Optical system and image pickup device module including the same

Abstract

An optical system disclosed in an embodiment of the present invention includes first to ninth lenses arranged in a direction from an object side to a sensor side along an optical axis, wherein: the first lens has a positive (+) refractive power on the optical axis and has a meniscus shape protruding toward the object side; a second lens having a positive refractive power on an optical axis and both surfaces thereof having a convex shape; a ninth lens having a negative (-) refractive power on the optical axis and having a meniscus shape protruding toward the object side; a lens having the largest absolute value of focal length among the first to ninth lenses is the fourth lens; a lens surface having a maximum absolute value of a radius of curvature among the first to ninth lenses is an object-side surface of the sixth lens; the focal length of the first lens is F1; the focal length of the ninth lens is F9; the mathematical expression of-0.5 lt is met; f9 / F1lt; 0.

Description

Technical Field

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

[0002] The camera module captures an object and stores the object as an image or video, and 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, tablet PCs, and laptop computers, but also to drones and vehicles to provide various functions.

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

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

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

[0006] In addition, in order to achieve high resolution and high definition, the size of the image sensor is also increasing. However, when the size of the image sensor increases, the TTL (total track length) of the optical system including multiple lenses also increases, thereby increasing the thickness of the camera device including the optical system and the mobile terminal.

[0007] Therefore, a new optical system that can solve the above problems is needed. Summary of the invention

[0008] Technical issues

[0009] Embodiments of the present invention provide an optical system with improved optical properties.

[0010] Embodiments provide an optical system having excellent optical performance at both the central portion and the peripheral portion of the field of view.

[0011] Embodiments provide an optical system that can have a thin structure.

[0012] Technical solution

[0013] The optical system according to an embodiment of the present invention includes a first lens to a ninth lens arranged along the optical axis from the object side toward the sensor side. Among them, the first lens has a positive refractive power on the optical axis and has a meniscus shape convex toward the object side, the second lens has a positive refractive power on the optical axis and has a shape convex on both sides, and the ninth lens has a negative refractive power on the optical axis and has a meniscus shape convex toward the object side. The lens having the largest absolute value of the focal length among the first lens to the ninth lens is the fourth lens, and the lens surface having the largest absolute value of the radius of curvature among the first lens to the ninth lens is the object side surface of the sixth lens. The focal length of the first lens is F1, the focal length of the ninth lens is F9, and the following formula can be satisfied: -0.5 < F9 / F1 < 0.

[0014] According to an embodiment of the present invention, the optical axis distance from the center of the object side surface of the first lens to the upper surface of the image sensor is TTL, and half of the diagonal length of the image sensor is ImgH, and the following formula can be satisfied: 0.5 < TTL / (2*ImgH) < 0.9.

[0015] According to an embodiment of the present invention, the refractive index of the first lens is n1, the Abbe number is v1, the refractive index of the third lens is n3, and the Abbe number is v3, and the following formula can be satisfied: (v3*n3) < (v1*n1). In addition, the following formula can be satisfied: n1 < 1.6, and n1 < n3 and v1 > v3.

[0016] According to an embodiment of the present invention, the refractive index of the second lens is n2, the Abbe number is v2, and the following formula can be satisfied: v3*n3 < v2*n2.

[0017] According to an embodiment of the present invention, the total focal length of the optical system is F, the brightness of the optical system is F#, and the following formula can be satisfied: 2 < F / F# < 4, where F# < 2.3.

[0018] According to an embodiment of the present invention, the sixth lens can have a positive refractive power.

[0019] According to an embodiment of the present invention, a lens having the smallest effective diameter among the first to ninth lenses may be the second lens, and a lens having the largest effective diameter among the first to ninth lenses may be the ninth lens.

[0020] According to an embodiment of the present invention, a center distance between the third lens and the fourth lens may be greater than a center distance between the second lens and the third lens, and greater than a center distance between the fourth lens and the fifth lens.

[0021] According to an embodiment of the present invention, an object-side surface of the fourth lens may have a curvature radius of 500 mm or more on the optical axis.

[0022] According to an embodiment of the present invention, an optical system includes: a first lens having a meniscus shape convex toward an object; a second lens arranged on the sensor side of the first lens; a third lens arranged on the sensor side of the second lens; a fourth lens arranged on the sensor side of the third lens; an nth lens closest to the image sensor; an n-1th lens arranged on the object side of the nth lens; two or more lenses arranged between the fourth lens and the n-1th lens, wherein the second lens has the smallest effective diameter among the lenses, the nth lens has the largest effective diameter among the lenses of the optical system, the first lens to the nth lens are aligned along the optical axis, the center distance between the third lens and the fourth lens is the largest among the center distances between the first lens to the fourth lens, and the curvature radius of the object side surface of the fourth lens is L4R1, the curvature radius of the sensor side surface of the fourth lens is L4R2, and the following formula can be satisfied: 100<|L4R2|<|L4R1|.

[0023] According to an embodiment of the present invention, the sum of the center thicknesses of the first lens to the nth lens is ΣCT, the sum of the center distances between the first lens to the nth lens is ΣCG, and the following formula may be satisfied: ΣCG<ΣCT.

[0024] According to an embodiment of the present invention, the total number of lenses is n, and may satisfy the following formula: 5<(CT_Max+CG_Max)*n<20.

[0025] According to an embodiment of the present invention, the number of lenses having a refractive index less than 1.6 at the d-line among the lenses may be five or more, and the number of lenses having an Abbe number greater than 45 among the lenses may be five or more.

[0026] According to an embodiment of the present invention, the sum of the refractive indices of the lenses at the d-line is ΣIndex, the sum of the Abbe numbers of the lenses is ΣAbbe, and the following formula may be satisfied: 10<ΣAbbe / ΣIndex<50.

[0027] According to an embodiment of the present invention, the optical axis distance from the center of the object side surface of the first lens to the upper surface of the image sensor is TTL, half of the diagonal length of the image sensor is ImgH, and the following formula can be satisfied: 1 < TTL / ImgH < 2.

[0028] According to an embodiment of the present invention, the object side surface and the sensor side surface of the nth lens have critical points, the object side surface and the sensor side surface of the (n - 1)th lens have critical points, and the sensor side surface of the nth lens has a critical point. The critical point of the sensor side surface of the nth lens can be set closer to the edge than the critical points of the object side surface and the sensor side surface of the (n - 1)th lens.

[0029] The optical system according to an embodiment of the present invention includes: a first lens group having a first lens to a third lens on the object side; a second lens group disposed on the sensor side of the first lens group and having five or more lenses compared to the number of lenses in the first lens group; and an aperture stop disposed around the object side surface or the sensor side surface of the second lens, wherein the first lens group has a positive refractive power, the second lens group has a negative refractive power, and the second lens has a convex object side surface and a convex sensor side surface on the optical axis, the optical axis distance from the object side center of the first lens group to the image sensor is TTL, the field of view of the optical system is FOV, and half of the diagonal length of the image sensor is ImgH, n is the total number of lenses, and the following formula can be satisfied: (TTL * n) < FOV, and 0.5 < TTL / (2 * ImgH) < 0.9.

[0030] The imaging device module according to an embodiment of the present invention includes: an image sensor disposed on the sensor side of a plurality of lenses; and a filter disposed between the image sensor and the last lens, wherein the optical system includes the optical system according to any one of claims 1, 11, or 18, F is the total focal length, TTL is the distance from the center of the optical axis of the object side of the lens closest to the object side to the upper surface of the image sensor, ImgH is half of the maximum diagonal length of the image sensor, the following formula can be satisfied: 0.5 < F / TTL < 1.5, and 1 < TTL / ImgH < 2.

[0031] Advantageous Effects

[0032] The optical system and the imaging device module according to the embodiment can have improved optical properties. Specifically, the optical system can have improved aberration characteristics and resolution according to the surface shape, refractive power, thickness of the plurality of lenses, and the distance between adjacent lenses of the plurality of lenses.

[0033] The optical system and the camera module according to the embodiments may have improved distortion and aberration characteristics and may have good optical performance at the central portion and the peripheral portion of a field of view (FOV).

[0034] The optical system according to the embodiment may have improved optical characteristics and a small total track length (TTL), so that the optical system and a camera module including the same may be provided in a slim and compact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 1 is a configuration diagram of an optical system and an imaging device module according to a first embodiment of the present invention.

[0036] Figure 2 1 is an explanatory diagram showing a relationship between an image sensor and nth to n-1th lenses in an optical system according to an embodiment of the present invention.

[0037] Figure 3 It is shown that according to Figure 1 A table of lens data for an embodiment of an optical system.

[0038] Figure 4 is based on Figure 1 Examples of aspheric coefficients of lenses of embodiments of the optical system.

[0039] Figure 5 2 is a configuration diagram of an optical system and an imaging device module according to a second embodiment of the present invention.

[0040] Figure 6 It is shown that according to Figure 5 A table of lens data for an embodiment of an optical system.

[0041] Figure 7 yes Figure 5 Examples of aspheric coefficients of lenses of an optical system.

[0042] Figure 8 2 is a configuration diagram of an optical system and an imaging device module according to a third embodiment of the present invention.

[0043] Fig. 9 It is shown that according to Figure 8 A table of lens data for an embodiment of an optical system.

[0044] Fig.10 yes Figure 8 Examples of aspheric coefficients of lenses of an optical system.

[0045] Fig.11 is a diagram showing that a camera module according to an embodiment is applied to a mobile terminal. DETAILED DESCRIPTION

[0046] 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 various other forms, and within the scope of the technical spirit of the present invention, one or more of the components can be selectively combined and replaced for use. In addition, unless specifically defined and clearly described, the terms (including technical terms and scientific terms) used in the embodiments of the present invention can be interpreted according to the meanings that can be generally understood by ordinary technicians in the field to which the present invention belongs, and commonly used terms (for example, terms defined in dictionaries) should be able to interpret their meanings in consideration of the contextual meanings of the relevant technology.

[0047] In addition, the terms used in the embodiments of the present invention are used to illustrate the embodiments, and are not intended to limit the present invention. In this specification, unless otherwise specifically stated in a phrase, the singular form may also include the plural form, and in the case of describing at least one (or one or more) of A and (with) B, C, it may include one or more of all combinations that can be combined with A, B and C. In the components describing the embodiments of the present invention, 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 may not be determined by the properties, sequence or process of the corresponding constituent elements by the terms. And when describing a component "connected", "coupled" or "engaged" to another component, the description may include not only direct connection, coupling or engagement to another component, but also "connected", "coupled" or "engaged" by another component between the component and another component. In addition, in the case of being described as being formed or arranged on "above (up)" or "below (below)" of each component, the description includes not only the situation that the two components are in direct contact with each other, but also the situation that one or more other components are formed or arranged between the two components. In addition, when the expression "above" or "below" is used, it can refer to a downward direction as well as an upward direction with respect to one element.

[0048] In the description of the present invention, "object side surface" may refer to the surface of the lens facing the object side surface relative to the optical axis (OA), and "sensor side surface" may refer to the surface of the lens facing the imaging surface (image sensor) relative to the optical axis. The convex surface of the lens may mean that the lens surface on the optical axis has a convex shape, and the concave surface of the lens may mean that the lens surface on the optical axis has a concave shape. The radius of curvature, the center thickness, and the distance between the lenses described in the table of lens data may mean the value on the optical axis, and the unit is mm. The vertical direction may mean the direction perpendicular to the optical axis, and the end of the lens or the lens surface may mean the end or edge of the effective area of ​​the lens through which the incident light passes. Depending on the measurement method, the effective diameter on the lens surface may have a measurement error of up to ±0.4mm. The paraxial area refers to a very narrow area near the optical axis, and is an area where the distance of the light falling from the optical axis (OA) is almost zero. In the following, the concave shape or convex shape of the lens surface will be described as the optical axis, and the paraxial area may also be included.

[0049] Figure 1 is a configuration diagram of an optical system and an imaging device module according to a first embodiment of the present invention, Figure 2 is an explanatory diagram showing a relationship between nth to n-1th lenses and an image sensor in an optical system according to an embodiment of the present invention, Figure 3 It is shown that according to Figure 1 A table of lens data of an embodiment of an optical system, Figure 4 is based on Figure 1 Examples of aspheric coefficients of lenses of embodiments of the optical system, Figure 5 is a configuration diagram of an optical system and an imaging device module according to a second embodiment of the present invention, Figure 6 It is shown that according to Figure 5 A table of lens data of an embodiment of an optical system, Figure 7 yes Figure 5 Examples of aspheric coefficients of lenses of an optical system, Figure 8 is a configuration diagram of an optical system and an imaging device module according to a third embodiment of the present invention, Fig. 9 It is shown that according to Figure 8 A table of lens data of an embodiment of an optical system, Fig.10 yes Figure 8 Examples of aspheric coefficients of lenses of an optical system.

[0050] Reference Figures 1 to 10, the optical system (1000) or the camera module may include a plurality of lens groups (LG1, LG2). For example, the optical system (1000) may include a first lens group (LG1) and a second lens group (LG2) arranged in sequence along an optical axis (OA) from an object side toward an image sensor (300). The second lens group (LG2) may be disposed between the first lens group (LG1) and the image sensor (300). Each of the plurality of lens groups (LG1, LG2) includes at least two lenses. 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, 1.5 times or more of the number of lenses of the first lens group (LG1), for example, in the range of 1.5 times to 2.5 times.

[0051] The first lens group (LG1) may include two or more lenses. The first lens group (LG1) may include, for example, three lenses. The second lens group (LG2) may include five or more lenses and seven or less lenses. The number of lenses of the second lens group (LG2) may be five or more compared to the number of lenses of the first lens group (LG1). The second lens group (LG2) may include, for example, six lenses. The optical system (1000) may include eleven or less lenses or ten or less lenses.

