Optical system and camera module including the same

Abstract

An optical system disclosed in an embodiment includes first to ninth lenses arranged in a direction from an object side to a sensor side along an optical axis, in which the first to third lenses have different refractive powers on the optical axis, the first to third lenses have a meniscus shape protruding toward the object side on the optical axis, and the first to ninth lenses are arranged in a direction from the object side to the sensor side along the optical axis. Object-side surfaces of the respective eighth and ninth lenses have a convex shape on the optical axis, and may satisfy the following mathematical expressions: 0.5 lt; sigma CT / sigma CGlt; 3 and 0 lt; cTMaxt / CGMaxt, and CTMaxt / Sigma CT is the sum of the center thickness of the first lens to the ninth lens, Sigma CG is the sum of the gaps between the first lens to the ninth lens along the optical axis, CTMax is the maximum value of the center thickness of the lens, and CGMax is the maximum value of the gap along the optical axis.

Description

Technical Field

[0001] Embodiments relate to an optical system for improving optical performance and a camera module including the optical system. Background Art

[0002] Camera modules capture objects and store them as images or videos, and are installed in various applications. In particular, camera modules are manufactured in very small sizes and are applied not only to portable devices such as smartphones, tablets, and notebook computers, but also to drones and vehicles to provide various functions.

[0003] For example, the optical system of the camera module may include an imaging lens for forming an image and an image sensor for converting the formed image into an electrical signal. In this case, the camera module may perform an auto focus (AF) function of aligning the focal length of the lens by automatically adjusting the distance between the image sensor and the imaging lens, and may perform a zoom function of zooming in or out by increasing or decreasing the magnification of a remote object through a zoom lens. In addition, the camera module employs an image stabilization (IS) technology to correct or prevent image instability caused by an unstable fixture or camera movement caused by a user's action.

[0004] The most important element of a camera module for obtaining an image is an imaging lens that forms an image. Recently, interest in high performance such as high image quality and high resolution has been increasing, and research on an optical system including a plurality of lenses is being conducted to achieve such high performance. For example, research is being conducted to achieve a high performance optical system using a plurality of imaging lenses having positive (+) and / or negative (-) refractive power.

[0005] However, when multiple lenses are included, there is a problem in that it is difficult to obtain excellent optical characteristics and aberration characteristics. In addition, when multiple lenses are included, the thickness, distance, size, etc. of the multiple lenses may cause the total length, height, etc. to increase, thereby increasing the total size of the module including the multiple lenses.

[0006] In addition, in order to achieve high resolution and high definition, the size of image sensors is increasing. However, when the size of image sensors increases, the TTL (Total Track Length) of an optical system including multiple lenses also increases, resulting in an increase in the thickness of a camera and a mobile terminal including the optical system. Therefore, a new optical system that can solve the above problems is needed. Summary of the invention

[0007]

Technical issues

[0008] Embodiments of the present invention provide an optical system with improved optical characteristics. Embodiments provide an optical system having excellent optical performance in the central and peripheral portions of the field of view. Embodiments provide an optical system that can have a thin structure.

[0009]

Technical Solution

[0010] The optical system according to an embodiment of the present invention includes a first lens to a ninth lens, which are arranged along the optical axis in the direction from the object side to the sensor side. Among them, the first lens and the third lens have different refractive powers on the optical axis, the first lens to the third lens have a meniscus shape convex toward the object side on the optical axis, the object-side surface of each of the eighth lens and the ninth lens has a convex shape on the optical axis, and the following mathematical formula (equation) can be satisfied: 0.5 < ∑CT / ∑CG < 3 and 0 < CT_Max / CG_Max < 2 (∑CT is the sum of the central thicknesses of the first lens to the ninth lens, ∑CG is the sum of the optical axis distances between the first lens to the ninth lens, CT_Max is the maximum value of the central thickness of each lens, and CG_Max is the maximum value of the optical axis distance).

[0011] According to an embodiment of the present invention, the object-side surface of the eighth lens has a first critical point, and the sensor-side surface of the eighth lens has a second critical point, and the second critical point can be arranged more outside relative to the optical axis than the first critical point.

[0012] According to an embodiment of the present invention, the first critical point is arranged within the range of 32% to 52% of the distance from the optical axis of the object-side surface of the eighth lens to the end of the effective region, and the second critical point can be arranged within the range of 14% to 34% of the distance from the optical axis of the sensor-side surface of the ninth lens to the end of the effective region.

[0013] According to an embodiment of the present invention, the maximum angle of the tangent passing through the sensor-side surface of the eighth lens can be greater than the maximum angle of the tangent passing through the sensor-side surface of the ninth lens.

[0014] According to an embodiment of the present invention, each of the eighth lens and the ninth lens can have a meniscus shape convex toward the object side on the optical axis.

[0015] According to an embodiment of the present invention, the optical axis distance (CG8) between the eighth lens and the ninth lens and the minimum distance (G8_Min) between the eighth lens and the ninth lens can satisfy the following mathematical formula: 1 < CG8 / G8_min < 10.

[0016] According to an embodiment of the present invention, the optical distance (CG8) between the radius of curvature (L8R2) of the sensor-side surface of the eighth lens and the radius of curvature (L9R1) of the object-side surface of the ninth lens and the minimum distance (G8_Min) between the eighth lens and the ninth lens may satisfy the following mathematical formula: 0 < L8R2 / L9R1 < 5.

[0017] According to an embodiment of the present invention, the sensor-side surface of the third lens has a concave shape on the optical axis, the object-side surface of the fourth lens has a convex shape on the optical axis, and the center distance (CG3) and the edge distance (EG3) between the third lens and the fourth lens may satisfy the following mathematical formula: 2 < CG3 / EG3 < 20.

[0018] According to an embodiment of the present invention, the focal lengths (F3, F6, F7, and F9) of the third lens, the sixth lens, the seventh lens, and the ninth lens satisfy: F3 < 0, F6 < 0, F7 < 0, and F9 < 0, and the combined focal length F13 of the first lens to the third lens may satisfy: F13 > 0, and the combined focal length F49 of the fourth lens and the ninth lens may satisfy: F49 < 0.

[0019] According to an embodiment of the present invention, the refractive indices n3, n5, and n6 of the third lens, the fifth lens, and the sixth lens at the d-line may satisfy: 1.6 < n3, 1.6 < n5, and 1.6 < n6.

[0020] An optical system according to an embodiment of the present invention includes: a first lens group on the object side, which has three or fewer lenses; and a second lens group on the sensor side of the first lens group, which has a plurality of lenses, wherein the first lens group has a positive (+) refractive power on the optical axis, the second lens group has a negative (-) refractive power on the optical axis, the number of lenses in the second lens group is greater than the number of lenses in the first lens group, and at least one of the lens surfaces facing the region between the first lens group and the second lens group has a minimum effective diameter, the sensor-side surface of the lens surface in the second lens group closest to the image sensor has the largest effective diameter, and each lens in the first lens group has a meniscus shape convex toward the object side on the optical axis, and may satisfy the following mathematical formula: 0.5 < TTL / ImgH < 3 and 0.01 < BFL / ImgH < 0.5 (TTL is the distance from the vertex of the object-side surface of the first lens group to the image surface of the image sensor, ImgH is 1 / 2 of the maximum diagonal length of the image sensor, and BFL is the optical axis distance from the image sensor to the sensor-side surface closest to the image sensor).

[0021] According to an embodiment of the present invention, when the focal lengths of each of the first lens group and the second lens group are represented by absolute values, the focal length of the first lens group may be less than the focal length of the second lens group.

[0022] According to an embodiment of the present invention, the first lens group includes a first lens to a third lens that are aligned on the optical axis from the object side toward the sensor, the second lens group includes a fourth lens to a ninth lens that are aligned from the first lens group toward the object side, and the following mathematical expressions can be satisfied: 0.5 < CA_L1S1 / CA_min < 2 and 1 < CA_max / CA_min < 5 (CA_L1S1 is the effective diameter of the object-side surface of the first lens, CA_Min is the minimum value among the effective diameters of the object-side surfaces and the sensor-side surfaces of the first lens to the ninth lens, and CA_Max represents the maximum value among the effective diameters of the object-side surfaces and the sensor-side surfaces of the first lens to the ninth lens).

[0023] According to an embodiment of the present invention, both the object-side surface and the sensor-side surface of the eighth lens can have critical points, and both the object-side surface and the sensor-side surface of the ninth lens can have critical points.

[0024] According to an embodiment of the present invention, the maximum value of the distance between the eighth lens and the ninth lens is the maximum value of the distances between the first lens and the ninth lens, and the maximum thickness of the ninth lens can be the maximum value of the thicknesses from the optical axis of the first lens to the ninth lens to the end of the effective region.

[0025] According to an embodiment of the present invention, the center thickness of each lens and the center distance between adjacent lenses can satisfy the following mathematical expression: 0.5 < ∑CT / ∑CG < 3 (∑CT is the sum of the thicknesses of the first lens to the ninth lens on the optical axis, and ∑CG is the sum of the distances between the first lens and the ninth lens on the optical axis).

[0026] According to an embodiment of the present invention, the following mathematical expression can be satisfied: 0.1 < CA_max / (2 * ImgH) < 1 (CA_max represents the maximum effective diameter among the object-side surface and the sensor-side surface of each lens).

[0027] According to an embodiment of the present invention, the combined focal length (F13) and the effective focal length (F) of the first lens group and the combined focal length (F49) of the second lens group can satisfy the following mathematical expressions: 0 < F13 / F < 5 and 1 < |F49| / F13 < 15.

[0028] A camera module according to an embodiment of the present invention includes: an image sensor; and a filter located between the image sensor and the last lens of the optical system, wherein the optical system includes the above optical system and can satisfy the following mathematical expressions: 1 ≤ F / EPD ≤ 5 and FOV < 120 (F is the total focal length of the optical system, EPD is the entrance pupil diameter of the optical system, and FOV is the field of view).

[0029]

Beneficial Effects

[0030] The optical system and the camera module according to the embodiment may have improved optical characteristics. Specifically, the optical system may have improved aberration characteristics and resolution according to the surface shape, refractive power, thickness of the plurality of lenses, and distances between adjacent lenses among the plurality of lenses.

[0031] The optical system and the camera module according to the embodiment may have improved distortion and aberration characteristics and may have good optical performance in the center and peripheral portions of the field of view (FOV). The optical system according to the embodiment may have improved optical characteristics and a smaller total length of lens (TTL), so that the optical system and the camera module including the optical system may be provided in a slim and compact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a configuration diagram of an optical system according to a first embodiment.

[0033] Figure 2 It is shown Figure 1 An illustration of the relationship between the image sensor, the nth lens, and the n-1th lens in the optical system.

[0034] Figure 3 It is shown Figure 1 A table of lens characteristics of an optical system.

[0035] Figure 4 It is shown Figure 1 A table of aspheric coefficients of the object-side surface and sensor-side surface of the lens of the optical system.

[0036] Figure 5 It is shown Figure 1 A table showing the lens thicknesses in an optical system and the distances between adjacent lenses from the optical axis in a first direction Y orthogonal to the optical axis.

[0037] Figure 6 It is shown Figure 1 A table of Sag values ​​of the object-side surface and sensor-side surface of the nth lens, n-1th lens, and n-2th lens in the optical system.

[0038] Figure 7 yes Figure 1 A graph of the diffraction MTF of an optical system.

[0039] Figure 8 It is shown Figure 1 Graph of the aberration characteristics of an optical system.

[0040] Fig. 9 It shows that according to Figure 2 A graph of the heights in the optical axis direction of the distance between the object side surface and the sensor side surface in the first direction Y in the nth lens and the (n-1)th lens in the optical system.

[0041] Fig.10 is a diagram showing that a camera module according to an embodiment is applied to a mobile terminal. DETAILED DESCRIPTION

[0042] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The technical concept of the present invention is not limited to some embodiments to be described, but can be implemented in various other forms, and one or more components can be selectively combined or replaced to be used within the scope of the technical concept of the present invention. In addition, unless specifically defined and clearly described, the terms (including technical terms and scientific terms) used in the embodiments of the present invention can be interpreted according to the meanings commonly understood by ordinary technicians in the field to which the present invention belongs, and the meanings of commonly used terms (such as terms defined in dictionaries) can be interpreted in the context of considering the contextual meaning of the relevant technology.

[0043] The terms used in the embodiments of the present invention are used to explain the embodiments and are not intended to limit the present invention. In this specification, unless specifically described by a sentence, the singular form may also include the plural form, and when stated as at least one (or one or more) of A, B and C, may include one or more of all combinations that can be combined with A, B and C. When describing the components of the embodiments of the present invention, terms such as the first, second, A, B, (a) and (b) may be used. These terms are only used to distinguish the component from other components, and these terms may not be determined by the nature, sequence, process, etc. of the corresponding constituent elements. Moreover, when describing that a component is "connected", "coupled" or "combined" to another component, the description may include not only directly connecting, coupling or combining to other components, but also "connecting", "coupling" or "combining" by other components between the component and the other component. In addition, in the case of being described as being formed or arranged on "above (upper)" or "below (lower)" of each component, the description includes not only the situation that the two components are in direct contact with each other, but also the situation that one or more other components are formed or arranged between the two components. In addition, when expressed as “above” or “below”, it can refer to a downward direction as well as an upward direction with respect to one element.

[0044] In the description of the present invention, "object side surface" may refer to the surface of the lens facing the object side relative to the optical axis OA, and "sensor side surface" may refer to the surface of the lens facing the imaging surface (image sensor) relative to the optical axis. The convex surface of the lens may mean that the lens surface on the optical axis has a convex shape, and the concave surface of the lens may mean that the lens surface on the optical axis has a concave shape. The radius of curvature, the center thickness, and the distance between the lenses described in the lens data table may mean the value on the optical axis, and the unit is millimeter. The vertical direction may mean the direction perpendicular to the optical axis, and the end of the lens or the lens surface may mean the end or edge of the effective area of ​​the lens through which the incident light passes. Depending on the measurement method, the size of the effective diameter of the lens surface may have a measurement error of up to ±0.4mm. The paraxial area refers to a very narrow area near the optical axis, and is an area where the distance of the light from the optical axis OA is almost zero. In the following, the concave shape or convex shape of the lens surface is described as the optical axis, and the paraxial area may also be included.

