Optical imaging system

Abstract

An optical imaging system includes, in order along an optical axis from an object side of the optical imaging system toward an imaging surface of an image sensor, 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)≤0.67 is satisfied, where TTL is a distance along the optical axis from an object side surface of the first lens to the imaging surface of the image sensor, and IMG HT is half of a diagonal length of the imaging surface of the image sensor, and 15

Description

[0001] Cross-reference to Related Applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0068432, filed on Jun. 5, 2020, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. Technical Field

[0003] This application relates to an optical imaging system. Background Art

[0004] Portable terminal devices have been designed to include a camera that includes an optical imaging system including a plurality of lenses to allow video calls and the taking of images and videos of objects.

[0005] As the functions of cameras in portable terminal devices increase, there is an increasing demand for cameras used in portable terminal devices to have high resolution.

[0006] Since portable terminal devices have been designed to have a reduced size, it is necessary for cameras used in portable terminal devices to have a reduced size.

[0007] Therefore, it is necessary to develop an optical imaging system having a reduced size and high resolution. Summary of the Invention

[0008] This summary is provided to introduce some concepts 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 help determine the scope of the claimed subject matter.

[0009] In one general aspect, an optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially arranged in ascending numerical order along an optical axis from an object side of the optical imaging system toward an imaging surface of an image sensor, where TTL / (2*IMG HT)≤0.67, where TTL is the distance along the optical axis from an object surface of the first lens to the imaging surface of the image sensor, and IMG HT is half of the diagonal length of the imaging surface of the image sensor, and 15<v1 - v3<45, where v1 is the Abbe number of the first lens, and v3 is the Abbe number of the third lens.

[0010] It can satisfy any one or any combination of two or more of 25 < v1 - v2 < 45, 25 < v1 - v4 < 45, and 15 < v1 - v5 < 45, where v2 is the Abbe number of the second lens, v4 is the Abbe number of the fourth lens, and v5 is the Abbe number of the fifth lens.

[0011] It can satisfy Fno < 2.0, where Fno is the f - number of the optical imaging system.

[0012] It can satisfy 0 < f1 / f < 2, where f1 is the focal length of the first lens and f is the focal length of the optical imaging system.

[0013] It can satisfy - 3.5 < f2 / f < 0, where f2 is the focal length of the second lens and f is the focal length of the optical imaging system.

[0014] It can satisfy f3 / f > 1.5, where f3 is the focal length of the third lens and f is the focal length of the optical imaging system.

[0015] It can satisfy - 9 < f4 / f < 0, where f4 is the focal length of the fourth lens and f is the focal length of the optical imaging system.

[0016] It can satisfy - 30 < f5 / f < 20, where f5 is the focal length of the fifth lens and f is the focal length of the optical imaging system.

[0017] It can satisfy TTL / f < 1.4, where f is the focal length of the optical imaging system, and it can satisfy BFL / f < 0.4, where BFL is the distance along the optical axis from the image side of the seventh lens to the imaging surface of the image sensor.

[0018] It can satisfy - 1 < f1 / f2 < 0, where f1 is the focal length of the first lens and f2 is the focal length of the second lens.

[0019] It can satisfy - 2 < f2 / f3 < 0, where f2 is the focal length of the second lens and f3 is the focal length of the third lens.

[0020] It can satisfy D1 / f < 0.3, where D1 is the distance along the optical axis from the image side of the first lens to the object side of the second lens, and f is the focal length of the optical imaging system.

[0021] It can satisfy 0.4 < SD5 / IMG HT < 0.7, where SD5 is the effective aperture radius of the image side of the fifth lens.

[0022] It can satisfy 0.6 < SD6 / IMG HT < 0.8, where SD6 is the effective aperture radius of the image side of the sixth lens.

[0023] It can satisfy 0.7 < SD7 / IMG HT < 1, where SD7 is the effective aperture radius of the image side of the seventh lens.

[0024] It can satisfy -5 < f2 / f6 < 0, where f2 is the focal length of the second lens and f6 is the focal length of the sixth lens.

[0025] It can satisfy 0 < f2 / f7 < 5, where f2 is the focal length of the second lens and f7 is the focal length of the seventh lens.

[0026] It can satisfy 0 < f6 / f < 2, where f6 is the focal length of the sixth lens and f is the focal length of the optical imaging system.

[0027] It can satisfy -2 < f7 / f < 0, where f7 is the focal length of the seventh lens and f is the focal length of the optical imaging system.

[0028] It can satisfy 74° < FOV < 90°, where FOV is the field of view of the optical imaging system.

[0029] It can satisfy 1 < f12 / f < 2, where f12 is the combined focal length of the first lens and the second lens and f is the focal length of the optical imaging system.

[0030] 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 fifth 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.

