Optical system and camera module including the same

Abstract

The optical system disclosed in the examples includes first to seventh lenses arranged sequentially along an optical axis from the object side to the image side, wherein the second lens has positive refractive power, the third lens has negative refractive power, the object side and image side surfaces of the second lens are convex, and the image side surface of the third lens is concave, and the first and third lenses can satisfy [Equation 1] 0.7<(SD L3S1) / (SD L1S1)<0.95 (in Equation 1, SD L1S1 means the effective radius of the object side surface of the first lens, and SD L3S1 means the effective radius of the object side surface of the third lens).

Description

Technical Field

[0001] The embodiments relate to an optical system for improved optical performance and a camera module including the same.

Background Art

[0002] A camera module functions to photograph an object and store it as an image or video, and is mounted on various applications. In particular, the camera module is manufactured in a ultra-small size and is applied not only to portable devices such as smartphones, tablet PCs, and notebook computers, but also to drones, vehicles, etc., providing various functions. For example, the optical system of the camera module may include an imaging lens that forms an image and an image sensor that converts the formed image into an electrical signal. At this time, the camera module can perform an autofocus (AF) function of automatically adjusting the distance between the image sensor and the imaging lens to align the focal length of the lens, and can perform a zooming function of zooming up or zooming out by increasing or decreasing the magnification of a distant object through a zoom lens. Also, the camera module employs an image stabilization (IS) technology to correct or prevent blurring of a video caused by movement of the camera due to an unstable fixing device or movement of the user. The most important element for such a camera module to obtain an image is the imaging lens that forms the image. Recently, interest in high resolution has been increasing, and research on an optical system including a plurality of lenses has been conducted to implement this. For example, research has been conducted using a plurality of imaging lenses having a positive (+) refractive power or a negative (-) refractive power to implement high resolution.

[0003] However, when multiple lenses are included, there is a problem in that it is difficult to derive excellent optical properties and aberration characteristics. In addition, when multiple lenses are included, the overall length and height increase due to the thickness, spacing, size, etc., of the multiple lenses, which in turn increases the overall size of the module containing the multiple lenses. Therefore, a new optical system that can solve the above problems is required. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The embodiment aims to provide an optical system with improved optical properties. The embodiment aims to provide an optical system that can reduce size. [Means for solving the problem]

[0005] The optical system according to an embodiment of the invention includes first to seventh lenses arranged sequentially along the optical axis from the object side to the image side, wherein the second lens has a positive refractive power, the third lens has a negative refractive power, the object side and image side of the second lens are convex, the image side of the third lens is concave, and the first and third lenses can satisfy the following formula 1.

[0006] [Formula 1] 0.7 < (SD L3S1) / (SD L1S1) < 0.95 (In Equation 1, SD L1S1 represents the effective radius of the object side of the first lens, and SD L3S1 represents the effective radius of the object side of the third lens.) According to embodiments of the invention, the first lens may have a negative refractive power and a meniscus shape that bulges toward the object.

[0007] According to embodiments of the invention, the sixth lens has a positive refractive power, and the object side surface of the sixth lens may be convex. The seventh lens has a negative refractive power, and the image side surface of the seventh lens may be concave.

[0008] According to embodiments of the invention, the sixth and seventh lenses can satisfy the following equation 2.

[0009] [Formula 2] 0.8 < (SD L6S2) / (SD L7S1) < 0.95 (In equation 2, SD L6S2 represents the effective radius of the image side of the sixth lens, and SD L7S1 represents the effective radius of the object side of the seventh lens.) According to embodiments of the invention, the third and fourth lenses can satisfy the following equation 3.

[0010] [Formula 3] 0.7 < (SD L3S2) / (SD L4S2) < 0.95 (In formula 3, SD L3S2 represents the effective radius of the image side of the third lens, and SD L4S2 represents the effective radius of the image side of the fourth lens.) An optical system according to an embodiment of the invention includes first to seventh lenses arranged sequentially along the optical axis from the object side to the image side, wherein the first lens has a negative refractive power, the second lens has a positive refractive power, and the third lens has a negative refractive power; the first lens has a meniscus shape that bulges toward the object side; the object side and image side of the second lens are convex; the first lens includes a first inflection point located on the image side, the first inflection point is located at a position that is 55% to 85% of the direction perpendicular to the optical axis, with the optical axis as the starting point and the end of the image side of the first lens as the ending point.

[0011] According to an embodiment of the invention, the sixth lens has a positive refractive power and can include a second inflection point located on the side of an object and a third inflection point located on the side of an image.

[0012] According to an embodiment of the invention, the second inflection point is positioned at 40% to 70% of the direction perpendicular to the optical axis, with the optical axis as the starting point and the end of the object side surface of the sixth lens as the ending point. The third inflection point is positioned at 35% to 65% of the direction perpendicular to the optical axis, with the optical axis as the starting point and the end of the image side surface of the sixth lens as the ending point.

[0013] According to an embodiment of the invention, the seventh lens has a negative refractive power and may include a fourth inflection point located on the side surface of an object. The fourth inflection point is located at a position of 5% to 25% with respect to a direction perpendicular to the optical axis, with the optical axis as the starting point and the end point being the end of the side surface of the seventh lens on the object. [Effects of the Invention]

[0014] The optical system and camera module according to the embodiment can have improved optical characteristics. Specifically, the optical system and camera module can satisfy at least one of several mathematical formulas, thereby blocking unnecessary light rays entering the optical system. As a result, the optical system and camera module can improve aberration characteristics.

[0015] Furthermore, the optical system according to the embodiment can have a slim structure. As a result, the device including the optical system, such as the camera module, can be provided in a slimmer and more compact form. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a diagram showing the configuration of the optical system according to the first embodiment. [Figure 2] Figure 2 is a graph illustrating the aberration characteristics of the optical system shown in Figure 1. [Figure 3] Figure 3 is a diagram showing the configuration of the optical system according to the second embodiment. [Figure 4] Figure 4 is a graph illustrating the aberration characteristics of the optical system shown in Figure 3. [Figure 5]FIG. 5 is a configuration diagram of an optical system according to the third embodiment. [Figure 6] FIG. 6 is a graph illustrating the aberration characteristics of the optical system of FIG. 5. [Figure 7] FIG. 7 is a drawing illustrating a state in which a camera module according to an embodiment is applied to a mobile terminal.

MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the technical idea of the present invention is not limited to a part of the embodiments described, and can be embodied in various forms. Within the scope of the technical idea of the present invention, components between embodiments can be selectively combined or replaced and used. Also, terms (including technical and scientific terms) used in the embodiments of the present invention are interpreted as meanings generally understood by those having ordinary knowledge in the technical field to which the present invention belongs, unless specifically described. Terms generally used like terms defined in a dictionary can be interpreted considering their meanings in the context of the relevant technology. The terms used in the embodiments of the present invention are for explaining the embodiments and are not intended to limit the present invention. In this specification, the singular form can include the plural form unless otherwise limited in the description, and when described as "at least one (or one or more) of A and B, C", it can include one or more of all combinations that can be combined with A, B, and C.

[0018] In the description of the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. can be used. Such terms are for distinguishing the components from other components, and the essence or order of the components is not limited by such terms. When a component is described as "connected", "coupled" or "connected" to another component, it includes both the case where the component is directly connected or connected to the other component and the case where another component is further "connected", "coupled" or "connected" between the components. When it is described that it is formed or arranged "above or below" each component, "above or below" includes not only the case where two components are in direct contact, but also the case where one or more other components are formed or arranged between the two components. Also, when expressed as "above or below", it can include the meaning not only in the upward direction but also in the downward direction with respect to one component as a reference.

[0019] That the surface of the lens is convex means that the surface of the lens in the region corresponding to the optical axis has a convex shape, and that the surface of the lens is concave can mean that the surface of the lens in the region corresponding to the optical axis has a concave shape. "Object side surface" can mean the surface of the lens facing the object side with respect to the optical axis, and "image side surface" can mean the surface of the lens facing the imaging surface with respect to the optical axis. The vertical direction means the direction perpendicular to the optical axis, and the end of the lens or the surface of the lens can mean the outermost end of the effective region of the lens through which the incident light passes.

[0020] The optical system 1000 according to the embodiment may include a plurality of lenses 100. For example, the optical system 1000 according to the embodiment may include five or more lenses. More specifically, the optical system 1000 may include seven lenses. That is, the optical system 1000 may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a seventh lens 170, and an image sensor 300, which are arranged sequentially from the object side to the image side. The first to seventh lenses 110, 120, 130, 140, 150, 160, and 170 are arranged sequentially along the optical axis OA of the optical system 1000.

[0021] Light corresponding to information about an object can pass through the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160, and the seventh lens 170 and be incident on the image sensor 300. Each of the plurality of lenses 100 may include an effective region and an ineffective region. The effective region is the region through which light incident on each of the first to seventh lenses 110, 120, 130, 140, 150, 160, and 170 passes. That is, the effective region is the region in which the incident light is refracted and exhibits optical properties. The ineffective region is arranged around the effective region. The ineffective region is the region in which the light is not incident. That is, the ineffective region is the region unrelated to the optical properties. The ineffective region may also be a region fixed to a barrel (not shown) or the like that houses the lenses.

[0022] The image sensor 300 is capable of sensing light. More specifically, the image sensor 300 is capable of sensing light that has passed sequentially through the plurality of lenses 100, more specifically the first to seventh lenses 110, 120, 130, 140, 150, 160, and 170. The image sensor 300 may include a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), etc. The optical system 1000 according to the embodiment may further include a filter 500. The filter 500 is positioned between the plurality of lenses 100 and the image sensor 300. The filter 500 is positioned between the last lens (seventh lens 170) of the plurality of lenses 100 that is closest to the image sensor 300 and the image sensor 300. The filter 500 may include at least one of optical filters such as an infrared filter or a cover glass. The filter 500 can allow light in a set wavelength band to pass through and filter out light in a different wavelength band. If the filter 500 includes an infrared filter, it can block the transmission of radiant heat emitted from external light to the image sensor 300. Furthermore, the filter 500 can transmit visible light and reflect infrared light.

[0023] Furthermore, the optical system 1000 according to the embodiment may include an aperture (not shown). The aperture can adjust the amount of light incident on the optical system 1000. The aperture is located in front of the first lens 110 or positioned between two lenses selected from the first to seventh lenses 110, 120, 130, 140, 150, 160, and 170. For example, the aperture is positioned between the first lens 110 and the second lens 120. Also, at least one of the first to seventh lenses 110, 120, 130, 140, 150, 160, and 170 can act as an aperture. For example, the object side or image side of one lens selected from the first to seventh lenses 110, 120, 130, 140, 150, 160, and 170 can act as an aperture to adjust the amount of light. For example, the object side (third surface S3) of the second lens 120 can act as an aperture.

[0024] The optical system 1000 according to the embodiment may further include an optical path changing member (not shown). The optical path changing member can change the path of light by reflecting light incident from the outside. The optical path changing member may include a reflector or a prism. For example, the optical path changing member may include a right-angle prism. If the optical path changing member includes a right-angle prism, the optical path changing member can change the path of light by reflecting the path of incident light at a 90-degree angle. The optical path changing member is positioned adjacent to the object side of the first to seventh lenses 110, 120, 130, 140, 150, 160, and 170. That is, when the optical system 1000 includes the optical path changing member, the optical path changing member, the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160, the seventh lens 170, the filter 500, and the image sensor 300 are arranged in that order from the object side to the image side. The optical path changing member can reflect light incident from the outside and change the path of the light in a set direction. The optical path changing member can reflect light incident on the optical path changing member and change the path of the light in the direction of the first to seventh lenses 110, 120, 130, 140, 150, 160, and 170. When the optical system 1000 includes the optical path changing member, the optical system can be applied to a foldable camera that can reduce the thickness of the camera. More specifically, if the optical system 1000 includes the optical path changing member, it can change light incident perpendicular to the surface of the applied device to a direction parallel to the surface of the device. This allows the optical system 1000, including multiple lenses, to have a thinner thickness within the device, thus providing a thinner device. More specifically, if the optical system 1000 does not include the optical path changing member, the multiple lenses within the device are arranged to extend perpendicular to the surface of the device. This causes the optical system 1000, including multiple lenses, to have a greater height perpendicular to the surface of the device, making it difficult to form a thin device.However, if the optical system 1000 includes the optical path changing member, it can be applied to a folded camera, and the plurality of lenses are arranged to extend in a direction parallel to the surface of the device. That is, the optical system 1000 is arranged such that the optical axis OA is parallel to the surface of the device. As a result, the optical system 1000 including the plurality of lenses can have a low height in the direction perpendicular to the surface of the device. Therefore, the folded camera including the optical system 1000 can have a thin thickness within the device, and the thickness of the device can also be reduced.