[0045] like Figure 1 and Figure 2 As shown, the optical system 1000 according to an embodiment of the present invention may include a plurality of lens groups. In detail, each of the plurality of lens groups includes at least one lens. For example, the optical system 1000 may include a first lens group LG1 and a second lens group LG2 sequentially arranged along the optical axis OA from the object side toward the image sensor 300. Here, the first lens group LG1 is located on the object side and refracts some incident light in the optical axis direction, and the second lens group LG2 may refract some light emitted through the first lens group LG1 to spread to the peripheral portion of the image sensor 300.

[0046] The first lens group LG1 may include at least one lens. The first lens group LG1 may include four or less lenses. For example, the first lens group LG1 may include three lenses. The second lens group LG2 may include at least two or more lenses, and may include 1.5 times more lenses than the lenses of the first lens group LG1. The second lens group LG2 may include seven or less lenses. The number of lenses of the second lens group LG2 may have a difference of three or more and four or less than the number of lenses of the first lens group LG1. For example, the second lens group LG2 may include six lenses.

[0047] The object side surface and the sensor side surface of all lenses of the first lens group LG1 may not be provided with a critical point. In the optical system 1000, at least one or both of the object side surface and the sensor side surface of the nth lens and the n-1th lens may have at least one critical point. Here, n is the lens closest to the image sensor 300 in the optical system 1000, and may range from 8 to 10, preferably 9. The sensor side surface of the nth lens may have a critical point, for example, the critical point P2 of the sensor side surface of the nth lens may be located at 34% or less of the effective radius relative to the optical axis OA, for example, in the range of 14% to 34% or in the range of 19% to 29%.

[0048] The object-side surface of the n-th lens may have a critical point within an end of the effective area from the optical axis OA, and the critical point may be closer to the optical axis OA than the critical point P2 of the sensor-side surface. The critical point of the object-side surface of the n-th lens may be located within a range of 18% or less of the distance from the optical axis OA to the end of the effective area, for example, within a range of 5% to 18% or within a range of 5% to 13%.

[0049] At least one or both of the object-side surface and the sensor-side surface of the n-1th lens may have a critical point. For example, the critical point of the object-side surface of the n-1th lens may be located at least 32% of the effective radius relative to the optical axis OA, for example, in the range of 32% to 52%, or in the range of 37% to 47%, and the critical point of the sensor-side surface may be located at 39% or less of the effective radius based on the optical axis OA, for example, in the range of 19% to 39%, or in the range of 24% to 34%. The critical point is a point at which the sign of the slope value relative to the optical axis OA and the direction perpendicular to the optical axis OA changes from positive (+) to negative (-) or from negative (-) to positive (+), and may refer to a point at which the slope is zero. In addition, the critical point may be a point at which the slope value of a tangent line passing through the lens surface decreases after increasing, or a point at which the slope value decreases and then increases.

[0050] The first lens group LG1 may have a positive (+) refractive power. The second lens group LG2 may have a negative (-) refractive power. The first lens group LG1 and the second lens group LG2 may have different focal lengths. Based on an absolute value, the focal length F_LG2 of the second lens group LG2 may be greater than the focal length F_LG1 of the first lens group LG1. For example, the focal length of the second lens group LG2 may be 1.1 times or more, for example, 1.1 times to 8 times, of the focal length F_LG1 of the first lens group LG1. The number of lenses having a positive (+) refractive power in the optical system 1000 may be greater than the number of lenses having a negative refractive power. In the first lens group LG1, the number of lenses having a positive refractive power may exceed 50%, while the number of lenses having a negative (-) refractive power may be less than 50%. That is, in the optical system, the number of lenses having a negative (-) refractive power may be 4 or less, while the number of lenses having a positive (+) refractive power may be at least 4 or more. Therefore, the optical system 1000 according to the embodiment can improve chromatic aberration and distortion aberration by controlling the refractive power and focal length of each lens group, and can have good optical performance in the center and peripheral parts of the FOV.

[0051] On the optical axis OA, the first lens group LG1 and the second lens group LG2 may have a set distance. The distance between the first lens group LG1 and the second lens group LG2 may be an optical axis distance between a sensor-side surface of a lens closest to the sensor side among the lenses of the first lens group LG1 and an object-side surface of a lens closest to the object side among the lenses of the second lens group LG2. The distance between the first lens group LG1 and the second lens group LG2 on the optical axis OA may be maximum at the center. The sensor-side surface of the lens closest to the sensor among the lenses of the first lens group LG1 has a concave shape on the optical axis OA, and the object-side surface of the lens closest to the object side among the lenses of the second lens group LG2 has a concave shape on the optical axis OA.

[0052] The optical axis distance between the first lens group LG1 and the second lens group LG2 may be greater than the center thickness of the last lens of the first lens group LG1 and the first lens of the second lens group LG2. The optical axis distance between the first lens group LG1 and the second lens group LG2 may be greater than the center thickness of the thinnest lens among the lenses of the first lens group LG1 and the second lens group LG2. The optical axis distance between the first lens group LG1 and the second lens group LG2 may be the third largest distance among the distances between the lenses. The maximum optical axis distance in the optical system 1000 may be the optical axis distance between the nth lens and the n-1th lens.

[0053] The optical axis distance between the first lens group LG1 and the second lens group LG2 may be less than 50% of the optical axis distance of the first lens group LG1, and may be less than 20% of the optical axis distance of the second lens group LG2. The maximum optical axis distance between the lenses may be greater than 50% of the optical axis distance of the first lens group LG1, and less than 50% of the optical axis distance of the second lens group LG2. Therefore, the distance between the first lens group LG1 and the second lens group LG2 and the maximum optical axis distance may be set.

[0054] The optical axis distance of the first lens group LG1 may be smaller than the optical axis distance of the second lens group LG2. Here, the optical axis distance of the first lens group LG1 may be the optical axis distance between the object side surface of the lens closest to the object side in the first lens group LG1 and the sensor side surface of the lens closest to the sensor side. The optical axis distance of the second lens group LG2 may be the optical axis distance between the object side surface of the lens closest to the object side in the second lens group LG2 and the sensor side surface of the lens closest to the sensor. The optical axis distance of the second lens group LG2 may be 2.1 times or more of the optical axis distance of the first lens group LG2, for example, in the range of 2.1 times to 4.1 times, or in the range of 2.6 times to 3.6 times. Therefore, the optical system 1000 provides a longer optical axis distance of the second lens group LG2, so that the incident light can be refracted to the periphery of the image sensor 300, and good optical performance can be achieved not only in the central part of the field of view (FOV) but also in the peripheral part, and chromatic aberration and distortion aberration can be improved.

[0055] The distance between the sensor side surface of the first lens group LG1 and the object side surface of the second lens group LG2 facing each other may gradually decrease toward the edge side of the optical axis OA. At this time, the center distance between the sensor side surface of the first lens group LG1 and the object side surface of the second lens group LG2 has a maximum value, the edge distance is a minimum value, and the maximum distance and the minimum distance may differ by 1.1 times or more, for example, in the range of 1.1 times to 3.1 times. In the optical system 1000, in the optical axis OA or the paraxial region of each lens, the sum of lenses having a convex surface on the object side and a concave surface on the sensor side may be less than 50% of all lenses.

[0056] Each of the plurality of lenses 100 may include an effective area and an ineffective area. The effective area may be an area through which light incident on each lens passes. That is, the effective area may be an effective area in which the incident light is refracted to achieve optical characteristics, and may be represented by an effective diameter or an effective radius. The ineffective area may be arranged around the effective area. The ineffective area is an area in which effective light is not incident from the plurality of lenses, and may be an area further outside the end of the effective area. That is, the ineffective area may be an area that is not related to optical characteristics. In addition, the end of the ineffective area may be an area fixed to a lens barrel (not shown) that houses the lens.

[0057] The optical system 1000 may include an image sensor 300. The image sensor 300 may detect light and convert it into an electrical signal. The image sensor 300 may detect light that sequentially passes through a plurality of lenses 100. The image sensor 300 may include a device capable of sensing incident light, such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

[0058] The optical system 1000 may include a filter 500. The filter 500 may be disposed between the second lens group LG2 and the image sensor 300. The filter 500 may be disposed between the lens closest to the sensor side among the plurality of lenses 100 and the image sensor 300. For example, when the optical system 100 has 9 lenses, the filter 500 may be disposed between the nth lens (i.e., the ninth lens 1090) and the image sensor 300.

[0059] The filter 500 may include at least one of an infrared filter and an optical filter of a cover glass. The filter 500 may allow light of a set wavelength band to pass through and filter out light of a different wavelength band. When the filter 500 includes an infrared filter, radiant heat emitted from external light may be prevented from being transferred to the image sensor 300. In addition, the filter 500 may allow visible light to pass through and reflect infrared light.

[0060] According to an embodiment of the present invention, the TTL can be greater than 2 mm and less than 20 mm. For example, it can be in the range of 4 mm to 12 mm, 4 mm to 10 mm, or 6 mm to 10 mm. The TTL can be in the range of 70% or more of ImgH. For example, it can be in the range of 70% to 130% or in the range of 80% to 120%. Therefore, the ratio of TTL / (ImgH*2) can be set to 60% or less. For example, it can be in the range of 50% to 60%, so that a thin optical system can be provided. In addition, the FOV is set in the range of less than 120 degrees. For example, it can be 70 degrees or more to 119 degrees, or 80 degrees to 100 degrees, so that an optical system with an FOV close to a wide angle or a wide-angle FOV can be designed. Here, the TTL is the distance from the object-side surface of the first lens group LG1 to the optical axis of the image sensor 300, and the ImgH is the length from the center of the image sensor 300 to the diagonal end.

[0061] The maximum effective diameter Max_CA of the lens in the optical system 1000 can be greater than the TTL. The maximum effective diameter Max_CA of the lens in the optical system 1000 can be greater than the ImgH. For example, the maximum effective diameter Max_CA can be in the range of 1.1 < Max_CA / ImgH < 2.1 or in the range of 1.3 ≤ Max_CA / ImgH ≤ 1.8. The maximum effective diameter Max_CA can be in the range of 1.01 ≤ Max_CA / TTL < 2 or in the range of 1.1 ≤ Max_CA / TTL < 1.8. Therefore, by setting the maximum effective diameter Max_CA according to 1 / 2 of the maximum length (i.e., ImgH and TTL) of the image sensor 300, the incident light can be refracted to the periphery of the image sensor 300.

[0062] The optical system 1000 according to the embodiment may include an aperture stop (not shown). The aperture stop may control the amount of light incident on the optical system 1000. The aperture stop may be set at a set position, for example, around the object side surface or sensor side surface of any one lens of the first lens group LG1. The aperture stop may be positioned between the two lenses closest to the object side. As another example, the aperture stop may be set around the sensor side surface closest to the second lens group LG2 in the lens of the first lens group LG1. As another example, the aperture stop may be set around the periphery between the first lens group LG1 and the second lens group LG2. Alternatively, at least one lens selected from the plurality of lenses 100 may be used as an aperture stop. In detail, the object side surface or sensor side surface of one lens selected from the lenses of the first lens group LG1 may be used as an aperture stop for adjusting the amount of light. The optical system 1000 according to the embodiment may also include a reflective member (not shown) for changing the optical path of the object side of the first lens group LG1. The reflective member may be implemented as a prism that reflects incident light toward the lens. Hereinafter, an optical system according to an embodiment will be described in detail.

[0063] Figure 1 is a configuration diagram of an optical system according to a first embodiment, Figure 2 It is shown Figure 1 An explanatory diagram of the relationship between the image sensor, the n-th lens and the n-1-th lens in the optical system of Figure 3 It is shown Figure 1 Table of lens characteristics of optical systems, Figure 4 It is shown Figure 1 Table of aspheric coefficients of the object side surface and sensor side surface of the lens of the optical system, Figure 5 It is shown Figure 1 A table of lens thicknesses in an optical system and distances between adjacent lenses from the optical axis in a first direction Y orthogonal to the optical axis, Figure 6 It is shown Figure 1 A table of Sag values ​​of the object side surface and sensor side surface of the nth lens, the n-1th lens, and the n-2th lens in the optical system, Figure 7 yes Figure 1 A graph of the diffraction MTF of an optical system, Figure 8 It is shown Figure 1 A graph of the aberration characteristics of the optical system, and Fig. 9 It shows that according to Figure 2 A graph of the heights in the optical axis direction of the distance between the object side surface and the sensor side surface in the first direction Y in the nth lens and the (n-1)th lens in the optical system.

[0064] refer to Figure 1 and Figure 2, the optical system 1000 according to the embodiment includes a plurality of lenses 100, and the plurality of lenses 100 may include a first lens 101 to a ninth lens 109. The first to ninth lenses 101 to 109 may be sequentially arranged along the optical axis OA of the optical system 1000. Light corresponding to object information may pass through the first to ninth lenses 101 to 109 and the filter 500 and be incident on the image sensor 300, and the first to third lenses 101-103 may refract or converge some of the incident light in the direction of the optical axis OA, and the fourth to ninth lenses 104-109 may transmit some of the light passing through the fourth lens 104 in a direction away from the optical axis OA.

[0065] The first lens 101 may have a positive (+) or negative (-) refractive power on the optical axis OA. The first lens 101 may have a positive (+) refractive power. The first lens 101 may include a plastic or glass material. For example, the first lens 101 may be made of a plastic material. The first lens 101 may include a first surface S1 defined as an object side surface and a second surface S2 defined as a sensor side surface. On the optical axis OA, the first surface S1 may have a convex shape, and the second surface S2 may have a concave shape. That is, the first lens 101 may have a meniscus shape that is convex toward the object side on the optical axis OA. Alternatively, on the optical axis OA, the first surface S1 may have a convex shape, and the second surface S2 may have a convex shape. That is, the first lens 101 may have a convex shape on both sides of the optical axis OA. At least one of the first surface S1 and the second surface S2 may be an aspherical surface. For example, both the first surface S1 and the second surface S2 may be aspherical surfaces. The aspherical coefficients of the first surface S1 and the second surface S2 are set as follows Figure 4 As shown, L1 is the first lens 101, and S1 / S2 represents the first surface / second surface of L1.