[0052] In the optical system (1000), the total track length TTL can be less than 80% of the diagonal length of the image sensor (300), for example, in the range of 60% to 80% or 70% to 80%. TTL is the distance from the object side surface of the first lens (101) closest to the object to the upper surface of the image sensor (300) on the optical axis (OA). The diagonal length of the image sensor (300) is twice ImgH, and ImgH is half of the diagonal length of the image sensor (300). Therefore, a slim optical system and a camera module having the slim optical system can be provided. The total number of lenses in the first lens group and the second lens group (LG1, LG2) is 8 to 10.

[0053] The first lens group (LG1) may have a positive (+) refractive power. The second lens group (LG2) may have a negative refractive power different from the refractive power of the first lens group (LG1). The first lens group (LG1) and the second lens group (LG2) have different focal lengths, so that they can have good optical performance in the center and peripheral portions of the field of view (FOV). The refractive power is the reciprocal of the focal length.

[0054] The first lens group (LG1) may include a stack of lenses having a meniscus shape convex toward the object. At least one or two of the lenses of the first lens group (LG1) may be arranged on the object side surface and the sensor side surface without a critical point from the optical axis to the end of the effective area. Therefore, since the lenses of the first lens group (LG1) are provided with the least critical points, the effective diameter of the lenses of the second lens group (LG2) adjacent to the first lens group (LG1) may not be increased.

[0055] 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 can be equal to or less than the number of lenses having no critical point on at least one of the object side surface and the sensor side surface. Therefore, the TTL can be reduced by the lens surface of the second lens group (LG2) and the size of the image sensor (300) can be increased.

[0056] The first lens group (LG1) can refract light incident through the object side surface to collect the light, and the second lens group (LG2) can refract light emitted through the first lens group (LG1) to the peripheral portion of the image sensor (300). In addition, the two lens surfaces facing each other of the first lens group and the second lens group (LG1, LG2) can have, for example, a concave sensor side surface of the first lens group (LG1) and a concave object side surface of the second lens group (LG2). In addition, the two lenses facing each other in the first lens group and the second lens group (LG1, LG2) can have opposite refractive powers.

[0057] Two lenses adjacent to the region between the first lens group and the second lens group (LG1, LG2) may satisfy the following conditions.

[0058] Condition 1: The refractive index of the lens with positive refractive power < the refractive index of the lens with negative refractive power

[0059] Condition 2: Dispersion value of lens with positive refractive power > dispersion value of lens with negative refractive power

[0060] Therefore, chromatic aberrations generated between lenses can be corrected mutually.

[0061] The absolute difference between the focal length of the second lens group (LG2) and the focal length of the first lens group (LG1) may be 5 or more, for example, 10 or more. Therefore, the optical system (1000) according to the embodiment may have improved aberration control characteristics such as chromatic aberration and distortion aberration by controlling the refractive power and focal length of each lens group (LG1, LG2), and may have good optical performance at the central portion and the peripheral portion of the FOV.

[0062] In the optical axis (OA), the first lens group (LG1) and the second lens group (LG2) may have a set distance. The optical axis distance between the first lens group (LG1) and the second lens group (LG2) is a separation distance in the optical axis (OA), and may be an optical axis distance between a sensor-side surface of a lens closest to the sensor side among the lenses in the first lens group (LG1) and an object-side surface of a lens closest to the object side among the lenses in the second lens group (LG2). The optical axis distance between the first lens group (LG1) and the second lens group (LG2) may be greater than a center thickness of a last lens of the first lens group (LG1) and greater than a center thickness of a first lens positioned in the second lens group (LG2). The optical axis distance between the first lens group (LG1) and the second lens group (LG2) may be 35% or less of the optical axis distance of the first lens group (LG1), and may be, for example, in the range of 15% to 35% or 15% to 25% of the optical axis distance of the first lens group (LG1). Here, the optical axis distance of the first lens group (LG1) is the optical axis distance between the object side surface of the lens closest to the object side surface of the first lens group (LG1) and the sensor side surface of the lens closest to the sensor side.

[0063] The optical axis distance between the first lens group (LG1) and the second lens group (LG2) may be 15% or less of the optical axis distance of the second lens group (LG2), for example, in the range of 5% to 15% or 5% to 10%. The optical axis distance of the second lens group (LG2) is the optical axis distance between the object side surface of the lens closest to the object side surface of the second lens group (LG2) and the sensor side surface of the lens closest to the image sensor (300).

[0064] The lens with the smallest effective diameter in the first lens group (LG1) can be arranged between the lenses of the first lens group (LG1). The lens with the smallest effective diameter in the second lens group (LG2) can 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, and can improve chromatic aberration and distortion aberration.

[0065] 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 lens surfaces of the first lens group (LG1) include the first surface to the sixth surface (S1 to S6), and the effective diameters of the first surface to the sixth surface (S1 to S6) may gradually decrease from the first surface (S1) to the third surface (S3), and may gradually increase from the third surface (S3) to the sixth surface (S6). The lens surfaces may include an object side surface and a sensor side surface of each lens. The lens surfaces of the second lens group (LG2) include the seventh surface to the eighteenth surface (S7 to S18), and the effective diameters of the seventh surface to the eighteenth surface (S7 to S18) may increase from the seventh surface (S7) to the eighteenth surface (S18). The difference in effective diameter between the sixth surface and the seventh surface (S6, S7) may be 0.1 mm or less. Therefore, light can be guided to the peripheral portion of the image sensor (300) of about 1 inch through the lens groups (LG1, LG2) having different refractive powers and differences in effective diameters of lens surfaces.

[0066] The effective diameter difference between the lenses having the smallest effective diameter in the first lens group (LG1) and the second lens group (LG2) may be 0.1 mm or more, for example, in the range of 0.1 mm to 0.3 mm. Therefore, incident light may be refracted into an effective area between the first lens group and the second lens group (LG1, LG2), and then refracted to a peripheral portion of the image sensor (300).

[0067] The lens closest to the object side surface among the lenses of the first lens group (LG1) may have a positive (+) refractive power, and the lens closest to the sensor side 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 greater than or less than 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 the same as or different from the number of lenses having a negative (-) refractive power. For example, in Figure 1 In the first embodiment, the number of lenses having positive (+) refractive power may be greater than the number of lenses having negative (-) refractive power, and their ratio may be 6:3. Figure 5 In the second embodiment, the number of lenses having positive (+) refractive power may be greater than the number of lenses having negative (-) refractive power, and their ratio may be 5:4. Figure 8In the third embodiment of the present invention, the number of lenses having positive (+) refractive power may be less than the number of lenses having negative (-) refractive power, and their ratio may be 4:5. Therefore, chromatic aberration between the lenses of the second lens group (LG2) may be corrected. In addition, the ratio of the number of lenses having positive refractive power to the number of lenses having negative refractive power in the optical system (1000) may be 6:3, 5:4 or 4:5, and chromatic aberration between each lens may be corrected.

[0068] In the optical system (1000), the sum of the focal lengths of the lenses having positive refractive power may be smaller than the absolute value of the sum of the focal lengths of the lenses having negative refractive power. Therefore, chromatic aberration and resolution may be improved by using the refractive power of each lens and the positive focal length and the negative focal length.

[0069] Each of the multiple lenses may include an effective area and an ineffective area. The effective area may be an area through which light incident on each of the lenses passes. That is, the effective area may be an effective diameter or an area of ​​an effective diameter in which the incident light is refracted to achieve optical properties. The ineffective area may be arranged around the effective area. The end of the effective area may be defined as an edge or an end. The ineffective area may be an area in which effective light does not enter the multiple lenses. That is, the ineffective area may be a zone that is unrelated to the optical properties. In addition, the end of the ineffective area may be an area fixed to a barrel (not shown) that houses the lens.

[0070] 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, such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The diagonal length of the image sensor (300) may be greater than 4 mm, for example, greater than 4 mm and less than 30 mm. Preferably, the ImgH of the image sensor (300) may be less than TTL.

[0071] The optical system (1000) may include a filter (500). The filter (500) may be disposed between the second lens group (LG2) and the image sensor (300). The filter (500) may be disposed between the image sensor (300) and the lens closest to the sensor among the lens parts (100, 100A, 100B). For example, when the optical system (100) is nine lenses, the filter (500) may be disposed between the image sensor (300) and the ninth lens (109) as the last lens.

[0072] The filter (500) may include an infrared filter. The filter (500) may allow light in a set wavelength band to pass through and filter light in different wavelength bands. When the filter (500) includes an infrared filter, radiant heat emitted from external light can be prevented from being transmitted to the image sensor (300). In addition, the filter (500) may transmit visible light and reflect infrared rays. As another example, a cover glass may also be disposed between the filter (500) and the image sensor (300).

[0073] The optical system (1000) according to an embodiment may include an aperture stop. The aperture stop may be a blocker that adjusts the amount of light incident on the optical system (1000). The aperture stop may be disposed around at least one of the lenses of the first lens group (LG1). For example, the aperture stop may be placed around the object side surface or the sensor side surface of the second lens or the third lens on the object. Alternatively, at least one lens selected from among a plurality of lenses may be used as the aperture stop.

[0074] The straight-line distance from the aperture stop to the sensor side surface of the n-th 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 n-th lens. The optical axis distance from the aperture stop to the sensor side surface of the n-th lens is SD, and the following condition may be satisfied: SD < EFL. 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. The above 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. 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, in the range of 1.1 ≤ F# ≤ 5. When F# is 3 or less, a bright image may be provided. In addition, F# may be less than the entrance pupil diameter (EPD). Therefore, the optical system (1000) has a thin size, can control incident light, and can have improved optical characteristics within the FOV.

[0075] The optical system (1000) according to an embodiment may further include a reflection member (not shown) to change the path of light. 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. Hereinafter, the optical system according to an embodiment will be described in detail.

[0076] Hereinafter, the description of the first to third embodiments will focus on the first embodiment, and the second and third embodiments will be additionally described with respect to configurations different from the first embodiment.

[0077] Reference Figure 1 , Figure 5 as well as Figure 8 In the first to third embodiments, the lens portion (100, 100A, 100B) may include a first lens (101) to a ninth lens (109). The first lens (101) to the ninth lens (109) may be aligned in sequence along an optical axis (OA) of the optical system (1000). Light corresponding to object information may pass through the first lens (101) to the ninth lens (109) and the filter (500), and be incident on the image sensor (300).

[0078] The first lens group (LG1) may include a first lens (101) to a third lens (103), and the second lens group (LG2) may include a fourth lens (104) to a ninth lens (109). The optical axis distance between the third lens (103) and the fourth lens (104) may be the optical axis distance between the first lens group and the second lens group (LG1, LG2), and is set at 0.20 mm or more to suppress an increase in the effective diameters of the fourth lens (104) and the fifth lens (105).

[0079] Among the first lens (101) to the ninth lens (109), the number of lenses having a meniscus shape convex toward the object on the optical axis (OA) may be 4 or more or 6 or less, and may satisfy, for example, n-4 or n-5 of the total number n of lenses. For example, n may be 9. Among all the lenses, the ratio of the meniscus-shaped lenses convex toward the object side surface and the meniscus-shaped lenses convex toward the sensor may be 6:1 or 5:2.

[0080] Reference Figure 1 , Figure 5 as well as Figure 8 The first lens (101) 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 first lens (101) may include plastic or glass. For example, the first lens (101) may be made of plastic.

[0081] On the optical axis (OA), the object-side first surface (S1) of the first lens (101) may have a convex shape, and the sensor-side second surface (S2) may have a concave shape. That is, the first lens (101) may have a meniscus shape that is convex toward the object on the optical axis (OA). Since the first lens (101) has a meniscus shape that is convex toward the object, the amount of incident light can be improved. Alternatively, the first lens (101) may have a lens shape in which both sides are convex. 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. For example, both the first surface (S1) and the second surface (S2) may be aspherical. The aspherical coefficients of the first surface and the second surface (S1, S2) are as follows Figure 4 , Figure 7 as well as Fig.10 It is provided as shown in , where L1 is the first lens (101), L1S1 is the first surface, and L1S2 is the second surface.

[0082] 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 positive refractive power. The second lens (102) may include plastic or glass. For example, the second lens (102) may be made of plastic. In addition, an aperture stop may be provided around a fourth surface (S4) on the sensor side surface of the second lens (102).

[0083] On the optical axis (OA), the object-side third surface (S3) of the second lens (102) may have a convex shape, and the sensor-side fourth surface (S4) may have a convex shape. That is, the second lens (102) may have a shape in which both sides are convex on the optical axis (OA). Alternatively, on the optical axis (OA), the third surface (S3) may have a convex shape, and the fourth surface (S4) may have a concave shape. The third surface (S3) and the fourth surface (S4) of the second lens (102) may be arranged to have no critical point from the optical axis (OA) to the end of the effective area. At least one of the third surface (S3) and the fourth surface (S4) may be an aspherical surface. For example, both the third surface (S3) and the fourth surface (S4) may be aspherical. The aspherical coefficients of the third surface and the fourth surface (S3, S4) are as follows Figure 4 , Figure 7 as well as Fig.10 It is provided as shown in , where L2 is the second lens (102), L2S1 is the third surface, and L2S2 is the fourth surface.

[0084] 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 negative (-) refractive power. The third lens (103) may include plastic or glass. For example, the third lens (103) may be made of plastic. The third lens (103) is located on the sensor side of the second lens (102) where the aperture stop is placed, and has a negative refractive power, and refracts light in a direction away from the optical axis through the aperture stop, so the third lens located on the sensor side of the aperture may have an effective diameter larger than the effective diameter of the second lens. The first lens and the second lens (101, 102) have positive refractive power, and the third lens (103) has negative refractive power, so that chromatic aberration occurring in lenses made of the same material can be corrected.

