Optical system and camera module

Abstract

An optical system according to an embodiment of the present application includes first to fourth lens groups arranged along an optical axis, wherein the first lens group has a positive (+) refractive power, the second lens group has a negative (-) refractive power, the third lens group has a positive (+) refractive power, the fourth lens group has a positive (+) refractive power, a prism lens is arranged closest to an object side in the first lens group, the prism lens includes an entrance surface, a reflection surface, and an exit surface, and the entrance surface or the exit surface of the prism lens has a convex shape.

Description

Technical Field

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

[0002] Camera modules perform the function of capturing images or videos of objects and are installed in a variety of applications. In particular, camera modules are manufactured in ultra-small sizes and used in portable devices such as smartphones, tablet PCs, and laptops, as well as 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 that forms an image and an image sensor that converts the formed image into an electrical signal. In this case, the camera module can perform an autofocus (AF) function that automatically adjusts the gap between the image sensor and the imaging lens to align the lens's focal length, and can perform a zoom function to increase or decrease the magnification of distant objects and capture them through a zoom lens. Additionally, the camera module employs image stabilization (IS) technology to correct or prevent image shake caused by camera movement due to unstable fixtures or user movement.

[0004] The most important component for these camera modules to acquire images is the imaging lens that forms the image. Recently, there has been increasing interest in high performance, such as high definition and high resolution, and optical systems that include multiple lenses to achieve this are being studied.

[0005] For example, research is underway to develop high-performance optical systems using multiple imaging lenses with positive (+) or negative (-) refractive power. However, when multiple lenses are included, the overall optical system can become larger, and there are challenges in deriving excellent optical and aberration characteristics.

[0006] Furthermore, optical systems comprising 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 surface of the lens adjacent to the object can increase. Consequently, the overall thickness and length of devices such as smartphones with optical systems may increase, and miniaturization becomes difficult.

[0007] Camera modules for close-up photography have a shorter TTL than conventional camera modules. As another example, camera modules for long-distance photography have a longer TTL than conventional camera modules. However, due to the limited installation space for camera modules in portable terminals, it is difficult to install camera modules for long-distance photography or camera modules capable of adjusting image magnification (zoom camera modules). Therefore, a new optical system is needed to solve the aforementioned problems. Summary of the Invention Technical issues

[0008] This embodiment aims to provide a zoom optical system and camera module with improved optical characteristics.

[0009] This embodiment can provide an optical system that can be implemented in a small and compact manner.

[0010] This embodiment can provide an optical system in which at least one of a plurality of lenses adjacent to the object side or to the exterior of the terminal device has different lengths along a first direction and a second direction. That is, at least one or more of the lenses can provide an optical system with different lengths in two mutually orthogonal directions.

[0011] The purpose of this embodiment is to provide an optical system suitable for folding cameras or telephoto lenses with a thin thickness or height. Technical solution

[0012] To solve the above-mentioned technical problems, an optical system according to an embodiment of the present invention includes: a first to a fifth lens group arranged along an optical axis, wherein the first lens group has positive (+) refractive power, the second lens group has negative (-) refractive power, the third lens group has positive (+) refractive power, the fourth lens group has negative (-) refractive power, and the fifth lens group has positive (+) refractive power, wherein the first lens group includes a prism lens, wherein the first and second lens groups are fixed groups, and wherein the third, fourth, and fifth lens groups are movable groups.

[0013] The travel length of the third lens group can be greater than that of the fourth lens group.

[0014] In the fifth lens group, the lens closest to the sensor side can have a shape in which two of its surfaces are convex along the optical axis.

[0015] In the first lens group, the lens positioned closest to the object side can have a meniscus shape that protrudes from the optical axis to the object side.

[0016] The first lens group includes a first lens with positive (+) refractive power and a second lens as a prism lens. The second lens group may include a third lens with negative (-) refractive power and a fourth lens with negative (-) refractive power.

[0017] The third lens group includes a fifth lens with positive (+) refractive power and a sixth lens with negative (-) refractive power; the fourth lens group may include a seventh lens with positive (+) refractive power and an eighth lens with negative (-) refractive power; and the fifth lens group may include a ninth lens with positive (+) refractive power.

[0018] Each of the second to fourth lens groups may include two lenses with different refractive powers.

[0019] Among the first to ninth lenses, the effective diameter of the first lens can be the largest.

[0020] The following conditional expression can be satisfied. <Conditional expression> 0.1 < TD_LG2 / TD_LG3 < 0.5 (In the conditional expression, TD_LG2 is the length of the second lens group in the optical axis direction, and TD_LG3 is the length of the third lens group in the optical axis direction).

[0021] The following conditional expression can be satisfied: <conditional expression> 15 < F1 < 65 (in the conditional expression, F1 is the focal length of the first lens).

[0022] To solve the above-mentioned technical problems, an optical system according to an embodiment of the present invention includes: a first to a fifth lens group arranged along an optical axis, wherein the first lens group has positive (+) refractive power, wherein the second lens group has negative (-) refractive power, wherein the third lens group has positive (+) refractive power, wherein the fourth lens group has negative (-) refractive power, wherein the fifth lens group has positive (+) refractive power, wherein the first lens group includes a prism lens, and wherein the second to fourth lens groups each include two lenses with different refractive powers.

[0023] The first and second lens groups can be fixed groups, while the third, fourth, and fifth lens groups can be movable groups.

[0024] The travel length of the third lens group can be greater than that of the fourth lens group.

[0025] Among the first to ninth lenses, the first lens has the largest effective diameter, and among the first to ninth lenses, the seventh lens can have the smallest effective diameter.

[0026] The following conditional expression can be satisfied. <Conditional expression> 4 < TTL / ImgH < 6 (In the conditional expression, TTL is the optical axis distance from the vertex of the object-side surface of the first lens to the image surface of the image sensor, and ImgH is the maximum diagonal length of the image sensor). Beneficial effects

[0027] The optical system and camera module according to this embodiment have various magnifications and can have excellent optical characteristics when providing various magnifications. In detail, the embodiment controls the movement distance of a lens group having a set number of lenses, a lens group having a set refractive power, a plurality of lenses having a set shape and focal length, etc., to have various magnifications and can provide an autofocus (AF) function for the subject.

[0028] Furthermore, each of the multiple lens groups can correct for aberration characteristics or complement each other for aberration characteristics that change due to movement. Therefore, the optical system according to the embodiment can minimize or prevent changes in chromatic aberration and aberration characteristics that occur with changes in magnification.

[0029] Furthermore, the effective focal length (EFL) can be controlled by moving only some of the multiple lens groups, and the movement distance of the moving lens groups can be minimized. Therefore, this embodiment can significantly reduce the movement distance of the lens groups when the magnification changes, and can minimize the power consumption required when moving the lens groups.

[0030] Furthermore, the optical system according to this embodiment has enhanced optical characteristics and can have a large back focal length (BFL), thereby providing an optical system suitable for folding camera modules. Attached Figure Description

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

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

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

[0034] Figure 4 This is a table showing the aspherical coefficients of lenses in an optical system according to a first embodiment of the present invention.

[0035] Figure 5 It is a graph showing the aberration characteristics of the optical system according to the first embodiment of the present invention operating in the first mode.

[0036] Figure 6 This is a graph showing the aberration characteristics of the optical system according to the first embodiment of the present invention operating in the second mode.

[0037] Figure 7 This is a graph showing the aberration characteristics of the optical system according to the first embodiment of the present invention operating in the third mode.

[0038] Figure 8 This is a configuration diagram of an optical system according to a second embodiment of the present invention operating in the first mode.

[0039] Figure 9This is a configuration diagram of an optical system according to a second embodiment of the present invention operating in the second mode.

[0040] Figure 10 This is a configuration diagram of an optical system according to a second embodiment of the present invention operating in the third mode.

[0041] Figure 11 This is a table showing the aspherical coefficients of the lenses in the optical system according to the second embodiment.

[0042] Figure 12 It is a graph showing the aberration characteristics of the optical system according to the second embodiment operating in the first mode.

[0043] Figure 13 It is a graph showing the aberration characteristics of the optical system according to the second embodiment operating in the second mode.

[0044] Figure 14 It is a graph showing the aberration characteristics of the optical system according to the second embodiment operating in the third mode.

[0045] Figure 15 This is a diagram showing the configuration of the optical system according to the third embodiment operating in the first mode.

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

[0047] Figure 17 This is a diagram showing the configuration of the optical system according to the third embodiment operating in the third mode.

[0048] Figure 18 This is a table showing the aspherical coefficients of the lenses in the optical system according to the third embodiment.

[0049] Figure 19 It is a graph showing the aberration characteristics of an optical system according to a third embodiment of the present invention operating in the first mode.

[0050] Figure 20 This is a graph showing the aberration characteristics of an optical system according to a third embodiment of the present invention operating in the second mode.

[0051] Figure 21 This is a graph showing the aberration characteristics of an optical system according to a third embodiment of the present invention operating in the third mode.

[0052] Figure 22 This is a diagram illustrating the D-cut lens of the present invention.

[0053] Figure 23 This is an example of a portable terminal having an optical system according to this embodiment. Detailed Implementation

[0054] Preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings.

[0055] However, the technical concept of the present invention is not limited to the embodiments to be described, but can be implemented in various forms, and one or more constituent elements can be selectively combined or substituted among the embodiments within the scope of the technical concept of the present invention.

[0056] Furthermore, unless explicitly defined and described, the terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as meanings that can be normally understood by those skilled in the art, and common terms such as those defined in dictionaries may be interpreted in consideration of the meaning in the context of the relevant art.

[0057] Furthermore, the terminology used in this specification is for describing embodiments and is not intended to limit the invention. In this specification, unless specifically stated in the phrase, the singular form may include the plural form, and when described as “at least one (or more than one) of A, B, and C,” it may include one or more of all combinations that can be combined with A, B, and C.

[0058] In addition, when describing the components of embodiments of the present invention, terms such as first, second, A, B, (a) and (b) may be used.

[0059] These terms are intended only to distinguish components from other components, and the terms do not restrict the nature, order, or sequence of components.

[0060] Furthermore, when a component is described as being “connected,” “coupled,” or “interconnected” to another component, the component is not only directly connected, coupled, or interconnected to the other component, but may also include cases where the component is “connected,” “coupled,” or “interconnected” due to another component between other components.

[0061] Additionally, when described as being formed or disposed "above" or "below" in each component, "above" or "below" indicates that it includes not only the case where two components are in direct contact, but also the case where one or more other components are formed or disposed between the two components. Furthermore, when expressed as "above" or "below," it can include not only the meaning of an upward direction based on a component, but also the meaning of a downward direction based on a component.

[0062] In the description of this invention, "object-side surface" can refer to the surface of the lens facing the object side (object side) relative to the optical axis direction OA, and "sensor-side surface" can refer to the surface of the lens facing the imaging surface (image sensor) relative to the optical axis. "Object-side surface" can be "object side," and "sensor-side surface" can be "image side." A convex surface of the lens can refer to a convex shape in the optical axis or paraxial region, and a concave surface of the lens can refer to a concave shape in the optical axis or paraxial region. The radius of curvature, center thickness, and optical axis clearance between lenses described in the lens data sheet can represent values ​​on the optical axis (unit: mm). The vertical direction can refer to a direction perpendicular to the optical axis, and the end of the 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, etc. The aforementioned paraxial region refers to a very narrow region near the optical axis, and a region where the distance of light falling from the optical axis direction OA is almost zero. In the following text, the meaning of the optical axis direction can include the center of each lens or a very narrow region near the optical axis direction.

[0063] The optical axis direction OA can refer to the central axis of the path along which light incident from the first direction (Y-axis direction) is bent by prism lenses 101, 201 and 301 in the second direction (X-axis direction).

[0064] The optical systems 1000, 1100, and 1200 according to the first to third embodiments may include multiple lens groups. Specifically, the optical systems 1000, 1100, and 1200 may include multiple lens groups, each lens group including at least one lens. For example, the optical systems 1000, 1100, and 1200 may include a first lens group LG1, a second lens group LG2, a third lens group LG3, a fourth lens group LG4, a fifth lens group LG5, and an image sensor 400, arranged sequentially from the object side toward the image sensor.

[0065] Each of the first to fifth lens groups LG1, LG2, LG3, LG4, and LG5 can have a positive (+) or negative (-) refractive power. The first lens group LG1 and the second lens group LG2 can have refractive powers with different signs. For example, the first lens group LG1 can have a positive (+) refractive power, and the second lens group LG2 can have a negative (-) refractive power. The second lens group LG2 and the third lens group LG3 can have refractive powers with different signs. For example, the second lens group LG2 can have a negative (-) refractive power, and the third lens group LG3 can have a positive (+) refractive power. The third lens group LG3 and the fourth lens group LG4 can have refractive powers with different signs. For example, the third lens group LG3 can have a positive (+) refractive power, and the fourth lens group LG4 can have a negative (-) refractive power. The fourth lens group LG4 and the fifth lens group LG5 can have refractive powers with different signs. For example, the fourth lens group LG4 can have a negative (-) refractive power, and the fifth lens group LG5 can have a positive (+) refractive power.

[0066] At least one of the first to fifth lens groups LG1, LG2, LG3, LG4, and LG5 can be movably disposed along the optical axis direction OA. By configuring at least one lens group as a movable group, the travel distance can be reduced. Specifically, at least two of the plurality of lens groups LG1, LG2, LG3, LG4, and LG5 can be movable, and the remaining lens groups can be fixed. In the first and second embodiments, the first lens group LG1, the second lens group LG2, and the fifth lens group LG5 can be disposed in fixed positions, and the third lens group LG3 and the fourth lens group LG4 can be configured to be movable along the optical axis direction OA. In the first and second embodiments, the first lens group LG1 and the second lens group LG2 can be disposed in fixed positions, and the third lens group LG3, the fourth lens group LG4, and the fifth lens group LG5 can be configured to be movable along the optical axis direction OA.

[0067] The first lens group LG1 may include multiple lenses. The first lens group LG1 may include two lenses. The first lens group LG1 may include prism lenses, which are second lenses 102, 202, and 302.

[0068] Optical systems 1000, 1100, and 1200 can reduce their thickness in a first direction (Y-axis direction) perpendicular to the optical axis direction OA (X-axis direction) of optical systems 1000, 1100, and 1200 by including a second lens 102 as a prism lens. When optical systems 1000, 1100, and 1200 do not include a prism lens, multiple lenses can be arranged to extend in a direction perpendicular to the surface of the optical device within the optical apparatus including optical systems 1000, 1100, and 1200.

[0069] Therefore, multiple lenses have a high height in the direction perpendicular to the surface of the optical device, and it may be difficult to form an optical device with an ultra-thin thickness. Prismatic lenses can change the direction of light incident in the direction perpendicular to the surface of the optical device to a direction parallel to the surface of the optical device. That is, multiple lenses included in optical systems 1000, 1100, and 1200 can be arranged to extend in the direction parallel to the surface of the optical device, and the optical device can be formed with a thin thickness.

[0070] A driving member (not shown) can be connected to the prism lens. The driving member may include at least one actuator. For example, the driving member may include at least one of a voice coil motor (VCM), a piezoelectric device, a shape memory alloy, or a MEMS device as an actuator. The actuator can use the driving force of the actuator to move the prism lens. For example, the driving member can tilt the prism lens along a first axis (Y-axis) or a second axis (X-axis) to control the prism lens. Therefore, the camera module 1520 can correct for shake.

[0071] It includes a detection unit (not shown) for detecting jitter in the camera module 1520, and the detection unit can detect rotational and positional changes applied to the camera module 1520. The detection unit may include at least one of a sensor for detecting changes in angular velocity (e.g., a gyroscope sensor) and an accelerometer sensor for detecting changes in acceleration.

[0072] The camera module 1520 can control the movement of the prism lens via control signals. Specifically, when shaking occurs in the camera module 1520, information about the shaking, such as the degree of rotation and positional change of the sensor, can be detected, and shaking compensation can be performed.

[0073] Therefore, the camera module 1520 according to the embodiment can effectively compensate for shake caused by rotation and shake caused by positional changes when photographing subjects located at infinity or close range (macro). Thus, the camera module 1520 can have enhanced optical characteristics.

[0074] The plurality of lenses included in the first lens group LG1 may have a set gap. In detail, the gap between the plurality of lenses included in the first lens group LG1 may be constant and will not change in the operating mode, as will be described later. For example, the gap between the first lenses 101, 201 and 301 and the second lenses 102, 202 and 302 may be constant and will not change in the operating mode, as will be described later.

[0075] The second lens group LG2 may include multiple lenses. The second lens group LG2 may include two or more lenses. The multiple lenses included in the second lens group LG2 may have a predetermined interval. Specifically, the gap between the multiple lenses included in the second lens group LG2 may be constant and will not change in operating modes, as will be described later. For example, the gap between the third lenses 103, 203, and 303 and the fourth lenses 104, 204, and 304 may be constant and will not change in operating modes, as will be described later.

[0076] The third lens group LG3 may include multiple lenses. Specifically, the third lens group LG3 may include two or more lenses with opposite refractive powers. For example, the third lens group LG3 may include two lenses.

[0077] The multiple lenses included in the third lens group LG3 can have a set gap. Specifically, the gap between the multiple lenses included in the third lens group LG3 can be constant and will not change in operating modes, as will be described later. For example, the gap between the fifth lenses 105, 205, and 305 and the sixth lenses 106, 206, and 306 can be constant and will not change in operating modes, as will be described later.

[0078] The fourth lens group LG4 may include multiple lenses. 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 gap. Specifically, the gap between the multiple lenses included in the fourth lens group LG4 can be constant and does not change in operating modes, as will be described later. For example, the gap between the seventh lenses 107, 207, and 307 and the eighth lenses 108, 208, and 308 can be constant and does not change in operating modes, as will be described later.

[0080] The fifth lens group LG5 may include a single lens. Specifically, the fifth lens group LG5 may include one or more lenses having positive (+) refractive power. For example, the fifth lens group LG5 may include a single lens.