[0031] In another general aspect, the optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially arranged in ascending numerical order along the optical axis from the object side of the optical imaging system toward the imaging surface of the image sensor, where 15 < v1 - v3 < 45 is satisfied, where v1 is the Abbe number of the first lens and v3 is the Abbe number of the third lens.

[0032] All of 25 < v1 - v2 < 45, 25 < v1 - v4 < 45, and 15 < v1 - v5 < 45 can be satisfied, where v2 is the Abbe number of the second lens, v4 is the Abbe number of the fourth lens, and v5 is the Abbe number of the fifth lens.

[0033] 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 fifth 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.

[0034] The first lens may have a convex object side and a concave image side; the second lens may have a convex object side and a concave image side; the fourth lens may have a convex object side and a concave image side; the fifth lens may have a convex object side and a concave image side; the sixth lens may have a convex object side and a concave image side; and the seventh lens may have a concave image side.

[0035] Other features and aspects will be apparent from the following detailed description, drawings and claims. Attached Figure Description

[0036] Figure 1 This is a diagram illustrating a first example of an optical imaging system.

[0037] Figure 2 It is shown Figure 1 The diagram shows the aberration characteristics of the optical imaging system.

[0038] Figure 3 This is a diagram illustrating a second example of an optical imaging system.

[0039] Figure 4 It is shown Figure 3 The diagram shows the aberration characteristics of the optical imaging system.

[0040] Figure 5 This is a diagram illustrating a third example of an optical imaging system.

[0041] Figure 6 It is shown Figure 5 The diagram shows the aberration characteristics of the optical imaging system.

[0042] Figure 7 This is a diagram illustrating a fourth example of an optical imaging system.

[0043] Figure 8 It is shown Figure 7 The diagram shows the aberration characteristics of the optical imaging system.

[0044] Figure 9 This is a diagram illustrating the fifth example of an optical imaging system.

[0045] Figure 10 It is shown Figure 9 The diagram shows the aberration characteristics of the optical imaging system.

[0046] Throughout the accompanying drawings and detailed description, 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 description of the elements in the drawings may be exaggerated. Detailed Implementation

[0047] The following detailed description is provided to aid 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 upon understanding the disclosure of this application. For example, the sequence of operations described herein is merely illustrative and is not limited to the sequence set forth herein, but may be changed as will be apparent upon understanding the disclosure of this application, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of functions and structures known in the art may be omitted.

[0048] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways of implementing the methods, apparatus, and / or systems described herein that will become apparent upon understanding the disclosure of this application.

[0049] The term “may” is used in this document with respect to examples or embodiments, such as what an example or embodiment may include or implement, meaning that there exists at least one example or embodiment that includes or implements such a feature, but not all examples and embodiments are limited thereto.

[0050] Throughout the 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," "directly connected to," or "directly attached to" the other element, or there may be one or more other elements in between. Conversely, when an element is described as being "directly on," "directly connected to," or "directly attached to" another element, there are no other elements in between.

[0051] As used herein, the term “and / or” includes any one of the associated listed items and any combination of any two or more.

[0052] Although terms such as "first," "second," and "third" may be used to describe various elements in this document, these elements are not limited by these terms. Rather, these terms are used only to distinguish one element from another. Therefore, without departing from the teachings of the examples, the first element involved in the examples described herein may also be referred to as the second element.

[0053] Spatially 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, these spatially relative terms are intended to also include different orientations of the device during use or operation. For example, if the device in the figures is flipped, an element described as “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to said other element. Thus, depending on the spatial orientation of the device, the term “above” includes both upper and lower orientations. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein will be interpreted accordingly.

[0054] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the articles “a,” “an,” and “the” are intended to include the plural form as well. The terms “comprise,” “include,” and “have” indicate the presence of the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0055] As will be apparent upon understanding the disclosure of this application, the features of the examples described herein can be combined in various ways. Furthermore, although the examples described herein have multiple configurations, other configurations are also possible, as will be apparent upon understanding the disclosure of this application.

[0056] Due to manufacturing techniques and / or tolerances, variations in the shape shown in the figures may occur. Therefore, the examples described herein are not limited to the specific shapes shown in the figures, but include variations in shape that occur during manufacturing.

[0057] In the accompanying drawings, the thickness, size, and shape of the lenses may be exaggerated for clarity and ease of illustration. The shapes of the spherical or aspherical surfaces of the lenses in the drawings are merely examples, and the spherical or aspherical surfaces are not limited to these shapes.

[0058] The optical imaging system according to this application may include seven lenses.

[0059] For example, an optical imaging system may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged in ascending numerical order along the optical axis from the object side of the optical imaging system toward the imaging surface of the optical imaging system. The first to seventh lenses may be spaced apart from each other at a predetermined distance along the optical axis.

[0060] Therefore, the first lens is the lens closest to the object side of the optical imaging system, and the seventh lens is the lens closest to the imaging surface of the optical imaging system.

[0061] In each lens, the first surface or object side is the surface closest to the object side of the optical imaging system, and the second surface or image side is the surface closest to the imaging surface of the optical imaging system.

