Optical system and camera module comprising same

Abstract

An optical system provided in an embodiment of the invention may comprise first to sixth lenses arranged along an optical axis from an object toward a sensor side. The first lens may have negative (-) refractive power on the optical axis. The object-side surface of the first lens may have a convex shape on the optical axis. The object-side surface of the second lens may have a convex shape on the optical axis. The optical axis interval between the second lens and the third lens may be greater than the optical axis interval between the first lens and the second lens.

Description

Optical system and camera module including the same

[0001] The embodiment relates to an optical system and a camera module for improved optical performance.

[0002] Camera modules perform the function of capturing objects and storing them as images or videos, and are installed in various applications. In particular, camera modules are manufactured in an ultra-small size and are applied to portable devices such as smartphones, tablet PCs, and laptops, as well as drones and vehicles, providing various 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. At this time, the camera module can perform an autofocus (AF) function that automatically adjusts the distance between the image sensor and the imaging lens to align the focal length of the lens, and can perform a zooming function that increases or decreases the magnification of a distant object through a zoom lens. In addition, the camera module adopts image stabilization (IS) technology to compensate for or prevent shaking of the image caused by camera movement due to an unstable fixed device or the user's movements.

[0003] The most crucial element for these camera modules to capture images is the imaging lens that forms the image. Recently, interest in high resolution has been increasing, and research is being conducted on optical systems that incorporate multiple lenses to achieve this. For example, research is being conducted using multiple imaging lenses with positive or negative refractive power to achieve high resolution. However, the inclusion of multiple lenses presents challenges in achieving superior optical and aberration characteristics. Furthermore, the inclusion of multiple lenses can increase the overall length and height due to the thickness, spacing, and size of the lenses, thereby increasing the overall size of the module. Furthermore, the size of image sensors is increasing to achieve high resolution and high image quality. However, as the image sensor size increases, the total track length (TTL) of the optical system comprising multiple lenses also increases, leading to an increase in the thickness of cameras, mobile devices, and other devices that incorporate the optical system. Therefore, a new optical system capable of solving the aforementioned problems is required.

[0004] The present invention provides an optical system with improved optical characteristics. The present invention provides an optical system comprising a mixture of glass and plastic lenses, and a camera module having the same. The present invention provides an optical system capable of protecting plastic lenses by positioning a glass lens on the object side, and a camera module having the same. The present invention provides an optical system having excellent optical performance at the center and periphery of the field of view. The present invention provides an optical system capable of reducing deviations in optical characteristics due to thermal changes.

[0005] An optical system according to an embodiment includes first to sixth lenses arranged along an optical axis from an object toward a sensor side, wherein the first lens has a negative (-) refractive power on the optical axis, an object-side surface of the first lens has a convex shape on the optical axis, an object-side surface of the second lens has a convex shape on the optical axis, and an optical axis distance between the second lens and the third lens may be greater than an optical axis distance between the first lens and the second lens.

[0006] According to an embodiment of the invention, the central thickness of the sixth lens may be the thickest among the central thicknesses of the first to sixth lenses. The third lens may have positive refractive power on the optical axis. The central thickness of the second lens may be thicker than the central thickness of the first lens. The refractive index of the third lens may be the largest among the refractive indices of the first to sixth lenses. At least two of the first to sixth lenses may be made of glass, and the central thickness of the first lens may be smaller than the central thickness of a lens arranged between the lenses made of glass. The first lens and the third lens may be made of glass, and the second, fourth, fifth, and sixth lenses may be made of plastic.

[0007] According to an embodiment of the invention, the second and third lenses may have a meniscus shape convex toward the object on the optical axis. The central thickness of the fifth lens may be the thinnest among the central thicknesses of the first to sixth lenses. The effective length of the object-side surface and the sensor-side surface of each of the third to sixth lenses may be less than the diagonal length of the image sensor.

[0008] An optical system according to an embodiment of the invention comprises a first lens group having first and second lenses arranged along an optical axis from an object toward a sensor side; a second lens group having third to sixth lenses arranged on a sensor side of the first lens group and aligned along an optical axis from the object toward the sensor side; and an aperture arranged on a periphery between the third lens and the fourth lens, wherein the power of the first lens group has a negative (-) value, and an optical axis distance between the second lens and the third lens may be greater than an optical axis distance between the first lens and the second lens.