[0081] In other words, optical systems 1000, 1100, and 1200 may include multiple lens groups LG1, LG2, LG3, LG4, and LG5 arranged sequentially from the object side toward the sensor, as well as an image sensor 400. Furthermore, optical systems 1000, 1100, and 1200 may include multiple lenses included in lens groups LG1, LG2, LG3, LG4, and LG5, such as first lenses 101, 201, and 301; second lenses 102, 202, and 302; third lenses 103, 203, and 303; fourth lenses 104, 204, and 304; fifth lenses 105, 205, and 305; sixth lenses 106, 206, and 306; seventh lenses 107, 207, and 307; eighth lenses 108, 208, and 308; and ninth lenses 109, 209, and 309.

[0082] The first lens group LG1 may include first lenses 101, 201, and 301 and second lenses 102, 202, and 302. The second lens group LG2 may include third lenses 103, 203, and 303 and fourth lenses 104, 204, and 304. The third lens group LG3 may include fifth lenses 105, 205, and 305 and sixth lenses 106, 206, and 306. The fourth lens group LG4 may include seventh lenses 107, 207, and 307 and eighth lenses 108, 208, and 308. The fifth lens group LG5 may include ninth lenses 109, 209, and 309. The first lenses 101, 201, and 301 to the ninth lenses 109, 209, and 309, and the image sensor 400 may be sequentially arranged from the object side of the optical systems 1000, 1100, and 1200 toward the sensor direction.

[0083] Each of the multiple lenses may include an effective region and an ineffective region. The effective region may be the area through which light incident on each of the first lenses 101, 201, and 301 to the ninth lenses 109, 209, and 309 passes. In other words, the effective region may be the area where incident light is refracted to achieve optical properties.

[0084] The invalid region can be located around the valid region. The invalid region can be a region where no light is incident. In other words, the invalid region can be a region unrelated to optical properties. Additionally, the invalid region can be a region fixed to a lens barrel (not shown) that houses the lens.

[0085] refer to Figure 22In the optical systems 1000, 1100, and 1200 according to the first to third embodiments, at least one lens in the first lens 101, 201, and 301 to the ninth lens 109, 209, and 309 may be subjected to D-cutting technology. When D-cutting technology is applied, a portion of the effective diameter or rib of the lens may be cut to reduce the height of the entire optical system. Here, the height of the entire optical system may represent the length in a direction perpendicular to the optical axis, other than TTL. The D-cut lens may have a non-circular shape, and the length A in the first direction (Y-axis direction) and the length B in the second direction (X-axis direction) may be different.

[0086] Image sensor 400 can detect light. Image sensor 400 can detect light that has passed sequentially through multiple lenses (e.g., from first lenses 101, 201, and 301 to ninth lenses 109, 209, and 309). Image sensor 400 may include a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS).

[0087] Optical systems 1000, 1100, and 1200 may also include a filter 500. The filter 500 may be disposed between the plurality of lenses and the image sensor 400. The filter 500 may be disposed between the image sensor 400 and the fifth lens group LG5, which is closest to the image sensor 400 among the plurality of lens groups LG1, LG2, LG3, LG4, and LG5. For example, the filter 500 may be disposed between the last lens of the fifth lens group LG5, which is closest to the image sensor 400, and the image sensor 400.

[0088] The filter 500 may include at least one of an optical filter, such as an infrared filter, and a cover glass. The filter 500 allows light of a defined wavelength band to pass through and filters light of different wavelength bands. When the filter 500 includes an infrared filter, it can block radiant heat emitted from external light from being transferred to the image sensor 400. Additionally, the filter 500 can transmit visible light and reflect infrared light.

[0089] Optical systems 1000, 1100, and 1200 may include apertures (not shown). The apertures can control the amount of light incident on optical systems 1000, 1100, and 1200.

[0090] An aperture stop can be positioned between lens groups. An aperture stop can be positioned between the second lens group LG2 and the third lens group LG3. An aperture stop can be positioned on the sensor side of the fourth lenses 104, 204, and 304, which are positioned closest to the second lens group LG2. An aperture stop can be positioned on the object side of the fifth lenses 105, 205, and 305, which are positioned closest to the object side of the third lens group LG3.

[0091] An aperture stop can be located in front of the first lenses 101, 201, and 301, or it can be positioned between two lenses selected from the first lenses 101, 201, and 301 to the ninth lenses 109, 209, and 309. For example, an aperture stop can be positioned between the fourth lenses 104, 204, and 304 and the fifth lenses 105, 205, and 305. Additionally, at least one lens selected from the first lenses 101, 201, and 301 to the ninth lenses 109, 209, and 309 can be used as an aperture stop. For example, the object-side surface or sensor-side surface of one lens selected from the first lenses 101, 201, and 301 to the ninth lenses 109, 209, and 309 can be used as an aperture stop for controlling the amount of light.

[0092] An optical system according to a first embodiment of the present invention will be described.

[0093] Figure 1 This is a configuration diagram of an optical system according to a first embodiment of the present invention operating in a first mode; Figure 2 This is a configuration diagram of an optical system according to a first embodiment of the present invention operating in a second mode; Figure 3 This is a configuration diagram of an optical system according to a first embodiment of the present invention operating in a third mode; Figure 4 This is a table showing the aspherical coefficients of lenses in an optical system according to a first embodiment of the present invention; Figure 5 It is a graph showing the aberration characteristics of the optical system according to the first embodiment of the present invention operating in the first mode; Figure 6 It is a graph showing data on the aberration characteristics of the optical system according to the first embodiment of the present invention operating in the second mode; and Figure 7 This is a graph showing the aberration characteristics of the optical system according to the first embodiment of the present invention operating in the third mode.

[0094] refer to Figures 1 to 3 The optical system 1000 includes a lens unit, which may include a first lens 101 to a ninth lens 109. The first to ninth lenses 101-109 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 to ninth lenses 101-109 and the filter 500 and be incident on the image sensor 400.

[0095] The first lens 101 can be positioned closest to the object side. The first lens 101 can also be positioned furthest from the sensor side. The first lens 101 can have positive (+) refractive power in the optical axis direction OA. The first lens 101 can comprise plastic or glass material, and can be, for example, plastic material.

[0096] The first surface S1 on the object side of the first lens 101 may be convex relative to the optical axis direction OA, and the second surface S2 on the sensor side may be concave. The first lens 101 may have a meniscus shape in which the object side is convex. The first lens 101 may have a meniscus shape in which the sensor side is concave. The first lens 101 may have an aspherical surface. The aspherical coefficients of the first and second surfaces S1 and S2 may be provided as follows: Figure 4 L1S1 and L1S2 in the image. The first lens 101 can be a D-cut lens.

[0097] The first surface S1 of the first lens 101 can be configured such that there is no critical point at the end of the effective region from the optical axis. The second surface S2 of the first lens 101 can have a critical point at the end of the effective region from the optical axis. When the second surface S2 has a critical point, it can be located in the range of 85% to 95%, preferably 90% to 95%, of the effective radius from the optical axis. The critical point of the second surface S2 can be located in the range of 3.5 mm to 5.0 mm, preferably 4.0 mm to 4.5 mm from the optical axis. The critical point of the second surface S2 is the point where the sign of the gradient value relative to the optical axis and in the direction perpendicular to the optical axis changes from positive (+) to negative (-) or from negative (-) to positive (+), and can also represent a point where the gradient value is 0. In addition, the critical point of the second surface S2 can be a point where the slope of the tangent through the lens surface increases and then decreases, or a point where the slope decreases and then increases.

[0098] The second lens 102 can be disposed as a second lens starting from the object side. The second lens 102 can also be disposed as an eighth lens starting from the sensor side. The second lens 102 can be disposed between the first lens 101 and the third lens 103. The second lens 102 can comprise plastic or glass material. For example, the second lens 102 can be made of glass. The object-side third surface S3 and the sensor-side fourth surface S4 of the second lens 102 can be formed as flat surfaces.

[0099] The second lens 102 can be a D-cut lens. The dimensions CA_L2S1 of the third surface S3 of the second lens 102 in the first direction (Y-axis direction) and CH_L2S1 in the second direction (X-axis direction) can be different. CH_L2S1 / CA_LS1 can satisfy a range of 0.1 or greater and 1 or less, and is preferably about 0.69. If it is less than the lower limit of the above conditions, it is difficult to manufacture the lens surface into a non-circular shape and it is difficult to control the distribution of incident light; and if it is greater than the upper limit of the above conditions, the effect of reducing the size of the optical system may be negligible.

[0100] The dimensions CA_L2S2 of the fourth surface S4 of the second lens 102 in the first direction (Y-axis direction) and CH_L2S2 in the second direction (X-axis direction) can be different. CH_L2S1 / CA_LS1 can satisfy a range of 0.1 or greater and 1 or less, and is preferably about 0.84. If it is less than the lower limit of the above conditions, it is difficult to manufacture the lens surface into a non-circular shape and it is difficult to control the distribution of incident light. If it exceeds the upper limit of the above conditions, the effect of reducing the size of the optical system may be negligible.

[0101] The second lens 102 can be a prism lens. The second lens 102 can be a right-angle prism lens. The second lens 102 can be a light path control component. The second lens 102 can change the path of light incident from the outside. The second lens 102 can include a reflector and a prism. The second lens 102 can rotate the light path by 90°. The second lens 102 includes an incident surface S3 for light incidence, a reflecting surface RS3 for reflecting incident light, and an exit surface S4 for emitting reflected light. The reflecting surface RS3 has a 45° tilt angle, causing the principal ray of the incident light to be reflected at 90°, thereby reflecting the incident light towards the second lens 102. The second lens 102 can reflect light incident in a first direction (Y-axis direction) and change the path of the light to a second direction (X-axis direction).

[0102] The third lens 103 can be the third one disposed from the object side. The third lens 103 can be the seventh one disposed from the sensor side. The third lens 103 can be disposed between the second lens 102 and the fourth lens 104. The third lens 103 can have positive (+) refractive power in the optical axis direction OA. The third lens 103 can include plastic or glass material. For example, the third lens 103 can be made of plastic material.

[0103] Relative to 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 also be convex. The third lens 103 can have a shape where both sides are convex in the optical axis direction OA. The third lens 103 can have aspherical surfaces. The aspherical coefficients of the fifth surface S5 and the sixth surface S6 can be provided as follows: Figure 4 L3S1 and L3S2.

[0104] The fifth surface S5 of the third lens 103 may have a critical point at the end of the effective region from the optical axis. When the fifth surface S5 has a critical point, it may be located in the range of 50% to 65%, preferably 55% to 60%, of the effective radius from the optical axis. The critical point of the fifth surface S5 may be located in the range of 1.0 mm to 2.5 mm, preferably 1.5 mm to 2.0 mm, from the optical axis. The critical point of the fifth surface S5 may be a point where the sign of the gradient value relative to the optical axis and in the direction perpendicular to the optical axis changes from positive (+) to negative (-) or from negative (-) to positive (+), and may also represent a point where the gradient value is 0. In addition, the critical point of the fifth surface S5 may be a point where the gradient value increases and then decreases, or a point where the gradient value decreases and then increases, through the tangent of the lens surface. The sixth surface S6 of the third lens 103 may be configured to have no critical point at the end of the effective region from the optical axis.

[0105] The fourth lens 104 can be disposed as the fourth lens starting from the object side. The fourth lens 104 can be disposed as the sixth lens starting from the sensor side. The fourth lens 104 can be disposed between the third lens 103 and the fifth lens 105. The fourth lens 104 can have negative (-) refractive power. The fourth lens 104 can comprise plastic or glass material. For example, the fourth lens 104 can be made of plastic material.

[0106] Relative to the optical axis, the seventh surface S7 on the object side of the fourth lens 104 is concave, and the eighth surface S8 on the sensor side can also be concave. The fourth lens 104 can have a shape where both sides are concave. The fourth lens 104 can have aspherical surfaces. The aspherical coefficients of the seventh surface S7 and the eighth surface S8 can be provided as follows: Figure 4 L4S1 and L4S2. At least one or both of the seventh surface S7 and the eighth surface S8 of the fourth lens 104 can be configured such that there is no critical point from the end of the optical axis to the effective region.

[0107] An aperture stop can be positioned between the sensor-side lens of the second lens group LG2 and the object-side lens of the third lens group LG3. An aperture stop can be positioned between the fourth lens 104 and the fifth lens 105. An aperture stop can be positioned between the sensor-side lens of the third lens group LG3 and the object-side lens of the fourth lens group LG4. By using aperture stops, the TTL within the field of view can be reduced, allowing for miniaturization of the optical system. This prevents a decrease in the weight and yield of the optical system and improves production efficiency. Furthermore, miniaturization of the optical system is possible by reducing the TTL within a diagonal field of view (FOV) of 10 to 30 degrees.

[0108] The fifth lens 105 can be configured as the fifth lens from the object side. The fifth lens 105 can also be configured as the fifth lens 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 positive (+) or negative (-) refractive power in the optical axis direction OA. The fifth lens 105 can have positive (+) refractive power. The fifth lens 105 can comprise plastic or glass material. For example, the fifth lens 105 can be made of plastic material.

[0109] Relative to the optical axis direction OA, the ninth surface S9 on the object side of the fifth lens 105 is convex, and the tenth surface S10 on the sensor side can also be convex. The fifth lens 105 can have a shape with both sides being convex. The fifth lens 105 can have aspherical surfaces. The aspherical coefficients of the ninth surface S9 and the tenth surface S10 can be provided as follows: Figure 4 L5S1 and L5S2. At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 105 may be configured such that there is no critical point from the end of the optical axis to the effective region.

[0110] The sixth lens 106 can be configured as the sixth lens from the object side. The sixth lens 106 can also be configured as the third 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 (+) or negative (-) refractive power in the optical axis direction OA. The sixth lens 106 can have negative (-) refractive power. The sixth lens 106 can comprise plastic or glass material. For example, the sixth lens 106 can be made of plastic material.

[0111] Relative to the optical axis direction OA, the eleventh surface S11 on the object side of the sixth lens 106 can be concave, and the twelfth surface S12 on the sensor side can also be concave. The sixth lens 106 can have a shape where both sides are concave. The sixth lens 106 can have aspherical surfaces. The aspherical coefficients of the eleventh surface S11 and the twelfth surface S12 can be provided as follows: Figure 4 L6S1 and L6S2. At least one or both of the eleventh surface S11 and the twelfth surface S12 of the sixth lens 106 may be configured such that there is no critical point from the end of the optical axis to the effective region.

[0112] The seventh lens 107 can be configured as the seventh from the object side. The seventh lens 107 can also be configured as the third from the sensor side. The seventh lens 107 can be positioned between the sixth lens 106 and the eighth lens 108. The seventh lens 107 can have positive (+) or negative (-) refractive power in the optical axis direction OA. The seventh lens 107 can have positive (+) refractive power. The seventh lens 107 can comprise plastic or glass material. For example, the seventh lens 107 can be made of plastic material.

[0113] Relative to the optical axis direction OA, the thirteenth surface S13 on the object side of the seventh lens 107 can be concave, and the fourteenth surface S14 on the sensor side can also be concave. The seventh lens 107 can have a concave meniscus on the object side. The seventh lens 107 can also have a convex meniscus on the sensor side. The seventh lens 107 can have aspherical surfaces. The aspherical coefficients of the thirteenth and fourteenth surfaces S14 can be provided as follows: Figure 4 L7S1 and L7S2. At least one or both of the thirteenth surface S13 and the fourteenth surface S14 of the seventh lens 107 can be configured such that there is no critical point from the end of the optical axis to the effective region.

[0114] The eighth lens 108 can be configured as the eighth lens from the object side. The eighth lens 108 can also be configured as the second lens from the sensor side. The eighth lens 108 can be positioned between the sixth lens 106 and the ninth lens 109. The eighth lens 108 can have negative (-) refractive power. The eighth lens 108 can comprise plastic or glass material. For example, the eighth lens 108 can be made of plastic material.

[0115] Relative to the optical axis direction OA, the fifteenth surface S15 on the object side of the eighth lens 108 can be convex, and the sixteenth surface S16 on the sensor side can be concave. The eighth lens 108 can have a convex meniscus facing the object side. The eighth lens 108 can have a concave meniscus facing the sensor side. The eighth lens 108 can have aspherical surfaces. The aspherical coefficients of the fifteenth surface S15 and the sixteenth surface S16 can be provided as follows: Figure 4 L8S1 and L8S2.

[0116] The fifteenth surface S15 of the eighth lens 108 may have a critical point at the end of the effective region from the optical axis. When the fifteenth surface S15 has a critical point, it may be located in the range of 1% to 10%, preferably 1% to 5%, of the effective radius from the optical axis. The critical point of the fifteenth surface S15 may be located in the range of 0 mm to 2.0 mm, preferably 0 mm to 1.0 mm, from the optical axis. The critical point of the fifteenth surface S15 may be a point where the sign of the gradient value relative to the optical axis and in the direction perpendicular to the optical axis changes from positive (+) to negative (-) or from negative (-) to positive (+), and may also represent a point where the gradient value is 0. In addition, the critical point of the fifteenth surface S15 may be a point where the gradient value increases and then decreases, or a point where the gradient value decreases and then increases, through the tangent of the lens surface. The sixteenth surface S16 of the eighth lens 108 may be configured to have no critical point at the end of the effective region from the optical axis.

[0117] The ninth lens 109 can be positioned closest to the sensor side. The ninth lens 109 can also be positioned furthest from the object side. The ninth lens 109 can have positive (+) refractive power. The ninth lens 109 can comprise plastic or glass material. For example, the ninth lens 109 can be made of plastic material.

[0118] Relative to the optical axis direction OA, the ninth lens 109 may have a seventeenth surface S17 that is concave on the object side and an eighteenth surface S18 that is convex on the sensor side. The ninth lens 109 may have a concave meniscus facing the object side. The ninth lens 109 may have a convex meniscus facing the sensor side. At least one or both of the seventeenth surface S17 and the eighteenth surface S18 may be aspherical. The aspheric coefficients of the seventeenth surface S17 and the eighteenth surface S18 may be provided as follows: Figure 4 L9S1 and L9S2.