[0062] The radius of curvature of the lens surface, the thickness of the lens and other elements, the distance between the lens and other elements, the focal length, TTL, BFL, IMG HT, SD5, SD6, and SD7 are expressed in millimeters (mm), the FOV is expressed in degrees (°), and Fno, refractive power, and Abbe number are dimensionless values. These named values ​​will be defined later in this application.

[0063] The thickness of the lens and other components, the distance between the lens and other components, TTL, and BFL are measured along the optical axis of the optical imaging system.

[0064] Unless otherwise stated, the shape of a lens surface refers to the shape of the paraxial region of the lens surface. The paraxial region of a lens surface is the central portion of the lens surface surrounding the optical axis, in which light rays incident on the lens surface form a small angle θ with the optical axis, and the approximations sinθ≈θ and tanθ≈θ are valid.

[0065] For example, the statement that the surface of a lens is convex, concave, or flat means that at least the paraxial region of the lens surface is convex, concave, or flat. Therefore, even if the surface of a lens is described as convex, the peripheral region of the lens surface may be concave or flat. Furthermore, even if the surface of a lens is described as concave, the peripheral region of the lens surface may be convex or flat. Additionally, even if the surface of a lens is described as flat, the peripheral region of the lens surface may be convex or concave.

[0066] As described above, the optical imaging system according to this application may include a first lens to a seventh lens. However, the optical imaging system is not limited to only seven lenses, but may also include other elements if necessary.

[0067] For example, an optical imaging system may also include an image sensor for converting an image of an object incident on the imaging surface of the image sensor into an electrical signal.

[0068] In addition, the optical imaging system may also include an infrared filter (hereinafter referred to as a filter) for blocking infrared light. The filter may be positioned between the seventh lens and the image sensor.

[0069] In addition, the optical imaging system may also include an aperture for adjusting the amount of light incident on the imaging surface of the image sensor.

[0070] The first lens to the seventh lens may be made of a plastic material.

[0071] In addition, at least one of the first lens to the seventh lens may have an aspherical surface. For example, each of the first lens to the seventh lens may have at least one aspherical surface.

[0072] In other words, at least one of the first surface and the second surface of each of the first lens to the seventh lens may be aspherical. Each aspherical surface of the first lens to the seventh lens is defined by Equation 1 below.

[0073]

[0074] In Equation 1, c is the curvature of the lens surface and is equal to the reciprocal of the radius of curvature of the lens surface at the optical axis of the lens surface, K is the conic constant, Y is the distance from any point on the lens surface to the optical axis of the lens surface in a direction perpendicular to the optical axis of the lens surface, A to H and J are aspherical constants, and Z (also known as the sag) is the distance from a point on the lens surface at a distance Y from the optical axis of the lens surface in a direction parallel to the optical axis of the lens surface to a tangent plane perpendicular to the optical axis and intersecting the vertex of the lens surface.

[0075] The first lens to the seventh lens may have positive refractive power, negative refractive power, positive refractive power, negative refractive power, negative refractive power, positive refractive power, and negative refractive power, respectively.

[0076] The optical imaging system may satisfy any one or any combination of any two or more of the following conditional expressions 1 to 25:

[0077] 0 < f1 / f < 2 (conditional expression 1)

[0078] 25 < v1 - v2 < 45 (conditional expression 2)

[0079] 15 < v1 - v3 < 45 (conditional expression 3)

[0080] 25 < v1 - v4 < 45 (conditional expression 4)

[0081] 15 < v1 - v5 < 45 (conditional expression 5)

[0082] -3.5 < f2 / f < 0 (conditional expression 6)

[0083] f3 / f > 1.5 (conditional expression 7)

[0084] -9 < f4 / f < 0 (conditional expression 8)

[0085] -30 < f5 / f < 20 (Conditional Expression 9)

[0086] 0 < f6 / f < 2 (Conditional Expression 10)

[0087] -2 < f7 / f < 0 (Conditional Expression 11)

[0088] TTL / f < 1.4 (Conditional Expression 12)

[0089] -1 < f1 / f2 < 0 (Conditional Expression 13)

[0090] -2 < f2 / f3 < 0 (Conditional Expression 14)

[0091] BFL / f < 0.4 (Conditional Expression 15)

[0092] D1 / f < 0.3 (Conditional Expression 16)

[0093] 0.4 < SD5 / IMG HT < 0.7 (Conditional Expression 17)

[0094] 0.6 < SD6 / IMG HT < 0.8 (Conditional Expression 18)

[0095] 0.7 < SD7 / IMG HT < 1 (Conditional Expression 19)

[0096] 0 < f2 / f7 < 5 (Conditional Expression 20)

[0097] -5 < f2 / f6 < 0 (Conditional Expression 21)

[0098] 74° < FOV < 90° (Conditional Expression 22)

[0099] Fno < 2.0 (Conditional Expression 23)

[0100] TTL / (2 * IMG HT) ≤ 0.67 (Conditional Expression 24)

[0101] 1 < f12 / f < 2 (Conditional Expression 25)

[0102] In Conditional Expressions 1 to 25, f is the focal length of the optical imaging system, 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, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, and f12 is the combined focal length of the first lens and the second lens.

