Optical system and camera module including the same

Abstract

An optical system disclosed in an embodiment includes: first to eighth lenses disposed along an optical axis from an object side toward a sensor side; the first lens has a positive (+) refractive power on the optical axis and has a shape in which the object-side surface is convex, and among the first to eighth lenses, the number of meniscus lenses which are convex toward the object side on the optical axis is 5 or more; each of an object-side surface and a sensor-side surface of the seventh lens has a critical point, each of an object-side surface and a sensor-side surface of the eighth lens has a critical point, and the critical point of the object-side surface of the eighth lens is closer to the optical axis than the critical point of the object-side surface and the sensor-side surface of the seventh lens.

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] The camera module captures an object and stores it as an image or video, and the camera module is installed in various applications. In particular, the camera module is produced in a very small size and is applied not only to portable devices such as smart phones, tablets, and laptops, but also to drones and vehicles to provide various functions. 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 can perform an auto focus function (AF) for aligning the lens focus by automatically adjusting the distance between the image sensor and the imaging lens, and can perform a zoom function for zooming in or out by increasing or decreasing the magnification of a distant object through a zoom lens. In addition, the camera module adopts image stabilization (IS) technology to correct or prevent image stability problems caused by an unstable fixture or camera movement caused by the user's movement.

[0003] The most important element of such a camera module for obtaining an image is an imaging lens that forms the image. Recently, attention to high efficiency such as high image quality and high resolution is increasing, and in order to achieve this goal, research on an optical system including multiple lenses is being conducted. For example, research is being conducted on the use of multiple imaging lenses with positive (+) refractive power and / or negative (-) refractive power to achieve an efficient optical system. When the optical system includes multiple lenses, there is a problem that it is difficult to obtain excellent optical properties and aberration characteristics. In addition, when multiple lenses are included, due to the thickness, spacing, size, etc. of the multiple lenses, the overall length, height, etc. may increase, thereby increasing the overall size of the module including multiple lenses.

[0004] In addition, the size of the image sensor increases to achieve high resolution and high definition. However, when the size of the image sensor increases, the TTL (total track length) of the optical system including a plurality of lenses also increases, thereby increasing the thickness of the camera and the mobile terminal including the optical system. Therefore, a new optical system capable of solving the above problems is needed. Summary of the invention

[0005] Technical issues

[0006] Embodiments of the present invention provide an optical system having improved optical performance. Embodiments provide an optical system having excellent optical performance at the central portion and the peripheral portion of a field of view. Embodiments provide an optical system capable of having a thin structure.

[0007] Technical solution

[0008] The optical system according to an embodiment of the present invention includes: a first lens to an eighth lens, the first lens to the eighth lens being arranged along the optical axis from the object side toward the sensor side; the first lens has a positive (+) refractive power on the optical axis and has a shape with a convex object-side surface, and the number of meniscus lenses that protrude from the optical axis toward the object side among the first lens to the eighth lens is 5 or more; each of the object-side surface and the sensor-side surface of the seventh lens has a critical point, each of the object-side surface and the sensor-side surface of the eighth lens has a critical point, and the critical point of the object-side surface of the eighth lens is set to be closer to the optical axis than the critical points of the object-side surface and the sensor-side surface of the seventh lens, and the following formulas are satisfied: 1.5 < ImgH / ∑CT < 2.2, 1.6 < ImgH / ∑CG < 2.3 (ImgH is 1 / 2 of the maximum diagonal length of the image sensor, ∑CT is the sum of the central thicknesses of the first lens to the eighth lens, and ∑CG is the sum of the central distances of the first lens to the eighth lens).

[0009] According to an embodiment of the present invention, the critical point of the object-side surface of the eighth lens may be closer to the optical axis than the critical point of the sensor-side surface of the eighth lens. Each of the object-side surface and the sensor-side surface of the fourth lens may have a critical point. Each of the object-side surface and the sensor-side surface of the fifth lens may have a critical point.

[0010] According to an embodiment of the present invention, the optical system satisfies the following formula: (TTL * n) > FOV (TTL is the optical axis distance from the center of the object-side surface of the first lens to the image surface of the image sensor, n is the total number of lenses, and FOV is the field of view).

[0011] According to an embodiment of the present invention, the optical system may satisfy the following formulas: ImgH < TTL, 150 < TTL * ImgH (ImgH is 1 / 2 of the maximum diagonal length of the image sensor, and TTL is the optical axis distance from the center of the object-side surface of the first lens to the image surface of the image sensor).

[0012] According to an embodiment of the present invention, the refractive index of the first lens satisfies: 1.50 < n1 < 1.6, the refractive index of the second lens satisfies: 1.60 < n2, and n2 is the maximum refractive index among the refractive indices of the lenses.

[0013] According to an embodiment of the present invention, the first lens, the second lens, the fourth lens, the fifth lens, and the seventh lens have a meniscus shape that protrudes from the optical axis toward the object side, and the eighth lens may have a meniscus shape that protrudes from the optical axis toward the object side.

[0014] According to an embodiment of the present invention, the maximum effective diameter CA_Max of the object side surface and the sensor side surface of each of the first lens to the eighth lens may satisfy the following formula: 0.1 < CA_Max / (2*ImgH) < 1 and 0.5 < TTL / CA_Max < 2 (ImgH is 1 / 2 of the maximum diagonal length of the image sensor, and TTL is the optical axis distance from the object side surface of the first lens to the image surface of the image sensor).

[0015] According to an embodiment of the present invention, the optical system may satisfy the following formula: (v2*n2) < (v1*n1) (v1 is the Abbe number of the first lens, v2 is the Abbe number of the second lens, n1 is the refractive index of the first lens, and n2 is the refractive index of the second lens).

[0016] The optical system according to an embodiment of the present invention includes: a first lens having a meniscus shape convex toward the object; a second lens disposed on the sensor side of the first lens; an nth lens closest to the image sensor; an (n - 1)th lens disposed on the object side of the nth lens; more than three lenses are disposed between the second lens and the (n - 1)th lens, wherein the second lens has the smallest effective diameter among the lenses of the optical system, and the nth lens has the largest effective diameter among the lenses of the optical system, and the first lens to the nth lens are aligned with the optical axis (n is 10 or less), the number of lenses having positive refractive power among the n lenses is greater than the number of lenses having negative refractive power, the sensor side surface of the nth lens is the smallest among the curvature radii of the object side surface and the sensor side surface of the lenses, the lens surface having the largest effective diameter among the lenses is CA_max, 1 / 2 of the diagonal length of the image sensor is ImgH, and the following formula may be satisfied: 0.5 ≤ CA_max / (2*ImgH) < 1.

[0017] According to an embodiment of the present invention, wherein the total effective focal length is F, the curvature radius of the object side surface of the first lens is L1R1, and the curvature radius of the sensor side surface of the nth lens is LnR2, the following formula may be satisfied: 1 < F / L1R1 < 5, 2 < F / LnR2 < 4.5.

[0018] According to an embodiment of the present invention, the sum of the central thicknesses of the lenses is ΣCT, the sum of the optical axis distances between two adjacent lenses is ΣCG, the maximum central thickness of the lenses is CT_Max, and the maximum optical axis distance between adjacent lenses is CG_Max, the following formulas may be satisfied: 0.5 < ΣCT / ΣCG < 1.2 and the formula: 15 < (CT_Max + CG_Max)*n < 45.

[0019] According to an embodiment of the present invention, the object side surface and the sensor side surface of the nth lens have a critical point, the object side surface and the sensor side surface of the n-1th lens have a critical point, and the critical point of the sensor side surface of the nth lens can be set to be closer to the optical axis than the critical point of the object side surface and the critical point of the sensor side surface of the n-1th lens.

[0020] A camera module according to an embodiment of the present invention includes: an image sensor disposed on a sensor side of a plurality of lenses; and an optical filter disposed between the image sensor and a last lens, and the optical system may include the above-mentioned optical system.

[0021] Beneficial Effects

[0022] The optical system and the camera module according to the embodiment may have improved optical performance. Specifically, due to the surface shape, refractive power, thickness, and the distance between adjacent lenses in the plurality of lenses, the optical system may have improved aberration characteristics and resolution. The optical system and the camera module according to the embodiment may have improved distortion and aberration characteristics, and may have good optical performance at the center and the periphery of the field of view (FOV). The optical system according to the embodiment may have improved optical characteristics and a smaller total track length (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

[0023] Figure 1 is a configuration diagram of an optical system and a camera module according to an embodiment of the present invention.

[0024] Figure 2 It is shown Figure 1 An explanatory diagram of the relationship between an image sensor, an nth lens, and an n-1th lens of an optical system.

[0025] Figure 3 It is shown Figure 1 A table of lens data for an optical system.

[0026] Figure 4 yes Figure 1 Examples of aspheric coefficients of lenses.

[0027] Figure 5 It is shown Figure 1 A table showing the thickness of lenses and the distance between lenses in an optical system according to the direction perpendicular to the optical axis.

[0028] Figure 6 It is shown Figure 1 A table of sag values ​​of the object-side and sensor-side surfaces of the seventh lens and the eighth lens in the optical system of FIG.

[0029] Figure 7 yes Figure 1 A graph of the diffraction MTF of an optical system.

[0030] Figure 8 It is shown Figure 1 A graph showing the aberration characteristics of an optical system.

[0031] Fig. 9 It is shown Figure 1 A graph of the concave values ​​of the object-side surface and the sensor-side surface of the nth lens and the n-1th lens in the optical system.

[0032] Fig.10 is a configuration diagram of an optical system and a camera module according to a second embodiment of the present invention.

[0033] Fig.11 It is shown Fig.10 An explanatory diagram of the relationship between an image sensor, an nth lens, and an n-1th lens of an optical system.

[0034] Fig.12 It is shown that according to Fig.10 A table of lens data for an embodiment of an optical system.

[0035] Fig.13 yes Fig.10 Examples of aspheric coefficients of lenses.

[0036] Fig.14 It is shown Fig.10 A table showing the thickness of lenses and the distance between lenses in an optical system according to the direction perpendicular to the optical axis.

[0037] Fig.15 It is shown Fig.10 A table of concave values ​​of the object-side surface and sensor-side surface of the nth lens and the n-1th lens in the optical system.

[0038] Fig.16 It is shown Fig.10 A table of inclination angles of the object-side surface and the sensor-side surface of the n-th lens and the n-1-th lens.

[0039] Fig.17 yes Fig.10 A graph of the diffraction MTF of an optical system.

[0040] Fig.18 It is shown Fig.10 A graph showing the aberration characteristics of an optical system.

[0041] Fig.19 It is shown Fig.10A graph of the concave values ​​of the object-side surface and the sensor-side surface of the nth lens and the n-1th lens in the optical system.

[0042] Fig. 20 is a diagram illustrating a camera module applied to a mobile terminal according to an embodiment. DETAILED DESCRIPTION

[0043] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The technical spirit of the present invention is not limited to some embodiments to be described, and can be implemented in respective other forms, and within the scope of the technical spirit of the present invention, one or more components can be selectively combined and used interchangeably. In addition, unless explicitly defined and described, the terms (including technical terms and scientific terms) used in the embodiments of the present invention can be interpreted as meanings that are generally understood by ordinary technicians in the field to which the present invention belongs, and commonly used terms (such as terms defined in dictionaries) should be able to interpret the meanings of these terms in consideration of the contextual meanings of the relevant technologies.

[0044] The terms used in the embodiments of the present invention are for explaining the embodiments and are not intended to limit the present invention. In this specification, unless otherwise specifically stated in the phrase, the singular form may also include the plural form, and in the case of stating at least one (or one or more) of A and (and) B, C, one or more combinations may be included in all combinations that can be combined with A, B and C. When describing the components of the embodiments of the present invention, the terms such as the first, second, A, B, (a) and (b) may be used. Such terms are only used to distinguish components from other components and are not determined by the terms of the properties, sequence or program of the corresponding constituent elements. And when describing that a component is "connected", "combined" or "engaged" to another component, the description may include not only direct connection, combination or engagement to another component, but also "connection", "combination" or "engagement" by another component between the component and the other component. In addition, in the case of being described as being formed or arranged "above (up)" or "below (below)" of each component, the description may include 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.

[0045] In the description of the present invention, the "object side surface" may refer to the surface of the lens facing the object side on the optical axis OA, and the "sensor side surface" may refer to the surface of the lens facing the image surface (image sensor) with the optical axis as the reference. The convex surface of the lens may mean that the lens surface or the paraxial area on the optical axis has a convex shape, and the concave surface of the lens may mean that the lens surface or the paraxial area 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 represent the values ​​on the optical axis. The vertical direction may refer to the direction perpendicular to the optical axis, and the end of the lens or the lens surface may refer to the end or edge of the effective area through which the incident light of the lens passes. Depending on the measurement method, the size of the effective diameter of the lens surface may have a measurement error of up to ±0.4 mm. The paraxial area refers to a very narrow area near the optical axis, and is an area where the distance of the light falling from the optical axis OA is almost zero. In the following, the concave or convex shape of the lens surface is described on the optical axis, and the paraxial area may also be included.

[0046] Figure 1 1 is a diagram showing an optical system 1000 and a camera module having the same according to an embodiment of the present invention. Figure 1 , the optical system 1000 or the camera module may include a plurality of lens groups LG1 and LG2. Each of the plurality of lens groups LG1 and LG2 includes at least one lens, and may include a first lens group LG1 and a second lens group LG2 arranged in sequence along the optical axis OA from the object side toward the image sensor 300. The number of lenses of the second lens group LG2 may be greater than the number of lenses of the first lens group LG1, for example, between two and four times the number of lenses of the first lens group LG1. The first lens group LG1 may include three or less lenses, for example, two lenses. The second lens group LG2 may include five or more lenses. The second lens group LG2 may include a greater number of lenses than the first lens group LG1, for example, seven or less lenses. Compared with the number of lenses of the first lens group LG1, the number of lenses of the second lens group LG2 may be at least five or more, and, for example, may include six lenses.

[0047] In the optical system 1000, the total track length (TTL) can be less than 70% of the diagonal length of the image sensor 300, for example, in the range of 40% to 69% or 50% to 65%. TTL is the distance from the object side surface of the first lens 101 closest to the object to the image surface of the image sensor 300 on the optical axis OA, and the diagonal length of the image sensor 300 is the maximum diagonal length of the image sensor 300, and can be twice the distance ImgH from the optical axis OA to the diagonal end. Therefore, a thinner optical system and a camera module having the optical system can be provided. The total number of lenses in the first lens group LG1 and the second lens group LG2 is seven to nine.

[0048] The first lens group LG1 may have a positive (+) refractive power. The second lens group LG2 may have a positive (+) refractive power. The first lens group LG1 and the second lens group LG2 have different focal lengths and the same refractive power, and thus may have good optical performance in the center and peripheral portion of the field of view (FOV). The refractive power is the reciprocal of the focal length. The first lens group LG1 may include a group of lenses having a meniscus convex toward the object. The second lens group LG2 may have a meniscus convex toward the sensor side of the lens closest to the object. The optical system 1000 may include less than ten lenses or less than nine lenses. The first lens group LG1 refracts light incident through the object side to collect it, and the second lens group LG2 may refract light emitted through the first lens group LG1 so that it may propagate to the periphery of the image sensor 300. Therefore, the sensor side surface of the first lens group LG1 may be concave on the optical axis, and the object side surface of the second lens group LG2 may be convex on the optical axis. The sensor side surface of the first lens group LG1 and the object side surface of the second lens group LG2 face each other.

[0049] When expressed as an absolute value, the focal length of the second lens group LG2 may be greater than the focal length of the first lens group LG1. For example, the absolute value of the focal length F_LG2 of the second lens group LG2 may be more than 1.1 times the absolute value of the focal length F_LG1 of the first lens group LG1, for example, in the range of 1.1 times to 2 times. Therefore, the optical system 1000 according to the embodiment may have improved aberration control characteristics, for example, chromatic aberration and distortion aberration, by controlling the refractive power and focal length of each lens group, and may have good optical performance at the center and peripheral portions of the FOV.

[0050] The optical axis distance between the first lens group LG1 and the second lens group LG2 on the optical axis OA is the separation distance on the optical axis OA, and may be the optical axis distance between the sensor side surface of the lens closest to the sensor in the first lens group LG1 and the object side surface of the lens closest to the object in the lens of the second lens group LG2. The optical axis distance between the first lens group LG1 and the second lens group LG2 is greater than the center thickness of the last lens of the first lens group LG1 and may be less than the center thickness of the lens closest to the object in the second lens group LG2. The optical axis distance between the first lens group LG1 and the second lens group LG2 may be more than 27% of the optical axis distance of the first lens group LG1, for example, it may be in the range of 27% to 47% or 32% to 42% of the optical axis distance of the first lens group LG1. Here, the optical axis distance of the first lens group LG1 is the distance in the optical axis distance between the object side surface closest to the object in the first lens group LG1 and the sensor side surface of the lens closest to the sensor. The optical axis distance between the first lens group LG1 and the second lens group LG2 may be less than 10% of the optical axis distance of the second lens group LG2, for example, may be in the range of 2% to 10% or 4% to 4%. The optical axis distance of the second lens group LG2 is the distance on the optical axis between the object side surface of the lens of the second lens group LG2 closest to the object and the sensor side surface of the lens closest to the sensor.

[0051] The lens with the smallest effective diameter in the first lens group LG1 may be the lens closest to the second lens group LG2. The lens with the smallest effective diameter in the second lens group LG2 may be the lens closest to the first lens group LG1. Here, the size of the effective diameter is the average value of the effective diameter of the object side surface and the effective diameter of the sensor side surface of each lens. Therefore, the optical system 1000 can have good optical performance not only in the central part of the FOV but also in the peripheral part of the FOV, and can improve chromatic aberration and distortion aberration. The size of the lens with the smallest effective diameter in the first lens group LG1 may be smaller than the size of the lens with the smallest effective diameter in the second lens group LG2. The difference in effective diameter between the lenses with the smallest effective diameter in the first lens group LG1 and the second lens group LG2 may be less than 0.2 mm. Therefore, the incident light can be refracted to the effective area between the first lens group LG1 and the second lens group LG2, and then refracted to the peripheral part of the image sensor 300.

[0052] The lens closest to the object among the lenses of the first lens group LG1 may have a positive (+) refractive power, and the lens closest to the sensor among the lenses of the second lens group LG2 may have a negative (-) refractive power. In the optical system 1000, the number of lenses having a positive (+) refractive power may be equal to the number of lenses having a negative (-) refractive power. In the second lens group LG2, the number of lenses having a positive (+) refractive power may be greater than the number of lenses having a negative (-) refractive power. Two lenses facing each other in the region between the first lens group LG1 and the second lens group LG2 may have different refractive powers. Each of the plurality of lenses 100 may include an effective region and an ineffective region. The effective region may be a region through which light incident on each lens 100 passes. That is, the effective region may be an effective region or an effective diameter region that refracts the incident light to achieve optical characteristics. The ineffective region may be arranged around the effective region. The ineffective region may be a region in which effective light does not enter the plurality of lenses 100. That is, the ineffective region may be a region that is irrelevant to the optical characteristics. In addition, the end of the ineffective region may be a region fixed to a lens barrel (not shown) that houses the lens.

[0053] 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 passes through a plurality of lenses 100 in sequence. The image sensor 300 may include an element capable of detecting incident light, for example, a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The diagonal length of the image sensor 300 may be greater than 15 mm, for example, greater than 15 mm and less than 30 mm. Preferably, the ImgH of the image sensor 300 may be greater than TTL. The optical system 1000 may include an optical filter 500. The optical filter 500 may be disposed between the second lens group LG2 and the image sensor 300. The optical filter 500 may be disposed between the image sensor 300 and the lens closest to the sensor among the plurality of lenses 100. For example, when the optical system 1000 is an eight-element lens, the optical filter 500 may be disposed between the eighth lens 108 and the image sensor 300. The optical filter 500 may include an infrared filter. The optical filter 500 can transmit light of a set wavelength band and filter light of a different wavelength band. When the optical filter 500 includes an infrared filter, it can prevent radiant heat emitted from external light from being transferred to the image sensor 300. In addition, the optical filter 500 can transmit visible light and reflect infrared rays. As another example, a cover glass can also be provided between the optical filter 500 and the image sensor 300.

[0054] The optical system 1000 according to an embodiment may include an aperture stop ST. The aperture stop ST may be a stopper that adjusts the amount of light incident on the optical system 1000. The aperture stop ST may be disposed around at least one lens in the first lens group LG1. For example, the aperture stop ST may be disposed around the object-side surface or the sensor-side surface of the second lens 102. The aperture stop ST may be disposed between two adjacent lenses 101 and 102 in the lenses of the first lens group LG1. Alternatively, at least one lens selected from the plurality of lenses 100 may be used as the aperture stop. Specifically, the object-side surface or the sensor-side surface of one lens selected from the lenses of the first lens group LG1 may be used as the aperture stop to adjust the amount of light. The straight-line distance from the aperture stop ST to the sensor-side surface of the nth lens may be less than the optical axis distance from the object-side surface of the first lens 101 to the sensor-side surface of the nth lens. When the optical axis distance from the aperture stop ST to the sensor-side surface of the nth member is SD, the following condition may be satisfied: SD < ImgH. In addition, the following condition may be satisfied: SD < TTL. EFL is the effective focal length of the entire optical system and may be defined as F. EFL and ImgH may be the same or different from each other, and may have a difference of 2 mm or less. The FOV of the optical system 1000 may be less than 120 degrees, for example, greater than 70 degrees and less than 100 degrees. The F-number F# of the optical system 1000 may be greater than 1 and less than 10, for example, 1.1 ≤ F# ≤ 5. In addition, F# may be less than the entrance pupil diameter EPD. Therefore, the optical system 1000 has a thin size, can control the incident light, and can have improved optical characteristics within the field of view.

[0055] The effective diameter of the lens gradually decreases from the object-side lens to the lens surface between the first lens group LG1 and the second lens group LG2, and may gradually increase from the lens surface between the first lens group LG1 and the second lens group LG2 to the lens surface of the last lens. The optical system 1000 according to an embodiment may further include a reflecting member (not shown) for changing the optical path. The reflecting member may be implemented as a prism that reflects the incident light from the first lens group LG1 in the direction of the lens. Hereinafter, the optical system according to an embodiment will be described in detail.

[0056] Referring to Figure 1 and Figure 2, the optical system 1000 according to the first embodiment includes a lens 100, wherein the lens 100 may include a first lens 101 to an eighth lens 108 arranged in sequence along the optical axis OA. Light corresponding to object information may penetrate the first lens 101 to the eighth lens 108 and the filter 500 and be incident on the image sensor 300. The first lens group LG1 may include a first lens 101 and a second lens 102, and the second lens group LG2 may include a third lens 103 to an eighth lens 108. The optical axis distance between the second lens 102 and the third lens 103 may be a distance on the optical axis between the first lens group LG1 and the second lens group LG2. In the first lens 101 to the eighth lens 108, the number of lenses having a meniscus shape protruding from the optical axis toward the object may be 5 or more, and may satisfy, for example, n-2. n is the total number of lenses, and may be, for example, 8.

[0057] The first lens 101 may have a negative (-) refractive power and a positive (+) refractive power on the optical axis OA, and may preferably have a positive (+) refractive power. The first lens 101 may include plastic or glass. For example, the first lens 101 may be made of plastic. The first lens 101 may include a first surface S1 on the object side and a second surface S2 on the sensor side. 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 bulges toward the object on the optical axis OA. At least one of the first surface S1 and the second surface S2 may be an aspherical surface. 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, L1S1 is the first surface, and L1S2 is the second surface.

[0058] The second lens 102 may have a positive (+) refractive power or a negative (-) refractive power on the optical axis OA. The second lens 102 may have a negative refractive power. The second lens 102 may include plastic or glass. For example, the second lens 102 may be made of plastic. The second lens 102 may include a third surface S3 on the object side and a fourth surface S4 on the sensor side. 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 that bulges toward the object on the optical axis OA. Differently, on the optical axis OA, the third surface S3 may have a convex shape, and the fourth surface S4 may have a convex shape. At least one of the third surface S3 and the fourth surface S4 may be an aspherical surface. The aspherical coefficients of the third surface S3 and the fourth surface S4 are as follows Figure 4 The arrangement shown, where L2 is the second lens 102, L2S1 is the third surface, and L2S2 is the fourth surface.