[0009] According to an embodiment of the invention, the first lens may have a negative (-) refractive power and a largest focal length among the first to sixth lenses, and the sixth lens may have a positive (+) refractive power. The first lens may have a meniscus shape convex toward the object on the optical axis, and the effective length of the first lens may be the largest among the effective lengths of the first to sixth lenses.

[0010] According to an embodiment of the invention, the optical axis spacing between the second and third lenses is CG2, the center thickness of the sixth lens is CT6, and the mathematical expression: 1 < CG2 / CT6 < 3 can be satisfied. The optical axis spacing between the second and third lenses is CG2, and the optical axis spacing between the first and second lenses is CG1, and the mathematical expression: 5 < GG2 / CG1 < 25 can be satisfied.

[0011] According to an embodiment of the invention, the optical axis distance from the sensor side of the sixth lens to the upper surface of the image sensor is BFL, the center thickness of the sixth lens is CT6, and the mathematical expression: 0.5 < BFL / CT6 < 1 can be satisfied. The maximum among the center thicknesses of the first to sixth lenses is CT_Max, and the maximum among the optical axis intervals between adjacent lenses is CG_Max, and the mathematical expression: 0.5 < CT_Max / CG_Max < 1 can be satisfied.

[0012] According to an embodiment of the invention, one of the lenses of the first lens group may include a glass material, and at least one of the lenses of the second lens group may be a glass material. The third lens may be a glass lens and may have a highest refractive index among the refractive indices of the first to sixth lenses. The power of the second lens group may have a positive (+) value, and the focal lengths of the third, fourth, fifth, and sixth lenses may be F3, F4, F5, and F6, and the average of the focal lengths of the third, fourth, fifth, and sixth lenses may satisfy the mathematical formula: 1 < Aver( |F3|+ |F4|+ |F5|+ |F6|) < 6.

[0013] In an embodiment of the invention, in the lenses of an optical system for a mobile object, a glass lens is arranged on the object side of a plastic lens adjacent to the object, thereby having the effect of preventing cracking or yellowing caused by ultraviolet rays. In addition, by arranging a plastic lens and a glass lens within the optical system, price competitiveness can be increased. In an embodiment of the invention, the glass lens closest to the object can be made of a material with low ultraviolet transmittance, thereby preventing cracking or yellowing of the plastic lens. An optical system and a camera module according to the embodiment can have improved optical characteristics. Specifically, the optical system can have improved aberration characteristics and resolution due to the surface shape, refractive power, thickness, and spacing between adjacent lenses of a plurality of lenses. An optical system and a camera module according to the embodiment can have improved distortion and aberration control characteristics, and can have good optical performance at the center and periphery of the field of view (FOV). In addition, the reliability of an optical system and a camera module for a vehicle can be improved.

[0014] FIG. 1 is a configuration diagram of an optical system and a camera module according to a first embodiment of the invention.

[0015] Figure 2 is a table showing lens data of the optical system of Figure 1.

[0016] Fig. 3 is an example of the aspherical coefficients of the lenses of the optical system of Fig. 1.

[0017] Fig. 4 is a graph showing data of the diffraction MTF (Modulation Transfer Function) of the optical system of Fig. 1.

[0018] Fig. 5 is a graph showing the aberration characteristics of the optical system of Fig. 1.

[0019] Fig. 6 is a table showing lens data according to a second embodiment of the optical system of Fig. 1.

[0020] Fig. 7 is an example of the aspherical coefficients of the lenses of Fig. 6.

[0021] Fig. 8 is a graph showing the diffraction MTF (Modulation Transfer Function) data of an optical system having the lens data of Fig. 6.

[0022] Fig. 9 is a graph showing the aberration characteristics of an optical system having the lens data of Fig. 6.

[0023] Fig. 10 is a table showing lens data according to a third embodiment of the optical system of Fig. 1.

[0024] Fig. 11 is an example of the aspherical coefficients of the lenses of Fig. 10.

[0025] Fig. 12 is a graph showing the diffraction MTF data of an optical system having the lens data of Fig. 10.

