Optical imaging system

Abstract

An optical imaging system includes a first lens having a refractive power, a second lens having a refractive power and a convex object side, a third lens having a refractive power and a convex object side, a fourth lens having a refractive power, a fifth lens having a refractive power, and a sixth lens having a negative refractive power. The optical imaging system satisfies 100° ≤ FOV and -2.0 < {IMGHT / (f*tan(FOV / 2)) - 1} * 100 < 2.0, where FOV is a field of view of the optical imaging system, IMGHT is half of a diagonal length of an imaging surface, and f is a focal length of the optical imaging system.

Description

[0001] Cross-reference of related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0120733, filed on September 18, 2020, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. Technical Field

[0003] This disclosure relates to an optical imaging system having a wide field of view of 100 degrees or more. Background Technology

[0004] Small cameras can be mounted on wireless terminal devices. For example, a small camera can be mounted on each of the front and rear surfaces of a wireless terminal device. Since such small cameras can be used for various purposes, such as obtaining images of landscapes, indoor portraits, etc., they need to have a performance level similar to that of ordinary cameras. However, due to the limited size of wireless terminal devices, installation space may be limited, making it difficult for small cameras to achieve high performance. Therefore, it is necessary to develop an optical imaging system that can improve the performance of small cameras without increasing their size.

[0005] The above information is presented as background information only to aid in understanding this disclosure. No determination or assertion is made as to whether any of the above content can be used as prior art with respect to this disclosure. Summary of the Invention

[0006] The summary portion of this invention is intended to provide a brief overview of the chosen inventive concepts, which will be further described in the detailed description portion below. This summary portion is not intended to identify key or essential features of the claimed subject matter, nor to help determine the scope of the claimed subject matter.

[0007] In a general sense, the optical imaging system includes: a first lens with refractive power, a second lens with refractive power and a convex object-side surface, a third lens with refractive power and a convex object-side surface, a fourth lens with refractive power, a fifth lens with refractive power, and a sixth lens with negative refractive power, wherein the first to sixth lenses are arranged sequentially from the object side. The optical imaging system satisfies 100° ≤ FOV and -2.0 < {IMGHT / (f tan(FOV / 2))-1} 100 < 2.0, where FOV is the field of view of the optical imaging system, IMGHT is half the diagonal length of the imaging plane, and f is the focal length of the optical imaging system.

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

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

[0010] The fifth lens may have a convex object side or a convex image side.

[0011] The sixth lens may have a convex object-side surface.

[0012] The sixth lens can have a concave image-side surface.

[0013] The optical imaging system can satisfy -1.5 < f3 / f4 < -0.7, where f3 is the focal length of the third lens and f4 is the focal length of the fourth lens.

[0014] The optical imaging system can satisfy 0.6 < |f4 / f6| < 1.8, where f4 is the focal length of the fourth lens and f6 is the focal length of the sixth lens.

[0015] The optical imaging system can satisfy 1.3 < TTL / IMGHT < 1.4, where TTL is the distance from the object side of the first lens to the imaging plane.

[0016] The optical imaging system can satisfy 1.8 < f number < 2.3.

[0017] In another general aspect, the optical imaging system includes a first lens having refractive power, a second lens having refractive power and having a convex object-side surface, a third lens having refractive power and having a convex object-side surface, a fourth lens having refractive power, a fifth lens having refractive power, and a sixth lens having refractive power, wherein the first to sixth lenses are arranged sequentially from the object side, and wherein 100° ≤ FOV, -2.0 < {IMGHT / (f tan(FOV / 2))-1} 100 < 2.0, and TTL / IMGHT < 1.4.

[0018] The sign of the refractive power of the first lens may be different from that of the second lens.

[0019] The sign of the refractive power of the fourth lens may be different from that of the fifth lens.

[0020] The sixth lens can have negative refractive power.

[0021] The optical imaging system can satisfy 1.0 < f1 / f3 < 3.0, where f1 is the focal length of the first lens.

[0022] The optical imaging system can satisfy 0.2 < f3 / f5 < 2.0, where f5 is the focal length of the fifth lens.

