Optical system and camera module

Abstract

An optical system disclosed in an embodiment of the present invention comprises first to ninth lenses aligned along an optical axis from an object toward an image sensor, wherein: the first lens has positive refractive power; the ninth lens closest to the image sensor has different focal lengths in a first direction and a second direction that are orthogonal to each other with respect to the optical axis; and the ninth lens moves along the optical axis, and can correct the difference, caused by the first to eighth lenses, between focal lengths in the first and second directions.

Description

Optical system and camera module

[0001] The embodiment relates to an optical system for enhanced optical performance and a camera module including the same.

[0002] Camera modules perform the function of capturing objects and saving them as images or videos, and are installed in various applications. In particular, camera modules are manufactured to be ultra-compact, allowing them to be applied not only to portable devices such as smartphones, tablet PCs, and laptops, but also to drones and vehicles, providing a variety of functions. 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 aligns the focal length of the lens by automatically adjusting the distance between the image sensor and the imaging lens, and can perform a zooming function of zooming up or zooming out to increase or decrease the magnification of distant objects through a zoom lens. Additionally, the camera module employs image stabilization (IS) technology to correct or prevent image shaking caused by camera movement resulting from unstable mounting devices or user movements.

[0003] The most important element for a camera module to obtain an image is the imaging lens that forms the image. Recently, interest in high resolution has been increasing, and research on optical systems containing multiple lenses is being conducted to achieve this. For example, research is being conducted using multiple imaging lenses with positive (+) or negative (-) refractive power to achieve high resolution. However, when multiple lenses are included, there is a problem in that it is difficult to derive excellent optical characteristics and aberration characteristics. In addition, when multiple lenses are included, the overall length and height may increase due to the thickness, spacing, and size of the multiple lenses, which leads to a problem in that the overall size of the module containing the multiple lenses increases.

[0004] The size of image sensors is increasing to realize high-resolution and high-quality images. However, as the size of the image sensor increases, the TTL of the optical system containing multiple lenses also increases, which leads to the problem of increased thickness in cameras, mobile terminals, etc., containing the said optical system.

[0005] When the above optical system includes multiple lenses, zoom and autofocus (AF) functions can be performed by controlling the position of at least one lens or a lens group including at least one lens. However, when the lens or the lens group performs the above functions, the amount of movement of the lens or the lens group may increase exponentially. Accordingly, the optical system may require a large amount of energy for the movement of the lens or the lens group, and there is a problem that a large volume is required to account for the amount of movement. In addition, there is a problem that aberration characteristics deteriorate due to the movement of the lens or the lens group. Consequently, there is a problem that optical characteristics deteriorate at a specific magnification when performing zoom or AF functions. Therefore, a new optical system capable of solving the aforementioned problems is required.

[0006] The embodiment aims to provide an optical system with improved optical characteristics. The embodiment aims to provide an optical system and camera module having a lens capable of compensating for imbalances in two directions orthogonal to the optical axis depending on temperature or injection conditions. The embodiment aims to provide an optical system and camera module having a lens having a lens surface symmetrical in a first direction orthogonal to the optical axis or a lens surface symmetrical in a second direction. The embodiment aims to provide an optical system and camera module in which the lens closest to the image sensor has cylindrical power. The embodiment aims to provide an optical system and camera module that can be implemented in a small and compact manner.

[0007] An optical system according to an embodiment of the invention includes first to ninth lenses aligned with an optical axis from an object toward an image sensor, wherein the first lens has a positive refractive power, and the ninth lens closest to the image sensor has different focal lengths in a first direction and a second direction that are orthogonal to each other with respect to the optical axis, and the ninth lens can move along the optical axis and correct the difference in focal lengths in the first and second directions caused by the first to eighth lenses.

[0008] According to an embodiment of the invention, the ninth lens may have a cylinder power. The object-side surface of the ninth lens may have an asymmetrical shape with respect to the optical axis in the first direction and the second direction. The sensor-side surface of the ninth lens may have an asymmetrical shape with respect to the optical axis in the first direction and the second direction. The absolute value of the radius of curvature of the object-side surface of the ninth lens may differ from each other in the first direction and the second direction with respect to the optical axis, and the absolute value of the radius of curvature of the sensor-side surface of the ninth lens may differ from each other in the first direction and the second direction with respect to the optical axis. The object-side surface and the sensor-side surface of the ninth lens may have a flat shape in either the first or second direction with respect to the optical axis.

[0009] According to an embodiment of the invention, the absolute value of the radius of curvature in the first direction of the object-side surface of the ninth lens may be smaller than the absolute value of the radius of curvature in the first direction of the sensor-side surface. The absolute value of the radius of curvature in the second direction of the object-side surface of the ninth lens may be smaller than the absolute value of the radius of curvature in the second direction of the sensor-side surface. The ninth lens has a center thickness smaller than the center thickness of the first lens, and the effective length of the ninth lens may be smaller than the effective length of the first lens.

[0010] According to an embodiment of the invention, the object-side surface of the first lens may have a convex shape on the optical axis. The first to eighth lenses may be made of plastic, and the ninth lens may be made of glass.

[0011] According to an embodiment of the invention, the optical axis distance from the center of the object-side surface of the first lens to the top surface of the image sensor is TTL, and the focal length in the first direction of the optical system is Fx, satisfying the formula: 0 < TTL / Fx < 1. The focal length in the second direction of the optical system is different from the focal length in the first direction and is denoted as Fy, satisfying the formula: 0 < TTL / Fy < 1.

[0012] The optical system and camera module according to the embodiment can provide the lens closest to the image sensor with an asymmetric shape with respect to first and second directions orthogonal to the optical axis. Accordingly, in an optical system having an effective focal length longer than TTL, the imbalance of optical aberration characteristics in the first and second directions can be suppressed. Additionally, by moving the asymmetric lens closest to the image sensor along the optical axis, the imbalance of optical aberration characteristics in the first and second directions can be suppressed.

[0013] The optical system and camera module according to the embodiment have various magnifications and can possess excellent optical characteristics when providing various magnifications. Specifically, the embodiment can have various magnifications by controlling the movement distance of each of the movable lens groups and can provide an autofocus (AF) function for a subject. The optical system and camera module according to the embodiment can correct aberration characteristics of multiple lens groups or mutually complement aberration characteristics that change due to movement. Accordingly, the optical system according to the embodiment can minimize or prevent changes in chromatic aberration and aberration characteristics that occur when the magnification changes.

[0014] The optical system and camera module according to the embodiment control the effective focal length (EFL) by moving only some of the lens groups among a plurality of lens groups, and can minimize the movement distance of the moving lens groups. Accordingly, the optical system can reduce the movement distance of the lens groups moving according to the change in operating mode and minimize power consumption required when moving the lens groups. In addition, at least one lens included in the fixed group and the moving group of the optical system may have a non-circular shape.

[0015] The optical system according to an embodiment of the invention reflects incident light using a prism, thereby allowing the thickness of the optical system to be reduced while maintaining optical performance, and the overall length of the optical system to be shortened. Additionally, the camera module of a mobile terminal can be miniaturized. The optical system and camera module according to the embodiment can adjust the magnification by moving a lens group other than the first lens group adjacent to the subject among a plurality of lens groups. Accordingly, the optical system can maintain a constant TTL value even when the lens group is moved in accordance with the change in magnification. Therefore, the camera module can be provided with a slimmer structure having a folded zoom optical system.

[0016] FIG. 1 is a configuration diagram showing an example of a camera module and an optical system according to an embodiment of the invention.

[0017] Figures 2a (a)-(d) are examples of side cross-sections, side views, and perspective views according to the first and second directions of the last lens of the optical system of Figure 1.

[0018] FIG. 2b is a diagram showing examples of the focal positions in the first and second directions of the last lens of FIG. 1.

[0019] Figure 2c (a)(b) is a diagram illustrating the focal position of the last lens in the first and second directions.

[0020] Figure 3 is a first example of lens data for the camera module and optical system of Figure 1.

[0021] Figure 4 is a second example of lens data for the camera module and optical system of Figure 1.

[0022] Figure 5 is a third example of lens data for the camera module and optical system of Figure 1.

[0023] Figure 6 is a fourth example of lens data for the camera module and optical system of Figure 1.

[0024] Figure 7 is a fifth example of lens data for the camera module and optical system of Figure 1.

[0025] Figure 8 is the sixth example of lens data for the camera module and optical system of Figure 1.

[0026] Figure 9 is the seventh example of lens data for the camera module and optical system of Figure 1.

[0027] FIG. 10 is the eighth example of lens data for the camera module and optical system of FIG. 1.

[0028] FIG. 11 is the ninth example of lens data for the camera module and optical system of FIG. 1.

[0029] FIG. 12 is the 10th example of lens data for the camera module and optical system of FIG. 1.

[0030] FIG. 13 is a graph comparing correction data according to the amount of movement of the last lens in examples of camera modules and optical systems of FIG. 3 to 12.

[0031] Figure 14 is another example of the optical system and camera module of Figure 1.

[0032] FIG. 15 is a drawing showing an example of a portable device having an optical system and a camera module according to an embodiment of the invention.

[0033] FIG. 16 is a perspective view of a mobile terminal having an optical system and a camera module according to an embodiment of the invention.

[0034] FIG. 17 is a plan view showing an example of a moving body having an optical system and a camera module according to an embodiment of the invention.

[0035] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted. Furthermore, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a meaning generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms used generally, such as those defined in advance, may be interpreted by considering their meaning in the context of the relevant technology. The terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention.

[0036] In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as "at least one of A and B and C (or more than one)," it may include one or more of all combinations that can be formed from A, B, and C. Additionally, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the embodiments of the present invention. These terms are intended only to distinguish the component from other components and are not to limit the essence, order, or sequence of the component. Furthermore, when it is stated that a component is 'connected,' 'combined,' or 'connected' to another component, this may include not only cases where the component is directly connected, combined, or connected to the other component, but also cases where it is 'connected,' 'combined,' or 'connected' due to another component located between the component and the other component. Where described in the specification as being formed or placed "above or below" each component, "above or below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Furthermore, when expressed as "above or below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0037] In the specification, the statement that the lens surface is convex may mean that the lens surface in the region corresponding to the optical axis or the paraxial region has a convex shape with respect to the optical axis, and the statement that the lens surface is concave may mean that the lens surface in the region corresponding to the optical axis or the paraxial region has a concave shape. Additionally, "object side surface" may mean the lens surface facing the object side with respect to the optical axis, and "sensor side surface" may mean the lens surface facing the imaging plane (image sensor) with respect to the optical axis. Additionally, the center thickness of the lens may mean the thickness of the lens in the optical axis direction from the optical axis. Additionally, the vertical direction may mean the direction perpendicular to the optical axis, and the end of the lens or lens surface may mean the end of the effective region of the lens through which incident light passes. Additionally, the size of the effective diameter of the lens surface may have a measurement error of up to ±0.4 mm depending on the measurement method, etc. In the following, the units of length, thickness, spacing, radius of curvature, distance, etc. are mm.

