Optical system and camera module

Abstract

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

Description

Technical Field

[0001] The teachings of exemplary and non-limiting embodiments of this disclosure generally relate to an optical system for improving optical performance and a camera module including the optical system. Background Technology

[0002] Camera modules perform the function of capturing objects and storing them as images or videos, and are installed in a variety of applications. In particular, camera modules are manufactured in an ultra-compact size and are used not only in portable devices such as smartphones, tablet PCs, and laptops, but also in drones and vehicles, thus providing a wide range of functions.

[0003] For example, the optical system of a camera module may include an imaging lens for forming an image and an image sensor for converting the formed image into an electrical signal. In this case, the camera module can perform an autofocus (AF) function by automatically adjusting the distance between the image sensor and the imaging lens to align the lens's focal length, and can perform a zoom function by increasing or decreasing the magnification of a distant object using a zoom lens. Furthermore, the camera module employs image stabilization (IS) technology to correct or prevent image blur caused by unstable mounting or camera movement due to user motion.

[0004] The most important component of a camera module for acquiring images is the imaging lens that forms the image. Recently, there has been increasing interest in high performance, such as high image quality and high resolution, and research is underway on optical systems that include multiple lenses to achieve this.

[0005] For example, research is underway to realize high-performance optical systems using multiple imaging lenses with positive (+) or negative (-) refractive power. Optical systems incorporating multiple lenses can have a set effective focal length (EFL). In this case, when the EFL value is relatively large, the lens closest to the object side has a large aperture or the largest aperture among the multiple lenses. Therefore, the lens closest to the object side has a relatively large size, making it difficult to miniaturize the optical system.

[0006] Optical systems that include multiple lenses can have a relatively large height. For example, as the number of lenses increases, the distance from the image sensor to the object plane of the lens of a neighboring object can increase. Therefore, the overall thickness of the device in which the optical system is arranged (such as a smartphone) can increase, and there is a problem of difficulty in miniaturization.

[0007] Near-field imaging camera modules typically have a shorter TTL compared to conventional camera modules. Another example is that long-range imaging camera modules have a longer TTL compared to conventional camera modules. However, portable devices have limited space for camera modules, making it difficult to incorporate long-range imaging camera modules or camera modules capable of adjusting image magnification (zoom camera modules). Therefore, new optical systems are needed to address these issues. Summary of the Invention

[0008] Technical Purpose

[0009] This exemplary embodiment aims to provide an optical system with improved optical properties and a camera module.

[0010] This exemplary embodiment is also intended to provide an optical system that can be implemented in a small and compact manner.

[0011] Furthermore, this exemplary embodiment aims to provide an optical system in which at least one lens adjacent to the object side of the terminal or adjacent to the outer side of the terminal has different lengths along a first direction and a second direction. In other words, an optical system can be provided in which at least one or more lenses have different lengths along two mutually orthogonal axial directions.

[0012] Furthermore, this disclosure aims to provide an optical system applicable to folding cameras or macro modes having a thin thickness or height.

[0013] Technical solution

[0014] To address the aforementioned technical issues, an optical system according to an exemplary embodiment of this disclosure may include a first lens group to a fourth lens group arranged along an optical axis, wherein the first lens group has positive (+) refractive power, the second lens group has positive (+) refractive power, the third lens group has negative (-) refractive power, the fourth lens group has positive (+) refractive power, and the first lens group to the fourth lens group includes at least one lens having negative (-) refractive power.

[0015] Preferably, but not necessarily, the first to third lens groups can be movable groups, and the fourth lens group can be a fixed group.

[0016] Preferably, but not necessarily, the object-side surface of the lens disposed closest to the object side of the first lens group on the optical axis may have a convex shape, and the object-side surface of the lens disposed closest to the object side of the fourth lens group on the optical axis may also have a convex shape.

[0017] Preferably, but not necessarily, when the optical system is operated from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group can be increased, the distance between the second lens group and the third lens group can be increased, and the distance between the third lens group and the fourth lens group can be decreased.

[0018] Preferably, but not necessarily, when the optical system is operated from the wide-angle end to the telephoto end, the travel length of the third lens group can be greater than the travel length of the first lens group and can be greater than the travel length of the second lens group.

[0019] Preferably, but not necessarily, the first lens group may include a first lens and a second lens, the second lens group may include a third lens and a fourth lens, the third lens group may include a fifth lens having negative (-) refractive power, and the fourth lens group may include a sixth lens and a seventh lens.

[0020] Preferably, but not necessarily, 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 sixth lens may have positive (+) refractive power, and the seventh lens may have negative (-) refractive power.

[0021] Preferably, but not necessarily, the first optical path control component can be disposed on the object side of the first lens group, and the second optical path control component can be disposed between the fourth lens group and the image sensor.

[0022] Preferably, but not necessarily, the first optical path control component can be a prism lens, and the second optical path control component can be a mirror.

[0023] To address the aforementioned technical issues, an optical system according to another exemplary embodiment of this disclosure may include a first lens to a seventh lens 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. The first and second lenses may form a movable first lens group, and the third and fourth lenses may form a movable second lens group. The fifth lens may be a movable third lens group, and the sixth and seventh lenses may be a fixed fourth lens group.

[0024] Preferably, but not necessarily, the first lens group may have positive (+) refractive power, the second lens group may have positive (+) refractive power, the third lens group may have negative (-) refractive power, and the fourth lens group may have positive (+) refractive power.

[0025] Preferably, but not necessarily, the object-side surface of the first lens may have a convex shape on the optical axis, and the object-side surface of the sixth lens may have a convex shape on the optical axis.

[0026] Preferably, but not necessarily, when the optical system is operated from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group can be increased, the distance between the second lens group and the third lens group can be increased, and the distance between the third lens group and the fourth lens group can be decreased.

[0027] Preferably, but not necessarily, when the optical system is operated from the wide-angle end to the telephoto end, the travel length of the third lens group can be greater than the travel length of the first lens group and can be greater than the travel length of the second lens group.

[0028] Preferably, but not necessarily, the optical system can meet the following conditions.

[0029] <Conditions>

[0030] 0.2 < BFL / TTL < 0.5

[0031] Under the above conditions, BFL is the optical axis distance from the center of the image sensor to the sensor side 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.

[0032] Technical effect

[0033] The optical system and camera module according to this exemplary embodiment can have various magnifications and can provide excellent optical characteristics when various magnifications are provided. In detail, this embodiment controls a lens group with a set number of lenses having refractive power, multiple lenses having a set shape and focal length, and the movement distance of the lens group to achieve various magnifications and provide autofocus (AF) functionality for the object.

[0034] Furthermore, each lens group can correct aberration characteristics or mutually compensate for aberration characteristics that change due to motion. As a result, the optical system according to this embodiment can minimize or prevent changes in chromatic aberration and aberration characteristics that occur during magnification changes.

[0035] Furthermore, the optical system and camera module according to the embodiments can control the effective focal length (EFL) by moving only some of the plurality of lens groups, and minimize the movement distance of the moving lens groups. Therefore, the embodiments significantly reduce the movement distance of the lens groups during magnification changes and minimize the power consumption required during lens group movement.

[0036] Furthermore, the optical system according to this embodiment has improved optical characteristics and can have a large BFL (back focal length), thereby providing an optical system suitable for folding camera modules. Attached Figure Description

[0037] Figure 1 This is a configuration diagram of the optical system operating in a first mode according to a first exemplary embodiment.

[0038] Figure 2 This is a modular configuration diagram of the optical system according to the first embodiment operating in a first mode.

[0039] Figure 3 This is a configuration diagram of the optical system according to the first embodiment operating in a second mode.

[0040] Figure 4 This is a modular configuration diagram of the optical system according to the first embodiment operating in a second mode.

[0041] Figure 5 This is a configuration diagram of the optical system according to the first embodiment operating in the third mode.

[0042] Figure 6 This is a modular configuration diagram of the optical system according to the first embodiment operating in a third mode.

[0043] Figure 7 This is a table showing the aspherical coefficients of the lenses in the optical system according to the first embodiment.

[0044] Figure 8 It is a graph showing the aberration characteristics of the optical system according to the first embodiment operating in a first mode.

[0045] Figure 9 It is a graph showing the aberration characteristics of the optical system according to the first embodiment operating in the second mode.

[0046] Figure 10 It is a graph showing the aberration characteristics of the optical system according to the first embodiment operating in the third mode.

[0047] Figure 11 This is a configuration diagram of an optical system operating in a first mode according to a second exemplary embodiment.

[0048] Figure 12 This is a modular configuration diagram of an optical system operating in a first mode according to the second embodiment.

[0049] Figure 13 This is a configuration diagram of an optical system operating in a second mode according to the second embodiment.

[0050] Figure 14 This is a modular configuration diagram of an optical system operating in a second mode according to the second embodiment.

[0051] Figure 15 This is a configuration diagram of an optical system operating in a third mode according to the second embodiment.

[0052] Figure 16 This is a modular configuration diagram of an optical system operating in a third mode according to the second embodiment.

[0053] Figure 17 This is a table showing the aspherical coefficients of the lenses in the optical system according to the second embodiment.

[0054] Figure 18 It is a graph showing the aberration characteristics of the optical system operating in the first mode according to the second embodiment.

[0055] Figure 19 It is a graph showing the aberration characteristics of the optical system operating in the second mode according to the second embodiment.

[0056] Figure 20 It is a graph showing the aberration characteristics of the optical system operating in the third mode according to the second embodiment.

[0057] Figure 21 This is a diagram illustrating the D-shaped cut lens of this disclosure.

[0058] Figure 22 This is an example of a mobile terminal having an optical system according to this exemplary embodiment. Detailed Implementation

[0059] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0060] However, this disclosure is not limited to the given exemplary embodiments described, but can be implemented in various different forms, and one or more components in the exemplary embodiments can be optionally combined or substituted among the embodiments within the scope of this disclosure.

[0061] Furthermore, unless explicitly defined and described, the terms (including technical and scientific terms) used in the embodiments of this disclosure may be interpreted in the meaning understood by one of ordinary skill in the art to which this disclosure pertains, and common terms (such as terms defined in a dictionary) will be interpreted according to their meaning in the context of the relevant field.

[0062] Furthermore, the terminology used in the embodiments of this disclosure is intended to describe these embodiments and is not intended to limit the disclosure.

[0063] In this specification, unless the context otherwise requires, the singular form may also include the plural form, and references to “at least one (or more) of A and / or B and C” may include one or more combinations of any combination of A, B and C.

[0064] Furthermore, the terms first, second, A, B, (a), (b), etc., can be used to describe components of embodiments of this disclosure. Such terms are intended only to distinguish one component from another, and are not intended to limit the nature, order, or sequence of these components.

[0065] Furthermore, when describing a component as being “connected,” “joined,” or “attached” to another component, the description may include not only direct connection, joining, or attachment to another component, but also cases where the component is “connected,” “joined,” or “attached” to another component between the component and other components.

[0066] Furthermore, when described as being formed or disposed "above" or "below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or disposed between the two components. Additionally, when expressed as "above" or "below," it can include both upward and downward meanings relative to a single component.

[0067] In the description of this disclosure, "object-side surface" can refer to the surface of a lens facing the object side relative to the optical axis (OA), and "sensor-side surface" can refer to the surface of a lens facing the imaging surface (image sensor) relative to the optical axis. "Object-side surface" can be referred to as "object surface," and "sensor-side surface" can be referred to as "image surface." A convex surface of a lens can refer to a convex shape on or near the optical axis, and a concave surface of a lens can refer to a concave shape on or near the optical axis. Values ​​listed in the table for lens data (such as radius of curvature, center thickness, and optical axis spacing between lenses) can refer to values ​​measured along the optical axis (in mm). "Vertical direction" can refer to a direction perpendicular to the optical axis, and "end of lens" or "lens surface" can refer to the end of the effective area of ​​the lens through which incident light passes. The effective diameter of the lens surface can have a measurement error of up to ±0.4 mm, depending on the measurement method. The term "paraxial region" refers to a very narrow region near the optical axis where the distance from the optical axis (OA) to the incident light is almost zero. In the following text, the term "optical axis" may refer to the center of each lens or a very narrow area near the optical axis.