[0059] The third lens 103 may have a positive (+) refractive power or a negative (-) refractive power on the optical axis OA, and may preferably have a positive (+) 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 on the object side and a sixth surface S6 on the sensor side. On the optical axis OA, the fifth surface S5 may have a concave shape, and the sixth surface S6 may have a convex shape. That is, the third lens 103 may have a meniscus shape that bulges toward the sensor on the optical axis OA. Differently, on the optical axis OA, the fifth surface S5 may have a concave shape, and the sixth surface S6 may have a concave shape. Alternatively, the third lens 103 may have a meniscus shape that bulges toward the object. At least one of the fifth surface S5 and the sixth surface S6 may be an aspherical surface. The aspherical coefficients of the fifth surface S5 and the sixth surface S6 are as follows Figure 4 The arrangement shown, wherein L3 is the third lens 103, L3S1 is the fifth surface, and L3S2 is the sixth surface.

[0060] The fourth lens 104 may have a positive (+) refractive power or a negative (-) refractive power on the optical axis OA. The fourth lens 104 may have a negative refractive power. The fourth lens 104 may include plastic or glass. For example, the fourth lens 104 may be made of plastic. When expressed as an absolute value, the focal length of the fourth lens 104 may be greater than the focal length of the seventh lens 107, and may satisfy, for example, the condition: 100<|F4|-|F7|<300. Here, the following condition may be satisfied: 200<|F4|<400. Among the lenses, the fourth lens 104 may have the largest focal length. The fourth lens 104 may include a seventh surface S7 on the object side and an eighth surface S8 on the sensor side. On the optical axis OA, the seventh surface S7 may have a convex shape, and the eighth surface S8 may have a concave shape. That is, the fourth lens 104 may have a meniscus shape that is convex toward the object on the optical axis OA. Alternatively, the fourth lens 104 may have a shape in which both surfaces are concave on the optical axis. Alternatively, the fourth lens 104 may have a meniscus shape that is convex toward the sensor on the optical axis OA. At least one or both of the seventh surface S7 and the eighth surface S8 of the fourth lens 104 may have a critical point. At least one of the seventh surface S7 and the eighth surface S8 may be an aspherical surface, and the aspherical coefficient is as follows: Figure 4 The arrangement shown, where L4 is the fourth lens 104, L4S1 is the seventh surface, and L4S2 is the eighth surface.

[0061] The fifth lens 105 may have a positive (+) refractive power or a negative (-) refractive power on the optical axis OA. The fifth lens 105 may have a positive (+) refractive power. The fifth lens 105 may include plastic or glass. For example, the fifth lens 105 may be made of plastic. The fifth lens 105 may include a ninth surface S9 on the object side and a tenth surface S10 on the sensor side. On the optical axis OA, the ninth surface S9 may have a convex shape, and the tenth surface S10 may have a concave shape. That is, the fifth lens 105 may have a meniscus convex toward the object on the optical axis OA. Alternatively, the fifth lens 105 may have a shape in which both surfaces are concave on the optical axis. Alternatively, the fifth lens 105 may have a meniscus convex toward the sensor on the optical axis OA. At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 105 may have a critical point. At least one of the ninth surface S9 and the tenth surface S10 may be an aspherical surface, and the aspherical coefficients of the ninth surface S9 and the tenth surface S10 are as follows: Figure 4 As shown in the arrangement, L5 is the fifth lens 105, L5S1 is the ninth surface, and L5S2 is the tenth surface.

[0062] The sixth lens 106 may have a positive (+) refractive power or a negative (-) refractive power on the optical axis OA. The sixth lens 106 may have a negative refractive power. The sixth lens 106 may include plastic or glass. The sixth lens 106 may be made of plastic. The sixth lens 106 may include an eleventh surface S11 on the object side and a twelfth surface S12 on the sensor side. On the optical axis OA, the eleventh surface S11 may have a concave shape, and the twelfth surface S12 may have a convex shape. That is, the sixth lens 106 may have a meniscus convex toward the sensor on the optical axis OA. Alternatively, the sixth lens 106 may have a meniscus convex toward the object. Alternatively, the sixth lens 106 may have a shape with concave on both sides or convex on both sides. At least one or both of the eleventh surface S11 and the twelfth surface S12 of the sixth lens 106 may be set to have no critical point. At least one of the eleventh surface S11 and the twelfth surface S12 may be an aspherical surface, and the aspherical coefficients of the eleventh surface S11 and the twelfth surface S12 are as follows: Figure 4 As shown in the arrangement, L6 is the sixth lens 106, L6S1 is the eleventh surface, and L6S2 is the twelfth surface.

[0063] The seventh lens 107 may have a positive (+) refractive power or a negative (-) refractive power on the optical axis OA. The seventh lens 107 may have a positive (+) refractive power. The seventh lens 107 may include plastic or glass. The seventh lens 107 may be made of plastic. The seventh lens 107 may include a thirteenth surface S13 on the object side and a fourteenth surface S14 on the sensor side. The thirteenth surface S13 may have a convex shape on the optical axis, and the fourteenth surface S14 may have a concave shape on the optical axis OA. That is, the seventh lens 107 may have a meniscus convex toward the object on the optical axis OA. Alternatively, the seventh lens 107 may have a meniscus convex toward the sensor. Alternatively, the seventh lens 107 may have a shape that is concave on both sides or convex on both sides on the optical axis OA. At least one or both of the thirteenth surface S13 and the fourteenth surface S14 of the seventh lens 107 may have a critical point. At least one of the thirteenth surface S13 and the fourteenth surface S14 may be an aspherical surface. For example, both the thirteenth surface S13 and the fourteenth surface S14 may be aspherical surfaces, and the aspherical coefficients may be as follows: Figure 4 In the arrangement shown, L7 is the seventh lens 107, L7S1 is the thirteenth surface, and L7S2 is the fourteenth surface.

[0064] The eighth lens 108 may have a negative refractive power on the optical axis OA. The eighth lens 108 may include plastic or glass. For example, the eighth lens 108 may be made of plastic. The eighth lens 108 may be a lens that is closest to the sensor or a lens of the last n-th lens in the optical system 1000. The eighth lens 108 may include a fifteenth surface S15 on the object side and a sixteenth surface S16 on the sensor side. On the optical axis OA, the fifteenth surface S15 may have a convex shape, and the sixteenth surface S16 may have a concave shape. That is, the eighth lens 108 may have a meniscus shape that protrudes toward the object on the optical axis OA. Alternatively, the eighth lens 108 may have a meniscus shape that protrudes from the optical axis toward the sensor or a shape that is concave on both sides. At least one or both of the fifteenth surface S15 and the sixteenth surface S16 of the eighth lens 108 may have a critical point. The fifteenth surface S15 and the sixteenth surface S16 may be aspherical surfaces, and the aspherical coefficients may be as Figure 4 In the arrangement shown, L8 is the eighth lens 108, L8S1 is the fifteenth surface, and L8S2 is the sixteenth surface.

[0065] like Figure 2As shown, each of the thirteenth surface S13 and the fortieth surface S14 of the seventh lens 107 may have at least one critical point P1 and P2 from the optical axis OA to the end of the effective region. Each of the fifteenth surface S15 and the sixteenth surface S16 of the eighth lens 108 may have at least one critical point P3 and P4 from the optical axis OA to the end of the effective region. The critical point is a point where the sign of the tilt value with respect 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 where the slope value is 0. Additionally, the critical point may be a point where the slope value decreases as it increases or a point where the slope value decreases and then increases.

[0066] The distances from the critical points of the thirteenth surface S13, the fourteenth surface S14, the fifteenth surface S15, and the sixteenth surface S16 may be defined as follows.

[0067] Inf71: The straight-line distance from the optical axis of the thirteenth surface S13 to the first critical point P1.

[0068] Inf72: The straight-line distance from the optical axis of the fourteenth surface S14 to the second critical point P2.

[0069] Inf81: The straight-line distance from the optical axis of the fifteenth surface S15 to the third critical point P3.

[0070] Inf82: The straight-line distance from the optical axis of the sixteenth surface S16 to the fourth critical point P4.

[0071] The distances from the optical axis to the respective critical points may satisfy the following conditions. Inf71 < Inf72 and Inf81 < Inf82 < Inf71.

[0072] The effective radii of the thirteenth surface S13, the fourteenth surface S14, the fifteenth surface S15, and the sixteenth surface S16 may be defined as r71, r72, r81, and r82 respectively, and the distances Inf71, Inf72, inf81, and inf82 from the optical axis to the critical points P1, P2, P3, and P4 may satisfy at least one of the following conditions.

[0073] 0.42 < Inf71 / r71 < 0.50, 0.48 < Inf72 / r72 < 0.56, 0.10 < Inf81 / r81 < 0.22, and 0.32 < Inf82 / r82 < 0.44

[0074] The positions of the first critical point P1, the second critical point P2, and the fourth critical point P4 may be more than 2 mm from the optical axis OA, for example, in the range of 2 mm to 4.2 mm, and the position of the third critical point P3 may be less than 2 mm from the optical axis OA, for example, in the range of 0.5 mm to 1.9 mm. The position of the third critical point P3 may be closer to the optical axis OA than the second critical point P2, and the position of the third critical point P3 may be closer to the optical axis OA than the fourth critical point P4 and the first critical point P1. Therefore, the seventh lens 107 may refract the incident light to the peripheral portion, and the eighth lens 108 may refract the incident light to the peripheral portion of the image sensor 300.

[0075] Preferably, the positions of the critical points of the seventh lens 107 and the eighth lens 108 satisfy the above range in consideration of the optical characteristics of the optical system 1000. Specifically, it is desirable that the positions of the critical points satisfy the above range for controlling the optical characteristics of the optical system 1000, such as chromatic aberration, distortion characteristics, aberration characteristics, and resolution. 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 first embodiment can have improved optical characteristics even in the center and peripheral portions of the FOV.

[0076] In addition, a normal line K2 which is a straight line perpendicular to a tangent line K1 passing through an arbitrary point of the sensor-side sixteenth surface S16 of the eighth lens 108 may have a maximum first angle θ1 with respect to the optical axis OA, and the first angle θ1 may be greater than 5 degrees and less than 65 degrees, for example, in the range of 20 to 50 degrees or 20 to 40 degrees. Therefore, based on a straight line perpendicular to the optical axis of the sixteenth surface S16, the concave value may be small, thereby providing a thin optical system. Here, a normal line perpendicular to a tangent line passing through a fifteenth surface S15 of the eighth lens 108 may have a maximum second angle θ2 with the optical axis, and a normal line perpendicular to a tangent line passing through a fourteenth surface S14 of the seventh lens 107 may have a maximum third angle θ3 with the optical axis, and a normal line perpendicular to a tangent line passing through a thirteenth surface S13 of the seventh lens 107 may have a maximum fourth angle θ4 with the optical axis. These angles may have the following relationship.

[0077] Condition: θ1<θ2 is satisfied, and θ1 and θ2 may be 50 degrees or less, for example, in the range of 20 to 50 degrees. Condition: θ2<θ3<θ4 is satisfied, and θ3 and θ4 may be 35 degrees or less, for example, in the range of 35 to 70 degrees.

[0078] On the optical axis, the radii of curvature of the first surface S1 and the second surface S2 of the first lens 101 are L1R1 and L1R2, the radii of curvature of the fifth surface S5 and the sixth surface S6 of the third lens 103 are L3R1 and L3R2, the radii of curvature of the seventh surface S7 and the eighth surface S8 of the fourth lens 104 are L4R1 and L4R2, the radii of curvature of the ninth surface S9 and the tenth surface S10 of the fifth lens 105 are L5R1 and L5R2, the radii of curvature of the eleventh surface S11 and the twelfth surface S12 of the sixth lens 106 are L6R1 and L6R2, the radii of curvature of the thirteenth surface S13 and the fourteenth surface S14 of the seventh lens 107 are L7R1 and L7R2, and the radii of curvature of the fifteenth surface S15 and the sixteenth surface S16 of the eighth lens 108 are L8R1 and L8R2. The radii of curvature can satisfy at least one of the following equations to improve the aberration characteristics of the optical system.

[0079] L2R1 * L2R2 < |L3R1| (Equation 1), L1R1 < L2R2 (Equation 2), L8R2 < L8R1 (Equation 3), L8R1 * L8R2 < |L6R1| (Equation 4), L8R1 + L8R2 < L4R2 (Equation 5), L7R1 + L7R2 < |L3R2| (Equation 6), L8R1 + L8R2 < L7R1 + L7R2 (Equation 7), |L6R1 * L6R2| < |L3R1 * L3R2| (Equation 8) and L5R1 + L5R2 < L4R1 + L4R2 (Equation 9)

[0080] On the optical axis, the radius of curvature of the eighteenth surface S18 of the eighth lens 108 can be the smallest, and the radius of curvature (absolute value) of the fifth surface S5 of the third lens 103 can be the largest. By setting such radii of curvature, good optical performance can be provided at the focal lengths of the respective lenses.

[0081] The effective diameter of the eighth lens 108 may have a maximum effective diameter of more than 15 mm. The effective diameter of the eighth lens 108 is the average of the effective diameters of the object-side surface and the sensor-side surface. The effective diameter of the eighth lens 108 may be greater than twice the radius of curvature (absolute value) of the twelfth surface S112. The effective diameters of the first surface S1 and the second surface S2 of the first lens 101 are CA_L1S1 and CA_L1S2, the effective diameters of the third surface S3 and the fourth surface S4 of the second lens 102 are CA_L2S1 and CA_L2S2, the effective diameters of the fifth surface S5 and the sixth surface S6 of the third lens 103 are CA_L3S1 and CA_L3S2, the effective diameters of the seventh surface S7 and the eighth surface S8 of the fourth lens 104 are CA_L4S1 and CA_L4S2, the effective diameters of the ninth surface S9 and the tenth surface S10 of the fifth lens 105 are CA_L5S1 and CA_L5S2, the effective diameters of the eleventh surface S11 and the twelfth surface S12 of the sixth lens 106 are CA_L6S1 and CA_L6S2, the effective diameters of the thirteenth surface S13 and the fourteenth surface S14 of the seventh lens 107 are CA_L7S1 and CA_L7S2, and the effective diameters of the fifteenth surface S15 and the sixteenth surface S16 of the eighth lens 108 are CA_L8S1 and CA_L8S2. These effective diameters are factors affecting the aberration characteristics of the optical system and may satisfy at least one of the following equations.

[0082] CA_L2S2 < CA_L2S1 < CA_L1S1 (Equation 1)

[0083] CA_L5S1 < CA_L5S2 < CA_L6S1 < CA_L6S2 (Equation 2)

[0084] CA_L6S2 < CA_L7S1 < CA_L7S2 < CA_L8S1 < CA_L8S2 (Equation 3)

[0085] CA_L2S1 - CA_L3S1 < CA_L1S1 - CA_L1S2 (Equation 4)

[0086] CA_L5S1 + CA_L5S2 < CA_L8S2 (Equation 5)

[0087] L8R1 + L8R2 < CA_L8S2 (Equation 6)

[0088] Among the first to eighth lenses 101 to 108, the average effective diameter of the lenses may be the smallest for the second lens 102, and may be the largest for the eighth lens 108. The effective diameter of the fourth surface S4 or the fifth surface S5 may be the smallest, and the effective diameter of the sixteenth surface S16 may be the largest. The effective diameter of the eighth lens 108 is the largest, so that it can effectively refract incident light toward 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 incident light.

[0089] In the optical system, the number of lenses having a refractive index exceeding 1.6 may be 2 or less, and may be less than the number of lenses having a refractive index less than 1.6. The average refractive index of the first to eighth lenses 101 to 108 may be less than 1.6. In the optical system, the number of lenses having an Abbe number greater than 45 may be greater than the number of lenses having an Abbe number less than 45. The average Abbe number of the first to eighth lenses 101 to 108 may be greater than 45.

[0090] The back focal length is the optical axis distance from the image sensor 300 to the last lens. That is, BFL is the optical axis distance between the image sensor 300 and the sixteenth sensor-side surface of the eighth lens 108. CT7 is the center thickness or optical axis thickness of the seventh lens 107, and L7_ET is the end thickness or edge thickness of the effective area of ​​the seventh lens 107. CT8 is the center thickness or optical axis thickness of the eighth lens 108. CG7 is the optical axis distance (i.e., center distance) from the center of the sensor-side surface of the seventh lens 107 to the center of the object-side surface of the eighth lens 108. That is, the optical axis distance CG7 from the center of the sensor-side surface of the seventh lens 107 to the center of the object-side surface of the eighth lens 108 is the distance between the fourteenth surface S14 and the fifteenth surface S15 on the optical axis OA. CG7 may be greater than the optical axis distance between the third lens 103 and the fourth lens 104. CG7 may be less than the sum of the center thicknesses of the seventh lens 107 and the eighth lens 108.

[0091] Among the first lens 101 to the eighth lens 108, the lens with the largest center thickness is the seventh lens 107. The center thickness CT7 of the seventh lens 107 can be greater than the optical axis distance between the sixth lens 106 and the seventh lens 107 and less than the optical axis distance CG7 between the seventh lens 107 and the eighth lens 108. The lens with the smallest center thickness can be the second lens 102. Thus, the optical system 1000 can control incident light and has improved aberration characteristics and resolution. The center distance CG7 between the seventh lens 107 and the eighth lens 108 is the largest among the distances between the lenses, and the optical axis distance between the third lens 103 and the fourth lens 104 is the smallest among the distances between the lenses. Among the lenses 101 to 108, the largest center thickness can be 2.5 times or more, for example, 2.5 times to 5 times the smallest center thickness. Among the lenses, the number of lenses with a center thickness less than 0.5 mm can be less than the number of lenses with a center thickness of 0.5 mm or more, and can be 2 or less. The average center thickness of the lenses can be greater than 0.6 mm. The optical system 1000 having an image sensor 300 with a size of about 1 inch can be provided in a structure with a thin thickness.

[0092] When the focal lengths of the respective lenses 101 to 108 are defined as F1 to F8, the following conditions can be satisfied: F2 < F4 and F1 < F3. Additionally, the following conditions can be satisfied: F8 < F7 < F4. By adjusting such focal lengths, the resolution can be affected. When the focal lengths are described as absolute values, the focal length of the fourth lens 104 can be the largest among the lenses, and the focal length of the eighth lens 108 can be the smallest, and the difference between the focal lengths of the first lens 101 and the eighth lens 108 can be 10 mm or less. The largest focal length can be 20 times or more the smallest focal length. When the refractive indices of the respective lenses 101 to 108 are n1 to n8 and the Abbe numbers of the respective lenses 101 to 108 are v1 to v8, the refractive indices can satisfy the conditions: n1 < n2 and n1, n3, n4, n5, n6, n7, and n8 are less than 1.6, and the differences between them can be less than 0.3, and n2 is greater than 1.6 and can be the largest among the refractive indices of the lenses. The Abbe numbers can satisfy the conditions: v2 < v1 and v1, v3, v4, v5, v6, v7, and v8 can be 45 or more, and the differences between them are 10 or less, and v2 can be less than 45, for example, 30 or less. Thus, the optical system 1000 can have improved chromatic aberration control characteristics.

[0093] The optical system 1000 according to the first embodiment described above may satisfy at least one or two of the equations described below. Therefore, the optical system 1000 according to the first embodiment may have improved optical characteristics. For example, when the optical system 1000 satisfies at least one equation, 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 portion of the FOV but also in the peripheral portion. The optical system 1000 may have improved resolution and may have a thinner and more compact structure. Hereinafter, the center thickness of the first lens 101 to the eighth lens 108 may be defined as CT1 to CT8, and the edge thickness may be defined as ET1 to ET8, and the optical axis distance between two adjacent lenses may be defined as CG1 to CG8 from the distance between the first lens and the second lens to the distance between the seventh lens and the eighth lens, and the edge distance between two adjacent lenses may be defined as EG1 to EG8 from the distance between the first lens and the second lens to the distance between the seventh lens and the eighth lens. The units of thickness and distance are mm.

[0094] [Formula 1] <CT1 / CT2<4

[0095] In Formula 1, when 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 are satisfied, the optical system 1000 can improve aberration characteristics. Preferably, Formula 1 can satisfy: 2≤CT1 / CT2<3.

[0096] [Formula 2]1 <CT3 / ET3<3

[0097] In Formula 2, when the thickness CT3 of the third lens 103 on the optical axis and the thickness ET3 of the fourth lens 104 at the edge of the effective area are satisfied, the optical system 1000 may have improved chromatic aberration control characteristics. Preferably, Formula 2 may satisfy: 1.5 <CT3 / ET3≤2.5。

[0098] [Formula 2-1]2 <CT1 / ET1<3.5

[0099] [Formula 2-2]0 <CT2 / ET2<1

[0100] [Formula 2-3] (CT2+CT3)>CT1

[0101] [Formula 2-4]1 <CT4 / ET4<3

[0102] [Formula 2-5]1 <CT5 / ET5<3

[0103] [Formula 2-6]1 <CT6 / ET6<2.5

[0104] [Formula 2-7]0 <CT7 / ET7<1.2

[0105] [Formula 2-8]0 <CT8 / ET8<1

[0106] [Formula 2-9] 0.5 <SD / TD<1

[0107] When the ratio between the center thickness and the edge thickness of the second lens 102 to the eighth lens 108 satisfies Formulas 2-1 to 2-8, the optical system 1000 can have improved chromatic aberration control characteristics. SD is the optical axis distance from the aperture stop to the sensor-side sixteenth surface S16 of the eighth lens 108, and TD is the optical axis distance from the object-side first surface S1 of the first lens 101 to the sensor-side sixteenth surface S16 of the eighth lens 108. The aperture stop can be provided around the object-side surface of the second lens 102. When the optical system 1000 according to the first embodiment satisfies Formula 2-9, the chromatic aberration of the optical system 1000 can be improved.

[0108] [Formula 2-10]1 <F_LG2 / F_LG1<3

[0109] 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 first embodiment satisfies Formula 2-10, the chromatic aberration of the optical system 1000 can be improved. That is, when the value of Formula 2-10 is close to 1, the distortion aberration can be reduced. The value of Formula 2-10 can satisfy: 1 <F_LG2 / F_LG1<2。

[0110] [Formula 3]1 <ET8 / CT8<3

[0111] In Formula 3, when the thickness CT8 on the optical axis and the thickness (ET8) at the edge of the eighth lens 108 are satisfied, the optical system 1000 may have improved chromatic aberration control characteristics. Formula 3 may satisfy: 2≤ET8 / CT8<3. In addition, the condition CT6+CT8 may be satisfied. <ET8。

[0112] [Equation 4] 1.6 <n2

[0113] In Formula 4, n2 represents a refractive index at the d-line of the second lens 102. When the optical system 1000 according to the first embodiment satisfies Formula 4, the optical system 1000 can improve chromatic aberration characteristics.

[0114] [Formula 4-1] 1.50 <n1<1.60,1.50<n8<1.60

[0115] In Equation 4-1, n1 is the refractive index at the d-line of the first lens 101, and n8 is the refractive index at the d-line of the eighth lens 108. When the optical system 1000 according to the first embodiment satisfies Equation 4-1, the influence on the TTL of the optical system 1000 can be suppressed.

[0116] [Equation 4-2] 1.50 < n4 < 1.60

[0117] 1.50 < n4 < 1.60

[0118] In Equation 4-2, n4 represents the refractive index at the d-line of the fourth lens 104, and n6 represents the refractive index at the d-line of the sixth lens 106. When the optical system 1000 according to the first embodiment satisfies Equation 4-2, the optical system 1000 can improve the chromatic aberration characteristics.

[0119] [Equation 5] 1 < L8S2_Max_Sag to sensor < 2

[0120] In Equation 5, L8S2_Max_Sag (L8S2_Max indentation) to sensor represents the distance in the optical axis direction from the maximum indentation value of the sixteenth surface S16 on the sensor side of the eighth lens 108 to the image sensor 300. For example, L8S2_Max_Sag to sensor represents the distance in the optical axis direction from the critical point P2 on the sensor side surface of the eighth lens 108 to the image sensor 300. When the optical system 1000 according to the first embodiment satisfies Equation 5, the optical system 1000 ensures that the filter 500 can be placed between the lens unit 100 and the image sensor 300, thus having improved assembly performance. In addition, when the optical system 1000 satisfies Equation 5, the optical system 1000 can ensure the distance for module manufacturing. Preferably, the value of Equation 5 can satisfy: 1.3 < L8S2_Max_Sag to sensor < 1.8.

