Optical system and camera module comprising the same

Abstract

An optical system disclosed in an embodiment of the present invention can include a first lens group and a second lens group, the first lens group and the second lens group being consecutively arranged along an optical axis in a direction from an object side to a sensor and each including at least one lens, wherein: a focal length of the first lens group and a focal length of the second lens group have signs opposite to each other, and satisfy -1.5 < f_2 / f_1 < 0 (where f_1 denotes the focal length of the first lens group, and f_2 denotes the focal length of the second lens group); each of the lenses included in the first lens group and the second lens group has an aperture size smaller than a diagonal length of the image sensor; and one of the first lens group and the second lens group is movable in the direction of the optical axis.

Description

Technical Field

[0001] The embodiments relate to an optical system with improved optical performance and a thin structure, and a camera module including the optical system. Background Technology

[0002] Camera module captures objects and stores them as images or videos, and is installed in various applications. In particular, camera modules are manufactured in very small sizes and are used not only in portable devices such as smartphones, tablet PCs, and laptops, but also in drones and vehicles to provide a variety of functions. For example, the optical system of a camera module may include an imaging lens for forming an image, and an image sensor for converting the formed image into an electrical signal. In this case, the camera module can perform autofocus (AF) by automatically adjusting the distance between the image sensor and the imaging lens to align the focal length of the lens, and can perform zoom functions by increasing or decreasing the magnification of distant objects via a zoom lens. Furthermore, the camera module employs image stabilization (IS) technology to correct or prevent image jitter caused by unstable fixed equipment or camera movement due to user movement. The most important element for this camera module to acquire images is the imaging lens that forms the image. Recently, there has been increasing interest in high performance, such as high image quality and high resolution, and optical systems including multiple lenses are being researched to achieve such high performance. For example, research is underway to achieve high-performance optical systems using multiple imaging lenses with positive (+) and / or (-) refractive power. However, when multiple lenses are included, the overall optical system can become larger, and it becomes difficult to obtain excellent optical and aberration characteristics.

[0003] When an optical system includes multiple lenses, zoom and autofocus functions can be performed by controlling the position of at least one lens or a lens group including at least one lens. However, when a lens or lens group is designed to perform these functions, the amount of movement of the lens or lens group may increase exponentially. Therefore, devices including optical systems may require significant energy, and design considerations for this movement become necessary. When an optical system includes multiple lenses, the overall length and height of the optical system may increase due to the thickness, spacing, and size of the multiple lenses. Therefore, the overall thickness of a smartphone or mobile terminal device incorporating an optical system may increase, making it difficult to achieve a small size. Therefore, a new optical system capable of addressing these issues is needed. Summary of the Invention

[0004] Technical issues

[0005] Embodiments of the present invention provide an optical system and an imaging apparatus module with improved optical properties. The embodiments provide an optical system and an imaging apparatus module capable of providing an auto-focus (AF) function for subjects located at various distances. The embodiments provide an optical system and an imaging apparatus module that can be implemented in a small and compact manner. The embodiments aim to provide an imaging apparatus module suitable for a folded imaging apparatus with a thin thickness.

[0006] Technical Solutions

[0007] An optical system according to an embodiment of the present invention includes: a first lens group and a second lens group, which are sequentially arranged along the optical axis from the object side to the sensor direction and each include at least one lens, the sign of the focal length of the first lens group and the sign of the focal length of the second lens group are opposite to each other and satisfy the following expression: -1.5<f_2 / f_1 / 0 (f_1 is the focal length of the first lens group, and f_2 is the focal length of the second lens group), the effective diameter (clear aperture) of the lenses included in the first lens group and the second lens group is smaller than the diagonal length of the image sensor, and one of the first lens group and the second lens group can be disposed in the optical axis direction.

[0008] According to an embodiment of the present invention, the first lens group includes first to third lenses sequentially disposed along the optical axis from the object side to the sensor side, and the second lens group may include a fourth lens and a fifth lens sequentially disposed along the optical axis from the object side to the sensor side direction. The lens disposed closest to the object side in the first lens group may have positive (+) refractive power, and the sensor-side surface of the lens disposed closest to the object side in the first lens group may have a convex shape. The lens disposed closest to the image sensor in the second lens group may have negative (-) refractive power, and the sensor-side surface of the lens disposed closest to the image sensor in the second lens group may have a convex shape.

[0009] According to an embodiment of the present invention, the object-side surface of the lens disposed closest to the object side in the second lens group may have a concave shape. The first lens group and the second lens group may satisfy [Equation 1] 1<L_G1 / L_G2<4 (in Equation 1, L_G1 refers to the distance in the optical axis direction from the vertex of the object-side surface of the lens closest to the object among the lenses included in the first lens group to the vertex of the sensor-side surface of the lens closest to the image sensor. In addition, L_G2 refers to the distance in the optical axis direction from the vertex of the object-side surface of the lens closest to the object among the lenses included in the second lens group to the vertex of the sensor-side surface of the lens closest to the image sensor).

[0010] According to an embodiment of the present invention, the second lens group may satisfy [Equation 2] 4<TTL / L_G2<7 (in Equation 2, L_G2 refers to the length in the optical axis (OA) direction from the vertex of the object-side surface of the lens closest to the object among the lenses included in the second lens group to the vertex of the sensor-side surface of the lens closest to the image sensor, and TTL (total track length) refers to the distance in the optical axis direction from the vertex of the object-side surface of the lens closest to the object among the plurality of lenses included in the first lens group and the second lens group to the upper surface of the image sensor).

[0011] According to an embodiment of the present invention, the first lens group may include at least one lens having a non-circular shape.

[0012] According to an embodiment of the present invention, the imaging apparatus module may include an optical system and a driving member, and the driving member may control the position of the second lens group.

[0013] Beneficial Effects

[0014] The optical system and the imaging apparatus module according to the embodiment of the present invention may have improved optical properties. In detail, the effective focal length (EFL) may be controlled by moving at least one lens group among the plurality of lens groups, and the moving distance of the moving lens group may be minimized. Therefore, the amount of curvature generated may be minimized according to the moving distance of the moving lens group, thereby minimizing the deterioration of peripheral image quality. The embodiment may minimize the moving distance of the moving lens group, thereby minimizing the power consumption required for the movement of the lens group. The embodiment may use an optical system having a set shape, focal length, spacing, etc. to provide an auto-focus (AF) function for subjects located at various distances. In detail, the embodiment may provide an auto-focus function for subjects located at infinity or a close distance using a single imaging apparatus module. Within the range from infinity to the near field, the embodiment may have a constant TTL value regardless of the distance to the subject. Therefore, the optical system and the imaging apparatus module including the optical system may be provided with a relatively thin structure.

[0015] The optical system and the imaging apparatus module according to the embodiment may include at least one lens having a non-circular shape. Therefore, the optical system may have improved optical performance and may be implemented in a compact size, so that the optical system may be provided more compactly compared to an optical system having only a circular shape. According to the embodiment, the optical system and the imaging apparatus module may include an optical path changing member. Therefore, the optical system may be applied to a folded imaging apparatus that may have a relatively thin thickness, and an apparatus including the imaging apparatus may be manufactured to have a thin thickness. Brief Description of the Drawings

[0016] Figure 1This is a block diagram of an optical system according to an embodiment operating in the first mode.

[0017] Figure 2 This is a view used to illustrate the TTL (Total Track Length) and BFL (Back Focal Length) of an optical system operating in the first mode.

[0018] Figure 3 This is a configuration diagram of the optical system according to the implementation method, operating in the second mode.

[0019] Figure 4 This is a view used to illustrate the TTL and BFL of the optical system operating in the second mode.

[0020] Figure 5 This is a view used to illustrate a lens with a non-circular shape.

[0021] Figure 6 It is a graph showing the focal length and curvature aberration of the first and second lens groups in the optical system according to the embodiment.

[0022] Figure 7 It is a graph of the aberration diagram when the optical system according to the embodiment is operating in the first mode.

[0023] Figure 8 It is a graph of the aberration diagram when the optical system according to the embodiment is operating in the second mode.

