Optical image capturing system

Abstract

The optical image capturing system includes a first lens, a second lens, and a third lens disposed in order from an object side. The optical imaging system meets the requirement of 1.2 mmlt; tTLlt; 2.0 mm and 0 lt; f3 / flt; tTL is the distance from the object side surface of the first lens to the imaging surface, f is the focal length of the optical imaging system, and f3 is the focal length of the third lens.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of priority of Korean Patent Application No. 10 - 2021 - 0173555, filed on Dec. 7, 2021 with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. Technical field

[0003] The following description relates to an optical imaging system configured to capture an image of an object, such as a user's eyeball, in a close - up manner. Background art

[0004] An augmented reality (AR) device or a virtual reality (VR) device is configured to provide an augmented reality or virtual reality scene as if the user is actually viewing the same scene. Since it is important to quickly provide an image corresponding to the user's gaze, a camera module is required to quickly and accurately capture the movement of the user's eyeball (e.g., iris) without significantly increasing the weight and size of the device.

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

[0006] The Summary of the Invention section is intended to introduce, in a brief form, a selection of inventive concepts that will be further described in the Detailed Description section below. The Summary of the Invention section is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

[0007] In one general aspect, an optical imaging system includes a first lens, a second lens, and a third lens sequentially disposed from the object side. The optical imaging system satisfies 1.2 mm < TTL < 2.0 mm and 0 < f3 / f < 1.0, where TTL is the distance from the object surface of the first lens to the imaging surface, f is the focal length of the optical imaging system, and f3 is the focal length of the third lens.

[0008] The optical imaging system may satisfy 0 < f1 / f < 1.5, where f1 is the focal length of the first lens.

[0009] The optical imaging system may satisfy - 1.0 < f2 / f < 0, where f2 is the focal length of the second lens.

[0010] The optical imaging system may satisfy |f1 / f2| < 3.0, where f1 is the focal length of the first lens and f2 is the focal length of the second lens.

[0011] The optical imaging system can satisfy -2.0 < f2 / f3 < 0, where f2 is the focal length of the second lens.

[0012] The optical imaging system can satisfy 0.25 < BFL / TTL < 0.5, where BFL is the distance from the image side of the third lens to the imaging surface.

[0013] The optical imaging system can satisfy Bfin / f < 0.35, where Bfin is the back focal length of the optical imaging system when capturing an image of an object set at infinity.

[0014] The optical imaging system can satisfy TTL / f < 1.8.

[0015] The optical imaging system can satisfy D12 / f < 0.25, where D12 is the distance from the image side of the first lens to the object side of the second lens.

[0016] The optical imaging system can satisfy 1 ≤ V1 - V3 < 40, where V1 is the Abbe number of the first lens and V3 is the Abbe number of the third lens.

[0017] The optical imaging system can satisfy 1 ≤ V1 - V2 < 40, where V1 is the Abbe number of the first lens and V2 is the Abbe number of the second lens.

[0018] In another general aspect, the optical imaging system includes a first lens, a second lens, and a third lens sequentially arranged from the object side, where the second lens has a negative refractive power. The optical imaging system satisfies 1.4 < TTL / f < 1.8, where TTL is the distance from the object side of the first lens to the imaging surface, and f is the focal length of the optical imaging system.

[0019] The first lens can have a convex image side.

[0020] The optical imaging system can satisfy 1.0 < f1 / f3 < 2.6, where f1 is the focal length of the first lens and f3 is the focal length of the third lens.

[0021] The optical imaging system can satisfy 0.4 < f3 / f < 0.8, where f3 is the focal length of the third lens.

[0022] The optical imaging system can satisfy 4.0 < D12 / D23 < 6.0, where D12 is the distance from the image side of the first lens to the object side of the second lens, and D23 is the distance from the image side of the second lens to the object side of the third lens.

[0023] According to the appended claims, the drawings, and the following detailed description, other features and aspects will become apparent. Description of the Drawings

[0024] Figure 1 A configuration of an optical imaging system according to a first example is shown.

[0025] Figure 2 Shows Figure 1 Aberration curves of the optical imaging system shown.

[0026] Figure 3 A configuration of an optical imaging system according to a second example is shown.

[0027] Figure 4 Shows Figure 3 Aberration curves of the optical imaging system shown.

[0028] Figure 5 A configuration of an optical imaging system according to a third example is shown.

[0029] Figure 6 Shows Figure 5 Aberration curves of the optical imaging system shown.

[0030] Figure 7 A configuration of an optical imaging system according to a fourth example is shown.

[0031] Figure 8 Shows Figure 7 Aberration curves of the optical imaging system shown.

[0032] Fig. 9 A configuration of an optical imaging system according to a fifth example is shown.