[0023] Other features and aspects will become apparent from the following detailed description and accompanying drawings. Attached Figure Description

[0024] Figure 1 This is a diagram illustrating a first example of an optical imaging system.

[0025] Figure 2 Presentation Figure 1 The aberration curves of the optical imaging system are shown.

[0026] Figure 3 This is a diagram illustrating a second example of an optical imaging system.

[0027] Figure 4 Presentation Figure 3 The aberration curves of the optical imaging system are shown.

[0028] Figure 5 This is a diagram illustrating a third example of an optical imaging system.

[0029] Figure 6 Presentation Figure 5 The aberration curves of the optical imaging system are shown.

[0030] Figure 7 This is a diagram illustrating a fourth example of an optical imaging system.

[0031] Figure 8 Presentation Figure 7 The aberration curves of the optical imaging system are shown.

[0032] Figure 9 This is a diagram illustrating the fifth example of an optical imaging system.

[0033] Figure 10 Presentation Figure 9 The aberration curves of the optical imaging system are shown.

[0034] Throughout the accompanying drawings and detailed embodiments, the same reference numerals refer to the same elements. For purposes of clarity, illustration, and convenience, the drawings may not be drawn to scale, and the relative dimensions, scale, and depiction of elements in the drawings may be exaggerated. Detailed Implementation

[0035] The following detailed embodiments are provided to help readers gain a comprehensive understanding of the methods, apparatus, and / or systems described in this application. However, various changes, modifications, and equivalents to the methods, apparatus, and / or systems described in this application will become apparent upon understanding this disclosure. For example, the order of operations described in this application is merely illustrative, and is not limited to the order set forth in this application, except for operations that must occur in a specific order, but can be changed, as will become apparent upon understanding this disclosure. Furthermore, for clarity and conciseness, descriptions of features that are well-known in the art may be omitted.

[0036] The features described in this application may be implemented in different forms and should not be construed as being limited to the examples described in this application. Rather, the examples described in this application are provided merely to illustrate some of the many possible ways in which the methods, apparatuses, and / or systems described in this application will be apparent upon understanding this disclosure.

[0037] It should be noted that in this application, the term "may" is used in relation to examples or implementations, such as with regard to what an example or implementation may include or implement, meaning that there exists at least one example or implementation that includes or implements such features, and that all examples and implementations are not limited thereto.

[0038] 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, the element may be directly "on," directly "connected to," or directly "attached to" the other element, or there may be one or more other elements between the element and the other element. Conversely, when an element is described as being "directly on," "directly connected to," or "directly attached to" another element, there are no other elements between the element and the other element.

[0039] As used in this application, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0040] Although terms such as “first,” “second,” and “third” may be used in this application to describe various components, parts, regions, layers, or portions, these components, parts, regions, layers, or portions are not limited by these terms. Rather, these terms are used only to distinguish one component, part, region, layer, or portion from another. Therefore, without departing from the teachings of the examples described in this application, the first component, first part, first region, first layer, or first portion mentioned in these examples may also be referred to as a second component, second part, second region, second layer, or second portion.

[0041] Spatial relative terms such as “above,” “above,” “below,” and “below” may be used in this application for descriptive convenience to describe the relationship of one element relative to another, as shown in the accompanying drawings. In addition to covering the orientation depicted in the drawings, these spatial relative terms are intended to also cover different orientations of the device in use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “above” another element would be located “below” or “below” that other element. Thus, depending on the spatial orientation of the device, the term “above” covers both orientations of “above” and “below”. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relative terms used in this application should be interpreted accordingly.

[0042] The terminology used in this application is for 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 “comprising,” “including,” and “having” indicate the presence of the stated features, numbers, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, components, elements, and / or combinations thereof.

[0043] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the accompanying drawings may occur. Therefore, the examples described in this application are not limited to the specific shapes shown in the accompanying drawings, but include shape variations that may occur during manufacturing.

[0044] The features of the examples described in this application can be combined in various ways that will become apparent after understanding the disclosure of this application. Furthermore, although the examples described in this application have multiple configurations, other configurations that will become apparent after understanding the disclosure of this application are also possible.

[0045] One aspect of this disclosure is to provide an optical imaging system with a wide field of view.