[0068] The optical axis (OA) can refer to the central axis of the path along which light incident from the second direction (Y-axis direction) is refracted by the prism lens to the first direction (X-axis direction).

[0069] The optical systems (1000, 1100) according to the first and second embodiments may include multiple lens groups. More specifically, the optical systems (1000, 1100) may include multiple lens groups, each including at least one lens. For example, the optical systems (1000, 1100) may include a first lens group (LG1), a second lens group (LG2), a third lens group (LG3), a fourth lens group (LG4), and an image sensor (300) arranged sequentially along the direction from the object side to the image sensor.

[0070] The first to fourth lens groups (LG1, LG2, LG3, LG4) can each have positive (+) or negative (-) refractive power. The first lens group (LG1) and the second lens group (LG2) can have refractive power of the same sign. For example, the first lens group (LG1) can have positive (+) refractive power, and the second lens group (LG2) can also have positive (+) refractive power. The third lens group (LG3) can have negative (-) refractive power. Furthermore, the fourth lens group (LG4) can have positive (+) refractive power.

[0071] The first to fourth lens groups (LG1, LG2, LG3, LG4) may include at least one lens with negative (-) refractive power. This allows for the appropriate distribution of refractive power within each lens group, thereby guiding incident light precisely into the image sensor. Specifically, the second lens (101, 202) included in the first lens group (LG1) has negative (-) refractive power, the third lens (103, 203) included in the second lens group (LG2) has negative (-) refractive power, the fifth lens (105, 205) included in the third lens group (LG3) has negative (-) refractive power, and the seventh lens (107, 207) included in the fourth lens group (LG4) may have negative (-) refractive power.

[0072] At least one of the first lens group (LG1), the second lens group (LG2), the third lens group (LG3), and the fourth lens group (LG4) can be configured to be movable along the optical axis (OA). For example, the first lens group (LG1), the second lens group (LG2), and the third lens group (LG3) can be movably arranged, and the fourth lens group (LG4) can be fixed. The fourth lens group (LG4) can be positioned at a fixed location, and the first lens group (LG1), the second lens group (LG2), and the third lens group (LG3) can be configured to be movable along the optical axis (OA).

[0073] The first lens group (LG1) may include multiple lenses. More specifically, the first lens group (LG1) may include two or more lenses with opposite refractive powers. For example, the first lens group (LG1) may include two lenses.

[0074] The multiple lenses included in the first lens group (LG1) can have a set spacing. More specifically, in the operating mode described below, the spacing between the multiple lenses included in the first lens group (LG1) can remain constant and unchanged. For example, the spacing between the first lens (101, 201) and the second lens (102, 202) can remain constant and unchanged in the operating mode described below.

[0075] The second lens group (LG2) may include multiple lenses. More specifically, the second lens group (LG2) may include two or more lenses with opposite refractive powers. The number of lenses included in the second lens group (LG2) may be the same as the number of lenses included in the first lens group (LG1). For example, the second lens group (LG2) may include two lenses.

[0076] Multiple lenses included in the second lens group (LG2) can have a set spacing. More specifically, in the operating mode described below, the spacing between the multiple lenses included in the second lens group (LG2) can remain constant and unchanged. For example, the spacing between the third lens (103, 203) and the fourth lens (104, 204) can remain constant and unchanged in the operating mode described below.

[0077] The third lens group (LG3) may include a single lens. The number of lenses included in the third lens group (LG3) may be less than the number of lenses included in the second lens group (LG2). For example, the third lens group (LG3) may include one lens. The third lens group (LG3) may include a fifth lens (105, 205).

[0078] The fourth lens group (LG4) may include multiple lenses. More specifically, the fourth lens group (LG4) may include two or more lenses with opposite refractive powers. For example, the fourth lens group (LG4) may include two lenses.

[0079] The multiple lenses included in the fourth lens group (LG4) can have a set spacing. More specifically, in the operating mode described below, the spacing between the multiple lenses included in the fourth lens group (LG4) can remain constant and unchanged. For example, the spacing between the sixth lens (106, 206) and the seventh lens (107, 207) can remain constant and unchanged in the operating mode described below.

[0080] The optical system (1000, 1100) may include a plurality of lens groups (LG1, LG2, LG3, LG4) arranged sequentially from the object side toward the sensor side and an image sensor (300). Furthermore, the optical system (1000, 1100) may include a plurality of lenses contained within the lens groups (LG1, LG2, LG3, LG4), such as 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).

[0081] 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) and a fourth lens (104, 204). The third lens group (LG3) may include a fifth lens (105, 205). The fourth lens group (LG4) may include a sixth lens (106, 206) and a seventh lens (107, 207).

[0082] The first to seventh lenses (101-107, 201-207) and the image sensor (300) can be arranged sequentially along the optical axis (OA) of the optical system (1000, 1100).

[0083] Each of the multiple lenses may include an effective region and an ineffective region. The effective region can be the area through which light incident on each of the first to seventh lenses (101-107, 201-207) passes. In other words, the effective region is the area where incident light is refracted to achieve optical properties. An ineffective region may be located around the effective region. An ineffective region can be an area where light does not enter. In other words, an ineffective region can be an area unrelated to optical properties. Furthermore, the ineffective region can be an area fixed to a lens barrel (not shown) that houses the lens.

[0084] Reference Figure 21 In the optical systems (1000, 1100) according to the first and second embodiments, at least one of the first to seventh lenses (101-107, 201-207) may be provided with a D-shaped cutting technique. When the D-shaped cutting technique is applied, a portion of the effective diameter of the lens or a rib can be cut to reduce the overall height of the optical system. Here, the height of the entire optical system may refer to the length along the direction perpendicular to the optical axis, which is not TTL. The D-shaped cut lens may have a non-circular shape, wherein the length (A) along the second direction (Y-axis direction) and the length (B) along the first direction (X-axis direction) are different.

[0085] The image sensor (300) is capable of detecting light. The image sensor (300) can detect light that has passed through multiple lenses in sequence, such as the first lens to the seventh lens (101-107, 201-207). The image sensor (300) may include CCD (charge-coupled device) or CMOS (complementary metal-oxide-semiconductor), etc.

[0086] The optical system (1000, 1100) may also include a filter (400). The filter (400) may be disposed between multiple lenses and the image sensor (300). The filter (400) may be disposed between the fourth lens group (LG4) of multiple lens groups (LG1, LG2, LG3, LG4) that is closest to the image sensor (300) and the image sensor (300). For example, the filter (400) may be disposed between a seventh lens (107, 207) and the image sensor (300), which is the last lens of the fourth lens group (LG4) that is closest to the image sensor (300).

[0087] The filter (400) may include at least one optical filter, such as an infrared filter or a cover glass. The filter (400) may transmit light within a defined wavelength band and filter out light in other wavelength bands. When the filter (400) includes an infrared filter, it may block radiant heat emitted from external light from being transferred to the image sensor (300). In addition, the filter (400) may transmit visible light and reflect infrared light.

[0088] The optical system (1000, 1100) may include an aperture (not shown). This aperture can control the amount of light entering the optical system (1000, 1100).

[0089] The aperture can be positioned in front of the first lens (101, 201) or between two lenses selected from the first to the seventh lenses (101-107, 201-207). For example, the aperture can be positioned between the fifth lens (105, 205) and the sixth lens (106, 206). Furthermore, at least one of the first to the seventh lenses (101-107, 201-207) can be used as the aperture. For example, the object side or sensor side of one of the lenses selected from the first to the seventh lenses (101-107, 201-207) can perform the function of an aperture for adjusting the amount of light.

[0090] In the optical systems (1000, 1100) according to the first and second embodiments, a first optical path control member (111) may be disposed on the object side of the first lens (101, 201), or a second optical path control member (112) may be disposed between the seventh lens (107, 207) and the filter (400), or between the seventh lens (107, 207) and the image sensor (300), thereby allowing the optical system to be modularized. In other words, when the optical system (1000, 1100) is arranged in a camera module, the optical system can be modularized to reduce the overall size of the optical system.

[0091] The first optical path control component (111) can be a prism lens. The first optical path control component (111) can 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 component (111) can change the path of light incident from the outside. The first optical path control component (111) can be a mirror. The first optical path control component (111) can rotate the optical path by 90°. The first optical path control component (111) can include an incident surface (P1) for light incidence, a reflecting surface (RS1) for reflecting incident light, and an output surface (P2) for outputting reflected light. The reflecting surface (RS1) has a 45° tilt angle to reflect the principal ray of the incident light at 90° and is used to reflect the incident light towards the third lens (103). The first optical path control component (111) can reflect light incident along the second direction (Y-axis direction) to change the optical path to the first direction (X-axis direction).

[0092] The second optical path control component (112) can be a mirror. The first optical path control component (111) can 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 component (112) can change the path of light incident on the reflective surface. The second optical path control component (112) can be a prism lens. The second optical path control component (112) can rotate the optical path by 90°. The second optical path control component (112) can include a reflective surface for reflecting light. The reflective surface has a 45° tilt angle and reflects the principal ray of the incident light at 90°, thereby reflecting the incident light toward the filter (400) or the image sensor (300). The second optical path control component (112) can reflect light incident along the first direction (X-axis direction) to change the optical path to the second direction (Y-axis direction).

[0093] When the optical systems (1000, 1100) do not include the first optical path control member (111) and the second optical path control member (112), multiple lenses within the optical device including the optical systems (1000, 1100) can be configured to extend along a direction perpendicular to the surface of the optical device. As a result, the multiple lenses may have a high height along the direction perpendicular to the surface of the optical device, making it difficult to form an optical device with an ultra-thin thickness. Prismatic lenses can change the direction of light incident on the optical device along a direction perpendicular to the surface of the optical device to a direction parallel to the surface of the optical device. Therefore, the multiple lenses included in the optical system (1000) can be configured such that they extend along a direction parallel to the surface of the optical device, and the optical device can be formed with a thin thickness.

[0094] More specifically, a prism lens has a refractive index and is used to refract and reflect light, while a mirror has no refractive index and is used to reflect light. When a prism lens or mirror is positioned in front of the first lens, when a mirror is positioned between lenses, or when a mirror is positioned between the lens closest to the sensor and the image sensor, the overall performance of the optical system remains unchanged compared to the case where no prism lens or mirror is present. Conversely, when a prism lens is positioned between lenses, or when a prism lens is positioned between the lens closest to the sensor and the image sensor, the overall performance of the optical system changes compared to the case where no prism lens or mirror is present.

[0095] Therefore, under the condition that the overall performance of the optical system remains unchanged, the additional placement of prisms, lenses, or mirrors can be an optional choice for the modularity of the optical system, regardless of the additional placement of prisms, lenses, or mirrors. In this case, interference with other mechanical components or lenses can be considered, and the spacing and dimensions between the placements can be determined by taking into account the size of the light entering the optical path control components.

[0096] Furthermore, where the overall performance of an optical system is altered by the additional placement of prisms or mirrors, such additional placement may be necessary to ensure the system's performance. In this case, the optical performance varies depending on the size of the prisms or mirrors and the spacing between adjacent lenses; therefore, the initial design conditions should not be arbitrarily changed.

[0097] An optical system according to a first embodiment of the present disclosure will now be described.

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

[0099] Reference Figure 1 The optical system (1000) may include a lens unit, which may include a first lens to a seventh lens (101 to 107). The first lens to the seventh lens (101 to 107) may be arranged sequentially along the optical axis (OA) of the optical system (1000). Light corresponding to the information of the object may pass through the first lens to the seventh lens (101 to 107) and the filter (400) and enter the image sensor (300).

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

[0101] Based on the optical axis, the object-side first surface (S1) of the first lens (101) is convex, and the sensor-side second surface (S2) can also be convex. The first lens (101) can have a shape where both surfaces are convex. The first lens (101) can be made of plastic material and can have an aspherical shape. The aspherical coefficients of the first surface (S1) and the second surface (S2) of the first lens (101) can be set to... Figure 7 L1S1 and L1S2 in the first lens (101). At least one or both of the first surface (S1) and the second surface (S2) of the first lens (101) can be configured to have no critical point from the end of the optical axis to the effective region.