[0026] Fig. 13 is a graph showing the aberration characteristics of an optical system having the lens data of Fig. 10.

[0027] Fig. 14 is a graph comparing distortion characteristics according to embodiments of the invention.

[0028] FIG. 15 is a perspective view of a mobile body having a camera module according to an embodiment of the invention.

[0029] Fig. 16 is a perspective view of a mobile terminal to which a camera module according to an embodiment of the invention is applied.

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. The technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and one or more of the components between the embodiments can be selectively combined or substituted within the scope of the technical idea of ​​the present invention. In addition, terms (including technical and scientific terms) used in the embodiments of the present invention can be interpreted as having a meaning that can be generally understood by a person having ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, can be interpreted in consideration of the contextual meaning of the related technology.

[0031] The terminology used in the embodiments of the present invention is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular may also include the plural unless specifically stated in the phrase, and when it is described as “A and (or at least one (or more) of B, C)”, it may include one or more of all combinations that can be combined with A, B, and C. In addition, when describing components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the components from other components, and are not limited by the nature, order, or sequence of the components. In addition, when it is described that a component is “connected,” “coupled,” or “connected” to another component, it may include not only cases where the component is directly connected, coupled, or connected to the other component, but also cases where the component is “connected,” “coupled,” or “connected” due to another component between the component and the other component. Additionally, when it is described as being formed or arranged "above or below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when it is expressed as "above" or "below", it can include the meaning of a downward direction as well as an upward direction based on one component.

[0032] In the description of the invention, the "object-side surface" may mean a surface of a lens facing the object side based on the optical axis (OA), and the "sensor-side surface" may mean a surface of a lens facing the imaging surface (image sensor) based on the optical axis. A convex surface of the lens may mean a convex shape in the optical axis or the paraxial region, and a concave surface of the lens may mean a concave shape in the optical axis or the paraxial region. The radius of curvature, center thickness, and gap between lenses described in the table for lens data mean values ​​in the optical axis, and the unit is mm. The vertical direction may mean a direction perpendicular to the optical axis, and the end of the lens or lens surface may mean the end of the effective area of ​​the lens through which incident light passes. The effective length of the lens surface may have a measurement error of up to ±0.4 mm depending on the measurement method, etc. The above-mentioned near-axis region refers to a very narrow region near the optical axis, and is a region where the distance a light ray falls from the optical axis (OA) is almost 0. Hereinafter, the concave or convex shape of the lens surface is described as the optical axis, and may also include the near-axis region.

[0033]

[0034] FIG. 1 is a configuration diagram of an optical system and a camera module according to embodiments of the invention.

[0035] Referring to FIG. 1, an optical system (1000) or a camera module may include a lens unit (100) having a plurality of lenses. The lenses of the lens unit (100) may be divided into a plurality of lens groups (LG1, LG2). For example, the lens unit (100) may include a first lens group (LG1) arranged on the object side and a second lens group (LG2) arranged on the sensor side of the first lens group (LG1). Each of the first and second lens groups (LG1, LG2) includes at least one lens, and may include at least two lenses, for example. The number of lenses of the second lens group (LG2) may be greater than the number of lenses of the first lens group (LG1), and may be, for example, in a range of 1.5 to 2.5 times the number of lenses of the first lens group (LG1).

[0036] The first lens group (LG1) may include two or fewer lenses. The first lens group (LG1) may, for example, include two lenses. The first lens group (LG1) may include a glass lens and a plastic lens, and the glass lens may be arranged on the object side of the plastic lens. Accordingly, the glass lens of the first lens group (LG1) may block external exposure of the plastic lens and protect it from external heat or impact. That is, the object-side first lens (101) of the first lens group (LG1) may be made of a glass material having low UV transmittance, thereby preventing cracks or yellowing that may occur in plastic lenses. The second lens group (LG2) may include three or more and five or fewer lenses. The second lens group (LG2) may include plastic lenses and at least one glass lens. Among the lenses of the second lens group (LG2), the lens closest to the first lens group (LG1) may be made of glass and may protect the adjacent lenses made of plastic. The second lens group (LG2) may include, for example, four lenses.