[0024] Figure 9 This is a configuration diagram illustrating that the optical system according to the embodiment also includes a third lens group.

[0025] Figure 10 This diagram illustrates the application of a camera device module according to an embodiment to a mobile terminal. Detailed Implementation

[0026] Preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings. The spirit of the invention is not limited to the embodiments described herein, but can be implemented in various other forms, and one or more components can be selectively combined and substituted for use within the scope of the spirit of the invention. Furthermore, unless explicitly defined and clearly described, the terminology (including technical and scientific terms) used in the embodiments of the invention can be interpreted in the sense that is generally understood by one of ordinary skill in the art to which this invention pertains, and commonly used terms, such as those defined in dictionaries, should be interpretable in the context of the relevant art. Moreover, the terminology used in the embodiments of the invention is for illustrative purposes and is not intended to limit the invention. In this specification, unless specifically stated otherwise in the phrase, the singular form may also include the plural form, and in cases referring to at least one (or more) of A and (and) B, C, it may include one or more of all combinations that can be combined with A, B, and C. When describing components of embodiments of the invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish components from other components and should not determine the nature, order, or process of the corresponding constituent elements. Furthermore, when describing a component as "connected," "coupled," or "joined" to another component, the description can include not only direct connection, coupling, or joining to the other component, but also connection, coupling, or joining via other components between the component and the other component. Additionally, when described as being formed or disposed "above" or "below" each component, the description includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or disposed between the two components. Furthermore, when expressed as "above" or "below," it can refer to both a downward and upward direction relative to a single element.

[0027] A convex surface of a lens can refer to a lens surface in the region corresponding to the optical axis that has a convex shape, and a concave lens surface can refer to a lens surface in the region corresponding to the optical axis that has a concave shape. "Object side" can refer to the surface of the lens facing the object side relative to the optical axis, and "sensor side" can refer to the surface of the lens facing the image sensor relative to the optical axis. The vertical direction can refer to a direction perpendicular to the optical axis, and the end of the lens or lens surface can refer to the end of the effective region of the lens through which incident light passes. The center thickness of the lens can refer to the length along the optical axis between the object side and the sensor side of the lens.

[0028] Figure 1 This is a block diagram of an optical system according to an embodiment, operating in the first mode. Figure 2This is a view used to illustrate the TTL (Total Track Length) and BFL (Back Focal Length) of the optical system operating in the first mode. Figure 3 This is a configuration diagram of the optical system according to the embodiment, operating in the second mode. Figure 4 This is a diagram illustrating the TTL and BFL of an optical system operating in the second mode. Figure 5 This is a view used to illustrate a lens with a non-circular shape. Figure 6 This is a graph showing the focal length and curvature aberration of the first and second lens groups in the optical system according to an embodiment. Figure 7 and Figure 8 It is a graph of aberration diagrams when the optical system according to the embodiment operates in the first mode and the second mode.

[0029] Reference Figures 1 to 4 The optical system 1000 according to the embodiment may include multiple lens groups. Specifically, the optical system 1000 may include multiple lens groups, each comprising at least one lens. For example, the optical system 1000 may include a first lens group G1, a second lens group G2, and an image sensor 300 arranged sequentially along the optical axis OA from the object side to the sensor direction. The first lens group G1 may have positive (+) refractive power or negative (-) refractive power. For example, the first lens group G1 may have positive (+) refractive power. Furthermore, the second lens group G2 may have negative (-) refractive power or positive (+) refractive power. The second lens group G2 may have a refractive power opposite to that of the first lens group G1. For example, when the first lens group G1 has positive (+) refractive power as described above, the second lens group G2 may have negative (-) refractive power. The first lens group G1 and the second lens group G2 may have different focal lengths. In detail, since the first lens group G1 and the second lens group G2 have opposite refractive powers, the focal lengths of the second lens group G2 and the first lens group G1 can have opposite signs (+, -). The focal lengths of the first lens group G1 and the second lens group G2 can satisfy the following formula.

[0030] [Formula]-1.5 <f_2 / f_1<0

[0031] (f_1 is the focal length of the first lens group, and f_2 is the focal length of the second lens group.)

[0032] Since the focal lengths of the first lens group G1 and the second lens group G2 satisfy the aforementioned range, the optical system 1000 can provide autofocus (AF) functionality for objects located at infinity or near. Furthermore, because the first lens group G1 and the second lens group G2 satisfy the aforementioned focal lengths, the amount of curvature that occurs depending on the distance the moving lens groups travel can be minimized. Therefore, the optical system 1000 can minimize the degradation of image quality in the peripheral region when the focus changes from infinity to the near field.

[0033] The first lens group G1 may include at least one lens. The first lens group G1 may include multiple lenses. Specifically, the first lens group G1 may include two or more lenses. The multiple lenses included in the first lens group G1 may have a defined interval. Specifically, the interval between the multiple lenses included in the first lens group G1 may be constant and will not change in the operating modes described later. For example, the interval between the first lens 110 and the second lens 120, and the interval between the second lens 120 and the third lens 130, may be constant and will not change in the operating modes described later. Here, the interval between the multiple lenses may refer to the distance between the centers of adjacent lenses in the direction of the optical axis OA.

[0034] The second lens group G2 may include at least one lens. The second lens group G2 may include multiple lenses. Specifically, the second lens group G2 may include two or more lenses. The second lens group G2 may include fewer or the same number of lenses as the first lens group G1. The multiple lenses included in the second lens group G2 may have a defined interval. Specifically, the interval between the multiple lenses included in the second lens group G2 may be constant and will not change under the operating modes described later. For example, the interval between the fourth lens 140 and the fifth lens 150 may be constant and will not change according to the operating modes described later. Here, the interval between the multiple lenses may refer to the distance between the centers of adjacent lenses in the direction of the optical axis OA.

[0035] The optical system 1000 may include multiple lens groups G1, G2 and an image sensor 300 arranged sequentially from the object side to the sensor direction. Furthermore, the optical system 1000 includes four or more lenses 100 included in the lens groups G1 and G2, such as a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, and a fifth lens 150. In this case, the first lens group G1 may include the first to third lenses 110, 120, and 130, and the second lens group G2 may include the fourth lens 140 and the fifth lens 150. The first to fifth lenses 110, 120, 130, 140, and 150 and the image sensor 300 may be arranged sequentially along the optical axis OA of the optical system 1000.

[0036] Each of the plurality of lenses 100 may include an effective region and an ineffective region. The effective region may be the area through which light incident on each of the first to fifth lenses 110, 120, 130, 140, 150 passes. That is, the effective region may be the area where incident light is refracted to achieve optical properties. The ineffective region may be located around the effective region. The ineffective region may be an area where light does not incident. That is, the ineffective region may be a region independent of optical properties. Furthermore, the ineffective region may be an area fixed to a lens barrel (not shown) for housing the lens.

[0037] Image sensor 300 can detect light. Image sensor 300 can detect light passing sequentially through multiple lenses 100, such as first lenses to fifth lenses 110, 120, 130, 140, 150. Image sensor 300 may include a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS).

[0038] The optical system 1000 may also include a filter (not shown). The filter may be disposed between the plurality of lenses 100 and the image sensor 300. The filter may be disposed between the image sensor 300 and the second lens group G2 closest to the image sensor 300 among the plurality of lens groups. For example, the filter may be disposed between the image sensor 300 and the last lens in the second lens group G2 closest to the image sensor 300 among the plurality of lenses 100. The filter may include at least one of an infrared filter and an optical filter such as a cover glass. The filter allows light with a defined wavelength band to pass through and filters light with different wavelength bands. When the filter includes an infrared filter, radiant heat emitted from external light can be prevented from being transmitted to the image sensor 300. Furthermore, the filter can transmit visible light and reflect infrared light.