[0066] The second lens 102 may have a positive (+) or negative (-) refractive power on the optical axis OA. The second lens 102 may have a positive (+) refractive power. The second lens 102 may include a plastic or glass material. For example, the second lens 102 may be made of a plastic material. The second lens 102 may include a third surface S3 defined as an object side surface and a fourth surface S4 defined as a sensor side surface. On the optical axis OA, the third surface S3 may have a convex shape and the fourth surface S4 may have a concave shape. That is, the second lens 102 may have a meniscus shape convex toward the object side on the optical axis OA. Alternatively, on the optical axis OA, the third surface S3 may have a convex shape and the fourth surface S4 may have a convex shape. That is, the second lens 102 may have a convex shape on both sides of the optical axis OA. At least one of the third surface S3 and the fourth surface S4 may be an aspherical surface. For example, both the third surface S3 and the fourth surface S4 may be aspherical surfaces. The aspherical coefficients of the third surface S3 and the fourth surface S4 are set as follows Figure 4 As shown, L2 is the second lens 102, and S1 / S2 of L2 represents the first surface / second surface of L2.

[0067] The third lens 103 may have a positive (+) or negative (-) refractive power on the optical axis OA. The third lens 103 may have a negative (-) refractive power. The third lens 103 may include plastic or glass. For example, the third lens 103 may be made of plastic. The third lens 103 may include a fifth surface S5 defined as an object side surface and a sixth surface S6 defined as a sensor side surface. On the optical axis OA, the fifth surface S5 may have a convex shape, and the sixth surface S6 may have a concave shape. That is, the third lens 103 may have a meniscus shape that is convex toward the object side on the optical axis OA. Alternatively, on the optical axis OA, the fifth surface S5 may have a concave shape, and the sixth surface S6 may have a concave shape. At least one of the fifth surface S5 and the sixth surface S6 may be an aspherical surface. For example, both the fifth surface S5 and the sixth surface S6 may be aspherical surfaces. The aspherical coefficients of the fifth surface S5 and the sixth surface S6 are set as follows Figure 4 As shown, L3 is the third lens 103, and S1 / S2 of L3 represents the first surface / second surface of L3.

[0068] The refractive index n3 of the third lens 103 can be the largest among the first to third lenses 101, 102, and 103 and can satisfy: 1.6 < n3. The Abbe number of the third lens 103 can be the smallest among the first to third lenses 101, 102, and 103 and can be less than 30 or less than 25. For example, the Abbe number of the third lens 103 can be 20 or more smaller than the Abbe numbers of the first lens 101 and the second lens 102. The Abbe numbers of the first lens 101 and the second lens 102 can be 45 or more. Therefore, the optical system 1000 can have improved chromatic aberration control characteristics.

[0069] Regarding the effective diameters of the first to third lenses 101, 102, 103, the effective diameter of the first lens 101 can be the largest, and the effective diameter of the third lens 103 can be the smallest. Here, the effective diameter is the average of the effective diameters of the object-side surface and the sensor-side surface of each lens. The effective diameters of the first to third lenses 101, 102, 103 can be 5 mm or less. The radii of curvature of the first to third lenses 101, 102, 103 can be less than 50 mm, for example, less than 40 mm or less than 30 mm, preferably less than 10 mm. Here, the radius of curvature is the average of the radii of curvature of the object-side surface and the sensor-side surface of each lens. By setting the radii of curvature of the first to third lenses 101, 102, and 103 to be less than 50 mm, the light incident efficiency can be improved.

[0070] The fourth lens 104 can have a positive (+) or negative (-) refractive power on the optical axis OA. The fourth lens 104 can have a positive (+) refractive power. The fourth lens 104 can include a plastic or glass material. For example, the fourth lens 104 can be made of a plastic material. For example, the fourth lens 104 can be made of a plastic material. The fourth lens 104 can include a seventh surface S7 defined as the object-side surface and an eighth surface S8 defined as the sensor-side surface. On the optical axis OA, the seventh surface S7 can have a concave shape, and the eighth surface S8 can have a convex shape. That is, the fourth lens 104 can have a meniscus shape that bulges toward the sensor side on the optical axis OA. Alternatively, the seventh surface S7 can have a concave shape on the optical axis OA, and the eighth surface S8 can have a concave shape on the optical axis OA. At least one of the seventh surface S7 and the eighth surface S8 can be an aspherical surface. For example, both the seventh surface S7 and the eighth surface S8 can be aspherical surfaces. The aspherical coefficients of the seventh surface S7 and the eighth surface S8 are set as Figure 4 shown, L4 is the fourth lens 104, and S1 / S2 of L4 represents the first surface / second surface of L4.

[0071] The fifth lens 105 may have a positive (+) or negative (-) refractive power on the optical axis OA. The fifth lens 105 may have a negative positive (+) refractive power. The fifth lens 105 may include a plastic or glass material. For example, the fifth lens 105 may be made of a plastic material. The fifth lens 105 may include a ninth surface S9 defined as an object side surface and a tenth surface S10 defined as a sensor side surface. On the optical axis OA, the ninth surface S9 may have a concave shape and the tenth surface S10 may have a convex shape. That is, the fifth lens 105 may have a meniscus shape convex toward the sensor on the optical axis OA. Alternatively, the ninth surface S9 may have a concave shape on the optical axis OA and the tenth surface S10 may have a concave shape on the optical axis OA. Alternatively, the ninth surface S9 may have a convex shape on the optical axis OA and the tenth surface S10 may have a concave shape or a convex shape on the optical axis OA. At least one of the ninth surface S9 and the tenth surface S10 may be an aspherical surface. For example, the ninth surface S9 and the tenth surface S10 may both be aspherical surfaces. The aspherical coefficients of the ninth surface S9 and the tenth surface S10 are set as follows: Figure 4 As shown, L5 is the fifth lens 105, and S1 / S2 of L5 represents the first surface / second surface of L5.

[0072] The sixth lens 106 may have a positive (+) or negative (-) refractive power on the optical axis OA. The sixth lens 106 may have a negative (-) refractive power. The sixth lens 106 may include a plastic or glass material. For example, the sixth lens 106 may be made of a plastic material. The sixth lens 106 may include an eleventh surface S11 defined as an object side surface and a twelfth surface S12 defined as a sensor side surface. The eleventh surface S11 may have a concave shape on the optical axis OA, and the twelfth surface S12 may have a concave shape on the optical axis OA. That is, the sixth lens 106 may have a concave shape on both sides of the optical axis OA. Alternatively, the eleventh surface S11 may have a concave shape on the optical axis OA, and the twelfth surface S12 may have a convex shape on the optical axis OA. Alternatively, the sixth lens 106 may have a convex shape on both sides of the optical axis OA. At least one of the eleventh surface S11 and the twelfth surface S12 may be an aspherical surface. For example, both the eleventh surface S11 and the twelfth surface S12 may be aspherical surfaces. The aspheric coefficients of the eleventh surface S11 and the twelfth surface S12 are set as follows Figure 4 As shown, L6 is the sixth lens 106, and S1 / S2 of L6 represents the first surface / second surface of L6.

[0073] The seventh lens 107 may have a positive (+) or negative (-) refractive power on the optical axis OA. The seventh lens 107 may have a negative (-) refractive power. The seventh lens 107 may include a plastic or glass material. For example, the seventh lens 107 may be made of a plastic material. The seventh lens 107 may include a thirteenth surface S13 defined as an object side surface and a fourteenth surface S14 defined as a sensor side surface. The thirteenth surface S13 may have a concave shape on the optical axis OA, and the fourteenth surface S14 may have a concave shape on the optical axis OA. Alternatively, the seventh lens 107 may have a meniscus shape convex toward the sensor side or the object side. Alternatively, the seventh lens 107 may have a convex shape on both sides. At least one of the thirteenth surface S13 and the fourteenth surface S14 may be an aspherical surface. For example, the thirteenth surface S13 and the fourteenth surface S14 may both be aspherical surfaces. The aspherical coefficients of the thirteenth surface S13 and the fourteenth surface S14 are set as follows Figure 4 As shown, L7 is the seventh lens 107, and S1 / S2 of L7 represents the first surface / second surface of L7.

[0074] The eighth lens 108 may have a positive (+) or negative (-) refractive power on the optical axis OA. The eighth lens 108 may have a positive (+) refractive power. The eighth lens 108 may include a plastic or glass material. For example, the eighth lens 108 may be made of a plastic material. The eighth lens 108 may include a fifteenth surface S15 defined as an object side surface and a sixteenth surface S16 defined as a sensor side surface. The fifteenth surface S15 may have a convex shape on the optical axis OA, and the sixteenth surface S16 may have a concave shape on the optical axis OA. That is, the eighth lens 108 may have a meniscus shape convex toward the object side on the optical axis OA. Alternatively, the fifteenth surface S15 may have a convex shape on the optical axis OA, and the sixteenth surface S16 may have a convex shape on the optical axis OA. That is, the eighth lens 108 may have a convex shape on both sides. The eighth lens 108 may have a meniscus shape convex toward the sensor or have a concave shape on both sides. At least one of the fifteenth surface S15 and the sixteenth surface S16 may be aspherical. For example, the fifteenth surface S15 and the sixteenth surface S16 may both be aspherical surfaces. The aspherical coefficients of the fifteenth surface S16 and the sixteenth surface S16 are set as follows: Figure 4 As shown, L8 is the eighth lens 108, and S1 / S2 of L8 represents the first surface / second surface of L8.

[0075] The ninth lens 109 may have a positive (+) or negative (-) refractive power on the optical axis OA. The ninth lens 109 may have a negative (-) refractive power. The ninth lens 109 may include a plastic or glass material. For example, the ninth lens 109 may be made of a plastic material. The ninth lens 109 may include a seventeenth surface S17 defined as an object side surface and an eighteenth surface S18 defined as a sensor side surface. The seventeenth surface S17 may have a convex shape on the optical axis OA, and the eighteenth surface S18 may have a concave shape on the optical axis OA. That is, the ninth lens 109 may have a meniscus shape convex toward the object side on the optical axis OA. Alternatively, the seventeenth surface S17 may have a concave shape on the optical axis OA, and the eighteenth surface S18 may have a convex shape on the optical axis OA. Alternatively, the ninth lens 109 may have a concave shape on both sides of the optical axis OA. At least one of the seventeenth surface S17 and the eighteenth surface S18 may be an aspherical surface. For example, both the seventeenth surface S17 and the eighteenth surface S18 may be aspherical surfaces. The aspherical coefficients of the seventeenth surface S17 and the eighteenth surface S18 are set as follows: Figure 4 As shown, L9 is the ninth lens 109, and S1 / S2 of L9 represents the first surface / second surface of L9.

[0076] The first lens group LG1 may include first to third lenses 101, 102, 103, and the second lens group LG2 may include fourth to ninth lenses 104, 105, 106, 107, 108, 109. An optical axis distance TD from the object-side surface of the first lens 101 to the sensor-side surface of the ninth lens 109 satisfies: TD≤10 mm, for example, 7 mm≤TD≤10 mm. The optical axis distance from the object-side surface of the fourth lens 104 to the sensor-side surface of the ninth lens 109 may be 65% or more of TD, for example, in the range of 65% to 75%.

[0077] In the following description, CT1 to CT9 denote center thicknesses of the first to ninth lenses 101 to 109, ET1 to ET9 denote edge thicknesses of the first to ninth lenses 101 to 109, CG1 to CG8 may denote center distances between the first to ninth lenses 101 to 109, and EG1 to EG8 may denote edge distances between the first to ninth lenses 101 to 109.

[0078] In the lens 100, the minimum center thickness CT_Min of each lens satisfies: CT_Min<0.3mm, and the maximum center thickness CT_Max may exceed twice the minimum center thickness, for example, satisfying the following mathematical formula: 0.6mm≤CT_Max. Here, the minimum center thickness of each lens is the center thickness CT4 of the fourth lens 104, and the maximum center thickness is the center thickness CT2 of the second lens 102.

[0079] The central thickness CT9 of the ninth lens 109 can be greater than the central thicknesses CT3 and CT4 of the third lens 103 and the fourth lens 104, and can be less than the central thickness CT8 of the eighth lens 108. The difference between the central thickness CT8 of the eighth lens 108 and the central thickness CT9 of the ninth lens 109 can satisfy the following mathematical formula: CT8 - CT9 ≤ 0.15 mm. Therefore, the optical system 1000 can control incident light and can have improved aberration characteristics and resolution.

[0080] The edge thickness ET9 of the ninth lens 109 is the largest among the edge thicknesses of the lenses, and can satisfy the following mathematical formula: ET9 > CT9. In addition, the first lens 101 and the second lens 102 can satisfy the following mathematical formulas: ET1 < CT1 and ET2 < CT2, while the third lens 103 can satisfy the following mathematical formula: ET3 > CT3.

[0081] The edge thickness of at least one of the first lens 101, the second lens 102, the third lens 103, or the fourth lens 104 can be the minimum edge thickness. The maximum edge thickness can be at least 1.5 times the minimum edge thickness, for example, in the range of 1.5 times to 4 times. Here, the edge thickness is the distance on the optical axis between the end of the effective area of the object side surface of each lens and the end of the effective area of the sensor side surface of each lens.

[0082] In the lens 100, the minimum center distance CG_Min between two adjacent lenses satisfies the following mathematical formula: CG < 0.1 mm, the maximum center distance CG_Max can satisfy the following mathematical formula: CG_Max ≥ 1.3 mm, and the maximum center distance can be more than 10 times or more than 20 times the minimum center distance. Here, the minimum center distance CG_Min is the optical axis distance between the sixth lens 106 and the seventh lens 107, and the maximum center distance CG_Max is the optical axis distance between the eighth lens 108 and the ninth lens 109. Therefore, the optical system 1000 can control incident light and can have improved aberration characteristics and resolution.