[0103] v1 is the Abbe number of the first lens, v2 is the Abbe number of the second lens, v3 is the Abbe number of the third lens, v4 is the Abbe number of the fourth lens, and v5 is the Abbe number of the fifth lens.

[0104] TTL is the distance along the optical axis from the object side of the first lens to the imaging surface of the image sensor; BFL is the distance along the optical axis from the image side of the seventh lens to the imaging surface of the image sensor; D1 is the distance along the optical axis between the image side of the first lens and the object side of the second lens; and IMG HT is half the diagonal length of the imaging surface of the image sensor.

[0105] FOV is the field of view of the optical imaging system, and Fno is the f-number of the optical imaging system, which is equal to the focal length f of the optical imaging system divided by the entrance pupil diameter of the optical imaging system, and represents the brightness of the optical imaging system.

[0106] SD5 is the effective aperture radius of the image-side surface of the fifth lens, SD6 is the effective aperture radius of the image-side surface of the sixth lens, and SD7 is the effective aperture radius of the image-side surface of the seventh lens.

[0107] The effective aperture radius of a lens surface is the radius of the portion of the lens surface that light actually passes through, and it is not necessarily the radius of the outer edge of the lens surface. The object-side surface and the image-side surface of a lens can have different effective aperture radii.

[0108] In other words, the effective aperture radius of a lens surface is the distance between the optical axis of the lens surface and the edge ray of light passing through the lens surface in a direction perpendicular to the optical axis of the lens surface.

[0109] The first lens may have positive refractive power. Furthermore, the first lens may have a meniscus shape that is convex toward the object side of the optical imaging system. In other words, the first surface of the first lens may be convex, and the second surface of the first lens may be concave.

[0110] At least one of the first surface and the second surface of the first lens can be an aspherical surface. For example, both surfaces of the first lens can be aspherical surfaces.

[0111] The second lens can have negative refractive power. Furthermore, the second lens can have a meniscus shape that is convex towards the object side of the optical imaging system. In other words, the first surface of the second lens can be convex, and the second surface of the second lens can be concave.

[0112] At least one of the first and second surfaces of the second lens can be aspherical. For example, both surfaces of the second lens can be aspherical.

[0113] The third lens can have positive refractive power. Furthermore, the third lens can have a meniscus shape that is convex towards the image side of the optical imaging system. In other words, the first surface of the third lens can be concave, and the second surface of the third lens can be convex.

[0114] Alternatively, both surfaces of the third lens can be convex. In other words, the first and second surfaces of the third lens can be convex.

[0115] Alternatively, the third lens may have a meniscus shape that is convex toward the object side of the optical imaging system. In other words, the first surface of the third lens may be convex, and the second surface of the third lens may be concave.

[0116] At least one of the first and second surfaces of the third lens can be aspherical. For example, both surfaces of the third lens can be aspherical.

[0117] The fourth lens can have negative refractive power. Furthermore, the fourth lens can have a meniscus shape that is convex towards the object side of the optical imaging system. In other words, the first surface of the fourth lens can be convex, and the second surface of the third lens can be concave.

[0118] At least one of the first and second surfaces of the fourth lens can be aspherical. For example, both surfaces of the fourth lens can be aspherical.

[0119] The fifth lens can have negative refractive power. Furthermore, the fifth lens can have a meniscus shape that is convex towards the object side of the optical imaging system. 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.

[0120] At least one of the first and second surfaces of the fifth lens can be aspherical. For example, both surfaces of the fifth lens can be aspherical.

[0121] The fifth lens may have at least one inflection point formed on at least one of the first and second surfaces. For example, the first surface of the fifth lens may be convex in the paraxial region and concave in the portion other than the paraxial region. The second surface of the fifth lens may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0122] The sixth lens can have positive refractive power. Furthermore, the sixth lens can have a meniscus shape that is convex towards the object side of the optical imaging system. 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.

[0123] At least one of the first and second surfaces of the sixth lens can be aspherical. For example, both surfaces of the sixth lens can be aspherical.

[0124] The sixth lens may have at least one inflection point formed on at least one of the first and second surfaces. For example, the first surface of the sixth lens may be convex in the paraxial region and concave in the portion other than the paraxial region. The second surface of the sixth lens may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0125] The seventh lens can have negative refractive power. Furthermore, the seventh lens can have a meniscus shape that is convex towards the object side of the optical imaging system. In other words, the first surface of the seventh lens can be convex in the paraxial region, and the second surface can be concave in the paraxial region.