[0038]

[0039] As shown in FIG. 1, an optical system (100) and a camera module according to an embodiment of the invention may include a plurality of lens groups. The plurality of lens groups may include at least three lens groups. Each of the plurality of lens groups includes at least one lens, and any one of the plurality of lens groups may have a lens having an asymmetric lens surface. The asymmetric lens surface may have a shape in which the first direction (X, Y) orthogonal to the optical axis (OA) is different. The plurality of lens groups may be aligned with the optical axis (OA). The plurality of lens groups may include a first lens group (LG1) closest to an object, a last lens group closest to an image sensor (190), and one or more lens groups between the first lens group (LG1) and the last lens group. The plurality of lens groups include first to fourth lens groups (LG1-LG4). That is, the optical system (100) may include first to fourth lens groups (LG1-LG4) arranged sequentially along an optical axis (OA) from an object toward an image sensor (190).

[0040] The second lens group (LG2) is positioned between the first lens group (LG1) and the third lens group (LG3), and the third lens group (LG3) may be positioned between the second lens group (LG2) and the fourth lens group (LG4). The first lens group (LG1) may include lenses with fixed positions. At least one or all of the second lens group (LG2) and the third lens group (LG3) are elements that change the zoom magnification, i.e., the focal length, of the optical system, and the fourth lens group (LG4) is an element that adjusts the focal position of the imaging plane. The fourth lens group (LG4) can be moved along the optical axis (OA) and correct aberration characteristics. The fourth lens group (LG4) can perform the role of controlling the Chief Ray Angle (CRA).

[0041]

[0042] The optical system (100) may include n lenses, the nth lens may be the last lens, and the (n-1)th lens may be the lens closest to the last lens. n is an integer greater than or equal to 7, for example, 7 to 12 or 8 to 11. Within the optical system (100), the lenses may be defined as lens parts. Among the plurality of lens groups, at least one lens group may be a fixed lens group with a fixed position, and at least two lens groups may be variable lens groups with a variable position. For example, a first lens group (LG1) adjacent to an object may be a fixed lens group, and a second to fourth lens group (LG4) positioned between the first lens group (LG1) and the image sensor (190) may be a variable lens group. Here, the variable lens group may be moved in the direction of the optical axis (OA) or returned to its original position. The optical system (100) can provide a continuous zoom optical system having a wide mode, a middle mode, and a telescopic mode by means of the above-described variable lens group. The moving distance of the above-described moving lens group can be set to a maximum of 11 mm or less to reduce the power consumption of the driving member. The optical system of FIG. 1 shows the telescopic mode.

[0043] The number of lenses in each of the first lens group (LG1) and the second lens group (LG2) may differ from one another. The number of lenses in the first lens group (LG1) may be greater than the number of lenses in the second lens group (LG2). The number of lenses in each of the first lens group (LG1) and the third lens group (LG3) may be the same. The number of lenses in each of the second lens group (LG2) and the third lens group (LG3) may differ from one another; for example, the number of lenses in the third lens group (LG3) may be greater than the number of lenses in the second lens group (LG2). The number of lenses in each of the third lens group (LG3) and the fourth lens group (LG4) may differ from one another; for example, the number of lenses in the third lens group (LG3) may be greater than the number of lenses in the fourth lens group (LG4). For example, the number of lenses in the fourth lens group (LG4) is two or fewer.

[0044]

[0045] The number of lenses in each of the first lens group (LG1) and the third lens group (LG3) may be two or more, for example, three. The number of lenses in the second lens group (LG2) may be three or fewer, for example, two. The number of lenses in the first lens group (LG1) may be equal to the number of lenses in each of the third lens group (LG3). The number of lenses in the fourth lens group (LG4) may be smaller than the number of lenses in at least one or all of the first to third lens groups (LG1-LG3). By stacking these number of lenses, an optical system for wide mode, middle mode, and tele mode can be provided, and a bright optical system with an F-number in the range of 2.0 to 5.0 can also be provided depending on the operating mode.

[0046] When in zoom magnification or focusing mode, the maximum travel distance of at least one of the second and third lens groups (LG2, LG3) may be 11 mm or less, and may be in the range of 3 mm to 11 mm or in the range of 3 mm to 8 mm. If the maximum travel distance of the second and third lens groups (LG2, LG3) is greater than the above range, the length of the camera module becomes longer, and it may be difficult to secure optical performance. Also, if it is smaller than the above range, the zoom magnification may be reduced. When in zoom magnification or focusing mode, the maximum travel distance of the fourth lens group (LG4) may be 3 mm or less, and may be in the range of 0 mm to 3 mm or in the range of 0 mm to 2 mm. If the maximum travel distance of the fourth lens group (LG4) is greater than the above range, the length of the camera module becomes longer, and it may be difficult to secure optical performance. Also, if it is smaller than the above range, the zoom magnification may be reduced.

[0047]

[0048] At least one or all of the lenses of the first lens group (LG1) may be made of plastic. As another example, the lens closest to the object among the lenses may be made of glass. At least one of the lenses of the first lens group (LG1) may have a refractive index of 1.6 or higher. For example, the second and third lenses (111, 112) closest to the object may have a refractive index of 1.6 or higher and may be made of plastic. The lenses of the first lens group (LG1) are aspherical lenses. If all of these lenses of the first lens group (LG1) are made of plastic, spherical aberration can be corrected and chromatic dispersion can be reduced. In the specification, the refractive index is the refractive index at the d-line (e.g., 5867.6 nm). The first lens (111) closest to the object among the lenses of the first lens group (LG1) may have different effective lengths in the first direction (X) and the second direction (Y). That is, the first lens (111) may have a non-circular shape or a D-cut shape.

[0049] At least one or all of the lenses of the second lens group (LG2) may be made of plastic, for example, plastic. The lenses of the second lens group (LG2) are aspherical lenses. At least one of the lenses of the second lens group (LG2) may have a refractive index of less than 1.6. The refractive index of the third lens (113) may be less than 1.6. At least one or all of the lenses of the third lens group (LG3) may be made of plastic, for example, plastic. The lenses of the third lens group (LG3) are aspherical lenses. At least one of the lenses of the third lens group (LG3) may have a refractive index of less than 1.6. The refractive index of the seventh and eighth lenses (117, 118) may be less than 1.6.

[0050] At least one or all of the lens surfaces of the lenses of the second and third lens groups (LG2, LG3) may have an aspherical shape on the optical axis, thereby reducing distortion in the periphery of the captured image. The lenses having the aspherical shape can prevent spherical aberration within the optical system (100), and since no aberration occurs even when the effective diameter is increased, it is possible to miniaturize and lighten the camera module. The aspherical lenses may be made of glass mold or plastic material.

[0051] The lens of the fourth lens group (LG4) may be the last lens and may be made of glass or plastic. The last lens may be made of an injection-molded material or glass. For example, the refractive index of the last lens may be less than 1.6. The last lens may have a rotationally asymmetric lens surface with respect to the optical axis (OA). That is, the last lens has an object-side surface or a sensor-side surface that has symmetry with respect to the first axis or the second axis with respect to the optical axis (OA) and has a rotationally asymmetric shape. The last lens closest to the image sensor (190) may have free-form lenses on the object-side surface and the sensor-side surface. The last lens may have cylindrical power. The last lens may be a cylindrical lens. The last lens may be a TS (Tangential-Sagittal focal) lens. The TS lens is a lens in which the focal point is formed at two positions in the horizontal (Sagittal) and vertical (Tangential) directions. The above vertical direction is a first direction orthogonal to the optical axis, and the above vertical direction may be a second direction orthogonal to the optical axis.

[0052] Conventional telescopic optical systems have an effective focal length (EFL) that is longer than TTL, and most of these lenses are plastic lenses. Due to the material properties of plastic injection-molded lenses, optical imbalances occur in the first and second directions depending on changes in ambient temperature or injection conditions. This imbalance in the first and second directions indicates that the radii of the first and second directions are optically different, and the positions where the focal point in the first direction and the focal point in the second direction are formed are formed differently on the image plane. Therefore, lens tolerances regarding the imbalance in the first and second directions are managed during the manufacturing process, and wide lenses are managed with tolerances in the range of 0.1㎛ to 0.3㎛. However, for lenses with long effective focal lengths, such as telescopic or zoom lenses, if the tolerance in the first and second directions is in the range of 0.05㎛ to 0.1㎛, a problem may arise where the focal positions in the first and second directions are separated by more than 10㎛. To this end, the invention provides an optical system (100) equipped with a focus compensation lens, wherein the focus compensation lens can compensate for a focus position in a first direction or a second direction to achieve focus in the first and second directions. The focus compensation lens may be positioned between a zoom lens group or a tele lens group of the lens optical system and an optical filter. For example, the focus compensation lens may be the last lens of the optical system.

[0053]

[0054] The first lens group (LG1) includes first to third lenses (111, 112, 113), and the object-side surface of the first lens group (LG1) may have a convex shape on the optical axis, while the sensor-side surface may have a concave shape on the optical axis. The second lens group (LG2) includes fourth to fifth lenses (114, 115), and the object-side surface of the second lens group (LG2) may have a convex shape on the optical axis, while the sensor-side surface may have a concave shape on the optical axis. The third lens group (LG3) includes sixth to eighth lenses (116, 118), and the object-side surface of the third lens group (LG3) may have a concave shape on the optical axis, while the sensor-side surface may have a concave shape on the optical axis. The first lens group (LG1) may have positive or negative power, and may have a negative focal length, for example. The second lens group (LG2) may have positive or negative power, such as a positive focal length. The third lens group (LG3) may have positive or negative power, such as a negative focal length. The first and third lens groups (LG1, LG3) may have positive power. The fourth lens group (LG4) may have positive or negative power, and, for example, the focal lengths in the first direction (X) and the second direction (Y) may be different. Accordingly, the lens optical system can correct optical aberrations and improve image quality by mixing lenses with positive power and lenses with negative power. The power is the reciprocal of the focal length value.

[0055] If the sum of the refractive indices of the lenses in the above optical system (100) is ΣNd and the sum of the Abbe numbers is ΣVd, the following conditions can be satisfied.

[0056] Condition 1: 12 < ΣNd < 20 Condition 2: 350 < ΣVd < 430

[0057] Aberrations can be controlled by adjusting the refractive index and Abbe number of the lenses in the optical system (100). Chromatic dispersion can be reduced by the lens having the maximum Abbe number, and the chromatic dispersion of the incident light can be increased by the lens having a refractive index of 1.6 or higher.

[0058] Each of the lenses of the optical system (100) may include an effective region and an ineffective region. The effective region may be a region through which light incident on each of the lenses passes. That is, the effective region may be defined as an effective region or CA (Clear aperture) where the incident light is refracted to realize optical characteristics. The ineffective region may be placed around the periphery of the effective region. The ineffective region may be a region where effective light is not incident from the plurality of lenses. That is, the ineffective region may be a region unrelated to the optical characteristics. Additionally, the edge of the ineffective region may be a region fixed to a lens barrel (not shown), etc., that accommodates the lens.