[0039] The optical system 1000 may include an aperture stop (not shown). The aperture stop can control the amount of light incident on the optical system 1000. The aperture stop may be located in front of the first lens 110, or between two lenses selected from the first to the fifth lenses 110, 120, 130, 140, 150. For example, the aperture stop may be positioned between the first lens 110 and the second lens 120. Furthermore, at least one lens selected from the first to the fifth lenses 110, 120, 130, 140, 150 can serve as an aperture stop. For example, the object-side surface or sensor-side surface of one of the lenses selected from the first to the fifth lenses 110, 120, 130, 140, 150 can be used as an aperture stop for controlling the amount of light. For example, the object-side surface (third surface S3) of the third lens 120 can be used as an aperture stop.

[0040] The optical system 1000 may also include a light path changing component (not shown). The light path changing component can change the path of light by reflecting externally incident light. The light path changing component may include a reflector and a prism. For example, the light path changing component may include a right-angle prism. When the light path changing component includes a right-angle prism, it can change the path of incident light by reflecting it at a 90-degree angle. The light path changing component can be positioned closer to the object side than the plurality of lenses 100. That is, when the optical system 1000 includes a light path changing component, the light path changing component, first lens 110, second lens 120, third lens 130, fourth lens 140, fifth lens 150, filter, and image sensor 300 can be arranged in the following order from the object side to the sensor direction. The light path changing component can change the path of externally incident light in a set direction. For example, the aforementioned light path changing member can change the path of light incident on the light path changing member along the first direction to a second direction that is the arrangement direction of the plurality of lenses 100 (the direction in which the plurality of lenses 100 are spaced apart, i.e., the direction of the optical axis (OA) in the figure). When the optical system 1000 includes the light path changing member, the optical system can be applied to a folding camera device that can reduce the thickness of the imaging device. Specifically, when the optical system 1000 includes the light path changing member, light incident in a direction perpendicular to the surface of the device to which the optical system 1000 is applied can be changed in a direction parallel to the surface of the device. Therefore, the optical system 1000 including the plurality of lenses 100 can have a thinner thickness in the device, and thus the device can be provided thinner. For example, when the optical system 1000 does not include the light path changing member, the plurality of lenses 100 can be arranged in the device to extend in a direction perpendicular to the surface of the device. Therefore, the optical system 1000 including the plurality of lenses 100 has a high height in the direction perpendicular to the surface of the device, and therefore it may be difficult to form a thin optical system 1000 and a device including the optical system. However, when the optical system 1000 includes a light path changing member, the plurality of lenses 100 can be arranged to extend in a direction parallel to the surface of the device. That is, the optical system 1000 is arranged such that the optical axis OA is parallel to the surface of the device, and can be applied to a folding camera device. Therefore, the optical system 1000 including the plurality of lenses 100 can have a low height in a direction perpendicular to the surface of the device. Therefore, the camera device including the optical system 1000 can have a thin thickness within the device, and the thickness of the device can be reduced.

[0041] Referring again to the plurality of lenses 100, the optical system 1000 may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a filter, and an image sensor 300 arranged sequentially along the optical axis OA from the object side to the sensor side. Among the plurality of lenses 100, the first lens 110 may be positioned closest to the object side, and the fifth lens 150 may be positioned closest to the image sensor 300.

[0042] The first lens 110 may have positive (+) refractive power or negative (-) refractive power. The first lens 110 may comprise a plastic or glass material. For example, the first lens 110 may be made of a plastic material. The first lens 110 may comprise a first surface S1 defined as the object-side surface and a second surface S2 defined as the sensor-side surface. The first surface S1 may be convex, and the second surface S2 may be concave. That is, the first lens 110 may have a meniscus shape convex toward the object side. Alternatively, the first surface S1 may be convex, and the second surface S2 may be convex. That is, the first lens 110 may have a shape where both surfaces are convex. At least one of the first surface S1 and the second surface S2 may be aspherical. For example, both the first surface S1 and the second surface S2 may be aspherical.

[0043] The second lens 120 may have positive (+) refractive power or negative (-) refractive power. The second lens 120 may comprise a plastic or glass material. For example, the second lens 120 may be made of a plastic material. The second lens 120 may include a third surface S3 defined as the object-side surface and a fourth surface S4 defined as the sensor-side surface. The third surface S3 may be convex, and the fourth surface S4 may be concave. That is, the second lens 120 may have a meniscus shape convex toward the object side. Alternatively, the third surface S3 may be convex, and the fourth surface S4 may be convex. That is, the second lens 120 may have a shape where both surfaces are convex. Alternatively, the third surface S3 may be concave, and the fourth surface S4 may be convex. That is, the second lens 120 may have a meniscus shape convex toward the sensor. Alternatively, the third surface S3 may be concave, and the fourth surface S4 may be concave. That is, the second lens 120 may have a shape where both surfaces are concave. At least one of the third surface S3 and the fourth surface S4 may be aspherical. For example, both the first surface S3 and the fourth surface S4 can be aspherical.

[0044] The third lens 130 may have positive (+) refractive power or negative (-) refractive power. The third lens 130 may comprise a plastic or glass material. For example, the third lens 130 may be made of a plastic material. The third lens 130 may include a fifth surface S5 defined as the object-side surface and a sixth surface S6 defined as the sensor-side surface. The fifth surface S5 may be convex, and the sixth surface S6 may be concave. That is, the third lens 130 may have a meniscus shape convex toward the object side. Alternatively, the fifth surface S5 may be convex, and the sixth surface S6 may be convex. That is, the third lens 130 may have a shape where both surfaces are convex. Alternatively, the fifth surface S5 may be concave, and the sixth surface S6 may be convex. That is, the third lens 130 may have a meniscus shape convex toward the sensor. Alternatively, the fifth surface S5 may be concave, and the sixth surface S6 may be concave. That is, the third lens 130 may have a shape where both surfaces are concave. At least one of the fifth surface S5 and the sixth surface S6 may be aspherical. For example, both the fifth surface S5 and the sixth surface S6 can be aspherical.

[0045] The fourth lens 140 may have positive (+) refractive power or negative (-) refractive power. The fourth lens 140 may comprise a plastic or glass material. For example, the fourth lens 140 may be made of a plastic material. The fourth lens 140 may comprise a seventh surface S7 defined as the object-side surface and an eighth surface S8 defined as the sensor-side surface. The seventh surface S7 may be concave, and the eighth surface S8 may be convex. That is, the fourth lens 140 may have a meniscus shape convex toward the sensor. Alternatively, the seventh surface S7 may be concave, and the eighth surface S8 may be concave. That is, the fourth lens 140 may have a shape where both surfaces are concave. At least one of the seventh surface S7 and the eighth surface S8 may be aspherical. For example, both the seventh surface S7 and the eighth surface S8 may be aspherical.

[0046] The fifth lens 150 may have positive (+) refractive power or negative (-) refractive power. The fifth lens 150 may comprise a plastic or glass material. For example, the fifth lens 150 may be made of a plastic material. The fifth lens 150 may comprise a ninth surface S9 defined as the object-side surface and a tenth surface S10 defined as the sensor-side surface. The ninth surface S9 may be convex, and the tenth surface S10 may be convex. That is, the fifth lens 150 may have a shape where both surfaces are convex. Alternatively, the ninth surface S9 may be concave, and the tenth surface S10 may be convex. That is, the fifth lens 150 may have a meniscus shape convex toward the sensor. At least one of the ninth surface S9 and the tenth surface S10 may be aspherical. For example, both the ninth surface S9 and the tenth surface S10 may be aspherical.

[0047] At least one of the plurality of lenses 100 may have a non-circular shape. For example, the first lens 110 may have a non-circular shape. Specifically, the first surface S1 and the second surface S2 of the first lens 110 may have a non-circular shape, and the third to tenth surfaces S3, S4, S5, S6, S7, S8, S9, and S10 of the second to fifth lenses 120, 130, 140, and 150 may have a circular shape. That is, when each of the first surface S1 and the second surface S2 is viewed from a frontal view corresponding to the optical axis OA, the effective area of ​​each lens surface may have a non-circular shape.