[0025] Below, we will provide a more detailed explanation of several lenses (100).

[0026] The first lens 110 may have a positive (+) or negative (-) refractive power. The first lens 110 may be made of plastic or glass material. For example, the first lens 110 may be made of plastic material. The first lens 110 may include a first surface S1 defined as an object side surface and a second surface S2 defined as an image side surface. The first surface S1 may be convex, and the second surface S2 may be concave. That is, the first lens 110 may have a meniscus shape that bulges towards the object side. Hereinafter, the image side or image side surface may be the sensor side or sensor side surface. At least one of the first surface S1 and the second surface S2 may be aspherical. For example, the first surface S1 and the second surface S2 may both be aspherical.

[0027] The first lens 110 may include at least one inflection point. More specifically, at least one of the first surface S1 and the second surface S2 may include an inflection point. For example, the second surface S2 may include a first inflection point defined by an inflection point. The first inflection point is located at a position of approximately 85% or less when the optical axis OA is the starting point and the end of the second surface S2 of the first lens 110 is the ending point. More specifically, the first inflection point is located at a position of approximately 55% to approximately 85% when the optical axis OA is the starting point and the end of the second surface S2 of the first lens 110 is the ending point. More specifically, the first inflection point is located at a position of approximately 60% to approximately 80% when the optical axis OA is the starting point and the end of the second surface S2 of the first lens 110 is the ending point. Here, the end of the second surface S2 can mean the final end of the effective area of ​​the second surface S2 of the first lens 110, and the position of the first inflection point may be a position set with reference to a direction perpendicular to the optical axis OA.

[0028] The second lens 120 may have a positive refractive power. The second lens 120 may be made of plastic or glass material. For example, the second lens 120 may be made of plastic material. The second lens 120 may include a third surface S3 defined as an object side surface and a fourth surface S4 defined as an image side surface. The third surface S3 may be convex, and the fourth surface S4 may be convex. That is, both surfaces of the second lens 120 may be convex. At least one of the third surface S3 and the fourth surface S4 may be aspherical. For example, both the third surface S3 and the fourth surface S4 may be aspherical.

[0029] The third lens 130 may have a negative refractive power. The third lens 130 may be made of plastic or glass material. For example, the third lens 130 may be made of plastic material. The third lens 130 may include a fifth surface S5 defined as the object side and a sixth surface S6 defined as the image side. The fifth surface S5 may be convex, and the sixth surface S6 may be concave. That is, the third lens 130 may have a meniscus shape that bulges towards the object side. Conversely, the fifth surface S5 may be concave, and the sixth surface S6 may be concave. That is, both surfaces of the third lens 130 may be concave. At least one of the fifth surface S5 and the sixth surface S6 may be aspherical. For example, both the fifth surface S5 and the sixth surface S6 may be aspherical.

[0030] The fourth lens 140 may have a positive (+) or negative (-) refractive power. The fourth lens 140 may be made of plastic or glass material. For example, the fourth lens 140 may be made of plastic material. The fourth lens 140 may include a seventh surface S7 defined as the object side and an eighth surface S8 defined as the image side. The seventh surface S7 may be convex, and the eighth surface S8 may be concave. That is, the fourth lens 140 may have a meniscus shape that bulges towards the object side. Conversely, the seventh surface S7 may be convex, and the eighth surface S8 may be convex. That is, both surfaces of the fourth lens 140 may be convex. Conversely, the seventh surface S7 may be concave, and the eighth surface S8 may be concave. That is, both surfaces of the fourth lens 140 may be concave. In contrast, the seventh surface S7 may be concave, and the eighth surface S8 may be convex. That is, the fourth lens 140 may have a meniscus shape that bulges towards the image side. At least one of the seventh surface S7 and the eighth surface S8 may be aspherical. For example, both the seventh surface S7 and the eighth surface S8 may be aspherical.

[0031] The fifth lens 150 may have a positive (+) or negative (-) refractive power. The fifth lens 150 may be made of plastic or glass material. For example, the fifth lens 150 may be made of plastic material. The fifth lens 150 may include a ninth surface S9 defined as an object side surface and a tenth surface S10 defined as an image side surface. The ninth surface S9 may be concave, and the tenth surface S10 may be convex. That is, the fifth lens 150 may have a meniscus shape that bulges towards the image side. At least one of the ninth surface S9 and the tenth surface S10 may be aspherical. For example, both the ninth surface S9 and the tenth surface S10 may be aspherical.

[0032] The sixth lens 160 may have a positive refractive power. The sixth lens 160 may be made of plastic or glass material. For example, the sixth lens 160 may be made of plastic material. The sixth lens 160 may include an eleventh surface S11 defined as an object side surface and a twelfth surface S12 defined as an image side surface. The eleventh surface S11 may be convex, and the twelfth surface S12 may be concave. That is, the sixth lens 160 may have a meniscus shape that bulges towards the object side. At least one of the eleventh surface S11 and the twelfth surface S12 may be aspherical. For example, the eleventh surface S11 and the twelfth surface S12 may both be aspherical. The sixth lens 160 may include at least one inflection point. More specifically, at least one of the eleventh surface S11 and the twelfth surface S12 may include an inflection point. As an example, the 11th surface S11 may include a second inflection point defined as an inflection point. The second inflection point is located at a position of approximately 70% or less when the optical axis OA is the starting point and the end of the 11th surface S11 of the 6th lens 160 is the ending point. More specifically, the second inflection point is located at a position of approximately 40% to approximately 70% when the optical axis OA is the starting point and the end of the 11th surface S11 of the 6th lens 160 is the ending point. More specifically, the second inflection point is located at a position of approximately 45% to approximately 65% ​​when the optical axis OA is the starting point and the end of the 11th surface S11 of the 6th lens 160 is the ending point. Here, the end of the 11th surface S11 can mean the final end of the effective area of ​​the 11th surface S11 of the 6th lens 160, and the position of the second inflection point may be set with reference to a direction perpendicular to the optical axis OA. The 12th surface S12 may include a third inflection point defined as an inflection point. The third inflection point is located at a position of approximately 65% ​​or less when the optical axis OA is the starting point and the end of the 12th surface S12 of the 6th lens 160 is the ending point. More specifically, the third inflection point is located at a position of approximately 35% to approximately 65% ​​when the optical axis OA is the starting point and the end of the 12th surface S12 of the 6th lens 160 is the ending point.More specifically, the third inflection point is positioned at approximately 40% to 60% of the distance between the optical axis OA (start point) and the end of the twelfth surface S12 of the sixth lens 160 (end point). Here, the end of the twelfth surface S12 can mean the final end of the effective area of ​​the twelfth surface S12 of the sixth lens 160, and the position of the third inflection point may be set with reference to a direction perpendicular to the optical axis OA.