[0037] The optical system (1000) may include 8 or fewer or 7 or fewer lenses. The first lens group (LG1) may include the first lens (101) and the second lens (102), and the second lens group (LG2) may include the third to sixth lenses (103-106). The number of glass lenses in the optical system (1000) may be smaller than the number of plastic lenses.

[0038] The total track length (TTL) of the optical system (1000) may be 1.5 times or more the diagonal length of the image sensor (190), for example, in the range of 1.5 to 3 times or 2 to 3 times. The TTL is the distance from the object-side surface of the first lens (101) closest to the object to the image surface of the image sensor (190) on the optical axis (OA). The ImgH is half the diagonal length of the effective area of ​​the image sensor (190). The first lens group (LG1) may have negative (-) refractive power (or power). The second lens group (LG2) may have refractive power having a sign opposite to the refractive power of the first lens group (LG1). The second lens group (LG2) may have positive (+) refractive power or positive power. The first lens group (LG1) and the second lens group (LG2) have different focal lengths, and thus can have good optical performance in the center and periphery of the field of view (FOV). The refractive power is power and is the reciprocal of the focal length. When the focal length is expressed as an absolute value, the focal length of the first lens group (LG1) may be smaller than the focal length of the second lens group (LG2). The focal length of the second lens group (LG2) may be less than 5 times the focal length of the first lens group (LG1), for example, 4 times or less or 2 times or less. Accordingly, the optical system (1000) according to the embodiment can have improved aberration control characteristics such as chromatic aberration and distortion aberration by controlling the refractive power and focal length of each lens group (LG1, LG2), and can have good optical performance in the center and periphery of the field of view (FOV).

[0039]

[0040] The first lens group (LG1) may include lenses having a meniscus shape convex toward an object. At least one or both of the object-side and sensor-side surfaces of the lenses of the first lens group (LG1) may be provided without a critical point from the optical axis to the end of the effective area. Accordingly, since the lenses of the first lens group (LG1) do not have a critical point, the effective length of the lenses of the second lens group (LG2), i.e., the effective length, may not be significantly increased. In the first and second lens groups (LG1, LG2), two lens surfaces facing each other, for example, the sensor-side surface of the first lens group (LG1) may be concave on the optical axis, and the object-side surface of the second lens group (LG2) may be convex on the optical axis. The two lenses facing each other in the first and second lens groups (LG1, LG2) may be made of different materials, have a central thickness of 2 mm or less, and have refractive powers of opposite signs. The first lens group (LG1) above refracts light incident through the object side to gather it, and the second lens group (LG2) can refract light emitted through the first lens group (LG1) to the periphery of the image sensor (190).

[0041] Among the lenses of the first and second lens groups (LG1, LG2), the lens having the maximum effective length may be arranged in the first lens group (LG1), and the lens having the minimum effective length may be arranged in the second lens group (LG2). Among the lenses of the first and second lens groups (LG1, LG2), the lens having the largest refractive index may be arranged in the second lens group (LG2). Among the lenses of the first and second lens groups (LG1, LG2), the lens having the thickest central thickness may be arranged in the second lens group (LG2). When the object-side surface or the sensor-side surface of the lens is circular or non-circular, it may be defined as the effective length or effective length, and represents the maximum effective length in the direction orthogonal to the optical axis.

[0042] The first lens group (LG1) may include lenses made of glass and lenses made of plastic. The first lens group (LG1) may include spherical lenses and aspherical lenses. The second lens group (LG2) may include lenses made of glass and lenses made of plastic, and the number of aspherical lenses may be greater than the number of spherical lenses. The spherical lenses have an object-side surface and a sensor-side surface that are spherical on the optical axis, and the aspherical lenses have an object-side surface and a sensor-side surface that are aspherical on the optical axis. The aspherical surface may include a free-form surface. At least one of the lenses of the first lens group (LG1) and at least one of the lenses of the second lens group (LG2) may be made of glass. Since the lens unit (100) includes at least one glass lens, thermal compensation can be satisfied and deterioration of optical characteristics due to temperature change can be prevented. Among at least three lenses adjacent to an object within the optical system (1000), at least two can be arranged as lenses made of glass, thereby eliminating thermal compensation in an area adjacent to the object.