[0121] In the lens data of the first embodiment, the position of the filter 500, the specific distance between the last lens and the filter 500, and the distance between the image sensor 300 and the filter 500 are positions set for the convenience of designing the optical system 1000, and the filter 500 can be freely arranged within the range where it does not contact the last lens and the image sensor 300. Therefore, the value of L8S2_Max_Sag to sensor in the lens data can be less than the BFL (back focal length) of the optical system 1000, and the position of the filter 500 can be moved within the range where it does not contact the last lens and the image sensor 300 respectively, so that good optical performance can be achieved. That is, on the sixteenth surface S16 of the eighth lens 108, the distance between the critical point P2 and the image sensor 300 is the smallest, and it can gradually increase towards the end of the effective area.

[0122] [Equation 6] 1 < BFL / L8S2_Max_Sag to sensor < 2

[0123] In Equation 6, the back focal length (BFL) represents the distance (mm) on the optical axis OA from the center of the sixteenth surface S16 on the sensor side of the eighth lens 108 closest to the image sensor 300 to the imaging surface of the image sensor 300. When the optical system 1000 according to the first embodiment satisfies Equation 6, the optical system 1000 can improve the distortion aberration characteristics and has good optical performance in the peripheral region of the FOV. Here, the maximum indentation value can be the critical point position. Equation 6 can be satisfied: 1 ≤ BFL / L8S2_Max_Sag to sensor < 1.5.

[0124] [Equation 7] 5 < |L8S2_Max slope| < 65

[0125] In Equation 7, L8S2_Max slope represents the maximum value (degrees) of the tangent angle measured on the sixteenth surface S16 on the sensor side of the eighth lens 108. Specifically, the L8S2_Max slope in the sixteenth surface S16 represents the angular value (degrees) of the point having the maximum tangent angle with respect to an imaginary line extending in a direction perpendicular to the optical axis OA. When the optical system 1000 according to the first embodiment satisfies Equation 7, the optical system 1000 can control the occurrence of lens flare. Preferably, Equation 7 can be satisfied: 20 ≤ |L8S2_Max slope| ≤ 50.

[0126] [Equation 8] 1 < Inf81 < 1.5

[0127] In Equation 8, Inf81 can represent the distance from the optical axis OA to the critical point (or inflection point) of the fifteenth surface S15 on the object side of the eighth lens 108. Inf81 can be located within 1.2 mm ± 0.2 mm from the optical axis OA. When the optical system 1000 according to the first embodiment satisfies Equation 8, the influence on the thinness ratio of the optical system 1000 can be suppressed.

[0128] [Equation 9] 1 < CG7 / G7_Min < 15

[0129] Equation 9 represents the minimum distance between the seventh lens 107 and the eighth lens 108 and the distance CG7 between the seventh lens 107 and the eighth lens 108 based on the optical axis OA. When the optical system 1000 according to the first embodiment satisfies Equation 9, the optical system 1000 can improve the distortion aberration characteristics and has good optical performance in the peripheral part of the FOV. Equation 9 can be satisfied: 3 < CG7 / G7_Min < 12 or 3 < CG7 / G7_Min ≤ 8

[0130] [Equation 10] 1 < CG7 / EG7 < 5

[0131] In Formula 10, when the optical axis distance CG7 between the seventh lens 107 and the eighth lens 108 and the optical axis distance EG8 at the end of the effective area between the seventh lens 107 and the eighth lens 108 are satisfied, good optical performance can be obtained at the center and the periphery of the FOV. In addition, the optical system 1000 can reduce distortion and have improved optical performance. Preferably, Formula 10 can satisfy:

[0132] 3 <CG7 / EG7<4。

[0133] [Equation 11] 0.01 <CG1 / CG6<1

[0134] In Formula 11, when the optical axis distance CG1 between the first lens 101 and the second lens 102 and the optical axis distance CG6 between the sixth lens 106 and the seventh lens 107 are satisfied, the optical system 1000 can improve aberration characteristics and control the size of the optical system 1000, for example, reduce TTL. Preferably, Formula 11 can satisfy:

[0135] 0.4 <CG1 / CG6<0.9。

[0136] [Formula 11-1]3 <CA_L8S2 / CG7<20

[0137] In Formula 11-1, CA_L8S2 is the effective diameter of the maximum lens surface, and is the effective diameter of the sensor-side sixteenth surface S16 of the eighth lens 108. When the optical system 1000 according to the first embodiment satisfies Formula 11-1, the optical system 1000 can improve aberration characteristics and control TTL reduction. Preferably, Formula 11-1 can satisfy:

[0138] 5 <CA_L8S2 / CG7<10。

[0139] [Formula 11-2]3 <CA_L7S2 / CG7<15

[0140] Formula 11-2 can set the effective diameter CA_L7S2 of the sensor-side fourteenth surface S14 of the seventh lens 107 and the optical axis distance between the seventh lens 107 and the eighth lens 108. When the optical system 1000 according to the first embodiment satisfies Formula 11-2, the optical system 1000 can improve the aberration characteristics and control TTL reduction. Preferably, Formula 11-2 can satisfy:

[0141] 5 <CA_L7S2 / CG7<9。

[0142] [Equation 12] <CT1 / CT7<2

[0143] In Equation 12, when the thickness CT1 of the first lens 101 on the optical axis OA and the thickness CT7 of the seventh lens 107 on the optical axis OA are satisfied, the optical system 1000 can have improved aberration characteristics. In addition, the optical system 1000 has good optical performance at the set FOV and can control the TTL.

[0144] Preferably, Equation 12 can satisfy:

[0145] 0.5 < CT1 / CT7 < 1.

[0146] [Equation 13] 0 < CT6 / CT7 < 3

[0147] In Equation 13, when the thickness CT6 of the sixth lens 106 on the optical axis OA and the thickness CT7 of the seventh lens 107 on the optical axis are satisfied, the optical system 1000 can alleviate the manufacturing precision of the sixth lens 106 and the seventh lens 107, and can improve the optical performance of the central part and the peripheral part of the FOV. Preferably, Equation 13 can satisfy: 0 < CT6 / CT7 < 1. The central thicknesses of the fifth lens, the sixth lens, and the seventh lens can satisfy the following condition: CT7 < (CT5 + CT6) < CT7 * 2. In addition, the central thicknesses of the first lens, the sixth lens, the seventh lens, and the eighth lens can satisfy the condition: CT6 < CT1 < CT7.

[0148] [Equation 14] 0 < L7R2 / L8R1 < 2

[0149] In Equation 14, L7R2 represents the radius of curvature (mm) on the optical axis of the fourteenth surface S14 of the seventh lens 107, and L8R1 represents the radius of curvature (mm) on the optical axis of the fifteenth surface S15 of the eighth lens 108. When the optical system 1000 according to the first embodiment satisfies Equation 14, the aberration characteristics of the optical system 1000 can be improved. Preferably, Equation 14 can satisfy:

[0150] 0.5 < L7R2 / L8R1 < 1.

[0151] [Equation 15] 0 < (CG6 - EG6) / (CG6) < 2

[0152] If Formula 15 satisfies the center distance CG6 and the edge distance CG7 between the sixth lens 106 and the seventh lens 107, the optical system 1000 can reduce the occurrence of distortion and have improved optical performance. When the optical system 1000 according to the first embodiment satisfies Formula 15, the optical performance of the central part and the peripheral part of the FOV can be improved. Preferably, Formula 15 can satisfy: 0.5<(CG6-EG6) / (CG6)<1. Here, when the center distances CG between the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are compared, CG4 can be satisfied. <CG6<CG5<CG7。

[0153] [Formula 16]1 <CA_L1S1 / CA_L2S2<2

[0154] In Formula 16, CA_L1S1 represents an effective diameter (clear aperture, CA) of the first surface S1 of the first lens 101, and CA_L2S2 represents an effective diameter (CA) of the fourth surface S4 of the second lens 102. When the optical system 1000 according to the first embodiment satisfies Formula 16, the optical system 1000 can control light incident on the first lens group LG1 and has improved aberration control characteristics. Preferably, Formula 16 can satisfy: 1 <CA_L1S1 / CA_L2S2<1.5。

[0155] [Formula 17]1 <CA_L7S2 / CA_L3S1<5

[0156] In Formula 17, CA_L3S1 represents an effective diameter of the fifth surface S5 of the third lens 103, and CA_L7S2 represents an effective diameter of the fourteenth surface S14 of the seventh lens 107. When the optical system 1000 according to the first embodiment satisfies Formula 17, the optical system 1000 can control light incident on the second lens group LG2 and improve aberration characteristics. Preferably, Formula 17 can satisfy: <CA_L7S2 / CA_L3S1<3。

[0157] [Equation 18] 0.5 <CA_L2S2 / CA_L3S1<1.5

[0158] In Formula 18, when the effective diameter CA_L2S2 of the fourth surface S4 of the second lens 102 and the effective diameter CA_L3S1 of the fifth surface S5 of the third lens 103 are satisfied, the optical system 1000 can improve chromatic aberration and control vignetting of optical performance. Preferably, Formula 18 can satisfy: 0.7 <CA_L2S2 / CA_L3S1<1。

[0159] [Equation 19] 0.1 <CA_L5S2 / CA_L7S2<1

[0160] In Equation 19, when the effective diameter CA_L5S2 of the tenth surface S10 of the fifth lens 105 and the effective diameter CA_L7S2 of the fourteenth surface S14 of the seventh lens 107 are satisfied, the optical system 1000 can improve chromatic aberration. Preferably, Equation 19 can be satisfied: 0.4 ≤ CA_L5S2 / CA_L7S2 ≤ 0.7.

[0161] [Equation 20] 1 < CA_L8S2 / CA_L1S1 < 5

[0162] In Equation 20, when the effective diameter CA_L8S1 of the sixteenth surface S16 of the eighth lens 108 and the effective diameter CA_L1S1 of the first surface S1 of the first lens 101 are satisfied, the optical system 1000 can set the field of view and the size of the optical system. Preferably, Equation 20 can be satisfied: 2 < CA_L8S2 / CA_L1S1 < 3.5.

[0163] [Equation 21] 0.8 < CG3 / EG3 < 5

[0164] In Equation 21, when the distance CG3 between the third lens 103 and the fourth lens 104 on the optical axis OA and the edge distance EG3 of the third lens 103 and the fourth lens 104 are satisfied, the optical system 1000 can reduce chromatic aberration, improve aberration characteristics and control vignetting of the optical performance. Preferably, Equation 21 can be satisfied: 1 < CG3 / EG3 < 2.

[0165] [Equation 22] 1 < CG6 / EG6 < 5

[0166] In Equation 22, when the center distance CG7 and the edge distance EG7 between the seventh lens 107 and the eighth lens 108 are satisfied, even in the central part and the peripheral part of the FOV, the optical system can provide good optical performance. And the occurrence of distortion can be suppressed.

[0167] At least one of Equation 21 and Equation 22 may further include at least one of Equation 22-1 to Equation 22-6.

[0168] [Equation 22-1] 0 < CG1 / EG1 < 1 [Equation 22-2] 5 < CG2 / EG2 < 10

[0169] [Equation 22-3] 0 < CG4 / EG4 < 1.2 [Equation 22-4] 1 < CG5 / EG5 < 10

[0170] [Equation 22-5] 15 < (CG6 / EG6) * n < 25, where n is the total number of lenses

[0171] [Equation 22-6] 1 < CG8 / EG8 < 6

[0172] [Equation 23] <G7_Max / CG7<2

[0173] In Formula 23, G7_Max represents the maximum distance (mm) between the seventh lens 107 and the eighth lens 108. When the optical system 1000 according to the first embodiment satisfies Formula 23, the optical performance in the peripheral portion of the FOV can be improved, and the distortion of the aberration characteristics can be suppressed. Preferably, Formula 23 can satisfy: 0.5 <G7_Max / CG7<1.5。

[0174] [Equation 24] <CT6 / CG6<2

[0175] In Formula 24, the thickness CT6 of the sixth lens 106 on the optical axis OA and the distance CG6 between the sixth lens 106 and the seventh lens 107 on the optical axis OA are satisfied. In this case, the optical system 1000 can reduce the effective diameter size of the sixth lens and the seventh lens and the center distance between adjacent lenses, and improve the optical performance of the peripheral portion of the FOV. Preferably, Formula 24 can satisfy: <CT6 / CG6<1。

[0176] [Formula 25]1 <CT6 / CG5<3

[0177] In Formula 25, when the thickness CT6 of the sixth lens 106 on the optical axis OA and the distance CG5 between the fifth lens 105 and the sixth lens 106 are satisfied, the optical system 1000 can reduce the size and distance of the effective diameters of the fifth lens and the sixth lens, and can improve the optical performance of the peripheral portion of the FOV. Preferably, Formula 25 can satisfy: 1 <CT6 / CG5<2.3。

[0178] [Equation 26] 0.1 <CT7 / CG5<1

[0179] When the equation 26 satisfies the thickness CT7 of the seventh lens 107 on the optical axis OA and the distance CG5 between the fifth lens 105 and the sixth lens 106, the optical system 1000 can reduce the effective diameter size of the seventh lens and the center distance between the fifth lens and the sixth lens, and can improve the optical performance of the peripheral portion of the FOV. Preferably, the equation 26 can satisfy: 0.3 <CT7 / CG5<0.8。

[0180] [Equation 27] 1<|L5R2 / CT5|<50

[0181] When Equation 27 satisfies the radius of curvature L5R2 of the tenth surface S10 of the fifth lens 105 and the thickness CT5 on the optical axis of the fifth lens 105, the optical system 1000 can control the refractive power of the fifth lens 105 and improve the optical performance of the light incident on the second lens group LG2. Preferably, Equation 27 can be satisfied: 100 < |L5R2 / CT5| < 200. Additionally, the condition: L5R2 > 0 can be satisfied.

[0182] [Equation 28] 0 < L5R1 / L7R1 < 5

[0183] If Equation 28 satisfies the radius of curvature L5R1 of the ninth surface S9 of the fifth lens 105 and the radius of curvature L7R1 of the thirteenth surface S13 of the seventh lens 107, then the shapes and refractive powers of the fifth lens and the seventh lens can be controlled, the optical performance can be improved, and the optical performance of the second lens group LG2 can be improved. Preferably, Equation 28 can be satisfied: 0 < L5R1 / L7R1 < 1.

[0184] [Equation 29] 0 < L1R1 / L1R2 < 1

[0185] Equation 29 can set the radius of curvature L1R1 and L1R2 of the first surface S1 and the second surface S2 on the object side of the first lens 101, and when these conditions are satisfied, the lens size and resolution can be determined. Preferably, Equation 29 can be satisfied: 0 < L1R1 / L1R2 < 0.5. Preferably, L1R1 > 0 and L1R2 > 0 can be satisfied.

[0186] [Equation 30] 0 < L2R2 / L2R1 < 1

[0187] Equation 30 can set the radius of curvature L2R1 and L2R2 of the third surface S3 and the fourth surface S4 on the object side of the second lens 102, and when these conditions are satisfied, the resolution of the lens can be determined. Preferably, Equation 30 can be satisfied: 0 < L2R2 / L2R1 < 0.8. Preferably, L2R1 > 0 and L2R2 > 0 can be satisfied.

[0188] At least one of Equation 28, Equation 29, and Equation 30 can include the following Equation 30-1 to 30-6, and the resolution of each lens can be determined.

[0189] [Equation 30-1] 2 < L3R1 / L3R2 < 6 [Equation 30-2] 1 < L4R1 / L4R2 < 3

[0190] [Equation 30-3] 0 < L5R1 / L5R2 < 1 [Equation 30-4] 3 < L6R1 / L6R2 < 10

[0191] [Equation 30-5] 0 < L7R1 / L7R2 < 1.5 [Equation 30-6] 1 < L8R2 / L8R1 < 4

[0192] Preferably, the conditions: L3R1 < 0, L3R2 < 0, L6R1 < 0, and L6R2 < 0 can be satisfied.

[0193] [Equation 31] 0 < CT_Max / CG_Max < 2

[0194] In Equation 31, when the maximum thickness CT_Max on the optical axis OA of each lens and the maximum value CG_Max of the air gap or distance on the optical axis between multiple lenses are satisfied, the optical system 1000 has good optical performance at the set FOV and focal length, and the size of the optical system 1000 can be reduced. For example, the TTL can be reduced. Preferably, Equation 31 can satisfy: 0 < CT_Max / CG_Max < 1.

[0195] [Equation 32] 0.5 < ΣCT / ΣCG < 2

[0196] In Equation 32, ΣCT represents the sum of the thicknesses (mm) on the optical axis OA of each of the multiple lenses, and ΣCG represents the sum of the distances (mm) on the optical axis OA between two adjacent lenses among the multiple lenses. When the optical system 1000 according to the first embodiment satisfies Equation 32, the optical system 1000 has good optical performance at the set FOV and focal length, and the size of the optical system 1000 can be reduced. For example, the TTL can be reduced. Preferably, Equation 32 can satisfy: 1 < ΣCT / ΣCG < 1.8.

[0197] [Equation 33] 10 < ∑Index < 30

[0198] In Equation 33, ∑Index represents the sum of the refractive indices at the d-line of each of the multiple lenses. When the optical system 1000 according to the first embodiment satisfies Equation 33, the TTL of the optical system 1000 can be controlled, and improved resolution can be achieved. Here, the average refractive index of the first lens 101 to the eighth lens 108 can be 1.50 or more. Preferably, Equation 33 can satisfy: 10 < ∑Index < 20.

[0199] [Equation 34] 10 < ∑Abb / ∑Index < 50

[0200] In Formula 34, ∑Abb represents the sum of the Abbe numbers of each of the plurality of lenses. When the optical system 1000 according to the first embodiment satisfies Formula 34, the optical system 1000 may have improved aberration characteristics and resolution. The average Abbe number of the first lens 101 to the eighth lens 108 may be greater than 45. Preferably, Formula 34 may satisfy: 20<∑Abb / ∑Index<40.

[0201] [Equation 35] 0<|Max_Distortion|<5

[0202] In Formula 35, Max_Distortion represents the maximum distortion value 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 first embodiment satisfies Formula 35, the optical system 1000 can improve the distortion characteristics. Preferably, Formula 35 can satisfy: 1<|Max_Distortion|<3

[0203] [Equation 36] <EG_Max / CT_Max<2

[0204] In Formula 36, ​​CT_Max represents the thickest thickness (mm) among the thicknesses on the optical axis OA of each of the plurality of lenses, and EG_Max is the maximum distance on the edge side between two adjacent lenses. When the optical system 1000 according to the first embodiment satisfies Formula 36, ​​the optical system 1000 has a set FOV and focal length, and can have good optical performance in the peripheral portion of the FOV. Preferably, Formula 36 can satisfy: <EG_Max / CT_Max<1。

[0205] [Equation 37] 0.5 <CA_L1S1 / CA_Min<2

[0206] In Formula 37, when the effective diameter CA_L1S1 of the first surface S1 of the first lens 101 and the minimum effective diameter CA_Min among the effective diameters of the first surface S1 to the sixteenth surface S16 are satisfied, light incident through the first lens 101 can be controlled, and a thin optical system can be provided while maintaining optical performance. Preferably, Formula 37 can satisfy: 1 <CA_L1S1 / CA_Min<1.5。

[0207] [Formula 38]1 <CA_Max / CA_Min<5

[0208] In Formula 38, CA_Max represents the maximum effective diameter among the object-side surface and the sensor-side surface of the plurality of lenses, and represents the maximum effective diameter among the effective diameters (mm) of the first surface S1 to the sixteenth surface S16. When the optical system 1000 according to the first embodiment satisfies Formula 38, the optical system 1000 can provide a thin and compact optical system while maintaining optical performance. Preferably, Formula 38 can satisfy: 2 <CA_Max / CA_Min<4。

[0209] [Formula 39]1 <CA_Max / CA_Aver<3

[0210] In Formula 39, the maximum effective diameter CA_Max and the average effective diameter CA_Aver are set between the object side surface and the sensor side surface of the plurality of lenses, and when these conditions are met, a thin and compact optical system can be provided. Preferably, Formula 39 may satisfy: 1.5 <CA_Max / CA_AVR<2.5。

[0211] [Equation 40] 0.1 <CA_Min / CA_Aver<1

[0212] In equation 40, a minimum effective diameter CA_Min and an average effective diameter CA_Aver can be set between the object side surface and the sensor side surface of the plurality of lenses, and when these conditions are met, a thin and compact optical system can be provided. Preferably, equation 40 can satisfy: 0.1 <CA_Min / CA_AVR≤0.8。

[0213] [Equation 41] 0.1 <CA_Max / (2×ImgH)<1

[0214] In Formula 41, the maximum effective diameter CA_Max between the object side surface and the sensor side surface of the plurality of lenses and the distance ImgH from the center (0.0F) to the diagonal end (1.0F) of the image sensor 300 can be set. When this condition is met, the optical system 1000 has good optical performance at the center and the periphery of the FOV, and a thin and compact optical system can be provided. Here, ImgH can be in the range of 4 mm to 15 mm. Preferably, Formula 41 can satisfy: 0.5≤CA_Max / (2*ImgH)<1.

[0215] [Equation 42] 0.1 <TD / CA_Max<1.5

[0216] In Equation 42, TD is the maximum optical axis distance (mm) from the object side of the first lens group LG1 to the sensor side of the second lens group LG2. For example, it is the distance on the optical axis OA from the first surface S1 of the first lens 101 to the sixteenth surface S16 of the eighth lens 108. When the optical system 1000 according to the first embodiment satisfies Equation 42, a thin and compact optical system can be provided. Preferably, Equation 42 can be satisfied: 0.5 < TD / CA_Max < 1.

[0217] [Equation 43] 0 < F / L7R2 < 5

[0218] In Equation 43, the total effective focal length F of the optical system 1000 and the radius of curvature L7R2 of the fourteenth surface S14 of the seventh lens 107 can be set. When these conditions are satisfied, the optical system 1000 can reduce the size of the optical system 1000, for example, reduce the TTL. Preferably, Equation 43 can be satisfied: 1 < F / L7R2 < 3. Equation 43 can further include the following Equation 43-1.

[0219] [Equation 43-1] 2 < F / F# < 8

[0220] F# can represent the F-number. Preferably, Equation 43-1 can be satisfied: 5 < F / F# < 7.5.

[0221] [Equation 43-2] 1 < F / L8R2 < 5

[0222] Equation 43-2 can set the total effective focal length F of the optical system 1000 and the radius of curvature L8R2 of the sixteenth surface S16 of the eighth lens 108. Preferably, Equation 43-2 can be satisfied: 2 < F / L8R2 < 4.

[0223] [Equation 44] 1 < F / L1R1 < 10

[0224] In Equation 44, the radius of curvature L1R1 of the first surface S1 of the first lens 101 and the total effective focal length F can be set, and when these conditions are satisfied, the size of the optical system 1000 can be reduced, for example, the TTL can be reduced. Preferably, Equation 44 can be satisfied: 1 < F / L1R1 < 5.

[0225] [Equation 45] 0 < EPD / L8R2 < 5

[0226] In Equation 45, EPD represents the size (mm) of the entrance pupil diameter of the optical system 1000, and L8R2 represents the radius of curvature (mm) of the sixteenth surface S16 of the eighth lens 108. When the optical system 1000 according to the first embodiment satisfies Equation 45, the optical system 1000 can control the total luminance and has good optical performance at the center and periphery of the FOV. Preferably, Equation 45 can be satisfied as: 0 < EPD / L8R2 < 1.

[0227] Equation 45 may further include the following Equation 45-1.

[0228] [Equation 45-1] 1 < EPD / F# < 3

[0229] [Equation 46] 0.5 < EPD / L1R1 < 8

[0230] Equation 46 represents the relationship between the size of the entrance pupil diameter 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. Preferably, Equation 46 can be satisfied as: 1 < EPD / L1R1 < 2.

[0231] [Equation 47] -5 < |F1 / F2| < 0

[0232] In Equation 47, the focal lengths F1 and F2 of the first lens 101 and the second lens 102 can be set. Therefore, the resolution can be improved by adjusting the refractive power of the incident light of the first lens 101 and the second lens 102, and the TTL can be controlled. Preferably, Equation 47 can be satisfied as: -1 < F1 / F2 < 0, and the conditions: F1 > 0 and F2 < 0 can be satisfied.