[0083] Regarding the edge distance between the lenses 100, the edge distance EG3 between the third lens 103 and the fourth lens 104 can be the minimum, while the edge distance EG8 between the eighth lens 108 and the ninth lens 109 can be the maximum. The edge distance is the distance on the optical axis between the end of the effective area of the sensor side surface of the object side lens and the end of the effective area of the object side surface of the adjacent lens. The maximum edge distance can be 5 times or more the minimum edge distance.

[0084] In the lens 100, the effective radius (semi-aperture) may gradually decrease from the first surface S1 of the first lens 101 to the sensor-side sixth surface S6 of the third lens 103 or the object-side seventh surface S7 of the lens 104. Also, the effective radius may gradually increase from the object-side seventh surface S7 of the fourth lens 104 to the eighteenth surface S18 of the ninth lens 109. Here, the effective radius is the length of a straight line from the optical axis OA to the end of the effective area in a direction orthogonal to the optical axis OA, and the effective radius of each lens is the average of the effective radii of the object-side surface and the sensor-side surface of each lens. Among the object-side surface and the sensor-side surface, the minimum effective radius may be the effective radius of the sensor-side surface S6 of the third lens 103, and the maximum effective radius may be the sensor-side surface S18 of the ninth lens 109. The maximum effective radius may be 2.2 times or more of the minimum effective radius, for example, 2.2 times to 5 times. The effective radius r11 of the first surface S1 of the first lens 101 is larger than the effective radius of the second to sixth surfaces S2-S6, so that light can be guided without loss. The effective radius r92 of the sensor-side eighteenth surface S17 of the ninth lens 109 is the largest in size, so that the incident light can be refracted to the entire area of ​​the image sensor 300. Therefore, the optical system 1000 can have improved chromatic aberration control characteristics, and the vignetting characteristics of the optical system 1000 can be improved by controlling the incident light.

[0085] Regarding the Abbe number, the maximum Abbe number Vd_Max and the minimum Abbe number Vd_Min of each lens may satisfy the following mathematical formula: Vd_Max-Vd_min≥20, and may satisfy: Vd_Max≥45, for example, Vd_Max≥50. The lenses having an Abbe number (Vd) of 45 or more in the optical system 1000 satisfy the following mathematical formula: 4 / nL, where nL is the number of lenses and is in the range of 8 to 10. Therefore, the optical system 1000 may have improved chromatic aberration control characteristics.

[0086] Regarding the refractive index, the maximum refractive index nd_Max of each lens may satisfy the following mathematical formula: nd_Max≥1.6, and the difference between the maximum refractive index nd_Max and the minimum refractive index nd_Min may satisfy the following mathematical formula: nd_Max-nd_Min≥0.07. The number of lenses having a refractive index of 1.6 or more may satisfy: 3 / nL, and the number of lenses having a refractive index less than 1.6 may satisfy: nL-3 / nL. The lenses having a refractive index of 1.6 or more may be the third lens 103, the fifth lens 105, and the sixth lens 106. Therefore, the optical system 1000 may have improved chromatic aberration control characteristics.

[0087] In the absolute value of the effective focal length EFL, the maximum focal length F_Max is, for example, 100 or more, the lens with a focal length of 50 or more or 70 or more is 1 / nL, the lens with the largest focal length is the fifth lens 105, the minimum focal length can be less than 10, and the lens with a focal length of 20 or less can satisfy: 6 / nL. The average value F_Aver of the focal length of each lens can be 20 or more, for example, in the range of 20 to 32.

[0088] In the absolute value of the radius of curvature, the maximum radius of curvature is, for example, 150 mm or more, and the lens with a radius of curvature of 120 mm or more is 1 / nL. The lens surface with the maximum radius of curvature can be the twelfth surface S12, the minimum radius of curvature can be 3 mm or less, and the lens surface with the minimum radius of curvature can be the eighteenth surface S18.

[0089] Among the critical points of the plurality of lenses 100, the object-side surfaces and the sensor-side surfaces of the first to fourth lenses 101 to 104 may not be provided with a critical point. Alternatively, the object-side surface or / and the sensor-side surface of at least one of the first to fourth lenses 101 to 104 may have a critical point. At least one or both of the object-side surface and the sensor-side surface of the fifth lens 105 may not be provided with a critical point or may have at least one critical point. At least one or both of the object-side surface and the sensor-side surface of the sixth lens 106 may not be provided with a critical point or may have at least one critical point.

[0090] The critical point reference of the lens surface of the seventh lens to the ninth lens is Figure 6 The Sag height of each lens surface.

[0091] The thirteenth surface S13 of the seventh lens 107 is L7S1 and may have at least one critical point, which may be located in a range of 27% or less of an effective radius relative to the optical axis OA, for example, in a range of 7% to 27%, or in a range of 12% to 22%. The fourteenth surface S14 of the seventh lens 107 is L7S2 and may have at least one critical point, which may be located in a range of 42% or less of an effective radius relative to the optical axis OA, for example, in a range of 22% to 42%, or in a range of 27% to 37%. The seventh lens 107 having a critical point may refract incident light outward and emit it.

[0092] like Figure 2As shown, the fifteenth surface S15 and the sixteenth surface S16 of the eighth lens 108 are L8S1 and L8S2, and at least one or both of them may have a critical point. For example, the fifteenth surface S15 and the sixteenth surface S16 may both have a critical point. The first critical point P1 of the fifteenth surface S15 may be located at a distance Inf81 that is 32% or more (e.g., in the range of 32% to 52% or in the range of 37% to 47%) of the effective radius r81 of the fifteenth surface S15 from the optical axis OA. The first critical point P1 may be the point on the fifteenth surface S15 that is closest to the image sensor 300.

[0093] The critical point of the sixteenth surface S16 of the eighth lens 108 may be located at a distance from the optical axis OA that is 19% or more (e.g., in a range of 19% to 39% or in a range of 14% to 24%) of the effective radius of the sixteenth surface S16. Therefore, the fifteenth surface S15 and the sixteenth surface S16 may refract light incident through the seventh lens 107 outward. The positions of the critical points of the fifteenth surface S15 and the sixteenth surface S16 may be set to be more outer than the critical point of the thirteenth surface S13 of the seventh lens 107 based on the optical axis OA.

[0094] In the ninth lens 109, the seventeenth surface S17 and the eighteenth surface S18 are L9S1 and L9S2, at least one of which or all of which may have at least one critical point. For example, the seventeenth surface S17 may be located at a distance from the optical axis OA that is 18% or less (e.g., in the range of 5% to 18% or in the range of 5% to 13%) of the effective radius of the seventeenth surface S17. The critical point of the seventeenth surface S17 may be set within a distance of 1 mm or less from the optical axis OA or may be located in the range of 0.3 mm to 0.8 mm. The seventeenth surface S17 may not be provided with a critical point.

[0095] The second critical point P2 of the eighteenth surface S18 of the ninth lens 109 may be located at a distance Inf92 less than or equal to 34% (e.g., in a range of 14% to 34% or in a range of 19% to 29%) of the effective radius r92 of the eighteenth surface S18 from the optical axis OA. Therefore, the seventeenth surface S17 and the eighteenth surface S18 may refract the light refracted by the eighth lens 108 to the peripheral portion of the image sensor 300. Here, the second critical point P2 may be a point in the eighteenth surface S18 closest to the image sensor 300. This point may be a point at which the slope of the normal line K2 on the eighteenth surface S18 and the optical axis OA is zero. In addition, the second critical point P2 may refer to a point at which the slope between the tangent line K1 on the eighteenth surface S18 and the imaginary line K2 extending in the perpendicular direction of the optical axis OA is 0 degrees. Here, the normal line K2 of any point on the sensor side eighteenth surface S18 passing through the ninth lens 109 may have a predetermined angle θ1 with the optical axis OA. The angle θ1 may be less than 65 degrees at most.

[0096] Here, a maximum angle of a tangent line passing through a fifteenth surface S15 of the eighth lens 108 may be greater than a maximum angle of a tangent line passing through an eighteenth surface S18 of the ninth lens 109. A maximum angle of a tangent line passing through a sixteenth surface S16 of the eighth lens 108 may be greater than a maximum angle of a tangent line passing through an eighteenth surface S18 of the ninth lens 109. A maximum angle of a tangent line passing through a seventeenth surface S17 of the ninth lens 109 may be greater than a maximum angle of a tangent line passing through the eighteenth surface S18 of the ninth lens 109.

[0097] Fig. 9 : is a graph showing the sag height of each lens surface of the eighth lens and the ninth lens, wherein L8S1 and L8S2 represent the fifteenth surface S15 and the sixteenth surface S16 of the eighth lens 108, and L9S1 and L9S2 represent the seventeenth surface S17 and the eighteenth surface S18 of the ninth lens 109. Fig. 9 As shown, it can be seen that the critical points of L8S1, L8S2, L9S1 and L9S2 are all within a range of 2.5 mm or less from the optical axis. The sag height is the height of the lens surface on a straight line orthogonal to the center of each lens surface. The critical point of L8S1 can be located further outside than the critical points of the object side surface and the sensor side surface of the eighth lens 108 based on the optical axis. It can be seen that when observed with a straight line orthogonal to the center (e.g., 0) as a reference, the critical point of L9S2, which is the eighteenth surface of the ninth lens 109, is located within a range of 2 mm or less from the center (e.g., 0), or within a range of 1 mm to 2 mm.

[0098] Considering the optical characteristics of the optical system 1000, it is preferred that the positions of the critical points of the eighth lens 108 and the ninth lens 109 are set at positions satisfying the above range. In detail, the positions of the critical points preferably satisfy the above range to control the optical characteristics (e.g., chromatic aberration, distortion characteristics, aberration characteristics, and resolution) of the optical system 1000. Therefore, the path of light emitted to the image sensor 300 through the lens can be effectively controlled. Therefore, the optical system 1000 according to the embodiment has improved optical characteristics not only in the central part of the FOV but also in the peripheral part.

[0099] like Figure 2 As shown, CT9 is the center thickness or optical axis thickness of the ninth lens 109, and ET9 is the end or edge thickness of the effective area of ​​the ninth lens 109. CT8 is the center thickness or optical axis thickness of the eighth lens 108, and ET8 is the end or edge thickness of the effective area of ​​the eighth lens 108. The edge thickness ET8 of the eighth lens 108 is the distance from the end of the effective area of ​​the fifteenth surface S15 to the effective area of ​​the sixteenth surface S16 in the optical axis direction. The edge thickness ET9 of the ninth lens 109 is the distance from the end of the effective area of ​​the seventeenth surface S17 to the effective area of ​​the eighteenth surface S18 in the optical axis direction. CG8 is the optical axis distance (e.g., center distance) from the center of the sensor-side surface of the eighth lens 108 to the center of the object-side surface of the ninth lens 109. That is, CG8 is the distance between the sixteenth surface S16 and the seventeenth surface S17 on the optical axis OA. Similarly, EG8 is the distance from the edge of the eighth lens 108 to the edge of the ninth lens 109 in the optical axis direction (e.g., edge distance). That is, EG8 is the distance in the optical axis direction between a straight line extending outward from the end of the effective area of ​​the sixteenth surface S16 and the end of the effective area of ​​the seventeenth surface S17. Here, the distance between the ends of the effective areas between adjacent lens surfaces is the optical axis distance between a straight line extending from the end with a short effective radius and the end of the effective area facing the straight line. The back focal length (BFL) is the optical axis distance from the image sensor 300 to the last lens.

[0100] In this way, the center thickness and edge thickness of the first to ninth lenses 101 to 109, as well as the center distance and edge distance between two adjacent lenses can be set. Figure 1 and Figure 5As shown, the thickness T1-T9 of each lens and the distance G1-G8 between adjacent lenses can be set. For example, T1-T9 represents the first thickness to the ninth thickness of the first lens to the ninth lens 101 to 109 in the region separated by a predetermined distance (e.g., 0.1 mm or more) relative to the optical axis OA along the first direction Y. In addition, the distance between the first lens 101 and the second lens 102 is the first distance G1, the distance between the second lens 102 and the third lens 103 is the second distance G2, the distance between the third lens 103 and the fourth lens 104 is the third distance G3, the distance between the fourth lens 104 and the fifth lens 105 is the fourth distance G4, the distance between the fifth lens 105 and the sixth lens 106 is the fifth distance G5, the distance between the sixth lens 106 and the seventh lens 107 is the sixth distance G6, the distance between the seventh lens 107 and the eighth lens 108 is the seventh distance G7, and the distance between the eighth lens 108 and the ninth lens 109 can be the eighth distance G8. The first direction Y may include a circumferential direction centered on the optical axis OA or two directions orthogonal to each other, and the distance between two adjacent lenses at both ends of the first direction Y is the effective radius. The end of the effective area of ​​the smaller lens may be used as a reference, and the end of the effective radius may include an error of ±0.2 mm at the end, and may be an edge.

[0101] The first thickness T1 may gradually decrease from the center to the edge of the first lens 101 , and the center thickness of the first lens 101 may exceed 1 times the edge thickness, for example, in a range of 1.1 times to 4 times.

[0102] The second thickness T2 may gradually increase from the center to the edge of the second lens 102 , and the edge thickness of the second lens 102 may exceed 1 times the center thickness, for example, in a range of 1.1 times to 4 times.

[0103] The third thickness T3 may gradually increase from the center to the edge of the third lens 103, and a maximum value of the third thickness T3 may be greater than a minimum value of the first thickness T1 and the second thickness T2, and may be less than a maximum value of the first thickness T1 and the second thickness T2. The maximum value of the third thickness T3 may be 1.1 times or more of the minimum value, for example, in a range of 1.1 times to 2.1 times.

[0104] The fourth thickness T4 may gradually become thinner from the center to the edge of the fourth lens 104, and the maximum value of the fourth thickness T4 may be less than the maximum value of the third thickness T3 and greater than the minimum value. The maximum value of the fourth thickness T4 may be one or more times the minimum value, for example, one to two times.

[0105] The fifth thickness T5 may gradually decrease from the center to the edge of the fifth lens 105, and the maximum value of the fifth thickness T5 may be greater than the maximum values ​​of the third thickness T3 and the fourth thickness T4 and less than the maximum value of the second thickness T2. The maximum value of the fifth thickness T5 may be 1.1 times or more of the minimum value, for example, in the range of 1.1 times to 2.1 times.