[0126] Alternatively, both surfaces of the seventh lens can be concave. In other words, the first and second surfaces of the seventh lens can be concave in the paraxial region.

[0127] At least one of the first and second surfaces of the seventh lens can be aspherical. For example, both surfaces of the seventh lens can be aspherical.

[0128] At least one inflection point may be formed on at least one of the first and second surfaces of the seventh lens. For example, the first surface of the seventh lens may be convex in the paraxial region and concave in the portion other than the paraxial region. The second surface of the seventh lens may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0129] The first and second lenses can be made of plastic materials with different optical properties, and the second and third lenses can also be made of plastic materials with different optical properties. Furthermore, the first to third lenses can be made of plastic materials with different optical properties.

[0130] At least two of the first through seventh lenses may have a refractive index greater than 1.66.

[0131] Among the first through fourth lenses, lenses with negative refractive power can have a refractive index greater than 1.66. For example, the second and fourth lenses can have negative refractive power and a refractive index greater than 1.66.

[0132] Figure 1 This is a diagram illustrating a first example of an optical imaging system, and Figure 2 It is shown Figure 1 The diagram shows the aberration characteristics of the optical imaging system.

[0133] The optical imaging system of the first example may include an optical system comprising 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 may also include an aperture (not shown), a filter 180, and an image sensor 190.

[0134] The optical properties of each element in the optical imaging system (radius of curvature of each surface of the element, thickness of the element or distance between the element and the next element, refractive index, Abbe number and focal length) are listed in Table 1 below.

[0135] Table 1

[0136]

[0137] The first example optical imaging system has a focal length of 5.74564 mm for f12, 7.3574 mm for f12, 1.75 for f16, 83° for FOV, 5.272 mm for IMG HT, 2.51 mm for SD5, 3.804 mm for SD6, and 4.4013 mm for SD7.

[0138] f12 is the combined focal length of the first and second lenses, Fno is the f-number of the optical imaging system, which is equal to the focal length f of the optical imaging system divided by the entrance pupil diameter of the optical imaging system, and represents the brightness of the optical imaging system, FOV is the field of view of the optical imaging system, IMG HT is half the diagonal length of the image plane of the image sensor, SD5 is the effective aperture radius of the image side of the fifth lens, SD6 is the effective aperture radius of the image side of the sixth lens, and SD7 is the effective aperture radius of the image side of the seventh lens.

[0139] In the first example, 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.

[0140] 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.

[0141] The third lens 130 may have positive refractive power, the first surface of the third lens 130 may be concave, and the second surface of the third lens 130 may be convex.

[0142] The fourth lens 140 may have negative refractive power, the first surface of the fourth lens 140 may be convex, and the second surface of the fourth lens 140 may be concave.

[0143] The fifth lens 150 may have negative refractive power, the first surface of the fifth lens 150 may be convex in the paraxial region, and the second surface of the fifth lens 150 may be concave in the paraxial region.

[0144] Furthermore, at least one inflection point may 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 may be convex in the paraxial region and concave in the portion other than the paraxial region. Similarly, the second surface of the fifth lens 150 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0145] The sixth lens 160 may have positive refractive power, the first surface of the sixth lens 160 may be convex in the paraxial region, and the second surface of the sixth lens 160 may be concave in the paraxial region.

[0146] At least one inflection point may 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 may be convex in the paraxial region and concave in the portion other than the paraxial region. Furthermore, the second surface of the sixth lens 160 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0147] The seventh lens 170 may have negative refractive power, the first surface of the seventh lens 170 may be convex in the paraxial region, and the second surface of the seventh lens 170 may be concave in the paraxial region.

[0148] At least one inflection point may be formed on at least one of the first and second surfaces of the seventh lens 170. For example, the first surface of the seventh lens 170 may be convex in the paraxial region and concave in the portion other than the paraxial region. Furthermore, the second surface of the seventh lens 170 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0149] Each surface of the first lens 110 to the seventh lens 170 has aspherical coefficients listed in Table 2 below. In this example, the first and second surfaces of each of the first lens 110 to the seventh lens 170 are aspherical.

[0150] Table 2

[0151]

[0152] The optical imaging system with the above configuration has Figure 2 The aberration characteristics shown are illustrated.

[0153] Figure 3This is a diagram illustrating a second example of an optical imaging system, and Figure 4 It is shown Figure 3 The diagram shows the aberration characteristics of the optical imaging system.

[0154] The optical imaging system of the second example may include an optical system comprising 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 may also include an aperture (not shown), a filter 280, and an image sensor 290.

[0155] The optical properties of each element in the optical imaging system (radius of curvature of each surface of the element, thickness of the element or distance between the element and the next element, refractive index, Abbe number and focal length) are listed in Table 3 below.

[0156] Table 3

[0157]

[0158] The second example optical imaging system has a focal length of 6.21249 mm, f12 of 7.53789 mm, Fno of 1.88, FOV of 83°, IMG HT of 5.644 mm, SD5 of 2.55 mm, SD6 of 3.85354 mm, and SD7 of 5.1063 mm.

