Optical system and camera module

Abstract

An optical system according to an embodiment of the present invention includes first to third lens groups arranged along the optical axis. The first lens group has a positive (+) refractive power, the second lens group has a negative (-) refractive power, the third lens group has a positive (+) refractive power, and the first to third lens groups include at least one lens having a negative (−) refractive power.

Description

Optical system and camera module

[0001] The present invention relates to an optical system for improved optical performance and a camera module including the same.

[0002] Camera modules capture objects and store them as images or videos, and are used in a variety of applications. In particular, camera modules are manufactured in ultra-small sizes and are used in portable devices such as smartphones, tablet PCs, and laptops, as well as drones and vehicles, providing a variety of functions.

[0003] For example, the optical system of a 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 may perform an autofocus (AF) function that automatically adjusts the distance between the image sensor and the imaging lens to align the focal length of the lens, and may perform a zooming function of zooming up or zooming out to increase or decrease the magnification of a distant object to take a picture through a zoom lens. In addition, the camera module adopts an image stabilization (IS) technology to correct or prevent shaking of the image caused by movement of the camera due to an unstable fixing device or movement of the user.

[0004] The most crucial element for these camera modules to capture images is the imaging lens that forms the image. Recently, interest in high-performance features such as high definition and resolution has been increasing, and research is underway on optical systems that incorporate multiple lenses to achieve these goals.

[0005] For example, research is being conducted using multiple imaging lenses with positive (+) or negative (-) refractive power to implement a high-performance optical system. An optical system including multiple lenses may have a set effective focal length (EFL). In this case, if the effective focal length (EFL) value is relatively large, the lens adjacent to the object side has a large aperture or has the largest aperture among the multiple lenses. Accordingly, since the lens closest to the object side has a relatively large size, there is a problem that it is difficult to miniaturize the optical system.

[0006] An optical system comprising multiple lenses can be relatively tall. For example, as the number of lenses increases, the distance between the image sensor and the object plane of the adjacent lens may increase. Consequently, the overall thickness of a mobile device, such as a smartphone, in which the optical system is positioned may increase, making miniaturization difficult.

[0007] Camera modules for close-range photography have shorter TTLs than conventional camera modules. Alternatively, camera modules for long-range photography have longer TTLs than conventional camera modules. However, portable terminals have limited installation space for camera modules, making it difficult to mount long-range camera modules or camera modules capable of adjusting the image magnification (zoom camera modules). Therefore, a new optical system capable of solving the aforementioned problems is required.

[0008] The present embodiment seeks to provide an optical system and camera module with improved optical characteristics.

[0009] In addition, it is possible to provide an optical system that can be implemented in a small and compact manner.

[0010] In addition, an optical system may be provided in which the lengths of at least one lens adjacent to the object side or adjacent to the outside of the terminal among a plurality of lenses are different in the first direction and the second direction. In other words, an optical system may be provided in which the lengths of at least one or more of the lenses are different in the directions of two axes that are orthogonal to each other.

[0011] Additionally, we aim to provide an optical system applicable to a folded camera or macro mode having a thin thickness or height.

[0012] In order to solve the above technical problem, an optical system according to an embodiment of the present invention includes first to third lens groups arranged along an optical axis, wherein the first lens group has positive (+) refractive power, the second lens group has negative (-) refractive power, the third lens group has positive (+) refractive power, and the first to third lens groups include at least one lens having negative (-) refractive power.

[0013] The first and second lens groups may be moving groups, and the third lens group may be a fixed group.

[0014] The object-side surface of the lens arranged on the most object-side of the first lens group on the optical axis may have a convex shape, and the object-side surface of the lens arranged on the most object-side of the third lens group on the optical axis may have a convex shape.

[0015] When the optical system operates from a wide-angle end to a telephoto end, the distance between the first lens group and the second lens group may increase, and the distance between the second lens group and the third lens group may decrease.

[0016] When the optical system operates from a wide-angle end to a telephoto end, the stroke length of the second lens group may be greater than the stroke length of the first lens group.

[0017] The first lens group may include a first lens and a second lens, the second lens group may include a third lens, a fourth lens, and a fifth lens, and the third lens group may include a sixth lens and a seventh lens.

[0018] The first lens may have positive (+) refractive power, the second lens may have negative (-) refractive power, the third lens may have negative (-) refractive power, the fourth lens may have positive (+) refractive power, the fifth lens may have negative (-) refractive power, the sixth lens may have positive (+) refractive power, and the seventh lens may have negative (-) refractive power.

[0019] A first optical path control member may be arranged on the object side of the first lens group, and a second optical path control member may be arranged between the third lens group and the image sensor.

[0020] The above first optical path control member may be a prism lens, and the above second optical path control member may be a mirror.

[0021] In order to solve the above technical problem, an optical system according to another embodiment of the present invention includes first to seventh lenses arranged along an optical axis, wherein the first lens has positive (+) refractive power, the second lens has negative (-) refractive power, the third lens has negative (-) refractive power, the fourth lens has positive (+) refractive power, the fifth lens has negative (-) refractive power, the sixth lens has positive (+) refractive power, and the seventh lens has negative (-) refractive power, wherein the first lens and the second lens are a first lens group which is a moving group, the third lens, the fourth lens, and the fifth lens are a second lens group which is a moving group, and the sixth lens and the seventh lens are a third lens group which is a fixed group.

[0022] The first lens group may have positive (+) refractive power, the second lens group may have negative (-) refractive power, and the third lens group may have positive (+) refractive power.

[0023] The object-side surface of the first lens on the optical axis may have a convex shape, and the object-side surface of the sixth lens on the optical axis may have a convex shape.

[0024] When the optical system operates from a wide-angle end to a telephoto end, the distance between the first lens group and the second lens group may increase, and the distance between the second lens group and the third lens group may decrease.

[0025] When the optical system operates from a wide-angle end to a telephoto end, the stroke length of the second lens group may be greater than the stroke length of the first lens group.

[0026] The following condition can be satisfied. <Condition> 0.3 < BFL / TTL < 0.5 (In the above condition, BFL is the optical axis distance from the image sensor to the center of the sensor-side surface of the seventh lens, and TTL is the optical axis distance from the object-side surface of the first lens to the upper surface of the image sensor.)

[0027] The optical system and camera module according to the present embodiment have various magnifications and can exhibit excellent optical characteristics when providing various magnifications. Specifically, the embodiment can control a lens group having a set number of lenses, a set refractive power, a plurality of lenses having set shapes and focal lengths, etc., a moving distance of a moving lens group, etc. to have various magnifications and can provide an autofocus (AF) function for the subject.

[0028] Additionally, each of the plurality of lens groups can compensate for aberration characteristics or mutually complement aberration characteristics that change with movement. Accordingly, the optical system according to the embodiment can minimize or prevent changes in chromatic aberration and aberration characteristics that occur when magnification changes.

[0029] Additionally, the effective focal length (EFL) can be controlled by moving only some of the lens groups among the plurality of lens groups, thereby minimizing the distance traveled by the moving lens groups. Accordingly, the embodiment can significantly reduce the distance traveled by the lens groups when the magnification changes, and minimize the power consumption required when moving the lens groups.

[0030] In addition, the optical system according to the present embodiment has improved optical characteristics and can have a large BFL (Back focal length), so that it can provide an optical system suitable for a folded camera module.

[0031] Figure 1 is a configuration diagram of an optical system according to the first embodiment operating in the first mode.

[0032] Figure 2 is a modular configuration diagram of an optical system according to the first embodiment operating in the first mode.

[0033] Figure 3 is a configuration diagram of an optical system according to the first embodiment operating in the second mode.

[0034] Figure 4 is a modular configuration diagram of an optical system according to the first embodiment operating in the second mode.

[0035] Figure 5 is a configuration diagram of an optical system according to the first embodiment operating in the third mode.

[0036] Figure 6 is a modular configuration diagram of an optical system according to the first embodiment operating in the third mode.

[0037] Figure 7 is a table showing the aspherical coefficients of lenses in the optical system according to the first embodiment.

[0038] Fig. 8 is a graph showing data on aberration characteristics of an optical system according to the first embodiment operating in the first mode.

[0039] Fig. 9 is a graph showing data on aberration characteristics of the optical system according to the first embodiment operating in the second mode.

[0040] Fig. 10 is a graph showing data on aberration characteristics of an optical system according to the first embodiment operating in the third mode.

[0041] Fig. 11 is a configuration diagram of an optical system according to the second embodiment operating in the first mode.

[0042] Fig. 12 is a modular configuration diagram of an optical system according to the second embodiment of the present invention operating in the first mode.

[0043] Fig. 13 is a configuration diagram of an optical system according to the second embodiment operating in the second mode.

[0044] Fig. 14 is a modular configuration diagram of an optical system according to the second embodiment operating in the second mode.

[0045] Fig. 15 is a configuration diagram of an optical system according to the second embodiment operating in the third mode.

[0046] Figure 16 is a modular configuration diagram of an optical system according to the second embodiment operating in the third mode.

[0047] Fig. 17 is a table showing the aspherical coefficients of lenses in the optical system according to the second embodiment.

[0048] Fig. 18 is a graph showing data on aberration characteristics of an optical system according to the second embodiment operating in the first mode.

[0049] Fig. 19 is a graph showing data on aberration characteristics of an optical system according to the second embodiment operating in the second mode.

[0050] Fig. 20 is a graph showing data on aberration characteristics of an optical system according to the second embodiment operating in the third mode.

[0051] Fig. 21 is a drawing for explaining the D-cut lens of the present invention.

[0052] Fig. 22 is an example of a portable terminal having an optical system according to the present embodiment.

[0053] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0054] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0055] In addition, terms (including technical and scientific terms) used in this embodiment may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which this embodiment belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0056] Additionally, the terms used in this embodiment are for the purpose of describing the embodiments and are not intended to limit the present invention.

[0057] In this specification, the singular may also include the plural unless specifically stated otherwise in the phrase, and when it is described as “A and / or at least one (or more) of B, C”, it may include one or more of all combinations that can be combined with A, B, C.

[0058] Additionally, in describing the components of this embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and are not intended to limit the nature, order, or sequence of the components.

[0059] And, when a component is described as being 'connected', 'coupled', or 'connected' to another component, it may include not only cases where the component is 'connected', 'coupled', or 'connected' directly to the other component, but also cases where the component is 'connected', 'coupled', or 'connected' by another component between the component and the other component.

[0060] Additionally, when described as being formed or arranged "above" or "below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when expressed as "above" or "below," the meaning may include not only the upward direction but also the downward direction based on one component.

[0061] In the description of the invention, the "object side" may mean a surface of the lens facing the object side with respect to the optical axis (OA), and the "sensor side" may mean a surface of the lens facing the imaging surface (image sensor) with respect to the optical axis. The "object side" may be the "object side," and the "sensor side" may be the "image side." A convex surface of a lens may mean a convex shape in the optical axis or the paraxial region, and a concave surface of a lens may mean a concave shape in the optical axis or the paraxial region. The radius of curvature, the center thickness, and the optical axis spacing between lenses described in the table for lens data may mean values ​​(unit: mm) in the optical axis. The vertical direction may mean a direction perpendicular to the optical axis, and the end of a lens or lens surface may mean the end of an effective area of ​​a lens through which incident light passes. The size of the effective diameter of the lens surface may have a measurement error of up to ±0.4 mm depending on the measurement method, etc. The above-mentioned near-axis region refers to a very narrow region near the optical axis, and is a region where the distance that a light ray falls from the optical axis (OA) is almost 0. Hereinafter, the meaning of the optical axis may include the center of each lens or a very narrow region near the optical axis.

[0062] The optical axis (OA) may refer to the central axis on the path of light along which light incident from a second direction (Y-axis direction) by a prism lens is bent into a first direction (X-axis direction).

[0063]

[0064] The optical system (1000, 1100) according to the first and second embodiments may include a plurality of lens groups. In detail, the optical system (1000, 1100) may include a plurality of lens groups each including at least one lens. For example, the optical system (1000, 1100) may include a first lens group (LG1), a second lens group (LG2), a third lens group (LG3), and an image sensor (300) that are sequentially arranged from the object side toward the image sensor.

[0065] The first to third lens groups (LG1, LG2, LG3) may each have positive (+) or negative (-) refractive power. The first lens group (LG1) and the second lens group (LG2) may have refractive powers of different signs. For example, the first lens group (LG1) may have positive (+) refractive power, and the second lens group (LG2) may have negative (-) refractive power. Additionally, the third lens group (LG3) may have positive (+) refractive power.

[0066] The first to third lens groups (LG1, LG2, LG3) may include at least one lens having negative (-) refractive power. Through this, light incident on each lens group may be guided to accurately enter the image sensor through appropriate refractive power distribution. Specifically, the second lens (101, 202) included in the first lens group (LG1) may have negative (-) refractive power, the third lens (103, 203) included in the second lens group (LG2) may have negative (-) refractive power, and the seventh lens (107, 207) included in the third lens group (LG3) may have negative (-) refractive power.