[0046] In the example, the first lens of the optical imaging system refers to the lens closest to the object (or subject), while the sixth lens refers to the lens closest to the imaging surface (or image sensor). An image sensor with an imaging surface can be positioned on the imaging surface of the optical imaging system. The image sensor converts the image of the object formed by the lenses of the optical imaging system on the effective imaging area of ​​the imaging surface into an electrical signal. In the example, the units for radius of curvature, thickness, TTL (distance along the optical axis from the object-side surface of the first lens to the imaging surface), IMGHT (maximum effective image height of the optical imaging system, equal to half the diagonal length of the effective imaging area of ​​the imaging surface of the image sensor or half the diagonal length of the imaging surface), and focal length are expressed in millimeters (mm). The lens thickness, the gap between lenses, and TTL refer to the distance between lenses along the optical axis. Furthermore, in the description of the lens shape, a configuration with a convex surface indicates that the optical axis region of that surface is convex, and a configuration with a concave surface indicates that the optical axis region of that surface is concave. Therefore, even when describing a lens as having a convex surface, the edges of the lens can be concave. Similarly, even when one surface of a lens is concave, the edges of the lens can be convex.

[0047] The optical imaging system according to this disclosure can achieve a distortion characteristic of less than 2% while realizing a wide field of view. Therefore, the optical imaging system according to this disclosure can reduce image quality degradation caused by spherical aberration and distortion while capturing images at a wide field of view of 100 degrees (100°) or greater. For example, the optical imaging system according to this disclosure can reduce severe distortion at image edges. Therefore, a camera module including the optical imaging system according to this disclosure can omit or reduce software operations for image correction.

[0048] An optical imaging system according to the example may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side. In the optical imaging system, the object sides of the second and third lenses may be convex. The sixth lens may have a predetermined refractive power. For example, the sixth lens may have a negative refractive power. The optical imaging system may have a wide field of view. For example, the field of view (FOV) of the optical imaging system may be 100 degrees or greater. The optical imaging system may have significant distortion aberrations at the maximum height of the imaging plane. For example, the optical imaging system may have distortion aberrations less than +2% or less than -2% at the maximum height of the imaging plane. The following conditional expression illustrates one form of constraint condition used to represent the FOV and distortion characteristics of the optical imaging system.

[0049] -2.0 <{IMGHT / (f tan(FOV / 2))-1} 100 < 2.0

[0050] In the above conditional expression, FOV is the field of view of the optical imaging system, IMGHT is half the diagonal length of the imaging plane, and f is the focal length of the optical imaging system.

[0051] An optical imaging system according to another example may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side. In the optical imaging system, the object sides of the second lens and the third lens may be convex. The optical imaging system may have a wide field of view. For example, the field of view (FOV) of the optical imaging system may be 100 degrees or greater. The optical imaging system may have significant distortion aberrations at the maximum height of the imaging plane. For example, the optical imaging system may have distortion aberrations less than +2% or less than -2% at the maximum height of the imaging plane. The following conditional expression shows another form of constraint for representing the FOV and distortion characteristics of the optical imaging system.

[0052] -2.0<{IMGHT / (f tan(FOV / 2))-1} 100 < 2.0

[0053] TTL / IMGHT < 1.4

[0054] In the above conditional expression, TTL is the distance (mm) from the object surface of the first lens to the imaging surface.

[0055] The detailed configuration of the optical imaging system will be described below.

[0056] An optical imaging system may include six lenses arranged sequentially from the object side along the optical axis. For example, an optical imaging system may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially. The first to sixth lenses may be arranged at predetermined intervals. For example, a predetermined interval may be formed between the image-side surface of the front lens and the object-side surface of the rear lens.

[0057] The first lens may have refractive power. For example, the first lens may have positive or negative refractive power. One surface of the first lens may be concave. For example, the first lens may have a concave object-side surface or a concave image-side surface. The first lens may include an aspherical surface. For example, both surfaces of the first lens may be aspherical. A recurve point may be formed on one surface of the first lens. For example, a recurve point may be formed on the object-side or image-side surface of the first lens. However, the recurve point is not necessarily formed on one surface of the first lens. The first lens may be formed from a material with high light transmittance and excellent processability. For example, a plastic material may be used to manufacture the first lens. However, the material of the first lens is not limited to plastic materials. For example, a glass material may be used to manufacture the first lens. The first lens has a predetermined refractive index. For example, the refractive index of the first lens may be greater than 1.5 and less than 1.6.