[0059]

[0060] In each lens, the surface adjacent to the object side can be defined as the object side surface, and the surface adjacent to the image sensor can be defined as the sensor side surface. The average effective length of the lens can be provided in the range of 4 mm to 7 mm, for example, 7 mm or less. Here, the average effective length may be the average of the effective lengths of the object side surface and the sensor side surface of each lens, or the average of the maximum effective lengths. Within the first lens group (LG1), the maximum effective length of the object side surface (S1) of the first lens (111) may be provided to be greater than the maximum effective length of the sensor side surface (S18) of the last lens (119). Accordingly, the amount of light incident through the first lens (111) can be increased. By controlling the effective diameter size of each lens, the optical system (100) can control the incident light to compensate for the degradation of optical characteristics due to resolution and temperature changes, and can improve chromatic aberration control characteristics. Here, the effective length of each lens is the average of the effective lengths in two different directions.

[0061]

[0062] In the optical system (100), the Total track length (TTL) may be greater than 4 times ImgH, and preferably, may satisfy the conditions 4 < TTL / ImgH < 12 or 5 < TTL / ImgH < 10. The Total track length (TTL) is the distance along the optical axis (OA) from the center of the object-side surface (S1) of the first lens (111) to the surface of the image sensor (190). ImgH is the length from the center of the image sensor (190) to the diagonal end, or half the diagonal length of the image sensor (190). Here, ImgH and TTL may satisfy the following conditions.

[0063] Condition 1: 4 < TTL / ImgH < 12 Condition 2: 20mm < TTL < 38mm

[0064] Condition 3: 2mm < ImgH < 8mm

[0065] Preferably, condition 3: 3mm < ImgH < 4mm can be satisfied.

[0066] In the optical system (100), the effective focal length (F: EFL) can be provided to be greater than 15 mm, thereby providing a folded zoom optical system for a mobile terminal. Accordingly, the optical system (100) can provide a high-resolution and high-magnification zoom optical system. Here, F, ImgH, and TTL may satisfy the following conditions. The effective focal length is the average of the focal length (Fx) in the first direction (X) and the focal length (Fy) in the second direction (Y).

[0067] Condition 1: 20mm < TTL < F Condition 2: ImgH*3 < F < 50mm

[0068] Condition 3: Fx ≠ Fy Condition 4: 15mm < Fx < 50mm

[0069] Condition 5: 17mm < Fy < 52mm

[0070]

[0071] The optical system (100) or camera module may include an image sensor (190). The image sensor (190) may detect light and convert it into an electrical signal. The image sensor (190) may detect light that has passed through the lens group (LG1-LG4) sequentially. The image sensor (190) may include a device capable of detecting incident light, such as a Charge Coupled Device (CCD) or a Complementary Metal Oxide Semiconductor (CMOS). The optical system (100) or camera module may include an optical filter (192). The optical filter (500) may be placed between the fourth lens group (LG4) and the image sensor (190). The optical filter (192) may be placed between the lens closest to the sensor side among the lenses and the image sensor (190). For example, the optical filter (192) may be placed between the last lens and the image sensor (190). A cover glass (not shown) is placed between the optical filter (192) and the image sensor (190) and protects the top of the image sensor (190) and can prevent a decrease in the reliability of the image sensor (190). The cover glass may be removed.

[0072] The optical filter (192) may include an infrared filter or an infrared cut-off filter (IR cut-off). The optical filter (192) may pass light of a set wavelength band and filter light of a different wavelength band. If the optical filter (192) includes an infrared filter, it may block radiant heat emitted from external light from being transmitted to the image sensor (190). Additionally, the optical filter (192) may transmit visible light and reflect infrared light.

[0073] The optical system (100) according to the embodiment may include an aperture (ST). The aperture (ST) may control the amount of light incident on the optical system (100). The aperture (ST) may be positioned around the perimeter between two lenses within the lens. The aperture (ST) may be positioned around the perimeter between the first lens group (LG1) and the second lens group (LG2). The aperture (ST) may be positioned around the perimeter of the object side surface (S7) of the second lens group (LG2). As another example, the aperture (ST) may be positioned around the perimeter of the sensor side surface of the first lens group (LG1), that is, the sensor side surface of the fourth lens (114).

[0074] The aperture (ST) may function as an aperture if the portion coated on the non-effective surface area of ​​at least one of the lenses of the second lens group (LG2) functions as an aperture. Specifically, the perimeter of the sensor side of the third lens (113) or the object side of the fifth lens (115) among the lenses of the optical system (100) may function as an aperture that controls the amount of light. The optical axis distance between the aperture (ST) and the image sensor (190) is SD, and the value of SD may vary depending on the operating mode, such as wide mode, middle mode, or tele mode.

[0075] Since the second and third lens groups (LG2, LG3) are moved, the optical axis distance between the third lens group (LG3) and the image sensor (190) may vary depending on the operation mode, such as wide mode, middle mode, and tele mode. The optical axis distance between the fourth lens group (LG4) and the image sensor (190) is BFL and may vary depending on the movement of the fourth lens group (LG4).

[0076] The camera module described above may have OIS and AF functions. When shaking occurs in the camera module, information regarding the degree of rotation and positional change of the Hall sensors within the camera module can be detected, and correction for the shaking can be performed. Additionally, the camera module can control the movement of the moving lens group by controlling a driving member via a driving signal, detect positional changes, and vary the focal length. Accordingly, when shooting a subject located at infinity or near distance using the camera module, shaking caused by rotation and positional changes can be effectively corrected. The camera module according to the embodiment can effectively correct shaking caused by rotation and shaking caused by positional changes when shooting a subject located at infinity or near distance. Therefore, the camera module may have enhanced optical characteristics.

[0077]

[0078] Hereinafter, reference will be made to FIGS. 1 and FIGS. 12. In FIGS. 1, the first to ninth lenses (111-119) have object-side surfaces (S1, S3, S5, S7, S9, S11, S13, S15, S17) and sensor-side surfaces (S2, S4, S6, S8, S10, S12, S14, S16, S18). In FIGS. 3 to 12, the object-side surface of each lens (Lens 1-9) is defined as S1, and the sensor-side surface is defined as S2. For convenience of explanation, the lens closest to the object is the first lens (111), and the second to ninth lenses (112-119) may be sequentially stacked on the sensor side of the first lens (111). The center thickness of the first to ninth lenses (111-119) can be defined as CT1 to CT9, and the focal length of the first to ninth lenses (111-119) can be defined as F1 to F9. The refractive index of the first to ninth lenses (111-119) can be defined as Nd1 to Nd9. The Abbe number of the first to ninth lenses (111-119) can be defined as Ad1 to Ad9.

[0079] Additionally, the center distance between two adjacent lenses among the first to ninth lenses (111-119) can be defined as CG1-CG8. For example, the center distance between the first and second lenses (111, 112) is CG1, the center distance between adjacent second and third lenses (112, 113) is CG2, and other center distances (CG3-CG8) can also be defined in the same way as above. The optical axis distance between the ninth lens (119) and the image sensor can be defined as BFL (Back focal length). The optical axis distance (BFL) between the ninth lens (119) and the image sensor (190) can provide a space for the optical filter (192) to be installed.

[0080] Additionally, the effective lengths of the object side and sensor side of the first lens (111) can be defined as CAS1 and CAS2, the effective lengths of the object side and sensor side of the second lens (112) can be defined as CAS3 and CAS4, the effective lengths of the object side and sensor side of the third lens (113) can be defined as CAS5 and CAS6, and the effective lengths of the object side and sensor side of the fourth to ninth lenses can be defined as CAS7, CAS8, CAS9, CAS10, CAS11, CAS12, CAS13, CAS14, CAS15, CAS16, and CAS17 and CAS18. Here, the average of the effective lengths of the object side and sensor side of the first to ninth lenses can be defined as CA1-CA9.

[0081]

[0082] As shown in FIGS. 1 and 3, the first lens (111) may have a positive or negative refractive power, for example, a positive refractive power. The first lens (111) may be made of plastic or glass, for example, a plastic material. The first surface (S1) on the object side of the first lens (111) may have a convex shape on the optical axis (OA), and the second surface (S2) on the sensor side may have a concave shape on the optical axis (OA). The effective length of the first or second direction (X,Y) of the first surface (S1) may be the largest among the lens surfaces of the lenses of the optical system (100). Since the effective length of the first surface (S1) is positioned to be larger than the diagonal length of the image sensor (190), the amount of light incident through the first lens (111) can be improved. The first lens (111) may have effective lengths in a first direction (X) and a second direction (Y) that are orthogonal to each other, which may be equal or different. The shape of the object-side or / and sensor-side of the first lens (111), where the effective lengths in the two orthogonal directions are different, may be non-circular. At least one or both of the first surface (S1) and the second surface (S2) of the first lens (111) may be aspherical.

[0083] The second lens (112) may have a positive (+) or negative (-) refractive power on the optical axis (OA), for example, it may have a positive refractive power. The second lens (112) may include a plastic or glass material, for example, it may be a plastic material. The second lens (112) may include an object-side third surface (S3) and a sensor-side fourth surface (S4), and on the optical axis (OA), the third surface (S3) may have a convex shape and the fourth surface (S4) may have a convex shape. Alternatively, the third surface (S3) may have a convex shape and the fourth surface (S4) may have a concave shape. At least one or both of the third surface (S3) and the fourth surface (S4) of the second lens (112) may be aspherical.

[0084] The third lens (113) may have a positive or negative refractive power, for example, it may have a negative refractive power. The third lens (113) may include a plastic or glass material, for example, it may be a plastic material. The third lens (113) may have a refractive index of 1.60 or higher, for example, 1.70 or higher. The third lens (113) may include a fifth surface (S5) on the object side and a sixth surface (S6) on the sensor side. On the optical axis (OA), the fifth surface (S5) may have a concave shape, and the sixth surface (S6) may have a concave shape. The third lens (113) may have a concave shape on both sides. Alternatively, the fifth surface (S5) may have a convex shape, and the sixth surface (S6) may have a concave shape. Alternatively, the fifth surface (S5) may have a convex shape, and the sixth surface (S6) may have a convex shape. At least one or both of the fifth surface (S5) and the sixth surface (S6) of the third lens (113) may be aspherical.

[0085]

[0086] The fourth lens (114) may have a positive or negative refractive power on the optical axis (OA), for example, it may have a negative positive refractive power. The fourth lens (114) may include a plastic or glass material, for example, a plastic material. The fourth lens (114) includes a seventh surface (S7) on the object side and an eighth surface (S8) on the sensor side, and on the optical axis (OA), the seventh surface (S7) may have a convex shape and the eighth surface (S8) may have a convex shape. Alternatively, the seventh surface (S7) may be concave and the eighth surface (S8) may be concave. Alternatively, the fourth lens may have a meniscus shape that is convex toward the sensor. At least one or both of the seventh surface (S7) and the eighth surface (S8) of the fourth lens (114) may be aspherical.