[0159] The definitions of f12, Fno, FOV, IMG HT, SD5, SD6, and SD7 are the same as in the first example.

[0160] 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.

[0161] 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.

[0162] The third lens 230 may have positive refractive power, and the first and second surfaces of the third lens 230 may be convex.

[0163] The fourth lens 240 may have negative refractive power, the first surface of the fourth lens 240 may be convex, and the second surface of the fourth lens 240 may be concave.

[0164] The fifth lens 250 may have negative refractive power, the first surface of the fifth lens 250 may be convex in the paraxial region, and the second surface of the fifth lens 250 may be concave in the paraxial region.

[0165] Furthermore, at least one inflection point may 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 may be convex in the paraxial region and concave in the portion other than the paraxial region. Similarly, the second surface of the fifth lens 250 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0166] The sixth lens 260 may have positive refractive power, the first surface of the sixth lens 260 may be convex in the paraxial region, and the second surface of the sixth lens 260 may be concave in the paraxial region.

[0167] At least one inflection point may 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 may be convex in the paraxial region and concave in the portion other than the paraxial region. Furthermore, the second surface of the sixth lens 260 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0168] The seventh lens 270 may have negative refractive power, and the first and second surfaces of the seventh lens 270 may be concave in the paraxial region.

[0169] At least one inflection point may 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 may be concave in the paraxial region and convex in the portion other than the paraxial region. Furthermore, the second surface of the seventh lens 270 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0170] Each surface of the first lens 210 to the seventh lens 270 has aspherical coefficients listed in Table 4 below. In this example, the first and second surfaces of each of the first lens 210 to the seventh lens 270 are aspherical.

[0171] Table 4

[0172]

[0173]

[0174] The optical imaging system with the above configuration has Figure 4 The aberration characteristics shown are illustrated.

[0175] Figure 5 This is a diagram illustrating a third example of an optical imaging system, and Figure 6 It is shown Figure 5The diagram shows the aberration characteristics of the optical imaging system.

[0176] 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 (not shown), a filter 380, and an image sensor 390.

[0177] The optical properties of each element in the optical imaging system (radius of curvature of each surface of the element, thickness of the element or distance between the element and the next element, refractive index, Abbe number and focal length) are listed in Table 5 below.

[0178] Table 5

[0179]

[0180]

[0181] The third example optical imaging system has a focal length of 6.15697mm for f12, 7.69842mm for f12, 1.87 for fno, 83° for FOV, 5.644mm for IMG HT, 2.755mm for SD5, 4mm for SD6, and 5.14779mm for SD7.

[0182] The definitions of f12, Fno, FOV, IMG HT, SD5, SD6, and SD7 are the same as in the first example.

[0183] 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.

[0184] 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.

[0185] The third lens 330 may have positive refractive power, and the first and second surfaces of the third lens 330 may be convex.

[0186] The fourth lens 340 may have negative 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.

[0187] The fifth lens 350 may have negative refractive power, the first surface of the fifth lens 350 may be convex in the paraxial region, and the second surface of the fifth lens 350 may be concave in the paraxial region.

[0188] Furthermore, at least one inflection point may 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 may be convex in the paraxial region and concave in the portion other than the paraxial region. The second surface of the fifth lens 350 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0189] The sixth lens 360 may have positive refractive power, the first surface of the sixth lens 360 may be convex in the paraxial region, and the second surface of the sixth lens 360 may be concave in the paraxial region.

[0190] At least one inflection point may 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 may be convex in the paraxial region and concave in the portion other than the paraxial region. The second surface of the sixth lens 360 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0191] The seventh lens 370 may have negative refractive power, and the first and second surfaces of the seventh lens 370 may be concave in the paraxial region.

[0192] At least one inflection point may 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 may be concave in the paraxial region and convex in the portion other than the paraxial region. The second surface of the seventh lens 370 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0193] Each surface of the first lens 310 to the seventh lens 370 has aspherical coefficients listed in Table 6 below. In this example, the first and second surfaces of each of the first lens 310 to the seventh lens 370 are aspherical.

[0194] Table 6

[0195]

[0196]

[0197] The optical imaging system with the above configuration has Figure 6 The aberration characteristics shown are illustrated.

[0198] Figure 7 This is a diagram illustrating a fourth example of an optical imaging system, and Figure 8 It is shown Figure 7 The diagram shows the aberration characteristics of the optical imaging system.

[0199] The optical imaging system of the fourth example may include an optical system comprising 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 may also include an aperture (not shown), a filter 480, and an image sensor 490.

[0200] The optical properties of each element in the optical imaging system (radius of curvature of each surface of the element, thickness of the element or distance between the element and the next element, refractive index, Abbe number and focal length) are listed in Table 7 below.

