length) of each lens are shown in Table 1 below.

[0124] [Table 1]

[0125]

[0126]

[0127] The focal length f of the optical imaging system of the first example is 6.17 mm, f12 is 8.10 mm, Fno is 2.1, FOV is 86.8°, and IMG HT is 6 mm.

[0128] f12 is a combined focal length of the first lens and the second lens, Fno is a number indicating brightness of the optical imaging system, FOV is a field of view of the optical imaging system, and IMG HT is half of a diagonal length of an imaging surface of the image sensor.

[0129] In the first example, the first lens 110 can have a positive refractive power, the first surface of the first lens 110 can be convex, and the second surface of the first lens 110 can be concave.

[0130] The second lens 120 can have a negative refractive power, the first surface of the second lens 120 can be convex, and the second surface of the second lens 120 can be concave.

[0131] The third lens 130 can have a positive refractive power, and the first and second surfaces of the third lens 130 can be convex.

[0132] The fourth lens 140 can have a negative refractive power, and the first and second surfaces of the fourth lens 140 can be concave.

[0133] The fifth lens 150 can have a positive refractive power, the first surface of the fifth lens 150 can be convex in a paraxial region, and the second surface of the fifth lens 150 can be concave in the paraxial region.

[0134] Further, at least one inflection point can be formed on at least one of the first and second surfaces of the fifth lens 150. For example, the first surface of the fifth lens 150 can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. Further, the second surface of the fifth lens 150 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0135] The sixth lens 160 can have a positive refractive power, the first surface of the sixth lens 160 can be convex in a paraxial region, and the second surface of the sixth lens 160 can be concave in the paraxial region.

[0136] At least one inflection point can be formed on at least one of the first and second surfaces of the sixth lens 160. For example, the first surface of the sixth lens 160 can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. Further, the second surface of the sixth lens 160 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0137] The seventh lens 170 can have a negative refractive power, and the first and second surfaces of the seventh lens 170 can be concave in a paraxial region.

[0138] At least one inflection point can be formed on at least one of the first surface and the second surface of the seventh lens 170. For example, the first surface of the seventh lens 170 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region. Also, the second surface of the seventh lens 170 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0139] Each surface of the first lens 110 to the seventh lens 170 can have the aspheric coefficients in Table 2. For example, the object side surface and the image side surface of each of the first lens 110 to the seventh lens 170 can be aspheric.

[0140] [Table 2]

[0141]

[0142]

[0143] Also, the optical imaging system as described in the first example above can have an aberration characteristic as shown in FIG. 12. Figure 2

[0144] A second example of an optical imaging system will be described with reference to Figure 3

[0145] The optical imaging system of the second example can include an optical system including a first lens 210, a second lens 220, a third lens 230, a fourth lens 240, a fifth lens 250, a sixth lens 260, and a seventh lens 270, and can further include a stop, a filter 280, and an image sensor 290.

[0146] The lens characteristics (curvature radius, thickness of the lens or distance between lenses, refractive index, Abbe number, and focal length) of each lens are shown in Table 3 below.

[0147] [Table 3]

[0148]

[0149] The focal length f of the optical imaging system of the second example is 6.14 mm, f12 is 8.06 mm, Fno is 2.09, FOV is 86.9°, and IMG HT is 6 mm.

[0150] The definitions of f12, Fno, FOV, and IMG HT are the same as in the first example.

[0151] In the second example, the first lens 210 can have a positive refractive power, the first surface of the first lens 210 can be convex, and the second surface of the first lens 210 can be concave. ​​

[0152] The second lens 220 can have a negative refractive power, the first surface of the second lens 220 can be convex, and the second surface of the second lens 220 can be concave.

[0153] The third lens 230 can have a positive refractive power, and the first and second surfaces of the third lens 230 can be convex.

[0154] The fourth lens 240 can have a negative refractive power, and the first and second surfaces of the fourth lens 240 can be concave.

[0155] The fifth lens 250 can have a positive refractive power, the first surface of the fifth lens 250 can be convex in a paraxial region, and the second surface of the fifth lens 250 can be concave in the paraxial region.

[0156] Further, at least one inflection point can be formed on at least one of the first and second surfaces of the fifth lens 250. For example, the first surface of the fifth lens 250 can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. Further, the second surface of the fifth lens 250 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0157] The sixth lens 260 can have a positive refractive power, the first surface of the sixth lens 260 can be convex in a paraxial region, and the second surface of the sixth lens 260 can be concave in the paraxial region.