[0067]

[0068] At least one of the first lens group (LG1), the second lens group (LG2), and the third lens group (LG3) may be provided to be movable in the direction of the optical axis (OA). For example, the first lens group (LG1) and the second lens group (LG2) may be provided to be movable, and the third lens group (LG3) may be fixed. The third lens group (LG3) may be arranged at a fixed position, and the first lens group (LG1) and the second lens group (LG2) may be provided to be movable in the direction of the optical axis (OA).

[0069]

[0070] The first lens group (LG1) may include multiple lenses. Specifically, the first lens group (LG1) may include two or more lenses having opposite refractive powers. For example, the first lens group (LG1) may include two lenses.

[0071] The plurality of lenses included in the first lens group (LG1) may have a set interval. Specifically, the interval between the plurality of lenses included in the first lens group (LG1) may be constant and not change in the operation mode described later. For example, the interval between the first lens (101, 201) and the second lens (102, 202) may be constant and not change in the operation mode described later.

[0072] The second lens group (LG2) may include multiple lenses. Specifically, the second lens group (LG2) may include three or more lenses having opposite refractive powers. The number of lenses included in the second lens group (LG2) may be greater than the number of lenses included in the first lens group (LG1). For example, the second lens group (LG2) may include three lenses.

[0073] The plurality of lenses included in the second lens group (LG2) may have a set interval. In detail, the interval between the plurality of lenses included in the second lens group (LG2) may be constant without changing in the operation mode described later. For example, the interval between the third lens (103, 203) and the fourth lens (104, 204) and the interval between the fourth lens (104, 204) and the fifth lens (105, 205) may be constant without changing in the operation mode described later.

[0074] The third lens group (LG3) may include multiple lenses. Specifically, the third lens group (LG3) may include two or more lenses having opposite refractive powers. For example, the third lens group (LG3) may include two lenses.

[0075] The plurality of lenses included in the third lens group (LG3) may have a set spacing. Specifically, the spacing between the plurality of lenses included in the third lens group (LG3) may be constant and not change in the operation mode described below. For example, the spacing between the sixth lens (106, 206) and the seventh lens (107, 207) may be constant and not change in the operation mode described below.

[0076]

[0077] The optical system (1000, 1100) may include a plurality of lens groups (LG1, LG2, LG3) and an image sensor (300) sequentially arranged from the object side toward the sensor. In addition, the optical system (1000, 1100) may include a plurality of lenses included in the lens groups (LG1, LG2, LG3), for example, a first lens (101, 201), a second lens (102, 202), a third lens (103, 203), a fourth lens (104, 204), a fifth lens (105, 205), a sixth lens (106, 206), and a seventh lens (107, 207).

[0078] The first lens group (LG1) may include a first lens (101, 201) and a second lens (102, 202). The second lens group (LG2) may include a third lens (103, 203), a fourth lens (104, 204), and a fifth lens (105, 205). The third lens group (LG3) may include a sixth lens (106, 206) and a seventh lens (107, 207). The first to seventh lenses (101-107, 201-207) and the image sensor (300) may be sequentially arranged along the optical axis (OA) of the optical system (1000, 1100).

[0079] Each of the plurality of 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 first to seventh lenses (101-107, 201-207) passes. In other words, the effective area may be an area in which the incident light is refracted to implement optical characteristics.

[0080] The inactive area may be located around the active area. The inactive area may be an area where no light is incident. In other words, the inactive area may be an area unrelated to optical properties. Additionally, the inactive area may be an area fixed to a barrel (not shown) that accommodates the lens.

[0081] Referring to FIG. 21, at least one of the first to seventh lenses (101-107, 201-207) in the optical system (1000, 1100) according to the first and second embodiments may be subject to the D-cut technique. When the D-cut technique is applied, the height of the entire optical system may be reduced by cutting a portion of the lens effective diameter or rib. Here, the height of the entire optical system may mean the length in the direction perpendicular to the optical axis rather than the TTL. The D-cut lens may have a non-circular shape, and the length (A) in the second direction (Y-axis direction) and the length (B) in the first direction (X-axis direction) may be different.

[0082]

[0083] The image sensor (300) can detect light. The image sensor (300) can detect light that has sequentially passed through a plurality of lenses, for example, the first to seventh lenses (101-107, 201-207). The image sensor (300) may include a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor).

[0084] The optical system (1000, 1100) may further include a filter (400). The filter (400) may be arranged between a plurality of lenses and the image sensor (300). The filter (400) may be arranged between the third lens group (LG3) closest to the image sensor (300) among the plurality of lens groups (LG1, LG2, LG3) and the image sensor (300). For example, the filter (400) may be arranged between the seventh lens (107, 207), which is the last lens of the third lens group (LG3) closest to the image sensor (300) among the plurality of lenses, and the image sensor (300).

[0085] The filter (400) may include at least one optical filter, such as an infrared filter or a cover glass. The filter (400) may allow light of a set wavelength band to pass through and filter out light of a different wavelength band. When the filter (400) includes an infrared filter, it may block radiant heat emitted from external light from being transmitted to the image sensor (300). In addition, the filter (400) may transmit visible light and reflect infrared light.

[0086] The optical system (1000, 1100) may include an aperture (not shown). The aperture can control the amount of light incident on the optical system (1000, 1100).

[0087] The aperture may be positioned in front of the first lens (101, 201) or may be arranged between two lenses selected from the first to seventh lenses (101-107, 201-207). For example, the aperture may be arranged between the fifth lens (105, 205) and the sixth lens (106, 206). In addition, at least one lens selected from the first to seventh lenses (101-107, 201-207) may function as an aperture. For example, the object-side surface or the sensor-side surface of one lens selected from the first to seventh lenses (101-107, 201-207) may function as an aperture for controlling the amount of light.

[0088]

[0089] The optical system (1000, 1100) according to the first and second embodiments can be modularized by placing the first optical path control member (111) on the object side of the first lens (101, 201) or placing the second optical path control member (112) between the seventh lens (107, 207) and the filter (400) or between the seventh lens (107, 207) and the image sensor (300). That is, when placing the optical system (1000, 1100) in a camera module, the optical system can be modularized in order to reduce the overall size of the optical system.

[0090] The first optical path control member (111) may be a prism lens. The first optical path control member (111) may reduce the first direction (X-axis direction) and the second direction (Y-axis direction) of the optical system (1000, 1100). The first optical path control member (111) may change the path of light incident from the outside. The first optical path control member (111) may be a mirror. The first optical path control member (111) may rotate the optical path by 90 degrees. The first optical path control member (111) includes an incident surface (P1) on which light is incident, a reflective surface (RS1) that reflects the incident light, and an exit surface (P2) that emits the reflected light. The reflective surface (RS1) has an inclination angle of 45° and reflects the principal ray of the incident light at 90°, thereby reflecting the incident light to the third lens (103). The first light path control member (111) can reflect light incident in the second direction (Y-axis direction) and change the path of the light to the first direction (X-axis direction).

[0091] The second optical path control member (112) may be a mirror. The first optical path control member (111) may reduce the first direction (X-axis direction) and the second direction (Y-axis direction) of the optical system (1000, 1100). The second optical path control member (112) may change the path of light incident on the reflective surface. The second optical path control member (112) may be a prism lens. The second optical path control member (112) may rotate the optical path by 90°. The second optical path control member (112) includes a reflective surface that reflects light. The reflective surface has an inclination angle of 45° and reflects the principal ray of the incident light at 90°, thereby reflecting the incident light to the filter (400) or the image sensor (300). The second optical path control member (112) can reflect light incident in the first direction (X-axis direction) and change the path of the light to the second direction (Y-axis direction).

[0092] When the optical system (1000, 1100) does not include the first optical path control member (111) and the second optical path control member (112), a plurality of lenses may be arranged to extend in a direction perpendicular to the surface of the optical device within the optical device including the optical system (1000, 1100). Accordingly, the plurality of lenses may have a high height in a direction perpendicular to the surface of the optical device, and it may be difficult to form the optical device with an ultra-thin thickness. The prism lens may change light incident in a direction perpendicular to the plane of the optical device into a direction parallel to the surface of the optical device. That is, a plurality of lenses included in the optical system (1000) may be arranged to extend in a direction parallel to the surface of the optical device, and the optical device may be formed with a thin thickness.

[0093] Specifically, a prism lens has a refractive index because it functions to refract and reflect light, whereas a mirror has no refractive index because it functions to reflect light. When a prism lens or mirror is placed in front of the first lens, when a mirror is placed between the lenses, or when a mirror is placed between the lens closest to the sensor and the image sensor, there is no change in the overall performance of the optical system compared to when no prism lens or mirror is placed. In contrast, when a prism lens is placed between the lenses, or when a prism lens is placed between the lens closest to the sensor and the image sensor, there is a change in the overall performance of the optical system compared to when no prism lens or mirror is placed.

[0094] Therefore, under conditions where the overall performance of the optical system does not change depending on the additional placement of prism lenses or mirrors, the additional placement of prism lenses or mirrors may be an option for modularizing the optical system. Under these conditions, interference with other mechanisms or lenses may be considered, and the spacing and size of the placement may be determined by considering the magnitude of light incident on the optical path control member.

[0095] Furthermore, in conditions where the overall performance of the optical system changes due to the additional placement of prism lenses or mirrors, the additional placement of prism lenses or mirrors may be essential to ensure optical system performance. Under these conditions, optical performance changes depending on the size of the prism lenses or mirrors and the spacing between adjacent lenses, so the initial design conditions should not be arbitrarily changed.

[0096]

[0097] An optical system according to the first embodiment of the invention will be described.

[0098] FIG. 1 is a configuration diagram of an optical system according to the first embodiment of the present invention operating in a first mode, FIG. 2 is a modular configuration diagram of an optical system according to the first embodiment of the present invention operating in a first mode, FIG. 3 is a configuration diagram of an optical system according to the first embodiment of the present invention operating in a second mode, FIG. 4 is a modular configuration diagram of an optical system according to the first embodiment of the present invention operating in a second mode, FIG. 5 is a configuration diagram of an optical system according to the first embodiment of the present invention operating in a third mode, FIG. 6 is a modular configuration diagram of an optical system according to the first embodiment of the present invention operating in a third mode, FIG. 7 is a table showing aspherical coefficients of lenses in the optical system according to the first embodiment of the present invention, FIG. 8 is a graph showing data on aberration characteristics of an optical system according to the first embodiment of the present invention operating in a first mode, and FIG. 9 is a graph showing data on aberration characteristics of an optical system according to the first embodiment of the present invention operating in a second mode, and FIG. 10 is a graph showing data on the aberration characteristics of the optical system according to the first embodiment operating in the third mode.

[0099] Referring to FIG. 1, the optical system (1000) includes a lens unit, and the lens unit may include first to seventh lenses (101 to 107). The first to seventh lenses (101 to 107) may be sequentially arranged along the optical axis (OA) of the optical system (1000). Light corresponding to information about an object may pass through the first to seventh lenses (101 to 107) and the filter (400) and be incident on the image sensor (300).

[0100] The first lens (101) may be positioned closest to the object side. The first lens (101) may be positioned furthest from the sensor side. The first lens (101) may have positive refractive power. The first lens (101) may include a plastic or glass material. For example, the first lens (101) may be provided as a plastic material.

[0101] The first surface (S1) on the object side of the first lens (101) with respect to the optical axis may be convex, and the second surface (S2) on the sensor side may be convex. The first lens (101) may have a shape in which both sides are convex. The first lens (101) is made of a plastic material and may have an aspherical surface. The aspherical coefficients of the first surface (S1) and the second surface (S2) of the first lens (101) may be provided as L1S1 and L1S2 of FIG. 7. At least one or both of the first surface (S1) and the second surface (S2) of the first lens (101) may be provided without a critical point from the optical axis to the end of the effective area.

[0102]

[0103] The second lens (102) may be arranged second from the object side. The second lens (102) may be arranged sixth from the sensor side. The second lens (102) may be arranged between the third lens (103) and the fifth lens (105). The second lens (102) may have negative (-) refractive power. The second lens (102) may include a plastic or glass material. For example, the second lens (102) may be provided as a plastic material.

[0104] The third surface (S3) on the object side of the second lens (102) may be concave with respect to the optical axis, and the fourth surface (S4) on the sensor side may be convex. The second lens (102) may have a meniscus shape in which the object side is concave with respect to the optical axis (OA). The second lens (102) may have a meniscus shape in which the sensor side is convex with respect to the optical axis (OA). The second lens (102) may be made of a plastic material and may have an aspherical surface. The aspherical coefficients of the third surface (S3) and the fourth surface (S4) may be provided as L2S1 and L2S2 of FIG. 7. At least one or both of the third surface (S3) and the fourth surface (S4) of the second lens (102) may be provided without a critical point from the optical axis to the end of the effective area.

[0105]

[0106] The third lens (103) may be arranged third from the object side. The third lens (103) may be arranged fifth from the sensor side. The third lens (103) may be arranged between the third lens (103) and the fifth lens (105). The third lens (103) may have negative (-) refractive power. The third lens (103) may include a plastic or glass material. For example, the third lens (103) may be provided as a plastic material.