[0201] Table 7

[0202]

[0203]

[0204] The fourth example optical imaging system has a focal length of 6.11088 mm, f12 of 7.88144 mm, Fno of 1.88, FOV of 84°, IMG HT of 5.644 mm, SD5 of 3.195 mm, SD6 of 4.10057 mm, and SD7 of 4.92962 mm.

[0205] The definitions of f12, Fno, FOV, IMG HT, SD5, SD6, and SD7 are the same as in the first example.

[0206] In the fourth example, the first lens 410 may have positive refractive power, the first surface of the first lens 410 may be convex, and the second surface of the first lens 410 may be concave.

[0207] 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.

[0208] The third lens 430 may have positive refractive power, and the first and second surfaces of the third lens 430 may be convex.

[0209] The fourth lens 440 may have negative 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.

[0210] The fifth lens 450 may have negative refractive power, the first surface of the fifth lens 450 may be convex in the paraxial region, and the second surface of the fifth lens 450 may be concave in the paraxial region.

[0211] Furthermore, at least one inflection point may be formed on at least one of the first and second surfaces of the fifth lens 450. For example, the first surface of the fifth lens 450 may be convex in the paraxial region and concave in the portion other than the paraxial region. Similarly, the second surface of the fifth lens 450 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0212] The sixth lens 460 may have positive refractive power, the first surface of the sixth lens 460 may be convex in the paraxial region, and the second surface of the sixth lens 460 may be concave in the paraxial region.

[0213] At least one inflection point may be formed on at least one of the first and second surfaces of the sixth lens 460. For example, the first surface of the sixth lens 460 may be convex in the paraxial region and concave in the portion other than the paraxial region. The second surface of the sixth lens 460 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0214] The seventh lens 470 may have negative refractive power, and the first and second surfaces of the seventh lens 470 may be concave in the paraxial region.

[0215] At least one inflection point may be formed on at least one of the first and second surfaces of the seventh lens 470. For example, the first surface of the seventh lens 470 may be concave in the paraxial region and convex in the portion other than the paraxial region. The second surface of the seventh lens 470 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0216] Each surface of the first lens 410 to the seventh lens 470 has aspherical coefficients listed in Table 8 below. In this example, the first and second surfaces of each of the first lens 410 to the seventh lens 470 are aspherical.

[0217] Table 8

[0218]

[0219] The optical imaging system with the above configuration has Figure 8 The aberration characteristics shown are illustrated.

[0220] Figure 9 This is a diagram illustrating a fifth example of an optical imaging system, and Figure 10 It is shown Figure 9 The diagram shows the aberration characteristics of the optical imaging system.

[0221] The optical imaging system of 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, a fifth lens 550, a sixth lens 560, and a seventh lens 570, and may also include an aperture (not shown), a filter 580, and an image sensor 590.

[0222] The optical properties of each element in the optical imaging system (radius of curvature of each surface of the element, thickness of the element or distance between the element and the next element, refractive index, Abbe number and focal length) are listed in Table 9 below.

[0223] Table 9

[0224]

[0225] The optical imaging system of the fifth example has a focal length of 6.08291 mm, a focal length of 7.93893 mm at f12, a focal length of 1.88, a focal length of 84.3° at FOV, a focal length of 5.644 mm at IMG HT, a focal length of 3.3717 mm at SD5, a focal length of 4.02459 mm at SD6, and a focal length of 5.05356 mm at SD7.

[0226] The definitions of f12, Fno, FOV, IMG HT, SD5, SD6, and SD7 are the same as in the first example.

[0227] In the fifth example, the first lens 510 may have positive refractive power, the first surface of the first lens 510 may be convex, and the second surface of the first lens 510 may be concave.

[0228] The second lens 520 may have negative refractive power, the first surface of the second lens 520 may be convex, and the second surface of the second lens 520 may be concave.

[0229] 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.

[0230] 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.

[0231] The fifth lens 550 may have negative refractive power, the first surface of the fifth lens 550 may be convex in the paraxial region, and the second surface of the fifth lens 550 may be concave in the paraxial region.

[0232] Furthermore, at least one inflection point may 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 may be convex in the paraxial region and concave in the portion other than the paraxial region. The second surface of the fifth lens 550 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0233] The sixth lens 560 may have positive refractive power, the first surface of the sixth lens 560 may be convex in the paraxial region, and the second surface of the sixth lens 560 may be concave in the paraxial region.

[0234] At least one inflection point may 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 may be convex in the paraxial region and concave in the portion other than the paraxial region. The second surface of the sixth lens 560 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0235] The seventh lens 570 may have negative refractive power, and the first and second surfaces of the seventh lens 570 may be concave in the paraxial region.

[0236] At least one inflection point may 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 may be concave in the paraxial region and convex in the portion other than the paraxial region. Furthermore, the second surface of the seventh lens 570 may be concave in the paraxial region and convex in the portion other than the paraxial region.