[0119] The seventeenth surface S17 of the ninth lens 109 may have a critical point at the end of the effective region from the optical axis. When the seventeenth surface S17 has a critical point, it may be located in the range of 50% to 65%, preferably 55% to 60%, of the effective radius from the optical axis. The critical point of the seventeenth surface S17 may be located in the range of 1.5 mm to 3.0 mm, preferably 2.0 mm to 2.5 mm, from the optical axis. The critical point of the seventeenth surface S17 may be a point where the sign of the gradient value relative to the optical axis and in the direction perpendicular to the optical axis changes from positive (+) to negative (-) or from negative (-) to positive (+), and may also represent a point where the gradient value is 0. In addition, the critical point of the seventeenth surface S17 may be a point where the gradient value increases and then decreases, or a point where the gradient value decreases and then increases, through the tangent of the lens surface. The eighteenth surface S18 of the ninth lens 109 may be configured to have no critical point at the end of the effective region from the optical axis.

[0120] [Table 1]

[0121] Table 1 shows the surface number, radius of curvature, center thickness of each lens or distance between lens surfaces, refractive index (nd), Abbe number (vd), effective radius, and focal length of the lenses according to the first embodiment of the present invention. The units for radius of curvature and thickness or distance can be mm.

[0122] [Table 2]

[0123] Table 2 shows the variable lens gaps D1, D2, D3, and D4 when the optical system according to the first embodiment of the present invention operates in any of the first to third modes. Here, the first mode can represent the wide-angle end, the second mode can represent the mid-range end, and the third mode can represent the telephoto end. The wide-angle end can be referred to as wide-angle, and the telephoto end can be referred to as telephoto. In the optical system according to the first embodiment of the present invention, the distance between adjacent lens groups can change during the process of changing the magnification from the first mode to the third mode. The first and second lens groups LG1 and LG2 are fixed, and only the third to fifth lens groups LG3, LG4, and LG5 can move. The first and second lens groups LG1 and LG2 can be fixed groups, and the third to fifth lens groups LG3, LG4, and LG5 can be moving groups.

[0124] When switching from the first mode to the second mode, the distance D1 between the second lens group LG2 and the third lens group LG3 can be reduced, the distance D2 between the third lens group LG3 and the fourth lens group LG4 can be reduced, and the distance D3 between the fourth lens group LG4 and the fifth lens group LG5 can be increased.

[0125] When switching from the second mode to the third mode, the distance D1 between the second lens group LG2 and the third lens group LG3 can be decreased, the distance D2 between the third lens group LG3 and the fourth lens group LG4 can be increased, and the distance D3 between the fourth lens group LG4 and the fifth lens group LG5 can be increased.

[0126] When switching from the first mode to the third mode, the distance D1 between the second lens group LG2 and the third lens group LG3 can be reduced, the distance D2 between the third lens group LG3 and the fourth lens group LG4 can be reduced, and the distance D3 between the fourth lens group LG4 and the fifth lens group LG5 can be increased.

[0127] The travel length of the third lens group LG3 can be between 5mm and 7mm, and preferably about 6.200mm. The travel length of the fourth lens group LG4 can be between 5mm and 7mm, and preferably about 6.410mm.

[0128] The travel length of the fifth lens group LG5 can be between 0.2 mm and 0.5 mm, and preferably about 0.410 mm. The travel length of the fourth lens group LG4 can be greater than that of the third lens group LG3 and the fifth lens group LG5. The third lens group LG3, the fourth lens group LG4, and the fifth lens group LG5 can have different moving speeds. The moving speed of the fourth lens group LG4 can be greater than that of the third lens group LG3 and the fifth lens group LG5. In the first embodiment, the magnification at the wide-angle end and the telephoto end can be in the range of 1.5x to 2x, and can be about 1.99x.

[0129] [Table 3]

[0130] Table 3 shows the items of the above mathematical formula in the optical system 1000 of the first embodiment, including the effective focal length F (mm), back focal length BFL (mm), EPD (mm), SD (mm), Fno, FOV (degrees) (which is the optical axis distance from the stop to the eighteenth surface S18), and the focal lengths f1-f9 (mm) and edge thicknesses ET1-ET9 of the first to ninth lenses 101-109, the focal lengths f_LG1, f_LG2, f_LG3, f_LG4 and f_LG5 (mm) of the first to fifth lens groups LG1, LG2, LG3, LG4 and LG5, and the travel length LG3_stro of the third lens group LG3. ke, the stroke length of the fourth lens group LG4 G4_stroke, the stroke length of the fifth lens group LG5 G5_stroke, the total optical axis distance TTL (mm) and ImgH (mm) of the optical system 1000, the maximum effective diameter CA_Max, the minimum effective diameter CA_Min, the average effective diameter CA_Aver, the maximum center thickness L_CT_max, the minimum center thickness L_CT_min, the average center thickness L_CT_aver, and the length of each lens group in the optical axis direction TD_LG1, TD_LG2, TD_LG3, TD_LG4 and TD_LG5, etc.

[0131] The center thicknesses of the first to ninth lenses 101-109 are represented by CT1 to CT9, the edge thicknesses at the ends of the effective areas of each lens are represented by ET1 to ET9, the center gaps between two adjacent lenses are represented by CG1 to CG8, and the edge gaps between the edges of each lens are represented by EG1 to EG8. The back focal length BFL is the optical axis distance from the image sensor 400 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 400. Some descriptions regarding the dimensional relationships of the second lens 102, which acts as a prism lens, are omitted below.

[0132] When comparing the absolute values ​​of the radii of curvature of each lens, the radius of curvature of the fifteenth surface S15 of the eighth lens 108 in the optical axis direction OA can be the largest among the lenses, and the radius of curvature of the sixteenth surface S16 of the eighth lens 108 can be the smallest among the lenses. The absolute value of the radius of curvature of the first surface S1 of the first lens 101 can be smaller than the absolute value of the radius of curvature of the second surface S2. The absolute value of the radius of curvature of the fifth surface S5 of the third lens 103 can be smaller 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 greater 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 smaller 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 smaller 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 greater than the absolute value of the radius of curvature of the fourteenth surface S14. The absolute value of the radius of curvature of the fifteenth surface S15 of the eighth lens 108 can be greater than the absolute value of the radius of curvature of the sixteenth surface S16. The absolute value of the radius of curvature of the seventeenth surface S17 of the ninth lens 109 can be greater than the absolute value of the radius of curvature of the eighteenth surface S18.

[0133] The ratio of the radii of curvature of each lens can satisfy the following condition.

[0134] Condition 1: 0.1 < |L1R1 / L1R2| < 0.5

[0135] Condition 2: 0.5 < |L3R1 / L3R2| < 1

[0136] Condition 3: 3 < |L4R1 / L4R2| < 3.5

[0137] Condition 4: 0.5 < |L5R1 / L5R2| < 1

[0138] Condition 5: 0.1 < |L6R1 / L6R2| < 0.5

[0139] Condition 6: 2 < |L7R1 / L7R2| < 2.5

[0140] Condition 7: 500 < |L8R1 / L8R2| < 600

[0141] Condition 8: 30 < |L9R1 / L9R2| < 40

[0142] When interpreting the center thickness of a lens relative to the optical axis, the center thicknesses CT5 and CT7 of the fifth lens 105 and the seventh lens 107 are the largest, while the center thickness CT4 of the fourth lens 104 is the smallest. The difference between the maximum and minimum center thickness of a lens can be in the range of 2 mm or more and 3 mm or less.

[0143] The center thickness of each lens can satisfy any of the following conditions.

[0144] Condition 1: CT5, CT7 > CT1 > CT3, CT4, CT6, CT8, CT9

[0145] Condition 2: CT1, CT5, CT6, CT7, CT8, CT9 > CT3 > CT4

[0146] Condition 3: CT1, CT3, CT5, CT6, CT7, CT8, CT9 > CT4

[0147] Condition 4: CT5 = CT7 > CT1, CT3, CT4, CT6, CT8, CT9

[0148] Condition 5: CT1, CT5, CT7, CT9 > CT6 > CT3, CT4, CT8

[0149] Condition 6: CT1, CT5, CT6, CT7, CT9 > CT8 > CT3, CT4

[0150] Condition 7: CT1, CT5, CT7 > CT9 > CT3, CT4, CT6, CT8

[0151] During zooming, the gaps CG1 between the first lens 101 and the second lens 102, CG2 between the second lens 102 and the third lens 103, CG3 between the third lens 103 and the fourth lens 104, CG5 between the fifth lens 105 and the sixth lens 106, and CG7 between the seventh lens 107 and the eighth lens 108 remain constant, while the gaps CG4 between the fourth lens 104 and the fifth lens 105, CG6 between the sixth lens 106 and the seventh lens 107, and CG8 between the eighth lens 108 and the ninth lens 109 can vary. Among the constant center gaps between the lenses, the center gap CG2 between the second lens 102 and the third lens 103 can be the largest, and the center gap CG5 between the fifth lens 105 and the sixth lens 106 can be the smallest. The difference between the largest and smallest center gaps among the spaced lens gaps can be 1 mm or greater, for example, in the range of 1 mm to 1.3 mm.

[0152] The center gap between each lens can meet the following conditions.

[0153] Condition 1: CG2 > CG1 > CG3, CG5, CG7

[0154] Condition 2: CG2 > CG1, CG3, CG5, CG7

[0155] Condition 3: CG1, CG2 > CG3 > CG5, CG7

[0156] Condition 4: CG1, CG2, CG3, CG7 > CG5

[0157] Condition 5: CG1, CG2, CG3 > CG7 > CG5

[0158] Regarding the effective diameter, the lens with the largest effective diameter can be the first lens 101. Here, the effective diameter is the average of the effective diameters of the object-side surface and the sensor-side surface of each lens. The lens surface with the largest effective diameter can be the first surface S1 of the first lens 101. The lens with the smallest effective diameter can be the seventh lens 107. The lens surface with the smallest effective diameter can be the twelfth surface S12 of the sixth lens 106.

[0159] The effective diameter of each lens can satisfy any of the following conditions.

[0160] Condition 1: CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7, CA_L8, CA_L9

[0161] Condition 2: CA_L1, CA_L9 > CA_L2 > CA_L3, CA_L4, CA_L5, CA_L6, CA_L7, CA_L8

[0162] Condition 3: CA_L1, CA_L2, CA_L9 > CA_L3 > CA_L4, CA_L5, CA_L6, CA_L7, CA_L8

[0163] Condition 4: CA_L1, CA_L2, CA_L3, CA_L9 > CA_L4 > CA_L5, CA_L6, CA_L7, CA_L8

[0164] Condition 5: CA_L1, CA_L2, CA_L3, CA_L4, CA_L9 > CA_L5 > CA_L6, CA_L7, CA_L8

[0165] Condition 6: CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L9 > CA_L6 > CA_L7, CA_L8

[0166] Condition 7: CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L8, CA_L9 > CA_L7

[0167] Condition 8: CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L9 > CA_L8 > CA_L7

[0168] Condition 9: CA_L1 > CA_L9 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7, CA_L8

[0169] When interpreting refractive index, the second lens 102 has the highest refractive index among the lenses and can be greater than 1.6, for example, greater than 1.7. The third lens 103 and the fifth lens 105 have the lowest refractive indices among the lenses and can be less than 1.6, for example, less than 1.55. The difference between the maximum and minimum refractive indices can be 0.15 or greater.

[0170] The refractive index of each lens can satisfy any of the following conditions.

[0171] Condition 1: n2, n7, n9 > n1 > n3, n4, n5, n6, n8

[0172] Condition 2: n2 > n1, n3, n4, n5, n6, n7, n8, n9

[0173] Condition 3: n1, n2, n4, n6, n7, n8, n9 > n3 = n5

[0174] Condition 4: n1, n2, n6, n7, n9 > n4 = n8 > n3, n5

[0175] Condition 5: n1, n2, n7, n9 > n6 > n3, n4, n5, n8

[0176] Condition 6: n2 > n7 = n9 > n1, n3, n4, n5, n6, n8

[0177] When comparing Abbe numbers, the fifth lens 105 has the highest Abbe number among the lenses, and can be 50 or greater. The seventh lens 107 and the ninth lens 109 have the lowest Abbe numbers 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.

[0178] The Abbe number of each lens can satisfy any of the following conditions.

[0179] Condition 1: v2, v3, v4, v5, v6, v8 > v1 > v7, v9

[0180] Condition 2: v3, v4, v5, v8 > v2 > v1, v6, v7, v9

[0181] Condition 3: v5 > v3 > v1, v2, v4, v6, v7, v8, v9

[0182] Condition 4: v3, v5 > v4 > v1, v2, v6, v7, v8, v9

[0183] Condition 5: v5 > v1, v2, v3, v4, v6, v7, v8, v9

[0184] Condition 6: v2, v3, v4, v5, v8 > v6 > v1, v7, v9

[0185] Condition 7: v1, v2, v3, v4, v5, v6, v8 > v7 = v9

[0186] Condition 8: v3, v4, v5 > v8 > v1, v2, v6, v7, v9

[0187] The focal lengths F1, F3, F5, F7, and F9 of the first, third, fifth, seventh, and ninth lenses (101, 103, 105, 107, and 109) can have a positive (+) refractive power. The focal lengths F4, F6, and F8 of the fourth, sixth, and eighth lenses (104, 106, and 108) can have a negative (-) refractive power.

[0188] When comparing focal lengths in absolute terms, the first lens 101 has the largest focal length among the lenses, and it can be 30 or greater and 50 or less. The eighth lens 108 has the smallest focal length among the lenses, and the absolute value of the focal length of the eighth lens 108 can be 5 or greater and 8 or less.

[0189] The absolute value of the focal length of each lens can satisfy any of the following conditions.

[0190] Condition 1: |f1| > |f3|, |f4|, |f5|, |f6|, |f7|, |f8|, |f9|

[0191] Condition 2: |f1| > |f3| > |f4|, |f5|, |f6|, |f7|, |f8|, |f9|

[0192] Condition 3: |f1|, |f3|, |f6|, |f7|, |f9| > |f4| > |f5|, |f8|

[0193] Condition 4: |f1|, |f3|, |f4|, |f6|, |f7|, |f9| > |f5| > |f8|

[0194] Condition 5: |f1|, |f3| > |f6| > |f4|, |f5|, |f7|, |f8|, |f9|

[0195] Condition 6: |f1|, |f3|, |f6| > |f7| > |f4|, |f5|, |f8|, |f9|

[0196] Condition 7: |f1|, |f3|, |f4|, |f5|, |f6|, |f7|, |f9| > |f8|

[0197] Condition 8: |f1|, |f3|, |f6|, |f7| > |f9| > |f4|, |f5|, |f8|

[0198] The combined focal length f_LG1 of the first lens group LG1 can have a positive (+) sign. The first lens group LG1 can have a positive (+) combined refractive power. The combined focal length f_LG2 of the second lens group LG2 can have a negative (-) sign. The second lens group LG2 can have a negative (-) combined refractive power. The combined focal length f_LG3 of the third lens group LG3 can have a positive (+) sign. The third lens group LG3 can have a positive (+) combined refractive power. The combined focal length f_LG4 of the fourth lens group G4 can have a negative (-) sign. The fourth lens group G4 can have a negative (-) combined refractive power. In this way, light incident on the object side can move away from the optical axis and then converge back towards the optical axis, thus forming a stable optical path. The combined focal length f_LG5 of the fifth lens group LG5 can have a positive (+) sign. The fifth lens group LG5 can have a positive (+) combined refractive power.

[0199] When comparing the combined focal lengths of the first to fifth lens groups LG1, LG2, LG3, LG4, and LG5 in absolute values, the combined focal length of the first lens group LG1 can be the largest, and the combined focal length of the third lens group LG3 can be the smallest. The combined focal length relationship of the first to fifth lens groups LG1, LG2, LG3, LG4, and LG5 can satisfy |f_LG1| > |f_LG5| > |f_LG2| > |f_LG4| > |f_LG3|.

[0200] The thickness T1 of the first lens 101 is minimum at the edge and maximum at the center, with the maximum thickness ranging from 1 to 1.5 times the minimum thickness. The thickness T3 of the third lens 103 can be maximum at the center and minimum at the edge, with the maximum thickness ranging from 1.5 to 2 times the minimum thickness. The thickness T4 of the fourth lens 104 can be minimum at the center and maximum at the edge, with the maximum thickness ranging from 2 to 2.5 times the minimum thickness. The thickness T5 of the fifth lens 105 can be maximum at the center and minimum at the edge, with the maximum thickness ranging from 2 to 2.5 times the minimum thickness. The thickness T6 of the sixth lens 106 can be minimum at the center and maximum at the edge, with the maximum thickness ranging from 1 to 1.5 times the minimum thickness. The thickness T7 of the seventh lens 107 can be maximum at the center and minimum at the edge, with the maximum thickness ranging from 1 to 1.5 times the minimum thickness. The thickness T8 of the eighth lens 108 can be minimum at the center and maximum at the edge, with the maximum thickness ranging from 1.5 to 2.5 times the minimum thickness. The thickness T9 of the ninth lens 109 can be maximum at the center and minimum at the edge, with the maximum thickness ranging from 1.5 to 2 times the minimum thickness.

[0201] The thickness of each lens can satisfy any of the following conditions.