[0233] [Equation 48] 1 < F12 / F < 5

[0234] By setting the combined focal length F12 and the total focal length F of the first lens and the second lens in Equation 48, the optical system 1000 can improve the resolution by adjusting the refractive power of the incident light, and the optical system 1000 can control the TTL. Preferably, Equation 48 can be satisfied as: 1 < F12 / F < 3.

[0235] [Equation 49] 1 < |F48 / F13| < 4

[0236] In Equation 49, the combined focal length F13 of the first lens to the third lens, that is, the focal length (mm) of the first lens group, and the combined focal length F48 of the fourth lens to the eighth lens, that is, the focal length of the second lens group, can be set. And when this condition is satisfied, the refractive powers of the first lens group and the second lens group can be controlled to improve the resolution, and the optical system can be set to a thin and compact size. Additionally, when Equation 49 is satisfied, the optical system 1000 can improve aberration characteristics, such as chromatic aberration and distortion aberration. Preferably, Equation 49 can satisfy: 1 < |F38 / F12| < 2. Here, the conditions F12 > 0, F38 > 0, and F38 > F12 can be satisfied.

[0237] [Equation 50] 0 < F1 / F < 3

[0238] In Equation 50, the total focal length F and the refractive power of the first lens 101 can be set, and the resolution can be improved. Equation 50 can satisfy: 0 < F1 / F < 2.

[0239] [Equation 50-1] 0 < |F2 / F| < 5 (where F > 0, F2 < 0)

[0240] [Equation 50-2] 1 < |F3 / F2| < 5 (where F3 > 0)

[0241] [Equation 50-3] 0 < |F4 / F| < 0.5 (where F4 < 0)

[0242] [Equation 50-4] 0 < F5 / F < 1 (where F5 > 0)

[0243] [Equation 50-5] 0 < F6 / F < 1 (where F6 > 0)

[0244] [Equation 50-6] 0 < |F7 / F| < 0.5 (where F7 < 0)

[0245] [Equation 50-7] 0 < |F8 / F| < 5 (where F8 < 0)

[0246] In Equations 50-1 to 50-7, F3, F4, F5, F6, F7, and F8 represent the focal lengths (mm) of the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 106, the seventh lens 107, and the eighth lens 108. And when this condition is satisfied, the resolution can be improved by controlling the refractive powers of the respective lenses, and the optical system can be set to a thin and compact size.

[0247] [Equation 51] 0 < F1 / F12 < 2

[0248] In Equation 51, the resolution of the first lens group can be adjusted by setting the focal length F1 of the first lens and the combined focal length F12 of the first lens and the second lens. Preferably, Equation 51 can satisfy: 0 < F1 / F12 < 1.5.

[0249] [Equation 52] 0 < F1 / |F38| < 2

[0250] By setting the focal length F1 of the first lens and the combined focal length F38 of the third lens to the eighth lens in Equation 52, the size and resolution of the optical system can be adjusted. Preferably, Equation 52 can satisfy: 0 < F1 / |F38| < 1. Here, when the aperture stop is provided on the sensor-side circumferential surface of the second lens, the combined focal length of the first lens to the third lens based on the position of the aperture stop is F13, and the combined focal length of the fourth lens to the eighth lens is F48. It can satisfy F12 > F13, and it can satisfy F38 > F48. In addition, the following conditions can be satisfied: F48 < 0 and |F48| > (F38 * 3).

[0251] [Equation 53] 0 < |F1 / F4| < 1

[0252] By setting the focal length F1 of the first lens and the focal length F4 of the fourth lens in Equation 53, the refractive power of the light incident on the first lens group and the second lens group can be controlled, and the size and resolution of the optical system can be adjusted. Preferably, Equation 53 can satisfy: 0 < |F1 / F4| < 0.5.

[0253] [Equation 54] 2mm < TTL < 20mm

[0254] In Equation 54, TTL represents the distance (mm) from the vertex of the first surface S1 of the first lens 101 to the imaging surface of the image sensor 300 on the optical axis OA. Preferably, Equation 54 can satisfy: 10 < TTL < 20, so a thin and compact optical system can be provided.

[0255] [Equation 55] 2mm < ImgH

[0256] Equation 55 sets the diagonal size (2 * ImgH) of the image sensor 300 to be more than 4mm, thereby providing an optical system with high resolution. Preferably, Equation 55 can satisfy: 4 ≤ ImgH ≤ 15 or 8 ≤ ImgH ≤ 15. Equation 55 can include at least one of the following Equation 55-1 to Equation 55-4.

[0257] [Equation 55-1] 1.5 < ImgH / ∑CT / < 2.2

[0258] [Equation 55-2] 1.6 < ImgH / ∑CG / < 2.3

[0259] [Formula 55-3] 0.8 <ImgH / ∑Index / <1.5

[0260] [Formula 55-4]0 <ImgH / ∑Abbe / <0.1

[0261] Formulas 55-1 to 55-4 can establish the relationship between ImgH and the sum of the center thicknesses of all lenses, the sum of the center distances between lenses, the sum of the refractive powers of all lenses, and the sum of the Abbe numbers of all lenses. Therefore, the resolution and size of an optical system having an ImgH of 4 mm or more or 8 mm can be adjusted.

[0262] [Formula 56] BFL < 2.5 mm

[0263] Formula 56 sets the BFL (back focal length) to be less than 2.5 mm, so that the installation space of the filter 500 can be ensured, and the assemblability of the components and the bonding reliability can be improved by the distance between the image sensor 300 and the last lens. Preferably, Formula 56 can satisfy: 0.8 <BFL<2.5。

[0264] [Formula 57]2 <F<20

[0265] In equation 57, the total focal length F can be set to be suitable for the optical system, preferably, it can satisfy: 5 <F<15。

[0266] [Formula 58]

[0267] FOV<120 degrees

[0268] In Formula 58, FOV (Field of View) represents the viewing angle (degrees) of the optical system 1000, and an optical system of less than 120 degrees may be provided. The FOV may be 70 degrees or more, for example, in the range of 70 degrees to 100 degrees.

[0269] [Equation 59] 0.5 <TTL / CA_Max<2

[0270] By setting the maximum effective diameter CA_Max and TTL between the object side surface and the sensor side surface of the plurality of lenses in equation 59, a thin and compact optical system can be provided. Preferably, equation 59 may satisfy: 0.5 <TTL / CA_Max<1。

[0271] [Equation 60] 0.5 <TTL / ImgH<3

[0272] Equation 60 can set the total optical axis length TTL of the optical system and the diagonal length (ImgH) of the optical axis from the image sensor 300. When the optical system 1000 according to the first embodiment satisfies Equation 60, the optical system 1000 can ensure a relatively large image sensor 300. For example, it can ensure the BFL for applications using a large image sensor 300 of about 1-inch size, and can have a smaller TTL, thus achieving high-definition image quality and a thin structure. Preferably, Equation 60 can satisfy: 0.8 < TTL / ImgH < 2. In addition, the conditions ImgH < TTL and 150 < TTL*ImgH can be satisfied.

[0273] [Equation 61] 0.01 < BFL / ImgH < 0.5

[0274] Equation 61 can set the optical axis distance between the image sensor 300 and the last lens and the diagonal length of the optical axis from the image sensor 300. When the optical system 1000 according to the first embodiment satisfies Equation 61, the optical system 1000 can ensure a relatively large image sensor 300. For example, it can ensure the BFL for applications using a large image sensor 300 of about 1-inch size, and can minimize the distance between the last lens and the image sensor 300, so that good optical performance can be obtained at the center and periphery of the FOV. Preferably, Equation 61 can satisfy: 0.1 ≤ BFL / ImgH ≤ 0.3.

[0275] [Equation 62] 4 < TTL / BFL < 10

[0276] Equation 62 can set the total optical axis length TTL of the optical system and the optical axis distance BFL (unit: mm) between the image sensor 300 and the last lens. When the optical system 1000 according to the first embodiment satisfies Equation 62, the optical system 1000 ensures the BFL and can be provided in a thin and compact manner. Equation 62 can satisfy: 6 < TTL / BFL < 10.

[0277] [Equation 63] 0.5 < F / TTL < 1.5

[0278] Equation 63 can set the total focal length F and the total optical axis length TTL of the optical system 1000. Therefore, a thin and compact optical system can be provided. Preferably, Equation 63 can satisfy: 0.5 < F / TTL < 1.2.

[0279] [Equation 63-1] 0 < F# / TTL < 0.5

[0280] Equation 63-1 can set the F-number F# and the total optical axis length TTL of the optical system 1000. Therefore, a thin and compact optical system can be provided.

[0281] [Equation 64] 3 < F / BFL < 10

[0282] Equation 64 can set the total focal length F of the optical system 1000 and the back focal length BFL (unit: mm) between the image sensor 300 and the last lens. When the optical system 1000 according to the first embodiment satisfies Equation 64, the optical system 1000 can have a set FOV and an appropriate focal length, and can provide a thin and compact optical system. In addition, the optical system 1000 can minimize the distance between the last lens and the image sensor 300, and thus has good optical characteristics at the peripheral portion of the FOV. Preferably, Equation 64 can satisfy: 5 < F / BFL < 10.

[0283] [Equation 65] 0.1 < F / ImgH < 3

[0284] Equation 65 can set the total focal length F (mm) of the optical system 1000 and the diagonal length ImgH from the optical axis of the image sensor 300. The optical system 1000 uses a relatively large image sensor 300 (e.g., about 1 inch) and can have improved aberration characteristics. Preferably, Equation 65 can satisfy: 0.8 ≤ F / ImgH < 2.

[0285] [Equation 66] 1 < F / EPD < 5

[0286] Equation 66 can set the total focal length F (mm) of the optical system 1000 and the entrance pupil diameter. Therefore, the overall brightness of the optical system can be controlled. Preferably, Equation 66 can satisfy: 1.5 ≤ F / EPD < 4.

[0287] [Equation 67] 0 < BFL / TD < 0.3

[0288] In Equation 67, the back focal length BFL between the image sensor 300 and the last lens and the optical axis distance TD of the lens are set. When this condition is satisfied, the optical system 1000 can provide a thin and compact optical system. Preferably, Equation 67 can satisfy: 0 < BFL / TD ≤ 0.2. When BFL / TD exceeds 0.3, BFL is designed to be larger than TD, so the size of the entire optical system becomes larger, making the manufacturing of the optical system difficult, and the distance between the eighth lens and the image sensor becomes longer, so the unnecessary light amount passing through the eighth lens and the image sensor may increase, resulting in a reduction in resolution, for example, deterioration of aberration characteristics.

[0289] [Equation 68] 0 < EPD / ImgH / FOV < 0.2

[0290] In equation 68, a relationship between the entrance pupil diameter EPD, the length of half the maximum diagonal length of the image sensor (ImgH), and the field of view (FOV) can be established. Therefore, the overall size and brightness of the optical system can be controlled. Preferably, equation 68 can satisfy: <EPD / ImgH / FOV<0.1。

[0291] [Formula 69] 10 <FOV / F#<55

[0292] Formula 69 can establish the relationship between the field of view and the F number of the optical system. Preferably, Formula 69 can satisfy: 30 <FOV / F#<50。

[0293] [Formula 70]0 <n1 / n2<1.5

[0294] When the refractive indices n1 and n2 at the d-line of the first lens 101 and the second lens 102 of Formula 70 satisfy the above range, the optical system can improve the resolution of the incident light. Preferably, 0 <n1 / n2<1。

[0295] [Formula 71] <n3 / n4<1.5

[0296] If the refractive indices n3 and n4 at the d-line of the third lens 103 and the fourth lens 104 of Formula 71 satisfy the above range, the optical system can improve the resolution of the incident light of the second lens group LG2. Preferably, Formula 71 can satisfy: <n3 / n4<1。

[0297] [Formula 72] <Inf71 / Inf72<1

[0298] In equation 72, the distance Inf71 from the optical axis OA to the critical point of the object side surface S13 of the seventh lens 107 and the distance Inf72 from the optical axis OA to the critical point of the sensor side surface S14 can be set. When the above conditions are met, the satisfactory aberration of the seventh lens can be controlled. Equation 72 can satisfy: 0.5 <Inf71 / Inf72<1。

[0299] [Formula 73] <Inf81 / Inf82<1

[0300] In Formula 73, the distance Inf81 from the optical axis OA to the critical point of the object side surface S15 of the eighth lens 108 and the distance Inf82 from the optical axis OA to the critical point of the sensor side surface S16 of the eighth lens 108 can be set. When the above conditions are met, the satisfactory aberration of the eighth lens can be controlled. Formula 73 can satisfy: 0.1 <Inf61 / Inf72<0.5。

[0301] [Formula 74]1 <Inf72 / Inf81<5

[0302] In equation 74, the distance Inf72 from the optical axis OA to the critical point of the sensor side surface S14 of the seventh lens 107 and the distance Inf81 from the optical axis OA to the critical point of the object side surface S15 of the eighth lens 108 can be set. When this condition is met, satisfactory aberrations of the seventh lens and the eighth lens can be controlled. Equation 74 can satisfy: <Inf72 / Inf81<4。

[0303] [Equation 75] 0.3 <Inf71 / r71<0.7

[0304] In equation 75, the distance Inf71 from the optical axis OA to the critical point of the object side surface S13 of the seventh lens 107 and the effective radius r71 of the object side surface of the seventh lens 107 can be set. When the above conditions are met, the satisfactory aberration of the object side surface of the seventh lens can be controlled. Equation 75 can satisfy: 0.2 <Inf71 / r71<0.6。

[0305] [Equation 76] 0.3 <Inf72 / r72<0.75

[0306] In equation 76, the distance Inf72 from the optical axis OA to the critical point of the sensor side surface S14 of the seventh lens 107 and the effective radius r72 of the sensor side surface of the seventh lens 107 can be set. When the above conditions are met, the satisfactory aberration of the sensor side surface of the seventh lens can be controlled. Equation 76 can satisfy: 0.4 <Inf72 / r72<0.65。

[0307] [Formula 77]0 <Inf82 / r82<0.5

[0308] In equation 77, the distance Inf82 from the optical axis OA to the critical point of the sensor side surface S16 of the eighth lens 108 and the effective radius r82 of the sensor side surface S16 of the eighth lens 108 can be set. When the above conditions are met, the satisfactory aberration of the object side surface of the eighth lens can be controlled. Equation 77 can satisfy: 0.2 <Inf82 / r82<0.5。

[0309] [Equation 78] 1<(Inf72 / r72) / (Inf82 / r82)<2

[0310] In Formula 78, the ratio of the distance Inf72 to the critical point of the sensor side surface S14 of the seventh lens 107 to the effective radius r72 of the sensor side surface S14, and the ratio of the distance Inf82 to the critical point of the sensor side surface S16 of the eighth lens 108 to the effective radius r82 of the sensor side surface S16 can be set, and when the above conditions are met, the satisfactory aberration of the sensor side surfaces of the seventh lens and the eighth lens can be controlled. Formula 78 can satisfy: 1<(Inf72 / r72) / (Inf82 / r82)<1.55.

[0311] [Equation 79] 5<(TTL / ImgH)*n<15

[0312] Preferably, Formula 79 may satisfy: 8<(TTL / ImgH)*n<12.

[0313] [Formula 80] 4<(F / ImgH)*n<14

[0314] Preferably, Formula 80 may satisfy: 6<(F / ImgH)*n<11.

[0315] [Formula 81]25<(TD_LG2 / TD_LG1)*n<55

[0316] [Formula 82]20<(CT_Max+CG_Max)*n<30

[0317] [Equation 83] 100 < (FOV * TTL) / n < 200

[0318] [Equation 84] (TTL*n)>FOV

[0319] [Equation 85](v2*n2)<(v1*n1)

[0320] In Formula 79 to Formula 85, n is the total number of lenses, and according to the total number of lenses, the optical axis distance TD_LG1 of the first lens group LG1, the optical axis distance TD_LG2 of the second lens group LG2, the maximum center thickness CT_Max, the maximum center distance CG_Max, FOV, TTL, etc. can be set. Therefore, the chromatic aberration, resolution, size, etc. of the optical system having 9 or less lenses can be controlled.

[0321] [Formula 86]

[0322]

[0323] In Formula 86, 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 refer to the distance from any position on the aspherical surface to the optical axis in a direction perpendicular to the optical axis. c may refer to the curvature of the lens, and K may refer to a conic constant. In addition, A, B, C, D, E, and F may represent aspherical constants.

[0324] The optical system 1000 according to the first embodiment may satisfy at least one or two of Formulas 1 to 85. In this case, the optical system 1000 has improved optical characteristics and improved resolution, and may improve aberration and distortion characteristics. In addition, the optical system 1000 may ensure the BFL applied to the large image sensor 300, and minimize the distance between the last lens and the image sensor 300, thereby having good optical performance in the central and peripheral portions of the FOV. In addition, when the optical system 1000 satisfies at least one of Formulas 1 to 85, the optical system 1000 includes an image sensor 300 having a relatively large size, and may have a relatively small TTL value, and may provide a thinner compact optical system and a camera module having the optical system. In the optical system 1000 according to the first embodiment, the distance between the plurality of lenses 100 may have a value set according to the region.

[0325] Figure 3 It is shown that according to Figure 1 An example of lens data of the first embodiment of the optical system.

[0326] like Figure 3As shown, the optical system according to the first embodiment represents the radius of curvature on the optical axis OA of the first lens 101 to the eighth lens 108, the center thickness CT of the lens, the center distance CG between the lenses, the refractive index (588nm) at the d line, the Abbe number and the effective radius (semi-aperture) and the focal length. The sum of the refractive indices of the plurality of lenses 100 is greater than 10, and the sum of the Abbe numbers is greater than 300, and the sum of the center thicknesses of all the lenses is greater than 5mm, for example, in the range of 5mm to 8mm. The sum of the center distances between the first lens to the eighth lens on the optical axis may be greater than 5mm, for example, in the range of 5mm to 8mm, and may be less than the sum of the center thicknesses of the lenses. In addition, the average value of the effective diameter of each lens surface in the plurality of lenses 100 is greater than 8mm, for example, in the range of 8mm to 10mm. The average value of the center thickness of each lens may be less than 1mm, for example, in the range of 0.5mm to 1mm. The sum of the effective diameters of the respective lens surfaces in the plurality of lenses 100 is the sum of the effective diameters of the first surface S1 to the sixteenth surface S16, and may be 120 mm or more, for example, in the range of 120 mm to 180 mm. In the absolute value of the focal length, the focal length of the fourth lens 104 is the largest, and any one of the focal lengths of the first lens 101 and the eighth lens 108 is the smallest. For example, the focal length of the eighth lens 108 may be the smallest.

[0327] like Figure 4 As shown, in the first and second embodiments, the lens surface of at least one or all of the multiple lenses may include an aspheric surface having a 30th order aspheric coefficient. For example, the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 106, the seventh lens 107, and the eighth lens 108 may include lens surfaces having a 30th order aspheric coefficient from the first surface S1 to the sixteenth surface S16. As described above, the aspheric surface having a 30th order aspheric coefficient (a value other than "0") can particularly significantly change the aspheric shape of the peripheral portion, so the optical performance of the peripheral portion of the FOV can be well corrected.

[0328] like Figure 5As shown, the first thickness T1 to the eighth thickness T8 of the first lens 101 to the eighth lens 108 can be expressed as a distance of more than 0.1 mm in the direction Y from the center to the edge of each lens, and the distance between adjacent lenses can be expressed as a distance of more than 0.1 mm in the direction from the center to the edge based on the first distance G1 between the first lens and the second lens, the second distance G2 between the second lens and the third lens, the third distance G3 between the third lens and the fourth lens, the fourth distance G4 between the fourth lens and the fifth lens, the fifth distance G5 between the fifth lens and the sixth lens, the sixth distance G6 between the sixth lens and the seventh lens, and the seventh distance G7 between the seventh lens and the eighth lens. In the first thickness T1, the maximum thickness can be more than twice the minimum thickness, for example, in the range of 2 times to 4 times. The maximum distance of the first distance G1 can be more than 1 times the difference between the minimum distances, for example, in the range of 1 times to 1.5 times. The maximum thickness of the second thickness T2 can be more than 1.1 times the minimum thickness, for example, 1.1 times to 2.1 times. The maximum distance of the second distance G2 may be more than 5 times the minimum distance, for example, 5 to 10 times. In the third thickness T3, the maximum thickness may be more than 1.1 times the minimum thickness, for example, 1.1 to 2.1 times. The maximum distance of the third distance G3 may be more than 5 times the difference between the minimum distances, for example, 5 to 10 times. The maximum thickness of the fourth thickness T4 may be 1.1 times the minimum thickness, for example, in the range of 1.1 to 2.2 times. The maximum distance of the fourth distance G4 may be more than 1.2 times the minimum distance, for example, 1.2 to 2.5 times. In the fifth thickness T5, the maximum thickness may be more than 1.1 times the minimum thickness, for example, 1 to 3 times. The maximum distance of the fifth distance G5 may be more than 1.1 times the minimum distance, for example, in the range of 1.1 to 2.5 times. The maximum thickness of the sixth thickness T6 may be more than 1.1 times the minimum thickness, for example, 1.1 to 3.1 times. The maximum distance of the sixth distance G6 may be at least 2 times the minimum distance, for example, in the range of 2 times to 10 times. In the seventh thickness T7, the maximum thickness may be more than 1.5 times the minimum thickness, for example, 1.5 times to 4 times. The maximum distance of the seventh distance G7 may be more than 2 times the minimum distance, for example, in the range of 2 times to 10 times. The maximum thickness of the eighth thickness T8 may be more than 2 times the minimum thickness, for example, 2 times to 5 times. By using the above-mentioned first thickness T1 to eighth thickness T8 and first distance G1 to seventh distance G7, the optical system can be set to a thin and compact size.

[0329] Figure 6 Shown from Figure 1The height (sag value) of the lens surface whose distance is 0.1 mm or more is from a straight line in the Y circumferential direction orthogonal to the centers of the object-side surface L7S1 and the sensor-side surface L7S2 of the seventh lens 107 and the object-side surface L8S1 and the sensor-side surface L8S2 of the eighth lens 108 in the optical system, and Fig. 9 Show Figure 5 The curve diagram of Figure 6 and Fig. 9 As shown in FIG. 1 , it can be seen that the critical point of the object side surface L7S1 and the sensor side surface L7S2 of the seventh lens 107 appears below 4.5 mm from the optical axis, and the critical point P1 of the object side surface (see Figure 2 ) appears to be closer to the optical axis than the critical point P2 of the sensor side surface, and the concave value of L7S2 in the sensor side direction appears to be greater than the concave value of L7S1.

[0330] In addition, the concave value of the sensor-side surface L8S2 of the eighth lens 108 in the sensor-side direction may be greater than the concave value of the object-side surface L8S1, and as Figure 2 and Fig. 9 As shown, the critical point P2 on the object-side surface of the eighth lens 108 is closer to the optical axis than the other critical points P1, P2, and P4.

[0331] Figure 7 is a graph showing the diffraction MTF characteristics of the optical system according to the embodiment of the present invention, and Figure 8 Graph showing aberration characteristics of an optical system according to an embodiment of the present invention. Figure 7 and Figure 8 As shown, the aberration curve graphs of the optical system according to the embodiment are curve graphs for measuring spherical aberration, astigmatism field curve and distortion from left to right. The X-axis can represent focal length (mm) and distortion (%), and the Y-axis can represent the height of the image. In addition, the curve graph for spherical aberration is a curve graph for light in wavelength bands of about 470nm, about 510nm, about 555nm, about 610nm and about 660nm, and the curve graph for astigmatism and distortion aberration is a curve graph for light in a wavelength band of about 555nm. Figure 8 In the aberration diagram, it can be interpreted that the closer the curves are to the Y axis, the better the aberration correction function. Figure 8, it can be seen that the measured values ​​of the optical system 1000 according to the embodiment are adjacent to the Y axis in most areas. That is, the optical system 1000 according to the embodiment can have improved resolution and can have good optical performance not only in the center of the FOV but also in the peripheral part. As confirmed in the first embodiment, the lens system according to the first embodiment of the present invention is compact and lightweight, has a lens configuration of 9 or less elements (e.g., 8 elements), and has good spherical aberration, astigmatism, distortion aberration, chromatic aberration, and coma at the same time. Since it is calibrated and can be implemented with high resolution, it can be used as a built-in camera optical device.