[0033] The seventh lens 170 may have a negative refractive power. The seventh lens 170 may be made of plastic or glass material. For example, the seventh lens 170 may be made of plastic material. The seventh lens 170 may include a thirteenth surface S13 defined as an object side surface and a fourteenth surface S14 defined as an image side surface. The thirteenth surface S13 may be convex, and the fourteenth surface S14 may be concave. That is, the seventh lens 170 may have a meniscus shape that bulges towards the object side. Conversely, the thirteenth surface S13 may be concave, and the fourteenth surface S14 may be concave. That is, both surfaces of the seventh lens 170 may be concave. At least one of the thirteenth surface S13 and the fourteenth surface S14 may be aspherical. For example, both the thirteenth surface S13 and the fourteenth surface S14 may be aspherical. The seventh lens 170 may include at least one inflection point. More specifically, at least one of the thirteenth surface S13 and the fourteenth surface S14 may include an inflection point. For example, the thirteenth surface S13 may include a fourth inflection point defined by an inflection point. The fourth inflection point is located at a position of approximately 30% or less when the optical axis OA is the starting point and the end of the thirteenth surface S13 of the seventh lens 170 is the ending point. More specifically, the fourth inflection point is located at a position of approximately 25% or less when the optical axis OA is the starting point and the end of the thirteenth surface S13 of the seventh lens 170 is the ending point. More specifically, the fourth inflection point is located at a position of approximately 5% to approximately 25% when the optical axis OA is the starting point and the end of the thirteenth surface S13 of the seventh lens 170 is the ending point. Here, the end of the 13th surface S13 can mean the final end of the effective area of ​​the 13th surface S13 of the 7th lens 170, and the position of the 4th inflection point may be a position set with reference to a direction perpendicular to the optical axis OA. The 14th surface S14 may include a 5th inflection point defined by the inflection point. The 5th inflection point is located at a position of approximately 45% or less when the optical axis OA is the starting point and the end of the 14th surface S14 of the 7th lens 170 is the ending point.More specifically, the fifth inflection point is located at a position approximately 15% to 45% when the optical axis OA is the starting point and the end of the 14th surface S14 of the 7th lens 170 is the ending point. More specifically, the fifth inflection point is located at a position approximately 20% to 40% when the optical axis OA is the starting point and the end of the 14th surface S14 of the 7th lens 170 is the ending point. Here, the end of the 14th surface S14 can mean the final end of the effective area of ​​the 14th surface S14 of the 7th lens 170, and the position of the fifth inflection point may be set with reference to a direction perpendicular to the optical axis OA.

[0034] The optical system 1000 according to the embodiment can satisfy at least one of the following mathematical formulas. As a result, the optical system 1000 according to the embodiment can have improved optical effects. Furthermore, the optical system 1000 according to the embodiment can have a slimmer structure.

[0035] [Formula 1] 0.7 < (SD L3S1) / (SD L1S1) < 0.95 In Equation 1, SD L1S1 represents the semi-aperture of the object side surface (first surface S1) of the first lens 110, and SD L3S1 represents the semi-aperture of the object side surface (third surface S3) of the third lens 130.

[0036] [Formula 2] 0.8 < (SD L6S2) / (SD L7S1) < 0.95 In equation 2, SD L6S2 represents the semi-aperture of the image side (12th surface S12) of the sixth lens 160, and SD L7S1 represents the semi-aperture of the object side (13th surface S13) of the seventh lens 170.

[0037] [Formula 3] 0.7 < (SD L3S2) / (SD L4S2) < 0.95 In equation 3, SD L3S2 represents the semi-aperture of the image side (sixth surface S6) of the third lens 130, and SD L4S2 represents the semi-aperture of the image side (eighth surface S8) of the fourth lens 140.

[0038] [Equation 4] 0.45 < (L1_CT) / (L2_CT) < 0.75 In equation 4, L1_CT represents the central thickness of the first lens 110, and L2_CT represents the central thickness of the second lens 120.

[0039] [Formula 5] 1.5 < (L2_CT) / (L3_CT) < 4 In equation 5, L2_CT represents the central thickness of the second lens 120, and L3_CT represents the central thickness of the third lens 130.

[0040] [Formula 6] 10 < |f1| / |f2| < 100 In equation 6, f1 represents the focal length of the first lens 110, and f2 represents the focal length of the second lens 120.

[0041] [Equation 7] 0.5 < |f2 / f6| < 1.5 In equation 7, f2 represents the focal length of the second lens 120, and f6 represents the focal length of the sixth lens 160.

[0042] [Equation 8] 0.5 <f2 / F<1.5 In equation 8, f2 represents the focal length of the second lens 120, and F represents the effective focal length of the optical system 1000.

[0043] [Formula 9] 6 <f1 / f7<22 In equation 9, f1 represents the focal length of the first lens 110, and f7 represents the focal length of the seventh lens 170.

[0044] [Formula 10] -0.8 <f6 / f7<-0.3 In equation 10, f6 represents the focal length of the sixth lens 160, and f7 represents the focal length of the seventh lens 170.

[0045] [Equation 11] -40 <f1 / F<-10 In equation 11, f1 represents the focal length of the first lens 110, and F represents the effective focal length of the optical system 1000.

[0046] [Formula 12] 1 < (L1_CT) / (L3_CT) < 1.9 In formula 12, L1_CT represents the central thickness of the first lens 110, and L3_CT represents the central thickness of the third lens 130.

[0047] [Formula 13] 1.1 < (L6_CT) / (L7_CT) < 1.7 In formula 13, L6_CT represents the central thickness of the sixth lens 160, and L7_CT represents the central thickness of the seventh lens 170.

[0048] [Formula 14] 0.6 < (L3_CT) / (L4_CT) < 1 In formula 14, L3_CT represents the central thickness of the third lens 130, and L4_CT represents the central thickness of the fourth lens 140.