[0102] The second lens (102) can be configured as the second from the object side. The second lens (102) can be configured as the sixth from the sensor side. The second lens (102) can be positioned between the third lens (103) and the fifth lens (105). The second lens (102) can have negative (-) refractive power. The second lens (102) can comprise plastic or glass material. For example, the second lens (102) can be provided by plastic material.

[0103] Based on the optical axis, the object-side third surface (S3) of the second lens (102) can be concave, and the sensor-side fourth surface (S4) can be convex. The second lens (102) can have a meniscus shape that is concave on the object side relative to the optical axis (OA). The second lens (102) can also have a meniscus shape that is convex on the sensor side relative to the optical axis (OA). The second lens (102) can be made of plastic material and can have an aspherical shape. The aspheric coefficients of the third surface (S3) and the fourth surface (S4) can be set to... Figure 7 L2S1 and L2S2 in the second lens (102). At least one or two of the third surface (S3) and the fourth surface (S4) of the second lens (102) can be set to have no critical point from the end of the optical axis to the effective region.

[0104] The third lens (103) can be configured as the third from the object side. The third lens (103) can be configured as the fifth from the sensor side. The third lens (103) can be positioned between the third lens (103) and the fifth lens (105). The third lens (103) can have negative (-) refractive power. The third lens (103) can comprise plastic or glass material. For example, the third lens (103) can be provided by plastic material.

[0105] Based on the optical axis, the object-side fifth surface (S5) of the third lens (103) can be convex, and the sensor-side sixth surface (S6) can be concave. The third lens (103) can have a meniscus shape that is convex on the object side relative to the optical axis (OA). The third lens (103) can also have a meniscus shape that is concave on the sensor side relative to the optical axis (OA). The third lens (103) can be made of plastic material and can have an aspherical shape. The aspheric coefficients of the fifth surface (S5) and the sixth surface (S6) can be set to... Figure 7 L3S1 and L3S2 in the third lens (103). At least one or both of the fifth surface (S5) and the sixth surface (S6) of the third lens (103) can be set to have no critical point from the end of the optical axis to the effective region.

[0106] The fourth lens (104) can be configured as a fourth lens from the object side. The fourth lens (104) can also be configured as a fourth lens from the sensor side. The fourth lens (104) can be positioned between the third lens (103) and the fifth lens (105). The fourth lens (104) can have positive (+) refractive power. The fourth lens (104) can comprise plastic or glass material. For example, the fourth lens (104) can be made of plastic material.

[0107] Based on the optical axis, the object-side seventh surface (S7) of the fourth lens (104) can be convex, and the sensor-side eighth surface (S8) can also be convex. The fourth lens (104) can have a shape where both surfaces are convex. The fourth lens (104) can be made of plastic material and can have aspherical surfaces. The aspherical coefficients of the seventh surface (S7) and the eighth surface (S8) can be set to... Figure 7 L4S1 and L4S2 in the fourth lens (104). At least one or both of the seventh surface (S7) and the eighth surface (S8) of the fourth lens (104) can be set to have no critical point from the end of the optical axis to the effective region.

[0108] The fifth lens (105) can be configured as the fifth from the object side. The fifth lens (105) can be configured as the third from the sensor side. The fifth lens (105) can be positioned between the fourth lens (104) and the sixth lens (106). The fifth lens (105) can have negative (-) refractive power. The fifth lens (105) can comprise plastic or glass material. For example, the fifth lens (105) can be provided by plastic material.

[0109] Relative to the optical axis (OA), the object-side ninth surface (S9) of the fifth lens (105) can be concave, and the sensor-side tenth surface (S10) can also be concave. The fifth lens (105) can have concave shapes on both sides. The fifth lens (105) is made of plastic material and can have an aspherical shape. The aspherical coefficients of the ninth surface (S9) and the tenth surface (S10) can be set to... Figure 7 L5S1 and L5S2 in the fifth lens (105). At least one or both of the ninth surface (S9) and the tenth surface (S10) of the fifth lens (105) can be configured to have no critical point from the end of the optical axis to the effective region.

[0110] An aperture (stop) can be positioned between the fifth lens (105) and the sixth lens (106). The aperture can be positioned on the sensor-side tenth surface (S10) of the fifth lens (105) or on the object-side eleventh surface (S11) of the sixth lens (106). The aperture reduces the TTL within the field of view, enabling miniaturization of the optical system. This prevents a decrease in the weight-based yield of the optical system and improves production efficiency.

[0111] The sixth lens (106) can be configured as the sixth lens from the object side. The sixth lens (106) can be configured as the second lens from the sensor side. The sixth lens (106) can be positioned between the fifth lens (105) and the seventh lens (107). The sixth lens (106) can have positive (+) refractive power. The sixth lens (106) can comprise plastic or glass material. For example, the sixth lens (106) can be provided by plastic material.

[0112] Relative to the optical axis (OA), the sixth lens (106) may have a convex first surface (S11) on the object side and a convex second surface (S12) on the sensor side. The sixth lens (106) may have a shape where both surfaces are convex. The sixth lens (106) may be made of plastic material and may have aspherical surfaces. The aspherical coefficients of the first eleventh surface (S11) and the second twelfth surface (S12) of the first lens (106) may be set to... Figure 7 L6S1 and L6S2 in the sixth lens. At least one or both of the first eleventh surface (S11) and the second twelfth surface (S12) of the sixth lens can be set to have no critical point from the end of the optical axis to the effective region.

[0113] The seventh lens (107) can be positioned closest to the sensor side. The seventh lens (107) can be positioned furthest from the object side. The seventh lens (107) can be positioned between the sixth lens (106) and the filter (400). The seventh lens (107) can be positioned between the sixth lens (106) and the image sensor (300). The seventh lens (107) can have negative (-) refractive power. The seventh lens (107) can comprise plastic or glass material. For example, the seventh lens (107) can be made of plastic material.

[0114] Based on the optical axis (OA), the seventh lens (107) can have a concave first surface (S13) on the object side and a concave second surface (S14) on the sensor side. The seventh lens (107) can have concave shapes on both sides. The seventh lens (107) can be made of plastic and can have an aspherical shape. The aspherical coefficients of the thirteenth surface (S13) and the fourteenth surface (S14) can be set to... Figure 7 L7S1 and L7S2 in the seventh lens (107). At least one or two of the thirteenth surface (S13) and the fourteenth surface (S14) of the seventh lens (107) can be set to have no critical point from the end of the optical axis to the effective region.

[0115] Table 1

[0116] 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), effective aperture (clear aperture) and focal length (focal length) of the lens according to the first embodiment of this disclosure. Here, the units for radius of curvature and thickness or distance may be mm.

[0117] Table 2

[0118] Table 2 shows the spacing (D1, D2, D3) between the variable lenses when the optical system according to the first embodiment of this disclosure is operated in any of the first to third modes. Here, the first mode refers to the wide-angle mode, the second mode refers to the intermediate mode, and the third mode refers to the telephoto mode. The wide-angle mode can be referred to as wide-angle, and the telephoto mode can be referred to as telephoto.

[0119] In the optical system according to the first embodiment of this disclosure, the distance between adjacent lens groups can be changed during the process of changing the magnification from a first mode to a third mode. The fourth lens group (LG4) can be fixed, and only the first to third lens groups (LG1, LG2, LG3) can be movable. The fourth lens group (LG4) can be a fixed group, and the first to third lens groups (LG1, LG2, LG3) can be movable groups.

[0120] When switching from the first mode to the second mode, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) can be increased, the distance (D2) between the second lens group (LG2) and the third lens group (LG3) can be increased, and the distance (D3) between the third lens group (LG3) and the fourth lens group (LG4) can be decreased.

[0121] When switching from the second mode to the third mode, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) can be increased, the distance (D2) between the second lens group (LG2) and the third lens group (LG3) can be increased, and the distance (D3) between the third lens group (LG3) and the fourth lens group (LG4) can be decreased.

[0122] When switching from the first mode to the third mode, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) can be increased, the distance (D2) between the second lens group (LG2) and the third lens group (LG3) can be increased, and the distance (D3) between the third lens group (LG3) and the fourth lens group (LG4) can be decreased.

[0123] The travel length of the first lens group (LG1) can be from 0.5 mm to 1 mm, and preferably about 0.870 mm. The travel length of the second lens group (LG2) can be from 2 mm to 4 mm, and preferably about 3.820 mm.

[0124] The travel length of the third lens group (LG3) can be between 3 mm and 5 mm, and preferably about 4.320 mm. The travel length of the third lens group (LG3) can be greater than the travel length of the first lens group (LG1) and can be greater than the travel length of the second lens group (LG2). The first lens group (LG1), the second lens group (LG2), and the third lens group (LG3) can have different movement speeds. The movement speed of the third lens group (LG3) can be greater than the movement speed of the first lens group (LG1) and the second lens group (LG2). In this first embodiment, the magnification ratio between the wide-angle end and the telephoto end can be in the range of 1.5x to 2x, and can be approximately 1.99x.

[0125] The CRA (1-field) deviation between the first and third modes can satisfy conditions of 0.5 degrees or greater and 5 degrees or less. Here, CRA (1-field) can refer to the angle formed between the normal perpendicular to the image sensor and the principal ray (principal ray, upper ray, and lower ray) of the incident rays entering the 1-field region of the image sensor. The point where the image sensor intersects the optical axis is 0-field, and the endpoint of the image sensor can be 1-field. If the CRA (1-field) deviation between mode 1 and mode 3 exceeds 5 degrees, resolution degradation occurs, and the distance between the fourth lens group (LG4) and the image sensor (300) may become too close, making it impossible to arrange the optical path control components. If the CRA (1-field) deviation between the first and third modes is less than 0.5 degrees, the sensitivity to changes in zoom ratio increases, which leads to a decrease in optical performance.

[0126] When capturing an object at infinity, the first to third modes can correspond to wide-angle, intermediate, and telephoto focal lengths, respectively. When shooting an object at close range (macro, e.g., within 1000mm), the first lens group (LG1) in the first to third modes can move toward the object. That is, when shooting an object at infinity in modes 1 to 3 and then switching to shooting an object at close range, the first lens group (LG1) moves toward the object, increasing the distance between the first lens group (LG1) and the second lens group (LG2). In this case, the travel length of the first lens group (LG1) can be between 0.2 mm and 0.5 mm, and preferably between 0.3 mm and 0.45 mm.

[0127] Table 3

[0128] Table 3 shows the values ​​of the items in the above mathematical formulas in the optical system (1000) of the first embodiment. Specifically, for the wide-angle, intermediate, and telephoto segments of the optical system (1000), the effective focal length (F) (mm), back focal length (BFL) (mm), and EPD (mm), the optical axis distance from the aperture (stop) to the fourteenth surface (S14) (SD (mm)), Fno, FOV (degrees), and the focal lengths (F1-F7) (mm) and edge thicknesses (ET1-ET7) of the first to seventh lenses (101-107), the focal lengths (f_LG1, f_LG2, f_LG3, f_LG4) of the first to fourth lens groups, and the stroke length (LG1_stroke) of the first lens group (LG1). The stroke length of the second lens group (LG2), the stroke length of the third lens group (LG3), the total optical axis distance (TTL) (mm) of the optical system (1000), ImgH (mm), the maximum effective aperture (CA_Max), the minimum effective aperture (CA_Min), the average effective aperture (CA_Aver), the maximum center thickness (L_CT_max), the minimum center thickness (L_CT_min), and the average center thickness (L_CT_aver) of the first to seventh lenses (101-107), as well as the length of each lens group along the optical axis (TD_LG1, TD_LG2, TD_LG3, TD_LG4), etc.

[0129] In the following text, the center thickness of the first to seventh lenses (101 to 107) is denoted as CT1 to CT7, the edge thickness at the end of the effective area of ​​each lens is denoted as ET1 to ET7, and the center gap between adjacent lenses is denoted as CG1 to CG6. BFL (back focal length) is the optical axis distance from the image sensor (300) to the center of the last lens. 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).