[0106] The sixth thickness T6 may gradually increase from the center to the edge of the sixth lens 106, the maximum value of the sixth thickness T6 may be in an area close to the edge, and the minimum value may be at the central thickness. The maximum value of the sixth thickness T6 may be greater than the maximum value of the second thickness T2. The maximum value of the sixth thickness T6 may be 1.3 times or more of the minimum value, for example, in the range of 1.3 times to 2.3 times.

[0107] The seventh thickness T7 may gradually increase from the center to the edge of the seventh lens 107, the maximum value of the seventh thickness T7 may be in an area close to the edge, and the minimum value may be the central thickness. The maximum value of the seventh thickness T7 may be greater than the minimum value of the sixth thickness T6 and less than the maximum value. The maximum value of the seventh thickness T7 may be one or more times the minimum value, for example, one to two times.

[0108] The eighth thickness T8 may be a maximum value at the center of the eighth lens 108, and may be a minimum value within a range of 2.1 mm ± 0.3 mm from the optical axis OA, and the maximum value of the eighth thickness T8 may be less than the maximum value of the second thickness T2 and greater than the maximum value of the seventh thickness T7. The maximum value of the eighth thickness T8 may be 1.2 times or more of the minimum value, for example, within a range of 1.2 times to 2.2 times.

[0109] The ninth thickness T9 may be the smallest at the center of the ninth lens 109 and the largest within the range of 3.3 mm ± 0.3 mm from the optical axis OA, and the maximum value of the ninth thickness T9 may be greater than the maximum values ​​of the first to eighth thicknesses T1-T8. The maximum value of the ninth thickness T9 may be 3.1 times or more of the minimum value, for example, within the range of 3.1 times to 5.1 times.

[0110] In the first distance G1, along the first direction Y, the center distance between the first lens 101 and the second lens 102 may be the smallest, and the edge distance may be the largest. The maximum value of the first distance G1 may be 1.1 times or more of the minimum value, for example, 1.1 times to 2 times. Therefore, the optical system 1000 may effectively control incident light, and light incident through the first lens 101 and the second lens 102 may travel to other lenses through the first distance G1 and maintain good optical performance.

[0111] The second distance G2 can be the distance between the second lens 102 and the third lens 103 in the optical axis direction Z. The second distance G2 can be minimum at the optical axis OA and maximum at the edge. The maximum value of the second distance G2 can be less than the minimum value of the second thickness T2, and can be 4 times or more, for example, 4 to 7 times, the minimum value of the second distance G2. The maximum value of the second distance G2 can be less than the minimum value of the first distance G1. Therefore, the optical system 1000 can have improved optical characteristics, and the aberration characteristics of the optical system 1000 can be improved by the second distance G2.

[0112] The third distance G3 can be the distance between the third lens 103 and the fourth lens 104 in the optical axis direction Z. The third distance G3 can be maximum at the center and minimum at the edge, and the maximum value can be 5 times or more, for example, 5 to 15 times, the minimum value. The maximum value of the third distance G3 can be greater than the maximum value of the first distance G1, and the minimum value can be less than the minimum value of the first distance G1. Therefore, the optical system 1000 can have improved chromatic aberration characteristics, and the vignetting characteristics can be controlled by the third distance G3. The third distance G3 can be the distance between the first group LG1 and the second group LG2.

[0113] The fourth distance G4 can be the distance between the fourth lens 104 and the fifth lens 105 in the optical axis direction Z. The fourth distance G4 can be minimum at the center CG4 and maximum at the edge EG4. The central distance CG4 of the fourth distance G4 can satisfy: CT4 < CG4 < CT5. The maximum value of the fourth distance G4 can be 1 time or more, for example, 1 to 2 times, the minimum value.

[0114] The fifth distance G5 can be the distance between the fifth lens 105 and the sixth lens 106 in the optical axis direction Z. The minimum value of the fifth distance G5 can be the edge distance, and the maximum value can be the distance within 1.3 mm ± 0.3 mm from the optical axis OA. The maximum value of the fifth distance G5 can be 1.4 times or more, for example, in the range of 1.4 to 3.4 times or in the range of 1.9 to 2.9 times, the minimum value. The maximum value of the fifth distance G5 can be greater than the maximum value of the second thickness CT2, and the minimum value of the fifth distance G5 can be less than the minimum value of the second thickness CT2. Therefore, the optical system 1000 can have improved optical characteristics, and due to the fourth distance G4 and the fifth distance G5, it can have good optical performance at the center and peripheral parts of the FOV, and the improved chromatic aberration and distortion can be adjusted.

[0115] The sixth distance G6 may be the distance between the sixth lens 106 and the seventh lens 107 in the optical axis direction. The maximum value of the sixth distance G6 may be located near the edge or within the range of 3.1 mm ± 0.3 mm from the optical axis OA, and the minimum value may be located within the range of 0.7 mm ± 0.3 mm from the optical axis OA. The maximum value of the sixth distance G6 may be 1.7 times or more of the minimum value, for example, within the range of 1.7 times to 3.7 times.

[0116] The seventh distance G7 may be the distance in the optical axis direction between the seventh lens 107 and the eighth lens 108. The seventh distance G7 may be the smallest at the center and the largest within a range of 2.3 mm ± 0.3 mm from the optical axis OA. The maximum value of the seventh distance G7 may be 4 times or more of the minimum value, for example, 4 times to 7 times. The maximum value of the seventh distance G7 may be greater than the maximum value of the sixth distance G6, and may be less than the maximum thickness of the seventh lens 107. Therefore, the optical system 1000 may have improved optical characteristics in the center and peripheral portions of the FOV. In addition, since the seventh lens 107 and the eighth lens 108 are spaced apart by the seventh distance G7 set according to the position, and the size of the effective diameter of the ninth lens 109 may be appropriately controlled, the optical system 1000 may have improved aberration control characteristics.

[0117] The eighth distance G8 may be the distance between the eighth lens 108 and the ninth lens 109 in the optical axis direction. The eighth distance G8 may be minimum within the range of 0.3 mm ± 0.3 mm from the optical axis OA, and maximum within the range of 2.8 mm ± 0.3 mm from the optical axis OA. The maximum value of the eighth distance G8 may be equal to or greater than the maximum value of the ninth thickness CT9, and may be 1.1 times or more of the minimum value of the eighth distance G8, for example, within the range of 1.1 times to 2.1 times. The distortion characteristics and the aberration characteristics may be improved at the center and the peripheral portion of the FOV by the eighth distance G8.

[0118] In the plurality of lenses 100, the number of lenses having a center thickness less than 0.5 mm may be greater than the number of lenses having a center thickness of 0.5 mm or more. In the plurality of lenses 100, the number of lenses having a center thickness less than 0.5 mm may be 5 or less, and the number of lenses having a center thickness greater than 0.5 mm may be 4 or more. Therefore, the optical system 1000 may be configured as a structure having a slim thickness. In the plurality of lens surfaces S1 to S18, the number of surfaces having an effective radius of 3.0 mm or less may be less than the number of surfaces having an effective radius of 3.0 mm or more, for example, 5 or less. Describing the radius of curvature as an absolute value, the radius of curvature of the twelfth surface S12 of the sixth lens 106 in the plurality of lenses 100 may be the largest among the lens surfaces, and the maximum radius of curvature may be 50 times or more of the radius of curvature of the eighteenth surface S18 having the smallest radius of curvature. Describing the focal length as an absolute value, the focal length of the sixth lens 106 in the plurality of lenses 100 may be the largest among the lenses, and the maximum focal length may be 20 times or more of the focal length of the ninth lens 109 having the smallest focal length.

[0119] like Figure 3 As shown, the radius of curvature, the center thickness of the lens (unit: mm), Figure 1 The center distance between the lenses on the optical axis OA of the first lens 101 to the ninth lens 109 (unit: mm), the refractive index at the d line, the Abbe number, the size of the effective radius, and the focal length. In an embodiment of the present invention, the F number may be 1.5 or greater, for example, in the range of 1.5 to 2.5, or in the range of 1.7 to 2.3.

[0120] like Figure 4 As shown, in an embodiment, at least one lens surface of the plurality of lenses 100 may include an aspheric surface having a 30th order aspheric coefficient. For example, the first to ninth lenses 101 to 109 may include lens surfaces having a 30th order aspheric coefficient. As described above, an aspheric surface having a 30th order aspheric coefficient (a value other than "0") can particularly greatly change the aspheric shape of the peripheral portion, thereby being able to well correct the optical performance of the peripheral portion of the FOV.

[0121] Figure 7 is a graph of the diffraction MTF characteristics of the optical system 1000 according to the first embodiment, and Figure 8 is a graph of aberration characteristics. Figure 8 In the aberration diagram, from left to right, spherical aberration, astigmatism field curve, and distortion are measured. Figure 7In the figure, the X-axis can represent the focal length (unit: mm) and the distortion (%), and the Y-axis can represent the height of the image. In addition, the graph of spherical aberration is a graph for light with wavelength bands of about 470nm, about 510nm, about 555nm, about 610nm, and about 650nm, and the graph of astigmatism and distortion aberration is a graph for light with a wavelength band of about 555nm.

[0122] exist Figure 8 In the aberration diagram of , it can be understood that as each curve approaches the Y axis, the aberration correction function is better. That is, the optical system 1000 according to the embodiment can have improved resolution and good optical performance not only in the central part of the FOV but also in the peripheral part.

[0123] In the lens 100 of the optical system 1000 according to the above-described embodiment, the number of lenses having an Abbe number of 45 or more (e.g., in the range of 45 to 70) may be 4, and the number of lenses having a refractive index of 1.6 or more (e.g., in the range of 1.6 to 1.8) may be 3. Therefore, the optical system 1000 can achieve good optical performance in the center and peripheral portions of the FOV and has improved aberration characteristics.

[0124] The optical system 1000 according to the embodiment disclosed above may satisfy at least one or two or more of the following mathematical formulas. Therefore, the optical system 1000 according to the embodiment may have improved optical characteristics. For example, when the optical system 1000 satisfies at least one mathematical formula, the optical system 1000 may effectively control aberration characteristics such as chromatic aberration and distortion aberration, and may have good optical performance not only in the central part of the FOV but also in the peripheral part. The optical system 1000 may have improved resolution and may have a thinner and more compact structure.

[0125] [Math 1]0 <CT1 / CT2<2

[0126] When Math. 1 satisfies the thickness CT1 of the first lens 101 on the optical axis OA and the thickness CT2 of the second lens 102 on the optical axis OA, the optical system 1000 may improve aberration characteristics.

[0127] [Mathematical formula 2]1 <CT3 / ET3<3

[0128] When Math. 2 satisfies a thickness CT3 of the third lens 103 on the optical axis OA and a thickness ET3 of the third lens 103 at an end of the effective area, the optical system 1000 may have improved chromatic aberration control characteristics.

[0129] [Mathematical formula 2-1]1 <CT1 / ET1<5

[0130] [Mathematical formula 2-2]1 <CT2 / ET2<5

[0131] [Mathematical formula 2-3] 1.1 <CT3 / ET3<3

[0132] [Mathematical formula 2-4] 1≤CT4 / ET4<3

[0133] [Mathematical formula 2-5] 1.1 <CT5 / ET5<2.1

[0134] [Mathematical formula 2-6]0 <CT6 / ET6<1.5

[0135] [Mathematical formula 2-7]1 <CT7 / ET7<3

[0136] [Mathematical formula 2-8]1 <CT8 / ET8<5

[0137] [Mathematical formula 2-9] 0.5 <SD / TD<1

[0138] When the ratios of the center thickness to the edge thickness of the second to ninth lenses 102 to 109 in Math. 2-1 to Math. 2-8 are satisfied, the optical system 1000 may have improved chromatic aberration control characteristics.

[0139] SD is an optical axis distance (unit: mm) from the aperture stop to the sensor-side eighteenth surface S18 of the ninth lens 109, and TD is an optical axis distance (unit: mm) from the object-side first surface S1 of the first lens 101 to the sensor-side eighteenth surface S18 of the ninth lens 109. The aperture stop may be provided on the circumference of the object-side surface of the third lens 103. When the optical system 1000 according to the embodiment satisfies Math. 2-9, chromatic aberration of the optical system 1000 may be improved.

[0140] [Mathematical formula 2-10]1<|F_LG2 / F_LG1|<10

[0141] F_LG1 is the focal length of the first lens group LG1, and F_LG2 is the focal length of the second lens group LG2. When the optical system 1000 according to the embodiment satisfies Math 2-10, the chromatic aberration of the optical system 1000 can be improved. That is, when the value of Math 2-10 is close to 1, the distortion aberration can be reduced.

[0142] [Mathematical formula 3]1 <ET9 / CT9<5

[0143] When Math. 3 satisfies an optical axis OA thickness CT9 of the ninth lens 109 and an edge thickness ET9 of the ninth lens 109 at an end of an effective area, the optical system 1000 may affect reduction of distortion aberration and may have improved optical performance.

[0144] [Math 4] 1.6 <n3

[0145] In Math 4, n3 represents the refractive index of the third lens 103 at the d-line. When the optical system 1000 according to the embodiment satisfies Math 4, the optical system 1000 may improve chromatic aberration characteristics.

[0146] [Mathematical formula 4-1]

[0147] 1.50 <n1<1.6

[0148] 1.50 <n9<1.6

[0149] In Math 4-1, n1 is the refractive index of the first lens 101 at the d-line, and n9 is the refractive index of the ninth lens 109 at the d-line. When the optical system 1000 according to the embodiment satisfies Math 4-1, the influence on TTL of the optical system 1000 can be suppressed.

[0150] [Mathematical formula 4-2]

[0151] 1.60 <n6

[0152] 1.60 <n7

[0153] In Math 4-2, n6 is the refractive index of the sixth lens 106 at the d-line, and n7 is the refractive index of the seventh lens 107 at the d-line. When the optical system 1000 according to the embodiment satisfies Math 4-2, the optical system 1000 can improve chromatic aberration characteristics.