[0087] The fifth lens (115) may have a positive (+) or negative (-) refractive power on the optical axis (OA), for example, it may have a negative refractive power. The fifth lens (115) may have power on the optical axis (OA) with the same sign as the power sign of the third lens (113). The fifth lens (115) may include a plastic or glass material, for example, it may be a plastic material. The fifth lens (115) may include an object-side ninth surface (S9) and a sensor-side tenth surface (S10), and on the optical axis (OA), the ninth surface (S9) may have a concave shape and the tenth surface (S10) may have a convex shape. That is, the fifth lens (115) may have a meniscus shape that is convex toward the object on the optical axis (OA). Alternatively, the fifth lens (115) may have a shape that is convex on both sides. Alternatively, the fifth lens (115) may have a shape that is concave on both sides or a meniscus shape that is convex toward an object. At least one or both of the ninth surface (S9) and the tenth surface (S10) of the fifth lens (115) may be aspherical.

[0088] The sixth lens (116) may have a positive (+) or negative (-) refractive power on the optical axis (OA), for example, it may have a positive refractive power. The sixth lens (116) may include a plastic or glass material, for example, it may be a plastic material. The sixth lens (116) may include an object-side eleventh surface (S11) and a sensor-side twelfth surface (S12). On the optical axis (OA), the eleventh surface (S11) may have a concave shape, and the twelfth surface (S12) may have a convex shape. That is, the sixth lens (116) may have a convex meniscus shape toward the image sensor (190) on the optical axis (OA). Alternatively, the sixth lens (116) may have a convex shape on both sides. Alternatively, the 11th surface (S11) may have a convex shape, and the 12th surface (S12) may have a concave shape. Alternatively, the 11th surface (S11) may have a concave shape, and the 12th surface (S12) may have a concave shape. At least one or both of the 11th surface (S11) and the 12th surface (S12) of the 6th lens (116) may be aspherical.

[0089]

[0090] The seventh lens (117) may have a positive (+) or negative (-) refractive power on the optical axis (OA), and may have a negative refractive power. The refractive power of the seventh lens (117) has a sign opposite to the sign of the refractive power of the sixth lens (116), so that chromatic aberration can be improved. The seventh lens (117) may include a plastic or glass material, for example, a plastic material. The seventh lens (117) may include a 13th surface (S13) on the object side and a 14th surface (S14) on the sensor side. On the optical axis (OA), the 13th surface (S13) may have a concave shape, and the 14th surface (S14) may have a convex shape. That is, the seventh lens (117) may have a meniscus shape that is convex toward the sensor on the optical axis (OA). As another example, the 13th surface (S13) may have a convex shape and the 14th surface (S14) may have a concave shape. Alternatively, the 13th surface (S13) may have a convex shape and the 14th surface (S14) may have a convex shape. Alternatively, the 13th surface (S13) may have a concave shape and the 14th surface (S14) may have a concave shape. At least one or both of the 13th surface (S13) and the 14th surface (S12) of the 7th lens (117) may be aspherical.

[0091] The eighth lens (118) may have a positive or negative refractive power on the optical axis (OA), for example, it may have a negative refractive power. The eighth lens (118) may include a plastic or glass material, for example, it may be a plastic material. The eighth lens (118) may include a 15th surface (S15) on the object side and a 16th surface (S16) on the sensor side. On the optical axis (OA), the 15th surface (S15) may have a convex shape, and the 16th surface (S16) may have a concave shape. That is, the eighth lens (118) may have a meniscus shape that is convex toward the object. Alternatively, the 15th surface (S15) may have a concave shape, and the 16th surface (S16) may have a convex shape. Alternatively, the 15th surface (S15) may have a convex shape, and the 16th surface (S16) may have a convex shape. At least one or both of the 15th surface (S15) and the 16th surface (S16) of the 8th lens (118) may be aspherical.

[0092] The ninth lens (119) may have a positive or negative refractive power on the optical axis (OA), for example, it may have a positive refractive power. The ninth lens (119) may include a plastic or glass material, for example, it may be a glass material. The ninth lens (119) may include an object-side 17th surface (S17) and a sensor-side 18th surface (S18). On the first direction (X) relative to the optical axis (OA), the 17th surface (S17) may have a convex shape, and the 18th surface (S18) may have a convex shape in the first direction (X). On the second direction (Y) relative to the optical axis (OA), the 17th surface (S17) may have a flat shape, and the 18th surface (S18) may have a flat shape in the second direction (Y). At least one or all of the 17th surface (S17) and the 18th surface (S18) of the 9th lens (119) may be aspherical or free-form surfaces.

[0093]

[0094] The second and third lenses (112, 113) can correct aberrations by having refractive powers of opposite signs (+, -), and the fourth and fifth lenses (114, 115) can correct aberrations by having refractive powers of opposite signs (+, -). The sixth and seventh lenses (116, 117) can correct aberrations by having refractive powers of opposite signs (+, -).

[0095] The center thickness (CT1) of the first lens (111) may be thicker than the edge thickness and thicker than the thickness of the third lens (113). The center thickness (CT4) of the fourth lens (114) may be thicker than the edge thickness and may be the thickest among the thicknesses of the lenses. The center thickness (CT6) of the sixth lens (116) may be the thickest among the center thicknesses of the lenses. The center thickness (CT3) of the third lens (113) may be 1 mm or less or the second thinnest among the center thicknesses of the lenses. The center thickness (CT9) of the ninth lens (119) may be the thinnest among the center thicknesses of the lenses.

[0096] The Abbe number (Ad4) of the fourth lens (114) may be greater than the Abbe numbers of the first to third lenses (111-113). The Abbe number of the fourth lens (114) may be the largest among the Abbe numbers of the lenses. The difference in Abbe numbers between the fourth and fifth lenses (114, 115) may be greater than 20. Accordingly, the second lens group (LG2) can minimize changes in chromatic aberration caused by positions that change according to changes in the operating mode. The Abbe number (Ad4) of the fourth lens (114) may be greater than the Abbe number (Ad6) of the sixth lens (116) by 20, for example, 30 or more. The Abbe number (Ad7) of the seventh lens (117) may be greater than the Abbe number (Ad6) of the sixth lens (116) by 20. The sixth lens (116) and the seventh lens (117) have refractive powers of opposite signs, and can control chromatic aberration when the difference in Abbe numbers is large. Accordingly, the third lens group (LG3) can perform an achromatic function while minimizing changes in chromatic aberration caused by the position changing according to the mode change.

[0097]

[0098] The center thickness (CT4) of the fourth lens (114) may be the thickest among the center thicknesses of the lenses. The center thicknesses (CT1-CT9) of the first to ninth lenses (111-119) may satisfy the following conditions.

[0099] Condition 1: CT3 < CT1 < CT4 Condition 2: CT7 < CT6 < CT4

[0100] Condition 3: CT9 < CT7 < CT2 Condition 4: CT9*3 < CT4 < CT9*8

[0101] The effective length of the first lens (112) may be the largest, and the effective length of the fifth lens (115) may be the smallest. Here, the effective length is the average of the object-side and sensor-side of each lens. In the first lens (111), the radius of curvature of the second surface (S2) may be larger than the radius of curvature of the first surface (S1), for example, it may be more than twice as large. In the eighth lens (118), the radius of curvature of the 15th surface (S15) may be larger than the radius of curvature of the 16th surface (S16), for example, it may be more than four times larger. The radius of curvature of the 10th surface (S10) of the fifth lens (115) may be the largest among the absolute values ​​of the radii of curvature of the first to 16th surfaces (S1-S16). The radius of curvature of the seventh surface (S7) of the fourth lens (114) may be the smallest among the absolute values ​​of the radii of curvature of the first to sixteenth surfaces (S1-S16). Since an aperture (ST) is placed on the seventh surface (S7), the path of light incident on the fourth lens (114) can be controlled.

[0102]

[0103] At least one or all of the second, third, and fourth lens groups (LG2, LG3, LG4) may be moved toward the object or sensor side along the optical axis (OA). The camera module may include a driving member (not shown). The driving member includes a first driving member (not shown) disposed outside the second lens group (LG2), a second driving member (not shown) disposed outside the second lens group (LG2), and a third driving member (not shown) disposed outside the fourth lens group (LG4), and may move the second to fourth lens groups (LG2-LG4) respectively in the direction of the optical axis (OA) according to an operation mode. The operation mode may include a first mode for moving to capture at a first magnification and a third mode for moving to capture at a second magnification higher than the first magnification. Additionally, the operation mode may include a second mode having a magnification between the first and third modes. Here, the first magnification may be the lowest magnification of the optical system (100), and the second magnification may be the highest magnification of the optical system (100). The first mode may be a wide mode, the second mode may be a middle mode, and the third mode may be a tele mode.

[0104] The initial operation mode of the camera module may be any one of the first, second, and third modes, for example, the second mode or the middle mode. For example, in the first mode, each of the second to fourth lens groups (LG2, LG4) may be located at a position defined as the first position (Position 1). In the second mode, each of the second and third lens groups (LG2, LG3) may be located at a position defined as the second position (Position 2), which is closer to the object or the first lens (111) than the first position, and the second lens group (LG2) may be located in a direction closer to the sensor than the first position. In the third mode, each of the second and third lens groups (LG2, LG3) may be located at a position defined as the third position (Position 3), which is closer to the object or the first lens (111) than the second position. Depending on the operating mode, the F number of the optical system (100) provides a brightness of 2.0 or higher, and the F number may be in the range of 2.0 to 5.0.

[0105] The center spacing (CG3) between the first and second lens groups (LG1, LG2), the center spacing (CG5) between the second and third lens groups (LG2, LG3), and the center spacing (CG8) between the third and fourth lens groups (LG3, LG4) can be varied according to the operating mode. Accordingly, the optical system (100) can control the effective focal length and magnification of the optical system (100) by controlling the position of some lens groups according to the operating mode. Since the ninth lens (119) is moved to a different position (119') along the optical axis direction, the center spacing (BFL) between the ninth lens (119) and the image sensor (190) can be varied for focus correction in the first and second directions (X, Y).

[0106]

[0107] As shown in (a) of FIG. 2a, in the side cross-section of the second direction (Y) orthogonal to the optical axis, the object side surface (S17) and the sensor side surface (S18) of the last lens (119) are provided with a flat shape. As shown in (b) of FIG. 2a, in the side cross-section of the first direction (X) orthogonal to the optical axis, the object side surface (S17) and the sensor side surface (S18) of the last lens (119) may have different radii of curvature, for example, the object side surface (S17) is provided with a convex shape and the sensor side surface (S18) is provided with a convex shape. As shown in (c) and (d) of FIG. 2a, the object side surface (S17) of the last lens (119) has different shapes in the first and second directions orthogonal to the optical axis, and the sensor side surface (S18) has different shapes in the first and second directions orthogonal to the optical axis. For example, the object side surface (S17) has a free curved surface in the first direction (X) with respect to the optical axis and has a flat shape in the second direction (Y), and the sensor side surface (S18) has a free curved surface in the first direction (X) with respect to the optical axis and has a flat shape in the second direction (Y). The lens surfaces (S17, S18) of the last lens (119) have a symmetrical shape in the first or second direction (X, Y) with respect to the optical axis, and may have an asymmetrical shape in the first and second directions (X, Y). Accordingly, the focal length in the first direction (X) and the focal length in the second direction (Y) of the last lens (119) are different.