[0158] At least one inflection point can be formed on at least one of the first and second surfaces of the sixth lens 260. For example, the first surface of the sixth lens 260 can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. Further, the second surface of the sixth lens 260 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0159] The seventh lens 270 can have a negative refractive power, and the first and second surfaces of the seventh lens 270 can be concave in a paraxial region.

[0160] At least one inflection point can be formed on at least one of the first and second surfaces of the seventh lens 270. For example, the first surface of the seventh lens 270 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region. Further, the second surface of the seventh lens 270 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0161] Each surface of the first lens 210 to the seventh lens 270 may have the aspheric coefficients listed in Table 4. For example, the object-side surface and the image-side surface of each of the first lens 210 to the seventh lens 270 may be aspherical.

[0162] [Table 4]

[0163]

[0164]

[0165] Furthermore, the optical imaging system described in the second example above can have, for example, the following features: Figure 4 The aberration characteristics shown.

[0166] Reference Figure 5 A third example describing an optical imaging system.

[0167] The optical imaging system of the third example may include an optical system comprising a first lens 310, a second lens 320, a third lens 330, a fourth lens 340, a fifth lens 350, a sixth lens 360, and a seventh lens 370, and may also include an aperture, a filter 380, and an image sensor 390.

[0168] The lens characteristics of each lens (radius of curvature, lens thickness or distance between lenses, refractive index, Abbe number, and focal length) are shown in Table 5 below.

[0169] [Table 5]

[0170]

[0171]

[0172] The third example optical imaging system has a focal length of 6.14 mm, an f12 of 8.05 mm, an Fno of 2.07, an FOV of 86.8°, and an IMG HT of 6 mm.

[0173] The definitions of f12, Fno, FOV, and IMG HT are the same as in the first example.

[0174] In the third example, the first lens 310 may have positive refractive power, the first surface of the first lens 310 may be convex, and the second surface of the first lens 310 may be concave.

[0175] The second lens 320 may have negative refractive power, the first surface of the second lens 320 may be convex, and the second surface of the second lens 320 may be concave.

[0176] The third lens 330 can have a positive refractive power, and the first and second surfaces of the third lens 330 can be convex.

[0177] The fourth lens 340 can have a negative refractive power, and the first and second surfaces of the fourth lens 340 can be concave.

[0178] The fifth lens 350 can have a positive refractive power, the first surface of the fifth lens 350 can be convex in the paraxial region, and the second surface of the fifth lens 350 can be concave in the paraxial region.

[0179] In addition, at least one inflection point can be formed on at least one of the first and second surfaces of the fifth lens 350. For example, the first surface of the fifth lens 350 can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. In addition, the second surface of the fifth lens 350 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0180] The sixth lens 360 can have a positive refractive power, the first surface of the sixth lens 360 can be convex in the paraxial region, and the second surface of the sixth lens 360 can be concave in the paraxial region.

[0181] At least one inflection point can be formed on at least one of the first and second surfaces of the sixth lens 360. For example, the first surface of the sixth lens 360 can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. In addition, the second surface of the sixth lens 360 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0182] The seventh lens 370 can have a negative refractive power, and the first and second surfaces of the seventh lens 370 can be concave in the paraxial region.

[0183] At least one inflection point can be formed on at least one of the first and second surfaces of the seventh lens 370. For example, the first surface of the seventh lens 370 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region. In addition, the second surface of the seventh lens 370 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0184] Each surface of the first to seventh lenses 310 to 370 can have the aspheric coefficients in Table 6. For example, the object side surface and the image side surface of each of the first to seventh lenses 310 to 370 can be aspheric.

[0185] [Table 6]

[0186]

[0187]

[0188] Further, the optical imaging system as described in the third example above can have an aberration characteristic as shown in FIG. 13. Figure 6

[0189] A fourth example of an optical imaging system will be described with reference to FIG. 14. Figure 7

[0190] The optical imaging system of the fourth example can include an optical system including a first lens 410, a second lens 420, a third lens 430, a fourth lens 440, a fifth lens 450, a sixth lens 460, and a seventh lens 470, and can further include a stop, a filter 480, and an image sensor 490.

[0191] The lens characteristics (radius of curvature, thickness of the lens or distance between the lenses, refractive index, Abbe number, and focal length) of each lens are shown in Table 7 below.