[0154] [Math 5] 0.5 <L9S2_max_sag to Sensor<2

[0155] In Math 5, L9S2_max_sag to Sensor represents the distance (unit: mm) from the maximum Sag value of the eighteenth surface S18 on the sensor side of the ninth lens 109 to the image sensor 300 in the direction of the optical axis OA. For example, L9S2_max_sag to Sensor represents the distance (unit: mm) from the center of the ninth lens 109 to the image sensor 300 in the direction of the optical axis OA. When the optical system 1000 according to the embodiment satisfies Math 5, the optical system 1000 can ensure a space in which the filter 500 can be disposed between the plurality of lenses 100 and the image sensor 300, thereby having improved assemblability. In addition, when the optical system 1000 satisfies Math 5, the optical system 1000 can ensure the distance for module manufacturing.

[0156] In the lens data of the embodiment, the position of the filter 500 (specifically, the distance between the last lens and the filter 500) and the distance between the image sensor 300 and the filter 500 are set to facilitate the design of the optical system 1000, and the filter 500 can be freely set within the range where the last lens does not contact the image sensor 300. Therefore, the value of L9S2_max_sag to Sensor in the lens data can be equal to the distance between the object side surface of the filter 500 and the image surface of the image sensor 300 on the optical axis OA, and can be less than the BFL of the optical system 1000, and the position of the filter 500 can be moved within the range where they do not contact the last lens and the image sensor 300, respectively, and have good optical performance. That is, the distance between the critical point P2 of the eighteenth surface S18 of the ninth lens 109 and the image sensor 300 is the smallest, and can be gradually increased toward the end of the effective area.

[0157] [Mathematical formula 6]1 <BFL / L9S2_max_sag to Sensor<2

[0158] In Mathematical Formula 6, BFL represents the distance (unit: mm) from the center of the sensor-side eighteenth surface S18 of the ninth lens 109 closest to the image sensor 300 on the optical axis OA to the image surface of the image sensor 300. When the optical system 1000 according to the embodiment satisfies Mathematical Formula 6, the optical system 1000 can improve the distortion aberration characteristics and can have good optical performance in the peripheral part of the FOV. Here, the maximum Sag value can be the position of the critical point.

[0159] [Math 7]5<|L9S1_max slope|<65

[0160] In Math 7, L9S1_max slope represents a maximum value (degree) of a tangent angle measured on the object-side seventeenth surface S17 of the ninth lens 109. In detail, L7S1_max slope on the seventeenth surface S17 represents an angle value (degree) of a point having a maximum tangent angle relative to a virtual line extending in a direction perpendicular to the optical axis OA. When the optical system 1000 according to the embodiment satisfies Math 7, the optical system 1000 can control the occurrence of lens flare.

[0161] [Math 8] 0.2 <L9S2 Inflection Point<0.6

[0162] In Mathematical Expression 8, L9S2 Inflection Point can represent the position of the critical point on the eighteenth surface S18 on the sensor side of the ninth lens 109. Specifically, in L9S2, the inflection point can be the ratio of the distance from the optical axis OA to the critical point on the optical axis when the distance from the end of the effective region is 1. In L9S2, the critical point can be located within the range of 1.5 mm ± 0.3 mm from the optical axis OA. When the optical system 1000 according to the embodiment satisfies Expression 8, the influence on the thinness ratio of the optical system 1000 can be suppressed.

[0163] [Mathematical Expression 9] 1 < CG8 / G8_min < 40

[0164] In Mathematical Expression 9, CG8 represents the distance on the optical axis OA between the eighth lens 108 and the ninth lens 109 (unit: mm), and G8_min represents the minimum distance between the eighth lens 108 and the ninth lens 109 (unit: mm). When the optical system 1000 according to the embodiment satisfies Mathematical Expression 9, the optical system 1000 can improve the distortion aberration characteristics and can have good optical performance in the peripheral part of the FOV. Mathematical Expression 9 can be satisfied as: 1 < CG8 / G8_min ≤ 20 or 1 < CG8 / G8_min ≤ 10.

[0165] [Mathematical Expression 10] 0 < CG8 / EG8 < 0.5

[0166] In Mathematical Expression 10, CG8 represents the distance on the optical axis OA between the eighth lens 108 and the ninth lens 109 (unit: mm), and EG8 represents the optical axis distance at the end of the effective regions of the eighth lens 108 and the ninth lens 109. When the optical system 1000 according to the embodiment satisfies Mathematical Expression 10, good optical performance can be obtained even in the central and peripheral parts of the FOV. In addition, the optical system 1000 can reduce distortion, thus having improved optical performance.

[0167] [Mathematical Expression 11] 0.01 < CG1 / CG8 < 1

[0168] In Mathematical Expression 11, CG1 represents the optical axis distance between the first lens 101 and the second lens 102 (unit: mm), and CG8 represents the optical axis distance between the eighth lens 108 and the ninth lens 109. When the optical system 1000 according to the embodiment satisfies Mathematical Expression 11, the optical system 1000 can improve the aberration characteristics and control the size of the optical system 1000. For example, the TTL decreases.

[0169] [Mathematical Expression 11-1] 3 < CA_L9S2 / CG8 < 20

[0170] In Math 11-1, CA_L9S2 is the effective diameter of the maximum lens surface, and is the size of the effective diameter of the sensor-side eighteenth surface S18 of the ninth lens 109. When the optical system 1000 according to the embodiment satisfies Math 11-1, the optical system 1000 can improve aberration characteristics and control TTL reduction.

[0171] [Math 12]0 <CT1 / CT8<2

[0172] When Math. 12 satisfies thickness CT1 of first lens 101 on optical axis OA and thickness CT8 of eighth lens 108 on optical axis OA, optical system 1000 may have improved aberration characteristics. In addition, optical system 1000 has good optical performance under a set FOV and may control TTL.

[0173] [Math 13]0 <CT7 / CT8<5

[0174] When Math Formula 13 satisfies the thickness CT7 of the seventh lens 107 on the optical axis OA and the thickness CT8 of the eighth lens 108 on the optical axis, the optical system 1000 can relax the manufacturing accuracy of the eighth lens 108 and the ninth lens 109 and can improve the optical performance of the central and peripheral parts of the FOV.

[0175] [Math 14]0 <L8R2 / L9R1<5

[0176] In Math 14, L8R2 represents the curvature radius (unit: mm) of the optical axis OA of the sixteenth surface S16 of the eighth lens 108, and L9R1 represents the curvature radius (unit: mm) on the optical axis of the seventeenth surface S17 of the ninth lens 109. When the optical system 1000 according to the embodiment satisfies Math 14, the aberration characteristics of the optical system 1000 can be improved.

[0177] [Equation 15] 0<(CG8-EG8) / (CG8)<2

[0178] When Math. 15 satisfies the center distance and edge distance between the seventh lens 107 and the eighth lens 108, the optical system 1000 can reduce distortion and have improved optical performance. When the optical system 1000 according to the embodiment satisfies Math. 15, the optical performance of the center and peripheral portions of the FOV can be improved.

[0179] [Mathematical formula 16]1 <CA_L1S1 / CA_L3S1<1.5

[0180] In Math 16, CA_L1S1 represents the size (unit: mm) of the effective diameter CA (clear aperture) of the first surface S1 of the first lens 101, and CA_L3S1 represents the size (unit: mm) of the effective diameter CA of the fifth surface S5 of the third lens 103. When the optical system 1000 according to the embodiment satisfies Math 16, the optical system 1000 can control light incident to the first lens group LG1, and can have improved aberration control characteristics.

[0181] [Mathematical formula 17] 1<51 <CA_L8S2 / CA_L4S2<5

[0182] In Math 17, CA_L4S2 represents the size (unit: mm) of the effective diameter CA of the eighth surface S8 of the fourth lens 104, and CA_L8S2 represents the size (unit: mm) of the effective diameter CA of the sixteenth surface S16 of the eighth lens 108. When the optical system 1000 according to the embodiment satisfies Math 17, the optical system 1000 can control light incident to the second lens group LG2 and can improve aberration characteristics.

[0183] [Math 18] 0.5 <CA_L3S2 / CA_L4S1<1.5

[0184] In Math 18, CA_L3S2 represents the size (unit: mm) of the effective diameter CA of the sixth surface S6 of the third lens 103, and CA_L4S1 represents the size (unit: mm) of the effective diameter CA of the seventh surface S7 of the fourth lens 104. When the optical system 1000 according to the embodiment satisfies Math 18, the optical system 1000 can improve chromatic aberration and control vignetting to obtain optical performance.

[0185] [Mathematical formula 19] 0.1 <CA_L5S2 / CA_L7S2<1

[0186] In Math 19, CA_L5S2 represents the size (unit: mm) of the effective diameter of the tenth surface S10 of the fifth lens 105, and CA_L7S2 represents the size (unit: mm) of the effective diameter of the fourteenth surface S14 of the seventh lens 107. When the optical system 1000 according to the embodiment satisfies Math 19, the optical system 1000 can improve chromatic aberration.

[0187] [Mathematical formula 19-1]1 <CA_L9S2 / CA_L1S1<5

[0188] In Mathematical Formula 19-1, CA_L9S1 represents the size (unit: mm) of the effective diameter of the seventeenth surface S17 of the ninth lens 109, and CA_L1S1 represents the size (unit: mm) of the effective diameter of the first surface S1 of the first lens 101. When the optical system 1000 according to the embodiment satisfies Mathematical Formula 19-1, the optical system 1000 can improve chromatic aberration.

[0189] [Mathematical Formula 20] 2 < CG3 / EG3 < 20

[0190] In Mathematical Formula 20, CG3 is the distance on the optical axis OA between the third lens 103 and the fourth lens 104, and EG4 is the marginal distance between the third lens 103 and the fourth lens 104. When the optical system 1000 according to the embodiment satisfies Mathematical Formula 20, the optical system 1000 can reduce chromatic aberration, improve aberration characteristics, and control vignetting to obtain optical performance.

[0191] [Mathematical Formula 21] 0 < CG7 / EG7 < 1

[0192] In Mathematical Formula 21, CG7 and EG7 represent the central distance and the marginal distance between the seventh lens 107 and the eighth lens 108. When the optical system 1000 according to the embodiment satisfies Mathematical Formula 21, good optical performance can be obtained even at the center and the peripheral part of the FOV, and distortion can be suppressed.

[0193] At least one of Mathematical Formula 20 and Mathematical Formula 21 may further include at least one of Mathematical Formula 21-1 to Mathematical Formula 21-6.

[0194] [Mathematical Formula 21-1] 0 < CG1 / EG1 < 1

[0195] [Mathematical Formula 21-2] Satisfy: 0 < CG2 / EG2 < 1, and can be smaller than the value of Mathematical Formula 21-1.

[0196] [Mathematical Formula 21-3] Satisfy: 0 < CG4 / EG4 < 1.2, and can be larger than the value of Mathematical Formula 21-1.

[0197] [Mathematical Formula 21-4] Satisfy: 1 < CG5 / EG5 < 10, and can be smaller than the value of Mathematical Formula 20.

[0198] [Mathematical Formula 21-5] Satisfy: 0 < CG6 / EG6 < 1, and can be larger than the value of Mathematical Formula 21-2.

[0199] [Mathematical Formula 21-6] Satisfy: 0 < CG8 / EG8 < 1, and can be larger than the value of Mathematical Formula 21-3.

[0200] [Mathematical Formula 22] 0 < G8_max / CG8 < 2

[0201] In Math 22, G8_Max represents the maximum distance among the distances (unit: mm) between the eighth lens 108 and the ninth lens 109. When the optical system 1000 according to the embodiment satisfies Math 22, optical performance in the peripheral portion of FOV can be improved, and distortion of aberration characteristics can be suppressed.

[0202] [Mathematical formula 23]1 <CT6 / CG6<10

[0203] In Math 23, CT6 represents the thickness of the sixth lens 106 on the optical axis OA (unit: mm), and CG6 represents the distance between the sixth lens 106 and the seventh lens 107 on the optical axis OA (unit: mm). When the optical system 1000 according to the embodiment satisfies Math 23, the optical system 1000 can reduce the size of the effective diameters of the fifth lens and the sixth lens and the center distance between adjacent lenses, and improve the optical performance of the peripheral portion of the FOV.

[0204] [Mathematical formula 24]1 <CT7 / CG7<10

[0205] When Mathematical Formula 24 satisfies the thickness CT7 of the seventh lens 107 on the optical axis OA and the distance CG7 between the seventh lens 107 and the eighth lens 108, the optical system 1000 can reduce the size and distance of the effective diameters of the sixth lens, the seventh lens and the eighth lens, and improve the optical performance of the peripheral portion of the FOV.

[0206] [Math 25]0 <CT8 / CG8<1

[0207] When Mathematical Formula 25 satisfies the thickness CT8 of the eighth lens 108 on the optical axis OA and the distance CG8 between the eighth lens 108 and the ninth lens 109, the optical system 1000 can reduce the size of the effective diameter of the eighth lens and the center distance between the eighth lens and the ninth lens, and improve the optical performance of the peripheral portion of the FOV.

[0208] [Math 26] 1<|L5R2 / CT5|<100

[0209] When Math Formula 26 satisfies the curvature radius L5R2 of the tenth surface S10 of the fifth lens 105 and the thickness CT5 of the fifth lens 105 on the optical axis, the optical system 1000 can control the refractive power of the fifth lens 105 and improve the optical performance of light incident to the second lens group LG2.

[0210] [Math 27] 0<|L5R1 / L7R1|<10

[0211] When Math 27 satisfies the curvature radius L5R1 of the ninth surface S9 of the fifth lens 105 and the curvature radius L7R1 of the thirteenth surface S13 of the seventh lens 107, the shapes and refractive powers of the fifth lens and the seventh lens can be controlled and the optical performance can be improved, and the optical performance of the second lens group LG2 can be improved. Math 27 may include at least one of the following Math 27-1 to Math 27-9.