[0033] Fig.10 Shows Fig. 9 Aberration curves of the optical imaging system shown.

[0034] Fig.11 A configuration of an optical imaging system according to a sixth example is shown.

[0035] Fig.12 Shows Fig.11 Aberration curves of the optical imaging system shown.

[0036] Fig.13 A configuration of a camera module according to an example is shown.

[0037] Fig.14 Shown is equipped with Fig.13 Configuration of the glasses with the camera module shown.

[0038] Throughout the drawings and detailed description, the same reference numerals refer to the same elements. For purposes of clarity, illustration, and convenience, the drawings may not be drawn to scale, and the relative sizes, proportions, and depictions of elements in the drawings may be exaggerated. DETAILED DESCRIPTION

[0039] The following specific embodiments are provided to help the reader gain a comprehensive understanding of the methods, devices and / or systems described herein. However, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent to those of ordinary skill in the art. The order of operations described herein is merely an example, and except for operations that must occur in a particular order, it is not limited to the order set forth herein, but may be changed, which will be apparent to those of ordinary skill in the art. In addition, for greater clarity and brevity, descriptions of functions and structures well known to those of ordinary skill in the art may be omitted.

[0040] The features described herein may be implemented in different forms and should not be understood as being limited to the examples described herein. Rather, the examples described herein have been provided so that this disclosure will be thorough and complete and will fully convey the scope of this disclosure to those of ordinary skill in the art.

[0041] It should be noted that in this document, use of the word "may" with respect to an example or implementation (e.g., with respect to what an example or implementation may include or implement) means that there is at least one example or implementation that includes or implements such features, and all examples and implementations are not limited thereto.

[0042] Throughout the specification, when an element such as a layer, a region, or a substrate is described as being “on,” “connected to,” or “coupled to” another element, the element may be directly “on,” “connected to,” or “coupled to” the other element, or one or more other elements may be present between the element and the other element. Conversely, when an element is described as being “directly on,” “directly connected to,” or “directly coupled to” another element, no other elements may be present between the element and the other element.

[0043] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0044] Although terms such as "first", "second" and "third" may be used herein to describe various members, components, regions, layers or portions, these members, components, regions, layers or portions are not limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer or portion from another member, component, region, layer or portion. Therefore, without departing from the teachings of the examples described herein, the first member, first component, first region, first layer or first portion mentioned in these examples may also be referred to as the second member, second component, second region, second layer or second portion.

[0045] Spatially relative terms such as "above", "higher", "below", and "lower" may be used herein for descriptive convenience to describe the relationship of one element relative to another element as shown in the accompanying drawings. In addition to covering the orientations depicted in the accompanying drawings, these spatially relative terms are intended to also cover different orientations of the device in use or operation. For example, if the device in the accompanying drawings is flipped, an element described as being "above" or "higher" relative to another element will be "below" or "lower" relative to the other element. Therefore, depending on the spatial orientation of the device, the term "above" covers both orientations of "above" and "below". The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein should be interpreted accordingly.

[0046] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the articles "a", "an" and "the" are intended to include plural forms as well. The words "include", "comprise" and "have" indicate the presence of the features, numbers, operations, components, elements and / or combinations thereof, but do not exclude the presence or addition of one or more other features, numbers, operations, components, elements and / or combinations thereof.

[0047] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

[0048] The features of the examples described herein can be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have multiple configurations, other configurations that will be apparent after understanding the disclosure of the present application are also feasible.

[0050] In the example, the first lens refers to the lens closest to the object (or subject), and the seventh lens refers to the lens closest to the imaging plane (or image sensor). In an exemplary embodiment, the units of the radius of curvature, thickness, TTL (the distance from the object side of the first lens to the imaging plane), IMG HT (the height of the imaging plane), focal length, and effective radius of the lens are expressed in millimeters (mm).

[0051] The thickness of the lens, the gap between lenses, and TTL refer to the distance of the lenses on the optical axis. In addition, in the description of the lens shape, a configuration in which one face is convex means that the paraxial region of the face is convex, and a configuration in which one face is concave means that the paraxial region of the face is concave. Therefore, even when one surface of the lens is described as convex, the edge of the lens may be concave. Similarly, even when one surface of the lens is described as concave, the edge of the lens may be convex.

[0052] The optical imaging system described herein may be configured to be installed in a portable electronic device. For example, the optical imaging system may be installed in a smart phone, a laptop computer, an augmented reality (AR) device, a virtual reality (VR) device, a portable game console, glasses, an iris recognition device, etc. However, the scope of use and examples of the optical imaging system described herein are not limited to the above-mentioned electronic devices. For example, the optical imaging system may be applied to an electronic device that provides a narrow installation space but requires high-resolution image capture.