[0058] The second lens may have refractive power. For example, the second lens may have positive or negative refractive power. The second lens may have a refractive power with a different sign than that of the first lens. For example, when the first lens has positive refractive power, the second lens may have negative refractive power. Conversely, when the first lens has negative refractive power, the second lens may have positive refractive power. One surface of the second lens may be convex. For example, the second lens may have a convex object-side surface. The second lens may have an aspherical surface. For example, both surfaces of the second lens may be aspherical. The second lens may be formed of a material with high light transmittance and excellent processability. For example, a plastic material may be used to manufacture the second lens. However, the material of the second lens is not limited to plastic materials. For example, a glass material may be used to manufacture the second lens. The second lens may have a predetermined refractive index. For example, the refractive index of the second lens may be greater than 1.5 and less than 1.7.

[0059] The third lens may have refractive power. For example, the third lens may have positive or negative refractive power. One surface of the third lens may be convex. For example, the third lens may have a convex object-side surface. The third lens may have an aspherical surface. For example, two surfaces of the third lens may be aspherical. The third lens may be formed from a material with high light transmittance and excellent machinability. For example, a plastic material can be used to manufacture the third lens. However, the material of the third lens is not limited to plastic materials. For example, a glass material can be used to manufacture the third lens. The third lens may have a predetermined refractive index. For example, the refractive index of the third lens may be greater than 1.5 and less than 1.7.

[0060] The fourth lens may have refractive power. For example, the fourth lens may have positive or negative refractive power. One surface of the fourth lens may be concave. For example, the fourth lens may have a concave object-side surface. The fourth lens may have an aspherical surface. For example, both surfaces of the fourth lens may be aspherical. The fourth lens may be manufactured using materials with high light transmittance and excellent machinability. For example, a plastic material may be used to manufacture the fourth lens. However, the material of the fourth lens is not limited to plastic materials. For example, a glass material may be used to manufacture the fourth lens. The fourth lens may have a predetermined refractive index. For example, the refractive index of the fourth lens may be greater than 1.5 and less than 1.7.

[0061] The fifth lens may have refractive power. For example, the fifth lens may have positive or negative refractive power. The fifth lens may have a refractive power with a different sign than that of the fourth lens. For example, when the fourth lens has positive refractive power, the fifth lens may have negative refractive power. Conversely, when the fourth lens has negative refractive power, the fifth lens may have positive refractive power. One surface of the fifth lens may be convex. For example, the fifth lens may have a convex object-side surface or a convex image-side surface. The fifth lens may have an aspherical surface. For example, both surfaces of the fifth lens may be aspherical. A point of inflection may be formed on one surface of the fifth lens. For example, a point of inflection may be formed on both the object-side and image-side surfaces of the fifth lens. The fifth lens may be formed from a material with high light transmittance and excellent processability. For example, a plastic material may be used to manufacture the fifth lens. However, the material of the fifth lens is not limited to plastic. For example, a glass material may be used to manufacture the fifth lens. The fifth lens may have a predetermined refractive index. For example, the refractive index of the fifth lens may be greater than 1.5 and less than 1.6.

[0062] The sixth lens may have refractive power. For example, the sixth lens may have negative refractive power. One surface of the sixth lens may be convex. For example, the sixth lens may have a convex object-side surface. The sixth lens may have an aspherical surface. For example, both surfaces of the sixth lens may be aspherical. A curvature point may be formed on one surface of the sixth lens. For example, a curvature point may be formed on both the object-side and image-side surfaces of the sixth lens. The sixth lens may be formed from a material with high light transmittance and excellent machinability. For example, a plastic material may be used to manufacture the sixth lens. However, the material of the sixth lens is not limited to plastic materials. For example, a glass material may be used to manufacture the sixth lens. The sixth lens may have a predetermined refractive index. For example, the refractive index of the sixth lens may be greater than 1.5 and less than 1.65.