[0192] [Table 7]

[0193]

[0194]

[0195] The focal length f of the optical imaging system of the fourth example is 6.09 mm, f12 is 7.91 mm, Fno is 2.08, FOV is 87.3°, and IMG HT is 6 mm.

[0196] The definitions of f12, Fno, FOV, and IMG HT are the same as in the first example.

[0197] In the fourth example, the first lens 410 can have a positive refractive power, the first surface of the first lens 410 can be convex, and the second surface of the first lens 410 can be concave.

[0198] The second lens 420 can have a negative refractive power, the first surface of the second lens 420 can be convex, and the second surface of the second lens 420 can be concave.

[0199] The third lens 430 can have a positive refractive power, and the first and second surfaces of the third lens 430 can be convex.

[0200] The fourth lens 440 can have a negative refractive power, and the first and second surfaces of the fourth lens 440 can be concave.

[0201] ​​The fifth lens 450 can have a positive refractive power, the first surface of the fifth lens 450 can be convex in the paraxial region, and the second surface of the fifth lens 450 can be concave in the paraxial region.

[0202] Further, at least one inflection point can be formed on at least one of the first surface and the second surface of the fifth lens 450. For example, the first surface of the fifth lens 450 can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. Further, the second surface of the fifth lens 450 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0203] The sixth lens 460 can have a positive refractive power, the first surface of the sixth lens 460 can be convex in the paraxial region, and the second surface of the sixth lens 460 can be concave in the paraxial region.

[0204] At least one inflection point can be formed on at least one of the first surface and the second surface of the sixth lens 460. For example, the first surface of the sixth lens 460 can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. Further, the second surface of the sixth lens 460 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0205] The seventh lens 470 can have a negative refractive power, and the first surface and the second surface of the seventh lens 470 can be concave in the paraxial region.

[0206] At least one inflection point can be formed on at least one of the first surface and the second surface of the seventh lens 470. For example, the first surface of the seventh lens 470 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region. Further, the second surface of the seventh lens 470 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0207] Each surface of the first lens 410 to the seventh lens 470 can have the aspherical coefficients in Table 8. For example, the object side surface and the image side surface of each of the first lens 410 to the seventh lens 470 can be aspherical.

[0208] [Table 8]

[0209]

[0210]

[0211] Further, the optical imaging system as described in the fourth example above can have an aberration characteristic as shown in FIG. 17. Figure 8

[0212] ​Reference will be made to Figure 9 A fifth example of an optical imaging system is described.

[0213] The optical imaging system of the fifth example can include an optical system including a first lens 510, a second lens 520, a third lens 530, a fourth lens 540, a fifth lens 550, a sixth lens 560, and a seventh lens 570, and can further include a stop, a filter 580, and an image sensor 590.

[0214] The lens properties (radius of curvature, thickness of a lens or distance between lenses, refractive index, Abbe number, and focal length) of each lens are shown in Table 9 below.

[0215] [Table 9]

[0216]

[0217] The focal length f of the optical imaging system of the fifth example is 6.01 mm, f12 is 8 mm, Fno is 2.06, FOV is 88°, and IMG HT is 6 mm.

[0218] The definitions of f12, Fno, FOV, and IMG HT are the same as in the first example.

[0219] In the fifth example, the first lens 510 can have a positive refractive power, the first surface of the first lens 510 can be convex, and the second surface of the first lens 510 can be concave.

[0220] The second lens 520 can have a negative refractive power, the first surface of the second lens 520 can be convex, and the second surface of the second lens 520 can be concave.

[0221] The third lens 530 can have a positive refractive power, and the first surface of the third lens 530 can be convex, and the second surface of the third lens 530 can be concave.

[0222] The fourth lens 540 can have a negative refractive power, and the first and second surfaces of the fourth lens 540 can be concave.

[0223] The fifth lens 550 can have a negative refractive power, the first surface of the fifth lens 550 can be convex in a paraxial region, and the second surface of the fifth lens 550 can be concave in the paraxial region.

[0224] Further, at least one inflection point can be formed on at least one of the first and second surfaces of the fifth lens 550. For example, the first surface of the fifth lens 550 can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. Further, the second surface of the fifth lens 550 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0225] The sixth lens 560 can have a positive refractive power, the first surface of the sixth lens 560 can be convex in the paraxial region, and the second surface of the sixth lens 560 can be concave in the paraxial region.