[0053] The optical imaging system according to the example may include a plurality of lenses. For example, the optical imaging system may include a first lens, a second lens, and a third lens arranged in sequence from the object side. The optical imaging system may be configured to achieve miniaturization and weight reduction. For example, in the optical imaging system, the distance TTL from the object side of the first lens to the imaging surface may be less than 2.0 mm. The optical imaging system may be configured such that the distance TTL is greater than a predetermined value to achieve high resolution. For example, the optical imaging system may be configured such that the distance TTL is greater than 1.2 mm. The optical imaging system may satisfy a specific conditional expression with respect to the focal length "f" of the optical imaging system and the focal length "f3" of the third lens. For example, the optical imaging system may satisfy the following conditional expression: 0 <f3 / f<1.0。

[0054] The optical imaging system according to the example may include a first lens, a second lens, and a third lens arranged in sequence from the object side. The optical imaging system may include a lens having a predetermined refractive power. For example, the optical imaging system may include a second lens having a negative refractive power. The optical imaging system may satisfy a specific conditional expression with respect to a focal length "f" of the optical imaging system and a distance "TTL" from the object side of the first lens to the imaging surface. For example, the optical imaging system may satisfy the following conditional expression: 1.4 <TTL / f<1.8。

[0055] The optical imaging system described herein may satisfy one or more of the following conditional expressions. For example, the optical imaging system according to various examples may satisfy one or more of the following conditional expressions.

[0056] 0 <f1 / f<1.5

[0057] -1.0 <f2 / f<0

[0058] 0 <f3 / f<1.0

[0059] |f1 / f2|<3.0

[0060] -2.0 <f2 / f3<0

[0061] 0.25 <BFL / TTL<0.5

[0062] Bfin / f<0.35

[0063] TTL / f<1.8

[0064] D12 / f<0.25

[0065] 1≤V1-V3<40

[0066] 1≤V1-V2<40

[0067] In the above conditional expressions, "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, "TTL" is the distance from the object side surface of the first lens to the imaging plane, "BFL" is the distance from the image side surface of the third lens to the imaging plane, "Bfin" is the back focal length of the optical imaging system when imaging an image of an object set at infinity, "D12" is the distance from the image side surface of the first lens to the object side surface of the second lens, V1 is the Abbe number of the first lens, V2 is the Abbe number of the second lens, and V3 is the Abbe number of the third lens.

[0068] The optical imaging system may satisfy some of the above conditional expressions in a more limited form as shown below.

[0069] 0.8 <f1 / f<1.2

[0070] -0.8 <f2 / f<-0.3

[0071] 0.4 <f3 / f<0.8

[0072] -1.2 <f2 / f3<-0.8

[0073] 1.4 <TTL / f<1.8

[0074] 0.12 <D12 / f<0.24

[0075] The optical imaging system according to the example may satisfy one or more of the following conditional expressions. For example, the optical imaging system may satisfy one or more of the following conditional expressions while satisfying one or more of the above conditional expressions.

[0076] 1.0 <f1 / f3<2.6

[0077] 4.0 <D12 / D23<6.0

[0078] 0<(R1+R2) / (R1-R2)<0.4

[0079] -5.0<(R5+R6) / (R5-R6)<-1.0

[0080] 0.1<(R1+R2) / T1<2.4

[0081] 2.0<(R5+R6) / T3<3.6

[0082] In the above conditional expressions, "D23" is the distance from the image side surface of the second lens to the object side surface of the third lens, "R1" is the curvature radius of the object side surface of the first lens, "R2" is the curvature radius of the image side surface of the first lens, "R5" is the curvature radius of the object side surface of the third lens, "R6" is the curvature radius of the image side surface of the third lens, "T1" is the thickness of the first lens, and "T3" is the thickness of the third lens.

[0083] The optical imaging system according to various examples may include a lens with specific characteristics. For example, the optical imaging system may include a specific lens with a high refractive index and a high Abbe number. As a detailed example, the optical imaging system may include one or more specific lenses with a refractive index of 1.6 or greater and an Abbe number of 50 or greater. The specific lens may be configured to block light of a specific wavelength. For example, the specific lens may be configured to block visible light. As a detailed example, the specific lens may be configured to transmit only light with a wavelength of 780nm. Since the optical imaging system including the specific lens can omit the configuration of the filter, this may be advantageous for the miniaturization and weight reduction of the camera module. The specific lens may have an opaque color. For example, the specific lens may have a black color. However, the color of the specific lens is not limited to black.

[0084] If desired, the optical imaging system described herein may include one or more lenses having the following characteristics. As an example, the optical imaging system may include one of the first to third lenses having the following characteristics. As another example, the optical imaging system may include two or more lenses among the first to third lenses having the following characteristics. However, the optical imaging system according to the above examples does not necessarily include lenses having the following characteristics. Hereinafter, the characteristics of the first to third lenses will be described.