[0063] Each of the first to sixth lenses may have an aspherical surface. For example, at least one surface of the first to sixth lenses may be aspherical. The aspherical surface of each of the first to sixth lenses can be represented by the following Equation 1:

[0064] (Equation 1)

[0065]

[0066] In Equation 1, “c” is the reciprocal of the radius of curvature of the corresponding lens, “k” is the conic constant, “r” is the distance from a point on the aspherical surface of the lens to the optical axis, “A” to “H” and “J” are aspherical constants, and “Z” (or SAG) is the height from a point on the aspherical surface to the vertex of the aspherical surface in the direction of the optical axis.

[0067] The optical imaging system may also include an aperture stop. The aperture stop may be positioned between a first lens and a second lens, or between a second lens and a third lens. The optical imaging system may also include a filter. The filter may be configured to block light of a specific wavelength from passing through the first lens to the sixth lens. For example, the filter may block incident light of infrared wavelengths. The optical imaging system may also include an image sensor. The image sensor is configured to convert optical signals into electrical signals. The image sensor can provide an area (imaging surface) in which light refracted by the lenses can form an image of an object. For example, the surface of the image sensor may form an imaging plane. The image sensor may include a charge-coupled device (CCD), etc.

[0068] An optical imaging system can satisfy one or more of the following conditional expressions.

[0069] 1.0 < f1 / f3 < 3.0

[0070] -1.5 < f3 / f4 < -0.7

[0071] 0.6 <|f4 / f6| < 1.8

[0072] 0.2 < f3 / f5 < 2.0

[0073] 1.3 < TTL / IMGHT < 1.4

[0074] 1.8 < f-number < 2.3

[0075] In this text and in the above conditional expressions, 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, TTL is the distance from the object side of the first lens to the imaging plane, and IMGHT is half the diagonal length of the imaging plane.

[0076] The following description will depict various examples of optical imaging systems.

[0077] In the following text, reference will be made to Figure 1 Describe the optical imaging system according to the first example.

[0078] The optical imaging system 100 may include lenses, each having refractive power. For example, the optical imaging system 100 may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, and a sixth lens 160.

[0079] The first lens 110 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The second lens 120 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 130 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fourth lens 140 may have negative refractive power and may have a concave object-side surface and a convex image-side surface. The fifth lens 150 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fifth lens 150 may have a shape with a curvature point. For example, a curvature point may be formed on the object-side surface and the image-side surface of the fifth lens 150. The sixth lens 160 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The sixth lens 160 may have a shape with a curvature point. For example, a curvature point may be formed on the object-side surface and the image-side surface of the sixth lens 160.

[0080] The optical imaging system 100 may include an aperture stop ST. For example, the aperture stop ST may be disposed between the second lens 120 and the third lens 130. The optical imaging system 100 may include a filter IF. For example, the filter IF may be disposed between the sixth lens 160 and the imaging surface IP. The filter IF can block light of a specific wavelength from incident. For example, the filter IF according to the first example can block infrared light incident on the imaging surface IP.

[0081] Optical imaging system 100 presents as Figure 2 The aberration characteristics are shown in Table 1. The lens characteristics of the optical imaging system 100 are listed in Table 1, and the aspherical characteristics of the optical imaging system 100 are listed in Table 2.

[0082] Table 1

[0083]

[0084] Table 2

[0085]

[0086] In the following text, reference will be made to Figure 3 Describe the optical imaging system according to the second example.

[0087] The optical imaging system 200 may include lenses, each having refractive power. For example, the optical imaging system 200 may include a first lens 210, a second lens 220, a third lens 230, a fourth lens 240, a fifth lens 250, and a sixth lens 260.

[0088] The first lens 210 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The second lens 220 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 230 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fourth lens 240 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. The fifth lens 250 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The fifth lens 250 may have a shape with a curvature point. For example, a curvature point may be formed on the object-side surface and the image-side surface of the fifth lens 250. The sixth lens 260 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The sixth lens 260 may have a shape with a curvature point. For example, a curvature point may be formed on the object-side surface and the image-side surface of the sixth lens 260.