[0212] [Mathematical formula 27-1]0 <L1R1 / L1R2<1.2

[0213] [Mathematical formula 27-2]1 <L2R2 / L2R1<10

[0214] [Mathematical formula 27-3]1 <L3R1 / L3R2<5

[0215] [Mathematical formula 27-4]1 <L4R1 / L4R2<5

[0216] [Mathematical formula 27-5]1 <L5R1 / L5R2<3

[0217] [Mathematical formula 27-6]5<|L6R2 / L6R1|<30

[0218] [Mathematical formula 27-7]1<|L7R1 / L7R2|<5

[0219] [Mathematical formula 27-8]2 <L8R2 / L8R1<20

[0220] [Mathematical formula 27-9]1 <L9R1 / L9R2<10

[0221] [Math 28]0 <CT_Max / CG_Max<2

[0222] In Math 28, CT_max represents the thickest thickness (unit: mm) of each of the plurality of lenses 100 on the optical axis OA, and CG_max represents the maximum value (unit: mm) of the air gap or distance between the plurality of lenses 100 on the optical axis. When the optical system 1000 according to the embodiment satisfies Math 28, the optical system 1000 has good optical performance at a set FOV and focal length, and the size of the optical system 1000 is reduced, for example, TTL is reduced.

[0223] [Mathematical formula 29] 0.5 < ∑CT / ∑CG < 3

[0224] In Math 29, ΣCT represents the sum of the thickness of each of the plurality of lenses 100 on the optical axis OA (unit: mm), and ΣCG represents the sum of the distances between two adjacent lenses of the plurality of lenses 100 on the optical axis OA (unit: mm). When the optical system 1000 according to the embodiment satisfies Math 29, the optical system 1000 has good optical performance at a set FOV and focal length, and reduces the size of the optical system 1000, for example, reduces TTL.

[0225] [Mathematical formula 30] 10<ΣIndex<30

[0226] In Math 30, ΣIndex represents the sum of the refractive index of the d-line of each of the plurality of lenses 100. When the optical system 1000 according to the embodiment satisfies Math 30, the TTL of the optical system 1000 can be controlled and the resolution can be improved. Here, the average refractive index of the first to ninth lenses 101 to 109 may be 1.5 or more.

[0227] [Mathematical formula 31] 10<ΣAbbe / ΣIndex<50

[0228] In Math 31, ΣAbbe represents the sum of the Abbe numbers of each lens in the plurality of lenses 100. When the optical system 1000 according to the embodiment satisfies Math 31, the optical system 1000 may have improved aberration characteristics and resolution. The average Abbe number of the first to ninth lenses 101 to 109 may be 30 or more.

[0229] [Math 32]0<|Max_distortion|<5

[0230] In Math 32, Max_distortion represents the maximum value of distortion in the region from the center (0.0F) to the diagonal end (1.0F) based on the optical characteristics detected by the image sensor 300. When the optical system 1000 according to the embodiment satisfies Math 32, the optical system 1000 can improve distortion characteristics.

[0231] [Math 33]0 <EG_Max / CT_Max<2

[0232] In Math 33, CT_max represents the thickest thickness (unit: mm) of each lens in the plurality of lenses 100 on the optical axis OA, and EG_Max represents the maximum edge distance between two adjacent lenses. When the optical system 1000 according to the embodiment satisfies Math 33, the optical system 1000 has a set FOV and focal length, and can have good optical performance in the peripheral portion of the FOV.

[0233] [Math 34] 0.5 <CA_L1S1 / CA_min<2

[0234] In Math 34, CA_L1S1 represents an effective diameter (unit: mm) of the first surface S1 of the first lens 101, and CA_Min represents a minimum effective diameter (unit: mm) of the first to eighteenth surfaces S1-S18. When the optical system 1000 according to the embodiment satisfies Math 34, light incident through the first lens 101 can be controlled, and a slim optical system can be provided while maintaining optical performance.

[0235] [Mathematical formula 35]1 <CA_max / CA_min<5

[0236] In Math 35, CA_max represents the maximum effective diameter (unit: mm) among the object-side surface and the sensor-side surface of the plurality of lenses 100, and represents the maximum effective diameter among the effective diameters (unit: mm) of the first to eighteenth surfaces S1-S18. When the optical system 1000 according to the embodiment satisfies Math 35, the optical system 1000 can provide a slim and compact optical system while maintaining optical performance.

[0237] [Mathematical formula 36]1 <CA_max / CA_Aver<3

[0238] In Math 36, CA_max represents the maximum effective diameter (unit: mm) among the object-side surface and the sensor-side surface of the plurality of lenses, and CA_Aver represents the average of the effective diameters of the object-side surface and the sensor-side surface of the plurality of lenses. When the optical system 1000 according to the embodiment satisfies Math 36, a slim and compact optical system can be provided.

[0239] [Math 37] 0.1 <CA_min / CA_Aver<1

[0240] In Math 37, CA_min represents the smallest effective diameter (unit: mm) among the object-side surface and the sensor-side surface of the plurality of lenses. When the optical system 1000 according to the embodiment satisfies Math 37, a slim and compact optical system can be provided.

[0241] [Math 38] 0.1 <CA_max / (2×ImgH)<1

[0242] In Math Formula 38, CA_max represents the largest effective diameter among the object side surface and the sensor side surface of the plurality of lenses 100, and ImgH represents the distance (unit: mm) from the center (0.0F) of the image sensor 300 overlapping the optical axis OA to the diagonal end (1.0F). That is, ImgH represents 1 / 2 of the maximum diagonal length (unit: mm) of the effective area of ​​the image sensor 300. When the optical system 1000 according to the embodiment satisfies Math Formula 38, the optical system 1000 has good optical performance in the center and peripheral parts of the FOV, and a slim and compact optical system can be provided. Here, ImgH can be in the range of 4 mm to 10 mm.

[0243] [Math 39] 0.5 <TD / CA_max<1.5

[0244] In Math 39, TD is the maximum optical axis distance (unit: mm) from the object-side surface of the first lens group LG1 to the sensor-side surface of the second lens group LG2. For example, TD is the distance from the first surface S1 of the first lens 101 to the eighteenth surface S18 of the ninth lens 109 on the optical axis OA. When the optical system 1000 according to the embodiment satisfies Math 39, a slim and compact optical system can be provided.

[0245] [Math 40]0 <F / L8R2<1

[0246] In Math 40, F represents the total focal length of the optical system 1000 (unit: mm), and L8R2 represents the radius of curvature (unit: mm) of the sixteenth surface S16 of the eighth lens 108. When the optical system 1000 according to the embodiment satisfies Math 40, the optical system 1000 can reduce the size of the optical system 1000, for example, reduce TTL.

[0247] Mathematical formula 40 may also include the following mathematical formula 40-1.

[0248] [Mathematical formula 40-1]1 <F / F#<6

[0249] F# can represent F number.

[0250] [Mathematical formula 41]1 <F / L1R1<10

[0251] In Formula 41, L1R1 represents the curvature radius of the first surface S1 of the first lens 101 (unit: mm), and F represents the effective focal length (unit: mm). When the optical system 1000 according to the embodiment satisfies Formula 41, the size of the optical system 1000 can be reduced, for example, TTL can be reduced.

[0252] [Math 42]0 <EPD / L9R2<10

[0253] In Mathematical Expression 42, EPD represents the entrance pupil diameter of the optical system 1000 (unit: mm), and L9R2 represents the radius of curvature of the eighteenth surface S18 of the ninth lens 109 (unit: mm). When the optical system 1000 according to the embodiment satisfies Mathematical Expression 42, the optical system 1000 can control the overall brightness and can have good optical performance at the center and peripheral portions of the FOV. Mathematical Expression 42 may further include the following Mathematical Expression 42-1.

[0254] [Mathematical Expression 42-1] 1 < EPD / F# < 3

[0255] [Mathematical Expression 43] 0.5 < EPD / L1R1 < 8

[0256] Mathematical Expression 42 represents the relationship between the EPD of the optical system and the radius of curvature of the first surface S1 of the first lens 101, and can control the incident light.

[0257] [Mathematical Expression 44] 0 < F13 / F < 5

[0258] In Mathematical Expression 44, F is the total focal length of the optical system 1000 (unit: mm). Mathematical Expression 44 establishes the relationship between the focal length F13 of the first lens group LG1 and the total focal length. When the optical system 1000 according to the embodiment satisfies Mathematical Expression 44, the optical system 1000 can control the TTL of the optical system 1000.

[0259] [Mathematical Expression 44-1] 0 < F13 / F3 < 5

[0260] In Mathematical Expression 44-1, F13 represents the combined focal length of 1 - 3 lenses, that is, the focal length of the first lens group (unit: mm), and F3 represents the focal length of the third lens 103 (unit: mm). When the optical system 1000 according to the embodiment satisfies Mathematical Expression 44-1, it can have an appropriate refractive power to control the optical path incident on the first lens group and improve the resolution. Mathematical Expression 44 may further include at least one of the following Mathematical Expressions 44-1 to 44-6.

[0261] [Mathematical Expression 44-1] 0 < F1 / F2 < 5 (F1 and F2 are the focal lengths of the first lens and the second lens)

[0262] [Mathematical Expression 44-2] 0 < F1 / F < 4

[0263] [Mathematical Expression 44-3] 0 < F1 / F13 < 3

[0264] [Mathematical Expression 44-4] F3 < 0, F6 < 0, F7 < 0, and F9 < 0

[0265] In Math 44-4, F3, F6, F7, and F9 represent focal lengths (unit: mm) of the third lens 103, the sixth lens 106, the seventh lens 107, and the ninth lens 109. When Math 44-4 satisfies the above range, the resolution can be improved by controlling the refractive power of each lens, and the optical system can be provided in a slim and compact size. Each of F3, F6, F7, and F9 can be, for example, in the range of -1 mm to -30 mm.

[0266] [Mathematical formula 44-5]F49<0

[0267] In Math 44-5, F49 represents the combined focal length of the fourth lens to the ninth lens (unit: mm). When Math 44-5 satisfies the above range, the resolving power can be improved by controlling the refractive power of the second lens group, and the optical system can be provided in a slim and compact size. In Math 45-5, for example, F49 can be in the range of -1 mm to -50 mm.

[0268] [Mathematical formula 44-6]0 <F13<20

[0269] In mathematical formula 44-6, F13 represents the combined focal length of the first lens, the second lens, and the third lens (unit: mm). When mathematical formula 44-6 satisfies the above range, the factors affecting the reduction of distortion aberration can be controlled by controlling the refractive power of the first lens, the second lens, and the third lens. In mathematical formula 44-6, for example, the range of F13 can be from 5 mm to 15 mm.

[0270] [Mathematical formula 45] 1<|F49| / F13<15

[0271] In Math 46, F13 represents the composite focal length of the first lens to the third lens (unit: mm), and F49 represents the composite focal length of the fourth lens to the ninth lens (unit: mm). Math 46 establishes the relationship between the focal length F_LG1 of the first lens group LG1 and the focal length F_LG2 of the second lens group LG2. In an embodiment, the composite focal length of the first lens to the third lens may have a positive (+) value, and the composite focal length of the fourth lens to the ninth lens may have a negative (-) value. When the optical system 1000 according to the embodiment satisfies Math 46, the optical system 1000 may improve aberration characteristics such as chromatic aberration and distortion aberration.

[0272] [Mathematical formula 46]2 <TTL<20

[0273] In Math 46, TTL represents a distance (unit: mm) from the vertex of the first surface S1 of the first lens 101 to the image surface of the image sensor 300 on the optical axis OA. By setting TTL to less than 20 in Math 46, a slim and compact optical system can be provided.

[0274] [Mathematical formula 47]2 <ImgH

[0275] Math 47 sets the diagonal size (2*ImgH) of the image sensor 300 to 4 mm or more, thereby providing an optical system with high resolution.

[0276] [Math 48] BFL < 2.5

[0277] Math 48 makes the BFL smaller than 2.5 mm, thereby ensuring the installation space of the filter 500 and improving the assembly of components through the gap between the image sensor 300 and the last lens, thereby improving the coupling reliability.

[0278] [Mathematical formula 49]2 <F<20

[0279] In Math Formula 49, the total focal length F can be set to suit the optical system.

[0280] [Formula 50]FOV<120

[0281] In Math 51, FOV represents the field of view of the optical system 1000, and an optical system of less than 120 degrees may be provided. The FOV may be greater than 70 degrees, for example, in the range of 70 to 115 degrees.

[0282] [Math 51] 0.5 <TTL / CA_max<2

[0283] In Math 52, CA_max represents the maximum effective diameter (unit: mm) among the object-side surface and the sensor-side surface of the plurality of lenses, and TTL represents the distance (unit: mm) from the vertex of the first surface S1 of the first lens 101 to the image surface of the image sensor 300 on the optical axis OA. Math 51 sets the relationship between the total optical axis length and the maximum effective diameter of the optical system, thereby providing a slim and compact optical system.

[0284] [Math 52] 0.5 <TTL / ImgH<3

[0285] Mathematical formula 52 can set the TTL of the optical system and the diagonal length (ImgH) of the image sensor 300 from the optical axis. When the optical system 1000 according to the embodiment satisfies mathematical formula 53, the optical system 1000 ensures BFL to apply a relatively large-sized image sensor 300, for example, a large-sized image sensor 300 of about 1 inch, and can have a small TTL and can have a high-definition implementation and a slim structure.

[0286] [Math 53] 0.01 <BFL / ImgH<0.5

[0287] [Mathematical formula 53-1]2 <ImgH / BFL<10

[0288] Mathematical formula 53 and mathematical formula 53-1 can set the optical axis distance between the image sensor 300 and the last lens and the length of the image sensor 300 from the optical axis in the diagonal direction. When the optical system 1000 according to the embodiment satisfies mathematical formula 53 or mathematical formula 53-1, the optical system 1000 can ensure the BFL to apply a relatively large image sensor 300, for example, a larger image sensor 300 of about 1 inch, and minimize the distance between the last lens and the image sensor 300, thereby having good optical characteristics in the center and peripheral parts of the FOV.

[0289] [Mathematical formula 54]7 <TTL / BFL<13

[0290] Math 54 can set the total optical axis length (TTL) of the optical system and the optical axis distance (BFL) between the image sensor 300 and the last lens (unit: mm). When the optical system 1000 according to the embodiment satisfies Math 54, the optical system 1000 ensures the BFL and can be set to be slim and compact.