[0085] On the optical axis (OA), the object-side fifth surface (S5) of the third lens (103) may have a concave shape, and the sensor-side sixth surface (S6) may have a concave shape. That is, the third lens (103) may have a meniscus shape that is convex toward the object 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. The third lens (103) may have a meniscus shape that is convex toward the object. The fifth surface (S5) and the sixth surface (S6) of the third lens (103) may be arranged 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. For example, both the fifth surface (S5) and the sixth surface (S6) may be aspherical. As Figure 4 , Figure 7 as well as Fig.10 The aspheric coefficients of the fifth and sixth surfaces (S5, S6) are provided as shown in , where L3 is the third lens (103), L3S1 is the fifth surface, and L3S2 is the sixth surface.

[0086] 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.

[0087] exist Figure 1 and Figure 3In the first embodiment, the object-side seventh surface (S7) of the fourth lens (104) has a concave shape on the optical axis (OA), and the sensor-side eighth surface (S8) has a convex shape. That is, the fourth lens (104) may have a meniscus shape that is convex toward the sensor on the optical axis (OA). Alternatively, the fourth lens (104) may have a convex shape on both sides of the optical axis or a meniscus shape that is convex toward the object. Alternatively, the fourth lens (104) may have a concave shape on both sides.

[0088] exist Figure 5 and Figure 6 In the second embodiment, the object-side seventh surface (S7) of the fourth lens (104) on the optical axis (OA) has a convex shape, and the sensor-side 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 convex shape on both sides of the optical axis or a meniscus shape that is convex toward the sensor. Alternatively, the fourth lens (104) may have a concave shape on both sides.

[0089] exist Figure 8 and Fig. 9 In the third embodiment, the object-side seventh surface (S7) of the fourth lens (104) has a convex shape on the optical axis (OA), and the sensor-side 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 sides are convex on the optical axis or a meniscus shape that is convex toward the sensor. Alternatively, the fourth lens (104) may have a concave shape on both sides.

[0090] At least one or both of the seventh surface and the eighth surface (S7, S8) of the fourth lens (104) may be configured to have no critical point. At least one of the seventh surface (S7) and the eighth surface (S8) may be an aspherical surface. For example, the seventh surface (S7) and the eighth surface (S8) may be aspherical, such as Figure 4 , Figure 7 as well as Fig.10 Aspheric coefficients are provided as shown in , and L4 is the fourth lens (104), L4S1 is the seventh surface, and L4S2 is the eighth surface. At least one or both of the seventh surface (S7) and the eighth surface (S8) of the fourth lens (104) may be configured to have no critical point.

[0091] In the first to third embodiments, the focal length (absolute value) of the fourth lens (104) may be the largest within the lens portion (100). Therefore, the difference between the focal length of the fourth lens (104) and the focal length of the third lens (103) may be the largest within the lens portion (100). For example, the absolute value of the focal length of the fourth lens (104) is |F4|, the absolute value of the focal length of the third lens (103) is |F3|, and the focal length of the fifth lens (105) is F5. In this case, the following condition may be satisfied: |F3|<|F5| <F4。

[0092] The fifth lens (105) may have positive or negative refractive power on the optical axis (OA). Figure 1 and Figure 3 In the first embodiment, the fifth lens (105) may have positive refractive power. Figure 5 and Figure 6 In the second embodiment, the fifth lens (105) may have positive refractive power. Figure 8 and Fig. 9 In the third embodiment, the fifth lens (105) may have negative refractive power.

[0093] The fifth lens (105) may include plastic or glass. For example, the fifth lens (105) may be made of plastic. Since the first to fifth lenses (101 to 105) include positive and negative refractive powers, chromatic aberration occurring in lenses made of the same material may be corrected.

[0094] exist Figure 1 and Figure 3 In the first embodiment, the object-side ninth surface (S9) of the fifth lens (105) has a concave shape on the optical axis (OA), and the sensor-side tenth surface (S10) may have a convex shape. That is, the fifth lens (105) may have a meniscus shape convex toward the sensor on the optical axis (OA). Alternatively, the fifth lens (105) may have a concave shape or a convex shape on both sides. Alternatively, the fifth lens (105) may have a meniscus shape convex toward the object on the optical axis (OA).

[0095] exist Figure 5 and Figure 6In the second embodiment, the object-side ninth surface (S9) of the fifth lens (105) on the optical axis (OA) may have a concave shape, and the sensor-side tenth surface (S10) may have a convex shape. That is, the fifth lens (105) may have a meniscus shape that is convex toward the sensor on the optical axis (OA). Alternatively, the fifth lens (105) may have a concave shape or a convex shape on both sides. Alternatively, the fifth lens (105) may have a meniscus shape that is convex toward the object on the optical axis (OA).

[0096] exist Figure 8 and Fig. 9 In the third embodiment, the object-side ninth surface (S9) of the fifth lens (105) at the optical axis (OA) may have a convex shape, and the sensor-side tenth surface (S10) may have a concave shape. That is, the fifth lens (105) may have a meniscus shape that is convex toward the object on the optical axis (OA). Alternatively, the fifth lens (105) may have a concave shape or a convex shape on both sides. Alternatively, the fifth lens (105) may have a meniscus shape that is convex toward the sensor on the optical axis (OA).

[0097] At least one or both of the ninth surface (S9) and the tenth surface (S10) of the fifth lens (105) may be configured to have no critical point. At least one of the ninth surface (S9) and the tenth surface (S10) may be an aspherical surface. For example, the ninth surface (S9) and the tenth surface (S10) may be aspherical surfaces, such as Figure 4 , Figure 7 as well as Fig.10 The aspherical coefficient is provided as shown in , and L5 is the fifth lens (105), L5S1 is the ninth surface, and L5S2 is the tenth surface.

[0098] The sixth lens (106) may have positive (+) refractive power or negative (-) refractive power on the optical axis (OA). Figure 1 and Figure 3 In the first embodiment, the sixth lens (106) may have positive refractive power. Figure 5 and Figure 6 In the second embodiment, the sixth lens (106) may have positive refractive power. Figure 8 and Fig. 9 In the third embodiment, the sixth lens (106) may have positive refractive power. The sixth lens (106) may include plastic or glass. For example, the sixth lens (106) may be made of plastic.

[0099] exist Figure 1 and Figure 3In the first embodiment, the object-side eleventh surface (S11) of the sixth lens (106) on the optical axis (OA) has a convex shape, and the sensor-side twelfth surface (S12) may have a convex shape. That is, the sixth lens (106) may have a shape in which both sides are convex on the optical axis (OA). Alternatively, the sixth lens (106) may have a meniscus shape that is convex toward the sensor on the optical axis. Alternatively, the sixth lens (106) may have a concave shape on both sides. Alternatively, the sixth lens (106) may have a meniscus shape that is convex toward the object.

[0100] exist Figure 5 and Figure 6 In the second embodiment, the object-side eleventh surface (S11) of the sixth lens (106) on the optical axis (OA) has a concave shape, and the sensor-side twelfth surface (S12) may have a convex shape. That is, the sixth lens (106) may have a meniscus shape that is convex toward the sensor on the optical axis (OA). Alternatively, the sixth lens (106) may have a convex shape or a concave shape on both sides of the optical axis. Alternatively, the sixth lens (106) may have a meniscus shape that is convex toward the object.

[0101] exist Figure 8 and Fig. 9 In the third embodiment, the object-side eleventh surface (S11) of the sixth lens (106) on the optical axis (OA) has a concave shape, and the sensor-side twelfth surface (S12) may have a convex shape. That is, the sixth lens (106) may have a meniscus shape that is convex toward the sensor on the optical axis (OA). Alternatively, the sixth lens (106) may have a convex shape or a concave shape on both sides of the optical axis. Alternatively, the sixth lens (106) may have a meniscus shape that is convex toward the object.

[0102] At least one or both of the eleventh surface (S11) and the twelfth surface (S12) of the sixth lens (106) may be arranged to have no critical point from the optical axis (OA) to the end of the effective area. At least one of the eleventh surface (S11) and the twelfth surface (S12) may be an aspherical surface. For example, the eleventh surface (S11) and the twelfth surface (S12) may be aspherical, such as Figure 4 , Figure 7 as well as Fig.10 The aspherical coefficient is provided as shown in , and L6 is the sixth lens (106), L6S1 is the eleventh surface, and L6S2 is the twelfth surface.

[0103] The seventh lens (107) may have positive (+) or negative (-) refractive power on the optical axis (OA) and is an n-2 th lens. Figure 1 and Figure 3 In the first embodiment, the seventh lens (107) may have positive refractive power. Figure 5 and Figure 6 In the second embodiment, the seventh lens (107) may have negative refractive power. Figure 8 and Fig. 9 In the third embodiment, the seventh lens (107) may have positive refractive power. The seventh lens (107) may include plastic or glass. For example, the seventh lens (107) may be made of plastic. Since the fifth to ninth lenses (105, 106, 107, 108, 109) include positive refractive power and negative refractive power, they can correct chromatic aberration occurring in lenses made of the same material. In addition, the following condition may be satisfied: |F6| <F7。

[0104] On the optical axis (OA), the object-side thirteenth surface (S13) of the seventh lens (107) may have a concave shape, and the sensor-side fourteenth surface (S14) may have a concave shape. That is, the seventh lens (107) may have a shape in which both sides are concave on the optical axis (OA). Alternatively, the seventh lens (107) may have a meniscus shape that is convex toward the sensor on the optical axis. Alternatively, the seventh lens (107) may have a convex shape on both sides.

[0105] At least one of the thirteenth surface (S13) and the fourteenth surface (S14) of the seventh lens (107) may be an aspherical surface. For example, the thirteenth surface (S13) and the fourteenth surface (S14) may be an aspherical surface, such as Figure 4 , Figure 7 as well as Fig.10 The aspherical coefficient is provided as shown in , and L7 is the seventh lens (107), L7S1 is the thirteenth surface, and L7S2 is the fourteenth surface.

[0106] The eighth lens (108) is an n-1th lens and may have negative or positive refractive power on the optical axis (OA), and may have, for example, positive refractive power. The eighth lens (108) may include plastic or glass, and may be made of, for example, plastic.

[0107] The eighth lens (108) may include a fifteenth surface (S15) defined as an object side surface and a sixteenth surface (S16) defined as a sensor side surface. 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 is convex toward the object on the optical axis (OA). Alternatively, the eighth lens (108) may have a meniscus shape that is convex toward the sensor on the optical axis or a shape that is concave on both sides.

[0108] like Figure 2 As shown in , the fifteenth and sixteenth surfaces (S15, S16) of the eighth lens (108) may have critical points (P1, P2). The fifteenth and sixteenth surfaces (S15, S16) may be aspherical, and as shown in Figure 4 , Figure 7 as well as Fig.10 Aspherical coefficients are provided as shown in , L8 is the eighth lens (108), L8S1 is the fifteenth surface, and L8S2 is the sixteenth surface.

[0109] like Figure 2 As shown in , the first critical point (P1) of the fifteenth surface (S15) of the eighth lens (108) can be located at a position greater than 79% of the effective radius relative to the optical axis (OA), for example, in the range of 79% to 99%, or in the range of 84% to 94%. The second critical point (P2) of the sixteenth surface (S16) can be located at a position greater than 72% of the effective radius (r82) based on the optical axis (OA), for example, in the range of 72% to 92%, or in the range of 77% to 87%. The second critical point (P2) can be located at the edge instead of the first critical point (P1), and the separation distance between the first critical point and the second critical point (P1, P2) can be 0.9 mm or less. Therefore, the sixteenth surface (S16) can further refract the light incident on the fifteenth surface (S15) in the edge direction, thereby reducing TTL.

[0110] Here, the critical point is a point at which the sign of the slope value relative to the optical axis (OA) and the direction perpendicular to the optical axis (OA) changes from positive (+) to negative (-) or from negative (-) to positive (+), and may mean a point at which the slope value is zero. In addition, the critical point may be a point at which the slope value of a tangent line passing through the lens surface increases and then decreases, or a point at which the slope value decreases and then increases.

[0111] The ninth lens (109) is an nth lens and may have negative refractive power on the optical axis (OA). The ninth lens (109) may include plastic or glass. For example, the ninth lens (109) may be made of plastic. The ninth lens (109) may be the lens closest to the sensor or the last lens in the optical system (1000).

[0112] The ninth lens (109) may include a seventeenth surface (S17) defined as an object side surface and an eighteenth surface (S18) defined as a sensor side surface. On the optical axis (OA), the seventeenth surface (S17) may have a convex shape, and the eighteenth surface (S18) may have a concave shape. That is, the ninth lens (109) may have a meniscus shape convex toward the object on the optical axis (OA). Alternatively, the ninth lens (109) may have a meniscus shape convex from the optical axis toward the sensor or a shape concave on both sides.

[0113] At least one or both of the seventeenth surface and the eighteenth surface (S17, S18) of the ninth lens (109) may have a critical point. The seventeenth surface and the eighteenth surface (S17, S18) may be aspherical, and as Figure 4 , Figure 7 as well as Fig.10 Aspherical coefficients are provided as shown in , L9 is the ninth lens (109), L9S1 is the seventeenth surface, and L9S2 is the eighteenth surface.

[0114] like Figure 2 As shown in , the third critical point (P3) of the seventeenth surface (S17) of the ninth lens (109) can be located at a distance of 52% or less of the effective radius based on the optical axis (OA), for example, in the range of 32% to 52%, or in the range of 37% to 47%. The fourth critical point (P4) of the eighteenth surface (S18) can be located within a range of 73% or more of the effective radius (r92) based on the optical axis (OA), for example, in the range of 73% to 93%, or in the range of 78% to 88%. The third critical point (P3) can be located closer to the optical axis (OA) than the first critical point, the second critical point, and the fourth critical point (P1, P2, P4), and the separation distance between the third critical point and the fourth critical point (P3, P4) can be greater than 1 mm. 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.

[0115] Considering the optical characteristics of the optical system (1000), the positions of the critical points (P1, P2, P3, P4) of the eighth lens and the ninth lens (108, 109) are preferably positioned to satisfy the above-mentioned range. In detail, it is desirable that the positions of the critical points satisfy the above-mentioned 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 embodiment can have improved optical characteristics even in the central area and peripheral area of ​​the FOV.