[0089] The optical imaging system 200 may include an aperture stop ST. For example, the aperture stop ST may be disposed between the second lens 220 and the third lens 230. The optical imaging system 200 may include a filter IF. For example, the filter IF may be disposed between the sixth lens 260 and the imaging surface IP. The filter IF can block light of a specific wavelength from incident. For example, the filter IF according to the second example can block infrared light incident on the imaging surface IP.

[0090] Optical imaging system 200 presents as Figure 4 The aberration characteristics are shown in Table 3. The lens characteristics of the optical imaging system 200 are listed in Table 4.

[0091] Table 3

[0092]

[0093] Table 4

[0094]

[0095] In the following text, reference will be made to Figure 5 Describe the optical imaging system according to the third example.

[0096] The optical imaging system 300 may include lenses, each having refractive power. For example, the optical imaging system 300 includes a first lens 310, a second lens 320, a third lens 330, a fourth lens 340, a fifth lens 350, and a sixth lens 360.

[0097] The first lens 310 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The second lens 320 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The third lens 330 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The fourth lens 340 may have negative refractive power and may have a concave object-side surface and a concave image-side surface. The fifth lens 350 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The fifth lens 350 may have a shape with a curvature point. For example, a curvature point may be formed on the object-side surface and the image-side surface of the fifth lens 350. The sixth lens 360 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The sixth lens 360 may have a shape with a curvature point. For example, a curvature point may be formed on the object-side surface and the image-side surface of the sixth lens 360.

[0098] The optical imaging system 300 may include an aperture stop ST. For example, the aperture stop ST may be disposed between the second lens 320 and the third lens 330. The optical imaging system 300 may include a filter IF. For example, the filter IF may be disposed between the sixth lens 360 and the imaging surface IP. The filter IF can block light of a specific wavelength from incident. For example, the filter IF according to the third example can block infrared light incident on the imaging surface IP.

[0099] The optical imaging system 300 presents as Figure 6 The aberration characteristics are shown in Table 5. The lens characteristics of the optical imaging system 300 are listed in Table 6, and the aspherical characteristics of the optical imaging system 300 are listed in Table 6.

[0100] Table 5

[0101]

[0102] Table 6

[0103]

[0104] Reference Figure 7 Describe the optical imaging system according to the fourth example.

[0105] The optical imaging system 400 may include lenses, each having refractive power. For example, the optical imaging system 400 includes a first lens 410, a second lens 420, a third lens 430, a fourth lens 440, a fifth lens 450, and a sixth lens 460.

[0106] The first lens 410 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 420 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The third lens 430 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 440 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The fifth lens 450 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fifth lens 450 may have a shape with a curvature point. For example, a curvature point may be formed on the object-side surface and the image-side surface of the fifth lens 450. The sixth lens 460 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The sixth lens 460 may have a shape with a curvature point. For example, a curvature point may be formed on the object-side surface and the image-side surface of the sixth lens 460.

[0107] The optical imaging system 400 may include an aperture stop ST. For example, the aperture stop ST may be disposed between the first lens 410 and the second lens 420. The optical imaging system 400 may include a filter IF. For example, the filter IF may be disposed between the sixth lens 460 and the imaging surface IP. The filter IF can block light of a specific wavelength from incident. For example, the filter IF according to the fourth example can block infrared light incident on the imaging surface IP.

[0108] Optical imaging system 400 presents as Figure 8 The aberration characteristics are shown in Table 7. The lens characteristics of the optical imaging system 400 are listed in Table 8.

[0109] Table 7

[0110]

[0111] Table 8

[0112]

[0113] Reference Figure 9 Describe the optical imaging system according to the fifth example.

[0114] The optical imaging system 500 may include lenses, each having refractive power. For example, the optical imaging system 500 includes a first lens 510, a second lens 520, a third lens 530, a fourth lens 540, a fifth lens 550, and a sixth lens 560.