[0085] The first lens may have a refractive power. For example, the first lens may have a positive refractive power. The first lens may have a convex surface. For example, the first lens may have a convex image side surface. The first lens may have a spherical surface or an aspherical surface. As an example, both surfaces of the first lens may be aspherical. The first lens may be formed of a material having a high light transmittance and improved processability. For example, the first lens may be formed of a plastic material or a glass material. The first lens may be configured to have a predetermined refractive index. As an example, the refractive index of the first lens may be greater than 1.5. As a detailed example, the refractive index of the first lens may be greater than 1.5 and less than 1.7. The first lens may have a predetermined Abbe number. As an example, the Abbe number of the first lens may be 40 or more. As a detailed example, the Abbe number of the first lens may be greater than 50 and less than 60.

[0086] The second lens may have a refractive power. For example, the second lens may have a negative refractive power. The second lens may have a concave surface. As an example, the second lens may have a concave object side surface. As another example, the second lens may have a concave image side surface. The second lens includes a spherical surface or an aspherical surface. For example, both surfaces of the second lens may be aspherical. The second lens may be formed of a material having high light transmittance and excellent processability. For example, the second lens may be formed of a plastic material or a glass material. The second lens may be configured to have a predetermined refractive index. As an example, the refractive index of the second lens may be greater than 1.6. The second lens may have a predetermined Abbe number. For example, the Abbe number of the second lens may be 20 or greater. As a detailed example, the Abbe number of the second lens may be greater than 20 and less than 60.

[0087] The third lens has a refractive power. For example, the third lens may have a positive refractive power. The third lens may have a spherical surface or an aspherical surface. As an example, both surfaces of the third lens may be aspherical. The third lens may have an inflection point. For example, an inflection point may be formed on at least one of the object side surface and the image side surface of the third lens. The third lens may be formed of a material having a high light transmittance and improved processability. For example, the third lens may be formed of a plastic material or a glass material. The third lens may be configured to have a predetermined refractive index. For example, the refractive index of the third lens may be greater than 1.6. As a detailed example, the refractive index of the third lens may be greater than 1.6 and less than 1.7. The third lens may have a predetermined Abbe number. For example, the Abbe number of the third lens may be 20 or more. As a detailed example, the Abbe number of the third lens may be greater than 20 and less than 60.

[0088] The plurality of lenses may be formed of a material having a refractive index different from that of air. For example, the plurality of lenses may be formed of a plastic material or a glass material. At least one of the plurality of lenses may have an aspherical surface. The aspherical surface of the lens may be represented by the following equation 1.

[0089] Equation 1:

[0090]

[0091] In Equation 1, "c" is the inverse of the radius of curvature of the corresponding lens, "k" is the cone constant, "r" is the distance from a point on the aspherical surface of the lens to the optical axis, "A to J" are aspherical constants, and "Z" (or "SAG") is the height from a point on the aspherical surface of the lens to the vertex of the aspherical surface in the optical axis direction.

[0092] The optical imaging systems described herein may include filters and apertures.

[0093] The filter may be disposed between the third lens and the imaging plane. However, the position of the filter is not limited to the position between the third lens and the imaging plane. The filter may be configured to block light of some wavelengths. For example, the filter may be configured to block infrared rays. The diaphragm may be disposed on the object side of the first lens, or between one lens and another lens. If desired, the diaphragm may be omitted.

[0094] Next, a detailed example of the optical imaging system will be described with reference to the accompanying drawings.

[0095] Reference Figure 1 An optical imaging system according to a first example is described.

[0096] The optical imaging system 100 may include a first lens 110, a second lens 120, and a third lens 130 arranged in sequence from the object side. The first lens 110 may have positive refractive power and may have a convex object side surface and a convex image side surface. The second lens 120 may have negative refractive power and may have a concave 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 concave image side surface. An inflection point may be formed on the object side surface and the image side surface of the third lens 130.

[0097] The optical imaging system 100 may further include an optical filter IF. The optical filter IF may be disposed between the third lens 130 and the imaging plane IP. The imaging plane IP may be formed on a surface of the image sensor IS or inside the image sensor IS.

[0098] Tables 1 and 2 show lens characteristics and aspheric values ​​of the optical imaging system 100, and Figure 2 Aberration curves of the optical imaging system 100 are shown.

[0099] Table 1

[0100] Face number Configuration Radius of curvature Thickness / distance Refractive Index Abbe number S1 First lens 1.1311 0.2230 1.540 56.0 S2 -0.6271 0.1274 S3 Second lens -0.3044 0.1937 1.652 20.4 S4 0.6536 0.0300 S5 The third lens 0.1752 0.2000 1.652 20.4 S6 0.5356 0.1468 S7 Optical Filters infinity 0.4000 1.517 64.2 S8 infinity 0.1141 S9 Imaging surface infinity 0.0000

[0101] Table 2

[0102]

[0103]

[0104] Reference Figure 3 An optical imaging system according to a second example is described.