[0116] like Figure 2 As shown in , the distance from the optical axis (OA) to the end of the effective area of ​​each of the fifteenth surface (S15) and the sixteenth surface (S16) of the eighth lens (108) is an effective radius, which can be defined as r81 and r82. The distance from the optical axis (OA) to the end of the effective area of ​​each of the seventeenth surface (S17) and the eighteenth surface (S18) of the ninth lens (109) is an effective radius, and can be defined as r91 and r92.

[0117] The distances from the optical axis (OA) to the fifteenth, sixteenth, seventeenth and eighteenth (S15, S16, S17, S18) critical points (P1, P2, P3, P4) may be defined as follows.

[0118] Inf81: The straight-line distance from the center of the fifteenth surface (S15) to the first critical point (P1)

[0119] Inf82: The straight-line distance from the center of the sixteenth surface (S16) to the second critical point (P2)

[0120] Inf91: straight-line distance from the center of the seventeenth surface (S17) to the third critical point (P3) Inf92: straight-line distance from the center of the eighteenth surface (S18) to the fourth critical point (P4) The distance from the center of each lens surface to the critical point can have the following relationship.

[0121] Inf81 <Inf82

[0122] Inf91 <Inf92

[0123] Inf91< <Inf81<Inf82<Inf92

[0124] (Inf82-Inf81)<(Inf92-Inf91)

[0125] The effective radius (r81, r82, r91, r92) from the optical axis and the distance (Inf81, Inf82, Inf91, Inf92) to the critical point (P1, P2, P3, P4) can satisfy the following formula.

[0126] 0.80≤Inf81 / r81≤0.98

[0127] 0.74≤Inf82 / r82≤0.91

[0128] 0.38≤Inf91 / r91≤0.46

[0129] 0.74≤Inf92 / r92≤0.91

[0130] The positions of the first critical point and the second critical point (P1, P2) may be located at 1 mm or more from the optical axis (OA), for example, in the range of 1 mm to 3 mm, and the third critical point (P3) may be located at a distance of 1.5 mm or less from the optical axis (OA), for example, in the range of 0.7 mm to 1.5 mm. The fourth critical point (P4) may be located at a position of 2.2 mm or more from the optical axis, for example, in the range of 2.2 mm to 3.2 mm. Therefore, the eighth lens and the ninth lens (108, 109) may refract incident light toward the central portion and the peripheral portion.

[0131] On the optical axis,

[0132] The first surface and the second surface (S1, S2) of the first lens (101) have radii of curvature L1R1 and L1R2,

[0133] The radii of curvature of the third and fourth surfaces (S3, S4) of the second lens (102) are L2R1 and L2R2,

[0134] The curvature radii of the fifth and sixth surfaces (S5, S6) of the third lens (103) are L3R1 and L3R2,

[0135] The curvature radii of the seventh and eighth surfaces (S7, S8) of the fourth lens (104) are L4R1 and L4R2,

[0136] The curvature radii of the ninth and tenth surfaces (S9, S10) of the fifth lens (105) are L5R1 and L5R2,

[0137] The curvature radii of the eleventh and twelfth surfaces (S11, S12) of the sixth lens (106) are L6R1 and L6R2,

[0138] The curvature radii of the thirteenth and fourteenth surfaces (S13, S14) of the seventh lens (107) are L7R1 and L7R2,

[0139] The curvature radii of the sixteenth surface and the sixteenth surface (S15, S16) of the eighth lens (108) are L8R1 and L8R2,

[0140] The curvature radii of the seventeenth and eighteenth surfaces (S17, S18) of the ninth lens (109) may be defined as L9R1 and L9R2. The curvature radii may satisfy at least one of the following conditions 1 to 9 to improve aberration characteristics of the optical system.

[0141] Condition 1: (L1R1*L1R2)<|L2R2|

[0142] Condition 2: (L1R1+L1R2)<(|L2R2|-L2R1)

[0143] Condition 3: (L3R1*L3R2)<|L2R2|

[0144] Condition 4: |L4R2|<|L4R1| (where 100<|L4R1|, |L4R2|)

[0145] Condition 5: |L5R2|<|L5R1|<|L4R2| (where 40<|L5R1|, |L5R2|)

[0146] Condition 6: |L6R2|<|L4R1|<|L6R1| (where 1000<|L6R1|)

[0147] Condition 7: |L7R1|<|L7R2|<|L2R2| (where L7R1<0)

[0148] Condition 8: L8R1*L8R2<(|L7R1|*|L7R2|) (Here, the following conditions can be satisfied: L8R1 <L8R2)

[0149] Condition 9: L9R1+L9R2 <L8R2

[0150] Condition 10: L9R1*L9R2 <L1R1+L1R2

[0151] Condition 11: (L1R1+L1R2+L2R1+L7R2)<|L2R2| (where L2R2<0)

[0152] On the optical axis (OA), the average curvature radius of any one of the first lens and the ninth lens (101, 109) can be the smallest in the optical system, and the difference between the curvature radii of the first lens and the ninth lens (101, 109) can be 2 mm or less. The average value of the curvature radii (absolute values) of the third surface and the fourth surface (S3, S4) of the third lens (103) can be the largest in the optical system (1000). By setting the curvature radius of each lens, good optical performance can be provided at the focal length of each lens.

[0153] The effective diameters of the first to ninth lenses (101 to 109) may be defined as CA1 to CA9. The effective diameter (CA9) of the ninth lens (108) may have a maximum effective diameter and may be 6 mm or more. The effective diameter (CA9) of the ninth lens (109) is an average of the effective diameters of the object side surface and the sensor side surface. The effective diameter (CA9) of the ninth lens (109) may be greater than twice the radius of curvature of the object side surface (S1) of the first lens (101).

[0154] On the optical axis,

[0155] The effective diameters of the first surface and the second surface (S1, S2) of the first lens (101) are CA11 and CA12,

[0156] The effective diameters of the third and fourth surfaces (S3, S4) of the second lens (102) are CA21 and CA22,

[0157] The effective diameters of the fifth and sixth surfaces (S5, S6) of the third lens (103) are CA31 and CA32,

[0158] The effective diameters of the seventh and eighth surfaces (S7, S8) of the fourth lens (104) are CA41 and CA42,

[0159] The effective diameters of the ninth and tenth surfaces (S9, S10) of the fifth lens (105) are CA51 and CA52,

[0160] The effective diameters of the eleventh and twelfth surfaces (S11, S12) of the sixth lens (106) are CA61 and CA62,

[0161] The effective diameters of the thirteenth and fourteenth surfaces (S13, S14) of the seventh lens (107) are CA71 and CA72,

[0162] The effective diameters of the fifteenth and sixteenth surfaces (S15, S16) of the eighth lens (108) are CA81 and CA82,

[0163] The effective diameters of the seventeenth and eighteenth surfaces (S17, S18) of the ninth lens (109) may be defined as CA91 and CA92. These effective diameters are factors that affect the aberration characteristics of the optical system and may satisfy at least one of the following conditions.

[0164] Condition 1: CA22 ≤ CA31 <CA32≤CA12<CA11

[0165] Condition 2: CA51 <CA52<CA61<CA62

[0166] Condition 3: CA62 <CA72<CA81<CA82<CA91<CA92

[0167] Condition 4: CA31-CA22 <CA41-CA32

[0168] Condition 5: CA41+CA42 <CA92

[0169] Condition 6: L9R1+L9R2 <CA92

[0170] The effective diameter of the lens may be the smallest for the second lens (102) and the largest for the ninth lens (109). The effective diameter of the fourth surface (S4) or the fifth surface (S5) may be the smallest, and the effective diameter of the eighteenth surface (S18) may be the largest. The effective diameter of the ninth lens (109) 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 the incident light.

[0171] In the optical system, the number of lenses having a refractive index greater than 1.6 may be 2 or more, or 3 or more, and may be less than the number of lenses having a refractive index of 1.6 or less. In the optical system, the number of lenses having a refractive index of 1.6 or less may be 5 or more, or 6 or less. The average refractive index of the first to ninth lenses (101 to 109) may be 1.50 or greater. 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, for example 5 or more. The average Abbe number of the first to ninth lenses (101 to 109) may be 40 or greater. By setting the refractive index and Abbe number of each lens, the influence of chromatic aberration can be controlled.

[0172] Reference Figure 2, the back focal length (BFL) is the optical axis distance from the image sensor (300) to the last lens. That is, the BFL is the distance between the image sensor (300) on the optical axis and the eighteenth sensor-side surface (S18) of the ninth lens (109).

[0173] CT8 is the central thickness or optical axis thickness of the eighth lens (108), and ET8 is the end or edge thickness of the effective area of the eighth lens (108). CT9 is the central thickness or optical axis thickness of the ninth lens (109). CG8 is the optical axis distance between the eighth lens (108) and the ninth lens (109). That is, the optical axis distance (CG8) between the eighth lens (108) and the ninth lens (109) 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 lens (101) to the ninth lens (109) can be defined as CT1 to CT9, and the optical axis distances between the first lens to the ninth lens can be defined as CG1 to CG8. In addition, the edge thickness of each lens can be defined as ET1 to ET9. Here, the edge thickness can be the distance between the effective areas of each lens in the direction of the optical axis.

[0174] CG8 can be greater than the optical axis distance between the second lens and the third lens (102, 103). CG8 can be less than the central thickness of each of the sixth lens and the eighth lens (106, 108). CG8 can be the largest among the optical axis distances between two adjacent lenses. CG8 can be 20% or less of the optical axis distance from the first surface (S1) of the first lens (101) to the eighteenth surface (S18) of the ninth lens (109), for example, in the range of 5% to 20%. Among the first lens to the ninth lens (101 to 109), the lens with the largest central thickness is the ninth lens (109). The central thickness (CT1) of the ninth lens (109) can be greater than the central thicknesses of the second lens and the eighth lens (102, 108), and can satisfy the following conditions: CT1 < CG8 < CT9 and CG8 < CT8. A thin optical system with improved optical performance can be provided by the central thicknesses of the eighth lens and the ninth lens (108, 109) and the optical axis distance between the eighth lens and the ninth lens (108, 109).

[0175] In addition, the following formula can be satisfied: CG1 < CT3 < CT2. Therefore, the difference between the effective diameters (CA1, CA2, CA3) of each of the first lens to the third lens (101, 102, 103) can be reduced by reducing the central distance (CG1) between the first lens and the second lens (101, 102). The following formula can be satisfied: CA3 - CA2 < CA1 - CA2.

[0176] The center distance (CG8) between the eighth lens (108) and the ninth lens (109) is the largest among the center distances between the lenses, and at least one of the optical axis distances (CG2) between the second lens and the third lens (102, 103), the optical axis distance (CG4) between the fourth lens and the fifth lens (104, 105), or the optical axis distance (CG6) between the sixth lens and the seventh lens (106, 107) is the smallest among the center distances between the lenses. Here, the center distance (CG3) between the third lens and the fourth lens (103, 104) is greater than the center distances between other adjacent lenses, and can satisfy, for example, the following conditions: CG1 < CG3, CG2 < CG3, and CG4 < CG3.

[0177] The lens having the largest center thickness can be the last lens, i.e., the ninth lens (109), and the lens having the smallest center thickness can be any one of the fourth lens and the fifth lens (104, 105), and can be, for example, the fourth lens (104). The center thickness of the second lens (102) can be greater than the center thickness of each of the first lens, the third lens, the fifth lens, the sixth lens, and the seventh lens.

[0178] The largest center thickness among the lenses (101 to 109) can be 4 times or less the smallest center thickness, for example, in the range of 1.5 times to 4 times or 2.7 times to 3.5 times. The number of lenses having a center thickness less than 0.4 mm among the lenses can be greater than the number of lenses having a center thickness of 0.4 mm or more, and is five or more. The average center thickness of the lenses can be less than 0.4 mm. An optical system (1000) having an image sensor (300) with a size of about 1 inch can be provided in a structure having a thin thickness.

[0179] The sum of the center thicknesses (CT) of the first lens to the ninth lens (101 to 109) is ΣCT, the sum of the center distances between the first lens to the ninth lens (101 to 109) is ΣCG, and the average value of the center thicknesses (CT) of the first lens to the ninth lens (101 to 109) is CT_AVER, and any one of the following conditions can be satisfied.

[0180] Condition 1: ΣCG < ΣCT

[0181] Condition 2: 1.2 < (ΣCT - ΣCG)

[0182] Condition 3: 0.32 < CT_AVER < 0.39

[0183] The difference between the sum of the center thicknesses (ΣCT) of the first to ninth lenses (101 to 109) and the sum of the center distances (ΣCG) between the first to ninth lenses (101 to 109) may be 40% or more of the sum of the center thicknesses (ΣCT), or 80% or more of the sum of the center distances (ΣCG). Therefore, the optical system (1000) can control incident light and have improved aberration characteristics and resolution.

[0184] In the case where the focal length of each lens (101 to 109) is defined as F1 to F9, at least one of the following conditions may be satisfied.

[0185] Condition 1: F1<|F4|

[0186] Condition 2: F2 <F1<|F4|

[0187] Condition 3: F8<|F5|<|F4|

[0188] Condition 4: (F1*2)<|F4|

[0189] By adjusting the focal length, the resolution may be affected. When the focal length is described as an absolute value, the focal length (F4) of the fourth lens (104) may be the largest among the lenses, and the focal length of the second lens (102) or the ninth lens (109) may be the smallest. The maximum focus distance may be 50 times or more of the minimum focus distance. The refractive powers of the first to ninth lenses (101-109) may be distributed to minimize chromatic aberration.