[0332] Table 1 shows the items of the above-mentioned various formulas in the optical system 1000 according to the embodiment, specifically, TTL, BFL, F value, ImgH, F1, F2, F3, F4, F5, F6, F7 and F8, edge thickness, edge distance, synthetic focal length, etc. of the optical system 1000.

[0333] [Table 1]

[0334]

[0335]

[0336] Table 2 shows Figure 1 The result values ​​of the above equations 1 to 40 in the optical system 1000. Referring to Table 2, it can be seen that the optical system 1000 satisfies at least one, two or three of equations 1 to 40. Therefore, the optical system 1000 can improve the optical performance and optical characteristics of the central part and the peripheral part of the FOV.

[0337] [Table 2]

[0338]

[0339]

[0340] Table 3 shows Figure 1 The result values ​​of the above equations 43 to 85 in the optical system 1000. Referring to Table 3, the optical system 1000 may satisfy at least one or two of equations 1 to 42 and at least one, two or three of equations 43 to 85. Therefore, the optical system 1000 may improve the optical performance and optical characteristics of the central portion and the peripheral portion of the FOV.

[0341] [Table 3]

[0342]

[0343]

[0344] Will refer to Figures 10 to 19 For the same configuration as the first embodiment, reference is made to the description of the first embodiment, and redundant description will be omitted. Fig.10 and Fig.11 , lens 100A includes a first lens group LG1 and a second lens group LG2, and each of the first lens group LG1 and the second lens group LG2 includes at least two lenses. The number of lenses of the second lens group LG2 may be 2.5 to 4 times the number of lenses of the first lens group LG1. The first lens group LG1 may include three or less lenses, for example, two lenses. The second lens group LG2 may include more than 5 and less than 8 lenses. The number of lenses of the second lens group LG2 may be more than 5 times the number of lenses of the first lens group LG1. For example, the second lens group LG2 may include 7 lenses.

[0345] In the optical system 1000, the TTL may be less than 70% of the diagonal length of the image sensor 300, for example, in the range of 40% to 69% or 50% to 65%. Therefore, a thin optical system and a camera module having the same may be provided. The total number of lenses in the first lens group LG1 and the second lens group LG2 is 8 to 10.

[0346] The first lens group LG1 and the second lens group LG2 may have positive (+) refractive power. The first lens group LG1 may include a group of lenses having a meniscus shape convex toward the object. In the second lens group LG2, the number of lenses having a critical point on at least one of the object side surface and the sensor side surface may be equal to or greater than the number of lenses without a critical point. Therefore, by having a lens surface with a critical point of the second lens group LG2, the TTL may be reduced and the size of the image sensor 300 may be increased. The sensor side surface of the first lens group LG1 may be concave, and the object side surface of the second lens group LG2 may be concave. In addition, two lenses facing each other in the first lens group LG1 and the second lens group LG2 may have opposite refractive powers.

[0347] Two lenses adjacent to a region between the first lens group LG1 and the second lens group LG2 may satisfy the following conditions.

[0348] Condition 1: Refractive index of lens with positive refractive power < refractive index of lens with negative refractive power Condition 1: Dispersion value of lens with positive refractive power > dispersion value of lens with negative refractive power Therefore, chromatic aberration occurring between lenses can be corrected mutually.

[0349] The difference between the focal length of the second lens group LG2 and the focal length of the first lens group LG1 may be 10 or less, for example, 5 or less. Therefore, the optical system 1000 according to the second embodiment may have improved aberration control characteristics, for example, chromatic aberration and distortion aberration, by controlling the refractive power and focal length of each of the lens groups LG1 and LG2, and may have good optical performance at the center and periphery of the FOV.

[0350] 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 lens (e.g., 112) closest to the sensor in the first lens group LG1, and may be less than the center thickness of the lens (e.g., 113) closest to the object in the second lens group LG2. The optical axis distance between the first lens group LG1 and the second lens group LG2 may be more than 43% of the optical axis distance of the first lens group LG1, for example, in the range of 43% to 63% or 48% to 58% of the optical axis distance of the first lens group LG1. The optical axis distance between the first lens group LG1 and the second lens group LG2 may be less than 19% of the optical axis distance of the second lens group LG2, for example, in the range of 5% to 19% or 5% to 14%.

[0351] The lens with the smallest effective diameter in the first lens group LG1 may be the lens closest to the second lens group LG2. The lens with the smallest effective diameter in the second lens group LG2 may be the lens closest to the first lens group LG1. Therefore, even in the central part and the peripheral part of the FOV, the optical system 1000 may have good optical performance, and chromatic aberration and distortion aberration may be improved. The effective diameter gradually decreases from the object side lens surface of the first lens group LG1 to the lens surface adjacent to the second lens group LG2, and may gradually increase from the object side lens surface of the second lens group LG2 to the lens adjacent to the image sensor. The lens surface may include the object side surface and the sensor side surface of each lens. That is, the effective diameter of the lens gradually decreases from the adjacent lens closest to the object to the adjacent lens surface between the first lens group LG1 and the second lens group LG2, and may gradually increase from the adjacent lens surface between the first lens group LG1 and the second lens group LG2 to the lens surface of the last lens. Therefore, since the lens groups LG1 and LG2 have different refractive powers and the difference in the effective diameter of the lens surface, light can be guided to the peripheral part of the image sensor 300 of about 1 inch (25.4 mm). The effective diameter difference between the lenses with the smallest effective diameter in the first lens group LG1 and the second lens group LG2 may be 0.25 mm or less. Therefore, the incident light may be refracted to the effective area between the first lens group LG1 and the second lens group LG2, and then refracted to the peripheral portion of the image sensor 300.

[0352] Among the lenses of the first lens group LG1, the lens closest to the object may have a positive (+) refractive power, and among the second lens group LG2, the lens closest to the sensor may have a negative (-) refractive power. In the optical system 1000, the number of lenses with positive (+) refractive power may be greater than the number of lenses with negative (-) refractive power. Among the second lens group LG2, the number of lenses with positive (+) refractive power may be greater than the number of lenses with negative (-) refractive power. Accordingly, chromatic aberration between the lenses of the second lens group LG2 can be corrected. Additionally, the ratio of the number of lenses with positive refractive power to the number of lenses with negative refractive power within the optical system 1000 may be selected from 1.5:1 to 2:1, and chromatic aberration between the lenses can be corrected. Within the optical system 1000, the sum of the focal lengths of the lenses with positive refractive power may be greater than the absolute value of the sum of the focal lengths of the lenses with negative refractive power. Accordingly, chromatic aberration and resolution can be improved by adjusting the refractive power of each lens and the positive and negative focal lengths.

[0353] The filter 500 may be disposed between the image sensor 300 and the lens closest to the sensor among the plurality of lenses. For example, when the optical system 1000 has nine lenses, the filter 500 may be disposed between the image sensor 300 and the ninth lens 119 which is the last lens. The aperture stop may be disposed around any one of the lenses of the first lens group LG1. For example, the aperture stop may be disposed around the object-side surface or the sensor-side surface of the second or third lens on the object. Alternatively, at least one lens selected from the plurality of lenses may be used as the aperture stop. The aperture stop may satisfy the following condition: SD < EFL or SD < ImgH. Additionally, the condition: SD < TTL may be satisfied. Additionally, the following condition may be satisfied: F < TTL. The difference between F and ImgH may be 2 mm or less, for example, 0.01 mm to 2 mm or 0.01 mm to 1 mm. The FOV of the optical system 1000 may be less than 120 degrees, for example, greater than 70 degrees and less than 100 degrees. The F-number F# of the optical system 1000 may be greater than 1 but less than 10, for example, 1.1 ≤ F# ≤ 5. When it is 3 or less, a bright image can be provided. Additionally, F# may be less than EPD. Accordingly, the optical system 1000 has a thin size, can control incident light, and can have improved optical characteristics within the FOV. The optical system 1000 according to the second embodiment may further include a reflection member (not shown) for changing the optical path. The reflection member may be implemented as a prism that reflects incident light from the first lens group LG1 in the direction of the lens.

[0354] The lens 100A may include a first lens 111 to a ninth lens 119. The first lens group LG1 may include a first lens 111 and a second lens 112, and the second lens group LG2 may include a third lens 113 to a ninth lens 119. The optical axis distance between the second lens 112 and the third lens 113 may be the optical axis distance between the first lens group LG1 and the second lens group LG2, and may be set to be 0.50 mm or more to suppress an increase in the effective diameters of the third lens 113 and the fourth lens 114. Among the first lens 111 to the ninth lens 119, the number of lenses having a meniscus shape protruding from the optical axis toward the object may be 4 or more or 5 or more. Among all the lenses, the ratio of the meniscus lens protruding toward the object side to the meniscus lens protruding toward the sensor may be any one of 6:3, 5:4, or 4:5.

[0355] The first lens 111 may have a positive (+) refractive power. The first lens 111 may be made of a plastic material. The first surface S1 of the first lens 111 may have a convex shape, and the second surface S2 may have a concave shape. Since the first lens 111 has a meniscus shape that is convex toward the object, the amount of incident light may be increased. Alternatively, the first lens 111 may have a lens shape that is convex on both sides. Alternatively, the first surface S1 may have a concave shape. At least one of the first surface S1 and the second surface S2 may be an aspherical surface, and the aspherical coefficients of the first surface S1 and the second surface S2 may be aspherical surfaces. Fig.13 In the arrangement shown, L1 is the first lens 111, L1S1 is the first surface, and L1S2 is the second surface.

[0356] The second lens 112 may have a negative (-) refractive power. The second lens 112 may be made of a plastic material. The first lens 111 and the second lens 112 have positive and negative refractive powers, and may correct chromatic aberration. In addition, an aperture stop may be provided around the fourth surface S4 on the sensor side of the second lens 112. The third surface S3 of the second lens 112 may have a convex shape, and the fourth surface S4 may have a concave shape. That is, the second lens 112 may have a meniscus shape that is convex toward the object on the optical axis OA. Alternatively, the third surface S3 may have a convex shape, and the fourth surface S4 may have a convex shape. At least one of the third surface S3 and the fourth surface S4 may be an aspherical surface, and the aspherical coefficients of the third surface S3 and the fourth surface S4 may be as Fig.13 In the arrangement shown, L2 is the second lens 112, L2S1 is the third surface, and L2S2 is the fourth surface.

[0357] The third lens 113 may have a positive (+) refractive power. The third lens 113 may be made of a plastic material. The second lens 112 and the third lens 113 have positive and negative refractive powers, so chromatic aberration occurring in lenses made of the same material can be corrected. Since the third lens 113 is located on the sensor side where the aperture stop of the second lens 112 is located and has a positive refractive power, and light is refracted in the optical axis direction by the aperture stop, the sensor side lens relative to the aperture stop can prevent the effective diameter from increasing. The fifth surface S5 of the third lens 113 may have a concave shape, and the sixth surface S6 may have a convex shape. The third lens 113 may have a meniscus convex toward the sensor on the optical axis OA. Differently, on the optical axis OA, the fifth surface S5 may have a concave shape, and the sixth surface S6 may have a concave shape. Alternatively, the third lens 113 may have a meniscus convex toward the object. The third surface S3 and the fourth surface S4 of the third lens 113 may be set to have no critical point from the optical axis OA to the end of the effective area. At least one of the fifth surface S5 and the sixth surface S6 may be an aspherical surface, and the aspherical coefficients of the fifth surface S5 and the sixth surface S6 are as follows: Fig.13 In the arrangement shown, L3 is the third lens 113, L3S1 is the fifth surface, and L3S2 is the sixth surface.

[0358] The fourth lens 114 may have a negative (-) refractive power. The fourth lens 114 may be made of a plastic material. Since the third lens 113 and the fourth lens 114 are arranged to have positive and negative refractive powers, chromatic aberration occurring in lenses made of the same material may be corrected. The seventh surface S7 of the fourth lens 114 may have a convex shape, and the eighth surface S8 may have a concave shape. At least one or both of the seventh surface S7 and the eighth surface S8 of the fourth lens 114 may be set to have no critical point. At least one or both of the seventh surface S7 and the eighth surface S8 may be aspherical, and the aspherical coefficients may be as Fig.13 As shown in the arrangement, L4 is the fourth lens 114, L4S1 is the seventh surface, and L4S2 is the eighth surface. The fifth lens 115 may have a positive refractive power. The fifth lens 115 may be made of a plastic material. The ninth surface S9 of the fifth lens 115 may have a convex shape, and the tenth surface S10 may have a concave shape. At least one or both of the ninth surface S9 and the tenth surface S10 may be aspherical, and the aspherical coefficients of the ninth surface S9 and the tenth surface S10 are as follows: Fig.13 In the arrangement shown, L5 is the fifth lens 115, L5S1 is the ninth surface, and L5S2 is the tenth surface.

[0359] The sixth lens 116 may have a positive refractive power. The sixth lens 116 may be made of a plastic material. On the optical axis OA, the eleventh surface S11 of the sixth lens 116 may have a concave shape, and the twelfth surface S12 may have a convex shape. At least one or both of the eleventh surface S11 and the twelfth surface S12 of the sixth lens 116 may be set such that there is no critical point from the optical axis OA to the end of the effective area. At least one or both of the eleventh surface S11 and the twelfth surface S12 may be aspherical, and the aspherical coefficient is set as Fig.13 shown, L6 is the sixth lens 116, L6S1 is the eleventh surface, and L6S2 is the twelfth surface. The seventh lens 117 is the (n - 2)th lens and may have a positive refractive power. The seventh lens 117 may be made of a plastic material. The focal length (absolute value) of the seventh lens 117 is the largest among the lenses 100A. Therefore, the focal length difference between the seventh lens 117 and the adjacent lens may be 30 mm or more. For example, when the absolute value of the focal length of the seventh lens 117 is F7, the focal length of the sixth lens 116 is F6, and the focal length of the eighth lens 118 is F8, the following condition may be satisfied: F8 < F6 < F7. Additionally, since the fifth lens 115, the sixth lens 116, the seventh lens 117, and the eighth lens 118 have positive refractive powers, and the ninth lens 119 has a negative refractive power, chromatic aberration occurring in lenses made of the same material can be corrected. The thirteenth surface S13 of the seventh lens 117 may have a concave shape, and the fourteenth surface S14 may have a convex shape. At least one or both of the thirteenth surface S13 and the fourteenth surface S14 may be aspherical, and the aspherical coefficient is set as Fig.13 shown, L7 is the seventh lens 117, L7S1 is the thirteenth surface, and L7S2 is the fourteenth surface.

[0360] The eighth lens 118 is the (n - 1)th lens and may have a positive refractive power. The eighth lens 118 may be made of a plastic material. The fifteenth surface S15 of the eighth lens 118 may have a convex shape, and the sixteenth surface S16 may have a concave shape. Alternatively, the eighth lens 118 may have a meniscus shape protruding from the optical axis toward the sensor or a shape concave on both sides. At least one or both of the fifteenth surface S15 and the sixteenth surface S16 of the eighth lens 118 may have a critical point. The fifteenth surface S15 and the sixteenth surface S16 may be aspherical, and the aspherical coefficient is set as Fig.13 shown, L8 is the eighth lens 118, L8S1 is the fifteenth surface, and L8S2 is the sixteenth surface.

[0361] As Fig.11As shown, the first critical point P1 of the fifteenth surface S15 of the eighth lens 118 can be located at a position greater than 48% of the effective radius from the optical axis OA, for example, in the range of 48% to 68% or in the range of 53% to 63%. The second critical point P2 of the sixteenth surface S16 can be located at a position greater than 50% of the effective radius r82 from the optical axis OA, for example, in the range of 50% to 70% or in the range of 55% to 65%. The second critical point P2 can be located at the same position as the first critical point P1, or closer to the edge, and the separation distance between the first critical point P1 and the second critical point P2 can be less than 1 mm. Therefore, the sixteenth surface S16 can further refract the light incident on the fifteenth surface S15 in the edge direction, thereby reducing TTL.

[0362] The ninth lens 119 is an n-th lens and may have negative refractive power on the optical axis OA. The ninth lens 119 may be made of a plastic material. The ninth lens 119 may be a lens closest to the sensor or a last lens in the optical system 1000. In the ninth lens 119, the object-side seventeenth surface S17 may have a convex shape, and the sensor-side eighteenth surface S18 may have a concave shape. At least one or both of the seventeenth surface S17 and the eighteenth surface S18 of the ninth lens 119 may have a critical point. The seventeenth surface S17 and the eighteenth surface S18 may be aspherical surfaces, and the aspherical coefficients may be as follows: Fig.13 In the arrangement shown, L9 is the ninth lens 119, L9S1 is the seventeenth surface, and L9S2 is the eighteenth surface.

[0363] like Fig.11 As shown, the third critical point P3 of the seventeenth surface S17 of the ninth lens 119 can be located at a position below 25% of the effective radius of the optical axis OA, for example, in the range of 5% to 25% or in the range of 10% to 20%. The fourth critical point P4 of the eighteenth surface S18 can be located in a range of more than 26% (for example, 26% to 46% or 31% to 41%) of the effective radius r92 based on the optical axis OA. The third critical point P3 can be closer to the optical axis OA than the first critical point P1, the second critical point P2, and the fourth critical point P4, and the separation distance between the third critical point P3 and the fourth critical point P4 can be greater than 1mm. Therefore, the seventeenth surface S17 refracts light toward the center of the image sensor 300, and the eighteenth surface S18 refracts light toward the peripheral portion of the image sensor 300. Therefore, the TTL of the optical system 1000 can be reduced.

[0364] Considering the optical characteristics of the optical system 1000, the positions of the critical points of the eighth lens 118 and the ninth lens 119 are preferably arranged at positions that satisfy the above ranges. Specifically, it is desirable for the positions of the critical points to satisfy the above ranges in order to control the optical characteristics of the optical system 1000, such as chromatic aberration, distortion characteristics, aberration characteristics, and resolution. Therefore, the path of light emitted through the lens to the image sensor 300 can be effectively controlled. Thus, the optical system 1000 according to the second embodiment can have improved optical characteristics even in the central and peripheral portions of the FOV.

[0365] As Fig.11 shown, the distances from the optical axis OA to the ends of the effective regions of each of the fifteenth surface S15 and the sixteenth surface S16 of the eighth lens 118 are effective radii defined as r81 and r82. The distances from the optical axis OA to the ends of the effective regions of each of the seventeenth surface S17 and the eighteenth surface S18 of the ninth lens 119 are effective radii defined as r91 and r92. The distances from the optical axis OA to the critical points P1, P2, P3, and P4 of the fifteenth surface S15, the sixteenth surface S16, the seventeenth surface S17, and the eighteenth surface S18 can be defined as follows.

[0366] Inf81: The straight-line distance from the center of the fifteenth surface S15 to the first critical point P1.

[0367] Inf82: The straight-line distance from the center of the sixteenth surface S16 to the second critical point P2.

[0368] Inf91: The straight-line distance from the center of the seventeenth surface S17 to the third critical point P3.

[0369] Inf92: The straight-line distance from the center of the eighteenth surface S18 to the fourth critical point P4.

[0370] The distances from the centers of the respective lens surfaces to the critical points can have the following relationships.

[0371] Condition 1: Inf81 < Inf82, Condition 2: Inf91 < Inf92, Condition 3: Inf91 < Inf92 < Inf82, Condition 4: (Inf82 - Inf81) < (Inf92 - Inf91)

[0372] The first critical point P1 and the second critical point P2 may be located at a distance of 2 mm or more from the optical axis OA, for example, in a range of 2 mm to 5 mm, and the third critical point P3 may be located at a distance of 2 mm or less from the optical axis OA, for example, in a range of 0.5 mm to 1.5 mm. The fourth critical point P4 may be located at a distance of 2.3 mm or more from the optical axis, for example, in a range of 2.3 mm to 4.3 mm. Therefore, the eighth lens 118 and the ninth lens 119 may refract incident light toward the central portion and the peripheral portion.

[0373] The inclination angle between the optical axis OA and the normal line K6 (which is a straight line perpendicular to the tangent line K5 passing through any point of the eighteenth surface S18 of the ninth lens 119) may be a first angle θ3, and when the first angle θ3 is maximum, it may be greater than 5 degrees and less than 65 degrees, for example, in the range of 44 to 64 degrees or 49 to 59 degrees. Therefore, by the inclination angle of the eighteenth surface S18, the TTL may be reduced and the size of the image sensor 300 may be increased. The inclination angle between the normal line K4 perpendicular to the tangent line K3 passing through the sixteenth surface S16 of the eighth lens 118 and the optical axis may be a second angle θ2, and when the second angle θ2 is maximum, it may be greater than 5 degrees and less than 65 degrees, for example, in the range of 17 to 37 degrees or 22 to 32 degrees. Therefore, the maximum inclination angle θ2 of the sixteenth surface S16 may be less than the maximum inclination angle of the eighteenth surface S18. Therefore, the light traveling through the eighth lens 118 may be guided to the entire area of ​​the ninth lens 119. The maximum inclination angle between the optical axis and the normal to the tangent line of the seventeenth surface S17 passing through the ninth lens 119 is θ4, and the maximum inclination angle between the optical axis and the normal to the tangent line of the fifteenth surface S15 passing through the eighth lens 118 is θ4, when the maximum inclination angle between the perpendicular normal and the optical axis is defined as θ5, and θ2 and θ3 are the maximum inclination angles, at least one of the following conditions may be satisfied.

[0374] Condition 1: θ2<θ3, Condition 2: θ4<θ4, Condition 3: θ4<θ3

[0375] Condition 4: 0<θ3-θ4<10, Condition 5: 0<θ3-θ2<10

[0376] Condition 6: 5<θ5-θ2<20

[0377] Therefore, by increasing the inclination angle between the object-side surface and the sensor-side surface of the eighth lens 118, the inclination angle of the outer portion of the ninth lens 119 may not increase. Therefore, the TTL may be reduced and the size of the image sensor 300 may be increased.

[0378] The radii of curvature of the seventeenth surface S17 and the eighteenth surface S18 of the ninth lens 119 on the optical axis can be defined as L9R1 and L9R2. The radii of curvature can satisfy at least one of the following conditions 1 to 9 to improve the aberration characteristics of the optical system.

[0379] Condition 1: (L2R1 + L2R2) < L1R2, Condition 2: (L2R1 - L2R2) < L1R2 - L1R1

[0380] Condition 3: (|L3R2| * 2) < |L3R1|, Condition 4: (L4R1 * L4R2) < |L3R1 + L3R2|

[0381] Condition 5: (L5R1 * L5R2) < |L3R1|, Condition 6: |L6R1 + L6R2| < |L3R1| (where L6R1, L6R2 < 0)

[0382] Condition 7: |L7R1 + L7R2| < |L3R1| (where L7R1, L7R2 < 0)

[0383] Condition 8: |L7R1 + L7R2| < L8R1 * L8R2 (where L8R1 < L8R2)

[0384] Condition 9: L9R1 + L9R2 < |L7R1|, Condition 10: L9R1 * L9R2 < L1R1 + L1R2

[0385] Condition 11: (L1R1 + L1R2 + L2R1 + L2R2) < |L3R1| (where L3R1 < 0)

[0386] On the optical axis OA, the average radius of curvature of any one of the second lens 112 and the ninth lens 119 can be the smallest in the optical system, and the fourth surface S4 of the second lens 112 and the ninth lens 119 can have the smallest average radius of curvature in the optical system. The difference in the radius of curvature of the eighteenth surface S18 can be 4 mm or less. The average value of the radii of curvature (absolute value) of the fifth surface S5 and the sixth surface S6 of the third lens 113 can be the largest within the optical system 1000. By setting the radii of curvature of the respective lenses, good optical performance can be provided at the focal lengths of the respective lenses.

[0387] The effective diameters of the first lens 111 to the ninth lens 119 can be defined as CA1 to CA9. The effective diameter CA9 of the ninth lens 119 can have the largest effective diameter and can be 10 mm or more. The effective diameter CA9 of the ninth lens 119 is the average value of the effective diameters of the object-side surface and the sensor-side surface. The effective diameter CA9 of the ninth lens 119 can be greater than twice the radius of curvature of the object-side surface S1 of the first lens 111.