[0048] Reference Figure 5The effective area of ​​each of the first surfaces S1 and S2 of the first lens 110 may include first edges to fourth edges A1, A2, A3, and A4. First edges A1 and A2 may be edges facing each other in a first direction (x-axis direction) perpendicular to the optical axis OA. First edges A1 and A2 may have curved shapes. First edges A1 and A2 may be configured to have curved shapes with the same length and curvature. That is, first edges A1 and A2 may have symmetrical shapes based on a virtual line passing through the optical axis OA and extending in a second direction (y-axis direction). Third edges A3 and A4 may be edges facing each other in a second direction (y-axis direction) perpendicular to both the optical axis OA and the first direction. Third edges A3 and A4 may be edges connecting the ends of first edges A1 and A2. Third edges A3 and A4 may have straight shapes. Third edges A3 and A4 may have the same length and may be parallel to each other. That is, the third edge A3 and the fourth edge A4 can have a symmetrical shape based on a virtual line passing through the optical axis OA and extending in the first direction (x-axis direction). The first surface S1 and the second surface S2 include the first edge to the fourth edge A1, A2, A3, A4, and therefore can have a non-circular shape, for example, a D-cut shape. During the manufacturing of the first lens 110, the first surface S1 and the second surface S2 can have the aforementioned non-circular shape. For example, when the first lens 110 comprises a plastic material, the first lens can be manufactured into the aforementioned non-circular shape during the injection molding process. Alternatively, the first lens 110 can be manufactured into a circular shape by the injection molding process, and in a subsequent cutting process, it can have a third edge A3 and a fourth edge A4 cut from a portion of the first surface S1 and the second surface S2.

[0049] Therefore, the effective area of ​​each of the first surface S1 and the second surface S2 can have a set size. For example, the length (aperture diameter, CA) of the first virtual straight line passing through the optical axis OA and connecting the first edge A1 and the second edge A2 can be longer than the length (net height, CH) of the second virtual straight line passing through the optical axis OA and connecting the third edge A3 and the fourth edge A4. Here, the length CA of the first straight line can refer to the aperture diameter CA of each of the first surface S1 and the second surface S2, and the length CH of the second straight line can refer to the size (net height) of the minimum effective diameter of each of the first surface S1 and the second surface S2. For example, the size CH of the minimum effective diameter of the first surface S1 and the second surface S2 can be approximately 4 mm. In the above description, it is described that the effective areas of the first surface S1 and the second surface S2 have a non-circular shape, but the present invention is not limited thereto, and each of the effective areas of the first surface S1 and the second surface S2 can have a circular shape, and the ineffective area of ​​each of the first surface S1 and the second surface S2 can have a non-circular shape.

[0050] The imaging device module (not shown) according to the embodiment may include the optical system 1000 described above. The imaging device module can move at least one of the plurality of lenses 100 included in the optical system 1000 in the optical axis OA direction. Specifically, the imaging module may include a drive member (not shown) connected to the optical system 1000. The drive member can move at least one lens group in the optical axis OA direction according to an operating mode. The operating mode may include a first mode defined as an infinity mode and a second mode defined as a near mode. The drive member can move at least one lens group according to the first mode and the second mode, and can control at least one of the intervals between the first lens group G1 and the second lens group G2 and between the second lens group G2 and the image sensor 300. Here, near distance may refer to a distance of about 40 mm or less. Specifically, near distance may refer to a distance of about 30 mm or less.

[0051] For example, such as Figures 1 to 4 As shown, the first lens group G1 can be fixed, and the second lens group G2 can be configured to be movable by the driving force of the driving member. In this case, the spacing between the lenses in each lens group included in the first lens group G1 and the second lens group G2 can remain constant. Specifically, regardless of the driving force of the driving member, the spacing between the fourth lens 140 and the fifth lens 150 included in the second lens group G2 can remain constant when the second lens group G2 moves. Therefore, the total track length (TTL) of the optical system 1000 can be constant, and the back focal length (BFL) of the optical system 1000 can vary according to the applied driving force.

[0052] When the first lens group G1 is fixed in the optical system 1000 and the second lens group G2 is configured to be movable, the plurality of lenses 100 in each lens group, including the first lens group G1 and the second lens group G2, can have a set effective diameter (aperture). Specifically, each of the first to tenth surfaces S1, S2, S3, S4, S5, S6, S7, S8, S9, and S10 can have a set effective diameter. The effective diameter of each of the first to tenth surfaces S1, S2, S3, S4, S5, S6, S7, S8, S9, and S10 can be smaller than the size of the image sensor 300, for example, smaller than the diagonal length (ImgH) of the image sensor 300.

[0053] In the optical system 1000, the lens surface with the largest effective diameter may be included in the fixed lens group. For example, the lens surface with the largest effective diameter among the first to tenth surfaces S1, S2, S3, S4, S5, S6, S7, S8, S9, and S10 may be included in the first lens group G1. The lens surface with the smallest effective diameter may be included in the movable lens group. Specifically, the lens surface with the smallest effective diameter among the first to tenth surfaces S1, S2, S3, S4, S5, S6, S7, S8, S9, and S10 may be included in the second lens group G2. For example, the effective diameter of the eighth surface S8 among the first to tenth surfaces S1, S2, S3, S4, S5, S6, S7, S8, S9, and S10 may be the smallest.

[0054] As described above, the first lens group G1 can have positive (+) refractive power, and the second lens group G2 can have negative (-) refractive power. In this case, when the imaging device module changes from the first mode to the second mode, the second lens group G2 can move from the first lens group G1 toward the image sensor 300. Specifically, the second lens group G2 can move to a position closer to the image sensor 300. Alternatively, when the first lens group G1 has negative (-) refractive power and the second lens group G2 has positive (+) refractive power, the second lens group G2 can move in the opposite direction, for example, in the direction from the image sensor 300 toward the first lens group G1. Specifically, the second lens group G2 can move away from the image sensor 300 and move to a position closer to the first lens group G1.

[0055] According to the embodiment, the camera device module controls the position of at least one of the plurality of lens groups G1, G2 to control the interval between lens groups G1, G2 and change the effective focal length (EFL) of the optical system 1000. Therefore, the camera device module can control the effective focal length (EFL) according to the distance from the subject and can effectively provide autofocus (AF) function for subjects located at infinity or near distance.

[0056] Although not shown in the figure, the second lens group G2 can be fixed, and the first lens group G1 can be configured to be movable by the driving force of the driving member. In this case, the spacing between the lenses in each lens group included in the first lens group G1 and the second lens group G2 can be constant and unchanged. Specifically, regardless of the driving force of the driving member, when the first lens group G1 moves, each of the spacings between the first lens 110 and the second lens 120, and between the second lens 120 and the third lens 130, included in the first lens group G1, can be constant. Therefore, the back focal length (BFL) of the optical system 1000 can be constant, and the total track length (TTL) of the optical system 1000 can vary.

[0057] The optical system 1000 according to the embodiment can satisfy at least one of the following formulas. Therefore, the optical system 1000 according to the embodiment can have improved aberration characteristics, and thus improved optical characteristics. In addition, the embodiment can effectively provide autofocus (AF) functionality for subjects located from short distances to infinity, and can be provided in a thinner and more compact manner.

[0058] [Formula 1]

[0059] -1.5 <f_2 / f_1<0

[0060] In Equation 1, f_1 refers to the focal length of the first lens group G1, and f_2 refers to the focal length of the second lens group G2.

[0061] [Equation 2]

[0062] n_G2≤n_G1

[0063] In Equation 2, n_G1 refers to the number of lenses included in the first lens group G1, and n_G2 refers to the number of lenses included in the second lens group G2.

[0064] [Formula 3]

[0065] 1 <L_G1 / L_G2<4

[0066] In Equation 3, L_G1 refers to the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object in the lenses included in the first lens group G1 to the vertex of the sensor-side surface of the lens closest to the image sensor 300. Furthermore, L_G2 refers to the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object in the lenses included in the second lens group G2 to the vertex of the sensor-side surface of the lens closest to the image sensor 300.