[0107] The fifth surface (S5) on the object side of the third lens (103) with respect to the optical axis is concave, and the sixth surface (S6) on the sensor side may be concave. The third lens (103) may have a shape in which both sides are concave. The third lens (103) is made of a plastic material and may have an aspherical surface. The aspherical coefficients of the fifth surface (S5) and the sixth surface (S6) may be provided as L3S1 and L3S2 of FIG. 7. At least one or both of the fifth surface (S5) and the sixth surface (S6) of the third lens (103) may be provided without a critical point from the optical axis to the end of the effective area.

[0108]

[0109] The fourth lens (104) may be arranged fourth from the object side. The fourth lens (104) may be arranged fourth from the sensor side. The fourth lens (104) may be arranged between the third lens (103) and the fifth lens (105). The fourth lens (104) may have positive (+) refractive power. The fourth lens (104) may include a plastic or glass material. For example, the fourth lens (104) may be provided as a plastic material.

[0110] The object-side seventh surface (S7) of the fourth lens (104) with respect to the optical axis may be convex, and the sensor-side eighth surface (S8) may be convex. The fourth lens (104) may have a convex shape on both sides. The fourth lens (104) may be made of a plastic material and may have an aspherical surface. The aspherical coefficients of the seventh surface (S7) and the eighth surface (S8) may be provided as L4S1 and L4S2 of FIG. 7. At least one or both of the seventh surface (S7) and the eighth surface (S8) of the fourth lens (104) may be provided without a critical point from the optical axis to the end of the effective area.

[0111]

[0112] The fifth lens (105) may be arranged as the fifth lens from the object side. The fifth lens (105) may be arranged as the third lens from the sensor side. The fifth lens (105) may be arranged between the fourth lens (104) and the sixth lens (106). The fifth lens (105) may have negative (-) refractive power. The fifth lens (105) may include a plastic or glass material. For example, the fifth lens (105) may be provided as a plastic material.

[0113] With respect to the optical axis (OA), the ninth surface (S9) on the object side of the fifth lens (105) may be concave, and the tenth surface (S10) on the sensor side may be concave. The fifth lens (105) may have a concave shape on both sides. The fifth lens (105) may be made of a plastic material and may have an aspherical surface. The aspherical coefficients of the ninth surface (S9) and the tenth surface (S10) may be provided as L5S1 and L5S2 of FIG. 7. At least one or both of the ninth surface (S9) and the tenth surface (S10) of the fifth lens (105) may be provided without a critical point from the optical axis to the end of the effective area.

[0114] The aperture (STOP) may be positioned between the fifth lens (105) and the sixth lens (106). The aperture may be positioned on the sensor-side tenth surface (S10) of the fifth lens (105) or the object-side eleventh surface (S11) of the sixth lens (106). The aperture can reduce the TTL within the field of view range and enable miniaturization of the optical system. Accordingly, a decrease in the yield by weight of the optical system can be prevented and production efficiency can be improved.

[0115]

[0116] The sixth lens (106) may be arranged as the sixth lens from the object side. The sixth lens (106) may be arranged as the second lens from the sensor side. The sixth lens (106) may be arranged between the fifth lens (105) and the seventh lens (107). The sixth lens (106) may have positive (+) refractive power. The sixth lens (106) may include a plastic or glass material. For example, the sixth lens (106) may be provided as a plastic material.

[0117] With respect to the optical axis (OA), the object-side eleventh surface (S11) of the sixth lens (106) may be convex, and the sensor-side twelfth surface (S12) may be convex. The sixth lens (106) may have a convex shape on both sides. The sixth lens (106) may be made of a plastic material and may have an aspherical surface. The aspherical coefficients of the eleventh surface (S11) and the twelfth surface (S12) may be provided as L6S1 and L6S2 of FIG. 7. At least one or both of the eleventh surface (S11) and the twelfth surface (S12) of the sixth lens (106) may be provided without a critical point from the optical axis to the end of the effective area.

[0118]

[0119] The seventh lens (107) may be arranged closest to the sensor side. The seventh lens (107) may be arranged farthest from the object side. The seventh lens (107) may be arranged between the sixth lens (106) and the filter (400). The seventh lens (107) may be arranged between the sixth lens (106) and the image sensor (300). The seventh lens (107) may have negative (-) refractive power. The seventh lens (107) may include a plastic or glass material. For example, the seventh lens (107) may be provided with a plastic material.

[0120] With respect to the optical axis (OA), the 13th surface (S13) on the object side of the seventh lens (107) may be concave, and the 14th surface (S14) on the sensor side may be convex. The seventh lens (107) may have a meniscus shape in which the object side is concave. The seventh lens (107) may have a meniscus shape in which the sensor side is convex. The seventh lens (107) is made of a plastic material and may have an aspherical surface. The aspherical coefficients of the 13th surface (S13) and the 14th surface (S14) may be provided as L7S1 and L7S2 of FIG. 7. The 13th surface (S13) of the seventh lens (107) may be provided without a critical point from the optical axis to the end of the effective area.

[0121] The fourteenth surface (S14) of the seventh lens (107) may have a critical point from the optical axis to the end of the effective area. When the fourteenth surface (S14) has a critical point, it may be located in a range of 30% to 50%, preferably 35% to 45%, of the effective radius from the optical axis. The critical point of the fourteenth surface (S14) may be located in a range of 0.5 mm to 2.0 mm, preferably 1.0 mm to 1.5 mm from the optical axis. The critical point of the fourteenth surface (S14) may be a point where the sign of the gradient value with respect to the optical axis and the direction perpendicular to the optical axis changes from positive (+) to negative (-) or from negative (-) to positive (+), and may mean a point where the gradient value is 0. In addition, the critical point of the fourteenth surface (S14) may be a point where the gradient value of a tangent passing through the lens surface increases and then decreases, or a point where the gradient value decreases and then increases.

[0122]

[0123] LensSurfaceRadiusThicknessndvdClearAperture1S124.2102.1001.54055.6009.500 S2-11.5400.780 9.4902S3-5.6601.1201.68019.2009.350 S4-7.410Variable (D1) 9.6203S5-12.0200.9401.62025.6007.800 S68.1100.900 7.1204S712.9101.8701.68019.2007.270 S8-12.1300.870 7.4105S9-32.2900.6501.54055.6006.800STOPS106.760Variable (D2) 6.5206S115.0303.0001.54055.6006.900 S12-10.2600.840 6.5207S13-7.0301.6001.67020.4006.050 S14-46.03016.400 5.560Filter Infinity Infinity Image Infinity

[0124] Table 1 shows the surface number (Surface), radius of curvature (Radius), center thickness of each lens or distance between lens surfaces (Thickness), refractive index (Index,nd), Abbe number (Abbe,vd), clear aperture, and focal length of the lens according to the first embodiment of the present invention. At this time, the unit of the radius of curvature and thickness or distance may be mm.

[0125]

[0126] Mode 1 Mode 2 Mode 3 D10.6204.3606.220 D26.7103.6000.500

[0127] Table 2 shows the distances (D1, D2) between lenses that are variable when the optical system according to the first embodiment of the present invention operates in any one of the first to third modes. Here, the first mode may refer to the wide-angle end, the second mode may refer to the middle end, and the third mode may refer to the telephoto end. The wide-angle end may be referred to as a wide angle, and the telephoto end may be referred to as a telephoto.

[0128] In the optical system according to the first embodiment of the present invention, the distance between adjacent lens groups may change during the process of changing the magnification from the first mode to the third mode. The third lens group (LG3) is fixed, and only the first and second lens groups (LG1, LG2) can move. The third lens group (LG3) may be a fixed group, and the first and second lens groups (LG1, LG2) may be movable groups.

[0129] When operating from the first mode to the second mode, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) may increase, and the distance (D2) between the second lens group (LG2) and the third lens group (LG3) may decrease.

[0130] When operating from the second mode to the third mode, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) may increase, and the distance (D2) between the second lens group (LG2) and the third lens group (LG3) may decrease.

[0131] When operating from the first mode to the third mode, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) may increase, and the distance (D2) between the second lens group (LG2) and the third lens group (LG3) may decrease.

[0132]

[0133] The stroke length of the first lens group (LG1) can satisfy 1 mm to 1.5 mm, and preferably, can satisfy about 1.240 mm. The stroke length of the second lens group (LG2) can satisfy 5 mm to 7 mm, and preferably, can satisfy about 6.210 mm.

[0134] The stroke length of the second lens group (LG2) may be greater than the stroke length of the first lens group (LG1). The first lens group (LG1) and the second lens group (LG2) may move at different speeds. The moving speed of the second lens group (LG2) may be greater than the moving speed of the first lens group (LG1). In the first embodiment, the magnification of the wide-angle end and the telephoto end can satisfy a range of 2 to 2.5 times, and can satisfy a magnification of about 2.37 times.

[0135] The CRA (1Field) deviation of the first mode and the third mode can satisfy 0.5 degrees or more and 5 degrees or less. Here, CRA (1Field) may mean the angle formed by the chief ray among the upper ray, the chief ray, and the lower ray, which are the rays incident on the 1 Field area of ​​the image sensor, and the normal perpendicular to the image sensor. The point where the image sensor and the optical axis meet may be 0 Field, and the most extreme point among the areas where light is incident on the image sensor may be 1 Field. If the CRA (1Field) deviation of the first mode and the third mode exceeds 5 degrees, the resolution deteriorates, and there is a problem that the distance between the third lens group (LG3) and the image sensor (300) becomes short, making it impossible to arrange the optical path control member. If the CRA (1Field) deviation of the first mode and the third mode is less than 0.5 degrees, there is a problem that the sensitivity increases according to the change in zoom magnification, resulting in a deterioration in optical performance.

[0136]

[0137] The first to third modes may be cases where an object located at infinity is photographed at the wide, mid, and telephoto ends. When photographing an object located at a close range (macroscopic) (for example, within 1000 mm), the first lens group (LG1) may move toward the object in the first to third modes. That is, when photographing an object located at infinity in the first to third modes and then photographing an object located at a close range, the first lens group (LG1) may move toward the object, so that the distance between the first lens group (LG1) and the second lens group (LG2) may increase. At this time, the stroke length of the first lens group (LG1) may satisfy 0.3 mm to 0.7 mm, and preferably 0.4 mm to 0.6 mm.

[0138]

[0139] EFL(f)_wide15.930BFL_wide16.400EFL(f)_mid23.890BFL_mid16.400EFL(f)_tele31.850BFL_tele16.400EPD_wide4.760SD_wide5.440EPD_mid7.130SD_mid5.440EPD_tele9.500SD_tele5.440Fno_wide3.300FOV_wide23.500Fno_mid3.400FOV_mid15.500Fno_tele3.400FOV_tele11.600f114.870ET10.780f2-47.620ET21.470f3-7.680ET32.510f49.500ET40.940f5-10.360ET51.540f66.750ET61.340f7-12.620ET72.150f_LG122.790TD_LG14.000f_LG2-8.340TD_LG25.230f_LG310.730TD_LG35.440CA_Max9.495L_CT_max3.000CA_Min5.805L_CT_min0.650CA_Aver7.565L_CT_aver1.611LG1_stroke1.240ΣCT11.280LG2_stroke6.210ΣCG10.720TTL38.410ImgH6.600

[0140] Table 3 shows the items of the mathematical formulas described above in the optical system (1000) of the first embodiment, and the effective focal length (F) (mm), BFL (Back Focal Length) (mm), EPD (mm), SD (mm), Fno, FOV (degree) which is the optical axis distance from the aperture (STOP) to the 14th surface (S14) at each of the wide, mid and telephoto ends of the optical system (1000), and the focal lengths (f1-f7) (mm), edge thicknesses (ET1-ET7) of the first to seventh lenses (101-107), the focal lengths (f_LG1, f_LG2, f_LG3) (mm) of the first to third lens groups (LG1, LG2, LG3), the stroke length (LG1_stroke) of the first lens group (LG1), and the stroke of the second lens group (LG2). The length (LG2_stroke), the total optical axis distance of the optical system (1000) TTL (mm), ImgH (mm), maximum effective diameter (CA_Max), minimum effective diameter (CA_Min), average effective diameter (CA_Aver), maximum center thickness (L_CT_max), minimum center thickness (L_CT_min), average center thickness (L_CT_aver) among the first to seventh lenses (101-107), and the length of each lens group in the optical axis direction (TD_LG1, TD_LG2, TD_LG3).

[0141]

[0142] Hereinafter, the center thicknesses of the first to seventh lenses (101 to 107) are represented as CT1 to CT7, the edge thicknesses at the ends of the effective areas of each lens are represented as ET1 to ET7, and the center gap between two adjacent lenses is represented as CG1 to CG6. The back focal length (BFL) is the optical axis distance from the image sensor (300) to the center of the last lens. The TTL is the optical axis distance from the center of the first surface (S1) of the first lens (101) to the upper surface of the image sensor (300).