[0130] When comparing the absolute values ​​of the radii of curvature of each lens, the radius of curvature of the fourteenth surface (S14) of the seventh lens (107) on the optical axis (OA) is the largest among the lenses, while the radii of curvature of the sixth surface (S6) of the third lens (103) and the eleventh surface (S11) of the sixth lens (106) are the smallest. The absolute value of the radius of curvature (S1) of the first surface of the first lens (101) can be greater than the absolute value of the radius of curvature (S2) of the second surface. The absolute value of the radius of curvature of the third surface (S3) of the second lens (102) can be less than the absolute value of the radius of curvature of the fourth surface (S4). The absolute value of the radius of curvature of the fifth surface (S5) of the third lens (103) can be greater than the absolute value of the radius of curvature of the sixth surface (S6). The absolute value of the radius of curvature of the seventh surface (S7) of the fourth lens (104) can be less than the absolute value of the radius of curvature of the eighth surface (S8). The absolute value of the radius of curvature of the ninth surface (S9) of the fifth lens (105) can be greater than the absolute value of the radius of curvature of the tenth surface (S10). The absolute value of the radius of curvature of the eleventh surface (S11) of the sixth lens (106) can be less than the absolute value of the radius of curvature of the twelfth surface (S12). The absolute value of the radius of curvature of the thirteenth surface (S13) of the seventh lens 107 can be less than the absolute value of the radius of curvature of the fourteenth surface (S14).

[0131] Condition 1: 1 < |L1R1 / L1R2| < 1.5

[0132] Condition 2: 0.5 < |L2R1 / L2R2| < 1

[0133] Condition 3: 5 < |L3R1 / L3R2| < 10

[0134] Condition 4: 0.1 < |L4R1 / L4R2| < 0.5

[0135] Condition 5: 1 < |L5R1 / L5R2| < 1.5

[0136] Condition 6: 0.5 < |L6R1 / L6R2| < 1

[0137] Condition 7: 0.01 < |L7R1 / L7R2| < 0.1

[0138] When describing the central thickness of a lens based on its optical axis, the central thicknesses (CT6, CT7) of the sixth lens (106) and the seventh lens (107) can be the largest among the lenses, and the central thickness (CT5) of the fifth lens (105) can be the smallest among the lenses. The difference between the maximum and minimum central thickness of a lens can be in the range of 1.8 mm or greater and 2.2 mm or less.

[0139] The center thickness of each lens can satisfy any of the following conditions.

[0140] Condition 1: CT6, CT7 > CT1 > CT2, CT3, CT4, CT5

[0141] Condition 2: CT1, CT4, CT6, CT7 > CT2 > CT3, CT5

[0142] Condition 3: CT1, CT2, CT4, CT6, CT7 > CT3 > CT5

[0143] Condition 4: CT1, CT6, CT7 > CT4 > CT2, CT3, CT5

[0144] Condition 5: CT1, CT2, CT3, CT4, CT6, CT7 > CT5

[0145] Condition 6: CT6 = CT7 > CT1, CT2, CT3, CT4, CT5

[0146] When the zoom is moved, the distances (gap, CG1) between the first lens (101) and the second lens (102), the distances (CG3) between the third lens (103) and the fourth lens (104), and the distances (CG6) between the sixth lens (106) and the seventh lens (107) can remain constant, while the distances (CG2) between the second lens (102) and the third lens (103), the distances (CG4) between the fourth lens (104) and the fifth lens (105), and the distances (CG5) between the fifth lens (105) and the sixth lens (106) can change. Among the center-to-center distances between the lenses that remain constant, the distance (CG3) between the third lens (103) and the fourth lens (104) can be the maximum, and the distance (CG6) between the sixth lens (106) and the seventh lens (107) can be the minimum. The difference between the maximum and minimum center distances among the individual lens distances can be 0.3 mm or greater, for example, in the range of 0.4 mm to 0.6 mm.

[0147] The center distance (gap) between each lens can satisfy the following conditions.

[0148] Condition 1: CG3 > CG1 > CG6

[0149] Condition 2: CG3 > CG1, CG6

[0150] Condition 3: CG1, CG3 > CG6

[0151] Regarding the effective aperture, the lens with the largest effective aperture can be the first lens (101). Here, the effective aperture is the average of the effective aperture on the object-side surface and the effective aperture on the sensor-side surface of each lens. The lens surface with the largest effective aperture can be the first surface (S1) of the first lens (101). The lens with the smallest effective aperture can be the seventh lens (107). The lens surface with the smallest effective aperture can be the fourteenth surface (S14) of the seventh lens (107). The effective apertures of the first to seventh lenses (101-107) can be greater than the diagonal length of the image sensor (300).

[0152] The effective aperture of each lens can satisfy any of the following conditions.

[0153] Condition 1: CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0154] Condition 2: CA_L1 > CA_L2 > CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0155] Condition 3: CA_L1, CA_L2, CA_L6 > CA_L3 > CA_L4, CA_L5, CA_L7

[0156] Condition 4: CA_L1, CA_L2, CA_L3, CA_L6 > CA_L4 > CA_L5, CA_L7

[0157] Condition 5: CA_L1, CA_L2, CA_L3, CA_L4, CA_L6 > CA_L5 > CA_L7

[0158] Condition 6: CA_L1, CA_L2 > CA_L6 > CA_L3, CA_L4, CA_L5, CA_L7

[0159] Condition 7: CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L6 > CA_L7

[0160] Regarding refractive index, the refractive indices of the second lens (102) and the fourth lens (104) can be the highest among the lenses and can exceed 1.6, for example, 1.65. Any one of the first lens (101), the fifth lens (105), and the sixth lens (106) can 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) can be the lowest among the lenses and less than 1.6, such as less than 1.55. The difference between the maximum and minimum refractive indices can be 0.1 or greater.

[0161] The refractive index of each lens can satisfy any of the following conditions.

[0162] Condition 1: n2, n3, n4, n7 > n1 = n5 = n6

[0163] Condition 2: n2 = n4 > n1, n3, n5, n6, n7

[0164] Condition 3: n2, n4, n7 > n3 > n1, n5, n6

[0165] Condition 4: n2, n4 > n7 > n1, n3, n5, n6

[0166] When comparing Abbe numbers, the Abbe numbers of the first lens (101), the fifth lens (105), and the sixth lens (106) can be the largest among the lenses, and can be 50 or greater. The Abbe numbers of the second lens (102) and the fourth lens (104) can be the smallest among the lenses, and can be 20 or less. The difference between the maximum refractive index and the minimum Abbe number can be 30 or greater.

[0167] The Abbe number of each lens can satisfy any of the following conditions.

[0168] Condition 1: v1 = v5 = v6 > v2, v3, v4, v7

[0169] Condition 2: v1, v3, v5, v6, v7 > v2 = v4

[0170] Condition 3: v1, v5, v6 > v3 > v2, v4, v7

[0171] Condition 4: v1, v3, v5, v6 > v7 > v2, v4

[0172] The focal lengths (F1, F4, F6) of the first, fourth, and sixth lenses (101, 104, 106) can have a positive (+) sign. The first, fourth, and sixth lenses (101, 104, 106) can have a positive (+) refractive power. The focal lengths (F2, F3, F5, F7) of the second, third, fifth, and seventh lenses (102, 103, 105, 107) can have a negative (-) sign. The second, third, fifth, and seventh lenses (102, 103, 105, 107) can have a negative (-) refractive power. When comparing focal lengths in absolute values, the second lens (102) can have the largest focal length among the lenses, and it can be 20 or greater and 40 or less. The sixth lens (106) can have the smallest focal length among the lenses, and the absolute value of the focal length of the sixth lens (106) can be 5 or greater and 8 or less.

[0173] The absolute value of the focal length of each lens can satisfy any of the following conditions.

[0174] Condition 1: |f2|、|f7| > |f1| > |f3|、|f4|、|f5|、|f6|

[0175] Condition 2: |f2| > |f1|, |f3|, |f4|, |f5|, |f6|, |f7|

[0176] Condition 3: |f1|、|f2||f4|、|f7| > |f3| > |f5|、|f6|

[0177] Condition 4: |f1|、|f2|、|f7| > |f4| > |f3|、|f5|、|f6|

[0178] Condition 5: |f1|, |f2|, |f3|, |f4|, |f7| > |f5| > |f6|

[0179] Condition 6: |f1|, |f2|, |f3|, |f4|, |f5|, |f7| > |f6|

[0180] Condition 7: |f2| > |f7| > |f1|, |f3|, |f4|, |f5|, |f6|

[0181] The compound focal length (f_LG1) of the first lens group (LG1) can have a positive (+) sign. The first lens group (LG1) can have a positive (+) compound refractive power. The compound focal length (f_LG2) of the second lens group (LG2) can have a positive (+) sign. The second lens group (LG2) can have a positive (+) compound refractive power. The compound focal length (f_LG3) of the third lens group (LG3) can have a negative (-) sign. The third lens group (LG3) can have a negative (-) compound refractive power. The fourth lens group (LG4) can have a positive (+) focal length (f_LG4). The fourth lens group (LG4) can have a positive (+) refractive power. This allows light incident from the object side to move away from the optical axis and then converge toward the optical axis to form a stable optical path.

[0182] When comparing the absolute values ​​of the compound focal lengths of the first to fourth lens groups (LG1, LG2, LG3, LG4), the compound focal length of the second lens group (LG2) can be the largest, and the compound focal length of the third lens group (LG3) can be the smallest. The relative order of the compound focal lengths of the first to fourth lens groups (LG1, LG2, LG3, LG4) can satisfy the condition |f_LG2| > |f_LG1| > |f_LG4| > |f_LG3|.

[0183] The thickness (CT1) of the first lens (101) can have a difference of at least twice between the maximum and minimum thickness, for example, in the range of 2.5 to 3 times, wherein the center thickness (CT1) is the largest and the edge thickness (ET1) is the smallest. The thickness (T2) of the second lens (102) can be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 1 to 1.5 times the minimum thickness. The thickness (T3) of the third lens (103) can be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T4) of the fourth lens (104) can be the largest at the center and the smallest at the edge, wherein the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T5) of the fifth lens (105) can be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T6) of the sixth lens (106) can be the greatest at the center and the least at the edge, with the maximum thickness ranging from 2.5 to 3 times the minimum thickness. The thickness (T7) of the seventh lens (107) can be the least at the center and the greatest at the edge, with the maximum thickness ranging from 1 to 1.5 times the minimum thickness.

[0184] The thickness of each lens can satisfy any of the following conditions.

[0185] Condition 1: 2.5 < CT1 / ET1 < 3, 0.1 < ET1 / CT1 < 0.5

[0186] Condition 2: 0.5 < CT2 / ET2 < 1, 1 < ET2 / CT2 < 1.5

[0187] Condition 3: 0.1 < CT3 / ET3 < 0.5, 2.5 < ET3 / CT3 < 3

[0188] Condition 4: 2 < CT4 / ET4 < 2.5, 0.1 < ET4 / CT4 < 0.5

[0189] Condition 5: 0.1 < CT5 / ET5 < 0.5, 2.5 < ET5 / CT5 < 3

[0190] Condition 6: 2.5 < CT6 / ET6 < 3, 0.1 < ET6 / CT6 < 0.5

[0191] Condition 7: 0.5 < CT7 / ET7 < 1, 1 < ET7 / CT7 < 1.5

[0192] Condition 8: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0193] Among the gaps (distances, G1-G6) between the lenses, the gap (LG1) between the first and second lenses (101, 102) can be largest at the center and smallest at the edge. The gap (LG2) between the second and third lenses (102, 103) can be smallest at the center and largest at the edge. The gap (LG3) between the third and fourth lenses (103, 104) can have a maximum value at the center and a minimum value at the edge. The gap (G4) between the fourth and fifth lenses (104, 105) can have a maximum value at the edge and a minimum value at the center. The fifth gap (G5) between the fifth and sixth lenses (105, 106) can have a minimum value at the center and a maximum value at the edge. The sixth gap (G6) between the sixth and seventh lenses (106, 107) can have a minimum value at the center and a maximum value at the edge.