[0108] As in another example, the object side surface (S17) has a flat surface in the first direction (X) with respect to the optical axis and a free surface in the second direction (Y), and the sensor side surface (S18) has a flat surface in the first direction (X) with respect to the optical axis and a free surface in the second direction (Y). As in another example, the object side surface (S17) has a free surface in the first direction (X) with respect to the optical axis and a flat surface in the second direction (Y), and the sensor side surface (S18) has a flat surface in the first direction (X) with respect to the optical axis and a free surface in the second direction (Y). As in other examples, the object side surface (S17) has a flat surface in the first direction (X) with respect to the optical axis and a free surface in the second direction (Y), and the sensor side surface (S18) has a free surface in the first direction (X) with respect to the optical axis and a flat surface in the second direction (Y).

[0109]

[0110] As shown in FIG. 2b, the direction of a ray passing through the last lens (119), which has an asymmetric lens surface with respect to the optical axis, is divided into a first direction (X), for example, the direction of a ray passing through the cross-section in a tangential plane or a vertical direction, and a second direction (Y), for example, the direction of a ray passing through the cross-section in a sagittal plane or a horizontal direction. The focal position (P1) of the ray passing in the tangential plane and the focal position (P2) of the ray passing in the sagittal plane are separated by a predetermined distance (TS: tangential-sagittal focal positions). That is, the focal position (P1) of the ray passing in the tangential plane is focused on the object side rather than the position (P2) of the ray passing in the sagittal plane. Accordingly, the last lens (119) may have a rotationally asymmetric shape on the object side surface with respect to the first or second direction, and a rotationally asymmetric shape on the sensor side surface.

[0111] Since the focal lengths in the first and second directions of the last lens (119) are provided differently, the difference in focal lengths in the first and second directions of the lenses (111-118) placed between the last lens (119) and the object can be corrected by the last lens (119) and focused on the image sensor (190). That is, the lens surfaces of the object-side lenses (111-118) may have different radii of curvature in the first and second directions during the manufacturing process, and the difference in the radii of curvature of these lens surfaces results in different focal lengths in the first and second directions. The invention compensates for the difference in focal length caused by the lenses (111-118) placed on the object side rather than the last lens (119) by making the lens surfaces of the last lens (119) have different radii of curvature for the first and second directions. Accordingly, the lens optical system can reduce the difference in resolution in the first and second directions with respect to the optical axis.

[0112]

[0113] FIGS. 3 to 12 are examples of lens data having the optical system of FIG. 1 according to an embodiment, and represent examples showing the values ​​of Example 1 to Example 10. In FIGS. 3 to 12, the lenses are defined as Lens 1 to Lens 9, and represent the radius of curvature in the X and Y directions of each lens (X-Radius, Y-Radius of curvature), the thickness of each lens along the optical axis (CT), the distance between adjacent lenses along the optical axis (CG), the effective length of the object side and sensor side (S1, S2) of each lens (CA), the Abbe number (Ad), the refractive index (Nd), and the effective focal lengths in the first and second directions of each lens (Fx, Fy). As shown in FIGS. 1 and 3, the nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different focal lengths in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the focal lengths of the first and second directions (X,Y) of the ninth lens (119) are F9x and F9y, and may be different from each other. At least one or all of the following conditions may be satisfied. Fx is the effective focal length of the first direction of the optical system.

[0114] Condition 1: F9x ≠ F9y Condition 2: F9x < F9y

[0115] Condition 3: 100 mm < F9x < 600 mm Condition 4: 3 < F9x / Fx < 23

[0116] The nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different radii of curvature in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the radii of curvature in the first and second directions (X,Y) of the object-side surface (S17) of the ninth lens (119) may be Rx17 and Ry17 and may be different from each other. The radii of curvature in the first and second directions (X,Y) of the sensor-side surface (S18) of the ninth lens (119) may be Rx18 and Ry18 and may be different from each other. The ninth lens (119) may satisfy at least one or all of the following conditions.

[0117] Condition 1: Rx17 ≠ Ry17 Condition 2: |Rx17| < Ry17

[0118] Condition 3: Rx18 ≠ Ry18 Condition 4: |Rx18| < Ry18

[0119] Condition 5: Rx17 < |Rx18| (where Rx18 < 0)

[0120] Condition 6: Ry17 = Ry18 Condition 7: 1 < |Rx18| / Rx17 < 5

[0121] Condition 8: 100 mm < Rx17 < |Rx18| < 800 mm

[0122]

[0123] FIGS. 4 to 12 below are other examples of lens data having the optical system of FIG. 1. As in FIGS. 1 and 4, the nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different focal lengths in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the first and second focal lengths (X,Y) of the ninth lens (119) may be F9x and F9y, and may be different from each other. At least one or all of the following conditions may be satisfied. Fx is the effective focal length in the first direction of the optical system.

[0124] Condition 1: F9x ≠ F9y Condition 2: F9x < F9y

[0125] Condition 3: 300 mm < F9x < 900 mm Condition 4: 15 < F9x / Fx < 35

[0126] The nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different radii of curvature in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the radii of curvature in the first and second directions (X,Y) of the object side surface (S17) of the ninth lens (119) may be Rx17 and Ry17 and may be different from each other. The radii of curvature in the first and second directions (X,Y) of the sensor side surface (S18) of the ninth lens (119) may be Rx18 and Ry18 and may be different from each other. The radii of curvature of the object side surface and the sensor side surface of the ninth lens (119) may satisfy at least one or all of the following conditions.

[0127] Condition 1: Rx17 ≠ Ry17 Condition 2: |Rx17| < Ry17

[0128] Condition 3: Rx18 ≠ Ry18 Condition 4: Rx18 < Ry18

[0129] Condition 5: Rx17 < Rx18 Condition 6: Ry17 = Ry18

[0130] Condition 7: 1 < Rx18 / Rx17 < 5 Condition 8: 150 mm < Rx17 < Rx18 < 900 mm

[0131]

[0132] As shown in FIGS. 1 and 5, the nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different focal lengths in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the first and second focal lengths (X,Y) of the ninth lens (119) may be F9x and F9y, and may be different from each other. At least one or all of the following conditions may be satisfied. Fx is the effective focal length in the first direction of the optical system.

[0133] Condition 1: F9x ≠ F9y Condition 2: |F9x| < F9y

[0134] Condition 3: 300 mm < |F9x| < 900 mm Condition 4: 15 < |F9x| / Fx < 35

[0135] The nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different radii of curvature in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the radii of curvature in the first and second directions (X,Y) of the object side surface (S17) of the ninth lens (119) may be Rx17 and Ry17 and may be different from each other. The radii of curvature in the first and second directions (X,Y) of the sensor side surface (S18) of the ninth lens (119) may be Rx18 and Ry18 and may be different from each other. The radii of curvature of the object side surface and the sensor side surface of the ninth lens (119) may satisfy at least one or all of the following conditions.

[0136] Condition 1: Rx17 ≠ Ry17 Condition 2: |Rx17| < Ry17

[0137] Condition 3: Rx18 ≠ Ry18 Condition 4: |Rx18| < Ry18

[0138] Condition 5: |Rx17| < |Rx18| Condition 6: Ry17 = Ry18

[0139] Condition 7: 1 < |Rx18| / |Rx17| < 5

[0140] Condition 8: 150 mm < |Rx17| < |Rx18| < 900 mm

[0141]

[0142] As shown in FIGS. 1 and 6, the nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different focal lengths in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the first and second focal lengths (X,Y) of the ninth lens (119) may be F9x and F9y, and may be different from each other. At least one or all of the following conditions may be satisfied. Fx is the effective focal length in the first direction of the optical system.

[0143] Condition 1: F9x ≠ F9y Condition 2: |F9x| < F9y

[0144] Condition 3: 100 mm < |F9x| < 600 mm Condition 4: 3 < |F9x| / Fx < 23

[0145] The nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different radii of curvature in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the radii of curvature in the first and second directions (X,Y) of the object side surface (S17) of the ninth lens (119) may be Rx17 and Ry17 and may be different from each other. The radii of curvature in the first and second directions (X,Y) of the sensor side surface (S18) of the ninth lens (119) may be Rx18 and Ry18 and may be different from each other. The radii of curvature of the object side surface and the sensor side surface of the ninth lens (119) may satisfy at least one or all of the following conditions.

[0146] Condition 1: Rx17 ≠ Ry17 Condition 2: |Rx17| < Ry17

[0147] Condition 3: Rx18 ≠ Ry18 Condition 4: Rx18 < Ry18

[0148] Condition 5: 0 < |Rx17| < Rx18 Condition 6: Ry17 = Ry18

[0149] Condition 7: 1 < Rx18 / |Rx17| < 5

[0150] Condition 8: 150 mm < Rx17 < |Rx18| < 900 mm

[0151]

[0152] As shown in FIGS. 1 and 7, the nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different focal lengths in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the first and second focal lengths (X,Y) of the ninth lens (119) may be F9x and F9y, and may be different from each other. At least one or all of the following conditions may be satisfied. Fx is the effective focal length in the second direction of the optical system.

[0153] Condition 1: F9x ≠ F9y Condition 2: |F9y| < F9x

[0154] Condition 3: 100 mm < |F9y| < 600 mm Condition 4: 13 < F9y / Fy < 33

[0155] The nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different radii of curvature in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the radii of curvature in the first and second directions (X,Y) of the object side surface (S17) of the ninth lens (119) may be Rx17 and Ry17 and may be different from each other. The radii of curvature in the first and second directions (X,Y) of the sensor side surface (S18) of the ninth lens (119) may be Rx18 and Ry18 and may be different from each other. The radii of curvature of the object side surface and the sensor side surface of the ninth lens (119) may satisfy at least one or all of the following conditions.

[0156] Condition 1: Rx17 ≠ Ry17 Condition 2: Ry17 < Rx17

[0157] Condition 3: |Ry18| ≠ Ry18 Condition 4: |Ry18| < Rx18

[0158] Condition 5: 0 < Ry17 < |Ry18| Condition 6: Rx17 = Rx18

[0159] Condition 7: 1 < |Ry18| / Ry17 < 5

[0160] Condition 8: 150 mm < Ry17 < |Ry18| < 900 mm

[0161]

[0162] As shown in FIGS. 1 and 8, the nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different focal lengths in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the first and second focal lengths (X,Y) of the ninth lens (119) may be F9x and F9y, and may be different from each other. At least one or all of the following conditions may be satisfied. Fy is the effective focal length in the second direction of the optical system.