[0067] [Formula 4]

[0068] 1.5 <TTL / L_G1<3.5

[0069] In Equation 4, L_G1 refers to the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object among the lenses included in the first lens group G1 to the vertex of the sensor-side surface of the lens closest to the image sensor 300. TTL refers to the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object among the plurality of lenses 100 to the upper surface of the image sensor 300.

[0070] [Formula 5]

[0071] 4 <TTL / L_G2<7

[0072] In Equation 5, L_G2 refers to the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object among the lenses included in the second lens group G2 to the vertex of the sensor-side surface of the lens closest to the image sensor 300. TTL refers to the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object among the plurality of lenses 100 to the upper surface of the image sensor 300.

[0073] [Formula 6]

[0074] 0.8 <CA_L1S2 / CA_L1S1<1

[0075] In Equation 6, CA_L1S1 refers to the effective diameter (CA: light-transmitting aperture) of the object-side surface (first surface S1) of the first lens 110, and CA_L1S2 refers to the effective diameter (CA: light-transmitting aperture) of the sensor-side surface (second surface S2) of the first lens 110.

[0076] [Formula 7]

[0077] 0.5 <CA_L3S1 / CA_L1S1<0.8

[0078] In Equation 7, CA_L1S1 refers to the effective diameter (CA: aperture) of the object-side surface (first surface S1) of the first lens 110, and CA_L3S1 refers to the effective diameter (CA: aperture) of the object-side surface (fifth surface S5) of the third lens 130.

[0079] [Formula 8]

[0080] CA_L1S1>CA_L1S2>CA_L3S1>CA_L3S2>CA_L2S1>CA_L2S2

[0081] In Equation 8, CA_L1S1 refers to the effective diameter (CA: aperture) of the object-side surface (first surface S1) of the first lens 110, and CA_L1S2 refers to the effective diameter (CA: aperture) of the sensor-side surface (second surface S2) of the first lens 110. Furthermore, CA_L2S1 refers to the effective diameter (CA: aperture) of the object-side surface (third surface S3) of the second lens 120, and CA_L2S2 refers to the effective diameter (CA: aperture) of the sensor-side surface (fourth surface S4) of the second lens 120. Additionally, CA_L3S1 refers to the effective diameter (CA: aperture) of the object-side surface (fifth surface S5) of the third lens 110, and CA_L3S2 refers to the effective diameter (CA: aperture) of the sensor-side surface (sixth surface S6) of the third lens 130.

[0082] [Formula 9]

[0083] 1 <T12 / L1_CT<2.5

[0084] In Equation 9, T12 refers to the center interval between the first lens 110 and the second lens 120, and L1_CT refers to the center thickness of the first lens 110.

[0085] [Formula 10]

[0086] 1 <L1_CT / L2_CT<10

[0087] In Equation 10, L1_CT refers to the center thickness of the first lens 110, and L2_CT refers to the center thickness of the second lens 120.

[0088] [Equation 11]

[0089] 0.1 <L2_CT / L3_CT<1

[0090] In Equation 11, L2_CT refers to the center thickness of the second lens 120, and L3_CT refers to the center thickness of the third lens 130.

[0091] [Equation 12]

[0092] 0.1 <L4_CT / L5_CT<1

[0093] In Equation 12, L4_CT refers to the center thickness of the fourth lens 140, and L5_CT refers to the center thickness of the fifth lens 150.

[0094] [Equation 13]

[0095] 2 <L5_CT / T45<4

[0096] In Equation 13, L5_CT refers to the center thickness of the fifth lens 150, and T45 refers to the center spacing between the fourth lens 140 and the fifth lens 150.

[0097] [Formula 14]

[0098] 0.1 <L_G1 / TTL<1

[0099] In Equation 14, L_G1 refers to the distance of the first lens group G1 along the optical axis OA. Specifically, L_G1 is the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object in the first lens group G1 to the vertex of the sensor-side surface of the last lens closest to the image sensor. TTL refers to the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object among the plurality of lenses 100 to the upper surface of the image sensor 300.

[0100] [Formula 15]

[0101] 0.6 <CH_L1S1 / CA_L1S1<1

[0102] In Equation 15, CA_L1S1 refers to the size of the maximum effective diameter (CA: aperture) of the object-side surface (first surface S1) of the first lens 110, and CH_L1S1 refers to the size of the minimum effective diameter (CH: net height) of the object-side surface (first surface S1) of the first lens 110.

[0103] [Formula 16]

[0104] 0.05 <L_G2 / TTL<1

[0105] In Equation 16, L_G2 refers to the distance of the second lens group G2 along the optical axis OA. Specifically, L_G2 is the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object in the second lens group G2 to the vertex of the sensor-side surface of the last lens closest to the image sensor. TTL refers to the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object among the plurality of lenses 100 to the upper surface of the image sensor 300.

[0106] [Equation 17]

[0107] 3 <L_G1 / md1<6.5

[0108] In Equation 17, L_G1 refers to the distance of the first lens group G1 along the optical axis OA. Specifically, L_G1 is the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object in the first lens group G1 to the vertex of the sensor-side surface of the last lens closest to the image sensor. md1 refers to the distance moved by the second lens group G2 when changing from infinity mode (first mode) to near mode (second mode) or from near mode (second mode) to infinity mode (first mode). Specifically, md1 is the difference between the second interval d2 and the first interval d1.

[0109] [Formula 18]

[0110] 1 <L_G2 / md1<3.5

[0111] In Equation 18, L_G2 refers to the distance of the second lens group G2 along the optical axis OA. Specifically, L_G2 is the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object in the second lens group G2 to the vertex of the sensor-side surface of the last lens closest to the image sensor. md1 refers to the distance the second lens group G2 moves when changing from infinity mode (first mode) to near mode (second mode) or from near mode (second mode) to infinity mode (first mode). Specifically, md1 is the difference between the second interval d2 and the first interval d1.

[0112] [Formula 19]

[0113] 0.15 <md1 / CA_Sa<1

[0114] In Equation 19, md1 refers to the distance the moving second lens group G2 travels when changing from infinity mode (first mode) to near mode (second mode) or from near mode (second mode) to infinity mode (first mode). Specifically, md1 refers to the difference between the second interval d2 and the first interval d1. CA_Sa refers to the effective diameter value of the lens surface with the largest effective diameter (aperture) among the lens surfaces of the plurality of lenses 100.

[0115] [Formula 20]

[0116] 0.3 <md1 / CA_Sb<1

[0117] In Equation 20, md1 refers to the distance the moving second lens group G2 travels when changing from infinity mode (first mode) to near mode (second mode) or from near mode (second mode) to infinity mode (first mode). Specifically, md1 refers to the difference between the second interval d2 and the first interval d1. CA_Sb refers to the effective diameter value of the lens surface with the smallest effective diameter (aperture) among the lens surfaces of the plurality of lenses 100.

[0118] [Equation 21]

[0119] 2 <TTL / md1<20

[0120] In Equation 21, TTL (Total Track Length) refers to the distance along the optical axis (OA) from the vertex of the object-side surface of the lens closest to the object among the plurality of lenses 100 to the upper surface of the image sensor 300. md1 refers to the distance moved by the second lens group G2 when changing from infinity mode (first mode) to near mode (second mode) or from near mode (second mode) to infinity mode (first mode). Specifically, md1 refers to the difference between the second interval d2 and the first interval d1.

[0121] [Equation 22]

[0122] 0.1 <md1 / ImgH<1

[0123] In Equation 22, md1 refers to the distance the moving second lens group G2 travels when changing from infinity mode (first mode) to near mode (second mode) or from near mode (second mode) to infinity mode (first mode). Specifically, md1 refers to the difference between the second interval d2 and the first interval d1. ImgH refers to the vertical distance of the optical axis OA from the 0-field region of the image sensor 300 to the 1.0-field region of the image sensor 300. In other words, ImgH refers to the diagonal length of the effective area of ​​the image sensor 300.