[0105] The optical imaging system 200 may include a first lens 210, a second lens 220, and a third lens 230 arranged in sequence from the object side. The first lens 210 may have a positive refractive power and may have a convex object side surface and a convex image side surface. The second lens 220 may have a negative refractive power and may have a concave object side surface and a convex image side surface. The third lens 230 may have a positive refractive power and may have a convex object side surface and a concave image side surface. An inflection point may be formed on the object side surface and the image side surface of the third lens 230.

[0106] The optical imaging system 200 further includes an optical filter IF. The optical filter IF may be disposed between the third lens 230 and the imaging plane IP. The imaging plane IP may be formed on a surface of the image sensor IS or inside the image sensor IS.

[0107] Tables 3 and 4 show lens characteristics and aspheric values ​​of the optical imaging system 200, and Figure 4 Aberration curves of the optical imaging system 200 are shown.

[0108] Table 3

[0109] Face number Configuration Radius of curvature Thickness / distance Refractive Index Abbe number S1 First lens 1.1466 0.2601 1.540 56.0 S2 -1.0033 0.2266 S3 Second lens -0.3750 0.2200 1.652 20.4 S4 -2.2027 0.0510 S5 The third lens 0.2864 0.2769 1.652 20.4 S6 0.4636 0.2036 S7 Optical Filters infinity 0.2100 1.517 64.2 S8 infinity 0.1630 S9 Imaging surface infinity 0.0110

[0110] Table 4

[0111]

[0112]

[0113] Reference Figure 5 An optical imaging system according to a third example is described.

[0114] The optical imaging system 300 may include a first lens 310, a second lens 320, and a third lens 330 arranged in sequence from the object side. The first lens 310 may have positive refractive power and may have a convex object side surface and a convex image side surface. The second lens 320 may have negative refractive power and may have a concave object side surface and a convex image side surface. The third lens 330 may have positive refractive power and may have a convex object side surface and a concave image side surface. An inflection point may be formed on the object side surface and the image side surface of the third lens 330.

[0115] The optical imaging system 300 further includes an optical filter IF. The optical filter IF may be disposed between the third lens 330 and the imaging plane IP. The imaging plane IP may be formed on a surface of the image sensor IS or inside the image sensor IS.

[0116] Tables 5 and 6 show lens characteristics and aspheric values ​​of the optical imaging system 300, and Figure 6 Aberration curves of the optical imaging system 300 are shown.

[0117] Table 5

[0118] Face number Configuration Radius of curvature Thickness / distance Refractive Index Abbe number S1 First lens 1.1468 0.2604 1.540 56.0 S2 -0.9711 0.2122 S3 Second lens -0.3756 0.2200 1.652 20.4 S4 -2.4727 0.0404 S5 The third lens 0.2858 0.2515 1.652 20.4 S6 0.4793 0.1656 S7 Optical Filters infinity 0.0000 1.517 64.2 S8 infinity 0.3864 S9 Imaging surface infinity 0.0120

[0119] Table 6

[0120]

[0121]

[0122] Reference Figure 7 An optical imaging system according to a fourth example is described.

[0123] The optical imaging system 400 may include a first lens 410, a second lens 420, and a third lens 430 arranged in sequence from the object side. The first lens 410 may have a positive refractive power and may have a convex object side surface and a convex image side surface. The second lens 420 may have a negative refractive power and may have a concave object side surface and a concave image side surface. The third lens 430 may have a positive refractive power and may have a convex object side surface and a concave image side surface. An inflection point may be formed on the object side surface and the image side surface of the third lens 430. The imaging plane IP may be formed on the surface of the image sensor IS or inside the image sensor IS.

[0124] In the optical imaging system 400, the first lens 410 may be configured to have specific characteristics. For example, the first lens 410 may be formed of a material having a high refractive index and a high Abbe number. As a detailed example, the first lens 410 may be formed of a material having a refractive index of 1.6 or greater and an Abbe number of 50 or greater. The optical imaging system 400 may include a lens configured to block light of a specific wavelength. For example, in the optical imaging system 400, the first lens 410 may be configured to block visible light and only transmit light having an infrared wavelength. Therefore, in the optical imaging system 400, the filter configuration may be omitted to achieve miniaturization and weight reduction of the camera module.

[0125] Tables 7 and 8 show lens characteristics and aspheric values ​​of the optical imaging system 400, and Figure 8 Aberration curves of the optical imaging system 400 are shown.