[0291] [Math 55] 0.5 <F / TTL<1.5

[0292] Math 55 can set the total focal length F and the total optical axis length TTL of the optical system 1000. Therefore, a slim and compact optical system can be provided.

[0293] [Mathematical formula 55-1]0 <F# / TTL<0.5

[0294] Math 55-1 can set the F number F# and the total optical axis length (TTL) of the optical system 1000. Therefore, a slim and compact optical system can be provided.

[0295] [Mathematical formula 56]3 <F / BFL<10

[0296] Mathematical formula 57 can set the total focal length F of the optical system 1000 and the optical axis distance (BFL) between the image sensor 300 and the last lens (unit: mm). When the optical system 1000 according to the embodiment satisfies mathematical formula 56, the optical system 1000 can have a set FOV, can have an appropriate focal length, and can provide a slim and compact optical system. In addition, the optical system 1000 can minimize the distance between the last lens and the image sensor 300, so that the optical system 1000 can have good optical characteristics in the peripheral part of the FOV.

[0297] [Math 57] 0.1 <F / ImgH<3

[0298] Math 57 may set the total focal length F (unit: mm) of the optical system 1000 and the diagonal length (ImgH) of the optical axis of the image sensor 300. The optical system 1000 may have improved aberration characteristics by applying a relatively large image sensor 300 (eg, a large image sensor 300 of about 1 inch).

[0299] [Mathematical formula 58]1 <F / EPD<5

[0300] Equation 58 can set the overall focal length F (unit: mm) and the entrance pupil diameter of the optical system 1000. Therefore, the overall brightness of the optical system can be controlled.

[0301] [Math 59]0 <n3 / n4<1.5

[0302] When the refractive indices n3 and n4 of the third lens 103 and the fourth lens 104 in Math. 59 satisfy the above range, the optical system can improve the resolution. In addition, the refractive indices n1 and n2 of the first lens 101 and the second lens 102 at the d line can satisfy: <n1 / n2<1.5。

[0303] [Math 60]

[0304]

[0305] In Mathematical Formula 60, Z is Sag and may represent the distance from any position on the aspherical surface to the vertex of the aspherical surface in the direction of the optical axis. Y may represent the distance from any position on the aspherical surface to the optical axis in a direction perpendicular to the optical axis. c may represent the curvature of the lens, and K may represent the cone constant. In addition, A, B, C, D, E, and F may represent aspherical constants.

[0306] The optical system 1000 according to the embodiment may satisfy at least one or two or more of Mathematical Formulas 1 to 59. In this case, the optical system 1000 may have improved optical characteristics. In detail, when the optical system 1000 satisfies at least one or two or more of Mathematical Formulas 1 to 59, the optical system 1000 has improved resolution, and may improve aberration and distortion characteristics. In addition, the optical system 1000 may ensure BFL to apply a large-size image sensor 300, and may minimize the distance between the last lens and the image sensor 300, and thus may have good optical performance in the center and peripheral portions of the FOV. In addition, when the optical system 1000 satisfies at least one of Mathematical Formulas 1 to 59, it may include a relatively large image sensor 300, have a relatively small TTL value, and may provide a thinner and more compact optical system and a camera module having the optical system.

[0307] In the optical system 1000 according to the embodiment, the distance between the plurality of lenses 100 may have a value set according to a region.

[0308] Table 1 relates to each item of the above mathematical formula in the optical system 1000 according to the embodiment, and relates to TTL, BFL, total focal length F value, ImgH, focal lengths F1, F2, F3, F4, F5, F6, F7, F8 and F9, synthetic focal length, and edge thickness ET of each of the first to ninth lenses. Here, the edge thickness of the lens refers to the thickness in the optical axis direction Z at the end of the effective area of ​​the lens, and the unit is mm.

[0309]

Table 1

[0310] item value item value F 7.847 ET1 0.2501 F1 16.087 ET2 0.2500 F2 10.536 ET3 0.3471 F3 -18.789 ET4 0.2500 F4 39.935 ET5 0.2500 F5 189.424 ET6 0.3554 F6 -16.150 ET7 0.2907 F7 -14.044 ET8 0.3044 F8 5.400 ET9 0.4798 F9 -6.245 EG1 0.415 F_LG1 9.129 EG2 0.181 F_LG2 -22.677 EG3 0.050 EPD 3.946 EG4 0.318 BFL 0.881 EG5 0.100 TD 7.919 EG6 0.215 Ih 8.004 EG7 0.095 TTL 8.800 EG8 1.081 F-number 1.988 ∑CT 3.829 FOV 90 ∑CG 1.947

[0311] Table 2 involves Figure 1 Result values ​​of the above mathematical formulas 1 to 59 in the optical system 1000. Referring to Table 2, it can be seen that the optical system 1000 satisfies at least one, two or more, or three or more of the mathematical formulas 1 to 59. In detail, it can be seen that the optical system 1000 according to the embodiment satisfies all of the mathematical formulas 1 to 59. Therefore, the optical system 1000 can improve the optical performance and optical characteristics at the central part and the peripheral part of the FOV.

[0312]

Table 2

[0313]

[0314]

[0315]

[0316] Fig.10 2 is a diagram showing that a camera module according to an embodiment is applied to a mobile terminal. Fig.10 , the mobile terminal 1 may include a camera module 10 disposed on the rear side. The camera module 10 may include an image capture function. In addition, the camera module 10 may include at least one of an autofocus function, a zoom function, and an OIS function. The camera module 10 may process a still image or a video frame obtained by the image sensor 300 in a shooting mode or a video call mode. The processed image frame may be displayed on a display unit (not shown) of the mobile terminal 1 and may be stored in a memory (not shown). In addition, although not shown in the figure, the camera module may also be disposed on the front side of the mobile terminal 1.

[0317] For example, the camera module 10 may include a first camera module 10A and a second camera module 10B. At this time, at least one of the first camera module 10A and the second camera module 10B may include the above-mentioned optical system 1000. Therefore, the camera module 10 may have a slim structure and may have improved distortion and aberration characteristics. In addition, the camera module 10 may have good optical performance even in the center and peripheral parts of the FOV.

[0318] In addition, the mobile terminal 1 may further include an autofocus device 31. The autofocus device 31 may include an autofocus function using a laser. The autofocus device 31 may be mainly used under conditions where the autofocus function of the image using the camera module 10 is degraded, such as a distance of 10m or less or a dark environment. The autofocus device 31 may include a light-emitting unit including a vertical cavity surface emitting laser (VCSEL) semiconductor device, and a light receiving unit that converts light energy into electrical energy, such as a photodiode. In addition, the mobile terminal 1 may further include a flash module 33. The flash module 33 may include a light-emitting element that emits light therein. The flash module 33 may be operated by the camera operation of the mobile terminal or the control of the user.

[0319] The features, structures, effects, etc. described in the above embodiments are all included in at least one embodiment of the present invention, and are not necessarily limited to one embodiment. In addition, the features, structures, and effects described in each embodiment can be combined or modified by a technician in the field to which the embodiment belongs relative to other embodiments. Therefore, the contents related to these combinations and modifications should be understood to be included in the scope of the present invention. Although described based on the embodiments, this is only an example, and the present invention is not limited thereto. It will be clear to those skilled in the art that various modifications and applications not described above can be made without departing from the essential features of the present embodiment. For example, each component specifically shown in the embodiment can be modified and implemented. And the differences related to these modifications and applications should be understood to be included in the scope of the present invention defined in the appended claims.

Claims

1. An optical system, comprising: The first lens to the ninth lens are arranged along the optical axis in the direction from the object side to the sensor side, Wherein, the first lens and the third lens have different refractive powers on the optical axis, wherein the first to third lenses have a meniscus shape convex toward the object side on the optical axis, wherein the object-side surface of each of the eighth lens and the ninth lens has a convex shape on the optical axis, Among them, the following mathematical formula is satisfied: 0.5<∑CT / ∑CG<3 0 <CT_Max / CG_Max<2 (∑CT is the sum of the center thicknesses of the first lens to the ninth lens, ∑CG is the sum of the optical axis distances between the first lens to the ninth lens, CT_Max is the maximum value of the center thickness of each lens, and CG_Max is the maximum value of the optical axis distances).

2. The optical system according to claim 1, in, The object side surface of the eighth lens has a first critical point, The sensor side surface of the eighth lens has a second critical point. The second critical point is arranged to be closer to the outside than the first critical point relative to the optical axis.

3. The optical system according to claim 2, in, The first critical point is set in a range of 32% to 52% of a distance from the optical axis of the object-side surface of the eighth lens to an end of an effective area, and the second critical point is set in a range of 14% to 34% of a distance from the optical axis of the sensor-side surface of the ninth lens to the end of the effective area.

4. An optical system according to any one of claims 1 to 3, in, A maximum angle of a tangent line passing through a sensor-side surface of the eighth lens is greater than a maximum angle of a tangent line passing through a sensor-side surface of the ninth lens.

5. The optical system according to any one of claims 1 to 3, in, Each of the eighth lens and the ninth lens has a meniscus shape that is convex toward the object side on the optical axis.

6. The optical system according to any one of claims 1 to 3, in, The optical axis distance CG8 between the eighth lens and the ninth lens and the minimum distance G8_Min between the eighth lens and the ninth lens satisfy the following mathematical formula: <CG8 / G8_min<10。 7. An optical system according to any one of claims 1 to 3, in, An optical distance CG8 between a curvature radius L8R2 of the sensor-side surface of the eighth lens and a curvature radius L9R1 of the object-side surface of the ninth lens and a minimum distance G8_Min between the eighth lens and the ninth lens satisfy the following mathematical formula: <L8R2 / L9R1<5。 8. An optical system according to any one of claims 1 to 3, in, The sensor-side surface of the third lens has a concave shape on the optical axis, wherein the object-side surface of the fourth lens has a convex shape on the optical axis, The center distance CG3 and the edge distance EG3 between the third lens and the fourth lens satisfy the following mathematical formula: <CG3 / EG3<20。 9. The optical system according to any one of claims 1 to 3, in, The focal lengths F3, F6, F7, and F9 of the third lens, sixth lens, seventh lens, and ninth lens respectively satisfy: F3 < 0, F6 < 0, F7 < 0, and F9 < 0, wherein the combined focal length F13 of the first lens to the third lens satisfies: F13 > 0, wherein the combined focal length F49 of the fourth lens and the ninth lens satisfies: F49 < 0.

10. The optical system according to any one of claims 1 to 3, in, the refractive indices n3, n5, and n6 of the third lens, fifth lens, and sixth lens at the d-line satisfy: 1.6 < n3, 1.6 < n5, and 1.6 < n6.

11. An optical system, comprising: a first lens group on the object side, having three or fewer lenses; and a second lens group on the sensor side of the first lens group, having a plurality of lenses, wherein the first lens group has a positive (+) refractive power on the optical axis, wherein the second lens group has a negative (-) refractive power on the optical axis, wherein the number of lenses in the second lens group is greater than the number of lenses in the first lens group, wherein at least one lens surface of the lens surfaces facing the region between the first lens group and the second lens group has a minimum effective diameter, wherein the sensor-side surface of the lens surface of the second lens group closest to the image sensor has the maximum effective diameter, wherein each lens of the first lens group has a meniscus shape convex toward the object side on the optical axis, wherein the following mathematical expressions are satisfied: 0.5 < TTL / ImgH < 3 0.01 < BFL / ImgH < 0.5 (TTL is the optical axis distance from the vertex of the object-side surface of the first lens group to the image surface of the image sensor, ImgH is 1 / 2 of the maximum diagonal length of the image sensor, and BFL is the optical axis distance from the image sensor to the sensor-side surface closest to the image sensor).

12. The optical system according to claim 11, in, when the focal lengths of each of the first lens group and the second lens group are expressed as absolute values, the focal length of the first lens group is less than the focal length of the second lens group.

13. The optical system according to claim 11, in, the first lens group includes a first lens to a third lens aligned on the optical axis from the object side toward the sensor, wherein the second lens group includes a fourth lens to a ninth lens from the first lens group toward the sensor, wherein the following mathematical expressions are satisfied: 0.5 < CA_L1S1 / CA_min < 2 1 < CA_max / CA_min < 5 (CA_L1S1 is the effective diameter of the object-side surface of the first lens, CA_Min is the minimum value of the effective diameters of the object-side surfaces and sensor-side surfaces of the first lens to the ninth lens, and CA_Max represents the maximum value of the effective diameters of the object-side surfaces and sensor-side surfaces of the first lens to the ninth lens).

14. The optical system according to claim 13, in, both the object-side surface and the sensor-side surface of the eighth lens have critical points, Wherein, both the object-side surface and the sensor-side surface of the ninth lens have critical points.

15. The optical system according to claim 14, in, The maximum value of the distance between the eighth lens and the ninth lens is the maximum value of the distances between the first lens to the ninth lens. The maximum thickness of the ninth lens is the maximum value of the thicknesses from the optical axes of the first lens to the ninth lens to the ends of the effective region.

16. The optical system according to claim 14, in, The center thickness of each lens and the center distance between adjacent lenses satisfy the following mathematical formula: 0.5<∑CT / ∑CG<3 (ΣCT is the sum of thicknesses of the first lens to the ninth lens on the optical axis, and ΣCG is the sum of distances between the first lens to the ninth lens on the optical axis).

17. An optical system according to any one of claims 11 to 16, in, Satisfies the following mathematical formula: 0.1 <CA_max / (2*ImgH)<1 (CA_max represents the largest effective diameter of the object-side surface and the sensor-side surface of each of the lenses).

18. The optical system according to claim 13, in, The composite focal length F13 of the first lens group, the effective focal length F, and the composite focal length F49 of the second lens group satisfy the following mathematical formula: 0 <F13 / F<5 1<|F49| / F13<15.

19. A camera module, comprising: Image sensor; as well as a filter disposed between the image sensor and the last lens of the optical system, wherein the optical system comprises the optical system according to any one of claims 1 and 11, Among them, the following mathematical formula is satisfied: 1≤F / EPD≤5 FOV≤120 (F is the total focal length of the optical system, EPD is the entrance pupil diameter of the optical system, and FOV is the field of view).

Images