[0043] The first lens group (LG1) and the second lens group (LG2) may have a set gap on the optical axis (OA). The optical axis gap (CG2) between the first lens group (LG1) and the second lens group (LG2) on the optical axis (OA) is a separation distance on the optical axis (OA), and may be an optical axis gap between a sensor-side surface of a lens closest to the sensor side among the lenses in the first lens group (LG1) and an object-side surface of a lens closest to the object side among the lenses in the second lens group (LG2). The optical axis gap (CG2) between the first lens group (LG1) and the second lens group (LG2) may be greater than the center thicknesses (CT1, CT2) of the first and second lenses (101, 102) of the first lens group (LG1) and greater than the center thickness (CT3) of the object-side third lens (103) of the second lens group (LG2).

[0044] The effective length of a lens adjacent to an object within the first lens group (LG1) may be greater than the average effective length of the second lens group (LG2), and may be the maximum within the lens unit (100). The lens having the maximum effective length within the optical system (1000) is a glass lens. The lens having the minimum effective length within the optical system (1000) is a plastic lens. The size of the effective length is an average value of the effective length of the object-side surface and the effective length of the sensor-side surface of each lens. The lens having the maximum effective length within the optical system is the first lens (101). Accordingly, the optical system (1000) can increase the amount of incident light, have good optical performance at the center and periphery of the field of view (FOV), and improve thermal compensation, chromatic aberration, and distortion aberration.

[0045]

[0046] When the plurality of lenses in the optical system (1000) are a mixture of plastic lenses and glass lenses, the price can be lowered compared to a lens configuration made of glass materials, and the aspherical lenses can facilitate light path control. However, plastic lenses can expand or contract with temperature changes, which can affect the optical characteristics of the lenses. In addition, plastic lenses are vulnerable to high-temperature environments and their optical performance can be affected by ultraviolet rays. For example, plastic lenses can be damaged by cracks or yellowing of the material caused by ultraviolet (UV) rays. Such cracks or yellowing in the plastic lens can cause changes in the refractive index and transmittance of the lens, which can affect the optical performance. Therefore, when applying plastic lenses, the glass lens can be placed closer to the object side than the plastic lens to block ultraviolet rays, and two or more glass lenses can suppress the deterioration of optical performance due to thermal changes.

[0047] Among the lenses of the first lens group (LG1), the lens closest to the object may have negative (-) refractive power, and among the lenses of the second lens group (LG2), the lens closest to the image sensor (190), i.e., the last lens, may have positive (+) refractive power. The number of lenses having positive (+) refractive power in the optical system (1000) may be equal to the number of lenses having negative (-) refractive power. In the second lens group (LG2), the number of lenses having positive (+) refractive power may be greater than the number of lenses having negative (-) refractive power. Accordingly, the resolution can be improved by utilizing the refractive power and positive and negative focal lengths of each lens.

[0048] Each of the plurality of lenses may include an effective area and an ineffective area. The effective area may be an area through which light incident on each of the lenses passes. That is, the effective area may be an area having an effective diameter or effective length through which the incident light is refracted to implement optical characteristics. The ineffective area may be arranged around the periphery of the effective area. The end of the effective area may be defined as an edge or an end. The ineffective area may be an area through which effective light is not incident on the plurality of lenses. That is, the ineffective area may be an area unrelated to the optical characteristics. In addition, the end of the ineffective area may be an area fixed to a barrel (not shown) that accommodates the lens.

[0049]

[0050] The optical system (1000) 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 sequentially passes through the plurality of lenses (100). The image sensor (190) may be any one of a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), a CPD, and a CID, and may include an element that may detect incident light. The image sensor (190) may be an RGB (Red, Green, Blue) sensor for obtaining a color image. In addition, when the image sensors (190) are arranged in plurality, the image sensors (190) may include an RGB image sensor and a black and white image sensor. The diagonal length of the image sensor (190) may be greater than 6 mm, for example, greater than 6 mm and less than 20 mm. Preferably, the diagonal length of the image sensor (190) may be smaller than TTL. In addition, the diagonal length of the image sensor (190) may be smaller than the overall focal length (EFL) of the optical system (1000).