[0163] Condition 1: F9x ≠ F9y Condition 2: F9y < F9x

[0164] Condition 3: 300 mm < F9y < 900 mm Condition 4: 15 < F9y / Fy < 35

[0165] The nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different radii of curvature in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the radii of curvature in the first and second directions (X,Y) of the object side surface (S17) of the ninth lens (119) may be Rx17 and Ry17 and may be different from each other. The radii of curvature in the first and second directions (X,Y) of the sensor side surface (S18) of the ninth lens (119) may be Rx18 and Ry18 and may be different from each other. The radii of curvature of the object side surface and the sensor side surface of the ninth lens (119) may satisfy at least one or all of the following conditions.

[0166] Condition 1: Rx17 ≠ Ry17 Condition 2: Ry17 < Rx17

[0167] Condition 3: Rx18 ≠ Ry18 Condition 4: Ry18 < Rx18

[0168] Condition 5: 0 < Ry17 < Ry18 Condition 6: Rx17 = Rx18

[0169] Condition 7: 1 < Ry18 / Ry17 < 5

[0170] Condition 8: 150 mm < Ry17 < Ry18 < 900 mm

[0171]

[0172] As shown in FIGS. 1 and 9, the nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different focal lengths in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the first and second focal lengths (X,Y) of the ninth lens (119) may be F9x and F9y, and may be different from each other. At least one or all of the following conditions may be satisfied. Fy is the effective focal length in the second direction of the optical system.

[0173] Condition 1: F9x ≠ F9y Condition 2: |F9y| < F9x

[0174] Condition 3: 300 mm < |F9y| < 900 mm Condition 4: 15 < |F9y| / Fy < 25

[0175] The nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different radii of curvature in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the radii of curvature in the first and second directions (X,Y) of the object side surface (S17) of the ninth lens (119) may be Rx17 and Ry17 and may be different from each other. The radii of curvature in the first and second directions (X,Y) of the sensor side surface (S18) of the ninth lens (119) may be Rx18 and Ry18 and may be different from each other. The radii of curvature of the object side surface and the sensor side surface of the ninth lens (119) may satisfy at least one or all of the following conditions.

[0176] Condition 1: Rx17 ≠ Ry17 Condition 2: |Ry17| < Rx17

[0177] Condition 3: Rx18 ≠ Ry18 Condition 4: |Ry18| < Rx18

[0178] Condition 5: 0 < |Ry17| < |Ry18| Condition 6: Rx17 = Rx18

[0179] Condition 7: 1 < |Ry18| / |Ry17| < 5

[0180] Condition 8: 150 mm < |Ry17| < |Ry18| < 900 mm

[0181]

[0182] As shown in FIGS. 1 and FIGS. 10, the nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different focal lengths in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the first and second focal lengths (X,Y) of the ninth lens (119) may be F9x and F9y, and may be different from each other. At least one or all of the following conditions may be satisfied. Fy is the effective focal length of the first and second directions of the optical system.

[0183] Condition 1: F9x ≠ F9y Condition 2: |F9y| < F9x

[0184] Condition 3: 100 mm < |F9y| < 600 mm Condition 4: 3 < |F9y| / Fy < 23

[0185] The nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different radii of curvature in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the radii of curvature in the first and second directions (X,Y) of the object side surface (S17) of the ninth lens (119) may be Rx17 and Ry17 and may be different from each other. The radii of curvature in the first and second directions (X,Y) of the sensor side surface (S18) of the ninth lens (119) may be Rx18 and Ry18 and may be different from each other. The radii of curvature of the object side surface and the sensor side surface of the ninth lens (119) may satisfy at least one or all of the following conditions.

[0186] Condition 1: Rx17 ≠ Ry17 Condition 2: |Ry17| < Rx17

[0187] Condition 3: Rx18 ≠ Ry18 Condition 4: Ry18 < Rx18

[0188] Condition 5: 0 < |Ry17| < Ry18 Condition 6: Rx17 = Rx18

[0189] Condition 7: 1 < Ry18 / |Ry17| < 5

[0190] Condition 8: 150 mm < |Ry17| < Ry18 < 900 mm

[0191]

[0192] As shown in FIGS. 1 and 11, the nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different focal lengths in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the first and second focal lengths (X,Y) of the ninth lens (119) may be F9x and F9y and may be different. The first and second focal lengths (X,Y) of the object side surface (S17) of the ninth lens (119) may be F91x and F91y and may be different. The first and second focal lengths (X,Y) of the sensor side surface (S18) of the ninth lens (119) may be F92x and F92y and may be different. At least one or all of the following conditions may be satisfied. Fy and Fy are the effective focal lengths of the first and second directions of the optical system.

[0193] Condition 1: F91x ≠ F91y Condition 2: F92x ≠ F92y

[0194] Condition 3: F91x = F92y Condition 4: |F91y| < F91x

[0195] Condition 5: |F92x| < F92y Condition 6: 0 < |F91y| < |F92x|

[0196] Condition 7: 500 mm < |F92x| < 2000 mm

[0197] Condition 8: 3 < |F91y| / Fy < 23 Condition 9: 30 < |F92x| / Fy < 50

[0198] The nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different radii of curvature in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the radii of curvature in the first and second directions (X,Y) of the object side surface (S17) of the ninth lens (119) may be Rx17 and Ry17 and may be different from each other. The radii of curvature in the first and second directions (X,Y) of the sensor side surface (S18) of the ninth lens (119) may be Rx18 and Ry18 and may be different from each other. The radii of curvature of the object side surface and the sensor side surface of the ninth lens (119) may satisfy at least one or all of the following conditions.

[0199] Condition 1: Rx17 ≠ Ry17 Condition 2: |Ry17| < Rx17

[0200] Condition 3: Rx18 ≠ Ry18 Condition 4: Rx18 < Ry18

[0201] Condition 5: 0 < |Ry17| < Rx18 Condition 6: Rx17 = Ry18

[0202] Condition 7: 1 < Rx18 / |Ry17| < 5

[0203] Condition 8: 150 mm < |Ry17| < Rx18 < 900 mm

[0204]

[0205] As shown in FIGS. 1 and 12, the nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different focal lengths in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the first and second focal lengths (X,Y) of the ninth lens (119) may be F9x and F9y and may be different. The first and second focal lengths (X,Y) of the object side surface (S17) of the ninth lens (119) may be F91x and F91y and may be different. The first and second focal lengths (X,Y) of the sensor side surface (S18) of the ninth lens (119) may be F92x and F92y and may be different. At least one or all of the following conditions may be satisfied. Fy and Fy are the effective focal lengths of the first and second directions of the optical system.

[0206] Condition 1: F91x ≠ F91y Condition 2: F92x ≠ F92y

[0207] Condition 3: F91y = F92x Condition 4: |F91x| < F91y

[0208] Condition 5: |F92y| < F92x Condition 6: 0 < |F91x| < |F92y|

[0209] Condition 7: 500 mm < |F92y| < 2000 mm

[0210] Condition 8: 10 < |F91x| / Fx < 30 Condition 9: 30 < |F92y| / Fy < 50

[0211] The nth lens closest to the image sensor (190), i.e., the ninth lens (119), may have different radii of curvature in the first direction (X) and the second direction (Y) on the optical axis (OA). For example, the radii of curvature in the first and second directions (X,Y) of the object side surface (S17) of the ninth lens (119) may be Rx17 and Ry17 and may be different from each other. The radii of curvature in the first and second directions (X,Y) of the sensor side surface (S18) of the ninth lens (119) may be Rx18 and Ry18 and may be different from each other. The radii of curvature of the object side surface and the sensor side surface of the ninth lens (119) may satisfy at least one or all of the following conditions.

[0212] Condition 1: Rx17 ≠ Ry17 Condition 2: |Rx17| < Ry17

[0213] Condition 3: Rx18 ≠ Ry18 Condition 4: Ry18 < Rx18

[0214] Condition 5: 0 < |Rx17| < Ry18 Condition 6: Ry17 = Rx18

[0215] Condition 7: 1 < Ry18 / |Rx17| < 5

[0216] Condition 8: 150 mm < |Rx17| < Ry18 < 900 mm

[0217]

[0218] Fx, Fy, and TTL of Examples 1 to 10 disclosed above are as shown in Table 1 below, and the unit is mm.

[0219] Item Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 TTL 24.524.524.524.524.524.524.524.524.524.5Fx 28.40428.4428.5628.59728.528.528.528.528.528.52828.569Fy 28.528.528.528.528.40328.4428.5628.59728.56928.528

[0220]

[0221] FIG. 13 and Table 2 show the displacement amount (mm) and focal position correction amount (TS) of the last lens (Ln or L9) according to Examples 1 to 10 (case #1-#10) having the optical system of FIG. 1 and the lens data of FIG. 3 to 12. This focal position correction amount can compensate for the difference in focal position in the horizontal / vertical direction by the lenses placed on the object side of the last lens.

[0222] Ln Displacement (mm) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 0 5.5 4.1 -3.0 -4.4 -4.4 -3.0 3.8 5.3 2.7 -2.1 -0.2 7.1 5.1 -4.0 -5.9 -5.9 -4.0 4.7 6.8 3.3 -2.7 -0.4 8.7 6.2 -5.0 -7.5 -7.6 -5.1 5.88 .43.9-3.4-0.610.57.3-6.2-9.3-9.4-6.26.910.24.6-4.1-0.812.48.6-7.4-11 .2-11.4-7.58.112.15.4-4.8-114.59.9-8.6-13.3-13.6-8.89.514.36.2-5.6TS [um]8.9265.7205.68.99.25.85.79.03.53.5

[0223]

[0224] The camera module according to the embodiment has improved resolution and can have good optical performance in the center and periphery of the field of view (FOV). The lens optical system of the embodiment according to the invention is a combination of an object-side lens having a reflective surface and nine or more lenses, which is compact and lightweight, while simultaneously correcting spherical aberration, astigmatism, distortion, chromatic aberration, and coma aberration well, so that high resolution can be achieved and thus can be embedded in and utilized in the optical device of a camera.

[0225] The optical system (100) according to the embodiment may satisfy at least one or two of the mathematical formulas described below. Accordingly, the optical system (100) according to the embodiment can effectively correct aberrations that change according to the change in operating mode. The optical system (100) can adjust the zoom magnification for a subject at various magnifications and may have a slim and compact structure. Below, the description will be based on the optical system being in tele mode. In addition, the effective length of each lens or each lens surface (object side or sensor side) is indicated as the effective diameter when it is circular, and as the maximum effective length when it is non-circular. The thickness is the optical axis or center thickness, and the units of the spacing, thickness, effective diameter, focal length, etc. are mm.