[0143]

[0144] When comparing the absolute values ​​of the curvature radii of each lens, the curvature radii of the fourteenth surface (S14) of the seventh lens (107) on the optical axis (OA) may be the largest among the lenses, and the curvature radii of the eleventh surface (S11) of the sixth lens (106) may be the smallest among the lenses. The absolute value of the curvature radii of the first surface (S1) of the first lens (101) may be larger than the absolute value of the curvature radii of the second surface (S2). The absolute value of the curvature radii of the third surface (S3) of the second lens (102) may be smaller than the absolute value of the curvature radii of the fourth surface (S4). The absolute value of the curvature radii of the fifth surface (S5) of the third lens (103) may be larger than the absolute value of the curvature radii of the sixth surface (S6). The absolute value of the curvature radius of the seventh surface (S7) of the fourth lens (104) may be greater than the absolute value of the curvature radius of the eighth surface (S8). The absolute value of the curvature radius of the ninth surface (S9) of the fifth lens (105) may be greater than the absolute value of the curvature radius of the tenth surface (S10). The absolute value of the curvature radius of the eleventh surface (S11) of the sixth lens (106) may be less than the absolute value of the curvature radius of the twelfth surface (S12). The absolute value of the curvature radius of the thirteenth surface (S13) of the seventh lens (107) may be less than the absolute value of the curvature radius of the fourteenth surface (S14).

[0145]

[0146] Condition 1: 2 < |L1R1 / L1R2| < 2.5

[0147] Condition 2: 0.5 < |L2R1 / L2R2| < 1

[0148] Condition 3: 1 < |L3R1 / L3R2| < 1.5

[0149] Condition 4: 1 < |L4R1 / L4R2| < 1.5

[0150] Condition 5: 3 < |L5R1 / L5R2| < 5

[0151] Condition 6: 0.1 < |L6R1 / L6R2| < 0.5

[0152] Condition 7: 0.1 < |L7R1 / L7R2| < 0.5

[0153]

[0154] When describing the central thickness of the lenses based on the optical axis, the central thickness (CT6) of the sixth lens (106) is the largest among the lenses, and the central thickness (CT5) of the fifth lens (105) is the smallest among the lenses. The difference between the maximum and minimum central thicknesses among the lenses may be in the range of 2 mm or more and 2.5 mm or less.

[0155] The central thickness of each lens may satisfy any one of the following conditions:

[0156] Condition 1: CT6 > CT1 > CT2, CT3, CT4, CT5, CT7

[0157] Condition 2: CT1, CT4, CT6, CT7 > CT2 > CT3, CT5

[0158] Condition 3: CT1, CT2, CT4, CT6, CT7 > CT3 > CT5

[0159] Condition 4: CT1, CT6 > CT4 > CT2, CT3, CT5, CT7

[0160] Condition 5: CT1, CT2, CT3, CT4, CT6, CT7 > CT5

[0161] Condition 6: CT6 > CT1, CT2, CT3, CT4, CT5, CT7

[0162] Condition 7: CT1, CT4, CT6 > CT7 > CT2, CT3, CT5

[0163]

[0164] When zooming, the distance (CG1) between the first lens (101) and the second lens (102), the distance (CG3) between the third lens (103) and the fourth lens (104), the distance (CG4) between the fourth lens (104) and the fifth lens (105), and the distance (CG6) between the sixth lens (106) and the seventh lens (107) do not change, while the distance (CG2) between the second lens (102) and the third lens (103) and the distance (CG5) between the fifth lens (105) and the sixth lens (106) can change. Among the center distances between the lenses that do not change, the distance (CG3) between the third lens (103) and the fourth lens (104) can be the maximum, and the distance (CG1) between the first lens (101) and the second lens (102) can be the minimum. The difference between the maximum center spacing and the minimum center spacing among the lens spacings may be 0.1 mm or more, for example, in the range of 0.1 mm to 0.2 mm.

[0165] The center spacing between each lens can satisfy the conditions below.

[0166] Condition 1: CG3, CG4, CG6 > CG1

[0167] Condition 2: CG3 > CG1, CG4, CG6

[0168] Condition 3: CG3 > CG4 > CG1, CG6

[0169] Condition 4: CG3, CG4 > CG6 > CG1

[0170]

[0171] Regarding the effective diameter, the lens having the maximum effective diameter may be the first lens (101). Here, the effective diameter is the average of the effective diameters of the object-side surface and the sensor-side surface of each lens. The lens surface having the maximum effective diameter may be the first surface (S1) of the first lens (101). The lens having the minimum effective diameter may be the seventh lens (107). The lens surface having the minimum effective diameter may be the fourteenth surface (S14) of the seventh lens (107). The effective diameters of the first to seventh lenses (101-107) may be greater than the diagonal length of the image sensor (300).

[0172] The effective diameter of each lens can satisfy any one of the conditions below.

[0173] Condition 1: CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0174] Condition 2: CA_L1 > CA_L2 > CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0175] Condition 3: CA_L1, CA_L2 > CA_L3 > CA_L4, CA_L5, CA_L6, CA_L7

[0176] Condition 4: CA_L1, CA_L2, CA_L3 > CA_L4 > CA_L5, CA_L6, CA_L7

[0177] Condition 5: CA_L1, CA_L2, CA_L3, CA_L4, CA_L6 > CA_L5 > CA_L7

[0178] Condition 6: CA_L1, CA_L2, CA_L3, CA_L4 > CA_L6 > CA_L5, CA_L7

[0179] Condition 7: CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L6 > CA_L7

[0180]

[0181] In terms of refractive index, the refractive index of the second lens (102) and the fourth lens (104) may be the highest among the lenses and may be greater than 1.6, for example, greater than 1.65. Any one of the first lens (101), the fifth lens (105), and the sixth lens (106) may have the lowest refractive index among the lenses. For example, the refractive index of any one of the first lens (101), the fifth lens (105), and the sixth lens (106) may be the lowest among the lenses and may be less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index may be 0.1 or more.

[0182] The refractive index of each lens can satisfy any of the conditions below.

[0183] Condition 1: n2, n3, n4, n7 > n1 = n5 = n6

[0184] Condition 2: n2 = n4 > n1, n3, n5, n6, n7

[0185] Condition 3: n2, n4, n7 > n3 > n1, n5, n6

[0186] Condition 4: n2, n4 > n7 > n1, n3, n5, n6

[0187]

[0188] Comparing the Abbe numbers, the Abbe numbers of the first lens (101), the fifth lens (105), and the sixth lens (106) are the largest among the lenses and may be 50 or more. The Abbe numbers of the second lens (102) and the fourth lens (104) are the smallest among the lenses and may be 20 or less. The difference between the maximum refractive index and the minimum Abbe number may be 30 or more.

[0189] The Abbe number of each lens can satisfy any of the conditions below.

[0190] Condition 1: v1 = v5 = v6 > v2, v3, v4, v7

[0191] Condition 2: v1, v3, v5, v6, v7 > v2 = v4

[0192] Condition 3: v1, v5, v6 > v3 > v2, v4, v7

[0193] Condition 4: v1, v3, v5, v6 > v7 > v2, v4

[0194]

[0195] The focal lengths (F1, F4, F6) of the first, fourth, and sixth lenses (101, 104, and 106) may have positive (+) signs. The first, fourth, and sixth lenses (101, 104, and 106) may have positive (+) refractive power. The focal lengths (F2, F3, F5, and F7) of the second, third, fifth, and seventh lenses (102, 103, 105, and 107) may have negative (-) signs. The second, third, fifth, and seventh lenses (102, 103, 105, and 107) may have negative (-) refractive power. When comparing the focal lengths in absolute values, the focal length of the second lens (102) is the largest among the lenses and may be 40 or more and 60 or less. The focal length of the sixth lens (106) is the minimum among the lenses, and the absolute value of the focal length of the sixth lens (106) may be 5 or more and 8 or less.

[0196] The absolute value of the focal length of each lens can satisfy any of the conditions below.

[0197] Condition 1: |f2| > |f1| > |f3|, |f4|, |f5|, |f6|, |f7|

[0198] Condition 2: |f2| > |f1|, |f3|, |f4|, |f5|, |f6|, |f7|

[0199] Condition 3: |f1|, |f2|, |f4|, |f5|, |f7| > |f3| > |f6|

[0200] Condition 4: |f1|, |f2|, |f5|, |f7| > |f4| > |f3|, |f6|

[0201] Condition 5: |f1|, |f2|, |f7| > |f5| > |f3|, |f4|, |f6|

[0202] Condition 6: |f1|, |f2|, |f3|, |f4|, |f5|, |f7| > |f6|

[0203] Condition 7: |f1|, |f2| > |f7| > |f3|, |f4|, |f5|, |f6|

[0204]

[0205] The composite focal length (f_LG1) of the first lens group (LG1) can have a positive (+) sign. The first lens group (LG1) can have positive (+) composite refractive power. The composite focal length (f_LG2) of the second lens group (LG2) can have a negative (-) sign. The second lens group (LG2) can have negative (-) composite refractive power. The composite focal length (f_LG3) of the third lens group (LG3) can have a positive (+) sign. The third lens group (LG3) can have positive (+) composite refractive power. Through this, light incident from the object side can move away from the optical axis direction and then gather again in the optical axis direction, thereby forming a stable optical path.

[0206] When comparing the absolute values ​​of the composite focal lengths of the first to third lens groups (LG1, LG2, LG3), the composite focal length of the first lens group (LG1) may be the largest, and the composite focal length of the second lens group (LG2) may be the smallest. The relationship between the composite focal lengths of the first to third lens groups (LG1, LG2, LG3) may satisfy |f_LG1| > |f_LG3| > |f_LG2|.

[0207]

[0208] The thickness (CT1) of the first lens (101) may be at least 2.5 times the difference between the maximum thickness and the minimum thickness, for example, in the range of 2.5 to 3 times, and the center thickness (CT1) may be the maximum and the edge thickness (ET1) may be the minimum. The thickness (T2) of the second lens (102) may be minimum at the center and maximum at the edge, and the maximum thickness is in the range of 1 to 1.5 times the minimum thickness. The thickness (T3) of the third lens (103) may be minimum at the center and maximum at the edge, and the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T4) of the fourth lens (104) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T5) of the fifth lens (105) may be minimum at the center and maximum at the edge, and the maximum thickness is in the range of 2 to 2.5 times the minimum thickness. The thickness (T6) of the sixth lens (106) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 2 to 2.5 times the minimum thickness. The thickness (T7) of the seventh lens (107) may be minimum at the center and maximum at the edge, and the maximum thickness is in the range of 1 to 1.5 times the minimum thickness.

[0209]

[0210] The thickness of each lens can satisfy any of the conditions below.

[0211] Condition 1: 2.5 < CT1 / ET1 < 3, 0.1 < ET1 / CT1 < 0.5

[0212] Condition 2: 0.5 < CT2 / ET2 < 1, 1 < ET2 / CT2 < 1.5

[0213] Condition 3: 0.1 < CT3 / ET3 < 0.5, 2.5 < ET3 / CT3 < 3

[0214] Condition 4: 1.5 < CT4 / ET4 < 2, 0.5 < ET4 / CT4 < 1

[0215] Condition 5: 0.1 < CT5 / ET5 < 0.5, 2 < ET5 / CT5 < 2.5

[0216] Condition 6: 2 < CT6 / ET6 < 2.5, 0.1 < ET6 / CT6 < 0.5

[0217] Condition 7: 0.5 < CT7 / ET7 < 1, 1 < ET7 / CT7 < 1.5

[0218] Condition 8: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0219]

[0220] Among the gaps (G1-G6) between the lenses, the gap (LG1) between the first and second lenses (101, 102) may be maximum in the center and minimum at the edge. The gap (LG2) between the second and third lenses (102, 103) may be minimum in the center and maximum at the edge. The gap (LG3) between the third and fourth lenses (103, 104) may be maximum in the center and minimum at the edge. The gap (G4) between the fourth and fifth lenses (104, 105) may be maximum in the edge and minimum at the center. The fifth gap (G5) between the fifth and sixth lenses (105, 106) may be minimum in the center and maximum at the edge. The sixth gap (G6) between the sixth and seventh lenses (106, 107) may be maximum in the center and minimum at the edge.

[0221]

[0222] Fig. 8 is a graph showing data on aberration characteristics of an optical system according to the first embodiment operating in the first mode, Fig. 9 is a graph showing data on aberration characteristics of an optical system according to the first embodiment operating in the second mode, and Fig. 10 is a graph showing data on aberration characteristics of an optical system according to the first embodiment operating in the third mode. In the aberration graphs of Figs. 8, 9, and 10, spherical aberration (longitudinal spherical aberration), astigmatic field curves, and distortion are measured from left to right. In Figs. 8, 9, and 10, the X-axis may represent a focal length (mm) and a degree of distortion (%), and the Y-axis may represent the height of an image. In addition, the graph for spherical aberration is a graph for light in the wavelength bands of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for astigmatism and distortion is a graph for light in the wavelength band of about 546 nm. In the aberration diagrams of FIGS. 8, 9, and 10, it can be interpreted that the closer each curve is to the Y-axis, the better the aberration correction function is, and it can be seen that the optical system (1000) according to the first embodiment has measured values ​​close to the Y-axis in almost all areas. That is, the optical system (1000) according to the first embodiment has improved resolution and can have good optical performance not only in the center of the field of view (FOV) but also in the periphery.

[0223]

[0224] An optical system according to the second embodiment of the invention will be described.