[0202] Condition 1: 1 < CT1 / ET1 < 1.5, 0.5 < ET1 / CT1 < 1

[0203] Condition 2: 1.5 < CT3 / ET3 < 2, 0.5 < ET3 / CT3 < 1

[0204] Condition 3: 0.1 < CT4 / ET4 < 0.5, 2 < ET4 / CT4 < 2.5

[0205] Condition 4: 2 < CT5 / ET5 < 2.5, 0.1 < ET5 / CT5 < 0.5

[0206] Condition 5: 0.5 < CT6 / ET6 < 1, 1 < ET6 / CT6 < 1.5

[0207] Condition 6: 1 < CT7 / ET7 < 1.5, 0.5 < ET7 / CT7 < 1

[0208] Condition 7: 0.1 < CT8 / ET8 < 1, 1.5 < ET8 / CT8 < 2.5

[0209] Condition 8: 1.5 < CT9 / ET9 < 2, 0.5 < ET9 / CT9 < 1

[0210] Condition 9: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0211] Among the gaps G1-G8 between the lenses, the gap G1 between the first and second lenses 101 and 102 can have a maximum value at the center and a minimum value at the edge. The gap G2 between the second and third lenses 102 and 103 can have a minimum value at the edge and a maximum value at the center. The gap G3 between the third and fourth lenses 103 and 104 can have a minimum value at the edge and a maximum value at the center. The gap G4 between the fourth and fifth lenses 104 and 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 and 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 and 107 can have a maximum value at the center and a minimum value at the edge. The seventh gap G7 between the seventh and eighth lenses 107 and 108 can have a maximum value at the center and a minimum value at the edge. The eighth gap G8 between the eighth and ninth lenses 108 and 109 can have a maximum value at the center and a minimum value at the edge.

[0212] Figure 5 , Figure 6 and Figure 7 It is a graph showing the aberration characteristics at the wide-angle end, middle end and telephoto end of the optical system according to the first embodiment of the present invention. Figure 5 , Figure 6 and Figure 7 The aberration curves are graphs measuring spherical aberration (longitudinal spherical aberration), astigmatism, and distortion from left to right. Figure 5 , Figure 6 and Figure 7 In the graph, the X-axis represents focal length (mm) and distortion (%), while the Y-axis represents image height. Additionally, the spherical aberration graph is for light in the wavelength bands of approximately 435 nm, 486 nm, 546 nm, 587 nm, and 656 nm, and the astigmatism and distortion graphs are for light in the wavelength band of approximately 546 nm. Figure 5 , Figure 6 and Figure 7 In the aberration diagram, the closer each curve is to the Y-axis at the wide-angle, mid-range, and telephoto ends, the better it illustrates the aberration correction function. It can be seen that the optical system 1000 according to the first embodiment has measurements close to the Y-axis in almost all regions. That is, the optical system 1000 according to the first embodiment has enhanced resolution and good optical performance not only at the center of the field of view (FOV) but also at its periphery.

[0213] An optical system according to a second embodiment of the present invention will be described.

[0214] Figure 8 This is a configuration diagram of an optical system according to a second embodiment of the present invention operating in the first mode; Figure 9 This is a configuration diagram of an optical system according to a second embodiment of the present invention operating in the second mode; Figure 10 This is a configuration diagram of an optical system according to a second embodiment of the present invention operating in the third mode; Figure 11 This is a table showing the aspherical coefficients of the lenses in the optical system according to the second embodiment; Figure 12 It is a graph showing the aberration characteristics of the optical system according to the second embodiment operating in the first mode; Figure 13 It is a graph showing data regarding the aberration characteristics of the optical system according to the second embodiment operating in the second mode; and Figure 14 It is a graph showing the aberration characteristics of the optical system according to the second embodiment operating in the third mode.

[0215] refer to Figures 8 to 10The optical system 1100 includes a lens unit, which may include a first lens 201 to a ninth lens 209. The first to ninth lenses 201-209 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 to ninth lenses 201-209 and the filter 500 and be incident on the image sensor 400.

[0216] The first lens 201 can be positioned closest to the object side. The first lens 201 can also be positioned furthest from the sensor side. The first lens 201 can have positive (+) refractive power in the optical axis direction OA. The first lens 201 can comprise plastic or glass material, and can be, for example, plastic material.

[0217] Relative to the optical axis direction OA, the first surface S1 on the object side of the first lens 201 is convex, and the second surface S2 on the sensor side can be concave. The first lens 201 can have a meniscus shape in which the object side is convex. The first lens 201 can have a meniscus shape in which the sensor side is concave. The first lens 201 can have an aspherical surface. The aspherical coefficients of the first and second surfaces S1 and S2 can be provided as follows: Figure 11 L1S1 and L1S2. The first lens 101 may be a D-cut lens. At least one or both of the first surface S1 and the second surface S2 of the first lens 101 may be configured such that there is no critical point from the optical axis to the end of the effective region.

[0218] The second lens 202 can be disposed as a second lens starting from the object side. The second lens 202 can be disposed as an eighth lens starting from the sensor side. The second lens 202 can be disposed between the first lens 201 and the third lens 203. The second lens 202 can comprise plastic or glass material. For example, the second lens 202 can be made of glass material. The third surface S3 on the object side and the fourth surface S4 on the sensor side of the second lens 202 can be formed as flat surfaces.

[0219] The second lens 202 can be a D-cut lens. The dimensions CA_L2S1 of the third surface S3 of the second lens 202 in the first direction (Y-axis direction) and CH_L2S1 in the second direction (X-axis direction) can be different. CH_L2S1 / CA_LS1 can satisfy a range of 0.1 or greater and 1 or less, and is preferably about 0.74. If it is less than the lower limit of the above conditions, it is difficult to manufacture the lens surface into a non-circular shape and it is difficult to control the distribution of incident light; and if it is greater than the upper limit of the above conditions, the effect of reducing the size of the optical system may be negligible.

[0220] The dimensions CA_L2S2 of the fourth surface S4 of the second lens 202 in the first direction (Y-axis direction) and CH_L2S2 in the second direction (X-axis direction) can be different. CH_L2S1 / CA_LS1 can satisfy a range of 0.1 or greater and 1 or less, and is preferably about 0.89. If it is less than the lower limit of the above conditions, it is difficult to manufacture the lens surface into a non-circular shape and it is difficult to control the distribution of incident light. If it exceeds the upper limit of the above conditions, the effect of reducing the size of the optical system may be negligible.

[0221] The second lens 202 can be a prism lens. The second lens 202 can be a right-angle prism lens. The second lens 202 can be a light path control component. The second lens 202 can change the path of light incident from the outside. The second lens 202 can include a reflector and a prism. The second lens 202 can rotate the light path by 90°. The second lens 202 includes an incident surface S3 for light incidence, a reflecting surface RS3 for reflecting incident light, and an exit surface S4 for emitting reflected light. The reflecting surface RS3 has a 45° tilt angle and reflects the principal ray of the incident light at a 90° angle, thereby reflecting the incident light towards the second lens 202. The second lens 202 can reflect light incident in a first direction (Y-axis direction) and change the path of the light to a second direction (X-axis direction).

[0222] The third lens 203 can be the third one disposed from the object side. The third lens 203 can be the seventh one disposed from the sensor side. The third lens 203 can be disposed between the second lens 202 and the fourth lens 204. The third lens 203 can have negative (-) refractive power in the optical axis direction OA. The third lens 203 can include plastic or glass material. For example, the third lens 203 can be made of plastic material.

[0223] Relative to the optical axis, the object-side fifth surface S5 of the third lens 203 can be convex, and the sensor-side sixth surface S6 can be concave. The third lens 203 can have a meniscus shape that is convex on the object side along the optical axis OA. The third lens 203 can also have a meniscus shape that is concave on the sensor side along the optical axis OA. The third lens 103 can have aspherical surfaces. The aspherical coefficients of the fifth surface S5 and the sixth surface S6 can be provided as follows: Figure 11 L3S1 and L3S2. At least one or both of the fifth surface S5 and the sixth surface S6 of the third lens 103 may be configured such that there is no critical point from the end of the optical axis to the effective region.

[0224] The fourth lens 204 can be disposed as the fourth lens starting from the object side. The fourth lens 204 can be disposed as the sixth lens starting from the sensor side. The fourth lens 204 can be disposed between the third lens 203 and the fifth lens 205. The fourth lens 204 can have negative (-) refractive power. The fourth lens 204 can comprise plastic or glass material. For example, the fourth lens 204 can be made of plastic material.

[0225] Relative to the optical axis, the seventh surface S7 on the object side of the fourth lens 204 is concave, and the eighth surface S8 on the sensor side can also be concave. The fourth lens 204 can have a meniscus shape in which the object side is convex. The fourth lens 204 can have a meniscus shape in which the sensor side is concave. The fourth lens 204 can have aspherical surfaces. The aspherical coefficients of the seventh surface S7 and the eighth surface S8 can be provided as follows: Figure 11 L4S1 and L4S2.

[0226] The seventh surface S7 of the fourth lens 104 may have a critical point at the end of the effective region from the optical axis. When the seventh surface S7 has a critical point, it may be located in the range of 1% to 20%, preferably 5% to 15%, of the effective radius from the optical axis. The critical point of the seventh surface S7 may be located in the range of 0.1 mm to 1.0 mm, preferably 0.1 mm to 0.5 mm, from the optical axis. The critical point of the seventh surface S7 may be a point where the sign of the gradient value relative to the optical axis and in the direction perpendicular to the optical axis changes from positive (+) to negative (-) or from negative (-) to positive (+), and may also represent a point where the gradient value is 0. In addition, the critical point of the seventh surface S7 may be a point where the gradient value increases and then decreases, or a point where the gradient value decreases and then increases, through the tangent of the lens surface. The eighth surface S8 of the fourth lens 104 may be configured to have no critical point at the end of the effective region from the optical axis.

[0227] An aperture stop can be positioned between the sensor-side lens of the second lens group LG2 and the object-side lens of the third lens group LG3. An aperture stop can be positioned between the fourth lens 204 and the fifth lens 205. An aperture stop can be positioned between the sensor-side lens of the third lens group LG3 and the object-side lens of the fourth lens group LG4. By using aperture stops, the TTL within the field of view can be reduced, allowing for miniaturization of the optical system. This prevents a decrease in the weight and yield of the optical system and improves production efficiency. Furthermore, miniaturization of the optical system can be achieved by reducing the TTL within a diagonal field of view (FOV) of 10 to 30 degrees.

[0228] 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 fifth 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 positive (+) or negative (-) refractive power in the optical axis direction OA. The fifth lens 205 can have positive (+) refractive power. The fifth lens 205 can comprise plastic or glass material. For example, the fifth lens 205 can be made of plastic material.

[0229] Relative to the optical axis direction OA, the ninth surface S9 on the object side of the fifth lens 205 is convex, and the tenth surface S10 on the sensor side can also be convex. The fifth lens 205 can have a shape where both sides are convex. The fifth lens 205 can have aspherical surfaces. The aspherical coefficients of the ninth surface S9 and the tenth surface S10 can be provided as follows: Figure 11 L5S1 and L5S2. At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 205 can be configured such that there is no critical point from the end of the optical axis to the effective region.

[0230] The sixth lens 206 can be configured as the sixth lens from the object side. The sixth lens 206 can also be configured as the third 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 (+) or negative (-) refractive power in the optical axis direction OA. The sixth lens 206 can have negative (-) refractive power. The sixth lens 206 can comprise plastic or glass material. For example, the sixth lens 206 can be made of plastic material.

[0231] Relative to the optical axis direction OA, the sixth lens 206 may have an eleventh surface S11 on the object side and a twelfth surface S12 on the sensor side. The sixth lens 206 may have a shape with convex surfaces on both sides. The sixth lens 206 may have aspherical surfaces. The aspherical coefficients of the eleventh surface S11 and the twelfth surface S12 can be provided as follows: Figure 11 L6S1 and L6S2. At least one or both of the eleventh surface S11 and the twelfth surface S12 of the sixth lens 206 can be configured such that there is no critical point from the end of the optical axis to the effective region.

[0232] The seventh lens 207 can be configured as the seventh from the object side. The seventh lens 207 can also be configured as the third from the sensor side. The seventh lens 207 can be positioned between the sixth lens 206 and the eighth lens 208. The seventh lens 207 can have positive (+) or negative (-) refractive power in the optical axis direction OA. The seventh lens 207 can have positive (+) refractive power. The seventh lens 207 can comprise plastic or glass material. For example, the seventh lens 207 can be made of plastic material.

[0233] Relative to the optical axis direction OA, the thirteenth surface S13 on the object side of the seventh lens 207 is concave, and the fourteenth surface S14 on the sensor side can be convex. The seventh lens 207 can have a concave meniscus on the object side. The seventh lens 207 can have a convex meniscus on the sensor side. The seventh lens 207 can have aspherical surfaces. The aspherical coefficients of the thirteenth surface S13 and the fourteenth surface S14 can be provided as follows: Figure 11 L7S1 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 such that there is no critical point from the end of the optical axis to the effective region.

[0234] The eighth lens 208 can be configured as the eighth lens from the object side. The eighth lens 208 can also be configured as the second lens from the sensor side. The eighth lens 208 can be positioned between the sixth lens 206 and the ninth lens 209. The eighth lens 208 can have negative (-) refractive power. The eighth lens 208 can comprise plastic or glass material. For example, the eighth lens 208 can be made of plastic material.

[0235] Relative to the optical axis direction OA, the fifteenth surface S15 on the object side of the eighth lens 208 can be concave, and the sixteenth surface S16 on the sensor side can be concave. The eighth lens 208 can have a convex meniscus facing the object side. The eighth lens 208 can have a concave meniscus facing the sensor side. The eighth lens 208 can have aspherical surfaces. The aspherical coefficients of the fifteenth surface S15 and the sixteenth surface S16 can be provided as follows: Figure 11 L8S1 and L8S2.

[0236] The ninth lens 209 can be positioned closest to the sensor side. The ninth lens 209 can also be positioned furthest from the object side. The ninth lens 209 can have positive (+) refractive power. The ninth lens 209 can comprise plastic or glass material. For example, the ninth lens 209 can be made of plastic material.

[0237] Relative to the optical axis direction OA, the ninth lens 209 may have a seventeenth surface S17 that is concave on the object side and an eighteenth surface S18 that is convex on the sensor side. The ninth lens 209 may have a concave meniscus facing the object side. The ninth lens 209 may have a convex meniscus facing the sensor side. At least one or both of the seventeenth surface S17 and the eighteenth surface S18 may be aspherical. The aspherical coefficients of the seventeenth surface S17 and the eighteenth surface S18 may be provided as follows: Figure 11 L9S1 and L9S2.

[0238] The seventeenth surface S17 of the ninth lens 209 may have a critical point at the end of the effective region from the optical axis. When the seventeenth surface S17 has a critical point, it may be located in the range of 5% to 20%, preferably 10% to 15%, of the effective radius from the optical axis. The critical point of the seventeenth surface S17 may be located in the range of 0.1 mm to 1.0 mm, preferably 0.1 mm to 0.5 mm, from the optical axis. The critical point of the seventeenth surface S17 may be a point where the sign of the gradient value relative to the optical axis and in the direction perpendicular to the optical axis changes from positive (+) to negative (-) or from negative (-) to positive (+), and may also represent a point where the gradient value is 0. Furthermore, the critical point of the seventeenth surface S17 may be a point where the gradient value increases and then decreases, or a point where the gradient value decreases and then increases, through the tangent of the lens surface. The eighteenth surface S18 of the ninth lens 209 may be configured to have no critical point at the end of the effective region from the optical axis.

[0239] [Table 4]

[0240] Table 4 shows the surface number, radius of curvature, center thickness of each lens or distance between lens surfaces, refractive index (nd), Abbe number (vd), effective radius, and focal length of the lenses according to the second embodiment of the present invention. Here, the units for radius of curvature and thickness or distance can be mm.

[0241] [Table 5]

[0242] Table 5 shows the variable lens gaps D1, D2, and D3 when the optical system according to the second embodiment of the present invention operates in any of the first to third modes. Here, the first mode can represent the wide-angle end, the second mode can represent the mid-range end, and the third mode can represent the telephoto end. The wide-angle end can be referred to as wide-angle, and the telephoto end can be referred to as telephoto. In the optical system according to the second embodiment of the present invention, the distance between adjacent lens groups can change during the process of changing the magnification from the first mode to the third mode. The first, second, and fifth lens groups LG1, LG2, and LG5 are fixed, and only the third and fourth lens groups LG3 and LG4 can be movable. The first, second, and fifth lens groups LG1, LG2, and LG5 can be fixed groups, and the third and fourth lens groups LG3 and LG4 can be movable groups.

[0243] When switching from the first mode to the second mode, the distance D1 between the second lens group LG2 and the third lens group LG3 can be reduced, the distance D2 between the third lens group LG3 and the fourth lens group LG4 can be reduced, and the distance D3 between the fourth lens group LG4 and the fifth lens group LG5 can be increased.

[0244] When switching from the second mode to the third mode, the distance D1 between the second lens group LG2 and the third lens group LG3 can be decreased, the distance D2 between the third lens group LG3 and the fourth lens group LG4 can be increased, and the distance D3 between the fourth lens group LG4 and the fifth lens group LG5 can be increased.

[0245] When switching from the first mode to the third mode, the distance D1 between the second lens group LG2 and the third lens group LG3 can be decreased, the distance D2 between the third lens group LG3 and the fourth lens group LG4 can be increased, and the distance D3 between the fourth lens group LG4 and the fifth lens group LG5 can be increased.

[0246] The travel length of the third lens group LG3 can be between 5mm and 7mm, and preferably about 5.540mm. The travel length of the fourth lens group LG4 can be between 5mm and 7mm, and preferably about 5.220mm. The travel length of the third lens group LG3 can be greater than that of the fourth lens group LG4. The third lens group LG3 and the fourth lens group LG4 can have different moving speeds. The moving speed of the third lens group LG3 can be greater than that of the fourth lens group LG4. In the second embodiment, the magnification at the wide-angle end and the telephoto end can be in the range of 1.5x to 2x, and can be about 1.99x.