[0226] [Mathematical Formula 1] Fx ≠ Fy

[0227] In Equation 1, Fx is the focal length in the first direction (X) or vertical direction of the optical system, and Fy is the focal length in the second direction (X) or horizontal direction of the optical system. When Equation 1 is satisfied, the object-side or sensor-side surface of the last lens is provided with an asymmetrical shape in the first and second directions on the optical axis, thereby correcting the difference in focal lengths in the first and second directions. Accordingly, the lenses placed on the object side of the last lens can correct the difference between focal lengths caused by the difference in the first and second directions of the radius of curvature of the object-side or sensor-side surface that occurs during the manufacturing process.

[0228] [Mathematical Equation 2] LnFx ≠ LnFy

[0229] In Equation 2, LnFx is the focal length in the first direction (X) or vertical direction of the last lens of the optical system, and LnFy is the focal length in the second direction (X) or horizontal direction of the last lens of the optical system. When Equation 2 is satisfied, the object side or sensor side of the last lens is provided with different focal lengths in the first and second directions, so the difference in focal lengths in the first and second directions can be corrected.

[0230] [Mathematical Equation 3] LnR1x ≠ LnR1y

[0231] In Equation 3, LnR1x is the radius of curvature in the first direction (X) of the object-side surface of the last lens with respect to the optical axis, and LnR1y is the radius of curvature in the first direction (X) of the object-side surface of the last lens with respect to the optical axis. When Equation 3 is satisfied, the radius of curvature in the first and second directions of the object-side surface of the last lens is provided differently, so the difference in focal lengths in the first and second directions can be corrected.

[0232] [Mathematical Equation 4] LnR2x ≠ LnR2y

[0233] In Equation 4, LnR2x is the radius of curvature in the second direction (Y) of the sensor-side surface of the last lens with respect to the optical axis, and LnR2y is the radius of curvature in the second direction (Y) of the sensor-side surface of the last lens with respect to the optical axis. If Equation 4 is satisfied, the radius of curvature in the first and second directions of the sensor-side surface of the last lens is provided differently, thereby correcting the difference in focal lengths in the first and second directions.

[0234] [Mathematical Equation 5] |LnR1x| < |LnR2x|

[0235] In Equation 5, |LnR1x| is the absolute value of the radius of curvature in the first direction (X) of the object-side surface of the last lens with respect to the optical axis, and |LnR2x| is the absolute value of the radius of curvature in the first direction (X) of the sensor-side surface of the last lens with respect to the optical axis. If Equation 5 is satisfied, the radius of curvature in the first direction of the object-side surface and the sensor-side surface of the last lens are provided differently, thereby correcting the difference in focal lengths between the first and second directions. Equation 5 can satisfy Examples 1 through 4.

[0236] [Mathematical Equation 6] LnR1y = LnR2y

[0237] In Equation 6, LnR1y is the radius of curvature in the second direction (Y) of the object-side surface of the last lens with respect to the optical axis, and LnR2y is the radius of curvature in the second direction (Y) of the sensor-side surface of the last lens with respect to the optical axis. If Equation 6 is satisfied, the object-side surface and the sensor-side surface of the last lens are provided flat in the second direction, thereby correcting the difference in focal length between the first and second directions. Equation 6 can satisfy Examples 1 through 4.

[0238] [Mathematical Equation 7] LnR1x = LnR2x

[0239] In Equation 7, LnR1x is the radius of curvature in the first direction (X) of the object-side surface of the last lens with respect to the optical axis, and LnR2x is the radius of curvature in the first direction (X) of the sensor-side surface of the last lens with respect to the optical axis. If Equation 7 is satisfied, the object-side surface and the sensor-side surface of the last lens are provided flat in the first direction, thereby correcting the difference in focal length between the first and second directions. Equation 7 can satisfy Examples 5 through 8.

[0240] [Mathematical Equation 8] |LnR1y| < |LnR2y|

[0241] In Equation 8, |LnR1y| is the absolute value of the radius of curvature in the second direction (Y) of the object-side surface of the last lens with respect to the optical axis, and |LnR2y| is the absolute value of the radius of curvature in the second direction (Y) of the sensor-side surface of the last lens with respect to the optical axis. If Equation 8 is satisfied, the radius of curvature in the second direction of the object-side surface and the sensor-side surface of the last lens are provided differently, thereby correcting the difference in focal length between the first and second directions. Equation 8 can satisfy Examples 5 through 8.

[0242]

[0243] [Mathematical Equation 9] CTn < CT1

[0244] In Equation 9, CTn is the center thickness of the last lens, and CT1 is the center thickness of the first lens closest to the object. Since Equation 9 is satisfied, the factors affecting aberration improvement can be controlled.

[0245] [Mathematical Formula 10] 0.75mm < BFL

[0246] BFL (Back focal length) is the optical axis distance between the last lens and the image sensor. That is, BFL is the distance between the center of the sensor side of the last lens and the center of the image sensor. If Equation 10 is satisfied, space can be secured to insert components such as optical filters between the last lens and the image sensor.

[0247] [Mathematical Formula 11] Ndn < Nd1

[0248] Ndn is the refractive index of the last lens, and Nd1 is the refractive index of the first lens. If Equation 11 is satisfied, TTL can be adjusted and improved resolution can be provided.

[0249] [Mathematical Formula 12] Ad1 < Adn

[0250] Adn is the Abbe number of the last lens, and Ad1 is the Abbe number of the first lens. If Equation 12 is satisfied, the TTL of the optical system can be adjusted and improved resolution can be provided.

[0251] [Mathematical Formula 13] (Ad1*Nd1) < (Adn*Ndn)

[0252] Equation 13 can set the product of the Abbe number and refractive index of the first lens and the product of the Abbe number and refractive index of the last lens. Accordingly, the TTL of the optical system can be adjusted and improved resolution can be provided.

[0253] [Equation 14] CA(n-1) < CAn < CA1

[0254] Can is the average of the effective lengths of the object side and the sensor side of the last lens, i.e., the n-th lens; CA(n-1) is the average of the effective lengths of the object side and the sensor side of the n-1-th lens; and CA1 is the average of the effective lengths of the object side and the sensor side of the first lens. If Equation 14 is satisfied, the amount of light incident through the first lens can be increased.

[0255] [Mathematical Formula 15] 0 < TTL / Fx < 1

[0256] In Equation 15, TTL is the optical axis distance from the center of the object-side surface of the first lens to the top surface of the image sensor. If Equation 15 is satisfied, the focal length and total length of the first direction of the optical system can be set. Preferably, 0.5 < TTL / Fx < 1 can be satisfied.

[0257] [Mathematical Formula 16] 0 < TTL / Fy < 1

[0258] If mathematical equation 16 is satisfied, the focal length of the second direction and the total length of the optical system can be set. Preferably, 0.5 < TTL / Fy < 1 can be satisfied.

[0259] [Mathematical Formula 16-1] TTL / LnFx ≠ TTL / LnFy

[0260] By providing different focal lengths in the first and second directions of the last lens, it is possible to compensate for the difference in focal lengths in the first and second directions caused by errors in the lens surface during the manufacturing process.

[0261] [Mathematical Formula 17] 0 < L1R1

[0262] L1R1 is the radius of curvature of the object-side surface of the first lens, and can have a shape that is convex toward the object. Accordingly, the amount of light incident through the object-side surface of the first lens can be increased.

[0263] [Mathematical Formula 18] 1 <L1R2 / L1R1 < 10

[0264] L1R2 is the radius of curvature of the sensor side of the first lens, and if mathematical formula 18 is satisfied, the distance between the first and second lenses can be increased.

[0265] [Mathematical Formula 19] 1mm < L(n-1)R2 < 20mm

[0266] L(n-1)R2 is the radius of curvature of the sensor-side surface of the n-1th lens, and if this is satisfied, the n-1th lens can refract light across the entire area of ​​the nth lens.

[0267] [Mathematical Formula 20] 2 < CT_Max / CTn < 10

[0268] CT_Max is the thickest center thickness among the center thicknesses of the lenses in the optical system, and CTn is the center thickness of the last lens. If Equation 20 is satisfied, it is possible to control the TTL of the optical system and provide improved resolution. Preferably, 3 < CT_Max / CTn < 7

[0269] [Equation 21] 4 < TTL / ImgH < 12

[0270] ImgH is half the diagonal length of the image sensor. If mathematical formula 21 is satisfied, the optical system (100) can have a smaller TTL and can be provided slim and compact. Additionally, the height of the optical system (100) can be set. Preferably, it can be in the range of 5 < TTL / ImgH < 11.

[0271]

[0272] As shown in FIG. 14, the optical system may comprise a lens unit (100A) having the lens group of FIG. 1, and a reflective member (200) between the first lens group (LG1) of the lens unit (100A) and an object. The reflective member (200) may reflect incident light to the first lens. Accordingly, the optical system may provide a folded zoom optical system. The lens unit (100A) may include the lenses (111-119) of Examples 1-9 disclosed above.

[0273] Table 3 shows the focal length (Fx) in the first direction (X), the focal length (Fy) in the second direction (Y), and the TTL of Examples 1-10.

[0274] Item Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Fx 28.40428.4428.56028.59728.528.528.528.528.528.52828.569 Fy 28.528.528.528.528.40428.4428.56028.59728.56928.528 TTL 24.5

[0275] Table 4 shows the values ​​of Formulas 1 to 21 and satisfaction or dissatisfaction for Examples 1 to 5, and Table 5 shows the values ​​of Formulas 1 to 21 and satisfaction or dissatisfaction for Examples 6 to 10.

[0276] Formula Example 1 Example 2 Example 3 Example 4 Example 5 1 Fx ≠ Fy satisfied 2 Ln Fx ≠ Ln Fy satisfied 3 Ln R1x ≠ Ln R1y satisfied 4 Ln R2x ≠ Ln R2y satisfied 5 |Ln R1x| < |Ln R2x| satisfied 6 Ln R1y = Ln R2y satisfied 7 Ln R1x = Ln R2x dissatisfied 8 |Ln R1y| < |LnR2y|Dissatisfied 9CTn < CT1 Satisfied 100.75 < BFL Satisfied 11Ndn < Nd1 Satisfied 12Ad1 < Adn Satisfied 13(Ad1*Nd1) < (Adn*Ndn) Satisfied 14CA(n-1) < CAn < CA1 Satisfied 150 < TTL / Fx < 10.8630.8610.8580.8570.860160 < TTL / Fy < 10.8600.8600.8600.8600.863170 < L1R17.048181 <L1R2 / L1R1 < 105.485191 < L(n-1)R2 < 209.816202 < CT_Max / CTn < 105.250214 < TTL / ImgH < 127.970

[0277] Formula Example 6 Example 7 Example 8 Example 9 Example 10 1 Fx ≠ Fy satisfied 2 Ln Fx ≠ Ln Fy satisfied 3 Ln R1x ≠ Ln R1y satisfied 4 Ln R2x ≠ Ln R2y satisfied 5 |Ln R1x| < |Ln R2x| dissatisfied 6 Ln R1y = Ln R2y dissatisfied 7 Ln R1x = Ln R2x satisfied 8 |Ln R1y| < |LnR2y|SatisfiedSatisfiedSatisfiedDissatisfied 9CTn < CT1Satisfied 100.75 < BFLSatisfied 11Ndn < Nd1Satisfied 12Ad1 < AdnSatisfied 13(Ad1*Nd1) < (Adn*Ndn)Satisfied 14CA(n-1) < CAn < CA1Satisfied 150 < TTL / Fx < 10.8600.8600.8600.8590.858160 < TTL / Fy < 10.8610.8580.8570.8580.859170 < L1R17.048181 <L1R2 / L1R1 < 105.485191 < L(n-1)R2 < 209.816202 < CT_Max / CTn < 105.520214 < TTL / ImgH < 127.970

[0278] Referring to FIGS. 15 and 16, the mobile terminal is a portable device that performs various multimedia functions in addition to phone calls, and can be extended beyond the dimension of being primarily held in the hand by the user to become a wearable device that can be worn on the body. Such wearable devices include smart watches, smart glasses, and HMDs (head-mounted displays).