[0225] FIG. 11 is a configuration diagram of an optical system according to the second embodiment of the present invention operating in the first mode, FIG. 12 is a configuration diagram of a modularized optical system according to the second embodiment of the present invention operating in the first mode, FIG. 13 is a configuration diagram of an optical system according to the second embodiment of the present invention operating in the second mode, FIG. 14 is a configuration diagram of a modularized optical system according to the second embodiment of the present invention operating in the second mode, FIG. 15 is a configuration diagram of an optical system according to the second embodiment of the present invention operating in the third mode, FIG. 16 is a configuration diagram of a modularized optical system according to the second embodiment of the present invention operating in the third mode, FIG. 17 is a table showing aspherical coefficients of lenses in the optical system according to the second embodiment of the present invention, FIG. 18 is a graph showing data on aberration characteristics of the optical system according to the second embodiment of the present invention operating in the first mode, and FIG. 19 is aberrations of the optical system according to the second embodiment of the present invention operating in the second mode. This is a graph showing data on characteristics, and FIG. 20 is a graph showing data on aberration characteristics of the optical system according to the second embodiment operating in the third mode.

[0226] Referring to FIG. 11, the optical system (1100) includes a lens unit, and the lens unit may include first to seventh lenses (201 to 207). The first to seventh lenses (201 to 207) may be sequentially arranged along the optical axis (OA) of the optical system (1100). Light corresponding to information about an object may pass through the first to seventh lenses (201 to 207) and the filter (400) and be incident on the image sensor (300).

[0227] The first lens (201) may be positioned closest to the object side. The first lens (201) may be positioned furthest from the sensor side. The first lens (201) may have positive refractive power. The first lens (201) may include a plastic or glass material. For example, the first lens (201) may be provided as a plastic material.

[0228] The first surface (S1) on the object side of the first lens (201) with respect to the optical axis may be convex, and the second surface (S2) on the sensor side may be convex. The first lens (201) may have a shape in which both sides are convex. The first lens (201) is made of a plastic material and may have an aspherical surface. The aspherical coefficients of the first surface (S1) and the second surface (S2) of the first lens (201) may be provided as L1S1 and L1S2 of FIG. 3. At least one or both of the first surface (S1) and the second surface (S2) of the first lens (201) may be provided without a critical point from the optical axis to the end of the effective area.

[0229]

[0230] The second lens (202) may be arranged second from the object side. The second lens (202) may be arranged sixth from the sensor side. The second lens (202) may be arranged between the third lens (203) and the fifth lens (205). The second lens (202) may have negative refractive power. The second lens (202) may include a plastic or glass material. For example, the second lens (202) may be provided as a plastic material.

[0231] The third surface (S3) on the object side of the second lens (202) may be concave with respect to the optical axis, and the fourth surface (S4) on the sensor side may be convex. The second lens (202) may have a meniscus shape in which the object side is concave with respect to the optical axis (OA). The second lens (202) may have a meniscus shape in which the sensor side is convex with respect to the optical axis (OA). The second lens (202) may be made of a plastic material and may have an aspherical surface. The aspherical coefficients of the third surface (S3) and the fourth surface (S4) may be provided as L2S1 and L2S2 of FIG. 3. At least one or both of the third surface (S3) and the fourth surface (S4) of the second lens (202) may be provided without a critical point from the optical axis to the end of the effective area.

[0232]

[0233] The third lens (203) may be arranged third from the object side. The third lens (203) may be arranged fifth from the sensor side. The third lens (203) may be arranged between the third lens (203) and the fifth lens (205). The third lens (203) may have negative (-) refractive power. The third lens (203) may include a plastic or glass material. For example, the third lens (203) may be provided as a plastic material.

[0234] The fifth surface (S5) on the object side of the third lens (203) with respect to the optical axis may be convex, and the sixth surface (S6) on the sensor side may be concave. The third lens (203) may have a meniscus shape in which the object side is convex. The third lens (203) may have a meniscus shape in which the sensor side is concave. The third lens (203) is made of a plastic material and may have an aspherical surface. The aspherical coefficients of the fifth surface (S5) and the sixth surface (S6) may be provided as L3S1 and L3S2 of FIG. 3. At least one or both of the fifth surface (S5) and the sixth surface (S6) of the third lens (203) may be provided without a critical point from the optical axis to the end of the effective area.

[0235]

[0236] The fourth lens (204) may be arranged fourth from the object side. The fourth lens (204) may be arranged fourth from the sensor side. The fourth lens (204) may be arranged between the third lens (203) and the fifth lens (205). The fourth lens (204) may have positive refractive power. The fourth lens (204) may include a plastic or glass material. For example, the fourth lens (204) may be provided as a plastic material.

[0237] The seventh surface (S7) on the object side of the fourth lens (204) with respect to the optical axis may be convex, and the eighth surface (S8) on the sensor side may be convex. The fourth lens (204) may have a shape in which both sides are convex. The fourth lens (204) is made of a plastic material and may have an aspherical surface. The aspherical coefficients of the seventh surface (S7) and the eighth surface (S8) may be provided as L4S1 and L4S2 of FIG. 3. At least one or both of the seventh surface (S7) and the eighth surface (S8) of the fourth lens (204) may be provided without a critical point from the optical axis to the end of the effective area.

[0238]

[0239] The fifth lens (205) may be arranged as the fifth lens from the object side. The fifth lens (205) may be arranged as the third lens from the sensor side. The fifth lens (205) may be arranged between the fourth lens (204) and the sixth lens (206). The fifth lens (205) may have negative (-) refractive power. The fifth lens (205) may include a plastic or glass material. For example, the fifth lens (205) may be provided as a plastic material.

[0240] With respect to the optical axis (OA), the ninth surface (S9) on the object side of the fifth lens (205) may be concave, and the tenth surface (S10) on the sensor side may be concave. The fifth lens (205) may have a concave shape on both sides. The fifth lens (205) may be made of a plastic material and may have an aspherical surface. The aspherical coefficients of the ninth surface (S9) and the tenth surface (S10) may be provided as L5S1 and L5S2 of FIG. 3. At least one or both of the ninth surface (S9) and the tenth surface (S10) of the fifth lens (205) may be provided without a critical point from the optical axis to the end of the effective area.

[0241] The aperture (STOP) may be positioned between the fifth lens (205) and the sixth lens (206). The aperture may be positioned on the sensor-side tenth surface (S10) of the fifth lens (205) or the object-side eleventh surface (S11) of the sixth lens (206). The aperture can reduce the TTL within the field of view range and enable miniaturization of the optical system. Accordingly, a decrease in the yield by weight of the optical system can be prevented and production efficiency can be improved.

[0242]

[0243] The sixth lens (206) may be arranged as the sixth lens from the object side. The sixth lens (206) may be arranged as the second lens from the sensor side. The sixth lens (206) may be arranged between the fifth lens (205) and the seventh lens (207). The sixth lens (206) may have positive (+) refractive power. The sixth lens (206) may include a plastic or glass material. For example, the sixth lens (206) may be provided as a plastic material.

[0244] With respect to the optical axis (OA), the object-side eleventh surface (S11) of the sixth lens (206) may be convex, and the sensor-side twelfth surface (S12) may be convex. The sixth lens (206) may have a convex shape on both sides. The sixth lens (206) may be made of a plastic material and may have an aspherical surface. The aspherical coefficients of the eleventh surface (S11) and the twelfth surface (S12) may be provided as L6S1 and L6S2 of FIG. 3. At least one or both of the eleventh surface (S11) and the twelfth surface (S12) of the sixth lens (206) may be provided without a critical point from the optical axis to the end of the effective area.

[0245]

[0246] The seventh lens (207) may be arranged closest to the sensor side. The seventh lens (207) may be arranged farthest from the object side. The seventh lens (207) may be arranged between the sixth lens (206) and the filter (400). The seventh lens (207) may be arranged between the sixth lens (206) and the image sensor (300). The seventh lens (207) may have negative (-) refractive power. The seventh lens (207) may include a plastic or glass material. For example, the seventh lens (207) may be provided with a plastic material.

[0247] With respect to the optical axis (OA), the 13th surface (S13) on the object side of the seventh lens (207) may be concave, and the 14th surface (S14) on the sensor side may be convex. The seventh lens (207) may have a meniscus shape in which the object side is concave. The seventh lens (207) may have a meniscus shape in which the sensor side is convex. The seventh lens (207) is made of a plastic material and may have an aspherical surface. The aspherical coefficients of the 13th surface (S13) and the 14th surface (S14) may be provided as L7S1 and L7S2 of FIG. 3. The 13th surface (S13) of the seventh lens (207) may be provided without a critical point from the optical axis to the end of the effective area.

[0248] The fourteenth surface (S14) of the seventh lens (207) may have a critical point from the optical axis to the end of the effective area. When the fourteenth surface (S14) has a critical point, it may be located in a range of 30% to 50%, preferably 35% to 45%, of the effective radius from the optical axis. The critical point of the fourteenth surface (S14) may be located in a range of 0.5 mm to 2.0 mm, preferably 1.0 mm to 1.5 mm from the optical axis. The critical point of the fourteenth surface (S14) may be a point where the sign of the gradient value with respect to the optical axis and the direction perpendicular to the optical axis changes from positive (+) to negative (-) or from negative (-) to positive (+), and may mean a point where the gradient value is 0. In addition, the critical point of the fourteenth surface (S14) may be a point where the gradient value of a tangent passing through the lens surface increases and then decreases, or a point where the gradient value decreases and then increases.

[0249]

[0250] LensSurfaceRadiusThicknessndvdClearAperture1S128.6902.3401.54055.6007.300 S2-11.3400.480 7.3402S3-8.9900.9501.68019.2007.230 S4-12.920Variable (D1) 7.4103S5220.8500.8001.62025.6006.410 S66.4600.990 5.9704S715.0701.7801.68019.2006.350 S8-13.2101.270 6.4805S9-20.1700.6901.54055.6006.330STOPS105.540Variable (D2) 6.5706S115.3603.0001.54055.6007.300 S12-8.2600.760 6.9507S13-5.6902.2301.67020.4006.620 S14-15.66015.770 6.110Filter Infinity Infinity Image Infinity

[0251] Table 4 shows the surface number (Surface), radius of curvature (Radius), center thickness of each lens or distance between lens surfaces (Thickness), refractive index (Index,nd), Abbe number (Abbe,vd), clear aperture, and focal length of the lens according to the second embodiment of the present invention. At this time, the unit of the radius of curvature and thickness or distance may be mm.

[0252]

[0253] Mode 1 Mode 2 Mode 3 D10.2503.8605.660 D26.4803.4900.500

[0254] Table 5 shows the distances (D1, D2) between lenses that are variable when the optical system according to the second embodiment of the present invention operates in any one of the first to third modes. Here, the first mode may refer to the wide-angle end, the second mode may refer to the middle end, and the third mode may refer to the telephoto end. The wide-angle end may be referred to as a wide angle, and the telephoto end may be referred to as a telephoto.

[0255] In the optical system according to the second embodiment of the present invention, the distance between adjacent lens groups may change during the process of changing the magnification from the first mode to the third mode. The third lens group (LG3) is fixed, and only the first and second lens groups (LG1, LG2) can move. The third lens group (LG3) may be a fixed group, and the first and second lens groups (LG1, LG2) may be movable groups.

[0256] When operating from the first mode to the second mode, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) may increase, and the distance (D2) between the second lens group (LG2) and the third lens group (LG3) may decrease.

[0257] When operating from the second mode to the third mode, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) may increase, and the distance (D2) between the second lens group (LG2) and the third lens group (LG3) may decrease.

[0258] When operating from the first mode to the third mode, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) may increase, and the distance (D2) between the second lens group (LG2) and the third lens group (LG3) may decrease.

[0259] The stroke length of the first lens group (LG1) can satisfy 1 mm to 1.5 mm, and preferably, can satisfy about 1.190 mm. The stroke length of the second lens group (LG2) can satisfy 5 mm to 7 mm, and preferably, can satisfy about 5.970 mm.

[0260] The stroke length of the second lens group (LG2) may be greater than the stroke length of the first lens group (LG1). The first lens group (LG1) and the second lens group (LG2) may move at different speeds. The moving speed of the second lens group (LG2) may be greater than the moving speed of the first lens group (LG1). In the second embodiment, the magnification of the wide-angle end and the telephoto end can satisfy a range of 1.8x to 2.3x, and can satisfy a magnification of approximately 1.99x.

[0261] The CRA (1Field) deviation of the first mode and the third mode can satisfy 0.5 degrees or more and 5 degrees or less. Here, the CRA (1Field) may refer to the angle formed by the chief ray among the upper ray, the chief ray, and the lower ray, which are the rays incident on the 1 Field area of ​​the image sensor, and the normal perpendicular to the image sensor. The point where the image sensor and the optical axis meet may be 0 Field, and the end point of the image sensor may be 1 Field. If the CRA (1Field) deviation of the first mode and the third mode exceeds 5 degrees, the resolution deteriorates, and the distance between the third lens group (LG3) and the image sensor (300) becomes short, which causes a problem in that the optical path control member cannot be arranged. If the CRA (1Field) deviation of the first mode and the third mode is less than 0.5 degrees, the sensitivity increases according to the change in zoom magnification, which causes a problem in that the optical performance deteriorates.