[0247] [Table 6]

[0248] Table 6 shows the items of the above mathematical formula in the optical system 1100 of the second embodiment, including effective focal length F (mm), back focal length BFL (mm), EPD (mm), SD (mm), Fno, HFOV (degrees) (which is the optical axis distance from the stop to the eighteenth surface S18), and the focal lengths f1-f9 (mm) and edge thicknesses ET1-ET9 of the first to ninth lenses 201-209, the focal lengths f_LG1, f_LG2, f_LG3, f_LG4 and f_LG5 (mm) of the first to fifth lens groups LG1, LG2, LG3, LG4 and LG5, and the row of the third lens group LG3. The stroke length LG3_stroke, the stroke length G4_stroke of the fourth lens group LG4, the total optical axis distance TTL (mm) and ImgH (mm) of the optical system 1100, the maximum effective diameter CA_Max, the minimum effective diameter CA_Min, the average effective diameter CA_Aver, the maximum center thickness L_CT_max, the minimum center thickness L_CT_min, the average center thickness L_CT_aver of the first to ninth lenses 201-209, and the lengths TD_LG1, TD_LG2, TD_LG3, TD_LG4 and TD_LG5 of each lens group in the optical axis direction, etc.

[0249] The center thicknesses of the first to ninth lenses 201-209 are represented by CT1 to CT9, the edge thicknesses at the ends of the effective areas of each lens are represented by ET1 to ET9, the center gaps between two adjacent lenses are represented by CG1 to CG8, and the edge gaps between the edges of each lens are represented by EG1 to EG8. The back focal length (BFL) is the optical axis distance from the image sensor 400 to the center of the last lens. The TTL is the optical axis distance from the center of the first surface S1 of the first lens 201 to the upper surface of the image sensor 400. In the following description, some descriptions regarding the dimensional relationships of the second lens 102, which serves as a prism lens, are omitted.

[0250] When comparing the absolute values ​​of the radii of curvature of each lens, the radius of curvature of the seventh surface S7 of the fourth lens 204 along the optical axis OA can be the largest among the lenses, and the radius of curvature of the sixteenth surface S16 of the eighth lens 208 can be 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 smaller than the absolute value of the radius of curvature of the second surface S2. 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 greater 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 smaller 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 smaller 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 greater than the absolute value of the radius of curvature of the fourteenth surface S14. The absolute value of the radius of curvature of the fifteenth surface S15 of the eighth lens 208 can be greater than the absolute value of the radius of curvature of the sixteenth surface S16. The absolute value of the radius of curvature of the seventeenth surface S17 of the ninth lens 209 can be greater than the absolute value of the radius of curvature of the eighteenth surface S18.

[0251] The ratio of the radii of curvature of each lens can satisfy the following condition.

[0252] Condition 1: 0.1 < |L1R1 / L1R2| < 0.5

[0253] Condition 2: 1.5 < |L3R1 / L3R2| < 2

[0254] Condition 3: 80 < |L4R1 / L4R2| < 90

[0255] Condition 4: 0.5 < |L5R1 / L5R2| < 1

[0256] Condition 5: 0.1 < |L6R1 / L6R2| < 0.5

[0257] Condition 6: 1.5 < |L7R1 / L7R2| < 2

[0258] Condition 7: 10 < |L8R1 / L8R2| < 20

[0259] Condition 8: 60 < |L9R1 / L9R2| < 70

[0260] When interpreting the center thickness of a lens relative to the optical axis, the center thickness CT7 of the seventh lens 207 is the largest among the lenses, while the center thicknesses CT3 and CT4 of the third lens 203 and the fourth lens 204 are the smallest. The difference between the maximum and minimum center thickness of a lens can be in the range of 2 mm or greater and 3 mm or less.

[0261] The center thickness of each lens can satisfy any of the following conditions.

[0262] Condition 1: CT5, CT6, CT7, CT9 > CT1 > CT3, CT4, CT8

[0263] Condition 2: CT1, CT5, CT6, CT7, CT8, CT9 > CT3 = CT4

[0264] Condition 3: CT7 > CT5 > CT1, CT3, CT4, CT6, CT8, CT9

[0265] Condition 4: CT5, CT7 > CT6 > CT1, CT3, CT4, CT8, CT9

[0266] Condition 5: CT7 > CT1, CT3, CT4, CT5, CT6, CT8, CT9

[0267] Condition 6: CT1, CT5, CT6, CT7, CT9 > CT8 > CT3, CT4

[0268] Condition 7: CT5, CT6, CT7 > CT9 > CT1, CT3, CT4, CT8

[0269] During zooming, the gaps CG1 between the first lens 201 and the second lens 202, CG2 between the second lens 202 and the third lens 203, CG3 between the third lens 203 and the fourth lens 204, CG5 between the fifth lens 205 and the sixth lens 206, and CG7 between the seventh lens 207 and the eighth lens 208 remain constant, while the gaps CG4 between the fourth lens 204 and the fifth lens 205, CG6 between the sixth lens 206 and the seventh lens 207, and CG8 between the eighth lens 208 and the ninth lens 209 can vary. Among the constant center gaps between the lenses, the center gap CG2 between the second lens 202 and the third lens 203 can be the largest, and the center gap CG5 between the fifth lens 205 and the sixth lens 206 can be the smallest. The difference between the largest and smallest center gaps among the spaced lens gaps can be 0.7 mm or greater, for example, in the range of 0.9 mm to 1 mm.

[0270] The center gap between each lens can meet the following conditions.

[0271] Condition 1: CG2 > CG1 > CG3, CG5, CG7

[0272] Condition 2: CG2 > CG1, CG3, CG5, CG7

[0273] Condition 3: CG1, CG2 > CG3 > CG5, CG7

[0274] Condition 4: CG1, CG2, CG3, CG7 > CG5

[0275] Condition 5: CG1, CG2, CG3 > CG7 > CG5

[0276] Regarding the effective diameter, the lens with the largest effective diameter can be the first lens 201. Here, the effective diameter is the average of the effective diameters of the object-side surface and the sensor-side surface of each lens. The lens surface with the largest effective diameter can be the first surface S1 of the first lens 201. The lens with the smallest effective diameter can be the seventh lens 207. The lens surface with the smallest effective diameter can be the twelfth surface S12 of the sixth lens 206.

[0277] The effective diameter of each lens can satisfy any one of the following conditions.

[0278] Condition 1: CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7, CA_L8, CA_L9

[0279] Condition 2: CA_L1, CA_L9 > CA_L2 > CA_L3, CA_L4, CA_L5, CA_L6, CA_L7, CA_L8

[0280] Condition 3: CA_L1, CA_L2, CA_L9 > CA_L3 > CA_L4, CA_L5, CA_L6, CA_L7, CA_L8

[0281] Condition 4: CA_L1, CA_L2, CA_L3, CA_L5, CA_L9 > CA_L4 > CA_L6, CA_L7, CA_L8

[0282] Condition 5: CA_L1, CA_L2, CA_L3, CA_L9 > CA_L5 > CA_L4, CA_L6, CA_L7, CA_L8

[0283] Condition 6: CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L8, CA_L9 > CA_L6 > CA_L7

[0284] Condition 7: CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L8, CA_L9 > CA_L7

[0285] Condition 8: CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L9 > CA_L8 > CA_L6, CA_L7

[0286] Condition 9: CA_L1 > CA_L9 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7, CA_L8

[0287] In terms of refractive index, the second lens 202 has the highest refractive index among the lenses, and can be greater than 1.6, for example, greater than 1.7. The third lens 203, the fifth lens 205, and the eighth lens 208 have the lowest refractive indices among the lenses, and can be less than 1.6, for example, less than 1.55. The difference between the maximum and minimum refractive indices can be 0.15 or greater.

[0288] The refractive index of each lens can satisfy any of the following conditions.

[0289] Condition 1: n2 > n1 = n7 = n9 > n3, n4, n5, n6, n8

[0290] Condition 2: n2 > n1, n3, n4, n5, n6, n7, n8, n9

[0291] Condition 3: n1, n2, n4, n6, n7, n9 > n3 = n5 = n8

[0292] Condition 4: n1, n2, n7, n9 > n4 > n3, n5, n6, n8

[0293] Condition 5: n1, n2, n4, n7, n9 > n6 > n3, n5, n8

[0294] When comparing Abbe numbers, the Abbe numbers of the third lens 203, the fifth lens 205, and the eighth lens 208 are the largest among the lenses, and can be 50 or greater. The Abbe numbers of the first lens 201, the seventh lens 207, and the ninth lens 209 are 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.

[0295] The Abbe number of each lens can satisfy any of the following conditions.

[0296] Condition 1: v2, v3, v4, v5, v6, v8 > v1 = v7 = v9

[0297] Condition 2: v3, v5, v8 > v2 > v1, v4, v6, v7, v9

[0298] Condition 3: v3 = v5 = v8 > v1, v2, v4, v6, v7, v9

[0299] Condition 4: v2, v3, v5, v6, v8 > v4 > v1, v7, v9

[0300] Condition 5: v2, v3, v5, v8 > v6 > v1, v4, v7, v9

[0301] The focal lengths F1, F5, F7, and F9 of the first, fifth, seventh, and ninth lenses 201, 205, 207, and 209 can have a positive (+) refractive power. The focal lengths F3, F4, F6, and F8 of the third, fourth, sixth, and eighth lenses 203, 204, 206, and 208 can have a negative (-) refractive power.

[0302] When comparing focal lengths in absolute terms, the first lens 201 has the largest focal length among the lenses, and it can be 30 or greater and 50 or less. The fifth lens 205 has the smallest focal length among the lenses, and the absolute value of the focal length of the fifth lens 205 can be 5 or greater and 8 or less.

[0303] The absolute value of the focal length of each lens can satisfy any of the following conditions.

[0304] Condition 1: |f1| > |f3|, |f4|, |f5|, |f6|, |f7|, |f8|, |f9|

[0305] Condition 2: |f1| > |f3| > |f4|, |f5|, |f6|, |f7|, |f8|, |f9|

[0306] Condition 3: |f1|, |f3| > |f4| > |f5|, |f6|, |f7|, |f8|, |f9|

[0307] Condition 4: |f1|, |f3|, |f4|, |f6|, |f7|, |f8|, |f9| > |f5|

[0308] Condition 5: |f1|, |f3|, |f4|, |f7| > |f6| > |f5|, |f8|, |f9|

[0309] Condition 6: |f1|, |f3|, |f4| > |f7| > |f5|, |f6|, |f8|, |f9|

[0310] Condition 7: |f1|, |f3|, |f4|, |f6|, |f7|, |f9| > |f8| > |f5|

[0311] Condition 8: |f1|, |f3|, |f4|, |f6|, |f7| > |f9| > |f5|, |f8|

[0312] The combined focal length f_LG1 of the first lens group LG1 can have a positive (+) sign. The combined refractive power of the first lens group LG1 can be positive (+). The combined focal length f_LG2 of the second lens group LG2 can have a negative (-) sign. The combined refractive power of the second lens group LG2 can be negative (-). The combined focal length f_LG3 of the third lens group LG3 can have a positive (+) sign. The combined refractive power of the third lens group LG3 can be positive (+). The combined focal length f_LG4 of the fourth lens group G4 can have a negative (-) sign. The combined refractive power of the fourth lens group G4 can be negative (-). In this way, light incident on the object side can move away from the optical axis and then converge back towards the optical axis, thus forming a stable optical path. The combined focal length f_LG5 of the fifth lens group LG5 can have a positive (+) sign. The combined refractive power of the fifth lens group LG5 can be positive (+).

[0313] When comparing the combined focal lengths of the first to fifth lens groups LG1, LG2, LG3, LG4, and LG5 in absolute values, the combined focal length of the first lens group LG1 can be the largest, and the combined focal length of the third lens group LG3 can be the smallest. The combined focal length relationship of the first to fifth lens groups LG1, LG2, LG3, LG4, and LG5 can satisfy |f_LG1| > |f_LG2| > |f_LG5| > |f_LG4| > |f_LG3|.

[0314] The thickness T1 of the first lens 201 can be minimum at the edge and maximum at the center, with the maximum thickness ranging from 1.5 to 2 times the minimum thickness. The thickness T3 of the third lens 203 can be minimum at the center and maximum at the edge, with the maximum thickness ranging from 1.5 to 2 times the minimum thickness. The thickness T4 of the fourth lens 204 can be minimum at the center and maximum at the edge, with the maximum thickness ranging from 1.5 to 2 times the minimum thickness. The thickness T5 of the fifth lens 205 can be maximum at the center and minimum at the edge, with the maximum thickness ranging from 2.5 to 3 times the minimum thickness. The thickness T6 of the sixth lens 206 can be minimum at the center and maximum at the edge, with the maximum thickness ranging from 1 to 1.5 times the minimum thickness. The thickness T7 of the seventh lens 207 can be maximum at the center and minimum at the edge, with the maximum thickness ranging from 1 to 1.5 times the minimum thickness. The thickness T8 of the eighth lens 208 can be minimum at the center and maximum at the edge, with the maximum thickness ranging from 2 to 3 times the minimum thickness. The thickness T9 of the ninth lens 209 can be maximum at the center and minimum at the edge, with the maximum thickness ranging from 1.5 to 2 times the minimum thickness.

[0315] The thickness of each lens can satisfy any of the following conditions.

[0316] Condition 1: 1.5 < CT1 / ET1 < 2, 0.5 < ET1 / CT1 < 1

[0317] Condition 2: 0.5 < CT3 / ET3 < 1, 1.5 < ET3 / CT3 < 2

[0318] Condition 3: 0.5 < CT4 / ET4 < 1, 1.5 < ET4 / CT4 < 2

[0319] Condition 4: 2.5 < CT5 / ET5 < 3, 0.1 < ET5 / CT5 < 0.5

[0320] Condition 5: 0.5 < CT6 / ET6 < 1, 1 < ET6 / CT6 < 1.5

[0321] Condition 6: 1 < CT7 / ET7 < 1.5, 0.5 < ET7 / CT7 < 1

[0322] Condition 7: 0.1 < CT8 / ET8 < 1, 2 < ET8 / CT8 < 3

[0323] Condition 8: 1.5 < CT9 / ET9 < 2, 0.5 < ET9 / CT9 < 1

[0324] Condition 9: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0325] Among the gaps G1-G8 between the lenses, the gap G1 between the first and second lenses 201 and 202 can have a maximum value at the center and a minimum value at the edge. The gap G2 between the second and third lenses 202 and 203 can have a maximum value at the edge and a minimum value at the center. The gap G3 between the third and fourth lenses 203 and 204 can have a minimum value at the edge and a maximum value at the center. The gap G4 between the fourth and fifth lenses 204 and 205 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 205 and 206 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 206 and 207 can have a maximum value at the center and a minimum value at the edge. The seventh gap G7 between the seventh and eighth lenses 207 and 208 can have a maximum value at the center and a minimum value at the edge. The eighth gap G8 between the eighth and ninth lenses 208 and 209 can have a maximum value at the center and a minimum value at the edge.

[0326] Figure 12 , Figure 13 and Figure 14 It is a graph showing the aberration characteristics at the wide-angle end, middle end and telephoto end of the optical system according to the second embodiment of the present invention. Figure 12 , Figure 13 and Figure 14 The aberration curves are graphs measuring spherical aberration (longitudinal spherical aberration), astigmatism, and distortion from left to right. Figure 12 , Figure 13 and Figure 14 In the graph, the X-axis represents focal length (mm) and distortion (%), while the Y-axis represents image height. Additionally, the spherical aberration graph is for light in the wavelength bands of approximately 435 nm, 486 nm, 546 nm, 587 nm, and 656 nm, and the astigmatism and distortion graphs are for light in the wavelength band of approximately 546 nm. Figure 12 , Figure 13 and Figure 14 The aberration diagram shows that the closer each curve is to the Y-axis at the wide-angle, mid-range, and telephoto ends, the better the aberration correction function. It can be seen that the optical system 1100 according to the second embodiment has measurements close to the Y-axis in almost all regions. That is, the optical system 1100 according to the second embodiment has enhanced resolution and good optical performance not only in the central portion of the field of view (FOV) but also in the peripheral portion.

[0327] An optical system according to a third embodiment of the present invention will be described.

[0328] Figure 15 This is a diagram showing the configuration of the optical system according to the third embodiment operating in the first mode; Figure 16 This is a diagram illustrating the configuration of the optical system according to the third embodiment operating in the second mode; Figure 17 This is a diagram showing the configuration of the optical system according to the third embodiment operating in the third mode; Figure 18 This is a table showing the aspherical coefficients of the lenses in the optical system according to the third embodiment; Figure 19 It is a graph showing the aberration characteristics of the optical system according to the third embodiment of the present invention operating in the first mode; Figure 20 It is a graph showing data on the aberration characteristics of an optical system according to a third embodiment of the present invention operating in the second mode; and Figure 21 This is a graph showing the aberration characteristics of an optical system according to a third embodiment of the present invention operating in the third mode.

[0329] refer to Figures 15 to 18 The optical system 1200 includes a lens unit, which may include a first lens 301 to a ninth lens 309. The first to ninth lenses 301-309 may be arranged sequentially along the optical axis OA of the optical system 1200. Light corresponding to the information of the object may pass through the first to ninth lenses 301-309 and the filter 500 and be incident on the image sensor 400.

[0330] The first lens 301 can be positioned closest to the object side. The first lens 301 can also be positioned furthest from the sensor side. The first lens 301 can have positive (+) refractive power in the optical axis direction OA. The first lens 301 can comprise plastic or glass material, and can be, for example, plastic material.

[0331] Relative to the optical axis direction OA, the first surface S1 on the object side of the first lens 301 is convex, and the second surface S2 on the sensor side can be concave. The first lens 301 can have a meniscus shape in which the object side is convex. The first lens 301 can have a meniscus shape in which the sensor side is concave. The first lens 301 can have an aspherical surface. The aspherical coefficients of the first and second surfaces S1 and S2 can be provided as follows: Figure 19 L1S1 and L1S2. The first lens 301 may be a D-cut lens. At least one or both of the first surface S1 and the second surface S2 of the first lens 301 may be configured such that there is no critical point from the optical axis to the end of the effective region.