[0115] The first lens 510 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The second lens 520 may have positive refractive power and may have a convex object-side surface and a convex image-side surface. The third lens 530 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fourth lens 540 may have positive refractive power and may have a concave object-side surface and a convex image-side surface. The fifth lens 550 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The fifth lens 550 may have a shape with a curvature point. For example, a curvature point may be formed on the object-side surface and the image-side surface of the fifth lens 550. The sixth lens 560 may have negative refractive power and may have a convex object-side surface and a concave image-side surface. The sixth lens 560 may have a shape with a curvature point. For example, a curvature point may be formed on the object-side surface and the image-side surface of the sixth lens 560.

[0116] The optical imaging system 500 may include an aperture stop ST. For example, the aperture stop ST may be disposed between the first lens 510 and the second lens 520. The optical imaging system 500 may include a filter IF. For example, the filter IF may be disposed between the sixth lens 560 and the imaging surface IP. The filter IF can block light of a specific wavelength from incident. For example, the filter IF according to the fifth example can block infrared light incident on the imaging surface IP.

[0117] The optical imaging system 500 presents as Figure 10 The aberration characteristics are shown. The lens characteristics of the optical imaging system 500 are listed in Table 9, and the aspherical characteristics of the optical imaging system 500 are listed in Table 10.

[0118] Table 9

[0119]

[0120] Table 10

[0121]

[0122] The optical characteristic values ​​and conditional expression values ​​of the optical imaging systems according to the first to fifth examples are listed in Tables 11 and 12.

[0123] Table 11

[0124]

[0125] Table 12

[0126]

[0127] As described above, it is possible to realize an optical imaging system with a field of view of 100 degrees or more and an f number of 2.3 or less.

[0128] While specific examples have been shown and described above, it will be apparent upon understanding this disclosure that various changes in form and detail may be made to these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein should be understood in a descriptive sense only and not for limiting purposes. The description of features or aspects in each example should be understood as applicable to similar features or aspects in other examples. Appropriate results may still be achieved if the described techniques are performed in a different order, and / or if 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 limited by the specific embodiments but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents should be understood to be included in this disclosure.

Claims

1. An optical imaging system, including: The first lens has a concave object-side surface or a concave image-side surface. The second lens has a convex object-side surface; The third lens has a convex object-side surface; The fourth lens has refractive power and a concave object-side surface; The fifth lens has refractive power; as well as The sixth lens has negative refractive power and a convex object-side surface and a concave image-side surface. The first lens to the sixth lens are arranged sequentially from the object side. The optical imaging system has a total of six lenses. At least one of the first to sixth lenses includes an aspherical surface. The sign of the refractive power of the first lens is the same as that of the third lens and the fifth lens, and is different from that of the second lens and the fourth lens. Wherein, when the first lens has positive refractive power, the first lens has a concave object-side surface and a convex image-side surface; the second lens has a concave image-side surface; the third lens has a convex image-side surface; and the fifth lens has a convex image-side surface. Specifically, when the first lens has negative refractive power, the first lens has a convex object-side surface and a concave image-side surface; the second lens has a convex image-side surface; the third lens has a concave image-side surface; the fourth lens has a convex image-side surface; and the fifth lens has a convex object-side surface and a concave image-side surface. The fifth lens has a refractive index greater than 1.5 and less than 1.

6. in, 100° ≤ FOV -2.0 < {IMGHT / (f×tan(FOV / 2))-1}×100 < 2.0, 0.2 < f3 / f5 < 2.0, and 1.3 < TTL / IMGHT < 1.4 Wherein, FOV is the field of view of the optical imaging system, IMGHT is half the diagonal length of the imaging surface, f is the focal length of the optical imaging system, f3 is the focal length of the third lens, f5 is the focal length of the fifth lens, and TTL is the distance from the object side of the first lens to the imaging surface.

2. The optical imaging system according to claim 1, wherein, 1.0 < f1 / f3 < 3.0, where f1 is the focal length of the first lens.

3. The optical imaging system according to claim 1, wherein, -1.5 < f3 / f4 < -0.7, where f4 is the focal length of the fourth lens.

4. The optical imaging system according to claim 1, wherein, 1.8 < f number < 2.

3.

5. The optical imaging system according to claim 1, wherein 0.6 < |f4 / f6| < 1.8, where, f4 is the focal length of the fourth lens, and f6 is the focal length of the sixth lens.

Images