[0262]

[0263] The first to third modes may be cases where an object located at infinity is photographed at the wide, mid, and telephoto ends. When photographing an object located at a close range (macroscopic) (for example, within 1000 mm), the first lens group (LG1) may move toward the object in the first to third modes. That is, when photographing an object located at infinity in the first to third modes and then photographing an object located at a close range, the first lens group (LG1) may move toward the object, so that the distance between the first lens group (LG1) and the second lens group (LG2) may increase. At this time, the stroke length of the first lens group (LG1) may satisfy 0.3 mm to 0.7 mm, and preferably 0.4 mm to 0.6 mm.

[0264]

[0265] EFL(f)_wide15.930BFL_wide15.770EFL(f)_mid23.890BFL_mid15.770EFL(f)_tele31.850BFL_tele15.770EPD_wide5.440SD_wide5.990EPD_mid7.300SD_mid5.990EPD_tele7.300SD_tele5.990Fno_wide2.900FOV_wide22.200Fno_mid3.300FOV_mid14.800Fno_tele4.400FOV_tele11.100f115.470ET11.580f2-48.240ET21.140f3-10.750ET31.590f410.640ET41.080f5-8.030ET51.740f66.560ET61.180f7-14.670ET72.770f_LG123.140TD_LG13.770f_LG2-8.050TD_LG25.530f_LG310.340TD_LG35.990CA_Max7.320L_CT_max3.000CA_Min6.190L_CT_min0.690CA_Aver6.741L_CT_aver1.684LG1_stroke1.190ΣCT11.790LG2_stroke5.970ΣCG10.230TTL37.800ImgH6.300

[0266] Table 6 shows the items of the mathematical formulas described above in the optical system (1100) of the second embodiment, and the effective focal length (F) (mm), BFL (Back Focal Length) (mm), EPD (mm), SD (mm), Fno, FOV (degree) which is the optical axis distance from the aperture (STOP) to the 14th surface (S14) at each of the wide, mid and telephoto ends of the optical system (1100), and the focal lengths (f1-f7) (mm), edge thicknesses (ET1-ET7) of the first to seventh lenses (201-207), the focal lengths (f_LG1, f_LG2, f_LG3) (mm) of the first to third lens groups (LG1, LG2, LG3), the stroke length (LG1_stroke) of the first lens group (LG1), and the stroke of the second lens group (LG2). The length (LG2_stroke), the total optical axis distance of the optical system (1100) TTL (mm), ImgH (mm), maximum effective diameter (CA_Max), minimum effective diameter (CA_Min), average effective diameter (CA_Aver), maximum center thickness (L_CT_max), minimum center thickness (L_CT_min), average center thickness (L_CT_aver) among the first to seventh lenses (201-207), and the length of each lens group in the optical axis direction (TD_LG1, TD_LG2, TD_LG3).

[0267]

[0268] Hereinafter, the center thicknesses of the first to seventh lenses (201 to 207) are represented as CT1 to CT7, the edge thicknesses at the ends of the effective areas of each lens are represented as ET1 to ET7, and the center gap between two adjacent lenses is represented as CG1 to CG6. The back focal length (BFL) is the optical axis distance from the image sensor (300) to the center of the last lens. The TTL is the optical axis distance from the center of the first surface (S1) of the first lens (201) to the upper surface of the image sensor (300).

[0269]

[0270] When comparing the absolute values ​​of the curvature radii of each lens, the curvature radii of the fifth surface (S5) of the third lens (203) on the optical axis (OA) may be the largest among the lenses, and the curvature radii of the eleventh surface (S11) of the sixth lens (206) may be the smallest among the lenses. The absolute value of the curvature radii of the first surface (S1) of the first lens (201) may be larger than the absolute value of the curvature radii of the second surface (S2). The absolute value of the curvature radii of the third surface (S3) of the second lens (202) may be smaller than the absolute value of the curvature radii of the fourth surface (S4). The absolute value of the curvature radii of the fifth surface (S5) of the third lens (203) may be larger than the absolute value of the curvature radii of the sixth surface (S6). The absolute value of the curvature radius of the seventh surface (S7) of the fourth lens (204) may be greater than the absolute value of the curvature radius of the eighth surface (S8). The absolute value of the curvature radius of the ninth surface (S9) of the fifth lens (205) may be greater than the absolute value of the curvature radius of the tenth surface (S10). The absolute value of the curvature radius of the eleventh surface (S11) of the sixth lens (206) may be less than the absolute value of the curvature radius of the twelfth surface (S12). The absolute value of the curvature radius of the thirteenth surface (S13) of the seventh lens (207) may be less than the absolute value of the curvature radius of the fourteenth surface (S14).

[0271]

[0272] Condition 1: 2.5 < |L1R1 / L1R2| < 3

[0273] Condition 2: 0.5 < |L2R1 / L2R2| < 1

[0274] Condition 3: 30 < |L3R1 / L3R2| < 40

[0275] Condition 4: 1 < |L4R1 / L4R2| < 1.5

[0276] Condition 5: 3 < |L5R1 / L5R2| < 5

[0277] Condition 6: 0.5 < |L6R1 / L6R2| < 1

[0278] Condition 7: 0.1 < |L7R1 / L7R2| < 0.5

[0279]

[0280] When describing the central thickness of the lenses based on the optical axis, the central thickness (CT6) of the sixth lens (206) is the largest among the lenses, and the central thickness (CT5) of the fifth lens (205) is the smallest among the lenses. The difference between the maximum and minimum central thicknesses among the lenses may be in the range of 2 mm or more and 2.5 mm or less.

[0281] The central thickness of each lens may satisfy any one of the following conditions:

[0282] Condition 1: CT6 > CT1 > CT2, CT3, CT4, CT5, CT7

[0283] Condition 2: CT1, CT4, CT6, CT7 > CT2 > CT3, CT5

[0284] Condition 3: CT1, CT2, CT4, CT6, CT7 > CT3 > CT5

[0285] Condition 4: CT1, CT6, CT7 > CT4 > CT2, CT3, CT5

[0286] Condition 5: CT1, CT2, CT3, CT4, CT6, CT7 > CT5

[0287] Condition 6: CT6 > CT1, CT2, CT3, CT4, CT5, CT7

[0288] Condition 7: CT1, CT6 > CT7 > CT2, CT3, CT4, CT5

[0289]

[0290] When zooming, the distance (CG1) between the first lens (201) and the second lens (202), the distance (CG3) between the third lens (203) and the fourth lens (204), the distance (CG4) between the fourth lens (204) and the fifth lens (205), and the distance (CG6) between the sixth lens (206) and the seventh lens (207) do not change, while the distance (CG2) between the second lens (202) and the third lens (203) and the distance (CG5) between the fifth lens (205) and the sixth lens (206) can change. Among the center distances between the lenses that do not change, the distance (CG4) between the fourth lens (204) and the fifth lens (205) can be the maximum, and the distance (CG1) between the first lens (201) and the second lens (202) can be the minimum. The difference between the maximum center spacing and the minimum center spacing among the lens spacings may be 0.5 mm or more, for example, in the range of 0.5 mm to 1 mm.

[0291] The center spacing between each lens can satisfy the conditions below.

[0292] Condition 1: CG3, CG4, CG6 > CG1

[0293] Condition 2: CG4 > CG3 > CG1, CG6

[0294] Condition 3: CG4 > CG1, CG3, CG6

[0295] Condition 4: CG3, CG4 > CG6 > CG1

[0296]

[0297] Regarding the effective diameter, the lenses having the maximum effective diameter may be the first lens (201) and the second lens (202). Here, the effective diameter is the average of the effective diameters of the object-side surface and the sensor-side surface of each lens. The lens surface having the maximum effective diameter may be the fourth surface (S4) of the second lens (202). The lens having the minimum effective diameter may be the third lens (203). The lens surface having the minimum effective diameter may be the sixth surface (S6) of the third lens (203). The effective diameters of the first to seventh lenses (201-207) may be greater than the diagonal length of the image sensor (300).

[0298] The effective diameter of each lens can satisfy any one of the conditions below.

[0299] Condition 1: CA_L1 = CA_L2 > CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0300] Condition 2: CA_L1, CA_L2, CA_L4, CA_L5, CA_L6, CA_L7 > CA_L3

[0301] Condition 3: CA_L1, CA_L2, CA_L5, CA_L6 > CA_L4 > CA_L3, CA_L7

[0302] Condition 4: CA_L1, CA_L2, CA_L6 > CA_L5 > CA_L3, CA_L4, CA_L7

[0303] Condition 5: CA_L1, CA_L2 > CA_L6 > CA_L3, CA_L4, CA_L5, CA_L7

[0304] Condition 6: CA_L1, CA_L2, CA_L4, CA_L5, CA_L6 > CA_L7 > CA_L3

[0305]

[0306] In terms of refractive indices, the refractive indices of the second lens (202) and the fourth lens (204) may be the largest among the lenses and may be greater than 1.6, for example, greater than 1.65. Any one of the first lens (201), the fifth lens (205), and the sixth lens (206) may have the smallest refractive index among the lenses. For example, the refractive index of any one of the first lens (201), the fifth lens (205), and the sixth lens (206) may be the smallest among the lenses and may be less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index may be 0.1 or more.

[0307] The refractive index of each lens can satisfy any of the conditions below.

[0308] Condition 1: n2, n3, n4, n7 > n1 = n5 = n6

[0309] Condition 2: n2 = n4 > n1, n3, n5, n6, n7

[0310] Condition 3: n2, n4, n7 > n3 > n1, n5, n6

[0311] Condition 4: n2, n4 > n7 > n1, n3, n5, n6

[0312]

[0313] Comparing the Abbe numbers, the Abbe numbers of the first lens (201), the fifth lens (205), and the sixth lens (206) are the largest among the lenses and may be 50 or more. The Abbe numbers of the second lens (202) and the fourth lens (204) are the smallest among the lenses and may be 20 or less. The difference between the maximum refractive index and the minimum Abbe number may be 30 or more.

[0314] The Abbe number of each lens can satisfy any of the conditions below.

[0315] Condition 1: v1 = v5 = v6 > v2, v3, v4, v7

[0316] Condition 2: v1, v3, v5, v6, v7 > v2 = v4

[0317] Condition 3: v1, v5, v6 > v3 > v2, v4, v7

[0318] Condition 4: v1, v3, v5, v6 > v7 > v2, v4

[0319]

[0320] The focal lengths (F1, F4, F6) of the first, fourth, and sixth lenses (201, 204, and 206) may have positive (+) signs. The first, fourth, and sixth lenses (201, 204, and 206) may have positive (+) refractive power. The focal lengths (F2, F3, F5, and F7) of the second, third, fifth, and seventh lenses (202, 203, 205, and 207) may have negative (-) signs. The second, third, fifth, and seventh lenses (202, 203, 205, and 207) may have negative (-) refractive power. When comparing the focal lengths in absolute values, the focal length of the second lens (202) is the largest among the lenses and may be 40 or more and 60 or less. The focal length of the sixth lens (206) is the minimum among the lenses, and the absolute value of the focal length of the sixth lens (206) may be 5 or more and 8 or less.

[0321] The absolute value of the focal length of each lens can satisfy any of the conditions below.

[0322] Condition 1: |f2| > |f1| > |f3|, |f4|, |f5|, |f6|, |f7|

[0323] Condition 2: |f2| > |f1|, |f3|, |f4|, |f5|, |f6|, |f7|

[0324] Condition 3: |f1|, |f2|, |f7| > |f3| > |f4|, |f5|, |f6|

[0325] Condition 4: |f1|, |f2|, |f3|, |f7| > |f4| > |f5|, |f6|

[0326] Condition 5: |f1|, |f2|, |f3|, |f4|, |f7| > |f5| > |f6|

[0327] Condition 6: |f1|, |f2|, |f3|, |f4|, |f5|, |f7| > |f6|

[0328] Condition 7: |f1|, |f2| > |f7| > |f3|, |f4|, |f5|, |f6|

[0329]

[0330] The composite focal length (f_LG1) of the first lens group (LG1) may have a positive (+) sign. The first lens group (LG1) may have positive (+) composite refractive power. The composite focal length (f_LG2) of the second lens group (LG2) may have a negative (-) sign. The second lens group (LG2) may have negative (-) composite refractive power. The composite focal length (f_LG3) of the third lens group (LG3) may have a positive (+) sign. The third lens group (LG3) may have positive (+) composite refractive power. Through this, light incident from the object side can move away from the optical axis direction and then gather again in the optical axis direction, thereby forming a stable optical path.

[0331] When comparing the absolute values ​​of the composite focal lengths of the first to third lens groups (LG1, LG2, LG3), the composite focal length of the first lens group (LG1) may be the largest, and the composite focal length of the second lens group (LG2) may be the smallest. The relationship between the composite focal lengths of the first to third lens groups (LG1, LG2, LG3) may satisfy |f_LG1| > |f_LG3| > |f_LG2|.