[0332] The second lens 302 can be disposed as a second lens starting from the object side. The second lens 302 can be disposed as an eighth lens starting from the sensor side. The second lens 302 can be disposed between the first lens 301 and the third lens 303. The second lens 302 can comprise plastic or glass material. For example, the second lens 302 can be made of glass material. The object-side third surface S3 and the sensor-side fourth surface S4 of the second lens 302 can be formed as flat surfaces.

[0333] The second lens 302 can be a D-cut lens. The dimensions CA_L2S1 of the third surface S3 of the second lens 302 in the first direction (Y-axis direction) and CH_L2S1 in the second direction (X-axis direction) can be different. CH_L2S1 / CA_LS1 can satisfy a range of 0.1 or greater and 1 or less, and preferably can satisfy about 0.802. If it is less than the lower limit of the above conditions, it is difficult to manufacture the lens surface into a non-circular shape and it is difficult to control the distribution of incident light; and if it is greater than the upper limit of the above conditions, the effect of reducing the size of the optical system may be negligible.

[0334] The dimensions CA_L2S2 of the fourth surface S4 of the second lens 302 in the first direction (Y-axis direction) and CH_L2S2 in the second direction (X-axis direction) can be different. CH_L2S1 / CA_LS1 can satisfy a range of 0.1 or greater and 1 or less, and is preferably about 0.96. If it is less than the lower limit of the above conditions, it is difficult to manufacture the lens surface into a non-circular shape and it is difficult to control the distribution of incident light. If it exceeds the upper limit of the above conditions, the effect of reducing the size of the optical system may be negligible.

[0335] The second lens 302 can be a prism lens. The second lens 302 can be a right-angle prism lens. The second lens 302 can be a light path control component. The second lens 302 can change the path of light incident from the outside. The second lens 302 can include a reflector and a prism. The second lens 302 can rotate the light path by 90°. The second lens 302 includes an incident surface S3 for light incidence, a reflecting surface RS3 for reflecting incident light, and an exit surface S4 for emitting reflected light. The reflecting surface RS3 has a 45° tilt angle to reflect the principal ray of the incident light at a 90° angle, thereby reflecting the incident light to the second lens 202. The second lens 302 can reflect light incident in a first direction (Y-axis direction) and change the path of the light to a second direction (X-axis direction).

[0336] The third lens 303 can be the third one disposed from the object side. The third lens 303 can be the seventh one disposed from the sensor side. The third lens 303 can be disposed between the second lens 302 and the fourth lens 304. The third lens 303 can have negative (-) refractive power in the optical axis direction OA. The third lens 303 can include plastic or glass material. For example, the third lens 303 can be made of plastic material.

[0337] Relative to the optical axis, the object-side fifth surface S5 of the third lens 303 can be concave, and the sensor-side sixth surface S6 can also be concave. The third lens 303 can have concave shapes on both sides. The third lens 303 can have aspherical surfaces. The aspherical coefficients of the fifth surface S5 and the sixth surface S6 can be provided as follows: Figure 19 L3S1 and L3S2. At least one or both of the fifth surface S5 and the sixth surface S6 of the third lens 303 may be configured such that there is no critical point from the end of the optical axis to the effective region.

[0338] The fourth lens 304 can be disposed as the fourth lens starting from the object side. The fourth lens 304 can be disposed as the sixth lens starting from the sensor side. The fourth lens 304 can be disposed between the third lens 303 and the fifth lens 305. The fourth lens 304 can have negative (-) refractive power. The fourth lens 304 can comprise plastic or glass material. For example, the fourth lens 304 can be made of plastic material.

[0339] Relative to the optical axis, the seventh surface S7 on the object side of the fourth lens 304 can be convex, and the eighth surface S8 on the sensor side can be concave. The fourth lens 304 can have a meniscus shape in which the object side is convex. The fourth lens 304 can have a meniscus shape in which the sensor side is concave. The fourth lens 304 can have aspherical surfaces. The aspherical coefficients of the seventh surface S7 and the eighth surface S8 can be provided as follows: Figure 19 L4S1 and L4S2.

[0340] The seventh surface S7 of the fourth lens 104 may have a critical point at the end of the effective region from the optical axis. When the seventh surface S7 has a critical point, it may be located in the range of 65% to 80% of the effective radius from the optical axis, preferably in the range of 70% to 75% of the effective radius from the optical axis. The critical point of the seventh surface S7 may be located in the range of 1.5 mm to 3.0 mm from the optical axis, preferably in the range of 2.0 mm to 2.5 mm from the optical axis. The critical point of the seventh surface S7 may be a point where the sign of the gradient value relative to the optical axis and in the direction perpendicular to the optical axis changes from positive (+) to negative (-) or from negative (-) to positive (+), and may also represent a point where the gradient value is 0. In addition, the critical point of the seventh surface S7 may be a point where the gradient value increases and then decreases, or a point where the gradient value decreases and then increases, through the tangent of the lens surface. The eighth surface S8 of the fourth lens 104 may be configured to have no critical point at the end of the effective region from the optical axis.

[0341] An aperture stop can be positioned between the sensor-side lens of the second lens group LG2 and the object-side lens of the third lens group LG3. An aperture stop can be positioned between the fourth lens 304 and the fifth lens 305. An aperture stop can be positioned between the sensor-side lens of the third lens group LG3 and the object-side lens of the fourth lens group LG4. By using aperture stops, the TTL within the field of view can be reduced, allowing for miniaturization of the optical system. This prevents a decrease in the weight and yield of the optical system and improves production efficiency. Furthermore, miniaturization of the optical system is possible by reducing the TTL within a diagonal field of view (FOV) of 10 to 30 degrees.

[0342] The fifth lens 305 can be configured as the fifth lens from the object side. The fifth lens 305 can also be configured as the fifth lens from the sensor side. The fifth lens 305 can be positioned between the fourth lens 304 and the sixth lens 306. The fifth lens 305 can have positive (+) or negative (-) refractive power in the optical axis direction OA. The fifth lens 305 can have positive (+) refractive power. The fifth lens 305 can comprise plastic or glass material. For example, the fifth lens 305 can be made of plastic material.

[0343] Relative to the optical axis direction OA, the ninth surface S9 on the object side of the fifth lens 305 can be convex, and the tenth surface S10 on the sensor side can also be convex. The fifth lens 305 can have a shape where both sides are convex. The fifth lens 305 is made of plastic material and can have aspherical surfaces. The aspherical coefficients of the ninth surface S9 and the tenth surface S10 can be provided as follows: Figure 19 L5S1 and L5S2. At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 305 can be configured such that there is no critical point from the end of the optical axis to the effective region.

[0344] The sixth lens 306 can be configured as the sixth lens from the object side. The sixth lens 306 can also be configured as the third lens from the sensor side. The sixth lens 306 can be positioned between the fifth lens 305 and the seventh lens 307. The sixth lens 306 can have positive (+) or negative (-) refractive power in the optical axis direction OA. The sixth lens 306 can have negative (-) refractive power. The sixth lens 306 can comprise plastic or glass material. For example, the sixth lens 306 can be made of plastic material.

[0345] Relative to the optical axis direction OA, the eleventh surface S11 on the object side of the sixth lens 306 is concave, and the twelfth surface S12 on the sensor side can also be concave. The sixth lens 306 can have concave shapes on both sides. The sixth lens 306 can have aspherical surfaces. The aspherical coefficients of the eleventh surface S11 and the twelfth surface S12 can be provided as follows: Figure 19 L6S1 and L6S2. At least one or both of the eleventh surface S11 and the twelfth surface S12 of the sixth lens 306 can be configured such that there is no critical point from the optical axis to the end of the effective region.

[0346] The seventh lens 307 can be configured as the seventh from the object side. The seventh lens 307 can also be configured as the third from the sensor side. The seventh lens 307 can be positioned between the sixth lens 306 and the eighth lens 308. The seventh lens 307 can have positive (+) or negative (-) refractive power in the optical axis direction OA. The seventh lens 307 can have positive (+) refractive power. The seventh lens 307 can comprise plastic or glass material. For example, the seventh lens 307 can be made of plastic material.

[0347] Relative to the optical axis direction OA, the thirteenth surface S13 on the object side of the seventh lens 307 can be concave, and the fourteenth surface S14 on the sensor side can be convex. The seventh lens 307 can have a concave meniscus on the object side. The seventh lens 307 can have a convex meniscus on the sensor side. The seventh lens 307 can be made of plastic material and can have aspherical surfaces. The aspherical coefficients of the thirteenth surface S13 and the fourteenth surface S14 can be provided as follows: Figure 19 L7S1 and L7S2. At least one or both of the thirteenth surface S13 and the fourteenth surface S14 of the seventh lens 307 can be configured such that there is no critical point from the end of the optical axis to the effective region.

[0348] The eighth lens 308 can be configured as the eighth lens from the object side. The eighth lens 308 can also be configured as the second lens from the sensor side. The eighth lens 308 can be positioned between the sixth lens 306 and the ninth lens 309. The eighth lens 308 can have negative (-) refractive power. The eighth lens 308 can comprise plastic or glass material. For example, the eighth lens 308 can be made of plastic material.

[0349] Relative to the optical axis direction OA, the object-side fifteenth surface S15 of the eighth lens 308 may have a concave shape, and the sensor-side sixteenth surface S16 may also have a concave shape. The eighth lens 308 may have concave shapes on both sides. At least one or both of the fifteenth surface S15 and the sixteenth surface S16 may be aspherical. The aspherical coefficients of the fifteenth surface S15 and the sixteenth surface S16 may be provided as follows: Figure 19 L8S1 and L8S2. At least one or both of the fifteenth surface S15 and the sixteenth surface S16 of the eighth lens 308 can be configured such that there is no critical point from the end of the optical axis to the effective region.

[0350] The ninth lens 309 can be positioned closest to the sensor side. The ninth lens 309 can also be positioned furthest from the object side. The ninth lens 309 can have positive (+) refractive power. The ninth lens 309 can comprise plastic or glass material. For example, the ninth lens 309 can be made of plastic material.

[0351] Relative to the optical axis direction OA, the ninth lens 309 may have a convex shape on the object-side surface S17 and a convex shape on the sensor-side eighteenth surface S18. The ninth lens 309 may have convex shapes on both sides. At least one or both of the seventeenth surface S17 and the eighteenth surface S18 may be aspherical. The aspherical coefficients of the seventeenth surface S17 and the eighteenth surface S18 may be provided as follows: Figure 19 L9S1 and L9S2.

[0352] The seventeenth surface S17 of the ninth lens 309 can be configured to have no critical point at the end of the effective region from the optical axis. The eighteenth surface S18 of the ninth lens 309 can have a critical point at the end of the effective region from the optical axis. When the eighteenth surface S18 has a critical point, it can be located in the range of 50% to 65%, preferably 55% to 60%, of the effective radius from the optical axis. The critical point of the eighteenth surface S18 can be located in the range of 1.5 mm to 3.0 mm, preferably 2.0 mm to 2.5 mm, from the optical axis. The critical point of the eighteenth surface S18 is the point where the sign of the gradient value relative to the optical axis and in the direction perpendicular to the optical axis changes from positive (+) to negative (-) or from negative (-) to positive (+), and can also represent a point where the gradient value is 0. Furthermore, the critical point of the eighteenth surface S18 can be a point where the slope of the tangent through the lens surface increases and then decreases, or a point where the slope decreases and then increases.

[0353] [Table 7]

[0354] Table 7 shows the surface number, radius of curvature, center thickness of each lens or distance between lens surfaces, refractive index (nd), Abbe number (vd), effective radius, and focal length of the lenses according to the third embodiment of the present invention. Here, the units for radius of curvature and thickness or distance can be mm.

[0355] [Table 8]

[0356] Table 8 shows the variable lens gaps D1, D2, and D3 when the optical system according to the third embodiment of the present invention operates in any of the first to third modes. Here, the first mode can represent the wide-angle end, the second mode can represent the mid-range end, and the third mode can represent the telephoto end. The wide-angle end can be referred to as wide-angle, and the telephoto end can be referred to as telephoto. In the optical system according to the third embodiment of the present invention, the distance between adjacent lens groups can change during the process of changing the magnification from the first mode to the third mode. The first, second, and fifth lens groups LG1, LG2, and LG5 are fixed, and only the third and fourth lens groups LG3 and LG4 can be movable. The first, second, and fifth lens groups LG1, LG2, and LG5 are fixed groups, and the third and fourth lens groups LG3 and LG4 can be movable groups.

[0357] When switching from the first mode to the second mode, the distance D1 between the second lens group LG2 and the third lens group LG3 can be decreased, the distance D2 between the third lens group LG3 and the fourth lens group LG4 can be increased, and the distance D3 between the fourth lens group LG4 and the fifth lens group LG5 can be increased.

[0358] When switching from the second mode to the third mode, the distance D1 between the second lens group LG2 and the third lens group LG3 can be decreased, the distance D2 between the third lens group LG3 and the fourth lens group LG4 can be increased, and the distance D3 between the fourth lens group LG4 and the fifth lens group LG5 can be increased.

[0359] When switching from the first mode to the third mode, the distance D1 between the second lens group LG2 and the third lens group LG3 can be decreased, the distance D2 between the third lens group LG3 and the fourth lens group LG4 can be increased, and the distance D3 between the fourth lens group LG4 and the fifth lens group LG5 can be increased.

[0360] The travel length of the third lens group LG3 can be between 5mm and 7mm, and preferably about 5.610mm. The travel length of the fourth lens group LG4 can be between 4mm and 5mm, and preferably about 4.350mm. The travel length of the third lens group LG3 can be greater than that of the fourth lens group LG4. The third lens group LG3 and the fourth lens group LG4 can have different moving speeds. The moving speed of the third lens group LG3 can be greater than that of the fourth lens group LG4. In the third embodiment, the magnification at the wide-angle end and the telephoto end can be in the range of 1.5x to 2x, and can be about 1.99x.

[0361] [Table 9]

[0362] Table 9 shows the terms of the above mathematical formula in the optical system 1200 of the third embodiment at each of the wide-angle and telephoto ends of the optical system 1200, and relates to: F (mm), effective focal length; BFL (mm), back focal length; EPD (mm); SD (mm), optical axis distance from the stop to the eighteenth surface S18; Fno; HFOV (degrees) and focal lengths f1-f9 (mm) of the first to ninth lenses 301-309; ET1-ET9, edge thickness; f_LG1, f_LG2, f_LG3, f_LG4 and f_LG5 (mm), focal lengths of the first to fifth lens groups LG1, LG2, LG3, LG4 and LG5; LG3_s troke, the stroke length of the third lens group LG3; LG4_stroke, the stroke length of the fourth lens group LG4; TTL (mm), the total optical axis distance of the optical system 1200; ImgH (mm); CA_Max, the maximum effective diameter of the first to ninth lenses (301-309); CA_Min, the minimum effective diameter; CA_Aver, the average effective diameter; maximum center thickness (L_CT_max), minimum center thickness (L_CT_min), and average center thickness (L_CT_aver); TD_LG1, TD_LG2, TD_LG3, TD_LG4, TD_LG5, the length of each lens group in the optical axis direction, etc.

[0363] The center thicknesses of the first to ninth lenses 301-309 are represented by CT1 to CT9, the edge thicknesses at the ends of the effective areas of each lens are represented by ET1 to ET9, the center gaps between two adjacent lenses are represented by CG1 to CG8, and the edge gaps between the edges of each lens are represented by EG1 to EG8. The back focal length (BFL) is the optical axis distance from the image sensor 400 to the center of the last lens. The TTL is the optical axis distance from the center of the first surface S1 of the first lens 301 to the upper surface of the image sensor 400. In the following description, some descriptions regarding the dimensional relationships of the second lens 102, which serves as a prism lens, are omitted.

[0364] When comparing the absolute values ​​of the radii of curvature of each lens, the radius of curvature of the second surface S2 of the first lens 301 in the optical axis direction OA can be the largest among the lenses, and the radius of curvature of the sixteenth surface S16 of the eighth lens 308 can be the smallest among the lenses. The absolute value of the radius of curvature of the first surface S1 of the first lens 301 can be smaller than the absolute value of the radius of curvature of the second surface S2. The absolute value of the radius of curvature of the fifth surface S5 of the third lens 303 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 304 can be greater 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 305 can be smaller 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 306 can be smaller 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 307 can be greater than the absolute value of the radius of curvature of the fourteenth surface S14. The absolute value of the radius of curvature of the fifteenth surface S15 of the eighth lens 308 can be greater than the absolute value of the radius of curvature of the sixteenth surface S16. The absolute value of the radius of curvature of the seventeenth surface S17 of the ninth lens 309 can be less than the absolute value of the radius of curvature of the eighteenth surface S18.

[0365] The ratio of the radii of curvature of each lens can satisfy the following condition.

[0366] Condition 1: 0.1 < |L1R1 / L1R2| < 0.5

[0367] Condition 2: 1 < |L3R1 / L3R2| < 1.5

[0368] Condition 3: 3 < |L4R1 / L4R2| < 5

[0369] Condition 4: 0.5 < |L5R1 / L5R2| < 1

[0370] Condition 5: 0.1 < |L6R1 / L6R2| < 0.5

[0371] Condition 6: 1.5 < |L7R1 / L7R2| < 2

[0372] Condition 7: 5 < |L8R1 / L8R2| < 10

[0373] Condition 8: 0.5 < |L9R1 / L9R2| < 1

[0374] When interpreting the center thickness of a lens relative to the optical axis, the center thickness CT5 of the fifth lens 305 is the largest, while the center thickness CT3 of the third lens 303 and the center thickness CT4 of the fourth lens 304 are the smallest. The difference between the maximum and minimum center thickness of a lens can be in the range of 2 mm or greater and 3 mm or less.

[0375] The center thickness of each lens can satisfy any of the following conditions.