[0194] Figure 8 This is a graph showing data regarding the aberration characteristics of the optical system according to the first embodiment operating in the first mode. Figure 9 It is a graph showing data on the aberration characteristics of the optical system according to the first embodiment operating in the second mode, and Figure 10 It is a graph showing the aberration characteristics of the optical system according to the first embodiment operating in the third mode. Figure 8 , 9 Figures 10 and 10, from left to right, show graphs measuring spherical aberration (longitudinal spherical aberration), astigmatic field curves, and distortion. Figure 8 , 9 In Figure 10, the X-axis represents focal length (mm) and distortion percentage (%), and the Y-axis represents image height. Furthermore, the spherical aberration curve corresponds to light in the wavelength bands of approximately 435 nm, 486 nm, 546 nm, 587 nm, and 656 nm, while the astigmatism and distortion curves correspond to light in the wavelength band of approximately 546 nm. Figure 8 , 9 In the aberration diagram of 10, the closer the curve is to the Y-axis, the better the aberration correction performance is interpreted. In the optical system (1000) according to the first embodiment, it can be seen that the measured value is adjacent to the Y-axis in almost all regions. In other words, the optical system (1000) according to the first embodiment has improved resolution and achieves good optical performance not only in the central region of the field of view (FOV) but also in the peripheral region.

[0195] An optical system according to a second embodiment of the present disclosure will now be described.

[0196] Figure 11 This is a configuration diagram of an optical system operating in a first mode according to a second exemplary embodiment. Figure 12 This is a modular configuration diagram of an optical system operating in a first mode according to the second embodiment. Figure 13 This is a configuration diagram of an optical system operating in a second mode according to the second embodiment. Figure 14 This is a modular configuration diagram of an optical system operating in a second mode according to the second embodiment. Figure 15 This is a configuration diagram of an optical system operating in a third mode according to the second embodiment. Figure 16 This is a modular configuration diagram of an optical system operating in a third mode according to the second embodiment. Figure 17 This is a table showing the aspherical coefficients of the lenses in the optical system according to the second embodiment. Figure 18 This is a graph showing data regarding the aberration characteristics of the optical system operating in the first mode according to the second embodiment. Figure 19 This is a graph showing data regarding the aberration characteristics of the optical system operating in the second mode according to the second embodiment. Figure 20 It is a graph showing the aberration characteristics of the optical system operating in the third mode according to the second embodiment.

[0197] Reference Figure 11 The optical system (1100) may include a lens unit, which may include a first lens to a seventh lens (201 to 207). The first lens to the seventh lens (201 to 207) may be arranged sequentially along the optical axis (OA) of the optical system (1100). Light corresponding to the information of the object may pass through the first lens to the seventh lens (201–207) and the filter (400) and enter the image sensor (300).

[0198] The first lens (201) can be positioned closest to the object side. The first lens (201) can be positioned furthest from the sensor side. The first lens (201) can have positive (+) refractive power. The first lens (201) can comprise plastic or glass material. For example, the first lens (201) can be provided from plastic material.

[0199] Based on the optical axis, the object-side first surface (S1) of the first lens (201) can be convex, and the sensor-side second surface (S2) can also be convex. The first lens (201) can have a shape where both surfaces are convex. The first lens (201) can be made of plastic material and can have an aspherical shape. The aspherical coefficients of the first surface (S1) and the second surface (S2) of the first lens (201) can be set to... Figure 17L1S1 and L1S2 in the first lens (201). At least one or both of the first surface (S1) and the second surface (S2) of the first lens (201) can be configured to have no critical point from the end of the optical axis to the effective region.

[0200] The second lens (202) can be configured as the second from the object side. The second lens (202) can be configured as the sixth from the sensor side. The second lens (202) can be positioned between the third lens (203) and the fifth lens (205). The second lens (202) can have negative (-) refractive power. The second lens (202) can comprise plastic or glass material. For example, the second lens (202) can be provided by plastic material.

[0201] Based on the optical axis, the object-side third surface (S3) of the second lens (202) can be concave, and the sensor-side fourth surface (S4) can be convex. The second lens (202) can have a meniscus shape that is concave on the object side relative to the optical axis (OA). The second lens (202) can also have a meniscus shape that is convex on the sensor side relative to the optical axis (OA). The second lens (202) can be made of plastic material and can have aspherical surfaces. The aspheric coefficients of the third surface (S3) and the fourth surface (S4) can be set to... Figure 17 L2S1 and L2S2 in the second lens (202). At least one or both of the third surface (S3) and the fourth surface (S4) of the second lens (202) can be configured to have no critical point from the end of the optical axis to the effective region.

[0202] The third lens (203) can be configured as a third lens from the object side. The third lens (203) can also be configured as a fifth lens from the sensor side. The third lens (203) can be positioned between the third lens (203) and the fifth lens (205). The third lens (203) can have negative (-) refractive power. The third lens (203) can comprise plastic or glass material. For example, the third lens (203) can be made of plastic material.

[0203] Based on the optical axis, the object-side fifth surface (S5) of the third lens (203) can be concave, and the sensor-side sixth surface (S6) can also be concave. The third lens (203) can have concave shapes on both sides. The third lens (203) can be made of plastic and can have an aspherical shape. The aspherical coefficients of the fifth surface (S5) and the sixth surface (S6) can be set to... Figure 17 L3S1 and L3S2 in the third lens (203). At least one or two of the fifth surface (S5) and the sixth surface (S6) of the third lens (203) can be set to have no critical point from the end of the optical axis to the effective region.

[0204] The fourth lens (204) can be configured as a fourth lens originating from the object side. The fourth lens (204) can be configured as a fourth lens originating from the sensor side. The fourth lens (204) can be positioned between the third lens (203) and the fifth lens (205). The fourth lens (204) can have positive (+) refractive power. The fourth lens (204) can comprise plastic or glass material. For example, the fourth lens (204) can be made of plastic material.

[0205] Based on the optical axis, the object-side seventh surface (S7) of the fourth lens (204) can be convex, and the sensor-side eighth surface (S8) can also be convex. The fourth lens (204) can have a shape where both surfaces are convex. The fourth lens (204) can be made of plastic material and can have an aspherical shape. The aspherical coefficients of the seventh surface (S7) and the eighth surface (S8) can be set to... Figure 17 L4S1 and L4S2 in the fourth lens (204). At least one or both of the seventh surface (S7) and the eighth surface (S8) of the fourth lens (204) can be set to have no critical point from the end of the optical axis to the effective region.

[0206] The fifth lens (205) can be configured as the fifth lens from the object side. The fifth lens (205) can also be configured as the third lens from the sensor side. The fifth lens (205) can be positioned between the fourth lens (204) and the sixth lens (206). The fifth lens (205) can have negative (-) refractive power. The fifth lens (205) can comprise plastic or glass material. For example, the fifth lens (205) can be made of plastic material.

[0207] Relative to the optical axis (OA), the object-side ninth surface (S9) of the fifth lens (205) can be concave, and the sensor-side tenth surface (S10) can also be concave. The fifth lens (205) can have concave shapes on both sides. The fifth lens (205) can be made of plastic material and can have an aspherical shape. The aspherical coefficients of the ninth surface (S9) and the tenth surface (S10) can be set to... Figure 17 In the fifth lens (205), at least one or two of L5S1 and L5S2, the ninth surface (S9) and the tenth surface (S10) can be configured to have no critical point at the end from the optical axis to the effective region.

[0208] An aperture (stop) can be positioned between the fifth lens (205) and the sixth lens (206). The aperture can be positioned on the sensor-side tenth surface (S10) of the fifth lens (205) or on the object-side eleventh surface (S11) of the sixth lens (206). The aperture reduces the TTL within the field of view, enabling miniaturization of the optical system. This prevents a decrease in the weight-based yield of the optical system and improves production efficiency.

[0209] The sixth lens (206) can be configured as the sixth lens from the object side. The sixth lens (206) can be configured as the second lens from the sensor side. The sixth lens (206) can be positioned between the fifth lens (205) and the seventh lens (207). The sixth lens (206) can have positive (+) refractive power. The sixth lens (206) can comprise plastic or glass material. For example, the sixth lens (206) can be made of plastic material.

[0210] Relative to the optical axis (OA), the object-side eleventh surface (S11) of the sixth lens (206) can be convex, and the sensor-side twelfth surface (S12) can also be convex. The sixth lens (206) can have a shape where both surfaces are convex. The sixth lens (206) can be made of plastic material and can have an aspherical shape. The aspherical coefficients of the eleventh surface (S11) and the twelfth surface (S12) can be set to... Figure 17 L6S1 and L6S2 in the sixth lens (206). At least one or both of the eleventh surface (S11) and the twelfth surface (S12) of the sixth lens (206) can be set to have no critical point from the end of the optical axis to the effective region.

[0211] The seventh lens (207) can be positioned closest to the sensor side. The seventh lens (207) can be positioned furthest from the object side. The seventh lens (207) can be positioned between the sixth lens (206) and the filter (400). The seventh lens (207) can be positioned between the sixth lens (206) and the image sensor (300). The seventh lens (207) can have negative (-) refractive power. The seventh lens (207) can comprise plastic or glass material. For example, the seventh lens (207) can be made of plastic material.

[0212] Relative to the optical axis (OA), the object-side thirteenth surface (S13) of the seventh lens (207) can be concave, and the sensor-side fourteenth surface (S14) can also be concave. The seventh lens (207) can have concave shapes on both sides. The seventh lens (207) can be made of plastic material and can have an aspherical shape. The aspherical coefficients of the thirteenth surface (S13) and the fourteenth surface (S14) can be set to... Figure 17L7S1 and L7S2. At least one or both of the thirteenth surface (S13) and the fourteenth surface (S14) of the seventh lens (207) can be configured to have no critical point at the end from the optical axis to the effective region.

[0213] Table 4

[0214] 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), effective aperture (light-transmitting aperture), and focal length (focal length) of the lenses according to the second embodiment of this disclosure. Here, the units for radius of curvature and thickness or distance may be mm.

[0215] Table 5

[0216] Table 5 shows the gaps (spacing, D1, D2, D3) between the variable lenses when the optical system according to the second embodiment of this disclosure is operated in any of the first to third modes. Here, the first mode refers to the wide-angle mode, the second mode refers to the intermediate mode, and the third mode refers to the telephoto mode. The wide-angle mode can be referred to as wide-angle, and the telephoto mode can be referred to as telephoto.

[0217] In the optical system according to the second embodiment of this disclosure, the distance between adjacent lens groups can be changed during the process of changing the magnification from the first mode to the third mode. The fourth lens group (LG4) can be fixed, and only the first to third lens groups (LG1, LG2, LG3) can be movable. The fourth lens group (LG4) can be a fixed group, and the first to third lens groups (LG1, LG2, LG3) can be movable groups.

[0218] When switching from the first mode to the second mode, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) can be increased, the distance (D2) between the second lens group (LG2) and the third lens group (LG3) can be increased, and the distance (D3) between the third lens group (LG3) and the fourth lens group (LG4) can be decreased.

[0219] When switching from the second mode to the third mode, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) can be increased, the distance (D2) between the second lens group (LG2) and the third lens group (LG3) can be increased, and the distance (D3) between the third lens group (LG3) and the fourth lens group (LG4) can be decreased.

[0220] When operating from mode 1 to mode 3, the distance (D1) between the first lens group (LG1) and the second lens group (LG2) can be increased, the distance (D2) between the second lens group (LG2) and the third lens group (LG3) can be increased, and the distance (D3) between the third lens group (LG3) and the fourth lens group (LG4) can be decreased.

[0221] The travel length of the first lens group (LG1) can be from 0.5 mm to 1 mm, and preferably about 0.990 mm. The travel length of the second lens group (LG2) can be from 3.5 mm to 4.5 mm, and preferably about 4.010 mm. The travel length of the third lens group (LG3) can be from 4 mm to 4.8 mm, and preferably about 4.330 mm. The travel length of the third lens group (LG3) can be greater than that of the first lens group (LG1) and greater than that of the second lens group (LG2). The first lens group (LG1), the second lens group (LG2), and the third lens group (LG3) can have different relative movement speeds. The movement speed of the third lens group (LG3) can be greater than that of the first lens group (LG1) and the second lens group (LG2). In this second embodiment, the magnification between the wide-angle end and the telephoto end can be in the range of 1.5x to 2x, and can meet a magnification ratio of about 1.99x.