[0279] A wearable device, such as that shown in FIG. 15, can be configured to exchange (or interact with) data with other mobile terminals. A near-field communication module can detect (or recognize) a wearable device capable of communicating in the vicinity of a mobile terminal. Furthermore, if the detected wearable device is a device authenticated to communicate with the mobile terminal, the control unit can transmit at least a portion of the data processed by the mobile terminal to the wearable device through the near-field communication module. Accordingly, the user can utilize the data processed by the mobile terminal through the wearable device. For example, it is possible to perform a phone call through the wearable device when a call is received on the mobile terminal, or to check the received message through the wearable device when a message is received on the mobile terminal.

[0280]

[0281] FIG. 15 is a perspective view illustrating an example of a wearable device having an optical system and a camera module of the invention. A wearable device such as FIG. 15 is composed of a frame (160) and a lens (168) having a shape similar to ordinary glasses, and an optical module (170) equipped with an output unit, an input unit, a sensing unit, etc. is not exposed to the outside as much as possible, thus having a shape similar to ordinary glasses or sunglasses. The frame (160) is composed of a front frame (161) located on the front of the user's face and a side frame (162) including a temple (162b) located on the side of the user's face and hung on the user's ear. The side frame (162) may be composed of a first side frame (162a) fixed to the front frame (161) so as not to change its angle, and a second side frame (162b) that is bent through a hinge or includes a flexible material and hangs on the upper part of the user's ear.

[0282] The front lens (168) is coupled to the frame (160) and is positioned in front of the user's eyes when the user wears the wearable device (100). The present invention configures the frame (160) and the front lens (168) to have a shape similar to ordinary glasses, and mounts an image projection device (151) and a wave guide (153) for providing images to the user on a separate optical module. In addition to the function of providing images, the optical module may also be equipped with various components such as an audio output module, the camera module disclosed above, and a sensor unit.

[0283] The optical module can be configured to be positioned in a direction adjacent to the user when the user wears the wearable device (100), so that another person cannot perceive the optical module (170) from the front. The optical module (170) is configured to be coupled to a wave guide (153) and a frame (160) located at the rear of the front lens (168) (the direction closer to the user when wearing the wearable device is referred to as the rear).

[0284]

[0285] As shown in FIG. 16, this is a drawing illustrating the application to a mobile terminal having an optical system and a camera module according to an embodiment.

[0286] As shown in FIG. 16, a mobile terminal (1000) is a mobile phone and includes an imaging device (1010), and the imaging device (1010) includes at least one camera module (1011, 1012, 1013). For example, one of the camera modules (1011, 1012, 1013) can perform wide-angle shooting, and the other can perform telephoto shooting. The one performing wide-angle shooting may include a camera module having an optical system of the first to fifth embodiments. Although the imaging device (1010) is shown as a rear camera of a smartphone, the imaging device (1010) may be a front camera of a smartphone. In addition, although the mobile terminal (1000) is illustrated as a smartphone, it can be implemented in mobile devices such as PDAs, netbooks, tablet computers, laptop computers, etc., wearable devices such as smartwatches, smart bands, smart glasses, etc., computing devices such as desktops, servers, etc., home appliances such as televisions, smart televisions, refrigerators, etc., security devices such as door locks, CCTVs, etc., vehicles such as autonomous vehicles, smart vehicles, etc., cameras such as VR / AR cameras, 360-degree cameras, drones, etc.

[0287] Additionally, the mobile terminal (1000) may include a flash module (not shown) and an autofocus device (not shown). Here, the autofocus device (not shown) may include a surface-emitting laser element and a light receiver as a light-emitting layer. The flash module may include an emitter that emits light inside. The flash module may be operated by the operation of the camera of the electronic device or by the control of a user. The autofocus device may include an autofocus function using a laser. The autofocus device may be mainly used under conditions where the autofocus function using the image of the camera module is degraded. Additionally, although not shown in the drawings, at least one additional camera module may be disposed on the front of the mobile terminal (1000). At least one of the camera modules within the mobile terminal may have a tele-type folded lens assembly disclosed above.

[0288]

[0289] FIG. 17 is an example of a plan view of a vehicle to which a camera module or optical system according to an embodiment of the invention is applied. Referring to FIG. 17, a vehicle camera system according to an embodiment of the invention includes an image generation unit (11), a first information generation unit (12), a second information generation unit (21, 22, 23, 24, 25, 26), and a control unit (14). The image generation unit (11) may include at least one camera module (31) disposed in the vehicle and may generate a front image of the vehicle or an interior image of the vehicle by photographing the front of the vehicle and / or the driver. The image generation unit (11) may generate an image of the vehicle's surroundings by photographing the vehicle's surroundings in one or more directions as well as the front of the vehicle using the camera module (31). Here, the front image and the surrounding image may be digital images and may include color images, black and white images, and infrared images. Additionally, the front image and the surrounding image may include still images and video images. The image generation unit (11) provides the driver image, the front image, and the surrounding image to the control unit (14). Subsequently, the first information generation unit (12) may include at least one radar or / and camera placed on the vehicle and generates first detection information by detecting the front of the vehicle. Specifically, the first information generation unit (12) is placed on the vehicle and generates first detection information by detecting the position and speed of vehicles located in front of the vehicle, the presence and location of pedestrians, etc.

[0290] By using the first detection information generated by the first information generation unit (12), the distance between the vehicle and the vehicle ahead can be controlled to be maintained at a constant level, and the stability of vehicle operation can be enhanced in specific cases that are pre-set, such as when the driver wants to change the driving lane of the vehicle or when reverse parking. The first information generation unit (12) provides the first detection information to the control unit (14). The second information generation unit (21, 22, 23, 24, 25, 26) generates second detection information by detecting each side of the vehicle based on the front image generated by the image generation unit (11) and the first detection information generated by the first information generation unit (12). Specifically, the second information generation unit (21, 22, 23, 24, 25, 26) may include at least one radar or / and camera placed on the vehicle, and may detect the position and speed of vehicles located on the side of the vehicle or capture images. Here, the second information generating unit (21, 22, 23, 24, 25, 26) can be positioned at the front corners, side mirrors, and rear center and rear corners of the vehicle, respectively.

[0291] At least one information generating unit among such vehicle camera systems may be equipped with an optical system and a camera module having the same as described in the embodiment(s) disclosed above, and can provide or process information obtained through the front, rear, each side, or corner area of ​​the vehicle to a user to protect the vehicle and objects from autonomous driving or surrounding safety. The optical system of the camera module according to the embodiment of the invention may be mounted in multiple units within the vehicle to comply with safety regulations, enhance autonomous driving functions, and increase convenience. Furthermore, the optical system of the camera module is applied within the vehicle as a component for control such as a Lane Keeping Assistance System (LKAS), Lane Departure Warning System (LDWS), and Driver Monitoring System (DMS). Such vehicle camera modules can achieve stable optical performance even with changes in ambient temperature and provide cost-competitive modules, thereby ensuring the reliability of vehicle components.

[0292]

[0293] The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment may be combined or modified and implemented in other embodiments by those skilled in the art to which the embodiments belong. Therefore, details regarding such combinations and modifications should be interpreted as being included within the scope of the present invention. Although the above description has focused on embodiments, this is merely illustrative and does not limit the present invention; those skilled in the art to which the present invention belongs will understand that various modifications and applications not exemplified above are possible within the scope that does not deviate from the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments may be modified and implemented. Furthermore, differences related to such modifications and applications should be interpreted as being included within the scope of the present invention as defined in the appended claims.

Claims

1. Includes first to ninth lenses aligned with an optical axis from an object toward an image sensor, and The first lens above has a positive refractive power, and The ninth lens closest to the image sensor has different focal lengths in the first and second directions that are orthogonal to each other with respect to the optical axis, and An optical system in which the ninth lens moves along the optical axis and corrects the difference in focal lengths in the first and second directions caused by the first to eighth lenses.

2. In Paragraph 1, The above-mentioned ninth lens is an optical system having cylinder power.

3. In Paragraph 1, The object-side surface of the ninth lens is an optical system in which the first direction and the second direction have an asymmetric shape with respect to the optical axis.

4. In Paragraph 1, The sensor side surface of the ninth lens is an optical system in which the first direction and the second direction have an asymmetrical shape with respect to the optical axis.

5. In any one of paragraphs 1 through 4, The absolute value of the radius of curvature of the object-side surface of the ninth lens is different from each other in the first direction and the second direction with respect to the optical axis, and The absolute value of the radius of curvature of the sensor side surface of the ninth lens is different optical systems in the first direction and the second direction with respect to the optical axis.

6. In Paragraph 5, An optical system in which the object-side surface and the sensor-side surface of the ninth lens have a flat shape in either the first or second direction with respect to the optical axis.

7. In Paragraph 6, An optical system in which the absolute value of the radius of curvature in the first direction of the object-side surface of the ninth lens is smaller than the absolute value of the radius of curvature in the first direction of the sensor-side surface.

8. In Paragraph 6, An optical system in which the absolute value of the radius of curvature in the second direction of the object-side surface of the ninth lens is smaller than the absolute value of the radius of curvature in the second direction of the sensor-side surface.

9. In any one of paragraphs 1 through 4, The ninth lens has a center thickness smaller than the center thickness of the first lens, and An optical system in which the effective length of the ninth lens is smaller than the effective length of the first lens.

10. In any one of paragraphs 1 to 4, An optical system in which the object-side surface of the first lens has a convex shape on the optical axis.

11. In any one of paragraphs 1 through 4, The above 1st to 8th lenses are made of plastic material, and The above-mentioned ninth lens is an optical system made of glass.

12. In any one of paragraphs 1 through 4, The optical axis distance from the center of the object-side surface of the first lens to the top surface of the image sensor is TTL, and The focal length of the first direction of the above optical system is Fx, and Mathematical formula: 0 < TTL / Fx < 1 An optical system satisfying .

13. In Paragraph 12, The focal length of the second direction of the above optical system is different from the focal length of the first direction, and is denoted as Fy, Mathematical formula: 0 < TTL / Fy < 1 An optical system satisfying .

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