[0388] The effective diameters of the seventeenth surface S17 and the eighteenth surface S18 of the ninth lens 119 on the optical axis can be defined as CA91 and CA92. These effective diameters are factors affecting the aberration characteristics of the optical system and can satisfy at least one of the following conditions.

[0389] Condition 1: CA22 < CA12 < CA11, Condition 2: CA22 < CA32 < CA51 < CA52 < CA61 < CA62, Condition 3: CA62 < CA72 < CA81 < CA82 < CA91 < CA92, Condition 4: CA31 - CA22 < CA41 - CA32, Condition 5: CA41 + CA42 < CA92, Condition 6: L9R1 + L9R2 < CA92

[0390] The effective diameter of the lens is the smallest for the second lens 112 and the largest for the ninth lens 119. The effective diameter of the fourth surface S4 or the fifth surface S5 can be the smallest, and the effective diameter of the eighteenth surface S18 can be the largest. The size of the effective diameter of the ninth lens 119 is the largest so that it can effectively refract the incident light toward the image sensor 300. Therefore, the optical system 1000 can have improved chromatic aberration control characteristics and can improve the vignetting characteristics of the optical system 1000 by controlling the incident light.

[0391] In the optical system, the number of lenses with a refractive index exceeding 1.60 can be 4 or less and can be less than the number of lenses with a refractive index of 1.60 or less. In the optical system, the number of lenses with a refractive index of 1.60 or less can be 4 or more or 5 or more. Here, the average refractive index of the first lens 111 to the ninth lens 119 can be 1.50 or more. In the optical system, the number of lenses with an Abbe number greater than 45 can be greater than the number of lenses with an Abbe number less than 45 (for example, 5 or more). The average Abbe number of the first lens 111 to the ninth lens 119 can be 40 or more. By setting the refractive index and Abbe number of each lens, the influence of chromatic aberration can be controlled.

[0392] BFL is the optical axis distance between the surface of the image sensor 300 and the eighteenth surface S18 on the sensor side of the ninth lens 119. CT8 is the central thickness of the eighth lens 118, and ET8 is the edge thickness at the end of the effective area of the eighth lens 118. CT9 is the central thickness of the ninth lens 119. CG8 is the optical axis distance between the eighth lens 118 and the ninth lens 119. That is, the optical axis distance CG8 between the eighth lens 118 and the ninth lens 119 is the distance between the sixteenth surface S16 and the seventeenth surface S17 on the optical axis OA. In this way, the central thicknesses of the first to ninth lenses 119 can be defined as CT1 to CT9, and the optical axis distances between the first to ninth lenses can be defined as CG1 to CG8. In addition, the edge thicknesses of the respective lenses can be defined as ET1 to ET9, and the edge distances between adjacent lenses can be defined as EG1 to EG8. Here, the edge thickness and the edge distance can be the distances in the optical axis direction between the effective areas of the respective lenses. CG8 can be greater than the optical axis distance CG2 between the second lens 112 and the third lens 113. CG8 can be greater than the sum of the central thicknesses CT6 and CT8 of the sixth lens 116 and the eighth lens 118. CG8 is the largest among the optical axis distances between two adjacent lenses. CG8 can be 23% or less of the optical axis distance from the first surface S1 of the first lens 11 to the eighteenth surface S18 of the ninth lens 119, for example, in the range of 10% to 23%. Among the first lens 111 to the ninth lens 119, the first lens 111 has the largest central thickness. The central thickness CT1 of the first lens 111 can be greater than the central thicknesses of the eighth lens 118 and the ninth lens 119, and can satisfy the conditions: CT1 < CG8 and CT1 < CG5. By the central thickness CT1 of the first lens 111 and the optical axis distance CG8 between the eighth lens 118 and the ninth lens 119, a thin optical system with improved optical performance can be provided.

[0393] The formula: CG1 < CT2 < CT3 can be satisfied. Therefore, by making the central distance CG1 between the first lens 111 and the second lens 112 less than the central thickness CT2 of the second lens 112, the difference between the effective diameters CA1, CA2, and CA3 can be reduced, and the central distance between the lenses can be reduced. The formula: CA3 - CA2 < CA1 - CA2 can be satisfied.

[0394] The center distance CG8 between the eighth lens 118 and the ninth lens 119 is the largest among the center distances between the lenses, and the optical axis distance CG3 between the third lens 113 and the fourth lens 114 is the smallest among the center distances between the lenses. The lens having the smallest center thickness can be any one of the second lens 112, the fourth lens 114, the fifth lens 115, and the sixth lens 116. For example, the second lens 112.

[0395] Among the lenses 111 to 119, the maximum center thickness can be more than 4 times the minimum center thickness. For example, 1.5 times to 4 times or 3 times to 4 times. Among the above lenses, the number of lenses with a center thickness of 0.60 mm or less can be greater than the number of lenses with a center thickness of 0.6 mm or more, and is more than 5. The average center thickness of the lenses can be less than 0.8 mm. For example, in the range of 0.6 mm to 0.79 mm. The optical system 1000 having an image sensor 300 with a size of about 1 inch can be arranged in a structure with a relatively thin thickness.

[0396] The sum of the center thicknesses CT of the first lens 111 to the ninth lens 119 is ΣCT, and the sum of the center distances CG between the first lens 111 to the ninth lens 119 is ΣCG, and the average center thickness CT of the first lens 111 to the ninth lens 119 is CT_AVER, and any one of the following conditions can be satisfied.

[0397] Condition 1: ΣCT < ΣCG, Condition 2: 0.5 < ΣCG - ΣCT, Condition 3: 0.3 < CT_AVER < 0.9

[0398] By setting the sum ΣCT of the center thicknesses of the first lens 111 to the ninth lens 119 and the sum ΣCG of the center distances between the first lens 111 to the ninth lens 119, the optical system 1000 can control the incident light and has improved aberration characteristics and resolution.

[0399] When the focal lengths of the respective lenses 111 to 119 are defined as F1 to F9, at least one of the following conditions can be satisfied.

[0400] Condition 1: F1 < F3, Condition 2: F5 < F3 < |F4|

[0401] Condition 3: F3 < F8 < F7, Condition 4: F8 < (|F4|) < F7

[0402] By adjusting the focal length, the resolution can be affected. When the focal length is described as an absolute value, the focal length F7 of the seventh lens 117 can be the largest among the lenses, and the focal length of the ninth lens 119 can be the smallest, and the absolute value of the difference between the focal lengths of the eighth lens 118 and the ninth lens 119 can be 50 mm or more. The maximum focal length can be 50 times or more the minimum focal length. The refractive powers of the first lens 111 to the ninth lens 119 can be distributed to minimize chromatic aberration.

[0403] If the refractive indices of the respective lenses 111 to 119 are n1 to n9, and the Abbe numbers of the respective lenses 111 to 119 are v1 to v9, the refractive indices can satisfy the conditions: n1 < n2, and n1, n3, n5, n7, n8, and n9 are 1.6 or less, and the difference between them can be 0.2 or less, and n2, n4, and n6 are greater than 1.60. The Abbe numbers can satisfy the conditions: v2 < v1 and v1, v3, v5, v7, v8, and v9 can be 45 or more, and the difference between them is less than 5, and v2, v4, v6 can be less than 45, for example, 30 or less. Thus, the optical system 1000 can have improved chromatic aberration control characteristics. Preferably, the following condition can be satisfied: v2 * n2 < v1 * n1. To minimize chromatic aberration, the refractive index of the second lens 112 can be set relatively high, and the refractive index of the third lens 113 can be set relatively low. Additionally, to minimize chromatic aberration, the Abbe number v2 of the second lens 112 can be set relatively low, and the Abbe number v3 of the third lens 113 can be set relatively high.

[0404] In addition, the first lens 111 to the ninth lens 119 are made of a plastic material and all have aspherical surfaces, so that spherical aberration and chromatic aberration can be corrected, and lenses with a high Abbe number and lenses with a low refractive index are alternately used. By arranging these, by compensating for chromatic aberration and improving the performance between lenses, a small lens optical system with high resolution can be provided.

[0405] The optical system 1000 according to the second embodiment can satisfy at least one or two of the equations described below. Thus, the optical system 1000 according to the second embodiment has improved optical characteristics. Aberration characteristics such as chromatic aberration and distortion aberration can be effectively controlled, and good optical performance can be achieved even at the center and periphery of the FOV. The optical system 1000 can have improved resolution, and can have a thinner and smaller structure.

[0406] [Equation 1] 1 < CT1 / CT2 < 5

[0407] In Equation 1, when the central thickness CT1 of the first lens 111 and the central thickness CT2 of the second lens 112 are satisfied, the optical system 1000 can improve the aberration characteristics. Preferably, Equation 1 can satisfy: 2.5 < CT1 / CT2 < 4.5.

[0408] [Equation 2] 1 < CT3 / ET3 < 5

[0409] In Equation 2, when the central thickness CT3 of the third lens 113 and the edge thickness ET3 of the fourth lens 104 are satisfied, the optical system 1000 can have improved chromatic aberration control characteristics. Preferably, Equation 2 can satisfy: 1.2 < CT3 / ET3 < 2.5.

[0410] [Equation 2-1] 1 < CT1 / ET1 < 4 [Equation 2-2] 0 < CT2 / ET2 < 1

[0411] [Equation 2-3] 1 < CT3 / ET3 < 4 [Equation 2-4] 0.8 < CT4 / ET4 < 1.8

[0412] [Equation 2-5] 1 < CT5 / ET5 < 4 [Equation 2-6] 0.5 < CT6 / ET6 < 1.5

[0413] [Equation 2-7] 1 < CT7 / ET7 < 5 [Equation 2-8] 0.5 < CT8 / ET8 < 1.5

[0414] [Equation 2-9] 0 < CT9 / ET9 < 1 [Equation 2-10] 0.5 < SD / TD < 1

[0415] If the ratios between the central thicknesses CT2 to CT9 and the edge thicknesses ET2 to ET9 of the second lens 112 to the ninth lens 119 satisfy Equations 2-1 to 2-8, then the optical system 1000 can have improved chromatic aberration control characteristics. In other words, by setting the range of the central thickness based on the edge thickness of each lens 111 to 119 and setting the difference between the outermost thickness and the central thickness of each lens to this range, the distortion aberration can be corrected, and a wide-angle image can be obtained. In addition, the difference between the edge thickness and the central thickness of the first lens 111 is set to be greater than the difference between the outermost thickness and the central thickness of the last lens 119 to correct the distortion aberration of the light traveling to the image sensor 300.

[0416] SD is the optical axis distance from the aperture stop to the eighteenth surface S18 on the sensor side of the ninth lens 119, and TD is the optical axis distance from the first surface S1 on the object side of the first lens 111 to the eighteenth surface S18 on the sensor side of the ninth lens 119. The aperture stop can be disposed around the sensor side surface of the second lens 112. When the optical system 1000 according to the second embodiment satisfies Equation 2-9, the optical system 1000 can correct chromatic aberration.

[0417] [Formula 2-10]0.5<|F_LG1 / F_LG2|<1.5

[0418] 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 second embodiment satisfies Formula 2-10, the optical system 1000 can correct chromatic aberration. That is, when the value of Formula 2-10 is close to 1, distortion aberration can be reduced. Preferably, the condition: 0<|F_LG1-F_LG2|<5 can be satisfied.

[0419] [Formula 3] 18 <TTL / CT_AVER<28

[0420] In Formula 3, CT_AVER is the average value of the center thickness of the first lens 111 to the ninth lens 119, and when the center thickness and TTL of the lens satisfy the above range, a thin optical system can be provided. Preferably, 18 <TTL / CT_AVER<25。

[0421] [Formula 3-1]2 <TTL / CT_AVER / n<3

[0422] In Formula 3-1, n is the total number of lenses, and when the center thickness and TTL of the lenses satisfy the above ranges compared to the number of lenses, a thin optical system can be provided.

[0423] [Formula 3-2] CG5 <CG8

[0424] In Formula 3-2, when the optical axis distance CG5 between the fifth lens 115 and the sixth lens 116 and the optical axis distance CG8 between the seventh lens and the eighth lens satisfy the above ranges, the optical system 1000 has improved chromatic aberration control characteristics.

[0425] [Formula 3-3] CT1+CT2+CT3+CT4 <CG5+CG8

[0426] In Formula 3-3, when the sum of the center thicknesses CT1, CT2, CT3, and CT4 of the first lens 111, the second lens 112, the third lens 113, and the fourth lens 114 is less than the sum of the optical axis distance CG5 between the fifth lens 115 and the sixth lens 116 and the optical axis distance CG8 between the eighth lens 118 and the ninth lens 119, the optical system 1000 can have improved chromatic aberration control characteristics. In addition, by reducing the thickness of each lens, a thin optical system can be provided. In addition, by reducing the thickness of each lens in Formulas 3 to 3-3 and the distance between adjacent lenses, a thin optical system can be provided.

[0427] [Equation 4] 1.60 <n2

[0428] In Equation 4, n2 represents the refractive index at the d-line of the second lens 112. When the optical system 1000 according to the second embodiment satisfies Equation 4, the optical system 1000 can improve chromatic aberration characteristics.

[0429] [Equation 4-1] 1.50 < n1 < 1.60, 1.50 < n3 < 1.60, 1.60 < n4 < 1.70, 1.50 < n5 < 1.60

[0430] In Equation 4-1, n1, n3, n4, and n5 are the refractive indices at the d-line of the first lens 111, the third lens 113, the fourth lens 114, and the fifth lens 115, respectively. When the optical system 1000 according to the second embodiment satisfies Equation 4-1, the influence on the TTL of the optical system 1000 can be suppressed.

[0431] [Equation 4-2] 0 ≤ |n7 - n8| ≤ 0.05, 0 ≤ |n8 - n9| ≤ 0.05

[0432] In Equation 4-2, n7, n8, and n9 are the refractive indices at the d-line of the seventh lens 117, the eighth lens 118, and the ninth lens 119, respectively. When the optical system 1000 according to the second embodiment satisfies Equation 4-2, the optical system 1000 can improve chromatic aberration characteristics.

[0433] [Equation 5] 0.8 < Max_Sag92 to sensor < 1.8

[0434] In Equation 5, Max_Sag92_to_sensor represents the distance in the optical axis direction from the maximum indentation value of the eighteenth surface S18 on the sensor side of the ninth lens 119 to the image sensor 300. Max_Sag92 is the maximum separation distance from the straight line that extends perpendicularly to the optical axis from the center of the eighteenth surface S18 on the sensor side of the ninth lens 119 to the eighteenth surface S18. It can have a positive value when it is on the sensor side compared to the straight line and a negative value when it is on the object side compared to the straight line. For example, Max_Sag92_to_sensor represents the distance in the optical axis direction from the fourth critical point P4 on the sensor side surface of the ninth lens 119 to the image sensor 300. When the optical system 1000 according to the second embodiment satisfies Equation 5, the optical system 1000 ensures that the filter 500 can be placed in the space between the lens 100A and the image sensor 300, thereby having improved assembly performance. In addition, when the optical system 1000 satisfies Equation 5, the optical system 1000 can ensure the distance for module manufacturing. Preferably, the value of Equation 5 can satisfy: 1.2 < Max_Sag92_to_sensor < 1.6. In the lens data of the second embodiment, the position of the filter 500, the specific distance between the last lens and the filter 500, and the distance between the image sensor 300 and the filter 500 are positions set for the convenience of designing the optical system 1000, and the filter 500 can be freely set within the range where it does not contact the last lens and the image sensor 300. Therefore, in the lens data, the value of Max_Sag92_to_sensor 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 it does not contact the last lens and the image sensor 300 respectively to have good optical performance.

[0435] [Equation 6] 0.8 < BFL / Max_Sag92_to_sensor < 2

[0436] In Equation 6, the back focal length (BFL) represents the distance (mm) on the optical axis OA from the center of the eighteenth surface S18 of the ninth lens 119 to the imaging surface of the image sensor 300. When the optical system 1000 according to the second embodiment satisfies Equation 6, the optical system 1000 can improve the distortion aberration characteristics and has good optical performance in the peripheral part of the FOV. Equation 6 can satisfy the following condition: BFL > Max_Sag92_to_sensor.

[0437] [Equation 7] 5 < |L9S2_Max slope| < 65

[0438] In Formula 7, L9S2_Max slope represents the maximum value (degree) of the tangent angle measured on the sensor-side eighteenth surface S18 of the ninth lens 119. Specifically, on the eighteenth surface S18, L9S2_Max slope represents the maximum value (degree) of the tangent angle measured on the sensor-side eighteenth surface S18. Specifically, on the eighteenth surface S18, L9S2_Max slope represents the normal K2 (see FIG. 14 ) perpendicular to the tangent line passing through any point of the eighteenth surface S18 and the optical axis OA. Fig.11 ) is the value of the maximum angle θ2. When the optical system 1000 according to the second embodiment satisfies Formula 7, the optical system 1000 can control the occurrence of lens glare. Preferably, Formula 7 can satisfy: 21≤|L9S2_Max slope|≤40.

[0439] [Equation 8] CT1<|Max_Sag91|

[0440] In Formula 8, Max_Sag91 is the maximum distance value from a straight line extending in directions X and Y perpendicular to the center of the object-side surface of the ninth lens 119 to the seventeenth surface S17 in the optical axis direction, and CT1 is the center thickness of the first lens. When Formula 8 is satisfied, the optical system 1000 can increase the height of the outside of the effective area of ​​the object-side surface of the ninth lens 119 compared to the center thickness of the first lens 111 having the maximum center thickness. Therefore, the ninth lens 119 has a maximum effective diameter and can refract incident light toward the image sensor 300. When the optical system 1000 according to the second embodiment satisfies Formula 8, the size of the image sensor 300 can be increased compared to the TTL of the optical system 1000, and a thin optical system can be provided. Preferably, the following condition can be satisfied: 2<|Max_Sag91|<3.5. The outside of the effective area of ​​the object-side surface or the sensor-side surface of each lens may include an edge.

[0441] [Formula 8-1]CG7<|Max_Sag92|

[0442] In Formula 8-1, Max_Sag92 is the maximum distance value in the optical axis direction from a straight line extending in directions X and Y perpendicular to the center of the sensor-side surface of the ninth lens 119 to the edge of the eighteenth surface S18. When Formula 8-1 is satisfied, the optical system 1000 can set the maximum height of the outer effective area of ​​the sensor-side surface of the ninth lens 119 to be greater than the center distance CG7 between the seventh lens 117 and the eighth lens 118. Therefore, the sensor-side surface of the ninth lens 119 can guide the light refracted to the outside of the second critical point P2 of the eighth lens 118. Therefore, the ninth lens 119 has a maximum effective diameter and can refract the incident light toward the image sensor 300. When the optical system 1000 according to the second embodiment satisfies Formula 8-1, the size of the image sensor 300 can be increased compared to the TTL of the optical system 1000, and a thin optical system can be provided. Preferably, the following condition can be satisfied: |Max_Sag92|<|Max_Sag91|.

[0443] [Equation 9] CG2<|Max_Sag81| <CG5

[0444] In Formula 9, Max_Sag81 is the maximum distance value in the vertical direction from a straight line extending in directions X and Y perpendicular to the center of the object-side surface of the eighth lens 118 to the edge of the sixteenth surface S16, CG2 is the optical axis distance between the second lens and the third lens, and CG5 is the optical axis distance between the fifth lens and the sixth lens. When Formula 9 is satisfied, the optical system 1000 can be arranged so that the outside of the effective area of ​​the object-side surface of the eighth lens 118 is further outward than the edges of the sixth lens 116 and the seventh lens 117. Therefore, the eighth lens 118 can refract light incident from the outside of the seventh lens 117 toward the ninth lens 119. When the optical system 1000 according to the second embodiment satisfies Formula 9, the size of the image sensor 300 can be increased compared to the TTL of the optical system 1000, thereby providing a thin optical system. When the optical system 1000 satisfies Formulas 8 and 9, the optical system 1000 can improve the distortion aberration characteristics and have good optical performance in the peripheral portion of the FOV. Preferably, the following condition may be satisfied: |Max_Sag82|<|Max_Sag91|. In addition, the following condition may be satisfied: (CT1+CT2)<|Max_Sag91|<(CT1*3).

[0445] [Formula 9-1] CT2 <CG2

[0446] [Formula 9-2] |CT1-CG2|<0.5

[0447] In formulas 9-1 and 9-2, CT3 is the center thickness of the third lens, CG2 is the center distance between the second lens and the third lens, and when this condition is met, the size of the lens can be controlled relative to the boundary between the first lens group LG1 and the second lens group LG2, and the factors affecting the distortion aberration can be controlled.

[0448] [Formula 10] <CG8 / EG8<10

[0449] In Formula 10, when the optical axis distance CG8 between the eighth lens 118 and the ninth lens 119 and the optical axis distance EG8 at the end of the effective area between the eighth lens 118 and the ninth lens 119 are satisfied, good optical performance can be achieved even in the center and peripheral portions of the FOV. In addition, the optical system 1000 can reduce distortion and have improved optical performance. Preferably, Formula 10 can satisfy: 2 <CG8 / EG8<5。

[0450] [Equation 11] <CG8 / CG5<3

[0451] In Formula 11, when the optical axis distance CG5 between the fifth lens 115 and the sixth lens 116 and the optical axis distance CG8 between the eighth lens 118 and the ninth lens 119 are satisfied, the optical system 1000 can improve the aberration characteristics and control the size of the optical system 1000, for example, reduce the TTL. Preferably, Formula 11 can satisfy: 1.3 <CG8 / CG5<2。

[0452] [Equation 12] <CT1 / CT8<3

[0453] In Formula 12, when the center thickness CT1 of the first lens 111 and the center thickness CT8 of the eighth lens 118 are satisfied, the optical system 1000 may have improved aberration characteristics. In addition, the optical system 1000 has good optical performance at a set FOV and can control TTL. Preferably, Formula 12 may satisfy: 1.5 <CT1 / CT8<2.5。

[0454] [Equation 13] <CT7 / CT8<3

[0455] In Formula 13, when the center thickness CT7 of the seventh lens 117 and the center thickness CT8 of the eighth lens 118 are satisfied, the optical system 1000 includes the seventh lens 117 and the eighth lens 118. The manufacturing accuracy of the lens 118 can be relaxed, and the optical performance of the central part and the peripheral part of the FOV can be improved. Preferably, Formula 13 can satisfy: 1 <CT7 / CT8<2。

[0456] [Equation 14] <L8R2 / L9R1<20

[0457] In Formula 14, L8R2 represents the curvature radius (mm) of the sixteenth surface S16 of the eighth lens 118 on the optical axis, and L9R1 represents the curvature radius (mm) of the seventeenth surface S17 of the ninth lens 119 on the optical axis. When the optical system 1000 according to the second embodiment satisfies Formula 14, the aberration characteristics of the optical system 1000 can be improved. Preferably, Formula 14 can satisfy: <L8R2 / L9R1<1.5。

[0458] [Formula 15] 0<(CG8-EG8) / CG8<1

[0459] If Formula 15 satisfies the center distance CG8 and the edge distance EG8 between the eighth lens 118 and the ninth lens 119, the optical system 1000 can reduce the occurrence of distortion and have improved optical performance. In addition, by reducing the edge distance between the eighth lens 118 and the ninth lens 119 compared to the center distance, the height of the outer portion of the ninth lens 119 can be increased. When the optical system 1000 according to the second embodiment satisfies Formula 15, the optical performance of the central portion and the peripheral portion of the FOV can be improved. Preferably, Formula 15 can satisfy the condition: 0.5<(CG8-EG8) / (CG8)<1.