[0222] Modes 1 to 3 correspond to objects located at infinity when shooting (capturing) using wide-angle, intermediate, and telephoto lenses. When shooting objects at close range (macro, e.g., within 1000 mm), the first lens group (LG1) can move toward the object in modes 1 to 3. That is, when shooting an object at infinity in the first to third modes and then shooting an object at close range, the first lens group (LG1) moves toward the object to increase the distance between the first lens group (LG1) and the second lens group (LG2). In this case, the travel length of the first lens group (LG1) can be between 0.2 mm and 0.5 mm, and preferably between 0.2 mm and 0.3 mm.

[0223] The CRA (1-field) deviation between the first and third modes can be 0.5 degrees or greater and 5 degrees or less. Here, CRA (1-field) can represent the angle formed between the principal ray and the normal perpendicular to the image sensor, where the principal ray is one of the incident rays (upper ray, principal ray, and lower ray) entering the 1-field region of the image sensor. The point where the image sensor intersects the optical axis is 0-field, and the endpoints of the image sensor can be 1-field. If the CRA (1-field) deviation between the first and third modes exceeds 5 degrees, resolution degradation occurs, and the distance between the fourth lens group (LG4) and the image sensor (300) may become too close, making it impossible to arrange the optical path control components. If the CRA (1-field) deviation between the first and third modes is less than 0.5 degrees, the sensitivity to changes in zoom ratio may increase, leading to optical performance degradation.

[0224] Table 6

[0225] Table 6 shows the values ​​of the items in the above mathematical formula in the optical system (1100) of the second embodiment. Specifically, for the wide-angle, intermediate, and telephoto segments of the optical system (1100), the effective focal length (F) (mm), back focal length (BFL) (mm), and EPD (mm), the optical axis distance from the aperture (stop) to the fourteenth surface (S14) (SD (mm)), Fno, FOV (degrees), and the focal length (F1-F7) (mm) and edge thickness (ET1-ET7) of the first to seventh lenses (201-207), the focal length (f_LG1, f_LG2, f_LG3, f_LG4) (mm) of the first lens group to the fourth lens group, and the travel length (LG1_strok) of the first lens group (LG1). e) The stroke length of the second lens group (LG2) (LG2_stroke), the stroke length of the third lens group (LG3) (LG3_stroke), the total optical axis distance (TTL) (mm) of the optical system (1100) (ImgH (mm), the maximum effective aperture (CA_Max), the minimum effective aperture (CA_Min), the average effective aperture (CA_Aver), the maximum center thickness (L_CT_max), the minimum center thickness (L_CT_min), and the average center thickness (L_CT_aver) of the first to seventh lenses (201-207), as well as the length of each lens group along the optical axis (TD_LG1, TD_LG2, TD_LG3, TD_LG4), etc.

[0226] In the following text, the center thickness of the first to seventh lenses (201 to 207) is denoted as CT1 to CT7, the edge thickness at the end of the effective area of ​​each lens is denoted as ET1 to ET7, and the center gap between adjacent lenses is denoted as CG1 to CG6. BFL (back focal length) is the optical axis distance from the image sensor (300) to the center of the last lens. 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).

[0227] When comparing the absolute values ​​of the radii of curvature of each lens, the radius of curvature of the fourteenth surface (S14) of the seventh lens (207) at the optical axis OA is the largest among the lenses, and the radius of curvature of the eleventh surface (S11) of the sixth lens (206) is the smallest among the lenses. The absolute value of the radius of curvature of the first surface (S1) of the first lens (201) can be greater than the absolute value of the radius of curvature of the second surface (S2). The absolute value of the radius of curvature of the third surface (S3) of the second lens (202) can be less than the absolute value of the radius of curvature of the fourth surface (S4). The absolute value of the radius of curvature of the fifth surface (S5) of the third lens (203) can be greater than the absolute value of the radius of curvature of the sixth surface (S6). The absolute value of the radius of curvature of the seventh surface (S7) of the fourth lens (204) can be less than the absolute value of the radius of curvature of the eighth surface (S8). The absolute value of the radius of curvature of the ninth surface (S9) of the fifth lens (205) can be greater than the absolute value of the radius of curvature of the tenth surface (S10). The absolute value of the radius of curvature of the eleventh surface (S11) of the sixth lens (206) can be less than the absolute value of the radius of curvature of the twelfth surface (S12). The absolute value of the radius of curvature of the thirteenth surface (S13) of the seventh lens (207) can be less than the absolute value of the radius of curvature of the fourteenth surface (S14).

[0228] Condition 1: 1 < |L1R1 / L1R2| < 1.5

[0229] Condition 2: 0.5 < |L2R1 / L2R2| < 1

[0230] Condition 3: 5 < |L3R1 / L3R2| < 10

[0231] Condition 4: 0.5 < |L4R1 / L4R2| < 1

[0232] Condition 5: 1 < |L5R1 / L5R2| < 1.5

[0233] Condition 6: 0.5 < |L6R1 / L6R2| < 1

[0234] Condition 7: 0.1 < |L7R1 / L7R2| < 0.5

[0235] When describing the center thickness of a lens based on its optical axis, the center thicknesses (CT6, CT7) of the sixth lens (206) and the seventh lens (207) are the largest among the lenses, while the center thickness (CT5) of the fifth lens (205) is the smallest. The difference between the maximum and minimum center thickness of a lens can be in the range of 1.8 mm or greater and 2.2 mm or less.

[0236] The center thickness of each lens can satisfy any of the following conditions.

[0237] Condition 1: CT6, CT7 > CT1 > CT2, CT3, CT4, CT5

[0238] Condition 2: CT1, CT4, CT6, CT7 > CT2 > CT3, CT5

[0239] Condition 3: CT1, CT2, CT4, CT6, CT7 > CT3 > CT5

[0240] Condition 4: CT1, CT6, CT7 > CT4 > CT2, CT3, CT5

[0241] Condition 5: CT6, CT7, CT1, CT2, CT3, CT4 > CT5

[0242] Condition 6: CT6 = CT7 > CT1, CT2, CT3, CT4, CT5

[0243] During zooming, the distances between the first lens (201) and the second lens (202) (CG1), the third lens (203) and the fourth lens (204) (CG3), and the sixth lens (206) and the seventh lens (207) (CG6) remain constant, while the distances between the second lens (202) and the third lens (203) (CG2), the fourth lens (204) and the fifth lens (205) (CG4), and the fifth lens (205) and the sixth lens (206) (CG5) can vary. Among the center-to-center distances between the lenses that remain constant, the distance between the third lens (203) and the fourth lens (204) (CG3) can be the maximum, and the distance between the sixth lens (206) and the seventh lens (207) (CG6) can be the minimum. The difference between the maximum and minimum center distances for each individual lens is 0.3 mm or greater, for example, in the range of 0.2 mm to 0.4 mm.

[0244] The center distance between each lens can satisfy the following conditions.

[0245] Condition 1: CG3 > CG1 > CG6

[0246] Condition 2: CG3 > CG1, CG6

[0247] Condition 3: CG1, CG3 > CG6

[0248] Regarding the effective aperture, the lens with the largest effective aperture can be the first lens (201). Here, the effective aperture is the average of the effective aperture on the object-side surface and the effective aperture on the sensor-side surface of each lens. The lens surface with the largest effective aperture can be the first surface (S1) of the first lens (201). The lens with the smallest effective aperture can be the seventh lens (207). The lens surface with the smallest effective aperture can be the fourteenth surface (S14) of the seventh lens (207). The effective apertures of the first to seventh lenses (201 to 207) can be greater than the diagonal length of the image sensor (300).

[0249] The effective aperture of each lens can satisfy any of the following conditions.

[0250] Condition 1: CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0251] Condition 2: CA_L1 > CA_L2 > CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0252] Condition 3: CA_L1, CA_L2, CA_L6 > CA_L3 > CA_L4, CA_L5, CA_L7

[0253] Condition 4: CA_L1, CA_L2, CA_L3, CA_L6 > CA_L4 > CA_L5, CA_L7

[0254] Condition 5: CA_L1, CA_L2, CA_L3, CA_L4, CA_L6 > CA_L5 > CA_L7

[0255] Condition 6: CA_L1, CA_L2 > CA_L6 > CA_L3, CA_L4, CA_L5, CA_L7

[0256] Condition 7: CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L6 > CA_L7

[0257] When describing the refractive index, the refractive indices of the second lens (202) and the fourth lens (204) can be the highest among the lenses and can exceed 1.6, for example, 1.65. Any one of the first lens (201), the fifth lens (205), and the sixth lens (206) can have the lowest 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) can be the lowest among the lenses and less than 1.6, such as less than 1.55. The difference between the maximum and minimum refractive index can be 0.1 or greater.

[0258] The refractive index of each lens can satisfy any of the following conditions.

[0259] Condition 1: n2, n3, n4, n7 > n1 = n5 = n6

[0260] Condition 2: n2 = n4 > n1, n3, n5, n6, n7

[0261] Condition 3: n2, n4, n7 > n3 > n1, n5, n6

[0262] Condition 4: n2, n4 > n7 > n1, n3, n5, n6

[0263] When comparing Abbe numbers, the Abbe numbers of the first lens (201), the fifth lens (205), and the sixth lens (206) can be the largest among the lenses, and can be 50 or greater. The Abbe numbers of the second lens (202) and the fourth lens (204) can be the smallest among the lenses, and can be 20 or less. The difference between the maximum refractive index and the minimum Abbe number can be 30 or greater.

[0264] The Abbe number of each lens can satisfy any of the following conditions.

[0265] Condition 1: v1 = v5 = v6 > v2, v3, v4, v7

[0266] Condition 2: v1, v3, v5, v6, v7 > v2 = v4

[0267] Condition 3: v1, v5, v6 > v3 > v2, v4, v7

[0268] Condition 4: v1, v3, v5, v6 > v7 > v2, v4

[0269] The focal lengths (F1, F4, F6) of the first, fourth, and sixth lenses (201, 204, 206) can have a positive (+) sign. The first, fourth, and sixth lenses (201, 204, 206) can have a positive (+) refractive power. The focal lengths (F2, F3, F5, F7) of the second, third, fifth, and seventh lenses (202, 203, 205, 207) can have a negative (-) sign. The second, third, fifth, and seventh lenses (202, 203, 205, 207) can have a negative (-) refractive power.

[0270] When comparing focal lengths as absolute values, the second lens (202) can have the largest focal length among the lenses, and can be 20 or larger as well as 40 or smaller. The sixth lens (206) can have the smallest focal length among the lenses, and the absolute value of the focal length of the sixth lens (206) can be greater than 5 and less than 8.

[0271] The absolute value of the focal length of each lens can satisfy any of the following conditions.

[0272] Condition 1: |f2|、|f7| > |f1| > |f3|、|f4|、|f5|、|f6|

[0273] Condition 2: |f2| > |f1|, |f3|, |f4|, |f5|, |f6|, |f7|

[0274] Condition 3: |f1|、|f2||f4||f5|、|f7| > |f3| > |f6|

[0275] Condition 4: |f1|、|f2|、|f7| > |f4| > |f3|、|f5|、|f6|

[0276] Condition 5: |f1|, |f2|, |f4|, |f7| > |f5| > |f3|, |f6|

[0277] Condition 6: |f1|, |f2|, |f3|, |f4|, |f5|, |f7| > |f6|

[0278] Condition 7: |f2| > |f7| > |f1|, |f3|, |f4|, |f5|, |f6|

[0279] The compound focal length (f_LG1) of the first lens group (LG1) can have a positive (+) sign. The first lens group (LG1) can have a positive (+) compound refractive power. The compound focal length (f_LG2) of the second lens group (LG2) can have a positive (+) sign. The second lens group (LG2) can have a positive (+) compound refractive power. The compound focal length (f_LG3) of the third lens group (LG3) can have a negative (-) sign. The third lens group (LG3) can have a negative (-) compound refractive power. The fourth lens group (LG4) can have a positive (+) focal length (f_LG4). The fourth lens group (LG4) can have a positive refractive power. This allows light entering from the object side to move away from the optical axis and then converge back towards the optical axis to form a stable optical path.