[0190] When the refractive indices of each of the lenses (101 to 109) are n1 to n9 and the Abbe numbers of each of the lenses (101 to 109) are v1 to v9, the refractive indices may satisfy the following conditions: n1 < n3, and the Abbe numbers may satisfy the following conditions: v1 > v3. n1, n2, n4, n5, n8, n9 are less than 1.6 and may have a difference of less than 0.2 from each other, and n3, n6, n7 are greater than 1.60. The Abbe numbers v1, v2, v4, v5, v8, and v9 may be 45 or greater and may have a difference of 15 or less from each other, and v3, v6, and v7 may be less than 45, for example 30 or less. Accordingly, the optical system (1000) may have improved chromatic aberration control characteristics. Preferably, the following condition may be satisfied: v3 * n3 < v1 * n1. Further, the following condition may be satisfied: v3 * n3 < v2 * n2. In order to minimize chromatic aberration, the refractive index of the third lens (103) may be set relatively high, and the refractive indices of the first and second lenses (101, 102) may be set relatively low. Further, in order to minimize chromatic aberration, the Abbe number (v3) of the third lens (103) may be set relatively low, and the Abbe numbers (v1, v2) of the first and second lenses (101, 102) may be set relatively high.

[0191] The first lens to the ninth lens (101 to 109) are made of a plastic material and all have aspherical surfaces, such that spherical aberration and chromatic aberration can be corrected, and lenses having a high Abbe number and lenses having a low refractive index are appropriately arranged. Accordingly, a small lens optical system with high resolution can be provided by compensating for chromatic aberration and improving the performance between the lenses.

[0192] The optical system (1000) according to the embodiment disclosed above may satisfy at least one or two of the formulas described below. Accordingly, the optical system (1000) according to the embodiment may have improved optical characteristics. For example, when the optical system (1000) satisfies at least one formula, the optical system (1000) may effectively control aberration characteristics such as chromatic aberration and distortion aberration, and may have good optical performance not only in the central portion but also in the peripheral portion of the FOV. The optical system (1000) may have improved resolution and may have a thinner and more compact structure.

[0193] In the following, the center thickness of the first lens to the ninth lens (101 to 109) can be defined as CT1 to CT9, the edge thickness can be defined as ET1 to ET8, and the optical axis distance between two adjacent lenses can be defined as the first lens and the second lens. The distance between the first lens and the second lens to the distance between the eighth lens and the ninth lens can be defined as CG1 to CG8. The effective diameters of the first lens to the ninth lens (101 to 109) can be defined as CA1 to CA9, and the effective diameters from the object side surface and the sensor side surface of the first lens (101) to the object side surface and the sensor side surface of the eighth lens (108) can be defined as CA11, CA12 to CA91, CA92. The units of the thickness, distance and effective diameter values ​​are mm.

[0194] [Formula 1] <CT1 / CT2<1

[0195] In Formula 1, when the center thickness (CT1) of the first lens (101) and the center thickness (CT2) of the second lens (102) are satisfied, the optical system (1000) can improve the aberration characteristics. Preferably, Formula 1 can satisfy: 0.2 <CT1 / CT2<0.9。

[0196] [Formula 2] <CT3 / ET3<3

[0197] In Formula 2, when the center thickness (CT3) of the third lens (103) and the edge thickness (ET3) of the third lens (103) are satisfied, the optical system (1000) can have improved chromatic aberration control characteristics. Preferably, Formula 2 can satisfy: <CT3 / ET3<1。

[0198] [Formula 2-1]1 <CT1 / ET1<2

[0199] [Formula 2-2]1 <CT2 / ET2<5

[0200] [Formula 2-3] CT1 <CT2

[0201] [Formula 2-4] 0.8 <CT4 / ET4<1.8

[0202] [Formula 2-5] 0.8 <CT5 / ET5<1.5

[0203] [Formula 2-6] 0.5 <CT6 / ET6<1.5

[0204] [Formula 2-7] 0.8 <CT7 / ET7<2

[0205] [Formula 2-8] 0.5 <CT8 / ET8<1.5

[0206] [Formula 2-9]0 <CT9 / ET9<1.5

[0207] [Formula 2-10] 0.5 <SD / TD<1

[0208] If the ratio of each of the center thicknesses (CT2 to CT9) of the second to ninth lenses (102 to 109) to each of the edge thicknesses (ET2 to ET9) is satisfied in equations 2-1 to 2-9, the optical system (1000) can have improved chromatic aberration control characteristics. In other words, since the range of the center thickness relative to the edge thickness of each lens (101 to 109) is set, and the difference between the outermost thickness and the center thickness of each lens is set, distortion aberration can be corrected and a wide-angle image can be obtained. In addition, the difference between the edge thickness and the center thickness of the first lens (101) can be set to be greater than the difference between the outermost thickness and the center thickness of the last lens (109) to correct the distortion aberration of the light transmitted to the image sensor (300).

[0209] SD is an optical axis distance from the aperture stop to the eighteenth surface (S18) on the sensor side of the ninth lens (109), and TD is an optical axis distance from the first surface (S1) on the object side of the first lens (101) to the eighteenth surface (S18) on the sensor side of the ninth lens (109). The aperture stop may be provided around the sensor side surface of the second lens (102). When the optical system (1000) according to the embodiment satisfies equation 2-9, the optical system (1000) may correct chromatic aberration.

[0210] [Formula 2-10] 0<|F_LG1 / F_LG2|<1

[0211] F_LG1 is the focal length of the first lens group (LG1), and F_LG2 is the focal length of the second lens group (LG2). When the optical system (1000) according to the embodiment satisfies Formula 2-10, the optical system (1000) can correct chromatic aberration. That is, when the value of Formula 2-10 is close to 1, the distortion aberration can be reduced. Preferably, the following condition can be satisfied: 0<|F_LG1| / |F_LG2|<0.5.

[0212] [Formula 3] 10 <TTL / CT_AVER<25

[0213] In Formula 3, CT_AVER is the average value of the center thickness of the first lens to the ninth lens (101 to 109), and when the center thickness and the total length (TTL) of the lens satisfy the above range, a thin optical system can be provided. Preferably, Formula 3 can satisfy: 12 <TTL / CT_AVER<20。

[0214] [Formula 3-1]1 <TTL / CT_AVER / n<3

[0215] In Formula 3-1, n is the total number of lenses, and when the center thickness and the total length (TTL) of the lenses compared to the number of lenses satisfy the above ranges, a slim optical system can be provided.

[0216] [Formula 3-2] CT2<(CT3+CT4+CT5)<(2*CT2)

[0217] In Formula 3-2, when the sum of the center thicknesses (CT3, CT4, CT5) of the third lens, the fourth lens, and the fifth lens (103, 104, 105) and the center thickness (CT2) of the second lens (102) satisfy the above range, the optical system (1000) can have improved chromatic aberration control characteristics. Preferably, the following conditions can be satisfied: CT1 <CT2<CT8。

[0218] [Formula 3-3]CG8 <CT8

[0219] In Formula 3-3, when the optical axis distance (CG8) between the eighth lens and the ninth lens (108, 109) and the center thickness (CT8) of the eighth lens satisfy the above ranges, the optical system (1000) can have improved chromatic aberration control characteristics.

[0220] [Equation 4] 1.60 <n3

[0221] In Formula 4, n3 means the refractive index of the third lens (103) at the d-line. When the optical system (1000) according to the embodiment satisfies Formula 4, the optical system (1000) can improve chromatic aberration characteristics.

[0222] [Formula 4-1]

[0223] 1.50 <n1<1.60

[0224] 1.50 <n2<1.60

[0225] 1.50 <n4<1.60

[0226] 1.50 <n5<1.60

[0227] In Formula 4-1, n1, n2, n4, and n5 are the refractive indices at the d-line of the first lens, the second lens, the fourth lens, and the fifth lens (101, 102, 104, 105). When the optical system (1000) according to the embodiment satisfies Formula 4-1, the influence on the TTL of the optical system (1000) can be suppressed.

[0228] [Formula 4-2]

[0229] 0.3≤|n7-n8|≤0.1

[0230] 0≤|n8-n9|≤0.05

[0231] In Formula 4-2, n7, n8, and n9 are the refractive indices of the seventh lens, the eighth lens, and the ninth lens (107, 108, 109) at the d line. When the optical system (1000) according to the embodiment satisfies Formula 4-2, the optical system (1000) can improve chromatic aberration characteristics.

[0232] [Formula 5] <n1 / n3<1.5

[0233] In Formula 5, when the refractive indices (n1, n2) at the d-line of the first lens and the third lens (101, 103) satisfy the above range, the optical system can improve the resolution of the incident light. Preferably, the following conditions can be satisfied: 0.5 <n1 / n3<1。

[0234] [Formula 6] <n3 / n4<1.5

[0235] In Formula 6, when the refractive index (n3, n5) at the d-line of the third lens and the fourth lens (103, 104) satisfies 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: 1 <n3 / n4<1.5。

[0236] [Equation 7] (v3*n3)<(v1*n1)

[0237] In Formula 7, when the refractive index (n1) and the Abbe number (v1) of the first lens (101) and the refractive index (n3) and the Abbe number (v3) of the third lens (103) are satisfied, the dispersion of light transmitted through the first lens and the third lens (101, 103) can be controlled.

[0238] [Formula 8] <Inf91 / Inf92<1

[0239] In Formula 8, a distance (Inf91) from the optical axis (OA) to the critical point (P3) of the seventeenth surface (S17) of the ninth lens (109) and a distance (Inf92) from the optical axis (OA) to the critical point (P4) of the eighteenth surface (S18) can be set, and when this is satisfied, the curvature aberration of the ninth lens (109) can be controlled. Formula 8 can satisfy: 0.2 <Inf91 / Inf92<0.8。

[0240] [Equation 9] <Inf81 / Inf82<1.5

[0241] In Formula 9, a distance (Inf81) from the optical axis (OA) to the critical point (P1) of the fifteenth surface (S15) of the eighth lens (107) and a distance (Inf82) from the critical point (P2) of the sixteenth surface (S16) can be set, and when this is satisfied, the curvature aberration of the eighth lens (108) can be controlled. Formula 9 can satisfy: 0.5 <Inf81 / Inf82<1。

[0242] [Equation 10] 0.5 <Inf82 / Inf92<1.5

[0243] When equation 10 is satisfied, the curvature aberration of the eighth lens and the ninth lens can be controlled. Equation 10 can satisfy: 0.7 <Inf82 / Inf92<1。

[0244] [Equation 11] <CG8 / (CT8+CT9)<1

[0245] In Formula 11, when the optical axis distance (CG8) between the eighth lens and the ninth lens (108, 109) is less than the sum of the center thicknesses of the adjacent lenses, good optical performance can be achieved even in the central part and the peripheral part of the FOV. In addition, the optical system (1000) can reduce distortion and have improved optical performance. Preferably, Formula 11 can satisfy: 0.2 <CG8 / (CT8+CT9)<0.6。

[0246] [Equation 12] <CG8 / (CG5+CG6)<3

[0247] In Formula 12, when the sum of the optical axis distances (CG5, CG6) between the fifth lens (105) to the seventh lens (107) and the optical axis distance (CG8) between the eighth lens and the ninth lens (108, 109) 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 12 can satisfy: <CG8 / (CG5+CG6)<1.5。

[0248] [Equation 13] <CT1 / CT8<1.5

[0249] In Formula 13, when the center thickness (CT1) of the first lens (101) and the center thickness (CT8) of the eighth lens (108) are satisfied, the optical system (1000) can have improved aberration characteristics. In addition, the optical system (1000) has good optical performance at a set FOV and can control TTL. Preferably, Formula 13 can satisfy: <CT1 / CT8<1。

[0250] [Equation 14] <CT7 / CT8<1.5

[0251] In Formula 14, when the center thickness (CT7) of the seventh lens (107) and the center thickness (CT8) of the eighth lens (108) are satisfied, the optical system (1000) can reduce the manufacturing accuracy of the seventh lens (107) and the eighth lens (108), and improve the optical performance of the central part and the peripheral part of the FOV. Preferably, Formula 13 can satisfy: 0.3 <CT7 / CT8<1。

[0252] [Equation 15] <L8R2 / L9R1<10

[0253] In Formula 15, L8R2 means the radius of curvature on the optical axis of the sixteenth surface (S16) of the eighth lens (108) (unit: mm), and L9R1 means the radius of curvature on the optical axis of the seventeenth surface (S17) of the ninth lens (109) (unit: mm). When the optical system (1000) according to the embodiment satisfies Formula 14, the aberration characteristics of the optical system (1000) can be improved. Preferably, Formula 15 can satisfy: <L8R2 / L9R1<5。

[0254] [Formula 16] 0<(CT8-CG8) / (CT8)<1

[0255] When Formula 16 satisfies the center distance (CG8) between the eighth lens and the ninth lens (108, 109) and the center thickness (CT8) of the eighth lens (108), the optical system (1000) can reduce the occurrence of distortion and have improved optical performance. When Formula 16 is satisfied, an optical path passing through the eighth lens and the ninth lens (108, 109) can be set. When the optical system (1000) according to an embodiment satisfies Formula 16, the optical performance in the central part and the peripheral part of the FOV can be improved. Formula 16 can preferably satisfy: 0<(CT8-CG8) / (CT8)<0.5. Here, when comparing the center distances (CG) between the sixth lens, the seventh lens, the eighth lens and the ninth lens, the following conditions can be satisfied: CG7 <CG6<CG8。

[0256] [Equation 17] <CA11 / CA32<2

[0257] In Formula 17, CA11 means an effective diameter (clear aperture: CA) of the first surface (S1) of the first lens (101), and CA32 means an effective diameter of the sixth surface (S6) of the third lens (103). When the optical system (1000) according to the embodiment satisfies Formula 17, the optical system (1000) can control the light path incident on the first lens group (LG1) and emitted from the first lens group (LG1), and has improved aberration control characteristics. Formula 17 may preferably satisfy: 1 <CA11 / CA32<1.5。