[0049] [Formula 15] n2d<1.6 In equation 15, n2d represents the refractive index of the second lens 120. More specifically, n2d represents the refractive index at the d-line.

[0050] [Formula 16] V3d<30 In equation 16, V3d represents the Abbe number of the third lens 130.

[0051] [Formula 17] 1.4 <F / EPD<2 In equation 17, F represents the effective focal length of the optical system 1000, and EPD represents the diameter of the entrance pupil (entrance pupil size) of the optical system 1000.

[0052] [Formula 18] -0.18 <L1R1 / L2R2<-0.1 In equation 18, L1R1 represents the radius of curvature of the object side surface (first surface S1) of the first lens 110, and L2R2 represents the radius of curvature of the image side surface (fourth surface S4) of the second lens 120.

[0053] [Formula 19] 1 <L1R2 / L2R1<1.15 In equation 19, L1R2 represents the radius of curvature of the image side (second surface S2) of the first lens 110, and L2R1 represents the radius of curvature of the object side (third surface S3) of the second lens 120.

[0054] [Formula 20] 1.05 <L6R1 / L7R2<1.55 In equation 20, L6R1 represents the radius of curvature of the object side surface (11th surface S11) of the sixth lens 160, and L7R2 represents the radius of curvature of the image side surface (14th surface S14) of the seventh lens 170.

[0055] [Formula 21] 3 <L6R2 / L7R2<3.8 In equation 21, L6R2 represents the radius of curvature of the image surface (12th surface S12) of the sixth lens 160, and L7R2 represents the radius of curvature of the image surface (14th surface S14) of the seventh lens 170.

[0056] [Formula 22] 0.5 <TTL / ImgH<0.9 In equation 22, TTL (Total track length) means the distance in the direction of the optical axis OA from the vertex of the object side surface (first surface S1) of the first lens 110 to the upper surface of the image sensor 300, and ImgH means the distance in the direction perpendicular to the optical axis OA from the 0 field region at the center of the upper surface of the image sensor 300 that coincides with the optical axis OA to the 1.0 field region of the image sensor 300. That is, ImgH means half the diagonal length of the effective area of ​​the image sensor 300.

[0057] [Formula 23] 0.05 <BFL / ImgH<0.2 In equation 23, BFL (Back focal length) means the distance in the direction of the optical axis OA from the vertex of the image side surface (14th surface S14) of the 7th lens 170 to the upper surface of the image sensor 300, and ImgH means the distance in the direction perpendicular to the optical axis OA from the 0 field region at the center of the upper surface of the image sensor 300 that coincides with the optical axis OA to the 1.0 field region of the image sensor 300. That is, ImgH means half the diagonal length of the effective area of ​​the image sensor 300.

[0058] [Formula 24] 4 <TTL / BFL<7 In equation 24, TTL (Total track length) means the distance in the optical axis direction OA from the vertex of the object side surface (first surface S1) of the first lens 110 to the upper surface of the image sensor 300, and BFL (Back focal length) means the distance in the optical axis direction OA from the vertex of the image side surface (14th surface S14) of the seventh lens 170 to the upper surface of the image sensor 300.

[0059] [Formula 25] 0.6 <F / TTL<0.95 In equation 25, F represents the effective focal length of the optical system 1000, and TTL represents the distance in the optical axis direction OA from the vertex of the object side surface (first surface S1) of the first lens 110 to the upper surface of the image sensor 300.

[0060] [Formula 26] |f1|>|f2|+|f3|+|f4|+|f5|+|f6|+|f7| In equation 26, f1 to f7 represent the respective focal lengths of the first to seventh lenses 110, 120, 130, 140, 150, 160, and 170.

[0061] [Formula 27] In formula 27 of TIFF0007837978000001.tif18138, Z can be expressed as Sag and represent the distance in the optical axis direction from any position on the aspherical surface to the vertex of the aspherical surface.

[0062] Furthermore, Y can represent the distance from any point on the aspherical surface to the optical axis in a direction perpendicular to the optical axis.

[0063] Furthermore, c can represent the curvature of the lens, and K can represent the conic constant.

[0064] Furthermore, A, B, C, D, E, and F can represent aspheric constants.

[0065] The optical system 1000 according to the embodiment can satisfy at least one of the equations 1 to 26. In this case, the optical system 1000 can have improved optical characteristics. Specifically, the optical system 1000 can improve aberration characteristics by blocking unnecessary light rays entering the optical system 1000. Furthermore, if the optical system 1000 satisfies at least one of the equations 1 to 26, the optical system 1000 can have a slimmer structure, thereby providing a slimmer and more compact apparatus including the optical system 1000.

[0066] The optical system 1000 according to the first embodiment will be described in more detail with reference to Figures 1 and 2. Figure 1 is a diagram of the configuration of the optical system according to the first embodiment, and Figure 2 is a graph illustrating the aberration characteristics of the optical system according to the first embodiment.

[0067] Referring to Figures 1 and 2, the optical system 1000 according to the first embodiment may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a seventh lens 170, and an image sensor 300, which are arranged sequentially from the object side to the image side. The first to seventh lenses 110, 120, 130, 140, 150, 160, and 170 are arranged sequentially along the optical axis OA of the optical system 1000.

[0068] Furthermore, in the optical system 1000 according to the first embodiment, the third surface S3 of the second lens 120 can function as an aperture. In addition, a filter 500 is placed between the multiple lenses 100 and the image sensor 300. Specifically, the filter 500 is placed between the seventh lens 170 and the image sensor 300. [Table 1] Table 1 shows the radius of curvature, thickness, distance between the lenses, refractive index, Abbe's number, and semi-aperture of the first to seventh lenses 110, 120, 130, 140, 150, 160, and 170 according to the first embodiment. Referring to Figures 1 and 2 and Table 1, the first lens 110 of the optical system 1000 according to the first embodiment can have a negative refractive power. The first surface S1 of the first lens 110 can be convex, and the second surface S2 can be concave. The first lens 110 can have a meniscus shape that bulges towards the object. The first surface S1 may be aspherical, and the second surface S2 may be aspherical. The second lens 120 can have a positive refractive power. The third surface S3 of the second lens 120 may be convex, and the fourth surface S4 may be convex. Both surfaces of the second lens 120 may be convex. The third surface S3 may be aspherical, and the fourth surface S4 may be aspherical. The third lens 130 may have a negative refractive power. The fifth surface S5 of the third lens 130 may be convex, and the sixth surface S6 may be concave. The third lens 130 may have a meniscus shape that bulges towards the object. The fifth surface S5 may be aspherical, and the sixth surface S6 may be aspherical.