[0332]

[0333] The thickness (CT1) of the first lens (201) may be at least 1 time different from the maximum thickness and the minimum thickness, for example, 1 to 1.5 times, and the center thickness (CT1) may be maximum and the edge thickness (ET1) may be minimum. The thickness (T2) of the second lens (202) may be minimum at the center and maximum at the edge, and the maximum thickness may be in the range of 1 to 1.5 times the minimum thickness. The thickness (T3) of the third lens (203) may be minimum at the center and maximum at the edge, and the maximum thickness may be in the range of 1.5 to 2 times the minimum thickness. The thickness (T4) of the fourth lens (204) may be maximum at the center and minimum at the edge, and the maximum thickness may be in the range of 1.5 to 2 times the minimum thickness. The thickness (T5) of the fifth lens (205) may be minimum at the center and maximum at the edge, and the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T6) of the sixth lens (206) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T7) of the seventh lens (207) may be minimum at the center and maximum at the edge, and the maximum thickness is in the range of 1 to 1.5 times the minimum thickness.

[0334]

[0335] The thickness of each lens can satisfy any of the conditions below.

[0336] Condition 1: 1 < CT1 / ET1 < 1.5, 0.5 < ET1 / CT1 < 1

[0337] Condition 2: 0.5 < CT2 / ET2 < 1, 1 < ET2 / CT2 < 1.5

[0338] Condition 3: 0.5 < CT3 / ET3 < 1, 1.5 < ET3 / CT3 < 2

[0339] Condition 4: 1.5 < CT4 / ET4 < 2, 0.5 < ET4 / CT4 < 1

[0340] Condition 5: 0.1 < CT5 / ET5 < 0.5, 2.5 < ET5 / CT5 < 3

[0341] Condition 6: 2.5 < CT6 / ET6 < 3, 0.1 < ET6 / CT6 < 0.5

[0342] Condition 7: 0.5 < CT7 / ET7 < 1, 1 < ET7 / CT7 < 1.5

[0343] Condition 8: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0344]

[0345] Among the gaps (G1-G6) between the lenses, the gap (LG1) between the first and second lenses (201, 202) may have a maximum in the center and a minimum at the edge. The gap (LG2) between the second and third lenses (202, 203) may have a minimum in the center and a maximum at the edge. The gap (LG3) between the third and fourth lenses (203, 204) may have a maximum in the center and a minimum at the edge. The gap (G4) between the fourth and fifth lenses (204, 205) may have a minimum in the edge and a maximum at the center. The fifth gap (G5) between the fifth and sixth lenses (205, 206) may have a minimum in the center and a maximum at the edge. The sixth gap (G6) between the sixth and seventh lenses (206, 207) may have a maximum in the center and a minimum at the edge.

[0346]

[0347] Fig. 18 is a graph showing data on aberration characteristics of an optical system according to the second embodiment operating in the first mode, Fig. 19 is a graph showing data on aberration characteristics of an optical system according to the second embodiment operating in the second mode, and Fig. 20 is a graph showing data on aberration characteristics of an optical system according to the second embodiment operating in the third mode. In the aberration graphs of Figs. 18, 19, and 20, spherical aberration (longitudinal spherical aberration), astigmatic field curves, and distortion are measured from left to right. In Figs. 18, 19, and 20, the X-axis may represent a focal length (mm) and a degree of distortion (%), and the Y-axis may represent the height of an image. In addition, the graph for spherical aberration is a graph for light in the wavelength bands of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for astigmatism and distortion is a graph for light in the wavelength band of about 546 nm. In the aberration diagrams of FIGS. 18, 19, and 20, it can be interpreted that the closer each curve is to the Y-axis, the better the aberration correction function is, and it can be seen that the optical system (1100) according to the second embodiment has measured values ​​close to the Y-axis in almost all areas. That is, the optical system (1100) according to the second embodiment has improved resolution and can have good optical performance not only in the center of the field of view (FOV) but also in the periphery.

[0348]

[0349] The optical systems (1000, 1100) according to the first and second embodiments disclosed above can satisfy at least one or two or more of the mathematical equations described below. Accordingly, the optical systems (1000, 1100) according to the first and second embodiments can have improved optical characteristics. For example, when the optical system (1000, 1100) satisfies at least one mathematical equation, the optical system (1000, 1100) can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only at the center but also at the periphery of the field of view (FOV). In addition, the optical system (1000, 1100) can have improved resolution. In addition, the thickness of the lens on the optical axis (OA) and the spacing of adjacent lenses on the optical axis (OA) described in the mathematical equations may refer to the first and second embodiments disclosed above.

[0350]

[0351] [Mathematical Formula 1]

[0352] 0.5 < TD_LG2 / TD_LG3 < 1

[0353] Mathematical expression 1 can establish the relationship between the length (TD_LG2) of the second lens group (LG2) and the length (TD_LG3) of the third lens group (LG3) in the optical axis direction. Mathematical expression 1 is a condition for reducing aberration and improving optical performance.

[0354] The second lens group (LG2) and the third lens group (LG3) satisfying mathematical expression 1 can appropriately correct astigmatism and coma aberration. In addition, the overall length of the zoom optical system having an appropriate zoom ratio can be reduced. In the first and second embodiments, mathematical expression 1 can preferably satisfy 0.8 < TD_LG2 / TD_LG3 < 1.

[0355]

[0356] [Equation 2]

[0357] 10 < EFL(F)_wide < 20

[0358] In mathematical expression 2, EFL(F)_wide is the total focal length of the optical system (1000, 1100) at the wide-angle end. Mathematical expression 2 is a condition for limiting zoom optical performance. If the upper limit of mathematical expression 2 is exceeded, it is difficult to secure optical performance due to chromatic aberration, and the amount of movement of each lens group increases significantly during zooming, making mechanical miniaturization difficult. If it is less than the lower limit of mathematical expression 2, there is a problem that the sensitivity of the entire optical system increases. A zoom optical system satisfying mathematical expression 2 can secure practically useful optical performance. Mathematical expression 2 can preferably satisfy 15 < EFL(F)_wide < 18 in the first and second embodiments.

[0359]

[0360] [Equation 3]

[0361] 10 < BFL_wide < 20

[0362] In mathematical expression 3, BFL_wide is the optical axis distance from the wide-angle end to the center of the sensor side of the last lens in the image sensor (300). When mathematical expression 3 is satisfied, the installation space of the filter (400) and the cover glass can be secured, and the assemblability of the components can be improved through the gap between the image sensor (300) and the last lens, and the joint reliability can be improved. In the first and second embodiments, mathematical expression 3 can preferably satisfy 15 < BFL_wide < 18. When BFL_wide is less than the range of mathematical expression 3, some of the light traveling to the image sensor may not be transmitted to the image sensor, which may cause a decrease in resolution. When BFL_wide exceeds the range of mathematical expression 3, stray light may be introduced, which may deteriorate the aberration characteristics of the optical system.

[0363]

[0364] [Equation 4]

[0365] 20 < Ave_ABV < 40

[0366] In mathematical expression 4, Ave_ABV is the average of the Abbe numbers of the lenses included in the optical system (1000, 1100). When mathematical expression 4 is satisfied, optical performance can be improved by appropriately setting factors affecting chromatic aberration. In the first and second embodiments, mathematical expression 4 can preferably satisfy 35 < Ave_ABV < 40.

[0367]

[0368] [Equation 5]

[0369] 1.5 < Ave_Ind < 1.7

[0370] In mathematical expression 5, Ave_Ind is the average of the refractive indices of the lenses included in the optical system (1000, 1100). When mathematical expression 5 is satisfied, optical performance can be improved by appropriately setting factors affecting chromatic aberration. In the first and second embodiments, mathematical expression 4 can preferably satisfy 1.6 < Ave_Ind < 1.65.

[0371]

[0372] [Equation 6]

[0373] 0.5 < |f_LG2 / f_LG3| < 1

[0374] Mathematical expression 6 can set the relationship between the focal length (f_LG2) of the second lens group (LG2) and the focal length (f_LG3) of the third lens group (LG3). Mathematical expression 6 is a condition for reducing aberration and improving optical performance. The second lens group (LG2) and the third lens group (LG3) that satisfy Mathematical expression 6 can appropriately correct astigmatism and coma. Mathematical expression 6 can preferably satisfy 0.6 < |f_LG2 / f_LG3| < 0.8 in the first and second embodiments.

[0375]

[0376] [Equation 7]

[0377] 8 < |f_LG3| < 15

[0378] In mathematical expression 7, f_LG3 is the focal length of the third lens group (LG3). Mathematical expression 7 is a condition for reducing aberration and improving optical performance. Mathematical expression 7 can preferably satisfy 9 < |f_LG3| < 11 in the first and second embodiments.

[0379]

[0380] [Equation 8]

[0381] 5 < LG2_stroke < 10

[0382] Mathematical expression 8 can set the range of the stroke length (LG2_stroke) of the second lens group (LG2). If it exceeds the upper limit of Mathematical expression 8, the stroke length of the second lens group (LG2) increases during focusing, making it difficult to miniaturize the optical system. If it is less than the lower limit of Mathematical expression 8, the focusing performance of the optical system may deteriorate. Mathematical expression 8 can preferably satisfy 5 < LG2_stroke < 7 in the first and second embodiments.

[0383]

[0384] [Equation 9]

[0385] 10 < F1 < 30

[0386] In mathematical expression 9, F1 is the focal length of the first lens (101, 201). When mathematical expression 9 is satisfied, the optical system (1000, 1100) can have a set angle of view and an appropriate focal length, and can set the angle of view to be large within an appropriate TTL range. When it is less than the lower limit of mathematical expression 9, the effective diameter or TTL of the lenses may become long, which may cause a problem in that the imaging lens system becomes large. When it is more than the upper limit of mathematical expression 9, the influence of the first lens (101, 201) in the entire optical system becomes small, and the refractive power of the lenses needs to be increased, which causes a problem in that it is difficult to correct spherical aberration or distortion aberration. In the first and second embodiments, mathematical expression 9 may preferably satisfy 12 < F1 < 18.

[0387]

[0388] [Equation 10]

[0389] 1 < CT1 < 5

[0390] In mathematical expression 10, CT1 is the central thickness of the first lens (101, 201). When mathematical expression 10 is satisfied, the thickness of the optical system (1000, 1100) in the first direction (y-axis direction) can be prevented from increasing, and a miniaturized optical system can be implemented. In the first and second embodiments, mathematical expression 10 can preferably satisfy 2 < CT1 < 3.

[0391]

[0392] [Equation 11]

[0393] 20 < TTL < 50

[0394] In mathematical expression 11, TTL (Total track length) means the distance (mm) from the center of the first surface (S1) of the first lens (101, 201) to the upper surface of the image sensor (300) on the optical axis (OA). In the first and second embodiments, mathematical expression 11 can preferably satisfy 35 < TTL < 40.

[0395]

[0396] [Equation 12]

[0397] 5 < ImgH < 8

[0398] In mathematical expression 12, ImgH represents the maximum diagonal length of the image sensor (300). Mathematical expression 12 can set the diagonal size (ImgH) of the image sensor (300) and provide an optical system having a large mobile image sensor size. In the first and second embodiments, mathematical expression 12 can preferably satisfy 6 < ImgH < 7.

[0399]

[0400] [Equation 13]

[0401] 2 < Fno_wide < 5

[0402] Mathematical expression 13 can set the range of Fno_wide of the optical system (1000, 1100). When mathematical expression 13 is satisfied, an image with an appropriate brightness can be provided, and a large amount of light can be received by the image sensor. In the first and second embodiments, mathematical expression 13 can preferably satisfy 2.5 < Fno_wide < 3.5.

[0403]

[0404] [Equation 14]

[0405] 10 < FOV_wide < 30

[0406] In mathematical expression 14, the range of the angle of view (FOV_wide) at the wide-angle end can be set. In mathematical expression 14, an angle of view suitable for a mobile optical system can be provided. In the first and second embodiments, FOV_wide can preferably satisfy 20 < FOV_wide < 25.

[0407]

[0408] [Equation 15]

[0409] 3 < TTL / CA_max < 7

[0410] In mathematical expression 15, CA_max means the largest effective diameter (mm) among the object-side and sensor-side of a plurality of lenses, and TTL (Total track length) means the distance (mm) from the vertex of the first surface (S1) of the first lens (101, 201) to the upper surface of the image sensor (300) on the optical axis (OA). Mathematical expression 15 sets the relationship between the total optical axis length of the optical system and the maximum effective diameter, thereby providing an improved mobile optical system. In the first and second embodiments, mathematical expression 15 can preferably satisfy 4 < TTL / CA_max < 5.5.

[0411]

[0412] [Equation 16]

[0413] 3 < TTL / ImgH < 8

[0414] In mathematical expression 16, TTL (Total track length) means the distance (mm) from the vertex of the first surface (S1) of the first lens to the upper surface of the image sensor (300) on the optical axis (OA), and ImgH means the maximum diagonal length of the image sensor (300). When mathematical expression 16 is satisfied, the optical system (1000, 1100) can have TTL for application to the mobile image sensor (300), thereby providing improved image quality. When it is less than the lower limit of mathematical expression 2, the refractive power of the lenses needs to be increased, making it difficult to correct spherical aberration or distortion aberration, and when it is more than the upper limit of mathematical expression 2, the effective diameter or TTL of the lenses becomes long, which may cause a problem of the imaging lens system becoming larger. In the first and second embodiments, mathematical expression 16 can preferably satisfy 5.5 < TTL / ImgH < 6.5.