[0258] [Formula 18]1 <CA92 / CA31<5

[0259] In Formula 18, CA31 means the effective diameter of the fifth surface (S5) of the third lens (103), and CA92 means the effective diameter of the eighteenth surface (S18) of the ninth lens (109). When the optical system (1000) according to the embodiment satisfies Formula 18, the optical system (1000) can control the path of light incident on the second lens group (LG2) and improve aberration characteristics. Preferably, Formula 18 can satisfy: 2 <CA92 / CA31<3。

[0260] [Equation 19] 0.5 <CA32 / CA41<1.5

[0261] In Formula 19, when the effective diameter (CA32) of the sixth surface (S6) of the third lens (103) and the effective diameter (CA41) of the seventh surface (S7) of the fourth lens (104) are satisfied, the difference between the effective diameters of the two lens groups (LG1, LG2) can be reduced, and light loss can be suppressed. In addition, the optical system (1000) can improve chromatic aberration and control vignetting with respect to optical performance. Preferably, Formula 19 can satisfy: 0.7 <CA32 / CA41<1.2。

[0262] [Equation 20] 0.1 <CA52 / CA72<2

[0263] In Formula 20, when the effective diameter (CA52) of the tenth surface (S10) of the fifth lens (105) and the effective diameter (CA72) of the fourteenth surface (S14) of the seventh lens (107) are satisfied, the path of light traveling to the second lens group (LG2) can be set. In addition, the optical system (1000) can improve chromatic aberration. Preferably, Formula 20 can satisfy: 0.4 <CA52 / CA82<1。

[0264] [Formula 21]1 <CA92 / CA11<5

[0265] In Formula 21, when the effective diameter (CA91) of the eighteenth surface (S18) of the ninth lens (109) and the effective diameter (CA11) of the first surface (S1) of the first lens (101) are satisfied, the effective diameter and the optical path between the entrance lens and the last lens can be set. Therefore, the optical system (1000) can set the FOV and size of the optical system. Preferably, Formula 21 can satisfy: 2 <CA92 / CA11<3.5。

[0266] [Formula 21-1]5 <CA92 / CG8<15

[0267] In Equation 21-1, CA92 is the effective diameter of the largest lens surface and is the effective diameter of the eighteenth surface (S18) of the ninth lens (109). When the optical system (1000) according to the embodiment satisfies Equation 20-1, the optical system (1000) can improve the aberration characteristics and control the reduction of TTL. Preferably, Equation 21-1 can be satisfied: 8 < CA92 / CG8 < 13.

[0268] [Equation 21-2] 3 < CA82 / CG8 < 15

[0269] Equation 21-2 can set the effective diameter (CA82) of the sixteenth surface (S16) of the eighth lens (108) and the optical axis distance (CG8) between the eighth lens and the ninth lens (108, 109). When the optical system (1000) according to the embodiment satisfies Equation 21-2, the optical system (1000) can improve the aberration characteristics and control the reduction of TTL. Preferably, Equation 21-2 can be satisfied: 7 < CA82 / CG8 < 10.

[0270] [Equation 22] 0 < CG2 / (CT2 + CT3) < 1

[0271] In Equation 22, when the optical axis distance (CG2) between the second lens and the third lens (102, 103) and the sum of the center thicknesses of the second lens and the third lens (102, 103) are satisfied, the optical system (1000) can reduce chromatic aberration, improve the aberration characteristics, and control vignetting for optical performance. In addition, by designing the center distance between the second lens and the third lens (102, 103) to be less than the thickness of the adjacent lens, distortion aberration can be corrected. Preferably, Equation 22 can be satisfied: 0 < CG2 / (CT2 + CT3) < 0.5. The following condition can be satisfied: 9 < (CG2 / (CT2 + CT3)) * n < 3, where n is the total number of lenses.

[0272] [Equation 23] 0 < CG7 / (CT7 + CT8) < 1

[0273] In Equation 23, when the optical axis distance (CG7) between the seventh lens and the eighth lens (107, 108) and the sum of the center thicknesses of the adjacent lenses are satisfied, the optical system can have good optical performance at the center part of the FOV. In addition, by designing the edge distance between the seventh lens and the eighth lens (107, 108) to be less than the center thickness, distortion aberration can be compensated. Preferably, the following condition can be satisfied: 0 < CG7 / (CT7 + CT8) < 0.5.

[0274] [Equation 24] 0 < CG_Max / CG8 < 2

[0275] In Formula 24, CG_Max means the maximum distance among the center distances of the lens. When the optical system (1000) according to the embodiment satisfies Formula 24, the optical performance can be improved in the peripheral part of the FOV, and the distortion of the aberration characteristics can be suppressed. Preferably, in Formula 24, CG_Max and CG8 can be equal to each other.

[0276] [Equation 25] <CT7 / CG8<1

[0277] In Formula 25, when the center thickness (CT7) of the seventh lens (107) and the optical axis distance (CG8) between the eighth lens and the ninth lens (108, 109) are satisfied, the optical system (1000) can set the optical axis distance (CG8) between the eighth lens and the ninth lens and the center thickness of the seventh lens (107), and the optical performance of the peripheral part of the FOV can be improved. Preferably, Formula 25 can satisfy: <CT7 / CG8<0.7。

[0278] [Equation 26] <CG8 / CT8<3

[0279] In Formula 26, when the center thickness (CT8) of the eighth lens (108) and the optical axis distance (CG8) between the eighth lens and the ninth lens (108, 109) are satisfied, the optical system (1000) can reduce the effective diameter and distance of the eighth lens and the ninth lens, and can improve the optical performance of the peripheral portion of the FOV. Preferably, Formula 26 can satisfy: <CG8 / CT8<1。

[0280] [Equation 27] <CG8 / CT9<3

[0281] In Formula 27, when the center thickness (CT9) of the ninth lens (109) and the optical axis distance (CG8) between the eighth lens and the ninth lens (108, 109) are satisfied, the optical system (1000) can reduce the effective diameter of the ninth lens and the optical axis distance between the eighth lens and the ninth lens, and can improve the optical performance of the peripheral portion of the FOV. Preferably, Formula 27 can satisfy: 0.5 <CG8 / CT9<1。

[0282] [Equation 28] 200<|L5R2| / CT5

[0283] In Formula 27, when the radius of curvature (L5R2) of the tenth surface (S10) of the fifth lens (105) and the center thickness (CT5) of the fifth lens (105) are satisfied, the optical system (1000) can control the refractive power of the fifth lens (105) and can improve the optical performance of the light incident on the second lens group (LG2). Preferably, Formula 28 can satisfy: 250<|L5R2| / CT5.

[0284] [Equation 29] 0 < |L5R1| / L8R1 < 100

[0285] In Equation 29, when the radius of curvature (L5R1) of the ninth surface (S9) of the fifth lens (105) and the radius of curvature (L8R1) of the fifteenth surface (S15) of the eighth lens (108) 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 29 can satisfy: 30 < |L5R1| / L8R1 < 70. Preferably, the following conditions can be satisfied: L8R1 > 0.

[0286] [Equation 30] 0 < L1R1 / L1R2 < 1

[0287] Equation 30 can set the radii of curvature (L1R1, L1R2) of the first surface (S1) and the second surface (S2) on the object side of the first lens (101), and when these are satisfied, the lens size and resolution can be set. Preferably, Equation 30 can satisfy: 0 < L1R1 / L1R2 < 2. Preferably, it can satisfy: L1R1 > 0 and L1R2 > 0.

[0288] [Equation 31] 0 < |L2R2 / L2R1| < 20

[0289] Equation 31 can set the radii of curvature (L2R1, L2R2) of the third surface (S3) and the fourth surface (S4) on the object side of the second lens (102), and when these are satisfied, the resolution of the lens can be determined. Preferably, Equation 30 can satisfy: 5 < |L2R2 / L2R1| < 15. Preferably, it can satisfy: L2R1 > 0 and L2R2 < 0. At least one of Equation 29, 30, and 31 can include at least one of the following Equation 31-1 to 31-6, and the resolution of each lens can be determined.

[0290] [Equation 31-1] 0 < L3R1 / L3R2 < 10

[0291] Preferably, the following conditions can be satisfied: 1 < L3R1 / L3R2 < 5. L3R1, L3R2 > 0.

[0292] [Equation 31-2] 1 < L4R1 / L4R2 < 20.

[0293] [Equation 31-3] 1 < L5R1 / L5R2 < 2.

[0294] [Equation 31-4] 300 < |L6R1 / L6R2|

[0295] Preferably, the following conditions can be satisfied: 500 < |L6R1 / L6R2|.

[0296] [Formula 31-5]0 <L8R1 / L8R2<1.5

[0297] Preferably, 0 <L8R1 / L8R2<1。

[0298] [Formula 31-6]1 <L9R2 / L9R1<5

[0299] Preferably, 1.5 <L9R2 / L9R1<3。

[0300] By setting the center distance and edge distance between two adjacent lenses to the above range using equations 31, 31-1 to 31-6, the distortion aberration of the aberration characteristics can be corrected. The object side surface of the fourth lens (104) has a concave shape or a convex shape on the optical axis, and the absolute value of the radius of curvature can be greater than 100 mm, for example, 500 mm or greater.

[0301] [Equation 32] <CT_Max / CG_Max<2

[0302] In Formula 32, when the thickest thickness (CT_Max) among the center thicknesses of each of the lenses and the maximum value (CG_Max) of the air gap or distance on the optical axis between the plurality of lenses are satisfied, 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, and, for example, the TTL can be reduced. Preferably, Formula 32 can satisfy: 1 <CT_Max / CG_Max<1.5。

[0303] [Equation 33] 1<ΣCT / ΣCG<3

[0304] In Formula 33, ΣCT means the sum of the center thickness (unit: mm) of each of the plurality of lenses, and ΣCG means the sum of the distances (unit: mm) on the optical axis (OA) between two adjacent lenses of the plurality of lenses. When the optical system (1000) according to the embodiment satisfies Formula 33, 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, and, for example, TTL can be reduced. Preferably, Formula 33 can satisfy: 1.5<ΣCT / ΣCG<2.5. Therefore, the optical system can be designed so that the center thickness of each lens is reduced and the distance between adjacent lenses is increased.

[0305] [Equation 34] 10<∑Index<20

[0306] In Formula 34, ∑Index means 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 embodiment satisfies Formula 34, the TTL of the optical system (1000) can be controlled and improved resolution can be achieved. Here, the average value of the refractive index of the first lens to the ninth lens (101 to 109) can be 1.45 or greater, for example, in the range of 1.52 to 1.60. Preferably, Formula 34 can satisfy the condition: 12<∑Index<16 and 100<∑Index*n, where n is the total number of lenses.

[0307] [Equation 35] 10<∑Abbe / ∑Index<50

[0308] In Formula 35, ∑Abbe means the sum of the Abbe numbers of each of the plurality of lenses. When the optical system (1000) according to the embodiment satisfies Formula 35, the optical system (1000) may have improved aberration characteristics and resolution. The average value of the Abbe numbers of the first to ninth lenses (101 to 109) may be 43 or greater, for example, in the range of 43 to 47. Preferably, Formula 35 may satisfy: 20<∑Abbe / ∑Index<40. Preferably, the following condition may be satisfied: 360<(∑Abbe-∑Index).

[0309] [Equation 36] 25<ΣCT*n<35

[0310] In Formula 36, ​​when the relationship between the sum of all lens thicknesses and the number of each lens is satisfied, TTL can be reduced. Preferably, the following conditions can be satisfied: 10<ΣCG*n<20 and ΣCG<ΣCT.

[0311] [Equation 37] <ET_Max / CT_Max<3

[0312] In Formula 37, CT_Max means the thickest thickness (unit: mm) among the center thicknesses of each of the plurality of lenses, and ET_Max means the maximum edge thickness among the lenses, and the optical system (1000) according to the embodiment satisfies Formula 37. In this case, 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 37 can satisfy: 1 <ET_Max / CT_Max<1.5。

[0313] [Equation 38] 0.5 <CA11 / CA_Min<2

[0314] In Equation 38, when the effective diameter (CA11) of the first surface (S1) of the first lens (101) and the minimum effective diameter (CA_Min) of the lens surface are satisfied, the amount of light incident through the first lens (101) can be controlled, and a thin optical system can be provided while maintaining optical performance. Preferably, Equation 38 can satisfy: 1 < CA11 / CA_Min < 1.5.

[0315] [Equation 39] 1 < CA_Max / CA_Min < 5

[0316] In Equation 39, CA_Max means the maximum effective diameter among the object-side surface and the sensor-side surface of the plurality of lenses, and means the maximum effective diameter among the effective diameters (unit: mm) of the first surface to the eighteenth surface (S1 to S18). When the optical system (1000) according to the embodiment satisfies Equation 39, the optical system (1000) can provide a thin and compact optical system while maintaining optical performance. Preferably, Equation 39 can satisfy: 2 < CA_Max / CA_Min < 4.5. In addition, the following condition can be satisfied: 15 < (CA_Max / CA_Min) * n < 25.

[0317] [Equation 40] 1 < CA_Max / CA_AVR < 3

[0318] In Equation 40, 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 are satisfied, a thin and compact optical system can be provided. Preferably, Equation 40 can satisfy: 1.5 < CA_Max / CA_AVR < 2.5.

[0319] [Equation 41] 0.1 < CA_Min / CA_AVR < 1

[0320] In Equation 41, 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 these are satisfied, a thin and compact optical system can be provided. Preferably, Equation 41 can satisfy: 0.3 < CA_Min / CA_AVR < 0.9.