[0126] Table 7

[0127]

[0128]

[0129] Table 8

[0130] Face number S1 S2 S3 S4 S5 S6 k 1.0296.E+00 -9.9000.E+01 -3.1857.E+00 9.5578.E-01 -8.7782.E+00 -3.0651.E+00 A 5.2569.E-02 -2.8265.E+01 -6.2608.E+00 -1.1075.E+02 -4.2406.E+00 -2.9498.E+00 B -1.1253.E+03 1.4732.E+03 -1.0053.E+01 7.8496.E+03 -1.2151.E+02 -4.6495.E+01 C 2.2906.E+05 -8.2416.E+04 3.8504.E+03 -5.1230.E+05 3.4492.E+03 9.5899.E+02 D -2.9224.E+07 3.3762.E+06 -2.6215.E+05 2.5718.E+07 -4.4983.E+04 -8.7502.E+03 E 2.4324.E+09 -9.4783.E+07 1.5634.E+07 -9.4851.E+08 3.6175.E+05 4.8420.E+04 F -1.3788.E+11 1.7840.E+09 -6.1841.E+08 2.5630.E+10 -1.9229.E+06 -1.7683.E+05 G 5.4699.E+12 -2.2543.E+10 1.6996.E+10 -5.0977.E+11 6.9438.E+06 4.4265.E+05 H -1.5424.E+14 1.9476.E+11 -3.3199.E+11 7.4783.E+12 -1.7328.E+07 -7.7512.E+05 J 3.1048.E+15 -1.1667.E+12 4.5357.E+12 -8.0560.E+13 3.0135.E+07 9.5660.E+05

[0131] Reference Fig. 9 An optical imaging system according to a fifth example is described.

[0132] The optical imaging system 500 may include a first lens 510, a second lens 520, and a third lens 530 arranged in sequence from the object side. The first lens 510 may have a positive refractive power and may have a convex object side surface and a convex image side surface. The second lens 520 may have a negative refractive power and may have a concave object side surface and a concave image side surface. The third lens 530 may have a positive refractive power and may have a convex object side surface and a concave image side surface. An inflection point may be formed on the object side surface and the image side surface of the third lens 530. The imaging plane IP may be formed on the surface of the image sensor IS or inside the image sensor IS.

[0133] In the optical imaging system 500, the second lens 520 may be configured to have specific characteristics. For example, the second lens 520 may be formed of a material having a high refractive index and a high Abbe number. As a detailed example, the second lens 520 may be formed of a material having a refractive index of 1.6 or greater and an Abbe number of 50 or greater. The optical imaging system 500 may include a lens configured to block light of a specific wavelength. For example, in the optical imaging system 500, the second lens 520 may be configured to block visible light and only transmit light having an infrared wavelength. Therefore, in the optical imaging system 500, the filter configuration may be omitted to achieve miniaturization and weight reduction of the camera module.

[0134] Tables 9 and 10 show lens characteristics and aspheric values ​​of the optical imaging system 500, and Fig.10 Aberration curves of the optical imaging system 500 are shown.

[0135] Table 9

[0136] Face number Configuration Radius of curvature Thickness / distance Refractive Index Abbe number S1 First lens 0.9262 0.2258 1.540 56.0 S2 -0.8829 0.1683 S3 Second lens -0.3521 0.1927 1.642 55.0 S4 1.0416 0.0308 S5 The third lens 0.2003 0.2603 1.652 20.4 S6 0.4984 0.1303 S7 infinity 0.2169 S8 infinity 0.0750 S9 Imaging surface infinity 0.0000

[0137] Table 10

[0138] Face number S1 S2 S3 S4 S5 S6 k 2.6336.E+00 -9.9000.E+01 -2.8030.E+00 1.8606.E+00 -8.6641.E+00 -3.6979.E+00 A 3.8478.E-01 -2.1501.E+01 -1.1151.E+01 -1.3709.E+02 -3.6144.E+00 -2.9220.E-01 B -1.0301.E+03 9.3047.E+02 5.1514.E+02 1.1015.E+04 -1.2892.E+02 -1.1838.E+02 C 1.6618.E+05 -4.9490.E+04 -5.0340.E+04 -8.1214.E+05 3.7710.E+03 2.1145.E+03 D -1.7448.E+07 1.9884.E+06 2.9611.E+06 4.5690.E+07 -5.4607.E+04 -2.0801.E+04 E 1.2497.E+09 -5.4713.E+07 -1.0507.E+08 -1.8785.E+09 4.9647.E+05 1.3097.E+05 F -6.3618.E+10 9.9975.E+08 2.2891.E+09 5.6316.E+10 -2.9979.E+06 -5.5704.E+05 G 2.3508.E+12 -1.2144.E+10 -2.5637.E+10 -1.2373.E+12 1.2266.E+07 1.6441.E+06 H -6.3541.E+13 1.0019.E+11 -3.1159.E+10 1.9974.E+13 -3.4510.E+07 -3.4172.E+06 J 1.2525.E+15 -5.7083.E+11 5.4827.E+12 -2.3601.E+14 6.7358.E+07 5.0242.E+06

[0139] Reference Fig.11 An optical imaging system according to a sixth example is described.