[0069] The fourth lens 140 can have a positive (+) refractive power. The seventh surface S7 of the fourth lens 140 can be convex, and the eighth surface S8 can be convex. Both surfaces of the fourth lens 140 can be convex. The seventh surface S7 may be aspherical, and the eighth surface S8 may be aspherical. The fifth lens 150 can have a negative (-) refractive power. The ninth surface S9 of the fifth lens 150 can be concave, and the tenth surface S10 may be concave. Both surfaces of the fifth lens 150 can be concave. The ninth surface S9 may be aspherical, and the tenth surface S10 may be aspherical. The sixth lens 160 can have a positive (+) refractive power. The eleventh surface S11 of the sixth lens 160 can be convex, and the twelfth surface S12 can be concave. The sixth lens 160 may have a meniscus shape that bulges toward the object. The eleventh surface S11 may be aspherical, and the twelfth surface S12 may be aspherical. The seventh lens 170 may have a negative refractive power. The thirteenth surface S13 of the seventh lens 170 may be convex, and the fourteenth surface S14 may be concave. The seventh lens 170 may have a meniscus shape that bulges toward the object. The thirteenth surface S13 may be aspherical, and the fourteenth surface S14 may be aspherical.

[0070] In the optical system 1000 according to the first embodiment, the values ​​of the aspheric coefficients for each lens surface are as shown in Table 2 below. [Table 2] [Table 3] [Table 4] Table 3 shows the TTL (Total track length), BFL (Back focal length), F-number, ImgH, the focal lengths f1, f2, f3, f4, f5, f6, f7 of the first to seventh lenses 110, 120, 130, 140, 150, and 160 respectively, and the entrance pupil size (EPD), etc., for the optical system 1000 according to the first embodiment, corresponding to the items in the formulas described above. Table 4 shows the result values ​​for formulas 1 to 26 described above for the optical system 1000 according to the first embodiment. Referring to Table 4, it can be seen that the optical system 1000 according to the first embodiment satisfies at least one of formulas 1 to 26. In more detail, it can be seen that the optical system 1000 according to the first embodiment satisfies all of formulas 1 to 26.

[0071] As a result, the optical system 1000 according to the first embodiment is provided with a slimmer structure. Furthermore, the optical system 1000 has improved optical characteristics and can have aberration characteristics as shown in Figure 2. Specifically, Figure 2 is a graph of the aberration characteristics of the optical system 1000 according to the first embodiment, showing spherical aberration (Longitudinal Spherical Aberration), astigmatic field curves, and distortion measured from left to right. In Figure 2, the X axis can represent focal length (mm) and distortion (%), and the Y axis can represent image height. The graph for spherical aberration is for light in the wavelength bands of approximately 470 nm, 510 nm, 555 nm, 610 nm, and 650 nm, while the graphs for astigmatic aberration and distortion are for light in the wavelength band of 555 nm.

[0072] The optical system 1000 according to the second embodiment will be described in more detail with reference to Figures 3 and 4. Figure 3 is a configuration diagram of the optical system according to the second embodiment, and Figure 4 is a graph illustrating the aberration characteristics of the optical system according to the second embodiment.

[0073] Referring to Figures 3 and 4, the optical system 1000 according to the second embodiment may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a seventh lens 170, and an image sensor 300, which are arranged sequentially from the object side to the image side. The first to seventh lenses 110, 120, 130, 140, 150, 160, and 170 are arranged sequentially along the optical axis OA of the optical system 1000.

[0074] In the optical system 1000 according to the second embodiment, the third surface S3 of the second lens 120 can function as an aperture. Furthermore, a filter 500 is placed between the multiple lenses 100 and the image sensor 300. Specifically, the filter 500 is placed between the seventh lens 170 and the image sensor 300. [Table 5] Table 5 shows the radius of curvature, thickness, distance between the lenses, refractive index, Abbe's number, and semi-aperture of the first to seventh lenses 110, 120, 130, 140, 150, 160, and 170 according to the second embodiment. Referring to Figures 3 and 4 and Table 5, the first lens 110 of the optical system 1000 according to the second embodiment can have a negative refractive power. The first surface S1 of the first lens 110 can be convex, and the second surface S2 can be concave. The first lens 110 can have a meniscus shape that bulges towards the object. The first surface S1 may be aspherical, and the second surface S2 may be aspherical. The second lens 120 can have a positive refractive power. The third surface S3 of the second lens 120 may be convex, and the fourth surface S4 may be convex. Both surfaces of the second lens 120 may be convex. The third surface S3 may be aspherical, and the fourth surface S4 may be aspherical. The third lens 130 may have a negative refractive power. The fifth surface S5 of the third lens 130 may be convex, and the sixth surface S6 may be concave. The third lens 130 may have a meniscus shape that bulges towards the object. The fifth surface S5 may be aspherical, and the sixth surface S6 may be aspherical.

[0075] The fourth lens 140 can have a positive (+) refractive power. The seventh surface S7 of the fourth lens 140 can be convex, and the eighth surface S8 can be convex. Both surfaces of the fourth lens 140 can be convex. The seventh surface S7 may be aspherical, and the eighth surface S8 may be aspherical. The fifth lens 150 can have a negative (-) refractive power. The ninth surface S9 of the fifth lens 150 can be concave, and the tenth surface S10 may be concave. Both surfaces of the fifth lens 150 can be concave. The ninth surface S9 may be aspherical, and the tenth surface S10 may be aspherical. The sixth lens 160 can have a positive (+) refractive power. The eleventh surface S11 of the sixth lens 160 can be convex, and the twelfth surface S12 can be concave. The sixth lens 160 may have a meniscus shape that bulges toward the object. The eleventh surface S11 may be aspherical, and the twelfth surface S12 may be aspherical. The seventh lens 170 may have a negative refractive power. The thirteenth surface S13 of the seventh lens 170 may be convex, and the fourteenth surface S14 may be concave. The seventh lens 170 may have a meniscus shape that bulges toward the object. The thirteenth surface S13 may be aspherical, and the fourteenth surface S14 may be aspherical.