[0124] [Equation 23]

[0125] 0.1 <CA_Sa / ImgH<1

[0126] In Equation 23, CA_Sa refers to the effective diameter value of the lens surface with the largest effective diameter (aperture) among the lens surfaces of the plurality of lenses 100, and ImgH refers to the vertical distance of the optical axis OA from the 0 field region of the image sensor 300 to the 1.0 field region of the image sensor 300. That is, ImgH refers to the diagonal length of the effective area of ​​the image sensor 300.

[0127] [Equation 24]

[0128] 0.2 <CA_Sb / ImgH<0.9

[0129] In Equation 24, CA_Sb refers to the effective diameter value of the lens surface with the smallest effective diameter (aperture) among the lens surfaces of the plurality of lenses 100, and ImgH refers to the vertical distance of the optical axis OA from the 0 field region of the image sensor 300 to the 1.0 field region of the image sensor 300. That is, ImgH refers to the diagonal length of the effective area of ​​the image sensor 300.

[0130] [Equation 25]

[0131] 10 <EFL1 / T34_1<60

[0132] In Equation 25, EFL1 refers to the effective focal length EFL of the optical system 1000 when operating in the first mode (infinity mode), and T34_1 refers to the center spacing between the first lens group G1 and the second lens group G2 when operating in the first mode (infinity mode). Specifically, T34_1 refers to the center spacing between the third lens 130 and the fourth lens 140.

[0133] [Equation 26]

[0134] 1 <EFL1 / BFL1<5

[0135] In Equation 26, EFL1 refers to the effective focal length EFL of the optical system 1000 when operating in the first mode (infinity mode), and BFL1 refers to the distance along the optical axis (OA) from the vertex of the sensor-side surface of the last lens to the upper surface of the image sensor 300 when operating in the first mode (infinity mode). Specifically, BFL1 refers to the distance along the optical axis (OA) in the first mode from the vertex of the sensor-side surface (tenth surface S10) of the fifth lens 150 to the upper surface of the image sensor 300.

[0136] [Equation 27]

[0137] 5 <EFL1 / md1<18

[0138] In Equation 27, EFL1 refers to the effective focal length (EFL) of the optical system 1000 when operating in the first mode (infinity mode), and md1 refers to the distance the moving second lens G2 travels when changing from infinity mode (first mode) to near mode (second mode) or from near mode (second mode) to infinity mode (first mode). Specifically, md1 refers to the difference between the second interval d2 and the first interval d1.

[0139] [Equation 28]

[0140] 2 <EFL2 / T34_2<8

[0141] In Equation 28, EFL2 refers to the effective focal length (EFL) of the optical system 1000 when operating in the second mode (near mode), and T34_2 refers to the center spacing between the first lens group G1 and the second lens group G2 when operating in the second mode (near mode). Specifically, T34_2 refers to the center spacing between the third lens 130 and the fourth lens 140.

[0142] [Equation 29]

[0143] 1 <EFL2 / BFL2<4

[0144] In Equation 29, EFL2 refers to the effective focal length (EFL) of the optical system 1000 when operating in the second mode (near mode), and BFL2 refers to the distance along the optical axis (OA) from the vertex of the sensor-side surface of the last lens to the upper surface of the image sensor 300 when operating in the second mode (near mode). Specifically, BFL2 refers to the distance along the optical axis (OA) in the second mode from the vertex of the sensor-side surface (tenth surface S10) of the fifth lens 150 to the upper surface of the image sensor 300.

[0145] [Formula 30]

[0146] 3 <EFL2 / md1<12

[0147] In Equation 30, EFL2 refers to the effective focal length (EFL) of the optical system 1000 when operating in the second mode (near mode), and md1 refers to the distance the moving second lens group G2 travels when changing from infinity mode (first mode) to near mode (second mode) or from near mode (second mode) to infinity mode (first mode). Specifically, md1 refers to the difference between the second interval d2 and the first interval d1.

[0148] The implementation can satisfy at least one, two, or more of Equations 1 to 30. Therefore, the optical system 1000 and the imaging device module can have improved optical properties. Furthermore, by satisfying at least one of Equations 1 to 30, the amount of curvature caused by the movement of the lens group is minimized, and autofocus (AF) functionality is provided for subjects located at various distances. Moreover, by satisfying at least one of Equations 1 to 30, the implementation can be configured with a slim structure. The optical system 1000 and the imaging device module according to the implementation can have excellent curvature aberration characteristics by satisfying Equation 1 above.

[0149] [Table 1]

[0150]

[0151]

[0152] Refer to Table 1 and Figure 6 The ratio of the focal length f_1 of the first lens group G1 to the focal length f_2 of the second lens group G2 can be the same as described above. For example, at points where the focal lengths (f_2 / f_1) of the two lens groups G1 and G2 are greater than or equal to -10, the curvature aberration increases as it approaches -1.5. Figure 6 The region from left to right can approach zero (0). However, it can be seen that as the focal lengths (f_2 / f_1) of the two lens groups G1 and G2 change from -1.5 to 0 ( Figure 6 (From left to right in the image), curvature aberration diverges to zero (0) at positive (+) infinity. When the value of Equation 1 (f_2 / f_1) is less than -1.5, curvature aberration diverges to negative (-) infinity, thus potentially eliminating the optically usable area and significantly reducing the optical properties of the optical system 1000. However, when the value of Equation 1 (f_2 / f_1) satisfies the aforementioned range, curvature aberration converges to zero. Therefore, when the focal point changes from infinity to near, the implementation can achieve improved optical properties by minimizing the amount of curvature generated by the movement of the lens group.

[0153] The plurality of lenses 100 according to the embodiments will be described in more detail below. In particular, the plurality of lenses 100 when the first lens group G1 is fixed and the second lens group G2 is set to be movable will be described in detail.

[0154] [Table 2]

[0155]

[0156]

[0157] [Table 3]

[0158] TTL(TTL1) 17.3029mm BFL (BFL1) 7.6011mm EFL (EFL1) 17.1mm ImgH 6.428mm First interval (d1) 0.4312mm

[0159] Table 2 shows the lens information when the camera module operates in the first mode as infinity mode. Specifically, Table 1 shows the radius of curvature, thickness of each lens, center spacing between lenses 110, 120, 130, 140, and 150 in infinity mode, refractive index, Abbe number, and effective diameter (aperture). Table 3 shows the size of the image sensor 300 and data regarding TTL, BFL (BFL1), EFL (EFL1), field of view (FOV), and F-number when operating in infinity mode.

[0160] Referring to Table 2, the first lens 110 of the optical system 1000 according to the embodiment can have positive (+) refractive power. The first surface S1 of the first lens 110 can be convex, and the second surface S2 can be convex. The first lens 110 can have a shape that is convex on both sides. The first surface S1 can be aspherical, and the second surface S2 can be aspherical. The second lens (120) can have negative (-) refractive power. The third surface S3 of the second lens 120 can be concave, and the fourth surface S4 can be concave. The second lens 120 can have a concave shape on both sides. The third surface S3 can be aspherical, and the fourth surface S4 can be aspherical. The third lens 130 can have positive (+) refractive power. The fifth surface S5 of the third lens 130 can be convex, and the sixth surface S6 can be convex. The third lens 130 can have a shape that is convex on both sides. The fifth surface S5 can be aspherical, and the sixth surface S6 can be aspherical. The fourth lens 140 can have negative (-) refractive power. The seventh surface S7 of the fourth lens 140 may be concave, and the eighth surface S8 may be concave. The fourth lens 140 may have a concave shape on both sides. The seventh surface S7 may be aspherical, and the eighth surface S8 may be aspherical. The fifth lens 150 may have negative (-) refractive power. The ninth surface S9 of the fifth lens 150 may be convex, and the tenth surface S10 may be convex. The fifth lens 150 may have a convex shape on both sides. The ninth surface S9 may be aspherical, and the tenth surface S10 may be aspherical.