[0376] Condition 1: CT5, CT6, CT7, CT9 > CT1 > CT3, CT4, CT8

[0377] Condition 2: CT1, CT5, CT6, CT7, CT8, CT9 > CT3 = CT4

[0378] Condition 3: CT5 > CT1, CT3, CT4, CT6, CT8, CT7, CT9

[0379] Condition 4: CT5, CT7, CT9 > CT6 > CT1, CT3, CT4, CT8

[0380] Condition 5: CT5 > CT7 > CT1, CT3, CT4, CT6, CT8, CT9

[0381] Condition 6: CT1, CT5, CT6, CT7, CT9 > CT8 > CT3, CT4

[0382] Condition 7: CT5, CT7 > CT9 > CT1, CT3, CT4, CT6, CT8

[0383] During zooming, the gaps CG1 between the first lens 301 and the second lens 302, CG2 between the second lens 302 and the third lens 303, CG3 between the third lens 303 and the fourth lens 304, CG5 between the fifth lens 305 and the sixth lens 306, and CG7 between the seventh lens 307 and the eighth lens 308 remain constant, while the gaps CG4 between the fourth lens 304 and the fifth lens 305, CG6 between the sixth lens 306 and the seventh lens 307, and CG8 between the eighth lens 308 and the ninth lens 309 can vary. Among the constant center gaps between the lenses, the center gap CG2 between the second lens 302 and the third lens 303 is the largest, and the center gap CG5 between the fifth lens 305 and the sixth lens 306 can be the smallest. The difference between the largest and smallest center gaps among the spaced lens gaps can be 0.7 mm or greater, for example, in the range of 0.9 mm to 1 mm.

[0384] The center gap between each lens can meet the following conditions.

[0385] Condition 1: CG2 > CG1 > CG3, CG5, CG7

[0386] Condition 2: CG2 > CG1, CG3, CG5, CG7

[0387] Condition 3: CG1, CG2, CG7 > CG3 > CG5

[0388] Condition 4: CG1, CG2, CG3, CG7 > CG5

[0389] Condition 5: CG1, CG2 > CG7 > CG3, CG5

[0390] Regarding the effective diameter, the lens with the largest effective diameter can be the ninth lens 309. Here, the effective diameter is the average of the effective diameters of the object-side surface and the sensor-side surface of each lens. The lens surface with the largest effective diameter can be the seventeenth surface S17 of the ninth lens 309. The lens with the smallest effective diameter can be the sixth lens 306. The lens surface with the smallest effective diameter can be the twelfth surface S12 of the sixth lens 306.

[0391] The effective diameter of each lens can satisfy any one of the following conditions.

[0392] Condition 1: CA_L9 > CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7, CA_L8

[0393] Condition 2: CA_L1, CA_L9 > CA_L2 > CA_L3, CA_L4, CA_L5, CA_L6, CA_L7, CA_L8

[0394] Condition 3: CA_L1, CA_L2, CA_L5, CA_L8, CA_L9 > CA_L3 > CA_L4, CA_L6, CA_L7

[0395] Condition 4: CA_L1, CA_L2, CA_L3, CA_L5, CA_L8, CA_L9 > CA_L4 > CA_L6, CA_L7

[0396] Condition 5: CA_L1, CA_L2, CA_L8, CA_L9 > CA_L5 > CA_L3, CA_L4, CA_L6, CA_L7

[0397] Condition 6: CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L7, CA_L8, CA_L9 > CA_L6

[0398] Condition 7: CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L8, CA_L9 > CA_L7 > CA_L6

[0399] Condition 8: CA_L1, CA_L2, CA_L9 > CA_L8 > CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0400] Condition 9: CA_L9 > CA_L1, CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7, CA_L8

[0401] When interpreting refractive index, the second lens 302 has the highest refractive index among the lenses and can be greater than 1.6, for example, greater than 1.7. The third lens 303, the fifth lens 305, and the eighth lens 308 have the lowest refractive indices among the lenses and can be less than 1.6, for example, less than 1.55. The difference between the maximum and minimum refractive indices can be 0.15 or greater.

[0402] The refractive index of each lens can satisfy any of the following conditions.

[0403] Condition 1: n2 > n1 = n7 = n9 > n3, n4, n5, n6, n8

[0404] Condition 2: n2 > n1, n3, n4, n5, n6, n7, n8, n9

[0405] Condition 3: n1, n2, n4, n6, n7, n9 > n3 = n5 = n8

[0406] Condition 4: n1, n2, n7, n9 > n4 > n3, n5, n6, n8

[0407] Condition 5: n1, n2, n4, n7, n9 > n6 > n3, n5, n8

[0408] When comparing Abbe numbers, the third lens 303, the fifth lens 305, and the eighth lens 308 have the highest Abbe numbers among the lenses, and these can be 50 or greater. The first lens 301, the seventh lens 307, and the ninth lens 309 have the lowest Abbe numbers among the lenses, and these can be 20 or less. The difference between the maximum refractive index and the minimum Abbe number can be 30 or greater.

[0409] The Abbe number of each lens can satisfy any of the following conditions.

[0410] Condition 1: v2, v3, v4, v5, v6, v8 > v1 = v7 = v9

[0411] Condition 2: v3, v5, v8 > v2 > v1, v4, v6, v7, v9

[0412] Condition 3: v3 = v5 = v8 > v1, v2, v4, v6, v7, v9

[0413] Condition 4: v2, v3, v5, v6, v8 > v4 > v1, v7, v9

[0414] Condition 5: v2, v3, v5, v8 > v6 > v1, v4, v7, v9

[0415] The focal lengths F1, F5, F7, and F9 of the first, fifth, seventh, and ninth lenses 301, 305, 307, and 309 can have a positive (+) refractive power. The focal lengths F3, F4, F6, and F8 of the third, fourth, sixth, and eighth lenses 303, 304, 306, and 308 can have a negative (-) refractive power.

[0416] When comparing focal lengths in absolute terms, the first lens 301 has the largest focal length among the lenses, and it can be 20 or greater and 30 or less. The fifth lens 305 has the smallest focal length among the lenses, and the absolute value of the focal length of the fifth lens 305 can be 5 or greater and 8 or less.

[0417] The absolute value of the focal length of each lens can satisfy any of the following conditions.

[0418] Condition 1: |f1| > |f3|, |f4|, |f5|, |f6|, |f7|, |f8|, |f9|

[0419] Condition 2: |f1|, |f4| > |f3| > |f5|, |f6|, |f7|, |f8|, |f9|

[0420] Condition 3: |f1| > |f4| > |f3|, |f5|, |f6|, |f7|, |f8|, |f9|

[0421] Condition 4: |f1|, |f3|, |f4|, |f6|, |f7|, |f8|, |f9| > |f5|

[0422] Condition 5: |f1|, |f3|, |f4|, |f7|, |f9| > |f6| > |f5|, |f8|

[0423] Condition 6: |f1|, |f3|, |f4|, |f9| > |f7| > |f5|, |f6|, |f8|

[0424] Condition 7: |f1|, |f3|, |f4|, |f6|, |f7|, |f9| > |f8| > |f5|

[0425] Condition 8: |f1|, |f3|, |f4| > |f9| > |f5|, |f6|, |f7|, |f8|

[0426] The combined focal length f_LG1 of the first lens group LG1 can have a positive (+) sign. The combined refractive power of the first lens group LG1 can be positive (+). The combined focal length f_LG2 of the second lens group LG2 can have a negative (-) sign. The combined refractive power of the second lens group LG2 can be negative (-). The combined focal length f_LG3 of the third lens group LG3 can have a positive (+) sign. The combined refractive power of the third lens group LG3 can be positive (+). The combined focal length f_LG4 of the fourth lens group G4 can have a negative (-) sign. The combined refractive power of the fourth lens group G4 can be negative (-). In this way, light incident on the object side can move away from the optical axis and then converge back towards the optical axis, thus forming a stable optical path. The combined focal length f_LG5 of the fifth lens group LG5 can have a positive (+) sign. The combined refractive power of the fifth lens group LG5 can be positive (+).

[0427] When comparing the combined focal lengths of the first to fifth lens groups LG1, LG2, LG3, LG4, and LG5 in absolute values, the combined focal length of the first lens group LG1 can be the largest, and the combined focal length of the third lens group LG3 can be the smallest. The combined focal length relationship of the first to fifth lens groups LG1, LG2, LG3, LG4, and LG5 can satisfy |f_LG1| > |f_LG5| > |f_LG4| > |f_LG2| > |f_LG3|.

[0428] The thickness T1 of the first lens 301 can be minimum at the edge and maximum at the center, with the maximum thickness ranging from 1.5 to 2 times the minimum thickness. The thickness T3 of the third lens 303 can be minimum at the center and maximum at the edge, with the maximum thickness ranging from 1.5 to 2 times the minimum thickness. The thickness T4 of the fourth lens 304 can be minimum at the center and maximum at the edge, with the maximum thickness ranging from 1 to 2 times the minimum thickness. The thickness T5 of the fifth lens 305 can be maximum at the center and minimum at the edge, with the maximum thickness ranging from 2.5 to 3 times the minimum thickness. The thickness T6 of the sixth lens 306 can be minimum at the center and maximum at the edge, with the maximum thickness ranging from 1 to 1.5 times the minimum thickness. The thickness T7 of the seventh lens 307 can be maximum at the center and minimum at the edge, with the maximum thickness ranging from 1 to 1.5 times the minimum thickness. The thickness T8 of the eighth lens 308 can be minimum at the center and maximum at the edge, with the maximum thickness ranging from 2.5 to 3 times the minimum thickness. The thickness T9 of the ninth lens 309 can be maximum at the center and minimum at the edge, with the maximum thickness ranging from 1 to 1.5 times the minimum thickness.

[0429] The thickness of each lens can satisfy any of the following conditions.

[0430] Condition 1: 1.5 < CT1 / ET1 < 2, 0.5 < ET1 / CT1 < 1

[0431] Condition 2: 0.5 < CT3 / ET3 < 1, 1.5 < ET3 / CT3 < 2

[0432] Condition 3: 0.5 < CT4 / ET4 < 1, 1 < ET4 / CT4 < 2

[0433] Condition 4: 2.5 < CT5 / ET5 < 3, 0.1 < ET5 / CT5 < 0.5

[0434] Condition 5: 0.5 < CT6 / ET6 < 1, 1 < ET6 / CT6 < 1.5

[0435] Condition 6: 1 < CT7 / ET7 < 1.5, 0.5 < ET7 / CT7 < 1

[0436] Condition 7: 0.1 < CT8 / ET8 < 1, 2.5 < ET8 / CT8 < 3

[0437] Condition 8: 1 < CT9 / ET9 < 1.5, 0.5 < ET9 / CT9 < 1

[0438] Condition 9: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0439] Among the gaps G1-G8 between the lenses, the gap G1 between the first and second lenses 301 and 302 can have a maximum value at the center and a minimum value at the edge. The gap G2 between the second and third lenses 302 and 303 can have a minimum value at the edge and a maximum value at the center. The gap G3 between the third and fourth lenses 303 and 304 can have a minimum value at the edge and a maximum value at the center. The gap G4 between the fourth and fifth lenses 304 and 305 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 305 and 306 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 306 and 307 can have a maximum value at the center and a minimum value at the edge. The seventh gap G7 between the seventh and eighth lenses 307 and 308 can have a maximum value at the center and a minimum value at the edge. The eighth gap G8 between the eighth and ninth lenses 308 and 309 can have a maximum value at the center and a minimum value at the edge.

[0440] Figure 19 , Figure 20 and Figure 21 It is a graph showing the aberration characteristics at the wide-angle end, middle end and telephoto end of the optical system according to the third embodiment of the present invention. Figure 19 , Figure 20 and Figure 21 The aberration curves are graphs measuring spherical aberration (longitudinal spherical aberration), astigmatism, and distortion from left to right. Figure 19 , Figure 20 and Figure 21 In the graph, the X-axis represents focal length (mm) and distortion (%), while the Y-axis represents image height. Additionally, the spherical aberration graph is for light in the wavelength bands of approximately 435 nm, 486 nm, 546 nm, 587 nm, and 656 nm, and the astigmatism and distortion graphs are for light in the wavelength band of approximately 546 nm. Figure 19 , Figure 20 and Figure 21 The aberration diagram shows that the closer each curve is to the Y-axis at the wide-angle, mid-range, and telephoto ends, the better the aberration correction function. It can be seen that the optical system 1200 according to the third embodiment has measurements close to the Y-axis in almost all regions. That is, the optical system 1200 according to the third embodiment has enhanced resolution and good optical performance not only in the central portion of the field of view (FOV) but also in the peripheral portion.

[0441] The optical systems 1000, 1100, and 1200 according to the first to third embodiments disclosed above can satisfy at least one, two, or more of the mathematical formulas described below. Therefore, the optical systems 1000, 1100, and 1200 according to the first to third embodiments can have enhanced optical characteristics. For example, when the optical systems 1000, 1100, and 1200 satisfy at least one mathematical expression, the optical systems 1000, 1100, and 1200 can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only in the central portion of the field of view (FOV) but also in the peripheral portion. Furthermore, the optical systems 1000, 1100, and 1200 can have enhanced resolution. Additionally, the lens thickness in the optical axis direction OA and the gap between adjacent lenses in the optical axis direction OA described in the mathematical formulas can be referenced to the first embodiment described above.

[0442] [Mathematical Expression 1]

[0443] 0.1 < TD_LG2 / TD_LG3 < 0.5

[0444] Mathematical expression 1 defines the relationship between the length TD_LG2 of the second lens group LG2 along the optical axis and the length TD_LG3 of the third lens group LG3 along the optical axis. Mathematical expression 1 is a condition used to reduce aberrations and improve optical performance.

[0445] The second lens group LG2 and the third lens group LG3, satisfying mathematical expression 1, can appropriately correct astigmatism and coma. Furthermore, the overall length of the zoom optical system with an appropriate zoom magnification can be reduced. In the first to third embodiments, mathematical expression 1 preferably satisfies 0.2 < TD_LG2 / TD_LG3 < 0.4.

[0446] [Mathematical Expression 2]

[0447] 1 < TD_LG3 / TD_LG4 < 1.5

[0448] Mathematical expression 2 defines the relationship between the length TD_LG3 of the third lens group LG3 along the optical axis and the length TD_LG4 of the fourth lens group LG4 along the optical axis. Mathematical expression 2 is a condition used to reduce aberrations and improve optical performance.

[0449] The third lens group LG3 and the fourth lens group LG4, which satisfy mathematical expression 2, can appropriately correct astigmatism and coma. Furthermore, the overall length of the zoom optical system with an appropriate zoom magnification can be reduced. In the first to third embodiments, mathematical expression 2 preferably satisfies 1 < TD_LG3 / TD_LG4 < 1.3.

[0450] [Mathematical Expression 3]

[0451] 1.5 < BFL_Min < 2.5

[0452] In mathematical expression 3, BFL is the optical axis distance from the center of the image sensor 400 to the sensor side of the last lens. When mathematical expression 3 is satisfied, the mounting space for the filter 500 and the cover glass can be ensured, the assemblability of the components can be improved by the gap between the image sensor 400 and the last lens, and the reliability of the assembly can be improved. In the first to third embodiments, mathematical expression 3 preferably satisfies 1.7 < BFL_Min < 2.2. When BFL is less than the range of mathematical expression 3, some light traveling to the image sensor may not be transmitted to the image sensor, which may lead to a reduction in resolution. When BFL exceeds the range of mathematical expression 3, stray light may be introduced, which may degrade the aberration characteristics of the optical system.

[0453] [Mathematical Expression 4]

[0454] 30 < Ave_ABV < 40

[0455] In mathematical expression 4, Ave_ABV is the average Abbe number of the lenses included in optical systems 1000, 1100, and 1200. When mathematical expression 4 is satisfied, optical performance can be enhanced by appropriately setting factors affecting chromatic aberration. In the first to third embodiments, mathematical expression 4 can preferably satisfy 30 < Ave_ABV < 35.

[0456] [Mathematical Expression 5]

[0457] 1.6 < Ave_Ind < 1.7

[0458] In mathematical expression 5, Ave_Ind is the average refractive index of the lenses included in optical systems 1000, 1100, and 1200. When mathematical expression 5 is satisfied, optical performance can be enhanced by appropriately setting factors affecting chromatic aberration. In the first to third embodiments, mathematical expression 4 can preferably satisfy 1.6 < Ave_Ind < 1.65.

[0459] [Mathematical Expression 6]

[0460] 15 < f_wide < 17

[0461] In mathematical expression 6, f_wide is the total focal length of optical systems 1000, 1100, and 1200 in the first mode (wide end). Mathematical expression 6 is a condition used to limit the zoom optical performance.

[0462] If the upper limit of mathematical expression 6 is exceeded, optical performance becomes difficult to ensure due to chromatic aberration at the telephoto end, and the movement of each lens group increases significantly during zooming, making mechanical miniaturization difficult. If the lower limit of mathematical expression 6 is less than the lower limit, there is a problem of increased overall sensitivity of the optical system. A zoom optical system that satisfies mathematical expression 6 can ensure practically useful optical performance. In the first to third embodiments, mathematical expression 6 can preferably satisfy 15 < f_wide < 16.

[0463] The zoom ratio of the optical systems 1000, 1100, and 1200 according to the first to third embodiments can be approximately 4x to approximately 8x. The zoom ratio is calculated by conversion based on EFL 35mm. The diagonal size of the image sensor at EFL 35mm can be 43.3mm. EFL is affected by the image sensor size, and even with the same zoom ratio, it can be represented as different EFLs depending on the image sensor size.

[0464] Typically, a camera module with a 1x zoom ratio and an EFL 35mm focal length can have a focal length of 24mm, while one with a 2x zoom ratio can have a focal length of 48mm. Therefore, the EFL_wide based on an EFL 35mm focal length is 43.3 × 15.93 / 7.1 = 97.15mm, and the EFL_tele is 43.3 × 31.85 / 7.1 = 194.24mm. Based on the zoom ratio, the zoom ratio can be approximately 4x to approximately 8x.