[0237] Each surface of the first lens 510 to the seventh lens 570 has aspherical coefficients listed in Table 10 below. In this example, the first and second surfaces of each of the first lens 510 to the seventh lens 570 are aspherical.

[0238] Table 10

[0239]

[0240] The optical imaging system with the above configuration has Figure 10 The aberration characteristics shown are illustrated.

[0241] Table 11 below lists the values ​​of conditional expressions 1 to 25 for the optical imaging systems of each of the first to fifth examples.

[0242] Table 11

[0243]

[0244]

[0245] Based on the example above, the optical imaging system has high resolution and reduced size.

[0246] While this disclosure includes specific embodiments, it will be apparent upon understanding the disclosure of this application that various changes in form and detail may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be understood in a descriptive sense only and not for purposes of limitation. The description of features or aspects in each example is considered applicable to similar features or aspects in other examples. Suitable results may be obtained 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 detailed description but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents shall be construed as included in this disclosure.

Claims

1. An optical imaging system, comprising: a first lens having positive refractive power, a convex object side, and a concave image side; a second lens having negative refractive power, a convex object side, and a concave image side; a third lens having positive refractive power; a fourth lens having negative refractive power, a convex object side, and a concave image side; a fifth lens having negative refractive power, a convex object side, and a concave image side; a sixth lens having positive refractive power, a convex object side, and a concave image side; and a seventh lens having negative refractive power and a concave image side, wherein the first lens through the seventh lens are arranged in numerical ascending order along an optical axis from an object side of the optical imaging system toward an image plane, wherein the number of lenses having refractive power in the optical imaging system is seven, wherein 0 < f1 / f < 2 is satisfied, where f1 is a focal length of the first lens and f is a focal length of the optical imaging system, wherein -3.5 ≤ f2 / f ≤ 0 is satisfied, where f2 is a focal length of the second lens, wherein 6.693 ≤ f3 / f ≤ 9.056 is satisfied, where f3 is a focal length of the third lens, and wherein -9 < f4 / f < 0 is satisfied, where f4 is a focal length of the fourth lens. 25 ≤ v1-v2 ≤ 45 and 25 ≤ v1-v4≤ 45 are satisfied, where v1 is an Abbe number of the first lens, v2 is an Abbe number of the second lens, and v4 is an Abbe number of the fourth lens.

2. The optical imaging system of claim 1, wherein, -1 < f1 / f2 < 0 is satisfied.

3. The optical imaging system of claim 1, wherein, 1 ≤ f12 / f ≤ 2 is satisfied, where f12 is a combined focal length of the first lens and the second lens.

4. The optical imaging system of claim 3, wherein, -2 ≤ f2 / f3 ≤ 0 is satisfied.

5. The optical imaging system of claim 3, wherein, 0 < f6 / f < 2 and -2 < f7 / f < 0 are satisfied, where f6 is a focal length of the sixth lens and f7 is a focal length of the seventh lens.

6. The optical imaging system of claim 5, wherein, -5 ≤ f2 / f6 ≤ 0 is satisfied.

7. The optical imaging system of claim 6, wherein, 0 < f2 / f7 < 5 is satisfied.

8. The optical imaging system of claim 6, wherein, D1 / f < 0.3 is satisfied, where D1 is a distance along the optical axis from an image side of the first lens to an object side of the second lens.

9. The optical imaging system of claim 1, wherein, BFL / f < 0.4 is satisfied, where BFL is a distance along the optical axis from an image side of the seventh lens to the image plane.

10. The optical imaging system of claim 9, wherein, TTL / f < 1.4 is satisfied, where TTL is a distance along the optical axis from an object side of the first lens to the image plane.

11. The optical imaging system of claim 10, wherein, 74° < FOV < 90° is satisfied, where FOV is a field of view of the optical imaging system.

12. The optical imaging system of claim 1, wherein, Fno < 2.0 is satisfied, where Fno is an f-number of the optical imaging system.

13. The optical imaging system of claim 1, wherein, the third lens has a convex object side.

14. The optical imaging system of claim 1, wherein, the third lens has a concave image side.

15. The optical imaging system of claim 14, wherein, the seventh lens has a concave object side.

16. The optical imaging system of claim 14, wherein, the first lens through the seventh lens are made of plastic materials.

17. The optical imaging system of claim 1, wherein, the first lens and the second lens are made of plastic materials having different optical characteristics, and the second lens and the third lens are made of plastic materials having different optical characteristics.

18. The optical imaging system of claim 17, wherein, ​ 19. The optical imaging system of claim 18, wherein, The second lens and the fourth lens each have a refractive index greater than 1.

66.

20. The optical imaging system of claim 17, wherein, The object side surface and the image side surface of each of the first lens to the seventh lens are aspherical, the sixth lens has at least one inflection point formed on at least one of the object side surface and the image side surface, and the seventh lens has at least one inflection point formed on at least one of the object side surface and the image side surface.

Images