[0415]

[0416] [Equation 17]

[0417] 1 < EFL(F)_wide / ImgH < 4

[0418] In mathematical expression 17, EFL(F)_wide is the total effective focal length of the optical system (1000, 1100) at the wide-angle end, and ImgH means the maximum diagonal length of the image sensor (300). When mathematical expression 17 is satisfied, the mobile image sensor (300) can have improved aberration characteristics in its size. In the first and second embodiments, mathematical expression 17 can preferably satisfy 2 < EFL(F)_wide / ImgH < 3.

[0419]

[0420] [Equation 18]

[0421] 0.1 < ΣCT / TTL < 1

[0422] Mathematical expression 18 can set the relationship between the sum of the central thicknesses of the lenses (ΣCT) and the distance (TTL) from the vertex of the first surface (S1) of the first lens to the upper surface of the image sensor (300) on the optical axis (OA). If the upper limit of Mathematical expression 18 is exceeded, the number of lenses increases and the movement of the movable lens group in the optical system may become unfavorable. If the lower limit of Mathematical expression 18 is less than the lower limit of Mathematical expression 18, the focusing performance of the optical system may deteriorate. In the first and second embodiments, Mathematical expression 18 can preferably satisfy 0.2 < ΣCT / TTL < 0.5.

[0423]

[0424] [Equation 19]

[0425] 0.1 < ΣCG / TTL < 1

[0426] Mathematical expression 19 can set the relationship between the sum of the spacings between adjacent lenses (ΣCG) and the distance (TTL) from the vertex of the first surface (S1) of the first lens to the upper surface of the image sensor (300) on the optical axis (OA). If the upper limit of Mathematical expression 19 is exceeded, the moving distance of the moving lens group in the lens optical system increases, which may increase the current consumption during focusing operation. If the lower limit of Mathematical expression 19 is less than the lower limit of Mathematical expression 19, the focusing performance of the optical system may deteriorate. In the first and second embodiments, Mathematical expression 19 can preferably satisfy 0.1 < ΣCG / TTL < 0.5.

[0427]

[0428] [Equation 20]

[0429] 1 < ΣCT / ΣCG < 5

[0430] Mathematical expression 20 can set the relationship between the sum of the central thicknesses of the lenses (ΣCT) and the sum of the spacings between adjacent lenses (ΣCT). If the upper limit of Mathematical expression 20 is exceeded, the number of lenses increases and the movement of the movable lens group in the optical system may become unfavorable. If the lower limit of Mathematical expression 20 is less than the lower limit of Mathematical expression 20, the focusing performance may deteriorate. In the first and second embodiments, Mathematical expression 20 can preferably satisfy 1 < ΣCT / ΣCG < 2.

[0431]

[0432] [Equation 21]

[0433] 1 < CA_max / CA_min < 3

[0434] In mathematical expression 21, CA_max represents the maximum effective diameter among the object-side and sensor-side surfaces of the lenses, and CA_min represents the minimum effective diameter among the object-side and sensor-side surfaces of the lenses. When mathematical expression 21 is satisfied, the optical system can set a size for a slim and compact structure while maintaining optical performance. In the first and second embodiments, mathematical expression 21 can preferably satisfy 1 < CA_max / CA_min < 1.8.

[0435]

[0436] [Equation 22]

[0437] 1 < CA_max / ImgH < 5

[0438] In mathematical expression 22, CA_max represents the maximum effective diameter among the object-side and sensor-side surfaces of the lenses, and ImgH represents the maximum diagonal length of the image sensor (300). When mathematical expression 22 is satisfied, the optical system can maintain good optical performance and set a size for a slim and compact structure. In the first and second embodiments, mathematical expression 22 can preferably satisfy 1 < CA_max / ImgH < 1.5.

[0439]

[0440] [Equation 23]

[0441] 0.1 < CA_min / ImgH < 1

[0442] In mathematical expression 23, CA_min represents the minimum effective diameter among the object-side and sensor-side surfaces of the lenses, and ImgH represents the maximum diagonal length of the image sensor (300). When mathematical expression 23 is satisfied, the optical system can maintain good optical performance and set a size for a slim and compact structure. In the first and second embodiments, mathematical expression 23 can preferably satisfy 0.5 < CA_min / ImgH < 1.

[0443]

[0444] [Equation 24]

[0445] 25 < L1R1+L6R1 < 35

[0446] In mathematical expression 24, L1R1 is the radius of curvature of the object-side surface of the first lens (101, 201) arranged closest to the object-side surface of the first lens group (LG1), and L6R1 is the radius of curvature of the object-side surface of the sixth lens (106, 206) arranged closest to the object-side surface of the third lens group (LG3). When mathematical expression 24 is satisfied, the optical system (1000, 1100) can have a set angle of view and an appropriate focal length, and can set the angle of view to be large within an appropriate TTL range. When it is less than the lower limit of mathematical expression 24, the effective diameter or TTL of the lenses may become long, which may cause a problem in that the imaging lens system becomes large. When it is more than the upper limit of mathematical expression 24, the refractive power of the lenses needs to be increased, which makes it difficult to correct spherical aberration or distortion aberration. In the first and second embodiments, mathematical expression 24 can preferably satisfy 28 < L1R1+L6R1 < 35.

[0447]

[0448] [Equation 25]

[0449] 0.3 < BFL / TTL < 0.5

[0450] In mathematical expression 25, BFL is the optical axis distance from the image sensor (300) to the center of the sensor side of the last lens, and TTL (Total track length) means the distance (mm) on the optical axis (OA) from the vertex of the first surface (S1) of the first lens (101, 201) to the upper surface of the image sensor (300). When mathematical expression 25 is satisfied, the space for arranging the optical path control member within the optical system (1000, 1100) can be secured, thereby miniaturizing the size of the entire optical system. When it is less than the lower limit of mathematical expression 25, there is a problem of interference occurring between the mirror and the image sensor, and when it is more than the upper limit of mathematical expression 25, there is a problem of the optical system becoming large. In the first and second embodiments, mathematical expression 25 can preferably satisfy 0.4 < BFL / TTL < 0.5.

[0451]

[0452] [Equation 26]

[0453]

[0454] In mathematical expression 26, Z can represent Sag, which is the distance from any position on the aspherical surface to the vertex of the aspherical surface along the optical axis. Y can represent the distance from any position on the aspherical surface to the optical axis in the direction perpendicular to the optical axis. c can represent the curvature of the lens, and K can represent the conic constant. In addition, A, B, C, D, E, and F can represent aspheric constants.

[0455]

[0456] The optical system (1000, 1100) according to the first and second embodiments can satisfy at least one or two or more mathematical expressions from mathematical expressions 1 to 26. In this case, the optical system (1000, 1100) can have improved optical characteristics. Specifically, when the optical system (1000, 1100) satisfies at least one or two or more mathematical expressions from mathematical expressions 1 to 26, the optical system (1000, 1100) can have improved resolution and improve aberration and distortion characteristics. In addition, the optical system (1000, 1100) can secure a BFL (Back focal length) for applying the image sensor (260), can compensate for optical characteristic degradation due to temperature change, and can minimize the gap between the last lens and the image sensor (260), thereby having good optical performance at the center and periphery of the field of view (FOV).

[0457]

[0458] 수학식제1실시예제2실시예10.5 < TD_LG2 / TD_LG3 < 10.9610.923210 < EFL(F)_wide < 2015.93015.930310 < BFL_wide < 2016.40015.770420 < Ave_ABV < 4035.88635.88651.5 < Ave_Ind < 1.71.6101.61060.5 < |f_LG2 / f_LG3| < 10.7770.77978 < |f_LG3| < 1510.73010.34085 < LG2_stroke < 106.2105.970910 < F1 < 3014.87015.470101 < CT1 < 52.1002.3401120 < TTL < 5038.41037.800125 < ImgH < 86.6006.300132 < Fno_wide < 53.3002.9001410 < FOV_wide < 3023.50022.200153 < TTL / CA_max < 74.0455.164163 < TTL / ImgH < 85.8206.000171 < EFL(F)_wide / ImgH < 42.4142.529180.1 < ΣCT / TTL < 10.2940.312190.1 < ΣCG / TTL < 10.2790.271201 < ΣCT / ΣCG < 51.0521.152211 < CA_max / CA_min < 31.6361.183221 < CA_max / ImgH < 51.4391.162230.1 < CA_min / ImgH < 10.8800.9832425 < L1R1+L6R1 < 3529.24034.050250.3 < BFL / TTL < 0.50.4260.417

[0459] Table 7 shows the result values ​​for the mathematical expressions 1 to 26 described above in the optical systems (1000, 1100) of the first and second embodiments. Referring to Table 7, it can be seen that the optical systems (1000, 1100) satisfy at least one, two or more, or three or more of the mathematical expressions 1 to 26. In detail, it can be seen that the optical systems (1000, 1100) according to the first and second embodiments satisfy all of the mathematical expressions 1 to 26. Accordingly, the optical systems (1000, 1100) can have good optical performance and excellent optical characteristics at the center and periphery of the field of view (FOV).

[0460]

[0461] Fig. 22 is an example of a mobile terminal having an optical system according to the present embodiment. As illustrated in Fig. 22, the mobile terminal (1500) may include a camera module (1520), a flash module (1530), and an autofocus device (1510) provided on one side or the rear side. Here, the autofocus device (1510) may include the surface-emitting laser element disclosed above as a light-emitting layer and a light receiving unit.

[0462] The flash module (1530) may include an emitter that emits light within it. The flash module (1530) may be operated by the camera of the mobile terminal or under user control. The camera module (1520) may include an image capturing function and an autofocus function. For example, the camera module (1520) may include an autofocus function using an image.

[0463] The autofocus device (1510) may include an autofocus function using a laser. The autofocus device (1510) may be primarily used in conditions where the autofocus function using the image of the camera module (1520) is degraded. In addition, although not shown in the drawing, at least one camera module may be additionally positioned on the front of the mobile terminal (1500). At least one of the camera modules within the mobile terminal may have a tele-type folded optical system as disclosed above.

[0464] The optical system or camera module according to the embodiment of the invention, the lens assembly according to various embodiments, can be applied to, for example, an electronic device employing an image sensor. The lens assembly according to the exemplary embodiment can be applied to various electronic devices such as a digital camera, an interchangeable lens camera, a video camera, a mobile phone camera, a camera for a small mobile device, a VR, an AR, a drone, or a manned / unmanned aerial vehicle.

[0465] The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiments pertain. Therefore, the contents related to such combinations and modifications should be construed as falling within the scope of the present invention.

[0466] In addition, although the above description focuses on examples, these are merely examples and do not limit the present invention. Those skilled in the art to which the present invention pertains will appreciate that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the present invention. For example, each component specifically shown in the examples can be modified and implemented. In addition, differences related to such modifications and applications should be interpreted as being included within the scope of the present invention defined in the appended claims.

Claims

1. Including first to third lens groups arranged along the optical axis, The above first lens group has positive (+) refractive power, The above second lens group has a negative (-) refractive power, The above third lens group has positive (+) refractive power, An optical system wherein the first to third lens groups include at least one lens having negative (-) refractive power.

2. In paragraph 1, The first and second lens groups are moving groups, The above third lens group is a fixed group optical system.

3. In paragraph 1, The object-side surface of the lens placed on the most object-side of the first lens group on the optical axis has a convex shape, An optical system in which the object-side surface of the lens arranged on the most object-side of the third lens group on the optical axis has a convex shape.

4. In paragraph 1, When the above optical system operates from a wide-angle end to a telephoto end, An optical system in which the distance between the first lens group and the second lens group increases, and the distance between the second lens group and the third lens group decreases.

5. In paragraph 1, An optical system in which the stroke length of the second lens group is longer than the stroke length of the first lens group when the optical system operates from the wide-angle end to the telephoto end.

6. In paragraph 1, The above first lens group includes a first lens and a second lens, The second lens group includes a third lens, a fourth lens, and a fifth lens, The third lens group is an optical system including a sixth lens and a seventh lens.

7. In paragraph 6, The above first lens has positive (+) refractive power, The above second lens has negative (-) refractive power, The above third lens has a negative (-) refractive power, The above fourth lens has positive (+) refractive power, The above fifth lens has a negative (-) refractive power, The above sixth lens has positive (+) refractive power, The above seventh lens is an optical system having negative (-) refractive power.

8. In paragraph 1, A first optical path control member is arranged on the object side of the first lens group, An optical system in which a second optical path control member is positioned between the third lens group and the image sensor.

9. In paragraph 8, The above first optical path control member is a prism lens, The above second optical path control member is an optical system that is a mirror.

10. Including first to seventh lenses arranged along the optical axis, The above first lens has positive (+) refractive power, The above second lens has negative (-) refractive power, The above third lens has a negative (-) refractive power, The above fourth lens has positive (+) refractive power, The above fifth lens has a negative (-) refractive power, The above sixth lens has positive (+) refractive power, The above seventh lens has a negative (-) refractive power, The above first lens and the above second lens are a first lens group, which is a moving group, The third lens, the fourth lens and the fifth lens are a second lens group, which is a moving group. The optical system in which the sixth lens and the seventh lens are the third lens group, which is a fixed group.

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