[0280] When comparing the absolute values ​​of the compound focal lengths of each of the first to fourth lens groups (LG1, LG2, LG3, LG4), the compound focal length of the second lens group (LG2) can be the largest, and the compound focal length of the third lens group (LG3) can be the smallest. The relative order of the compound focal lengths of the first to fourth lens groups (LG1, LG2, LG3, LG4) can satisfy the condition |f_LG2| > |f_LG1| > |f_LG4| > |f_LG3|.

[0281] The thickness (CT1) of the first lens (201) can have a difference of at least twice between the maximum and minimum thickness, for example, in the range of 2.5 to 3 times, wherein the center thickness (CT1) is the largest and the edge thickness (ET1) is the smallest. The thickness (T2) of the second lens (202) can be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 1 to 1.5 times the minimum thickness. The thickness (T3) of the third lens (203) can be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T4) of the fourth lens (204) can be the largest at the center and the smallest at the edge, wherein the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T5) of the fifth lens (205) can be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T6) of the sixth lens (206) can be the greatest at the center and the least at the edge, with the maximum thickness ranging from 2.5 to 3 times the minimum thickness. The thickness (T7) of the seventh lens (207) can be the least at the center and the greatest at the edge, with the maximum thickness ranging from 1 to 1.5 times the minimum thickness.

[0282] The thickness of each lens can satisfy any of the following conditions.

[0283] Condition 1: 2.5 < CT1 / ET1 < 3, 0.1 < ET1 / CT1 < 0.5

[0284] Condition 2: 0.5 < CT2 / ET2 < 1, 1 < ET2 / CT2 < 1.5

[0285] Condition 3: 0.1 < CT3 / ET3 < 0.5, 2.5 < ET3 / CT3 < 3

[0286] Condition 4: 2.5 < CT4 / ET4 < 3, 0.1 < ET4 / CT4 < 0.5

[0287] Condition 5: 0.1 < CT5 / ET5 < 0.5, 2.5 < ET5 / CT5 < 3

[0288] Condition 6: 2.5 < CT6 / ET6 < 3, 0.1 < ET6 / CT6 < 0.5

[0289] Condition 7: 0.5 < CT7 / ET7 < 1, 1 < ET7 / CT7 < 1.5

[0290] Condition 8: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0291] Among the gaps (G1-G6) between the lenses, the gap (LG1) between the first and second lenses (201, 202) can be the largest at the center and the smallest at the edge. The gap (LG2) between the second and third lenses (202, 203) can be the smallest at the center and the largest at the edge. The gap (LG3) between the third and fourth lenses (203, 204) can have the largest value at the center and the smallest value at the edge. The gap (G4) between the fourth and fifth lenses (204, 205) can have the largest value at the edge and the smallest value at the center. The fifth gap (G5) between the fifth and sixth lenses (205, 206) can have the smallest value at the center and the largest value at the edge. The sixth gap (G6) between the sixth and seventh lenses (206, 207) can have the smallest value at the center and the largest value at the edge.

[0292] Figure 18 This is a graph showing data regarding the aberration characteristics of the optical system according to the second embodiment operating in the first mode. Figure 19 It is a graph showing the aberration characteristics of the optical system according to the second embodiment operating in the second mode, and Figure 20It is a graph showing the aberration characteristics of the optical system according to the second embodiment operating in the third mode. Figure 18 , 19 Figure 20 shows graphs from left to right measuring spherical aberration (longitudinal spherical aberration), astigmatic field curves, and distortion. Figure 18 , 19 In Figure 20, the X-axis represents focal length (mm) and distortion percentage (%), and the Y-axis represents image height. Furthermore, the spherical aberration curve corresponds to light in the wavelength bands of approximately 435 nm, 486 nm, 546 nm, 587 nm, and 656 nm, while the astigmatism and distortion curves correspond to light in the wavelength band of approximately 546 nm. Figure 18 , 19 In the aberration diagram of 20, the closer the curve is to the Y-axis, the better the aberration correction performance is interpreted. The optical system (1100) according to the second embodiment shows that the measured values ​​are adjacent to the Y-axis in almost all regions. In other words, the optical system (1100) according to the second embodiment has improved resolution and can achieve good optical performance not only in the central region of the field of view (FOV) but also in the peripheral region.

[0293] The optical systems (1000, 1100) according to the first and second embodiments described above can satisfy at least one or more of the mathematical formulas described below. Therefore, the optical systems (1000, 1100) according to the first and second embodiments can have improved optical characteristics. For example, if the optical systems (1000, 1100) satisfy at least one mathematical formula, the optical systems (1000, 1100) can effectively control aberration characteristics, such as chromatic aberration and distortion aberration, and can have good optical performance not only in the central region of the field of view (FOV) but also in the peripheral region of the field of view (FOV). Furthermore, the optical systems (1000, 1100) can have improved resolution. Additionally, the thickness of the lens at the optical axis (OA) as described in the mathematical formulas and the spacing (gap) between adjacent lenses at the optical axis (OA) can be referenced to the first and second embodiments disclosed above.

[0294] [Mathematical Expression 1]

[0295] 3 < TD_LG2 / TD_LG3 < 8

[0296] Equation 1 establishes the relationship between the lengths (TD_LG2) of the second lens group (LG2) and the lengths (TD_LG3) of the third lens group (LG3) along the optical axis. Equation 1 is a condition used to reduce aberrations and improve optical performance. The second lens group (LG2) and the third lens group (LG3) satisfying Equation 1 can appropriately correct astigmatism and coma. Furthermore, they can reduce the overall length of the zoom optical system while maintaining an appropriate zoom ratio. In the first and second embodiments, Equation 1 can preferably satisfy 5 < TD_LG2 / TD_LG3 < 6.

[0297] [Mathematical Expression 2]

[0298] 10 < EFL(f)_wide < 15

[0299] In Equation 2, EFL(f)_wide is the total focal length of the optical system (1000, 1100) at the wide end. Equation 2 is a condition used to limit the performance of zoom optics. If the upper limit of Equation 2 is exceeded, it becomes difficult to ensure optical performance due to chromatic aberration, and the movement of each lens group increases significantly during zooming, making mechanical miniaturization challenging. If the lower limit of Equation 2 is not met, the overall sensitivity of the optical system increases, which is problematic. A zoom optics system that satisfies Equation 2 can practically achieve useful optical performance. In the first and second embodiments, Equation 2 preferably satisfies 11 < EFL(f)_wide < 13.

[0300] [Mathematical Expression 3]

[0301] 10 < BFL_wide < 15

[0302] In Equation 3, BFL is the optical axis distance from the wide end (wide) to the center of the sensor side of the last lens of the image sensor (300). When Equation 3 is satisfied, mounting space for the second optical path changing components (112, 212) used as reflectors can be ensured, and the assembly compatibility of the components can be improved through the gap between the image sensor (300) and the last lens, thereby enhancing the reliability of the connection. In the first and second embodiments, Equation 3 preferably satisfies 10 < BFL_wide < 12. If BFL is below the range of Equation 3, some light traveling toward the image sensor may not be able to penetrate to the image sensor, resulting in a reduction in resolution. If BFL_wide exceeds the range of Equation 3, stray light may enter, thereby degrading the aberration characteristics of the optical system.

[0303] [Mathematical Expression 4]

[0304] 20 < Ave_ABV < 40

[0305] In Equation 4, Ave_ABV is the average Abbe number of the lenses included in the optical system (1000, 1100). When Equation 4 is satisfied, the elements affecting chromatic aberration can be appropriately set to improve optical performance. In the first and second embodiments, Equation 4 can preferably satisfy 35 < Ave_ABV < 40.

[0306] [Mathematical Expression 5]

[0307] 1.5 < Ave_Ind < 1.7

[0308] In Equation 5, Ave_Ind is the average refractive index of the lenses included in the optical system (1000, 1100). When Equation 5 is satisfied, elements affecting chromatic aberration can be appropriately set to improve optical performance. In the first and second embodiments, Equation 5 can preferably satisfy 1.6 < Ave_Ind < 1.65.

[0309] [Mathematical Expression 6]

[0310] 10 < |f_LG2 / f_LG3| < 80

[0311] Equation 6 establishes 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). Equation 6 is a condition used to reduce aberrations and improve optical performance. The second lens group (LG2) and the third lens group (LG3) satisfying Equation 6 can appropriately correct astigmatism and coma. In the first and second embodiments, Equation 6 can preferably satisfy 12 < |f_LG2 / f_LG3| < 55.

[0312] [Mathematical Expression 7]

[0313] 5 < |f_LG3| < 10

[0314] In Equation 7, f_LG3 is the focal length of the third lens group (LG3). Equation 7 is a condition used to reduce aberrations and improve optical performance. In the first and second embodiments, Equation 7 can preferably satisfy 6 < |f_LG3| < 7.

[0315] [Mathematical Expression 8]

[0316] 3 < LG3_stroke < 10

[0317] Formula 8 sets the range of the stroke length (LG3_stroke) of the third lens group (LG3). If the upper limit of Formula 8 is exceeded, the stroke length of the third lens group (LG3) increases during focusing, which may make it difficult to miniaturize the optical system. If the lower limit of Formula 8 is not met, the focusing performance of the optical system may deteriorate. Formula 8 is preferably satisfied in the first and second embodiments, wherein 4 < LG3_stroke < 6.

[0318] [Mathematical Expression 9]

[0319] 5 < F1 < 20

[0320] In Equation 9, F1 is the focal length of the first lens (101, 201). When Equation 9 is satisfied, the optical system (1000, 1100) has a set field of view (FOV) and an appropriate focal length, and the field of view can be set large within an appropriate TTL range. If this value is below the lower limit of Equation 9, the effective aperture or TTL of the lens may become longer, potentially leading to an enlargement of the imaging lens system. If it exceeds the upper limit of Equation 9, the influence of the first lens (101, 201) is reduced throughout the optical system, thus requiring an increase in the refractive power of the lens, making it difficult to correct spherical aberration or distortion aberrations. In the first and second embodiments, Equation 9 preferably satisfies condition 10 < F1 < 15.

[0321] [Mathematical Expression 10]

[0322] 1 < CT1 < 5

[0323] In mathematical formula 10, CT1 is the center thickness of the first lens (101, 201). When mathematical formula 10 is satisfied, a miniaturized optical system (1000, 1100) can be realized. In the first and second embodiments, mathematical formula 10 preferably satisfies condition 1. <CT1 < 2。

[0324] [Mathematical Expression 11]

[0325] 20 < TTL < 50

[0326] In mathematical formula 11, TTL (total trajectory length) represents the distance (mm) along the optical axis (OA) from the center of the first surface (S1) of the first lens (101, 201) to the upper surface of the image sensor (300). In the first and second embodiments, mathematical formula 11 preferably satisfies condition 25 < TTL < 30.

[0327] [Mathematical Expression 12]

[0328] 5 < ImgH < 8

[0329] In Equation 12, ImgH represents the maximum diagonal length of the image sensor (300). Equation 12 allows setting the diagonal size (ImgH) of the image sensor (300) and provides an optical system capable of accommodating large-sized moving image sensors. In the first and second embodiments, Equation 12 may preferably satisfy the condition 5 < ImgH < 6.

[0330] [Mathematical Expression 13]

[0331] 2 < Fno_wide < 3

[0332] Equation 13 can define the range of Fno_wide in the optical system (1000, 1100). When Equation 13 is satisfied, an image with appropriate brightness can be provided, and the image sensor can receive a large amount of light. In the first and second embodiments, Equation 13 can preferably satisfy 2.5 < Fno_wide < 3.

[0333] [Mathematical Expression 14]

[0334] 10 < FOV_wide < 30

[0335] In mathematical expression 14, the field of view (FOV_wide) at the wide-angle position can be set. Mathematical expression 14 can provide a field of view suitable for a mobile optical system. In the first and second embodiments, FOV_wide preferably satisfies 20 < FOV_wide < 25.