[0465] [Mathematical Expression 7]

[0466] 1.5 < f_tele / f_wide < 2.5

[0467] Mathematical expression 7 defines the relationship between the total focal length f_tele (tele at the telephoto end) of the optical system 1000, 1100, and 1200 in the third mode and the total focal length f_wide (wide at the wide-angle end) of the optical system 1000, 1100, and 1200 in the first mode. f_tele / f_wide can be referred to as the magnification or zoom ratio of the zoom lens optical system. Mathematical expression 7 is a condition used to limit the zoom optical performance.

[0468] If the upper limit of mathematical expression 7 is exceeded, optical performance becomes difficult to ensure due to chromatic aberration at the telephoto end, and the movement of each lens group increases significantly during zooming, making mechanical miniaturization difficult. If the lower limit of mathematical expression 7 is exceeded, performance as a zoom optical system becomes difficult to ensure. A zoom optical system that satisfies mathematical expression 7 can ensure practically useful optical performance. In the first to third embodiments, mathematical expression 7 can preferably satisfy 1.7 < f_tele / f_wide < 2.

[0469] [Mathematical Expression 8]

[0470] 1 < |f_LG2 / f_LG3| < 2

[0471] Mathematical expression 8 defines the relationship between the focal length f_LG2 of the second lens group LG2 and the focal length f_LG3 of the third lens group LG3. Mathematical expression 8 is a condition used to reduce aberrations and improve optical performance.

[0472] The second lens group LG2 and the third lens group LG3, satisfying mathematical expression 8, can appropriately correct astigmatism and coma. Furthermore, the zoom optical system has a zoom ratio of approximately 1.9x and can reduce the overall length of the optical system. Mathematical expression 8 in the first to third embodiments preferably satisfies 1 < |f_LG2 / f_LG3| < 1.6.

[0473] [Mathematical Expression 9]

[0474] 0.1 < |f_LG3 / f_LG4| < 1

[0475] Mathematical expression 9 defines the relationship between the focal length f_LG3 of the third lens group LG3 and the focal length f_LG4 of the fourth lens group LG4. Mathematical expression 9 is a condition used to reduce aberrations and improve optical performance.

[0476] The third lens group LG3 and the fourth lens group LG4, satisfying mathematical expression 9, can appropriately correct astigmatism and coma. Furthermore, the zoom optical system has a zoom ratio of approximately 1.9x and can reduce the overall length of the optical system. Mathematical expression 9 can preferably satisfy 0.5 < |f_LG3 / f_LG4| < 1 in the first to third embodiments.

[0477] [Mathematical Expression 10]

[0478] 5 < LG3_stroke < 7

[0479] Mathematical expression 10 can set the range of the stroke length LG3_stroke of the third lens group LG3. If it exceeds the upper limit of mathematical expression 10, the stroke length of the third lens group LG3 becomes longer during focusing, making it difficult to miniaturize the zoom lens. If it is less than the lower limit of mathematical expression 10, the performance of the zoom optical system may degrade. In the first to third embodiments, mathematical expression 10 can preferably satisfy 5 < LG3_stroke < 6.5.

[0480] [Mathematical Expression 11]

[0481] 4 < LG4_stroke < 7

[0482] Mathematical expression 11 can set the range of the stroke length LG4_stroke of the fourth lens group LG4. If it exceeds the upper limit of mathematical expression 11, the stroke length of the fourth lens group LG4 becomes longer during focusing, making it difficult to miniaturize the zoom lens. If it is less than the lower limit of mathematical expression 11, the performance of the zoom optical system may degrade. In the first to third embodiments, mathematical expression 11 can preferably satisfy 4 < LG4_stroke < 6.5.

[0483] [Mathematical Expression 12]

[0484] 15 < F1 < 65

[0485] In mathematical expression 12, F1 is the focal length of the first lenses 101, 201, and 301. When mathematical expression 12 is satisfied, optical systems 1000, 1100, and 1200 can have a set viewing angle and an appropriate focal length, and the viewing angle can be set large within an appropriate TTL range. When it is less than the lower limit of mathematical expression 12, the effective diameter or TTL of the lens may become longer, which may lead to the problem of an enlarged imaging lens system. When it is greater than the upper limit of mathematical expression 12, the effect of the first lenses 101, 201, and 301 becomes smaller in the overall optical system, and the refractive power of the lens needs to be increased, which leads to the problem of difficulty in correcting spherical aberration or distortion aberration. In the first to third embodiments, mathematical expression 12 can preferably satisfy 20 < F1 < 40.

[0486] [Mathematical Expression 13]

[0487] 0.5 < CT1 < 3

[0488] In mathematical expression 13, CT1 is the center thickness of the first lenses 101, 201, and 301. When mathematical expression 13 is satisfied, it prevents the thickness of the optical systems 1000, 1100, and 1200 from increasing in the first direction (y-axis direction), and enables a compact continuous zoom optical system. In the first to third embodiments, mathematical expression 13 can preferably satisfy 1. <CT1 < 2.5。

[0489] [Mathematical Expression 14]

[0490] 30 < TTL < 40

[0491] In mathematical expression 14, the total track length TTL represents the distance (mm) from the center of the first surface S1 of the first lenses 101, 201, and 301 to the upper surface of the image sensor 400 along the optical axis direction OA. In the first to third embodiments, mathematical expression 14 can preferably satisfy 33 < TTL < 37.

[0492] [Mathematical Expression 15]

[0493] 6 < ImgH < 8

[0494] In mathematical expression 15, ImgH represents the maximum diagonal length of the image sensor 400. Mathematical expression 15 can set the diagonal size ImgH of the image sensor 400 and provide an optical system with a large moving image sensor size. In the first to third embodiments, mathematical expression 15 can preferably satisfy 6.5 < ImgH < 7.5.

[0495] [Mathematical Expression 16]

[0496] 2 < Fno_wide < 3

[0497] Mathematical expression 16 can set the range of Fno in the first mode (which is the wide-angle end). When mathematical expression 16 is satisfied, an image with suitable brightness can be provided, and a lot of light can be received by the image sensor. In the first to third embodiments, mathematical expression 16 can preferably satisfy 2.5 < Fno_wide < 3.

[0498] [Mathematical Expression 17]

[0499] 20 < FOV_wide < 30

[0500] In mathematical expression 17, the range of the field of view (FOV_wide) in the first mode (which is the wide end) can be set. Mathematical expression 17 can provide a field of view suitable for a mobile optical system. In the first to third embodiments, the FOV can preferably satisfy 23 < HFOV_wide < 28.

[0501] [Mathematical Expression 18]

[0502] 3 < TTL / CA_max < 5

[0503] In mathematical expression 18, CA_max represents the maximum effective diameter (mm) among the object-side and sensor-side of the plurality of lenses, and the total track length (TTL) represents the distance (mm) along the optical axis direction OA from the vertex of the first surface S1 of the first lenses 101, 201, and 301 to the upper surface of the image sensor 400. Mathematical expression 18 sets the relationship between the total optical axis length and the maximum effective diameter of the optical system to provide an improved mobile optical system. In the first to third embodiments, mathematical expression 18 may preferably satisfy 3.5 < TTL / CA_max < 4.5.

[0504] [Mathematical Expression 19]

[0505] 4 < TTL / ImgH < 6

[0506] In mathematical expression 19, the total track length (TTL) represents the distance (mm) from the vertex of the first surface S1 of the first lens to the upper surface of the image sensor 400 along the optical axis direction OA, and ImgH represents the maximum diagonal length of the image sensor 400. When mathematical expression 19 is satisfied, optical systems 1000, 1100, and 1200 can have a TTL suitable for moving the image sensor 400, thereby providing improved image quality. When it is less than the lower limit of mathematical expression 2, the refractive power of the lens needs to be increased, making it difficult to correct spherical aberration or distortion aberration, and when it exceeds the upper limit of mathematical expression 2, the effective diameter or TTL of the lens becomes longer, which may lead to the problem of an enlarged imaging lens system. In the first to third embodiments, mathematical expression 19 can preferably satisfy 4.5 < TTL / ImgH < 5.5.

[0507] [Mathematical Expression 20]

[0508] 1.5 < f_wide / ImgH < 3

[0509] In mathematical expression 20, f_wide is the total effective focal length of optical systems 1000, 1100, and 1200 in the first mode (which is the wide-angle end), and ImgH represents the maximum diagonal length of image sensor 400. When mathematical expression 21 is satisfied, the moving image sensor 400 can have enhanced aberration characteristics in size. In the first to third embodiments, mathematical expression 20 can preferably satisfy 2 < F_wide / ImgH < 2.5.

[0510] [Mathematical Expression 21]

[0511] 3 < f_tele / ImgH < 5

[0512] In mathematical expression 21, f_tele is the total effective focal length of optical systems 1000, 1100, and 1200 in the third mode (which is the telephoto end (tele)), and ImgH represents the maximum diagonal length of image sensor 400. When mathematical expression 21 is satisfied, the moving image sensor 400 can have enhanced aberration characteristics in size. In the first to third embodiments, mathematical expression 21 can preferably satisfy 4 < f_tele / ImgH < 5.

[0513] [Mathematical Expression 22]

[0514] 0.1 < ΣCT / TTL < 1

[0515] Mathematical expression 22 can define the relationship between the sum of the center thicknesses ΣCT of the lenses and the distance TTL along the optical axis direction OA from the vertex of the first surface S1 of the first lens to the upper surface of the image sensor 400. If the upper limit of mathematical expression 22 is exceeded, the number of lenses increases, and the movement of the moving lens group in the zoom optical system may become unfavorable. If the lower limit of mathematical expression 22 is less than the lower limit, the magnification performance of the zoom lens optical system may deteriorate. In the first to third embodiments, mathematical expression 22 can preferably satisfy 0.3 < ΣCT / TTL < 0.7.

[0516] [Mathematical Expression 23]

[0517] 0.1 < ΣCG / TTL < 1

[0518] Mathematical expression 23 can define the relationship between the sum of gaps ΣCG between adjacent lenses and the distance TTL from the vertex of the first surface S1 of the first lens to the upper surface of the image sensor 400 along the optical axis direction OA. If the upper limit of mathematical expression 23 is exceeded, the moving distance of the moving lens group in the zoom lens optical system becomes larger, and therefore the current consumption during zoom operation may increase. If the lower limit of mathematical expression 23 is less than the lower limit, the magnification performance of the zoom lens optical system may deteriorate. In the first to third embodiments, mathematical expression 23 can preferably satisfy 0.1 < ΣCG / TTL < 0.5.

[0519] [Mathematical Expression 24]

[0520] 1 < ΣCT / ΣCG < 2

[0521] Mathematical expression 24 defines the relationship between the sum of the center thicknesses ΣCT of the lenses and the sum of the gaps between adjacent lenses ΣCG. If the upper limit of mathematical expression 24 is exceeded, the number of lenses increases, which may be detrimental to the movement of the moving lens group in the zoom optical system. If the lower limit of mathematical expression 24 is less than the lower limit, the magnification performance of the zoom lens optical system may deteriorate. In the first to third embodiments, mathematical expression 24 preferably satisfies 1 < ΣCT / ΣCG < 1.5.

[0522] [Mathematical Expression 25]

[0523] 1 < CA_max / CA_min < 2

[0524] In mathematical expression 25, CA_max represents the maximum effective diameter on the object-side and sensor-side surfaces of the lens, and CA_min represents the minimum effective diameter on the object-side and sensor-side surfaces of the lens. When mathematical expression 25 is satisfied, the optical system can be sized for a thin and compact structure while maintaining optical performance. In the first to third embodiments, mathematical expression 25 can preferably satisfy 1.3 < CA_max / CA_min < 1.8.

[0525] [Mathematical Expression 26]

[0526] 1 < CA_max / ImgH < 2

[0527] In mathematical expression 26, CA_max represents the maximum effective diameter on the object-side and sensor-side surfaces of the lens, and ImgH represents the maximum diagonal length of the image sensor 400. When mathematical expression 26 is satisfied, the optical system can maintain good optical performance and be sized for a thin and compact structure. In the first to third embodiments, mathematical expression 26 can preferably satisfy 1 < CA_max / ImgH < 1.5.

[0528] [Mathematical Expression 27]

[0529] 0.5 < CA_min / ImgH < 1

[0530] In mathematical expression 27, CA_min represents the minimum effective diameter on the object-side and sensor-side surfaces of the lens, and ImgH represents the maximum diagonal length of the image sensor 400. When mathematical expression 27 is satisfied, the optical system can maintain good optical performance and be sized for a thin and compact structure. In the first to third embodiments, mathematical expression 27 can preferably satisfy 0.6 < CA_min / ImgH < 0.8.

[0531] [Mathematical Expression 28]

[0532] 20 < TL_X < 40

[0533] In mathematical expression 28, TL_X is the length of optical systems 1000, 1100, and 1200 in the second direction (X-axis direction). Specifically, TL_X can represent the distance from the end of the prism lens to the image sensor. If mathematical expression 28 is satisfied, the overall size of the optical system can be miniaturized. If the value is less than the lower limit of mathematical expression 28, there are manufacturing difficulties; if the value exceeds the upper limit of mathematical expression 28, there are difficulties in miniaturizing the product. In the first to third embodiments, mathematical expression 28 can preferably satisfy 30 < TL_X < 40.

[0534] [Mathematical Expression 29]

[0535]

[0536] In mathematical expression 29, Z can represent Sag, which is the distance from any position on the aspherical surface to the vertex of the aspherical surface along the optical axis. Y can represent the distance from any position on the aspherical surface to the optical axis in the direction perpendicular to the optical axis. c can represent the curvature of the lens, and K can represent the quadratic constant. Additionally, A, B, C, D, E, and F can represent aspherical constants.

[0537] Table 10 shows the resulting values ​​of the mathematical expressions 1 to 29 in the optical systems 1000, 1100, and 1200 of the first to third embodiments. Referring to Table 10, it can be seen that the optical systems 1000, 1100, and 1200 of the first to third embodiments satisfy at least one, two or more, or three or more of the mathematical expressions 1 to 29. In detail, it can be seen that the optical systems 1000, 1100, and 1200 according to the first to third embodiments satisfy all mathematical expressions 1 to 29. Therefore, the optical systems 1000, 1100, and 1200 can have good optical performance at the center and periphery of the field of view (FOV) and can have excellent optical characteristics.

[0538] [Table 10]

[0539] Figure 23 This is an example of a mobile terminal with an optical system according to this embodiment. Figure 5 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 the surface-emitting laser element and light-receiving unit disclosed above as a light-emitting layer. The flash module 1530 may include an emitter that emits light therein. The flash module 1530 can be operated via the camera operation of the mobile terminal or by user control. The camera module 1520 may include image capture functionality and autofocus functionality. For example, the camera module 1520 may include an autofocus function for using images.

[0540] 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 of the image from the camera module 1520 is degraded. Additionally, although not shown in the figures, at least one camera module may be further arranged in front of the mobile terminal 1500. At least one of the camera modules in the mobile terminal may have the telephoto-type folding optical system disclosed above.

[0541] Optical systems or camera modules according to embodiments of the present invention, and lens assemblies according to various embodiments, can be applied to electronic devices, for example, those employing image sensors. Lens assemblies according to exemplary embodiments can be applied to various electronic devices, such as digital cameras, interchangeable lens cameras, video cameras, mobile phone cameras, cameras for small mobile devices, VR, AR, drones, or manned / unmanned aerial vehicles.

[0542] The features, structures, effects, etc., described in the above embodiments are included in at least one embodiment and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc., shown in each embodiment can be combined or modified by those skilled in the art to which that embodiment pertains and implemented in other embodiments. Therefore, content related to such combinations and modifications should be interpreted as being included within the scope of the embodiments.

[0543] Furthermore, although the embodiments have been described above, these are merely examples and do not limit the invention. Those skilled in the art will recognize that various modifications and applications not illustrated above can be made without departing from the essential characteristics of the invention. For example, each component specifically shown in the examples can be modified and implemented. Moreover, differences related to these modifications and applications should be interpreted as being included within the scope of the invention as defined by the appended claims.

Claims

1. An optical system, comprising: The first to fifth lens groups are arranged along the optical axis. The first lens group has positive (+) refractive power. The second lens group has negative (-) refractive power. The third lens group has positive (+) refractive power. The fourth lens group has negative (-) refractive power. The fifth lens group has positive (+) refractive power. The first lens group includes a prism lens. Wherein, the first lens group and the second lens group are fixed groups, and The third lens group, the fourth lens group, and the fifth lens group are movable groups.

2. The optical system according to claim 1, in, The travel length of the third lens group is greater than that of the fourth lens group.

3. The optical system according to claim 1, in, In the fifth lens group, the lens closest to the sensor has a biconvex shape on the optical axis.

4. The optical system according to claim 1, in, In the first lens group, the lens positioned closest to the object side has a meniscus shape that bulges toward the object side on the optical axis.

5. The optical system according to claim 1, in, The first lens group includes a first lens having positive (+) refractive power and a second lens serving as a prism lens, and The second lens group includes a third lens with negative (-) refractive power and a fourth lens with negative (-) refractive power.

6. The optical system according to claim 1, in, The third lens group includes a fifth lens with positive (+) refractive power and a sixth lens with negative (-) refractive power. The fourth lens group includes a seventh lens with positive (+) refractive power and an eighth lens with negative (-) refractive power, and The fifth lens group includes a ninth lens with positive (+) refractive power.

7. The optical system according to claim 1, in, Each of the second to fourth lens groups includes two lenses with different refractive powers.

8. The optical system according to claim 6, in, Among the first to ninth lenses, the first lens has the largest effective diameter.

9. The optical system according to claim 1, satisfying the following conditional expression, <conditional expression> 0.1 < TD_LG2 / TD_LG3 < 0.5 in, In the above <conditional expression>, TD_LG2 is the length of the second lens group in the optical axis direction, and TD_LG3 is the length of the third lens group in the optical axis direction.

10. The optical system according to claim 1, satisfying the following conditional expression, <conditional expression> 15 < F1 < 65 in, In the above <conditional expression>, F1 is the focal length of the first lens.

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