[0140] The optical imaging system 600 may include a first lens 610, a second lens 620, and a third lens 630 arranged in sequence from the object side. The first lens 610 may have a positive refractive power and may have a convex object side surface and a convex image side surface. The second lens 620 may have a negative refractive power and may have a concave object side surface and a concave image side surface. The third lens 630 may have a positive refractive power and may have a convex object side surface and a concave image side surface. An inflection point may be formed on the object side surface and the image side surface of the third lens 630. The imaging plane IP may be formed on the surface of the image sensor IS or inside the image sensor IS.

[0141] In the optical imaging system 600, the third lens 630 may be configured to have specific characteristics. For example, the third lens 630 may be formed of a material having a high refractive index and a high Abbe number. As a specific example, the third lens 630 may be formed of a material having a refractive index of 1.6 or greater and an Abbe number of 50 or greater. The optical imaging system 600 may include a lens configured to block light of a specific wavelength. For example, in the optical imaging system 600, the third lens 630 may be configured to block visible light and only transmit light having an infrared wavelength. Therefore, in the optical imaging system 600, the filter configuration may be omitted to achieve miniaturization and weight reduction of the camera module.

[0142] Tables 11 and 12 show lens characteristics and aspheric values ​​of the optical imaging system 600, and Fig.12 Aberration curves of the optical imaging system 600 are shown.

[0143] Table 11

[0144] Face number Configuration Radius of curvature Thickness / distance Refractive Index Abbe number S1 First lens 1.0795 0.2251 1.540 56.0 S2 -0.6957 0.1644 S3 Second lens -0.3671 0.2256 1.652 20.4 S4 0.8597 0.0338 S5 The third lens 0.2036 0.3110 1.642 55.0 S6 0.5167 0.1447 S7 infinity 0.0000 S8 infinity 0.2260 S9 Imaging surface infinity 0.0000

[0145] Table 12

[0146] Face number S1 S2 S3 S4 S5 S6 k 3.6601.E-01 -9.9000.E+01 -2.9884.E+00 2.9608.E-01 -8.0180.E+00 -4.2716.E+00 A 2.0594.E+00 -3.8411.E+01 -1.0484.E+01 -1.2024.E+02 -2.7204.E+00 9.6544.E-01 B -1.8463.E+03 2.5816.E+03 4.0213.E+02 8.9994.E+03 -9.1699.E+01 -9.2556.E+01 C 3.5849.E+05 -1.6984.E+05 -2.8543.E+04 -6.3020.E+05 2.4115.E+03 1.3218.E+03 D -4.4276.E+07 7.9447.E+06 1.2878.E+06 3.4136.E+07 -3.1037.E+04 -1.0799.E+04 E 3.6356.E+09 -2.5027.E+08 -2.6193.E+07 -1.3622.E+09 2.5039.E+05 5.7010.E+04 F -2.0623.E+11 5.2557.E+09 -2.3058.E+08 3.9850.E+10 -1.3422.E+06 -2.0413.E+05 G 8.2717.E+12 -7.4236.E+10 3.0575.E+10 -8.5742.E+11 4.8793.E+06 5.0826.E+05 H -2.3749.E+14 7.1903.E+11 -9.2591.E+11 1.3587.E+13 -1.2206.E+07 -8.9227.E+05 J 4.8899.E+15 -4.8419.E+12 1.5770.E+13 -1.5782.E+14 2.1193.E+07 1.1090.E+06

[0147] Tables 13 to 14 show optical characteristic values ​​and conditional expression values ​​of the optical imaging systems according to the first to sixth examples.

[0148] Table 13

[0149]

[0150]

[0151] Table 14

[0152]

[0153] In the following, reference will be made to Fig.13 and Fig.14 A camera module and a portable device having the camera module mounted thereon according to examples are described.

[0154] The camera module 10 may include a lens barrel 12 and a substrate 14. However, the configuration of the camera module 10 is not limited to the above configuration. For example, the camera module 10 may further include a cover glass CG. The cover glass CG may prevent the introduction of foreign matter and may reduce the transmission of external impact vibration to the inside of the camera module 10.