[0460] [Equation 16] <CA11 / CA22<2

[0461] In Formula 16, CA11 represents an effective diameter (clear aperture, CA) of the first surface S1 of the first lens 111, and CA22 represents an effective diameter of the fourth surface S4 of the second lens 112. When the optical system 1000 according to the second embodiment satisfies Formula 16, the optical system 1000 can control the light path incident to and emitted from the first lens group LG1, and has improved aberration control characteristics. Preferably, Formula 16 can satisfy: 1 <CA11 / CA22<1.5。

[0462] [Formula 17]1 <CA82 / CA31<5

[0463] In Formula 17, CA31 represents the effective diameter of the fifth surface S5 of the third lens 113, and CA82 represents the effective diameter of the sixteenth surface S16 of the eighth lens 118. When the optical system 1000 according to the second embodiment satisfies Formula 17, the optical system 1000 can control the light path incident on the second lens group LG2 and improve the aberration characteristics. Preferably, Formula 17 can satisfy: <CA82 / CA31<3。

[0464] [Equation 18] 0.5 <CA22 / CA31<1.5

[0465] In Formula 18, when the effective diameter CA22 of the fourth surface S4 of the second lens 112 and the effective diameter CA31 of the fifth surface S5 of the third lens 113 are satisfied, the difference in effective diameter between the first lens group LG1 and the second lens group LG2 can be reduced, and light loss can be suppressed. In addition, the optical system 1000 can improve chromatic aberration and control vignetting of optical performance. Preferably, Formula 18 can satisfy: 0.7 <CA22 / CA31<1.2。

[0466] [Equation 19] 0.1 <CA52 / CA82<1

[0467] In Formula 19, when the effective diameter CA52 of the tenth surface S10 of the fifth lens 115 and the effective diameter CA82 of the sixteenth surface S16 of the eighth lens 118 are satisfied, the optical path to the second lens group LG2 can be set. In addition, the optical system 1000 can improve chromatic aberration. Preferably, Formula 19 can satisfy: 0.4 <CA52 / CA82≤0.9。

[0468] [Formula 20]1 <CA92 / CA11<5

[0469] In Formula 20, when the effective diameter CA91 of the eighteenth surface S18 of the ninth lens 119 and the effective diameter CA11 of the first surface S1 of the first lens 111 are satisfied, the effective diameter and the optical path between the incident side lens and the last lens can be set. Therefore, the optical system 1000 can set the FOV and the size of the optical system. Preferably, Formula 20 can satisfy: 2 <CA92 / CA11<3.5。

[0470] [Formula 20-1]3 <CA92 / CG8<15

[0471] In Formula 20-1, CA92 is the effective diameter of the largest lens surface, and is the effective diameter of the eighteenth surface S18 of the ninth lens 119. When the optical system 1000 according to the second embodiment satisfies Formula 20-1, the optical system 1000 can improve the aberration characteristics and control TTL reduction. Preferably, Formula 20-1 can satisfy: 3 <CA92 / CG8<10。

[0472] [Formula 20-2]3 <CA82 / CG8<15

[0473] Formula 20-2 can set the effective diameter CA82 of the sixteenth surface S16 of the eighth lens 118 and the optical axis distance CG8 between the eighth lens 118 and the ninth lens 119. When the optical system 1000 according to the second embodiment satisfies Formula 20-2, the optical system 1000 can improve the aberration characteristics and control the TTL to be reduced. Preferably, Formula 20-2 can satisfy: <CA82 / CG8<7。

[0474] [Equation 21] 1 < CG2 / EG2 < 10

[0475] In Equation 21, when the optical axis distance CG2 and the marginal distance EG3 between the second lens 112 and the third lens 113 are satisfied, the optical system 1000 can reduce chromatic aberration, improve aberration characteristics, and control vignetting of optical performance. Additionally, by designing the marginal distance between the second lens 112 and the third lens 113 to be less than the central distance, distortion aberration can be corrected. Preferably, Equation 21 can satisfy: 3 < CG2 / EG2 < 8. Additionally, the condition: 35 < (CG2 / EG2) * n < 60 can be satisfied, where n is the total number of lenses.

[0476] [Equation 22] 0 < CG7 / EG7 < 2

[0477] In Equation 22, when the optical axis distance CG7 and the marginal distance EG7 between the seventh lens 117 and the eighth lens 118 are satisfied, the optical system can have good optical performance even at the center and periphery of the FOV. Additionally, by designing the marginal distance between the seventh lens 117 and the eighth lens 118 to be less than the central distance, distortion aberration can be compensated. Preferably, the condition: 0 < CG7 / EG7 < 1 can be satisfied. At least one of Equation 21 and Equation 22 may further include at least one of Equations 22-1 to 22-7.

[0478] [Equation 22-1] 0.2 < CG1 / EG1 < 1 [Equation 22-2] 0 < CG3 / EG3 < 0.5

[0479] [Equation 22-3] 0 < CG4 / EG4 < 1 [Equation 22-4] 3 < CG5 / EG5 < 8

[0480] [Equation 22-5] 0.5 < CG6 / EG6 < 2 [Equation 22-6] 1 < CG8 / EG8 < 5

[0481] [Equation 22-7] 18 < (CG8 / EG8) * n < 40, where n is the total number of lenses

[0482] By setting the effective diameter of each lens and the central distance and marginal distance between adjacent lenses using Equations 16 to 22, the optical path in the center and outer periphery of the optical system 1000 can be adjusted. Therefore, the optical system can have good optical performance even at the center and periphery of the FOV, and the occurrence of distortion can be suppressed.

[0483] [Equation 23] 0 < G8_Max / CG8 < 2

[0484] In Equation 23, G8_Max represents the maximum distance (mm) between the eighth lens 118 and the ninth lens 119. When the optical system 1000 according to the second embodiment satisfies Equation 23, the optical performance in the peripheral part of the FOV can be improved, and the distortion of the aberration characteristics can be suppressed. Preferably, G8_Max and CG8 in Equation 23 can be the same.

[0485] [Equation 24] 0 < CT7 / CG8 < 1

[0486] In Equation 24, when the central thickness CT7 of the seventh lens 117 and the optical axis distance CG8 between the eighth lens 118 and the ninth lens 119 are satisfied, the optical system 1000 is located between the eighth lens and the ninth lens. The optical axis distance CG8 and the central thickness of the seventh lens 117 can be set, and the optical performance in the peripheral part of the FOV can be improved. Preferably, Equation 24 can satisfy: 0 < CT7 / CG8 < 0.5.

[0487] [Equation 25] 1 < CG8 / CT8 < 7

[0488] In Equation 25, when the central thickness CT8 of the eighth lens 118 and the optical axis distance CG8 between the eighth lens 118 and the ninth lens 119 are satisfied, the optical system 1000 is configured to use the eighth lens and the ninth lens. The effective diameter size and the distance can be reduced, and the optical performance in the peripheral part of the FOV can be improved. Preferably, Equation 25 can satisfy: 3 < CG8 / CT8 < 6.

[0489] [Equation 26] 2 < CG8 / CT9 < 6

[0490] In Equation 26, when the central thickness CT9 of the ninth lens 119 and the optical axis distance CG8 between the eighth lens 118 and the ninth lens 119 are satisfied, the optical system 1000 has the effective diameter of the ninth lens. The size and the optical axis distance between the eighth lens and the ninth lens can be reduced, and the optical performance in the peripheral part of the FOV can be improved. Preferably, Equation 26 can satisfy: 3 < CG8 / CT9 < 5.5.

[0491] [Equation 27] 1 < L5R2 / CT5 < 100

[0492] In Equation 27, when the radius of curvature L5R2 of the tenth surface S10 of the fifth lens 115 and the central thickness CT5 of the fifth lens 115 are satisfied, the optical system 1000 can control the refractive power of the fifth lens 115 and improve the optical performance of the light incident on the second lens group LG2. Preferably, Equation 27 can satisfy: 10 < L5R2 / CT5 < 30. Preferably, the condition: L5R2 > 0 can be satisfied.

[0493] [Equation 28] 0 < L5R1 / L8R1 < 10

[0494] In Equation 28, when the radius of curvature L5R1 of the ninth surface S9 of the fifth lens 115 and the radius of curvature L8R1 of the fifteenth surface S15 of the eighth lens 118 are satisfied, the optical performance can be improved by controlling the shapes and refractive powers of the fifth lens and the eighth lens, and the optical performance of the second lens group LG2 can be improved. Preferably, Equation 28 can satisfy: 0 < L5R1 / L8R1 < 1. Additionally, the conditions: L5R1 > 0 and L8R1 > 0 can be satisfied.

[0495] [Equation 29] 0 < L1R1 / L1R2 < 1

[0496] Equation 29 can set the radius of curvature L1R1 and L1R2 of the first surface S1 and the second surface S2 on the object side of the first lens 111, and when these conditions are satisfied, the lens size and resolution can be set. Preferably, Equation 29 can satisfy: 0 < L1R1 / L1R2 < 0.5. Preferably, L1R1 > 0 and L1R2 > 0 can be satisfied.

[0497] [Equation 30] 0 < L2R2 / L2R1 < 5

[0498] Equation 30 can set the radius of curvature L2R1 and L2R2 of the third surface S3 and the fourth surface S4 on the object side of the second lens 112, and when these conditions are satisfied, the resolution of the lens can be determined. Preferably, Equation 30 can satisfy: 0 < L2R2 / L2R1 < 1. Preferably, L2R1 > 0 and L2R2 > 0 can be satisfied. At least one of Equation 28, Equation 29, and Equation 30 can include the following Equation 30-1 to 30-6, and the resolution of each lens can be determined.

[0499] [Equation 30-1] 1 < L3R1 / L3R2 < 20 and 5 < L3R1 / L3R2 < 15 (However, L3R1, L3R2 < 0)

[0500] [Equation 30-2] 0 < L4R1 / L4R2 < 2

[0501] [Equation 30-3] Satisfy the following condition: 0 < L5R1 / L5R2 < 2, preferably, the following condition can be satisfied: 0 < L5R1 / L5R2 < 1.

[0502] [Equation 30-4] Satisfy the condition: 0 < L6R1 / L6R2 < 3, preferably, the following condition can be satisfied: 1 < L6R1 / L6R2 < 2. However, L6R1, L6R2 < 0.

[0503] [Equation 30-5] 0 < L8R1 / L8R2 < 1.5 or 0 < L8R1 / L8R2 < 1

[0504] [Formula 30-6]1 <L9R2 / L9R1<5

[0505] By setting the center distance and edge distance between two adjacent lenses to the above ranges using Expression 30 and Expression 30-1 to Expression 30-6, distortion aberration of aberration characteristics can be corrected.

[0506] [Equation 31] <CT_Max / CG_Max<2

[0507] In Formula 31, when the center thickness of each lens satisfies the maximum thickness CT_Max and the maximum value CG_Max of the air gap or the distance on the optical axis between the multiple lenses, the optical system 1000 has good optical performance under the set FOV and focal length, and the size of the optical system 1000 can be reduced, for example, the TTL can be reduced. Preferably, Formula 31 can satisfy: <CT_Max / CG_Max<1。

[0508] [Equation 32] 0<ΣCT / ΣCG<2

[0509] In Formula 32, ΣCT represents the sum of the center thickness (mm) of each of the plurality of lenses, and ΣCG represents the sum of the distances (mm) on the optical axis OA between two adjacent lenses of the plurality of lenses. When the optical system 1000 according to the second embodiment satisfies Formula 32, the optical system 1000 has good optical performance at a set FOV and focal length, and the size of the optical system 1000 can be reduced, for example, TTL can be reduced. Preferably, Formula 32 can satisfy: 0.5<ΣCT / ΣCG<1.2. Therefore, the optical system can be designed to reduce the center thickness of each lens and increase the distance between adjacent lenses.

[0510] [Equation 33] 10<∑Index<20

[0511] In Formula 33, ∑Index represents the sum of the refractive index of each of the plurality of lenses at the d-line. When the optical system 1000 according to the second embodiment satisfies Formula 33, the TTL of the optical system 1000 can be controlled, and improved resolution can be achieved. In addition, Formula 33 can satisfy the conditions: 12<∑Index<16 and 100<∑Index*n, where n is the total number of lenses.

[0512] [Equation 34] 10<∑Abb / ∑Index<50

[0513] In Formula 34, ∑Abb represents the sum of the Abbe numbers of each of the plurality of lenses. When the optical system 1000 according to the second embodiment satisfies Formula 34, the optical system 1000 may have improved aberration characteristics and resolution. Preferably, Formula 34 may satisfy: 20<∑Abb / ∑Index<40. Preferably, the condition: 360<(∑Abb-∑Index) may be satisfied.

[0514] [Equation 35] 0<|Max_Distortion|<5

[0515] In Formula 35, Max_Distortion represents the maximum value of the distortion in the area 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 second embodiment satisfies Formula 35, the optical system 1000 can improve the distortion characteristics. Preferably, Formula 35 can satisfy: 1<|Max_Distortion|<3.

[0516] [Equation 36] <EG_Max / CT_Max<3

[0517] In Formula 36, ​​CT_Max represents the thickest thickness (mm) among the center thicknesses of each of the plurality of lenses, and EG_Max is the maximum distance on the edge side between two adjacent lenses. When the optical system 1000 according to the second embodiment satisfies Formula 36, ​​the optical system 1000 has a set FOV and focal length, and can have good optical performance in the peripheral portion of the FOV. Preferably, Formula 36 can satisfy: <EG_Max / CT_Max<1。

[0518] [Equation 37] 0.5 <CA11 / CA_Min<2

[0519] In Formula 37, when the effective diameter CA11 of the first surface S1 of the first lens 111 and the minimum effective diameter CA_Min of the lens surface are satisfied, the amount of light incident through the first lens 111 can be controlled, and a thin optical system can be provided while maintaining optical performance. Preferably, Formula 37 can satisfy: 1 <CA11 / CA_Min<1.5。

[0520] [Formula 38]1 <CA_Max / CA_Min<5

[0521] In Formula 38, CA_Max represents the maximum effective diameter among the object-side surface and the sensor-side surface of the plurality of lenses and the maximum effective diameter (mm) among the effective diameters (mm) of the first surface S1 to the eighteenth surface S18. When the optical system 1000 according to the second embodiment satisfies Formula 38, the optical system 1000 can provide a thin and compact optical system while maintaining optical performance. Preferably, Formula 38 can satisfy: 2 <CA_Max / CA_Min<4.5。

[0522] [Formula 39]1 <CA_Max / CA_AVR<3

[0523] In Formula 39, the maximum effective diameter CA_Max and the average effective diameter CA_AVR are set among the object-side surface and the sensor-side surface of the plurality of lenses. When these conditions are met, a thin and compact optical system can be provided. Preferably, Formula 39 can satisfy: 1 <CA_Max / CA_AVR<2.5。

[0524] [Equation 40] 0.1 <CA_Min / CA_AVR<1

[0525] In equation 40, the minimum effective diameter CA_Min and the average effective diameter CA_AVR can be set among the object-side surface and the sensor-side surface of the plurality of lenses, and when this condition is satisfied, a thin and compact optical system can be provided. Preferably, equation 40 can satisfy: 0.3 <CA_Min / CA_AVR<0.9。

[0526] [Equation 41] 0.1 <CA_Max / (2*ImgH)<1

[0527] In Formula 41, the maximum effective diameter CA_Max among the object side surface and the sensor side surface of the plurality of lenses and the distance (ImgH) from the center (0.0F) to the diagonal end (1.0F) of the image sensor 300 are set. When this condition is met, the optical system 1000 has good optical performance in the central and peripheral parts of the FOV, and a thin and compact optical system can be provided. Here, ImgH can be in the range of 4mm to 15mm or 10mm to 15mm. Preferably, Formula 41 can satisfy: 0.5≤CA_Max / (2*ImgH)<1. Here, the following condition can be satisfied: ImgH <TTL<CA_Max<(2*ImgH)。

[0528] [Equation 42] 0.1 <TD / CA_Max<1.5

[0529] In Formula 42, TD is the maximum optical axis distance (mm) from the object-side surface of the first lens to the sensor-side surface of the last lens. For example, TD is the distance from the first surface S1 of the first lens 111 to the eighteenth surface S18 of the ninth lens 119 on the optical axis OA. When the optical system 1000 according to the second embodiment satisfies Formula 42, a thin and compact optical system can be provided. Preferably, Formula 42 can satisfy: 0.5 <TD / CA_Max<1。

[0530] [Formula 43] <F / L8R2<5

[0531] In Formula 43, the total effective focal length F of the optical system 1000 and the curvature radius L8R2 of the sixteenth surface S16 of the eighth lens 118 may be set. When these conditions are met, the optical system 1000 may reduce the size of the optical system 1000, for example, reduce the TTL. Preferably, Formula 43 may satisfy: 1 <F / L8R2<2。

[0532] Formula 43 may further include the following Formula 43-1.

[0533] [Formula 43-1]2 <F / F#<8

[0534] F# can represent the F number. Preferably, formula 43-1 can satisfy: 3 <F / F#<8。

[0535] [Formula 43-2]1 <F / L9R2<5

[0536] Formula 43-2 can set the total effective focal length F of the optical system 1000 and the curvature radius L9R2 of the eighteenth surface S18 of the ninth lens 119. Preferably, Formula 43-2 can satisfy: <F / L9R2<4.5。

[0537] [Formula 44]1 <F / L1R1<10

[0538] In Formula 44, the curvature radius L1R1 of the first surface S1 of the first lens S1 and the total effective focal length F can be set, and when this condition is satisfied, the size of the optical system 1000 can be reduced, for example, the TTL can be reduced. Preferably, Formula 44 can satisfy: 1 <F / L1R1<5。

[0539] [Formula 45]0 <EPD / L9R2<5

[0540] In Formula 45, EPD represents the size (mm) of the entrance pupil diameter of the optical system 1000, and L9R2 represents the radius of curvature (mm) of the eighteenth surface S18 of the ninth lens 119. When the optical system 1000 according to the second embodiment satisfies Formula 45, the optical system 1000 can control the total brightness and have good optical performance in the central part and the peripheral part of the FOV. Preferably, Formula 45 can satisfy: 1 <EPD / L9R2<3。

[0541] Formula 45 may further include the following Formula 45-1.

[0542] [Formula 45-1]2 <EPD / F#<4

[0543] [Equation 46] 0.5 <EPD / L1R1<8

[0544] Formula 46 represents the relationship between the size of the incident pupil diameter of the optical system and the curvature radius of the first surface S1 of the first lens 111, and can control the incident light. Preferably, Formula 46 can satisfy: 0.5 <EPD / L1R1<1.5。

[0545] [Equation 47] 0<|F1 / F2|<2

[0546] In Formula 47, the focal lengths F1 and F2 of the first lens 111 and the second lens 112 may be set. Therefore, the resolution may be improved by adjusting the refractive power of the incident light of the first lens 111 and the second lens 112, and the TTL may be controlled. Preferably, Formula 47 may satisfy: 0<|F1 / F2|<1, and may satisfy the conditions: F1>0 and F2<0.

[0547] [Formula 48] <F12 / F<5

[0548] By setting the combined focal length F12 of the first lens and the second lens and the total focal length F in Formula 48, the optical system 1000 can improve the resolution by adjusting the refractive power of the incident light, and the optical system 1000 can control the TTL. Preferably, Formula 48 can satisfy: 1 <F12 / F<3。

[0549] [Equation 49] 0<|F39 / F12|<2

[0550] In Equation 49, the combined focal length F12 of the first lens and the second lens, i.e., the focal length (mm) of the first lens group, can be set; and the combined focal length F39 of the third lens to the ninth lens, i.e., the focal length of the second lens group; and when the above conditions are satisfied, the refractive power of the first lens group and the refractive power of the second lens group can be controlled to improve the resolution, and the optical system can be set to a thin and compact size. In addition, when Equation 49 is satisfied, the optical system 1000 can improve aberration characteristics, such as chromatic aberration and distortion aberration. Preferably, Equation 49 can be satisfied: 0.5 < F39 / F12 < 1.5. Here, the following conditions can be satisfied: F12 > 0 and F39 > 0.

[0551] [Equation 49-1] F13 < |F49|

[0552] In Equation 49-1, F13 is the combined focal length of the first lens to the third lens and can have a positive refractive power, and F49 is the combined focal length of the fourth lens to the ninth lens and can have a negative refractive power. When Equation 49-1 is satisfied, the optical system 1000 can improve aberration characteristics, such as chromatic aberration and distortion aberration.

[0553] [Equation 50] 0 < F1 / F < 3

[0554] In Equation 50, the total focal length F and the focal length F1 of the first lens 111 can be set, and the resolution can be improved. Equation 50 can be satisfied: 0 < F1 / F < 2, and the following conditions are satisfied: F > 0.

[0555] [Equation 50-1] 0 < |F2| / F < 5 (where F2 < 0)

[0556] [Equation 50-2] 1 < |F3 / F2| < 10 (where F3 > 0)

[0557] [Equation 50-3] 5 < |F4 / F| < 20 (where F4 < 0)

[0558] [Equation 50-4] 1 < F5 / F < 10 (where F5 > 0)

[0559] [Equation 50-5] 5 < F6 / F < 20 (where F6 > 0)

[0560] [Equation 50-6] 10 < F7 / F < 30 (where F7 > 0)

[0561] [Equation 50-7] 5 < F8 / F < 20 (where F8 > 0)

[0562] [Equation 50-8] 0 < |F9| / F < 1.5 (where F9 < 0)

[0563] In Formulas 50-1 to 50-8, F3, F4, F5, F6, F7, F8, and F9 represent the focal lengths (mm) of the third lens 113, the fourth lens 114, the fifth lens 115, the sixth lens 116, the seventh lens 117, the eighth lens 118, and the ninth lens 119, respectively. When this condition is satisfied, the resolution can be improved by controlling the refractive power of each lens, and the optical system can be set to a thin and compact size. The focal lengths of the respective lenses can be distributed to advantageously correct chromatic aberration.

[0564] [Formula 51] 0 < F1 / F12 < 2

[0565] In Formula 51, the resolution of the first lens group can be adjusted by setting the focal length F1 of the first lens and the combined focal length F12 of the first lens and the second lens. Preferably, the condition: 10 < F12 - F1 < 20 can be satisfied.

[0566] [Formula 52] 0 < |F1 / F39| < 2

[0567] By setting the focal length F1 of the first lens and the combined focal length F39 of the third lens to the ninth lens in Formula 52, the size and resolution of the optical system can be adjusted. Preferably, Formula 52 can satisfy: 0 < F1 / F39 < 1.

[0568] [Formula 53] 0 < F1 / F4 < 1

[0569] By setting the focal length F1 of the first lens and the focal length F4 of the fourth lens in Formula 53, the refractive power of the light incident on the first lens group and the second lens group can be controlled, and the size and resolution of the optical system can be adjusted. Preferably, Formula 53 can satisfy: 0 < F1 / F4 < 0.5.

[0570] [Formula 54] 2 mm < TTL < 20 mm

[0571] In Formula 54, TTL represents the distance (mm) from the vertex of the first surface S1 of the first lens 111 to the imaging surface of the image sensor 300 on the optical axis OA. Preferably, Formula 54 can satisfy: 10 < TTL < 20, and thus a thin and compact optical system can be provided.

[0572] [Formula 55] 6 mm < ImgH

[0573] Formula 55 sets the diagonal size (2 * ImgH) of the image sensor 300 to be more than 6 mm, thereby providing an optical system with high resolution. Preferably, Formula 55 can satisfy: 8 ≤ ImgH ≤ 15 or 8 ≤ ImgH ≤ 14. Formula 55 can include at least one of the following Formulas 55-1 to 55-4.

[0574] [Equation 55-1] 0<∑CT / ImgH<1

[0575] [Equation 55-2] 0<∑CT / ImgH<1

[0576] [Equation 55-3]1<∑Index / ImgH<3

[0577] [Formula 55-4] 20<∑Abbe / ImgH<50

[0578] [Equation 55-5](∑CT / n)>(∑CT / ImgH)

[0579] [Equation 55-6](∑CG / n)>(∑CG / ImgH)

[0580] [Equation 55-7](∑Index / n)>(∑Index / ImgH)

[0581] [Equation 55-8](∑Abbe / n)>(∑Abbe / ImgH)

[0582] Formulas 55-1 to 55-8 establish the relationship between ImgH and the sum of the center thicknesses of all lenses, the sum of the center distances between lenses, the sum of the refractive powers of all lenses, the sum of the Abbe numbers of all lenses, and the total number of lenses. Therefore, the resolution and size of an optical system equipped with an image sensor having a diagonal length greater than 12 mm or greater than 16 mm can be adjusted.

[0583] [Formula 56] BFL < 2.5 mm

[0584] Formula 56 shows that by setting the BFL to be less than 2.5 mm, the installation space of the filter 500 can be ensured, the assembly of the components can be improved by the distance between the image sensor 300 and the last lens, and the bonding reliability can be improved. Preferably, Formula 56 can satisfy: 1 <BFL<2。

[0585] [Formula 57] 2mm <F<20mm

[0586] In equation 57, the total focal length F can be set to be suitable for the optical system, preferably, it can satisfy: 5mm <F<15mm。

[0587] [Equation 58] FOV < 120 degrees

[0588] In Formula 58, FOV represents the field of view (degrees) of the optical system 1000, and an optical system of less than 120 degrees may be provided. The FOV may be 70 degrees or more, for example, in the range of 70 degrees to 100 degrees.