[0051] The optical system (1000) may include an optical filter (192) disposed between the lens unit (100) and the image sensor (190). The optical filter (192) may be disposed between the second lens group (LG2) and the image sensor (190). The optical filter (192) may be disposed between the lens closest to the sensor side among the plurality of lenses (100) and the image sensor (190). For example, when the optical system (100) has six lenses, the optical filter (192) may be disposed between the sixth lens (106), which is the last lens, and the image sensor (190). In FIG. 2, IR represents an optical filter. The optical filter (192) may filter light corresponding to a specific wavelength range among light passing through the lens unit (100). The optical filter (192) may be an infrared (IR) blocking filter that blocks infrared rays or an ultraviolet (UV) blocking filter that blocks ultraviolet rays, but the embodiment is not limited thereto. Since the optical filter (192) is positioned closer to the last lens (106) than to the image sensor (190), light loss can be reduced and an increase in the size of the image sensor (190) can be prevented.

[0052] When the optical filter (192) includes an infrared filter, it can block radiant heat emitted from external light from being transmitted to the image sensor (190). In addition, the optical filter (192) can transmit visible light and reflect infrared light. As another example, a cover glass can be further disposed between the optical filter (192) and the image sensor (190). A cover glass (not shown) can be included between the optical filter (192) and the image sensor (190). The cover glass can protect the image sensor (190). The camera module can be a camera for capturing RGB images or a camera for capturing RGB images and infrared images.

[0053]

[0054] The optical system (1000) according to the embodiment may include an aperture stop (ST). The aperture (ST) may be a stopper that controls the amount of light incident on the optical system (1000). For example, the aperture (ST) may be arranged around the sensor-side surface of the third lens (103) or around the object-side surface of the fourth lens (104). The aperture (ST) may be arranged closer to the fourth lens (104) than to the third lens (103). Alternatively, the object-side surface of the fourth lens (104) may function as an aperture.

[0055] The optical axis distance (SD) from the sensor-side surface of the nth lens in the aperture (ST) may be smaller than the optical axis distance (TD) from the object-side surface of the first lens (101) to the sensor-side surface of the nth lens. The distance relationship among EFL, ImgH, and TTL may vary depending on the position of the aperture (ST). Condition: At least one or all of the conditions of ImgH < SD < TD, and TD < TTL may be satisfied. Here, EFL is the effective focal length of the entire optical system and may be defined as F. Condition: The condition of F < SD < TD < TTL may be satisfied. The field of view (FOV) of the optical system (1000) may be 100 degrees or less, for example, in the range of 30 degrees to 100 degrees, and for example, in the range of 50 to 80 degrees. The F number (F#) of the optical system (1000) may be in the range of 1 to 10, for example, 1.1 ≤ F# ≤ 5, and when it is 3 or less, a bright image may be provided. In addition, the F# may be larger than the entrance pupil size (EPD). Therefore, the optical system (1000) may have a slim size, control incident light, and have improved optical characteristics within the field of view.

[0056] The optical system (1000) according to the embodiment may further include a reflective member (not shown) for changing the path of light. The reflective member may be implemented as a prism that reflects incident light of the first lens group (LG1) toward the lenses.

[0057]

[0058] Hereinafter, optical systems according to embodiments will be described in detail. FIGS. 1 to 5 are drawings explaining the optical system of the first embodiment. Referring to FIGS. 1 and 2, in the first embodiment of the invention, the lens unit (100) may include a first lens (101) to a sixth lens (106). The first to sixth lenses (101-106) may be sequentially aligned along the optical axis (OA). Light corresponding to information of an object may pass through the first lens (101) to the sixth lens (106) and the optical filter (192) and be incident on the image sensor (190).