[0155] The lens barrel 12 may be configured to accommodate a lens. For example, one of the optical imaging systems 100, 200, 300, 400, 500, and 600 according to the first to sixth examples may be accommodated in the lens barrel 12. The lens barrel 12 may be configured to facilitate weight reduction of the camera module 10. For example, the lens barrel 12 may be formed of a plastic material. The lens barrel 12 may be configured to facilitate miniaturization of the camera module 10. For example, the lens barrel 12 may be configured to have a minimum size and a minimum volume that allow the optical imaging system 100, 200, 300, 400, 500, and 600 to be accommodated therein.

[0156] The substrate 14 may be configured to be coupled to the lens barrel 12. For example, the substrate 14 may be attached to one side of the lens barrel 12 by an adhesive. However, the coupling between the substrate 14 and the lens barrel 12 is not limited to the bonding method. The electronic components required to drive the camera module 10 may be mounted on the substrate 14 or embedded in the substrate 14. For example, the image sensor IS may be mounted on the substrate 14. The image sensor IS may be formed with a minimum size or minimum shape to allow miniaturization of the camera module 10. For example, the image sensor IS may be formed to have a shape (e.g., a square) in which the image captured by the optical imaging system 100, 200, 300, 400, 500, and 600 may be inscribed. However, the shape of the image sensor IS is not limited to a square.

[0157] The camera module 10 of the above configuration may be mounted on a portable device. For example, the camera module 10 may be mounted on glasses 30 manufactured to realize augmented reality (AR) or virtual reality (VR), such as Fig.14 As shown. The camera module 10 may be configured to capture an image of the wearer's eyeball (in detail, iris). For example, the camera module 10 may be disposed on the nose pad 34 of the eyeglass frame 32 to capture an image of the wearer's iris and movement of the iris in real time.

[0158] As described above, according to various examples, weight reduction and miniaturization can be achieved. Therefore, a camera module that can be mounted on glasses having a general shape as well as augmented reality (VR) and virtual reality (VR) devices can be manufactured.

[0159] Although specific examples have been shown and described above, it will be apparent after gaining an understanding of the present disclosure that various changes in form and detail may be made to these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are understood in a descriptive sense only and not for limiting purposes. The description of the features or aspects in each example should be considered to be applicable to similar features or aspects in other examples. If the described techniques are performed in a different order, and / or if the components in the described systems, architectures, devices, or circuits are replaced or supplemented in different ways and / or by other components or their equivalents, appropriate results can still be achieved. Therefore, the scope of the present disclosure is not limited by specific embodiments, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents should be understood to be included in the present disclosure.

Claims

1. An optical imaging system, comprising: A first lens with positive refractive power, a second lens with negative refractive power, and a third lens with positive refractive power, which are sequentially arranged from the object side; Wherein: 1.2mm < TTL < 2.0mm, -0.8 < f2 / f < -0.3, and 4.0 < D12 / D23 < 6.0, where TTL is the distance from the object side surface of the first lens to the imaging surface, f is the focal length of the optical imaging system, f2 is the focal length of the second lens, D12 is the distance from the image side surface of the first lens to the object side surface of the second lens, and D23 is the distance from the image side surface of the second lens to the object side surface of the third lens, and Wherein, the optical imaging system has a total of three lenses.

2. The optical imaging system according to claim 1, wherein: The first lens has a convex object side surface.

3. The optical imaging system according to claim 1, wherein: The first lens has a convex image side surface.

4. The optical imaging system according to claim 1, wherein: The second lens has a concave object side surface.

5. The optical imaging system according to claim 1, wherein: The second lens has a concave image side surface.

6. The optical imaging system according to claim 1, wherein: The third lens has a convex object side surface.

7. The optical imaging system according to claim 1, wherein: The third lens has a concave image side surface.

8. An optical imaging system, comprising: A first lens with positive refractive power, a second lens with negative refractive power, and a third lens with positive refractive power, which are sequentially arranged from the object side; Wherein: 1.4 < TTL / f < 1.8, -0.8 < f2 / f < -0.3 and 4.0 < D12 / D23 < 6.0, where TTL is the distance from the object side surface of the first lens to the imaging surface, f is the focal length of the optical imaging system, f2 is the focal length of the second lens, D12 is the distance from the image side surface of the first lens to the object side surface of the second lens, and D23 is the distance from the image side surface of the second lens to the object side surface of the third lens, and Wherein, the optical imaging system has a total of three lenses.

9. The optical imaging system according to claim 8, wherein: The first lens has a convex object side surface.

10. The optical imaging system according to claim 8, wherein: The first lens has a convex image side surface.

11. The optical imaging system according to claim 8, wherein: The second lens has a concave object side surface.

12. The optical imaging system according to claim 8, wherein: The second lens has a concave image side surface.

13. The optical imaging system according to claim 8, wherein: The third lens has a convex object side surface.

14. The optical imaging system according to claim 8, wherein: The third lens has a concave image side surface.

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