[0076] In the optical system 1000 according to the second embodiment, the values ​​of the aspheric coefficients for each lens surface are as shown in Table 6 below. [Table 6] [Table 7] [Table 8] Table 7 shows the TTL (Total track length), BFL (Back focal length), F-number, ImgH, the focal lengths f1, f2, f3, f4, f5, f6, f7 of the first to seventh lenses 110, 120, 130, 140, 150, and 160 respectively, and the entrance pupil size (EPD), etc., for the optical system 1000 according to the second embodiment, corresponding to the items in the formulas described above. Table 8 shows the result values ​​for formulas 1 to 26 described above for the optical system 1000 according to the second embodiment. Referring to Table 8, it can be seen that the optical system 1000 according to the second embodiment satisfies at least one of formulas 1 to 26. In more detail, it can be seen that the optical system 1000 according to the second embodiment satisfies all of formulas 1 to 26.

[0077] As a result, the optical system 1000 according to the second embodiment is provided with a slimmer structure. Furthermore, the optical system 1000 has improved optical characteristics and can have aberration characteristics as shown in Figure 4. Specifically, Figure 4 is a graph of the aberration characteristics of the optical system 1000 according to the second embodiment, showing spherical aberration (Longitudinal Spherical Aberration), astigmatic field curves, and distortion measured from left to right. In Figure 4, the X axis can represent focal length (mm) and distortion (%), and the Y axis can represent image height. The graph for spherical aberration is for light in the wavelength bands of approximately 470 nm, 510 nm, 555 nm, 610 nm, and 650 nm, while the graphs for astigmatic field curves and distortion are for light in the 555 nm wavelength band.

[0078] The optical system 1000 according to the third embodiment will be described in more detail with reference to Figures 5 and 6. Figure 5 is a configuration diagram of the optical system according to the third embodiment, and Figure 6 is a graph illustrating the aberration characteristics of the optical system according to the third embodiment.

[0079] Referring to Figures 5 and 6, the optical system 1000 according to the third embodiment may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a seventh lens 170, and an image sensor 300, which are arranged sequentially from the object side to the image side. The first to seventh lenses 110, 120, 130, 140, 150, 160, and 170 are arranged sequentially along the optical axis OA of the optical system 1000.

[0080] In the optical system 1000 according to the third embodiment, the third surface S3 of the second lens 120 can function as an aperture. A filter 500 is placed between the plurality of lenses 100 and the image sensor 300. More specifically, the filter 500 is placed between the seventh lens 170 and the image sensor 300. [Table 9] Table 9 shows the radius of curvature, thickness, distance between lenses, refractive index, Abbe's number, and semi-aperture of the first to seventh lenses 110, 120, 130, 140, 150, 160, and 170 according to the third embodiment. Referring to Figures 5 and 6 and Table 9, the first lens 110 of the optical system 1000 according to the third embodiment can have a negative refractive power. The first surface S1 of the first lens 110 can be convex, and the second surface S2 can be concave. The first lens 110 can have a meniscus shape that bulges towards the object. The first surface S1 may be aspherical, and the second surface S2 may be aspherical. The second lens 120 can have a positive refractive power. The third surface S3 of the second lens 120 may be convex, and the fourth surface S4 may be convex. Both surfaces of the second lens 120 may be convex. The third surface S3 may be aspherical, and the fourth surface S4 may be aspherical. The third lens 130 may have a negative refractive power. The fifth surface S5 of the third lens 130 may be convex, and the sixth surface S6 may be concave. The third lens 130 may have a meniscus shape that bulges towards the object. The fifth surface S5 may be aspherical, and the sixth surface S6 may be aspherical.

[0081] The fourth lens 140 can have a positive (+) refractive power. The seventh surface S7 of the fourth lens 140 can be convex, and the eighth surface S8 can be convex. Both surfaces of the fourth lens 140 can be convex. The seventh surface S7 may be aspherical, and the eighth surface S8 may be aspherical. The fifth lens 150 can have a negative (-) refractive power. The ninth surface S9 of the fifth lens 150 can be concave, and the tenth surface S10 may be concave. Both surfaces of the fifth lens 150 can be concave. The ninth surface S9 may be aspherical, and the tenth surface S10 may be aspherical. The sixth lens 160 can have a positive (+) refractive power. The eleventh surface S11 of the sixth lens 160 can be convex, and the twelfth surface S12 can be concave. The sixth lens 160 may have a meniscus shape that bulges toward the object. The eleventh surface S11 may be aspherical, and the twelfth surface S12 may be aspherical. The seventh lens 170 may have a negative refractive power. The thirteenth surface S13 of the seventh lens 170 may be convex, and the fourteenth surface S14 may be concave. The seventh lens 170 may have a meniscus shape that bulges toward the object. The thirteenth surface S13 may be aspherical, and the fourteenth surface S14 may be aspherical.

[0082] In the optical system 1000 according to the third embodiment, the values ​​of the aspheric coefficients for each lens surface are as shown in Table 10 below. [Table 10] [Table 11] [Table 12] Table 11 shows the TTL (Total track length), BFL (Back focal length), F-number, ImgH, the focal lengths f1, f2, f3, f4, f5, f6, f7 of the first to seventh lenses 110, 120, 130, 140, 150, and 160 respectively, and the entrance pupil size (EPD), etc., for the optical system 1000 according to the third embodiment, corresponding to the items in the formulas described above. Table 12 shows the result values ​​for formulas 1 to 26 described above for the optical system 1000 according to the third embodiment. Referring to Table 12, it can be seen that the optical system 1000 according to the third embodiment satisfies at least one of formulas 1 to 26. In more detail, it can be seen that the optical system 1000 according to the third embodiment satisfies all of formulas 1 to 26.

[0083] As a result, the optical system 1000 according to the third embodiment is provided with a slimmer structure. Furthermore, the optical system 1000 has improved optical characteristics and can have aberration characteristics as shown in Figure 6. Specifically, Figure 6 is a graph of the aberration characteristics of the optical system 1000 according to the third embodiment, measuring spherical aberration (Longitudinal Spherical Aberration), astigmatic field curves, and distortion from left to right. In Figure 4, the X axis can represent focal length (mm) and distortion (%), and the Y axis can represent image height. The graph for spherical aberration is for light in the wavelength bands of approximately 470 nm, 510 nm, 555 nm, 610 nm, and 650 nm, while the graphs for astigmatic aberration and distortion are for light in the wavelength band of 555 nm. That is, the optical system 1000 according to the embodiment can satisfy at least one of the above-mentioned formulas. As a result, the optical system 1000 can improve its aberration characteristics by blocking unnecessary light rays entering the optical system 1000. This allows the optical system 1000 to have improved optical characteristics and a slimmer structure.