[0321] [Equation 42] 0.1 < CA_Max / (2*ImgH) < 1

[0322] In Formula 42, 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 is satisfied, the optical system (1000) has good optical performance in the center and peripheral parts of the FOV, and a slim and compact optical system can be provided. Here, ImgH can be in the range of 3 mm to 15 mm or 3 mm to 8 mm. Preferably, Formula 42 can satisfy: 0.5 <CA_Max / (2*ImgH)<1。

[0323] [Formula 43] <F / L8R2<5

[0324] In Formula 43, 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) may be set. When these are satisfied, the optical system (1000) may reduce the size of the optical system (1000), for example, reducing the total track length TTL. Preferably, Formula 43 may satisfy: <F / L8R2<1。

[0325] Formula 43 may also include the following Formula 43-1.

[0326] [Formula 43-1]2 <F / F#<8

[0327] F# may refer to the F number. Preferably, formula 43-1 may satisfy: 2 <F / F#<4。

[0328] [Formula 43-2]1 <F / L9R2<5

[0329] Formula 43-2 can set the total effective focal length (F) of the optical system (1000) and the radius of curvature (L9R2) of the eighteenth surface (S18) of the ninth lens (109). Preferably, Formula 43-2 can satisfy: <F / L9R2<4.5。

[0330] [Formula 44]1 <F / L1R1<10

[0331] In Formula 44, the radius of curvature (L1R1) of the first surface (S1) of the first lens (101) and the total effective focal length (F) may be set, and when these are satisfied, the optical system (1000) may be reduced in size, such as TTL. Preferably, Formula 44 may satisfy: <F / L1R1<5。

[0332] [Formula 45]0 <EPD / L9R2<10

[0333] In Equation 45, EPD means the entrance pupil diameter of the optical system (1000) (unit: mm), and L9R2 means the radius of curvature of the eighteenth surface (S18) of the ninth lens (109) (unit: mm). When the optical system (1000) according to the embodiment satisfies Equation 45, the optical system (1000) can control the overall brightness and has good optical performance in the center and peripheral portions of the FOV. Preferably, Equation 45 can be satisfied: 1 < EPD / L9R2 < 3. Equation 45 may further include the following Equation 45-1.

[0334] [Equation 45-1] 1 ≤ EPD / F# < 3

[0335] [Equation 46] 0 < EPD / L1R1 < 10

[0336] Equation 46 represents the relationship between the entrance pupil diameter of the optical system and the radius of curvature of the first surface (S1) of the first lens (101), and the incident light can be controlled. Preferably, Equation 46 can be satisfied: 0.5 < EPD / L1R1 < 1.

[0337] [Equation 47] 0 < F1 / F2 < 50

[0338] In Equation 47, the focal lengths (F1, F2) of the first lens and the second lens (101, 102) can be set. Therefore, the resolution can be improved by adjusting the refractive power of the incident light of the first lens and the second lens (101, 102), and the TTL can be controlled. Preferably, the following conditions can be satisfied: F1 > 0 and F2 > 0.

[0339] [Equation 48] 0 < F13 / F < 5

[0340] In Equation 48, when the combined focal length (F13) and the total focal length (F) of the first lens to the third lens are set, the optical system (1000) can improve the resolution by adjusting the refractive power of the incident light, and the TTL of the optical system (1000) can be controlled. Preferably, Equation 48 can be satisfied: 1 < F13 / F < 3.

[0341] [Equation 49] 0 < |F49 / F14| < 10

[0342] In Equation 49, the combined focal length (F13) of the first lens to the third lens - that is, the focal length of the first lens group (unit: mm) - and the combined focal length (F49) of the fourth lens to the ninth lens - that is, the focal length of the second lens group - can be set. When this is 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 provided in 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 satisfy: 3 < |F49 / F13| < 6. Here, the following conditions can be satisfied: F13 > 0 and F49 < 0.

[0343] [Equation 49-1] F13 + F2 < |F49|

[0344] 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 positive refractive power. When Equation 49-1 is satisfied, the optical system (1000) can improve aberration characteristics such as chromatic aberration and distortion aberration.

[0345] [Equation 50] 0 < F1 / F < 40

[0346] In Equation 50, the total focal length (F) and the focal length of the first lens (101) can be set, and the resolution can be improved. Equation 50 can satisfy: 10 < F1 / F < 20, and the following conditions can be satisfied: F1 > 0.

[0347] [Equation 50-1] 0 < F2 / F < 5 (here, F2 > 0)

[0348] [Equation 50-2] 0 < |F3 / F2| < 10 (where F3 < 0)

[0349] [Equation 50-3] 50 < |F4 / F| < 150 (where F4 < 0)

[0350] [Equation 50-4] 20 < |F5 / F| < 150 (where F5 > 0 or F5 < 0)

[0351] [Equation 50-5] 10 < |F6 / F| < 40 (where F6 > 0 or F6 < 0)

[0352] [Equation 50-6] 0 < |F7| / F < 3 (where F7 > 0 or F7 < 0)

[0353] [Equation 50-7] 0 < F8 / F < 10 (here, F8 > 0)

[0354] [Equation 50-8] 0 < |F9| / F < 2 (where F9 < 0)

[0355] [Equation 50-9] -0.5 < F9 / F1 < 0

[0356] In Equations 50-1 to 50-9, F3, F4, F5, F6, F7, F8, and F9 denote the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens (103, 104, 105, 106, 107, 108, 109), and the focal lengths (unit: mm). When this is satisfied, the resolution can be improved by controlling the refractive power of each lens, and an optical system can be provided in a thin and compact size. The focal lengths of each lens can be distributed to advantageously correct chromatic aberration.

[0357] [Equation 51] 5 < F1 / F13 < 40

[0358] By setting the focal length (F1) of the first lens and the combined focal length (F12) of the first lens to the third lens in Equation 51, the resolution of the first lens group can be adjusted. Preferably, the following condition can be satisfied: F13 < F1.

[0359] [Equation 52] 1 < |F1 / F49| < 10

[0360] In Equation 52, by setting the focal length (F1) of the first lens and the combined focal length (F49) of the fourth lens to the ninth lens, the size and resolution of the optical system can be adjusted. Preferably, it can satisfy: 0 > F49.

[0361] [Equation 53] 0 < |F1 / F4| < 1

[0362] In Equation 53, by setting the focal length (F1) of the first lens and the focal length (F4) of the fourth lens, 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| < 0.7, and F4 < 0.

[0363] [Equation 54] 2mm < TTL < 20mm

[0364] In Equation 54, TTL (total track length) denotes the distance (unit: mm) from the vertex of the first surface (S1) of the first lens (101) on the optical axis (OA) to the upper surface of the image sensor (300). Preferably, Equation 54 satisfies: 3 < TTL < 12 or TTL < 6.5, and thus a thin and compact optical system can be provided.

[0365] [Equation 55] 2mm < ImgH

[0366] Equation 55 sets the diagonal size (2*ImgH) of the image sensor (300) to be more than 4 mm, thus providing an optical system with high resolution. Equation 55 may preferably satisfy: 4≤ImgH≤15 or 4≤ImgH≤8.

[0367] Formula 55 may include at least one of the following Formulas 55-1 to 55-8.

[0368] [Equation 55-1] 0<∑CT / ImgH<1

[0369] [Equation 55-2]2<∑CG / ImgH<5

[0370] [Equation 55-3]2<∑Index / ImgH<5

[0371] [Formula 55-4] 70<∑Abbe / ImgH<110

[0372] [Equation 55-5](∑CT / n)>(∑CT / ImgH)

[0373] [Equation 55-6](∑CG / n)>(∑CG / ImgH)

[0374] [Equation 55-7](∑Index / n)>(∑Index / ImgH)

[0375] [Equation 55-8](∑Abbe / n)>(∑Abbe / ImgH)

[0376] Formulas 55-1 to 55-8 can establish the relationship between ImgH and the sum of the center thickness of all lenses, the sum of the center distances between lenses, the sum of the refractive indices 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 with an ImgH of 4 mm or 6 mm or more can be adjusted.

[0377] [Formula 56] BFL < 2.5 mm

[0378] Formula 56 can ensure the installation space of the filter (500) by making the back focal length (BFL) less than 2.5 mm, improve the assembly of components and improve the coupling reliability through the gap between the image sensor (300) and the last lens. Formula 56 can preferably satisfy: 0.8 <BFL<2。

[0379] [Formula 57]

[0380] 2mm <F<20mm

[0381] In equation 57, the total focal length (F) may be set to suit the optical system, and preferably, may satisfy: 4 <F<12。

[0382] [Equation 58] FOV < 120 degrees

[0383] In Equation 58, FOV (field of view) means the viewing angle (degrees) of the optical system (1000), and an optical system with a viewing angle of less than 120 degrees can be provided. The following conditions can be satisfied: FOV > 70, or FOV can be in the range of 70 degrees to 100 degrees.

[0384] [Equation 59] 0.1 < TTL / CA_Max < 2

[0385] In Equation 59, a thin and compact optical system can be provided by setting the maximum effective diameter (CA_Max) and TTL among the object side and the sensor side of multiple lenses. Preferably, Equation 59 can satisfy: 0.5 < TTL / CA_Max < 1.

[0386] [Equation 60] 0.5 < TTL / ImgH < 3

[0387] Equation 60 can set the total optical axis length (TTL) of the optical system and the diagonal length (ImgH) starting from the optical axis of the image sensor (300). When the optical system (1000) according to the embodiment satisfies Equation 60, the optical system (1000) can have a smaller back focal length (BFL) for applying a relatively large image sensor (300), such as a large image sensor (300) of about 1 inch, and thus can have a high-definition implementation and a thin structure. Preferably, Equation 60 can satisfy the conditions: 1 < TTL / ImgH < 2 or 0.5 < TTL / (2*ImgH) < 0.9. Preferably, the following conditions can be satisfied: ImgH < TTL and 20 < TTL*ImgH < 30.

[0388] [Equation 61] 0.01 < BFL / ImgH < 0.5

[0389] Equation 61 can set the optical axis distance between the image sensor (300) and the last lens and the diagonal length starting from the optical axis of the image sensor (300). When the optical system (1000) according to the embodiment satisfies Equation 61, the optical system (1000) can ensure the BFL for applying a relatively large image sensor (300), such as a large image sensor (300) of about 1 inch, and minimize the distance between the last lens and the image sensor (300), so as to have good optical characteristics at the central part and the peripheral part of the FOV. Preferably, Equation 61 can satisfy: 0.1 < BFL / ImgH < 0.4.

[0390] [Equation 62] 4 < TTL / BFL < 10

[0391] Formula 62 may set (unit: mm) the total optical axis length (TTL) of the optical system and the optical axis distance (BFL) between the image sensor (300) and the last lens. When the optical system (1000) according to the embodiment satisfies Formula 62, the optical system (1000) ensures the BFL and may be provided in a slim and compact manner. Formula 62 may satisfy: 4 <TTL / BFL<7。

[0392] [Equation 63] 0.5 <F / TTL<1.5

[0393] Formula 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. Formula 63 can preferably satisfy: 0.5 <F / TTL<1.2。

[0394] [Formula 63-1]0 <F# / TTL<0.5

[0395] Formula 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. Here, the following condition can be satisfied: F#<2.3, so the brightness can be controlled.

[0396] [Formula 64]3 <F / BFL<10

[0397] Formula 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 embodiment satisfies Formula 64, the optical system (1000) can have a set FOV and an appropriate focal length, and a slim and compact optical system can be provided. In addition, the optical system (1000) can minimize the gap between the last lens and the image sensor (300), and thus have good optical characteristics in the peripheral area of ​​the FOV. Preferably, Formula 64 can satisfy: 3 <F / BFL<7。

[0398] [Formula 65]0 <F / ImgH<3

[0399] Formula 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) such as about 1 inch, and can have improved aberration characteristics. Preferably, Formula 65 can satisfy: 0.8 <F / ImgH<1.5。

[0400] [Formula 66]1 <F / EPD<5

[0401] Equation 66 can set the total focal length (F) and the entrance pupil diameter (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.

[0402] [Equation 67] 0 < BFL / TD < 0.5

[0403] 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 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, since BFL is designed to be relatively large with respect to TD, the size of the entire optical system increases, making it difficult to miniaturize the optical system, and the unnecessary amount of light between the ninth lens and the image sensor may increase, resulting in problems such as a decrease in resolution due to deterioration of aberration characteristics.

[0404] [Equation 68] 0 < EPD / ImgH / FOV < 0.2

[0405] In Equation 68, the relationship between EPD, the length of half of the maximum diagonal length of the image sensor (ImgH), and FOV can be set. Therefore, the overall size and brightness of the optical system can be controlled. Equation 68 can preferably satisfy: 0 < EPD / ImgH / FOV < 0.01.

[0406] [Equation 69] 10 < FOV / F# < 55

[0407] Equation 69 can establish the relationship between the FOV and the F-number of the optical system. Equation 69 can preferably satisfy: 30 < FOV / F# < 40.

[0408] [Equation 70] 15 < (TD_LG2 / TD_LG1)*n < 30

[0409] Equation 70 can be set according to the total number of lenses for the optical axis distance (TD_LG1) of the first lens group and the optical axis distance (TD_LG2) of the second lens group.

[0410] [Equation 71] 5 < (CT_Max + CG_Max)*n < 20

[0411] Equation 71 can be set according to the number of lenses for the maximum center thickness of the lens and the maximum distance between adjacent lenses.

[0412] [Equation 72] 40 < (FOV*TTL) / n < 100

[0413] Equation 72 may be set for the FOV and total length of the optical system according to the number of lenses (n), and may preferably satisfy the following condition: 40<(FOV*TTL) / n<70.