[0161] Referring to Tables 2 and 3, the camera module can operate in infinity mode to acquire information about a subject located at infinity. Specifically, the drive member can operate in infinity mode by controlling the position of at least one of the multiple lens groups. For example, when the camera module operates in infinity mode, the first lens group G1 can be fixed, and the second lens group G2 can be moved by the driving force of the drive member. Specifically, in infinity mode, the second lens group G2 can be positioned at a first position. In this case, when the initial position of the second lens group G2 is not the first position corresponding to the infinity mode, the second lens group G2 can be moved to the first position. That is, the second lens group G2 can be positioned in a region spaced from the first lens group G1 by the driving force of the drive member, at a first interval d1. Here, the first interval d1 can refer to the center interval between the third lens 130 and the fourth lens 140. Alternatively, when the initial position of the second lens group G2 is the first position, the second lens group G2 can be positioned at the first position without moving independently. Therefore, the second lens group G2 can be disposed in a region spaced from the first lens group G1 by a first interval d1. When the imaging device module operates in infinity mode, the optical system 1000 can have a first TTLTTL1 defined as the TTL value at a first position and a first BFL BFL1 defined as the BFL value, and can have a first EFLEFL1 defined as the effective focal length EFL.

[0162] The optical system 1000 can have, for example Figure 7 The excellent aberration characteristics are shown. In detail, Figure 7 This is a graph showing the aberration characteristics of the optical system 1000 operating in the first mode (infinity mode), and it is a graph measuring spherical aberration (longitudinal spherical aberration), astigmatism curve, and distortion aberration from left to right. Figure 7 In the diagram, the X-axis indicates focal length (mm) or distortion (%), and the Y-axis indicates the image height. Furthermore, the spherical aberration graph is a graph of light in the wavelength bands of approximately 435 nm, 486 nm, 546 nm, 587 nm, and 656 nm, while the astigmatism and distortion aberration graphs are graphs of light in the wavelength band of 546 nm.

[0163] [Table 4]

[0164]

[0165] [Table 5]

[0166] TTL (TTL2) 17.3029mm BFL (BFL2) 6.01mm EFL (EFL 2) 10.4269mm ImgH 6.428mm Second interval (d2) 2.0311mm

[0167] Table 4 shows lens information when the camera module operates in a second mode as a near mode. Specifically, Table 4 shows the radius of curvature, thickness of each lens, center spacing between lenses 110, 120, 130, 140, and 150 in near mode, as well as the refractive index, Abbe number, and effective diameter (aperture). Table 5 shows data regarding the size of the image sensor 300, TTL, BFL (BFL2), EFL (EFL2), field of view (FOV), and F-number when operating in near mode. Referring to Tables 4 and 5, the camera module can obtain information about a subject located at close range by operating in near mode. When the subject is at close range, the drive member can control the position of at least one of the multiple lens groups for operation in near mode. For example, when the camera module operates in near mode, the first lens group G1 can be fixed, and the second lens group G2 can be moved by the driving force of the drive member. Specifically, in near mode, the second lens group G2 can be positioned at a second position. In this scenario, when the initial position of the second lens group G2 is not the second position corresponding to the near mode, the second lens group G2 can be moved to the second position. That is, the second lens group G2 can be positioned in a region separated from the first lens group G1 by a second interval d2 via the driving force of the driving member. Here, the second interval d2 can refer to the center interval between the third lens 130 and the fourth lens 140. Alternatively, when the initial position of the second lens group G2 is the second position, the second lens group G2 can be positioned at the second position without separate movement. Therefore, the second lens group G2 can be positioned in a region separated from the first lens group G1 by a second interval d2. Compared to the infinity mode, when the imaging device module operates in the near mode, the interval between the first lens group G1 and the second lens group G2, such as the interval between the third lens 130 and the fourth lens 140, can vary. When the camera module operates in near mode, the optical system 1000 may have a second TTL (TTL2) defined as the TTL value at the second position, a second BFL (BFL2) defined as the BFL value, and a second EFL (EFL2) defined as the effective focal length (EFL). The second TTL (TTL2) may be the same as the first TTL (TTL1). That is, since the first lens group G1 is fixed, the first TTL (TTL1) and the second TTL (TTL2) may be the same. Furthermore, the second EFL may be smaller than the first EFL, and the second BFL (BFL2) may be smaller than the first BFL (BFL1). Specifically, since the first lens group G1 has positive (+) refractive power and the second lens group G2 has negative (-) refractive power, the second BFL (BFL2) may be smaller than the first BFL (BFL1).

[0168] Reference Figure 8The optical system 1000 can possess excellent aberration characteristics. In detail, Figure 8 This is a graph showing the aberration characteristics of the optical system 1000 operating in the second mode (near mode), specifically a graph measuring spherical aberration (longitudinal spherical aberration), astigmatism, and distortion aberration from left to right. Figure 8 In the image, the X-axis can indicate focal length (mm) or distortion (%), and the Y-axis can indicate the image height. Furthermore, the spherical aberration graph is a graph of light in the wavelength bands of approximately 435 nm, approximately 486 nm, approximately 546 nm, approximately 587 nm, and approximately 656 nm, and the astigmatism and distortion aberration graph is a graph of light in the wavelength band of 546 nm. The imaging device module according to the embodiment can be switched to an infinity mode or a near mode depending on the distance from the subject. In this case, the second lens group G2 can move to a first position or a second position depending on the distance from the subject. For example, the second lens group G2 can move from the first position to the second position, or from the second position to the first position. The moving distance md1 of the second lens group G2 can be less than the total TTL value of the optical system 1000, such as the first TTL TTL1 and the second TTL TTL2. Furthermore, the moving distance md1 of the second lens group G2 can be less than the first BFL BFL1 and the second BFL BFL2. The movement distance md1 of the second lens group G2 can be less than the diagonal length ImgH of the image sensor 300, and can be less than the effective diameter (CA_Sa) of the lens with the largest effective diameter among the multiple lens surfaces. For example, the movement distance md1 of the second lens group G2 can be about 1 mm or greater. More specifically, the movement distance of the second lens group G2 can be about 1.6 mm. Here, the movement distance md1 can refer to the difference between the second interval d2 and the first interval d1.

[0169] [Table 6]

[0170] Implementation md1 (distance moved by the second lens group) 1.6mm f1 11.6076 f2 -5.3452 f3 3.6086 f4 -3.9440 f5 13.1671 f_1 6.59 f_2 -6.78 ImgH 6.428mm EPD 5.38mm F-number 3.1784 Curvature in the first mode 0 Curvature in the second mode 0.148

[0171] [Table 7]

[0172]

[0173]

[0174] Table 6 relates to the terms of the above formulas in the optical system and imaging module according to the embodiment; the moving distance md1 of the movable lens group (second lens group G2); the focal lengths f1, f2, f3, f4, f5 of the first to fifth lenses 110, 120, 130, 140, 150; the focal lengths of the first lens group and the second lens groups G1, G2; and the diameter, curvature, etc. of the entrance pupil (EPD). Table 7 shows the result values ​​of formulas 1 to 30 of the optical system 1000 according to the embodiment. Referring to Table 7, it can be seen that the optical system 1000 and the imaging device module according to the embodiment satisfy at least one or two or more of formulas 1 to 30. In detail, it can be seen that the optical system 1000 and the imaging module according to the embodiment satisfy all the formulas 1 to 30 above. Therefore, the embodiment can have improved optical properties and can prevent or minimize the degradation of peripheral image quality. Furthermore, the implementation can provide autofocus (AF) functionality for subjects located at various distances by using an optical system 1000 with a set shape, focal length, spacing, etc. Specifically, the implementation can provide autofocus (AF) functionality for subjects located at infinity or near distances by using a camera module. In the implementation, the effective focal length (EFL) can be controlled by moving at least one lens group, and the movement distance of the moving lens group is minimized. For example, according to the implementation, the movement distance md1 of the second lens group G2 can be 1.6 mm, which is the difference between the second distance d2 and the first distance d1. That is, the second lens group G2 can move 1.6 mm from infinity to a near distance (30 mm) focal point. Furthermore, the second lens group can move approximately 0.08 mm from infinity to another near distance (70 mm) focal point. On the other hand, in a comparative example (not shown) where the first and second lens groups are moved to one lens group, the movement can be approximately 16 mm from infinity to a near distance (30 mm) focal point, and approximately 0.43 mm from infinity to another near distance (70 mm) focal point. Therefore, when the focus changes from infinity to the near field, the optical system 1000 according to the embodiment can significantly reduce the movement distance of the lens group compared to the comparative example, thereby minimizing the power consumption required to move the lens group. Furthermore, by minimizing the movement distance of the lens group, the amount of curvature resulting from the movement distance of the lens group can be minimized. Therefore, the optical system according to the embodiment can have improved electrical and optical properties. In the range from infinity to the near field, regardless of the distance from the subject, the embodiment can have a constant TTL value. Therefore, the optical system 1000 and the imaging device module including the optical system can be configured with a thinner structure. At least one lens in the optical system 1000 can have a non-circular shape, such as a D-shaped cut.Therefore, compared to optical systems with only a circular shape, optical system 1000 can be implemented in a smaller size, has improved optical performance, and can be arranged more compactly. Optical system 1000 may include multiple lenses and light path changing components (not shown). Therefore, optical system 1000 can be applied to folding imaging devices that can have a thinner profile, and the device including the imaging device can be manufactured to have a thin profile.