[0589] [Equation 59] 0.1 <TTL / CA_Max<2

[0590] By setting the maximum effective diameter CA_Max and TTL among the object-side surface and the sensor-side surface of multiple lenses in Equation 59, a thin and compact optical system can be provided. Preferably, Equation 59 can satisfy: 0.5 < TTL / CA_Max < 1.

[0591] [Equation 60] 0.5 < TTL / ImgH < 3

[0592] Equation 60 can set the total optical axis length (TTL) of the optical system and the diagonal length (ImgH) of the optical axis of the image sensor 300. When the optical system 1000 according to the second embodiment satisfies Equation 60, the optical system 1000 includes a relatively large image sensor 300. For example, the BFL for an application of a large image sensor 300 of about 1-inch size, and can have a smaller TTL, thereby achieving high-definition image quality and a thin structure. Preferably, Equation 60 can satisfy: 1 < TTL / ImgH < 1.5. Preferably, the condition: 150 < TTL * ImgH < 250 can be satisfied.

[0593] [Equation 61] 0.01 < BFL / ImgH < 0.5

[0594] Equation 61 can set the optical axis distance between the image sensor 300 and the last lens and the diagonal length from the optical axis of the image sensor 300. When the optical system 1000 according to the second embodiment satisfies Equation 61, the optical system 1000 can ensure a relatively large image sensor 300. For example, the BFL for an application of a large image sensor 300 of about 1-inch size, and can minimize the distance between the last lens and the image sensor 300, so that good optical performance can be obtained at the center and periphery of the FOV. Preferably, Equation 61 can satisfy: 0.10 < BFL / ImgH < 0.40.

[0595] [Equation 62] 4 < TTL / BFL < 10

[0596] Equation 62 can set the total optical axis length TTL of the optical system and the optical axis distance BFL (unit, mm) between the image sensor 300 and the last lens. When the optical system 1000 according to the second embodiment satisfies Equation 62, the optical system 1000 ensures BFL and can be provided in a thin and compact manner. Equation 62 can satisfy: 6 < TTL / BFL < 9.

[0597] [Equation 63] 0.5 < F / TTL < 1.5

[0598] Equation 63 can set the total focal length F and the total optical axis length TTL of the optical system 1000. Therefore, a thin and compact optical system can be provided. Preferably, Equation 63 can satisfy: 0.5 < F / TTL < 1.

[0599] [Equation 63-1] 0 < F# / TTL < 0.5

[0600] Equation 63-1 can set the F-number F# and the total optical axis length TTL of the optical system 1000. Therefore, a thin and compact optical system can be provided.

[0601] [Equation 64] 3 < F / BFL < 10

[0602] Equation 64 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. When the optical system 1000 according to the second embodiment satisfies Equation 64, the optical system 1000 can have a set FOV and an appropriate focal length, and a thin and compact optical system can be provided. In addition, the optical system 1000 can minimize the distance between the last lens and the image sensor 300, so it has good optical characteristics at the peripheral part of the FOV. Preferably, Equation 64 can satisfy: 4 < F / BFL < 8.

[0603] [Equation 65] 0 < F / ImgH < 3

[0604] Equation 65 can set the total focal length F (unit: mm) of the optical system 1000 and the diagonal length (ImgH) from the optical axis of the image sensor 300. The optical system 1000 uses a relatively large image sensor 300 (for example, a size of about 1 inch) and can have improved aberration characteristics. Preferably, Equation 65 can satisfy: 0.7 < F / ImgH < 1.5.

[0605] [Equation 66] 1 < F / EPD < 5

[0606] Equation 66 can set the total focal length F and the EPD of the optical system 1000. Therefore, the overall brightness of the optical system can be controlled. Preferably, Equation 66 can satisfy: 1.5 < F / EPD < 3.

[0607] [Equation 67] 0 < BFL / TD < 0.5

[0608] In Equation 67, the optical axis distance BFL between the image sensor 300 and the last lens and the optical axis distance TD of the lens are set. When this condition is satisfied, the optical system 1000 can provide a thin and compact optical system. Preferably, Equation 67 can satisfy: 0 < BFL / TD < 0.3. When BFL / TD exceeds 0.3, BFL is designed to be larger than TD, so the size of the entire optical system becomes larger, making it difficult to manufacture the optical system, and the distance between the ninth lens and the image sensor becomes longer, so the unnecessary light amount passing through the eighth lens and the image sensor may increase, resulting in a decrease in resolution, for example, deterioration of aberration characteristics.

[0609] [Formula 68] <EPD / ImgH / FOV<0.2

[0610] In Formula 68, a relationship between the entrance pupil diameter EPD, the length of half the maximum diagonal length of the image sensor (ImgH), and the FOV can be established. Therefore, the overall size and brightness of the optical system can be controlled. Preferably, Formula 68 can satisfy: <EPD / ImgH / FOV<0.01。

[0611] [Formula 69] 10 <FOV / F#<55

[0612] Formula 69 can establish the relationship between the FOV and F number of the optical system. Preferably, Formula 69 can satisfy: 30 <FOV / F#<50。

[0613] [Formula 70] <n1 / n2<1.5

[0614] When the refractive indices n1 and n2 at the d-line of the first lens 111 and the second lens 112 of Formula 70 satisfy the above range, the optical system can improve the resolution of the incident light. Preferably, the condition: 0.5 <n1 / n2<1。

[0615] [Equation 71] <n3 / n4<1.5

[0616] If the refractive indices n3 and n4 at the d-line of the third lens 113 and the fourth lens 114 of Formula 71 satisfy the above range, the optical system can improve the resolution of the incident light of the second lens group LG2. Preferably, Formula 71 can satisfy: 0.5 <n3 / n4<1。

[0617] [Equation 72](v2*n2)<(v1*n1)

[0618] In Equation 72, when the refractive index n1 and the Abbe number v1 of the first lens 111 and the refractive index n2 and the Abbe number v2 of the second lens 112 are satisfied, the first lens 111 and the second lens 112 may control the dispersion of the transmitted light.

[0619] [Formula 73] <Inf91 / Inf92<1

[0620] In equation 73, the distance Inf91 from the optical axis OA to the critical point of the seventeenth surface S17 of the ninth lens 119 and the distance Inf92 from the optical axis OA to the critical point of the eighteenth surface S18 can be set. When the above conditions are met, the curvature aberration of the ninth lens can be controlled. Equation 73 can satisfy: 0.2 <Inf91 / Inf92<0.8。

[0621] [Formula 74]0 <Inf81 / Inf82<1.5

[0622] In equation 74, the distance Inf81 from the optical axis OA to the critical point of the fifteenth surface S15 of the eighth lens 118 and the distance Inf82 from the optical axis OA to the critical point of the sixteenth surface S16 can be set. When the above conditions are met, the curvature aberration of the eighth lens can be controlled. Equation 74 can satisfy: 0.5 <Inf81 / Inf82<1。

[0623] [Equation 75] 0.8 <Inf82 / Inf92<1.5

[0624] If equation 75 is satisfied, the curvature aberration of the eighth lens and the ninth lens can be controlled. Equation 75 can satisfy: 1 <Inf82 / Inf92<1.5。

[0625] [Equation 76] 1<(TTL / ImgH)*|Max_Sag92|*n<15

[0626] Equation 76 can set the edge height of the sensor side surface of the final lens, TTL and ImgH, preferably, satisfying the following condition: 10<(TTL / ImgH)*|Max_Sag92|*n<15.

[0627] [Equation 77] 1<(F / ImgH)*|Max_Sag92|*n<15

[0628] Formula 77 can set the edge height of the sensor-side surface of the final lens, F and ImgH, preferably satisfying the following condition: 8<(F / ImgH)*|Max_Sag92|*n<15.

[0629] [Formula 78]30<(TD_LG2 / TD_LG1)*n<60

[0630] [Formula 79]15<(CT_Max+CG_Max)*n<45

[0631] [Equation 80] 100 < (FOV * TTL) / n < 200

[0632] Preferably, according to the FOV of the optical system and the number n of lenses, Formula 80 may satisfy the condition: 130<(FOV*TTL) / n<180.

[0633] [Equation 81] FOV < (TTL*n)

[0634] [Equation 82] 10<(CA_Max*TD) / n<50

[0635] [Equation 83] 300<|Max_Sag|*TD*n

[0636] In Formula 83, Max_Sag is the maximum concave value (absolute value) in the object-side surface and the sensor-side surface of each lens, and preferably satisfies the following condition: 300<|Max_Sag|*TD*n<500. In the above formula, * indicates multiplication.

[0637] In equations 76 to 83, n is the total number of lenses, and the optical axis distance TD_LG1 of the first lens group LG1, the optical axis distance TD_LG2 of the second lens group LG2, the maximum center thickness CT_Max of the lens, the maximum center distance CG_Max, FOV, TTL, the maximum concave value on the sensor side surface of the eighth lens 118 or the maximum concave value Max_Sag among all lenses, the optical axis distance TD of the lens, etc. can be set according to the total number of lenses. Therefore, the chromatic aberration, resolution, size, etc. of the optical system having 10 or less lenses can be controlled.

[0638] like Fig.13 As shown, in the second embodiment, at least one or all lens surfaces of the plurality of lenses may include an aspheric surface having a 30th order aspheric coefficient. For example, the first lens 111 to the ninth lens 119 may include lens surfaces having a 30th order aspheric coefficient from the first surface S1 to the eighteenth surface S18. As described above, an aspheric surface having a 30th order aspheric coefficient (a value other than "0") can significantly change the aspheric shape of the peripheral portion, so the optical performance of the peripheral portion of the FOV can be well corrected.

[0639] The optical system 1000 according to the second embodiment may satisfy at least one or two of equations 1 to 83. In this case, the optical system 1000 has improved optical characteristics and improved resolution, and may improve aberration and distortion characteristics. In addition, the optical system 1000 may ensure the BFL applied to a large image sensor 300, and may minimize the distance between the last lens and the image sensor 300, thereby having good optical performance in the center and peripheral portions of the FOV. In addition, when the optical system 1000 satisfies at least one of equations 1 to 83, it may include a relatively large image sensor 300, have a relatively small TTL value, and be thinner. A compact optical system and a camera module having the optical system may be provided.

[0640] Fig.12 It is shown that according to Fig.10 Examples of lens data for embodiments of optical systems. Fig.12 As shown, the radius of curvature on the optical axis OA of the first lens 111 to the ninth lens 119, the center thickness CT of each lens, the center distance CG between two adjacent lenses, the refractive index at the d line (588nm), the Abbe number and the effective radius (semi-aperture) and the focal length.

[0641] like Fig.14 As shown, the first thickness T1 to the ninth thickness T9 of the first lens 111 to the ninth lens 119 can be expressed as a distance of more than 0.1 mm in the direction Y from the center to the edge of each lens. In addition, based on the first distance G1 between the first lens and the second lens, the second distance G2 between the second lens and the third lens, the third distance G3 between the third lens and the fourth lens, the fourth distance G4 between the fourth lens and the fifth lens, the fifth distance G5 between the fifth lens and the sixth lens, the sixth distance G6 between the sixth lens and the seventh lens, and the seventh distance G7 between the seventh lens and the eighth lens, the distance between adjacent lenses can be expressed as a distance of more than 0.1 mm in the direction from the center toward the edge. By using the above-mentioned first thickness T1 to the ninth thickness T9 and the first distance G1 to the eighth distance G8 to correct distortion aberration, an optical system can be provided in a thin and compact size.

[0642] Fig.15 shows the height (concave value) from a straight line in the Y-axis direction orthogonal to the center of the object-side surface L8S1 and the sensor-side surface L8S2 of the eighth lens 118 and the object-side surface L9S1 and the sensor-side surface L9S2 of the ninth lens 119 according to the embodiment of the present invention to the lens surface at a distance of 0.1 mm or more, and Fig.19 It is shown Fig.15 A graph showing data of the concave values ​​of the eighth lens and the ninth lens.

[0643] Reference Fig.11 , Fig.15 and Fig.19 , the object side surface L8S1 and the sensor side surface L8S2 of the eighth lens have critical points protruding toward the sensor side based on the centers of the respective lens surfaces, and it can be seen that the critical point P1 of L8S1 exists at 3.7 mm ± 0.3 mm from the optical axis, and the critical point P2 of L8S2 exists at 4.3 mm ± 0.3 mm from the optical axis. The object side surface L9S1 and the sensor side surface L9S2 of the ninth lens have critical points protruding toward the sensor side based on the centers of the respective lens surfaces, and it can be seen that the critical point P3 of L9S1 exists at 1.2 mm ± 0.3 mm from the optical axis, and the critical point P4 of L9S2 exists at 3.3 mm ± 0.3 mm from the optical axis.

[0644] Fig.16 : is a table showing the inclination angle between the object-side surface and the sensor-side surface of the eighth lens and the ninth lens according to the embodiment of the present invention with respect to the height (sag value) from the straight line in the Y-axis direction to the lens surface at a distance of 0.1 mm or more. Fig.16As shown, it can be seen that the maximum inclination angle (absolute value) of the object-side surface L8S1 and the sensor-side surface L8S2 of the eighth lens 118 is greater than the maximum inclination angle (absolute value) of the object-side surface L9S1 and the sensor-side surface L9S2 of the ninth lens 119. In addition, the position of the maximum inclination angle (absolute value) of the object-side surface L8S1 and the sensor-side surface L8S2 of the eighth lens 118 is adjacent to or located at the edge, and can be set to be more outward than the position of the maximum inclination angle (absolute value) of the object-side surface L9S1 and the sensor-side surface L9S2 of the ninth lens 119. Therefore, the effective diameter of the ninth lens 119 can be increased, and the ninth lens 119 can guide the light traveling through the outside of the eighth lens 118 to the image sensor 300.

[0645] Fig.17 is a graph showing the diffraction MTF characteristics of the optical system according to the embodiment of the present invention, and Fig.18 : is a graph showing aberration characteristics of an optical system according to an embodiment of the present invention.

[0646] like Fig.17 As shown, in the aberration curve diagram of the optical system according to the embodiment, the figure is a curve diagram measuring longitudinal aberration, astigmatism field aberration and distortion from left to right, and is a curve diagram measured from 0.000mm to 12.722mm in units of 1.272mm. The X-axis can represent focal length (mm) and distortion (%), and the Y-axis can represent the height of the image. In addition, the curve diagram for spherical aberration is a curve diagram for light in wavelength bands of about 470nm, about 510nm, about 555nm, about 610nm and about 660nm, and the curve diagram for astigmatism and distortion aberration is a curve diagram for light in a wavelength band of about 555nm. In Fig.18 In the aberration diagram, it can be interpreted that the closer the curves are to the Y axis, the better the aberration correction function. Fig.18 , it can be seen that the measured values ​​of the optical system 1000 according to the embodiment are adjacent to the Y axis in most areas. That is, the optical system 1000 according to the embodiment can have improved resolution and can have good optical performance not only in the center of the FOV but also in the peripheral part. As confirmed in the second embodiment, the lens system according to the second embodiment of the present invention is compact and lightweight, has a lens configuration of less than 10 elements (for example, 9 elements), and has good spherical aberration, astigmatism, distortion aberration, chromatic aberration and coma at the same time. Since it is calibrated and can be implemented with high resolution, it can be used as a built-in camera optical device.

[0647] Table 4 shows the items of the above-mentioned various formulas in the optical system 1000 according to the embodiment, and shows the TTL, BFL, F value, ImgH, focal lengths F1, F2, F3, F4, F5, F6, F7, F8 and F9 of each lens, edge thickness, edge distance, synthetic focal length, etc. of the optical system 1000.

[0648] [Table 4]

[0649]

[0650]

[0651] Table 5 shows Fig.10 The result values ​​of the above equations 1 to 42 in the optical system 1000. Referring to Table 5, it can be seen that the optical system 1000 satisfies at least one, two or three of equations 1 to 42. Therefore, the optical system 1000 can improve the optical performance and optical characteristics of the central part and the peripheral part of the FOV.

[0652] [Table 5]

[0653]

[0654]

[0655] Table 6 shows Fig.10 The result values ​​of the above equations 43 to 83 in the optical system 1000. Referring to Table 6, the optical system 1000 can satisfy at least one or two of equations 1 to 42. Specifically, it can be seen that the optical system 1000 according to the second embodiment satisfies all of the above equations 1 to 83. Therefore, the optical system 1000 can improve the optical performance and optical characteristics of the central part and the peripheral part of the FOV.

[0656] [Table 6]

[0657]

[0658]

[0659] Fig. 20 is a diagram showing a camera module applied to a mobile terminal according to an embodiment. Fig. 20 , the mobile terminal 1 may include a camera module 10 disposed on the rear side. The camera module 10 may include an image capturing function. In addition, the camera module 10 may include at least one of an auto focus function, a zoom function, and an OIS function.

[0660] The camera module 10 can process image frames of static images or videos obtained by the image sensor 300 in a camera mode or a video call mode. The processed image frames can be displayed on a display unit (not shown) of the mobile terminal 1 and can be stored in a memory (not shown). In addition, although not shown in the figure, the camera module can also be set on the front side of the mobile terminal 1. 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 can have a thin structure and have improved distortion and aberration characteristics. In addition, the camera module 10 can have good optical performance even in the central and peripheral parts of the FOV.

[0661] In addition, the mobile terminal 1 may further include an automatic focusing device 31. The automatic focusing device 31 may include an automatic focusing function using a laser. The automatic focusing device 31 may be mainly used in a case where the automatic focusing function of the image using the camera module 10 disclosed above deteriorates, for example, at a close distance within 10 m or in a dark environment. The automatic focusing device 31 may include a light emitting unit including a vertical cavity surface emitting laser (VCSEL) semiconductor device and a light receiving unit such as a photodiode that converts light energy into electrical energy. In addition, the mobile terminal 1 may further include a flash module 33. The flash module 33 may include a light emitting device that emits light inside. The flash module 33 may be operated by operating the camera of the mobile terminal or by control by a user.

[0662] The features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to one embodiment. In addition, the features, structures, effects, etc. shown in the various embodiments can be combined or modified and implemented in other embodiments by a person of ordinary skill in the field to which the embodiments belong. Therefore, the content related to such combination and modification should be interpreted as being included in the scope of the present invention. In addition, although the above description focuses on examples, this is only an example, and does not limit the present invention, and those skilled in the art will understand the above examples without departing from the basic characteristics of the present embodiment. You will be able to see that various modifications and applications can be made. For example, the various components specifically shown in the examples can be modified and implemented. And these changes and differences in the application should be interpreted as being included in the scope of the present invention as defined in the appended claims.

Claims

1. An optical system, comprising: A first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens, which are arranged along the optical axis from the object side towards the sensor side, wherein the first lens has a positive refractive power on the optical axis and has a shape with a convex object-side surface, wherein, among the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens, the number of meniscus lenses that are convex towards the object side on the optical axis is more than 5, wherein each of the object-side surface and the sensor-side surface of the seventh lens has a critical point, wherein each of the object-side surface and the sensor-side surface of the eighth lens has a critical point, wherein the critical point of the object-side surface of the eighth lens is set closer to the optical axis than the critical points of the object-side surface and the sensor-side surface of the seventh lens, and wherein the following formula is satisfied: 1.5 < ImgH / ∑CT < 2.2 1.6 < ImgH / ∑CG < 2.3 wherein ImgH is 1 / 2 of the maximum diagonal length of the image sensor, ∑CT is the sum of the central thicknesses of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens, and ∑CG is the sum of the central distances of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens.

2. The optical system according to claim 1, wherein: The critical point of the object-side surface of the eighth lens is set closer to the optical axis than the critical point of the sensor-side surface of the eighth lens.

3. The optical system according to claim 2, wherein: Each of the object-side surface and the sensor-side surface of the fourth lens has a critical point.

4. The optical system according to claim 3, wherein: Each of the object-side surface and the sensor-side surface of the fifth lens has a critical point.

5. The optical system according to any one of claims 1 to 4, wherein: The following formula is satisfied: (TTL * n) > FOV wherein TTL is the optical axis distance from the center of the object-side surface of the first lens to the image surface of the image sensor, n is the total number of lenses, and FOV is the field of view.

6. The optical system according to any one of claims 1 to 4, in, satisfying the following formula: ImgH < TTL 150 < TTL * ImgH wherein ImgH is 1 / 2 of the maximum diagonal length of the image sensor, and TTL is the optical axis distance from the center of the object-side surface of the first lens to the image surface of the image sensor.

7. The optical system according to any one of claims 1 to 4, wherein: The refractive index of the first lens satisfies: 1.50 < n1 < 1.6, wherein the refractive index of the second lens satisfies: 1.60 < n2, and wherein n2 is the maximum refractive index among the refractive indices of the lenses.

8. The optical system according to claim 1, wherein: The first lens, the second lens, the fourth lens, the fifth lens, and the seventh lens have a meniscus shape that is convex toward the object side on the optical axis, Wherein, the eighth lens is a meniscus lens convex toward the object side on the optical axis.

9. The optical system according to any one of claims 1 to 5, wherein: The maximum effective diameters CA_Max of the object-side surface and the sensor-side surface of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy the following formula: 0.1 <CA_Max / (2*ImgH)<1 0.5 <TTL / CA_Max<2 Wherein, ImgH is 1 / 2 of the maximum diagonal length of the image sensor, and TTL is the optical axis distance from the object-side surface of the first lens to the image surface of the image sensor.

10. The optical system according to any one of claims 1 to 4, in, Satisfy the following formula: (v2*n2)<(v1*n1) v1 is the Abbe number of the first lens, v2 is the Abbe number of the second lens, n1 is the refractive index of the first lens, and n2 is the refractive index of the second lens.

11. An optical system comprising: a first lens having a meniscus shape convex toward the object; a second lens disposed on a sensor side of the first lens; an nth lens, the nth lens being closest to the image sensor; an n-1th lens, the n-1th lens being disposed on the object side of the nth lens; Three or more lenses are arranged between the second lens and the n-1th lens, wherein the second lens has the smallest effective diameter among the lenses of the optical system, wherein the nth lens has the largest effective diameter among the lenses of the optical system, wherein the first lens to the nth lens are aligned with the optical axis, wherein n is less than 10, Among them, the number of lenses having positive refractive power among the n lenses is greater than the number of lenses having negative refractive power, wherein the sensor-side surface of the nth lens has the smallest curvature radius among the object-side surface and the sensor-side surface of the lens, Wherein, the lens surface having the largest effective diameter in the lens is CA_max, Wherein, 1 / 2 of the diagonal length of the image sensor is ImgH, Among them, the following formula is satisfied: 0.5≤CA_max / (2*ImgH)<1.

12. The optical system according to claim 11, in, The total effective focal length is F, The curvature radius of the object-side surface of the first lens is L1R1. Wherein, the curvature radius of the sensor side surface of the nth lens is LnR2, Among them, the following formula is satisfied: 1<F / L1R1<5, Among them, the following formula is satisfied: 2<F / LnR2<4.

5.

13. The optical system according to claim 11, in, The sum of the center thickness of the lens is ∑CT, Among them, the sum of the optical axis distances between two adjacent lenses is ∑CG, Wherein, the maximum center thickness of the lens is CT_Max, Wherein, the maximum optical axis distance between adjacent lenses is CG_Max, Among them, the following formula is satisfied: 0.5<∑CT / ∑CG<1.2, Among them, the following formula is satisfied: 15<(CT_Max+CG_Max)*n<45.

14. An optical system according to any one of claims 11 to 13, in, The object side surface and the sensor side surface of the nth lens have a critical point, The object side surface and the sensor side surface of the n-1th lens have a critical point. The critical point of the sensor-side surface of the nth lens is arranged to be closer to the optical axis than the critical point of the object-side surface of the (n-1)th lens and the critical point of the sensor-side surface.

15. A camera module, comprising: An image sensor disposed on a sensor side of the plurality of lenses; as well as a filter disposed between the image sensor and a final lens, Wherein, the optical system comprises the optical system described in any one of claims 1 and 11.

Images