[0226] At least one inflection point can be formed on at least one of the first and second surfaces of the sixth lens 560. For example, the first surface of the sixth lens 560 can be convex in the paraxial region, and can be concave in a portion other than the paraxial region. Further, the second surface of the sixth lens 560 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0227] The seventh lens 570 can have a negative refractive power, and the first and second surfaces of the seventh lens 570 can be concave in the paraxial region.

[0228] At least one inflection point can be formed on at least one of the first and second surfaces of the seventh lens 570. For example, the first surface of the seventh lens 570 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region. Further, the second surface of the seventh lens 570 can be concave in the paraxial region, and can be convex in a portion other than the paraxial region.

[0229] Each surface of the first to seventh lenses 510 to 570 can have the aspherical coefficients in Table 10. For example, the object side surface and the image side surface of each of the first to seventh lenses 510 to 570 can be aspherical.

[0230] [Table 10]

[0231]

[0232]

[0233] Further, the optical imaging system as described in the fifth example above can have an aberration characteristic as shown in FIG. 17. Figure 10

[0234] Table 11 lists the values of the conditional expressions of the optical imaging systems of the first to fifth examples.

[0235] [Table 11]

[0236] ​

[0237]

[0238] According to the above exemplary embodiments, the optical imaging system can achieve high resolution and can have a reduced size.

[0239] While specific examples have been shown and described, it will be apparent to those skilled in the art having the benefit of this disclosure that changes can be made in form and details without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered illustrative, and not restrictive, in nature. The description of features or aspects in each example should be considered applicable to similar features or aspects in other examples. Suitable results can be obtained if the described techniques are performed in a different order, and / or if components in the described systems, architectures, devices, or circuits are combined in a different manner, and / or replaced or supplemented by other components or their equivalents. Accordingly, the scope of the disclosure is not limited to the specific embodiments described herein, but only by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.

Claims

1. An optical imaging system, comprising: The first lens has positive refractive power, a convex object-side surface and a concave image-side surface; The second lens has negative refractive power, with a convex object side and a concave image side; The third lens has positive refractive power; The fourth lens has negative refractive power and a concave image-side surface; The fifth lens has positive refractive power; The sixth lens has refractive power, with a convex object-side surface and a concave image-side surface; as well as The seventh lens has negative refractive power. The first lens to the seventh lens are arranged sequentially from the object side. The optical imaging system has a total of seven lenses. Wherein, 0 < f1 / f < 1.8, -4 < f2 / f < -1, 3 < f3 / f ≤ 5.893, and |f4 / f| > 3 are satisfied, where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, and f is the focal length of the optical imaging system.

2. The optical imaging system according to claim 1, wherein, The condition is satisfied that 1 < f12 / f < 2, where f12 is the combined focal length of the first lens and the second lens.

3. The optical imaging system according to claim 1, wherein, The condition is satisfied that |f1 / f2| < 1.

4. The optical imaging system according to claim 1, wherein, The condition is satisfied that -2 < f2 / f3 < 0.

5. The optical imaging system according to claim 1, wherein, The following condition must be met: -2 < f7 / f < 0, where f7 is the focal length of the seventh lens.

6. The optical imaging system according to claim 1, wherein, The following condition is satisfied: 25 < v1 - v2 < 45, where v1 is the Abbe number of the first lens and v2 is the Abbe number of the second lens.

7. The optical imaging system according to claim 6, wherein, The condition is satisfied that v1-v3 < 35, where v3 is the Abbe number of the third lens.

8. The optical imaging system according to claim 1, wherein, The condition D1 / f < 0.1 is satisfied, where D1 is the distance on the optical axis from the image-side surface of the first lens to the object-side surface of the second lens.

9. The optical imaging system according to claim 1, wherein, The condition BFL / f < 0.3 is satisfied, where BFL is the distance on the optical axis from the image-side surface of the seventh lens to the imaging surface.

10. The optical imaging system according to claim 1, wherein, The third lens has a convex image-side surface.

11. The optical imaging system according to claim 10, wherein, The third lens has a convex object-side surface.

12. The optical imaging system according to claim 1, wherein, The fourth lens has a concave object-side surface.

13. The optical imaging system according to claim 1, wherein, The seventh lens has a concave image-side surface.

14. The optical imaging system according to claim 1, wherein, At least three of the first to seventh lenses have a refractive index greater than 1.

64.

15. The optical imaging system according to claim 10, wherein, At least two of the first to the seventh lenses have a refractive index greater than 1.

66.

16. The optical imaging system according to claim 1, wherein, The second lens and the fourth lens have a refractive index greater than 1.66.

Images