[0175] Figure 9 This is a configuration diagram illustrating that the optical system according to the embodiment also includes a third lens group.

[0176] Reference Figure 9 In addition to the first lens group G1 and the second lens group G2 described above, the optical system 1000 according to the embodiment may also include a third lens group G3. The third lens group G3 may have positive (+) refractive power or negative (-) refractive power. The third lens group G3 may include at least one lens. When the third lens group G3 includes multiple lenses, the center spacing between the multiple lenses included in the third lens group G3 may be constant and will not change according to the operating mode. The third lens group G3 may be positioned at a predetermined location. For example, as... Figure 9 As shown in (a), the third lens group G3 can be disposed between the second lens group G2 and the image sensor 300. In this case, the third lens group G3 can be fixed like the first lens group G1, and the second lens group G2 can be disposed as movable.

[0177] In this case, at least one lens included in the third lens group G3 can have a set effective diameter (aperture). Specifically, the effective diameter of at least one lens surface among the plurality of lens surfaces included in the third lens group G3 can be larger than the effective diameter of the object-side surface of the lens closest to the object among the lenses included in the first to third lens groups G1, G2, G3. For example... Figure 9 As shown in (b), the third lens group G3 can be disposed between the object and the first lens group G1. In this case, the first lens group G1 can be fixed like the first lens group G1, or it can be disposed as movable like the second lens group G2. In this case, at least one lens included in the third lens group G3 can have a set effective diameter (aperture). Specifically, the optical system 1000 can include a lens surface having an effective diameter larger than the object-side surface of the lens in the third lens group G3 closest to the object.

[0178] Figure 10 This diagram illustrates the application of a camera device module according to an embodiment to a mobile terminal.

[0179] Reference Figure 10 The mobile terminal 1 may include a camera module 10 disposed on the rear side. The camera module 10 may include an image capture function. Furthermore, the camera module 10 may include at least one of an autofocus function, a zoom function, and an OIS function. The camera module 10 can process image frames of still video images or moving images acquired by the image sensor 300 in imaging mode or video call mode. The processed image frames may be displayed on a display unit (not shown) of the mobile terminal 1 and may be stored in a memory (not shown). Additionally, although not shown in the figure, the camera module may also be disposed on the front of the mobile terminal 1. For example, the camera module 10 may include a first camera module 10A and a second camera module 10B. In this case, at least one of the first camera module 10A and the second camera module 10B may include the aforementioned optical system 1000. Therefore, the camera module 10 may have improved optical characteristics and can provide autofocus (AF) functionality for subjects located at short distances from infinity to 40mm or less. Furthermore, when at least one lens group moves to provide the above functions, the optical system 1000 can minimize the amount of movement of the lens group, thereby operating with low power and minimizing the amount of curvature caused by the movement. Additionally, the camera module can be arranged more compactly using the optical system 1000, which has a slim structure.

[0180] Mobile terminal 1 may also include an autofocus device 31. The autofocus device 31 may include an autofocus function using a laser. The autofocus device 31 may be primarily used in situations where the autofocus function of the image from camera module 10 deteriorates (e.g., at a distance of 10m or less or in a dark environment). The autofocus device 31 may include a light-emitting unit and a light-receiving unit. The light-emitting unit includes a vertical-cavity surface-emitting laser (VCSEL) semiconductor device, and the light-receiving unit is, for example, a photodiode that converts light energy into electrical energy. Mobile terminal 1 may also include a flash module 33. The flash module 33 may include a light-emitting device that emits light therein. The flash module 33 may be operated via camera operation of the mobile terminal or by user control.

[0181] The features, structures, effects, etc., described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to one embodiment. Furthermore, the features, structures, effects, etc., shown in each embodiment can be combined or modified by those skilled in the art for other embodiments. Therefore, anything related to such combinations and modifications should be interpreted as being included within the scope of the present invention. Moreover, although embodiments have been described above, these embodiments are merely examples and do not limit the present invention, and the above description is provided to those skilled in the art without departing from the essential characteristics of these embodiments. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be implemented by modification. 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. An optical system comprising a first lens group and a second lens group arranged sequentially along the optical axis from the object side to the sensor side. in, The focal length signs of the first lens group and the second lens group are opposite to each other. The optical system satisfies the equation: -1.5 < f_2 / f_1 < 0 Where f_1 is the focal length of the first lens group, and f_2 is the focal length of the second lens group. The effective diameter of the lenses included in the first lens group and the second lens group is smaller than the diagonal length of the image sensor. In this configuration, one of the first lens group and the second lens group is movable in the direction of the optical axis. The first lens group consists of a first lens to a third lens arranged sequentially along the optical axis from the object side to the sensor side, and the second lens group consists of a fourth lens and a fifth lens arranged sequentially along the optical axis from the object side to the sensor side. The object-side surface of the first lens has a convex shape. The first lens has positive refractive power, the second lens has negative refractive power, and the third lens has positive refractive power. The fourth lens has negative refractive power, and the fifth lens has positive refractive power. The center thickness of the first lens is L1_CT. Wherein, the center thickness of the second lens is L2_CT, and The optical system satisfies the following equation: 1 < L1_CT / L2_CT < 10.

2. The optical system according to claim 1, wherein, The sensing side surface of the fifth lens has a convex shape.

3. The optical system according to claim 1, wherein, The sensor-side surface of the first lens has a convex shape.

4. The optical system according to claim 2, wherein, The object-side surface of the fourth lens, which is located closest to the object side in the second lens group, has a concave shape.

5. The optical system according to any one of claims 1 to 4, wherein, The first lens group and the second lens group satisfy Equation 1: 1 < L_G1 / L_G2 < 4 In Equation 1, L_G1 refers to the distance along the optical axis from the vertex of the object-side surface of the lens closest to the object in the first lens group to the vertex of the sensor-side surface of the lens closest to the image sensor, and L_G2 refers to the distance along the optical axis from the vertex of the object-side surface of the lens closest to the object in the second lens group to the vertex of the sensor-side surface of the lens closest to the image sensor.

6. The optical system according to any one of claims 1 to 4, wherein, The second lens group satisfies the following equation 2: 4 < TTL / L_G2 < 7 In Equation 2, L_G2 refers to the distance along the optical axis from the vertex of the object-side surface of the lens closest to the object among the lenses included in the second lens group to the vertex of the sensor-side surface of the lens closest to the image sensor, and the total track length TTL refers to the distance along the optical axis from the vertex of the object-side surface of the lens closest to the object among the plurality of lenses included in the first lens group and the second lens group to the image sensor.

7. The optical system according to any one of claims 1 to 4, wherein, The first lens has a non-circular shape.

8. The optical system according to any one of claims 1 to 4, wherein, The center distance between the first lens and the second lens is T12, and The optical system satisfies the following equation: 1 < T12 / L1_CT < 2.

5.

9. A camera device module including an optical system and a driving component, in, The optical system includes the optical system according to any one of claims 1 to 4, and The driving component controls the position of the second lens group.

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