[0084] Figure 7 is a diagram illustrating how the camera module according to the embodiment is applied to a mobile terminal. Referring to Figure 7, the mobile terminal 1 may include a camera module 10 provided on its rear surface.

[0085] The camera module 10 may include an image capture function. The camera module 10 may also include at least one of the following functions: autofocus, zoom, and OIS. The camera module 10 can process still images or video frames obtained by the image sensor 300 in shooting mode or video call mode. The processed image frames are displayed on the display unit (not shown) of the mobile terminal 1 and stored in memory (not shown). Although not shown in the drawings, another camera module may be positioned on the front of the mobile terminal 1. 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. This allows the camera module 10 to have improved aberration characteristics and a slim structure. The mobile terminal 1 may further include an autofocus device 31. The autofocus device 31 may include an autofocus function utilizing a laser. The autofocus device 31 is primarily used under conditions where the autofocus function using the image from the camera module 10 is reduced, such as close-up shots of 10m or less or in dark environments. The autofocus device 31 may include a light-emitting section containing a VCSEL (Vertical Cavity Surface Emitting Laser) semiconductor element and a light-receiving section that converts light energy into electrical energy, such as a photodiode. The mobile terminal 1 may further include a flash module 33. The flash module 33 may include a light-emitting element that emits light internally. The flash module 33 can be activated by the camera operation of the mobile terminal or by user control.

[0086] The features, structures, and effects described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to one embodiment. Furthermore, the features, structures, and effects exemplified in each embodiment can be combined or modified and implemented in other embodiments by a person with ordinary skill in the art to which the embodiment belongs. Therefore, such combinations and modifications should be interpreted as being within the scope of the present invention. In addition, although the above has focused on embodiments, these are merely examples and do not limit the present invention. A person with ordinary skill in the art to which the present invention belongs can make various modifications and applications not exemplified above, as long as they do not deviate from the essential characteristics of these embodiments. For example, each component specifically presented in the embodiments can be modified and implemented. And the differences related to such modifications and applications should be interpreted as being within the scope of the present invention as defined in the appended claims.

Claims

1. It is composed of the first to seventh lenses arranged in sequence along the optical axis from the object side to the image side direction, The optical system is composed of seven lenses, The first lens has a negative refractive power, The second lens has a positive refractive power, The third lens has a negative refractive power, The seventh lens has a negative refractive power, The object side surface and the image side surface of the second lens have a convex shape, The image side surface of the third lens has a concave shape, The first lens has a meniscus shape bulging on the object side, The object side surface and the image side surface of the fourth lens have a convex shape, The object side surface and the image side surface of the fifth lens have a concave shape, The focal length of the first lens is f1, The effective focal length of the optical system is F, Satisfy Equation 1: -40 < f1 / F < -10, The first and third lenses satisfy the following Equation 2, optical system. [Equation 2] 0.7 < (SD L3S1) / (SD L1S1) < 0.95 (In Equation 2, SD L1S1 means the effective radius of the object side surface of the first lens, and SD L3S1 means the effective radius of the object side surface of the third lens.)

2. The absolute value of the focal length of the first lens is longer than the sum of the absolute values of the focal lengths of the second to seventh lenses, the optical system according to Claim 1.

3. The sixth lens has a positive refractive power, The object side surface of the sixth lens has a convex shape, and the image side surface has a concave shape, The radius of curvature of the object side surface of the sixth lens is L6R1, and the radius of curvature of the image side surface of the seventh lens is L7R2, Satisfy the formula: 1.05 < L6R1 / L7R2 < ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ [Equation 3] 0.8 < (SD L6S2) / (SD L7S1) < 0.95 (In Equation 3, SD L6S2 means the effective radius of the image-side surface of the sixth lens, and SD L7S1 means the effective radius of the object-side surface of the seventh lens.) The optical system according to claim 1 or 2, wherein the third and fourth lenses satisfy the following Equation 4. [Equation 4] 0.7 < (SD L3S2) / (SD L4S2) < 0.95 (In Equation 4, SD L3S2 means the effective radius of the image-side surface of the third lens, and SD L4S2 means the effective radius of the image-side surface of the fourth lens.)

7. The first lens includes a first inflection point disposed on the image-side surface, when the first inflection point starts from the optical axis and ends at the end of the image-side surface of the first lens, it is disposed at a position that is 55% to 85% based on the direction perpendicular to the optical axis, the radius of curvature of the image-side surface of the first lens is L1R2, and the radius of curvature of the object-side surface of the second lens is L2R1, The optical system according to claim 1 or 2, satisfying the formula: 1 < L1R2 / L2R1 < 1.

15.

8. The sixth lens has a meniscus shape bulging toward the object side, the sixth lens includes a second inflection point disposed on the object-side surface and a third inflection point disposed on the image-side surface, the radius of curvature of the object-side surface of the sixth lens is L6R1, and the radius of curvature of the image-side surface of the seventh lens is L7R2, The optical system according to claim 7, satisfying the formula: 1.05 < L6R1 / L7R2 < 1.

55.

9. when the second inflection point starts from the optical axis and ends at the end of the object-side surface of the sixth lens, it is disposed at a position that is 40% to 70% based on the direction perpendicular to the optical axis, when the third inflection point starts from the optical axis and ends at the end of the image-side surface of the sixth lens, it is disposed at a position that is 35% to 65% based on the direction perpendicular to the optical axis, The optical system according to claim 8.

10. The focal length of the second lens is f2, The optical system according to claim 1 or 2, satisfying the formula: 10 < |f1| / |f2| < 100.

11. The seventh lens has a meniscus shape bulging toward the object side, the seventh lens includes a fourth inflection point disposed on the object-side surface, when the fourth inflection point starts from the optical axis and ends at the end of the object-side surface of the seventh lens, it is disposed at a position that is 5% to 25% based on the direction perpendicular to the optical axis, The focal length of the seventh lens is f7, The optical system according to claim 10, satisfying the mathematical formula: 6 < f1 / f7 < 22.

12. The center thickness of the third lens is L3_CT, The center thickness of the fourth lens is L4_CT, The optical system according to claim 1 or 2, satisfying the mathematical formula: 0.6 < (L3_CT) / (L4_CT) < 1.

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