[0336] [Mathematical Expression 15]

[0337] 2 < TTL / CA_max < 5

[0338] In Equation 15, CA_max represents the maximum effective aperture (mm) among the object-side and sensor-side surfaces of the multiple lenses, and TTL (total trajectory length) represents the distance (mm) along 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). Equation 15 establishes the relationship between the total optical axis length and the maximum effective aperture of the optical system, enabling the provision of an improved mobile optical system. In the first and second embodiments, Equation 15 can preferably satisfy condition 4 < TTL / CA_max < 3.5.

[0339] [Mathematical Expression 16]

[0340] 5 < TTL / ImgH < 8

[0341] In Equation 16, TTL (Total Trajectory Length) refers to the distance (mm) along the optical axis (OA) from the vertex of the first surface (S1) of the first lens to the upper surface of the image sensor (300), and ImgH refers to the maximum diagonal length of the image sensor (300). When Equation 16 is satisfied, the optical system (1000, 1100) can have a TTL suitable for moving the image sensor (300), thereby providing improved image quality. If the value is below the lower limit of Equation 2, the refractive power of the lens must be increased, making it difficult to correct spherical aberration or distortion aberration. If the value exceeds the upper limit of Equation 2, the effective focal length or TTL of the lens may become longer, leading to a problem of a larger imaging lens system. In the first and second embodiments, Equation 16 can preferably satisfy the condition 5 < TTL / ImgH < 5.5.

[0342] [Mathematical Expression 17]

[0343] 1 < EFL(F)_wide / ImgH < 4

[0344] In Equation 17, EFL(F)_wide is the total effective focal length of the optical system (1000, 1100) at wide angles, and ImgH is the maximum diagonal length of the image sensor (300). When Equation 17 is satisfied, the moving image sensor (300) can achieve improved aberration characteristics in terms of size. In the first and second embodiments, Equation 17 can preferably satisfy condition 2. <EFL(F)_wide / ImgH < 2.5。

[0345] [Mathematical Expression 18]

[0346] 0.1 < ΣCT / TTL < 1

[0347] Equation 18 establishes the relationship between the sum of the center thicknesses of the lenses (∑CT) and the distance (TTL) along the optical axis (OA) from the vertex of the first surface (S1) of the first lens to the upper surface of the image sensor (300). If the upper limit of Equation 18 is exceeded, the number of lenses increases, and the movement of the moving lens group in the optical system may become detrimental. If the lower limit of Equation 18 is not met, the focusing performance of the optical system may deteriorate. In the first and second embodiments, Equation 18 can preferably satisfy 0.1 < ΣCT / TTL < 0.5.

[0348] [Mathematical Expression 19]

[0349] 0.1 < ΣCG / TTL < 1

[0350] Equation 19 establishes a relationship between the sum of distances between adjacent lenses (∑CG) and the distance (TTL) along the optical axis (OA) from the vertex of the first surface (S1) of the first lens to the upper surface of the image sensor (300). If the upper limit of Equation 19 is exceeded, the displacement distance of the movable lens group in the lens optics system increases, which may cause increased current consumption during focusing operations. If the value is below the lower limit of Equation 19, the focusing performance of the optical system may deteriorate. In the first and second embodiments, Equation 19 may preferably satisfy the condition 0.1 < ΣCG / TTL < 0.5.

[0351] [Mathematical Expression 20]

[0352] 1 < ΣCT / ΣCG < 5

[0353] Equation 20 establishes the relationship between the sum of the center thicknesses of the lenses (∑CT) and the sum of the intervals between adjacent lenses (∑CT). If the upper limit of Equation 20 is exceeded, the number of lenses increases, and the movement of movable lens groups in the optical system may become detrimental. If the value is below the lower limit of Equation 20, focusing performance may deteriorate. In the first and second embodiments, Equation 20 can preferably satisfy condition 1 < ΣCT / ΣCG < 2.

[0354] [Mathematical Expression 21]

[0355] 1 < CA_max / CA_min < 3

[0356] In Equation 21, CA_max represents the maximum effective aperture between the object-side surface of the lens and the sensor-side surface, and CA_min represents the minimum effective aperture between the object-side surface of the lens and the sensor-side surface. When Equation 21 is satisfied, the optical system can maintain optical performance while setting dimensions for slim and compact structures. In the first and second embodiments, Equation 21 can preferably satisfy condition 1 < CA_max / CA_min < 1.5.

[0357] [Mathematical Expression 22]

[0358] 1 < CA_max / ImgH < 5

[0359] In Equation 22, CA_max represents the maximum effective diameter between the object-side surface and the sensor-side surface of the lens, and ImgH represents the maximum diagonal length of the image sensor (300). When Equation 22 is satisfied, the optical system can maintain good optical performance and can be sized for slim and compact structures. In the first and second embodiments, Equation 22 can preferably satisfy 1 < CA_max / ImgH < 1.5.

[0360] [Mathematical Expression 23]

[0361] 0.1 < CA_min / ImgH < 1

[0362] In Equation 23, CA_min represents the minimum effective focal length between the object-side surface of the lens and the sensor-side surface, and ImgH represents the maximum diagonal length of the image sensor (300). When Equation 23 is satisfied, the optical system can maintain good optical performance and can be sized for slim and compact structures. In the first and second embodiments, Equation 23 can preferably satisfy 0.5 < CA_min / ImgH < 1.

[0363] [Mathematical Expression 24]

[0364] 15 < L1R1 + L6R1 < 20

[0365] In Equation 24, L1R1 is the radius of curvature of the object-side surface of the first lens (101, 201) of the first lens group (LG1) closest to the object side, and L6R1 is the radius of curvature of the object-side surface of the sixth lens (106, 206) of the fourth lens group (LG4) closest to the object side. When Equation 24 is satisfied, the optical system (1000, 1100) has a set field of view and an appropriate focal length, and the field of view can be set to a large value within an appropriate TTL range. If the value is below the lower limit of Equation 24, the effective length or TTL of the lens may become longer, resulting in a problem of the imaging lens system becoming larger. If the value exceeds the upper limit of Equation 24, the refractive power of the lens may have to be increased, making it difficult to correct spherical aberration or distortion aberration. In the first and second embodiments, Equation 24 may preferably satisfy condition 15 < L1R1 + L6R1 < 17.

[0366] [Mathematical Expression 25]

[0367] 0.2 < BFL / TTL < 0.5

[0368] In Equation 25, BFL is the optical axis distance from the image sensor (300) to the center of the sensor-side surface of the last lens, and TTL (Total Track Length) is 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) along the optical axis (OA). When Equation 25 is satisfied, space can be ensured within the optical system (1000, 1100) to accommodate the optical path control components, thereby enabling miniaturization of the overall size of the optical system. If the value is below the lower limit of Equation 25, interference occurs between the mirror and the image sensor, and if the value exceeds the upper limit of Equation 25, the optical system becomes larger. In the first and second embodiments, Equation 25 can preferably satisfy 0.3 < BFL / TTL < 0.4.

[0369] [Mathematical Expression 26]

[0370] In Equation 26, Z can represent the distance from any point on the aspherical surface to the vertex of the aspherical surface along the optical axis. Y can represent the distance from any point on the aspherical surface to the optical axis along a direction perpendicular to the optical axis. c can represent the curvature of the lens, and K can represent the conic constant (a constant for a conic section). Furthermore, A, B, C, D, E, and F can represent aspherical constants.

[0371] The optical systems (1000, 1100) according to the first and second embodiments can satisfy at least one or more of mathematical formulas 1 to 26, in which case the optical systems (1000, 1100) can have improved optical characteristics. Specifically, when the optical systems (1000, 1100) satisfy at least one or more of mathematical formulas 1 to 26, the optical systems (1000, 1100) have improved resolution and can improve aberration and distortion characteristics. Furthermore, the optical systems (1000, 1100) can ensure the required back focal length (BFL) for the image sensor (260), compensate for optical characteristic degradation due to temperature changes, and minimize the distance between the last lens and the image sensor (260), thereby achieving good optical performance in both the central and peripheral regions of the field of view (FOV).

[0372] Table 7

[0373] Table 7 shows the results of mathematical expressions 1 to 26 for the optical systems (1000, 1100) in the first and second embodiments described above. 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 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 equations 1 to 26. As a result, the optical systems (1000, 1100) can have good optical performance and excellent optical characteristics in the center and peripheral regions of the field of view (FOV).

[0374] Figure 22 This is an example of a mobile terminal having an optical system according to this embodiment. For example... Figure 22 As shown, the mobile terminal (1500) may include a camera module (1520), a flash module (1530), and an autofocus device (1510) disposed on one side or the rear side. Here, the autofocus device (1510) may include a light-emitting layer containing the above-described surface-emitting laser device and a light-receiving unit.

[0375] The flash module (1530) may include an emitter that emits light internally. The flash module (1530) may be operated via camera operation of a mobile terminal or via user control. The camera module (1520) may include image capture and autofocus functions. For example, the camera module (1520) may include autofocus functionality using images.

[0376] The autofocus device (1510) may include an autofocus function using a laser. The autofocus device (1510) can be used primarily under conditions where the autofocus function using the image from the camera module (1520) is degraded. Furthermore, although not shown in the figures, at least one camera module may be positioned in front of the mobile terminal (1500). At least one camera module within the mobile terminal may have the aforementioned telephoto-type folding optical system.

[0377] The optical system or camera module according to embodiments of this disclosure can be applied to lens assemblies according to various embodiments, such as electronic devices equipped with image sensors. Lens assemblies according to exemplary embodiments can be applied to various electronic devices, such as digital cameras, interchangeable lens cameras, camcorders, mobile phone cameras, cameras for small mobile devices, VR, AR, drones, or manned / unmanned aerial vehicles.

[0378] The features, structures, and effects described in the above embodiments are included in at least one embodiment of this disclosure, and are not necessarily limited to a single embodiment. Furthermore, the features, structures, and effects shown in each embodiment can be combined or modified by those skilled in the art in other embodiments. Therefore, such combinations and modifications should be interpreted as falling within the scope of this disclosure.

[0379] Furthermore, although embodiments have been described above, they are merely examples and not intended to limit the scope of this disclosure. Those skilled in the art will understand that various modifications and applications not shown above are possible without departing from the essential characteristics of the embodiments. For example, each component specifically illustrated in the embodiments may be modified and implemented. Moreover, differences associated with such modifications and applications should be interpreted as falling within the scope of this disclosure as defined in the appended claims.

Claims

1. An optical system comprising a first lens group to a fourth lens group arranged along an optical axis, wherein, The first lens group has positive (+) refractive power, the second lens group has positive (+) refractive power, the third lens group has negative (-) refractive power, and the fourth lens group has positive (+) refractive power, and the first lens group to the fourth lens group include at least one lens with negative (-) refractive power.

2. The optical system according to claim 1, wherein, The first to the third lens groups are movable groups, and the fourth lens group is a fixed group.

3. The optical system according to claim 1, wherein, On the optical axis, the object-side surface of the lens closest to the object side in the first lens group has a convex shape, and on the optical axis, the object-side surface of the lens closest to the object side in the fourth lens group also has a convex shape.

4. The optical system according to claim 1, wherein, When the optical system is operated from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the third lens group increases, and the distance between the third lens group and the fourth lens group decreases.

5. The optical system according to claim 1, wherein, When the optical system operates from the wide-angle end to the telephoto end, the travel length of the third lens group is greater than the travel length of the first lens group and greater than the travel length of the second lens group.

6. The optical system according to claim 1, wherein, The first lens group includes the first lens and the second lens, the second lens group includes the third lens and the fourth lens, the third lens group includes the fifth lens having negative (-) refractive power, and the fourth lens group includes the sixth lens and the seventh lens.

7. The optical system according to claim 6, 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 sixth lens has positive (+) refractive power, and the seventh lens has negative (-) refractive power.

8. The optical system according to claim 1, wherein, The first optical path control component is disposed on the object side of the first lens group, and the second optical path control component is disposed between the fourth lens group and the image sensor.

9. The optical system according to claim 8, wherein, The first optical path control component is a prism lens, and the second optical path control component is a reflector.

10. An optical system comprising a first lens to a seventh lens 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. The first and second lenses form a movable first lens group, the third and fourth lenses form a movable second lens group, the fifth lens is a movable third lens group, and the sixth and seventh lenses are a fixed fourth lens group.

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