[0414] [Equation 73] (TTL*n) <FOV

[0415] [Formula 74] 200 <CA_Max*TD*n<400

[0416] [Equation 75] 5<(TD / CA_Max)*n<15

[0417] In Formula 75, TD is the maximum optical axis distance (unit: 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 (101) to the eighteenth surface (S18) of the ninth lens (108) on the optical axis (OA). When the optical system (1000) according to the embodiment satisfies Formula 75, a slim and compact optical system can be provided. Preferably, the following conditions can be satisfied: 0.5 <TD / CA_Max<1.5。

[0418] [Formula 76] 15 < ((CA92 / CA41) / (CA11 / CA32))*n < 25

[0419] In Formula 76, the ratio of the effective diameter (CA41) of the object side surface of the second lens group to the effective diameter (CA91) of the sensor side surface and the ratio of the effective diameter (CA11) of the object side surface of the first lens group to the effective diameter (CA32) of the sensor side surface can be set according to the total number of lenses. According to Formulas 70 to 76, chromatic aberration, resolution, size, etc. of an optical system having ten or less lenses can be controlled.

[0420] [Formula 77]

[0421]

[0422] In Formula 77, Z is the sag and may refer to 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 cone constant. In addition, A, B, C, D, E, and F may refer to aspherical constants.

[0423] The optical system (1000) according to the embodiment may satisfy at least one or two or more of equations 1 to 76. In this case, the optical system (1000) may have improved optical characteristics. In detail, when the optical system (1000) satisfies at least one or two or more of equations 1 to 76, the optical system (1000) has improved resolution and can improve aberration and distortion characteristics. In addition, the optical system (1000) can ensure the BFL for applying a large-size image sensor 300, and can minimize the distance between the last lens and the image sensor (300), and thus has good optical performance in the central part and the peripheral part of the FOV. In addition, when the optical system (1000) satisfies at least one of equations 1 to 76, it can include a relatively large image sensor (300), have a relatively small TTL value, and can provide a thinner and more compact optical system and a camera module having the optical system.

[0424] Figure 3 , Figure 6 as well as Fig. 9 is an example of lens data of the optical system according to the first to third embodiments.

[0425] like Figure 3 , Figure 6 as well as Fig. 9 As shown in the figure, the optical system according to the first to third embodiments shows the radius of curvature on the optical axis (OA) of the first to ninth lenses (101 to 109), 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, the effective radius (semi-aperture) and the focal length.

[0426] The sum of the refractive indices of the plurality of lenses (100) is greater than 10, the Abbe sum is 300 or greater, for example, in the range of 300 to 450, and the sum of the center thicknesses of all the lenses is 4 mm or less, for example, in the range of 2 mm to 4 mm. The sum of the center distances between the first lens to the ninth lens on the optical axis is 3 mm or less, for example, in the range of 1 mm to 3 mm. The difference between the sum of the center thicknesses of the lenses and the sum of the center distances may be 1 mm or greater. In addition, the average value of the effective diameter of each lens surface of the plurality of lenses (100) is 5 mm or less, for example, in the range of 2 mm to 5 mm. The average center thickness of each lens may be 0.5 mm or less, for example, in the range of 0.2 mm to 0.5 mm. The sum of the effective diameters of each lens surface of the plurality of lenses (100) is the effective diameter of the first surface (S1) to the sixteenth surface (S16), and may be less than 100 mm, for example, in the range of 50 mm to 80 mm.

[0427] exist Figure 3 In the first embodiment, the lens having the maximum focal length is the fifth lens (105), the lens having the minimum focal length is the fourth lens (104), the lens surface having the maximum value among the curvature radii is the object side surface (L6S1) of the sixth lens (106), and the lens surface having the minimum value of the curvature radii is the object side surface (L4S1) of the fourth lens (104). Figure 6 In the second embodiment, the lens having the maximum focal length is the fifth lens (105), the lens having the minimum focal length is the fourth lens (104), the lens surface having the maximum value among the curvature radius is the object side surface (L4S1) of the fourth lens (104), and the lens surface having the minimum value of the curvature radius is the object side surface (L6S1) of the sixth lens (106). Fig. 9 In the third embodiment, the lens having the maximum focal length is the first lens, the lens having the minimum focal length is the fourth lens or the fifth lens, the lens surface having the maximum value among the radius of curvature is the object side surface (L4S1) of the fourth lens (104), and the lens surface having the minimum value among the radius of curvature is the object side surface (L6S1) of the sixth lens (106). In the first to third embodiments, when expressing absolute values, the lens having the maximum focal length is the fourth lens, and the lens surface having the maximum radius of curvature is the object side surface (L6S1) of the sixth lens (106).

[0428] like Figure 4 , Figure 7 as well as Fig.10 As shown in , at least one or all of the lens surfaces of the plurality of lenses in the embodiment may include an aspheric surface having a 30th order aspheric coefficient. For example, the first lens to the ninth lens (101 to 109) may include lens surfaces having a 30th order aspheric coefficient from the first surface (S1) to the eighteenth surface (S18). 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, and thus can well correct the optical performance of the peripheral area of ​​the FOV.

[0429] Table 1 shows the terms of the above-described formula in the optical system (1000) according to an embodiment, and relates to the TTL, BFL and F value as the total effective focal length, ImgH, the focal length of each of the first lens to the ninth lens (F1, F2, F3, F4, F5, F6, F7, F8, F9), the edge thickness, the edge distance, the composite focal length, etc. of the optical system (1000).

[0430] [Table 1]

[0431]

[0432]

[0433]

[0434] Table 2 shows Figure 1 Result values ​​of equations 1 to 42 described above 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 42. In detail, it can be seen that the optical system (1000) according to the embodiment satisfies all of the above equations 1 to 42. Therefore, the optical system (1000) can improve the optical performance and optical characteristics in the central part and the peripheral part of the FOV.

[0435] [Table 2]

[0436]

[0437]

[0438]

[0439]

[0440] Table 3 shows Figure 1 Result values ​​of equations 43 to 76 described above 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 more, or three or more of equations 43 to 76. In detail, it can be seen that the optical system (1000) according to the embodiment satisfies all of the above equations 1 to 76. Therefore, the optical system (1000) can improve the optical performance and optical characteristics in the central part and the peripheral part of the FOV.

[0441] [Table 3]

[0442]

[0443]

[0444]

[0445]

[0446] Fig.11 is a diagram showing that a camera module according to an embodiment is applied to a mobile terminal.

[0447] Reference Fig.11The mobile terminal (1) may include a camera module (10) disposed on the rear side. The camera module (10) may include an image capture function. In addition, the camera module (10) may include at least one of an auto focus function, a zoom function, and an OIS function.

[0448] The camera module (10) can process still images or video frames obtained by the image sensor (300) in a shooting 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 drawings, the camera module can also be provided on the front side of the mobile terminal (1).

[0449] For example, the camera module (10) may include a first camera module (10A) and a second camera module (10B). In this case, at least one of the first camera module (10A) and the second camera module (10B) may include the optical system (1000) described above. Therefore, the camera module (10) may have a slim structure and may have improved distortion and aberration characteristics. In addition, the camera module (10) may have good optical performance in the central part and the peripheral part of the FOV.

[0450] In addition, the mobile terminal (1) may further include an autofocus device (31). The autofocus device (31) may include an autofocus function using a laser. The autofocus device (31) may be mainly used in a situation where the autofocus function of an image using the camera module (10) is degraded, for example, in a proximity of 10 m or less or in a dark environment. The autofocus device (31) may include a light emitting unit including a vertical cavity surface emitting laser (VCSEL) semiconductor device and a light receiving unit such as a photodiode that converts light energy into electrical energy.

[0451] In addition, the mobile terminal (1) may further include a flash module (33). The flash module (33) may include a light emitting element that emits light therein. The flash module (33) may be operated by a camera operation of the mobile terminal or by a user's control.

[0452] 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 only one embodiment. In addition, the features, structures, and effects shown in each embodiment can be combined or modified by those skilled in the art in the field to which the embodiments belong with respect to other embodiments. Therefore, the contents related to these combinations and variations should be interpreted as being included within the scope of the present invention.

[0453] Although described based on the embodiment, this is only an example, the present invention is not limited, and it will be obvious to those skilled in the art that various modifications and applications not shown above are possible without departing from the essential features of the embodiment. For example, each component specifically shown in the embodiment can be modified and implemented. And the differences related to these modifications and applications should be interpreted as included in the scope of the present invention as defined in the appended claims.

Claims

1. An optical system, comprising: a first lens to a ninth lens arranged along an optical axis from an object side toward a sensor side; wherein the first lens has a positive refractive power on the optical axis and has a meniscus shape convex toward the object side; wherein the second lens has a positive refractive power on the optical axis and has a shape convex on both sides; wherein the ninth lens has a negative refractive power on the optical axis and has a meniscus shape convex toward the object side; wherein among the first lens to the ninth lens, the lens with the largest absolute value of focal length is the fourth lens; wherein among the first lens to the ninth lens, the lens surface with the largest absolute value of curvature radius is the object side surface of the sixth lens; wherein the focal length of the first lens is F1; wherein the focal length of the ninth lens is F9, and wherein the following formula is satisfied: -0.5 < F9 / F1 < 0.

2. The optical system according to claim 1, in, the optical axis distance from the center of the object side surface of the first lens to the upper surface of the image sensor is TTL; wherein half of the diagonal length of the image sensor is ImgH; wherein the following formula is satisfied: 0.5 < TTL / (2*ImgH) < 0.

9.

3. The optical system according to claim 1, in, the refractive index of the first lens is n1, and the Abbe number of the first lens is v1; wherein the refractive index of the third lens is n3, and the Abbe number of the third lens is v3; wherein the following formula is satisfied: (v3*n3) < (v1*n1).

4. The optical system according to claim 3, in, the following formula is satisfied: n1 < 1.6, wherein n1 < n3 and v1 > v3.

5. The optical system according to claim 3, in, the refractive index of the second lens is n2, and the Abbe number of the second lens is v2; wherein the following formula is satisfied: v3*n3 < v2*n2.

6. The optical system according to claim 3, in, the total focal length of the optical system is F; wherein the brightness of the optical system is F#; wherein the following formula is satisfied: 2 < F / F# < 4, wherein F# < 2.

3.

7. The optical system according to any one of claims 1 to 6, in, the sixth lens has a positive refractive power.

8. The optical system according to any one of claims 1 to 6, in, among the first lens to the ninth lens, the lens with the smallest effective diameter is the second lens, and among the first lens to the ninth lens, the lens with the largest effective diameter is the ninth lens.

9. The optical system according to any one of claims 1 to 6, in, the sensor side surface of the third lens has a concave shape; wherein the center distance between the third lens and the fourth lens is greater than the center distance between the second lens and the third lens, and greater than the center distance between the fourth lens and the fifth lens.

10. The optical system according to any one of claims 1 to 6, in, the object side surface of the fourth lens has a curvature radius of 500 mm or more on the optical axis.

11. An optical system comprising: a first lens having a meniscus shape convex toward the object side; a second lens disposed on a sensor side of the first lens; a third lens disposed on a sensor side of the second lens; a fourth lens disposed on the sensor side of the third lens; The nth lens, which is closest to the image sensor; an n-1th lens disposed on an object side of the nth lens; and two or more lenses disposed between the fourth lens and the n-1th lens, wherein the second lens has the smallest effective diameter among the lenses, 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 along an optical axis, The center distance between the third lens and the fourth lens is the maximum value among the center distances between the first lens to the fourth lens. wherein the radius of curvature of the object side surface of the fourth lens is L4R1, wherein the radius of curvature of the sensor-side surface of the fourth lens is L4R2, and Among them, the following formula is satisfied: 100<|L4R2|<|L4R1|.

12. The optical system according to claim 11, in, The sum of the center thicknesses of the first lens to the nth lens is ΣCT, The sum of the center distances between the first lens and the nth lens is ΣCG, and Among them, the following formula is satisfied: ΣCG<ΣCT.

13. The optical system according to claim 12, in, The total number of lenses is n, Among them, the following formula is satisfied: 5<(CT_Max+CG_Max)*n<20.

14. An optical system according to any one of claims 11 to 13, in, The number of lenses having a refractive index at the d-line of less than 1.6 among the lenses is 5 or more, and Among them, the number of lenses having an Abbe number greater than 45 among the lenses is 5 or more.

15. An optical system according to any one of claims 11 to 13, in, The sum of the refractive indices of the lens at the d-line is ΣIndex, Wherein, the sum of the Abbe numbers of the lenses is ∑Abbe, Among them, the following formula is satisfied: 10<∑Abbe / ∑Index<50.

16. The optical system according to claim 15, in, The optical axis distance from the center of the object side surface of the first lens to the upper surface of the image sensor is TTL, Wherein, 1 / 2 of the diagonal length of the image sensor is ImgH, Among them, the following formula is satisfied: 1 <TTL / ImgH<2。 17. 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, wherein 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 edge than the critical points of the object-side surface and the sensor-side surface of the n-1th lens.

18. An optical system comprising: The first lens group, which has a first lens to a third lens on the object side; The second lens group, which is disposed on the sensor side of the first lens group and has five or more lenses as compared with the number of lenses of the first lens group; And The aperture stop, which is disposed around the object side surface or the sensor side surface of the second lens, wherein the first lens group has a positive refractive power, wherein the second lens group has a negative refractive power, wherein the second lens has a convex object side surface and a convex sensor side surface on the optical axis, wherein the distance from the object side center of the first lens group to the optical axis of the image sensor is TTL, wherein the field of view of the optical system is FOV, wherein half of the diagonal length of the image sensor is ImgH, wherein n is the total number of lenses, wherein the following formula is satisfied: (TTL * n) < FOV wherein the following formula is satisfied: 0.5 < TTL / (2 * ImgH) < 0.

9.

19. An imaging device module, comprising: An image sensor, which is disposed on the sensor side of a plurality of lenses; And A filter, which is disposed between the last lens and the image sensor, wherein the optical system includes the optical system according to any one of claims 1, 11 or 18, wherein F is the total focal length, wherein TTL is the distance on the optical axis from the center of the object side surface of the lens closest to the object side to the upper surface of the image sensor, wherein ImgH is half of the maximum diagonal length of the image sensor, wherein the following formulas are satisfied: 0.5 < F / TTL < 1.5, and 1 < TTL / ImgH < 2.

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