[0059] The optical axis distance (CG2) between the second lens (102) and the third lens (103) may be the optical axis spacing between the first and second lens groups (LG1, LG2). The number of lenses having a meniscus shape convex from the optical axis toward the object among the first to sixth lenses (101-106) may be two or more. The first lens (101) may have positive (+) or negative (-) refractive power on the optical axis (OA), and preferably positive (+) refractive power. The first lens (101) may include a plastic or glass material. For example, the first lens (101) is made of glass. Since the first lens (101) is arranged as a glass material, it is possible to prevent the optical characteristics of the lenses from being deteriorated due to heat at a location adjacent to the object. The first surface (S1) on the object side of the first lens (101) on the optical axis (OA) may have a convex shape, and the second surface (S2) on the sensor side may have a concave shape. That is, the first lens (101) may have a meniscus shape that is convex toward the object side on the optical axis (OA). Since the first lens (101) has a meniscus shape that is convex toward the object side, the amount of incident light may be improved. At least one or both of the first surface (S1) and the second surface (S2) may be spherical. Alternatively, the first lens (101) may have a convex shape on both sides. Alternatively, the first lens (101) may have a concave shape on both sides.

[0060]

[0061] The second lens (102) may have positive (+) or negative (-) refractive power on the optical axis (OA). The second lens (102) may have negative (-) refractive power. The second lens (102) may include a plastic or glass material. For example, the second lens (102) may be provided as a plastic material. The object-side third surface (S3) of the second lens (102) on the optical axis (OA) may have a convex shape, and the sensor-side fourth surface (S4) may have a concave shape. That is, the second lens (102) may have a meniscus shape that is convex toward the object side on the optical axis (OA). Alternatively, the third surface (S3) on the optical axis (OA) may have a convex shape, and the fourth surface (S4) may have a convex shape. In contrast, both the third and fourth surfaces (S3, S4) may have a concave shape. The second lens (102) made of the plastic material has a center thickness (CT2) that is thicker than the center thickness (CT1) of the first lens (101) made of the glass material, and has a convex meniscus shape, so that an increase in the effective length of the third lens (103) can be suppressed. The focal length (absolute value) of the second lens (102) may be the largest within the lens unit (100), and can correct spherical aberration occurring in the first lens (101).

[0062] At least one or both of the third surface (S3) and the fourth surface (S4) of the second lens (102) may be aspherical. The aspherical coefficients of the third and fourth surfaces (S3, S4) are provided as shown in FIG. 3, where L2 is the second lens (102), L2S1 is the third surface, and L2S2 is the fourth surface. The third and fourth surfaces (S3, S4) of the second lens (102) may be provided without a critical point from the optical axis to the end of the effective area. The critical point may be a point where the slope value of the tangent passing through the lens surface decreases as it increases or a point where it decreases and then increases. The third surface (S3) of the second lens (102) may face the second surface (S2) of the first lens (101). That is, the gap between the first and second lenses (101, 102) can be arranged to be 0.5 mm or less from the center gap to the edge gap between the first and second lenses (101, 102). Accordingly, the loss of light passing through the first and second lenses (101, 102) can be reduced.

[0063] The maximum Sag (Sagittal) value (absolute value) of the sensor-side fourth surface (S4) of the second lens (102) may be greater than the center thickness (CT2) of the second lens (102), and may be the largest among the absolute values ​​of the Sag values ​​of each lens surface of the first to sixth lenses (101-106). Here, the Sag value is the distance in the direction of the optical axis from the center of each lens surface to the lens surface based on a straight line perpendicular to the optical axis (OA), and when the Sag value has a positive value, each lens surface is located closer to the sensor side than the straight line, and when the Sag value has a negative value, each lens surface may be located closer to the object side than the straight line.

[0064]

[0065] The third lens (103) may have positive (+) or negative (-) refractive power on the optical axis (OA), and preferably positive (+) refractive power. The third lens (103) may include a plastic or glass material. For example, the third lens (103) may be made of glass. The object-side fifth surface (S5) of the third lens (103) on the optical axis (OA) may have a convex shape, and the sensor-side sixth surface (S6) may have a concave shape. That is, the third lens (103) may have a meniscus shape that is convex toward the object on the optical axis (OA). Alternatively, the third lens (103) may have a convex shape on both sides. Alternatively, the fifth and sixth surfaces (S5, S6) may both have concave shapes. Alternatively, the third lens (103) may have a convex meniscus shape toward the sensor. At least one or both of the fifth surface (S5) and the sixth surface (S6) of the third lens (103) may be aspherical. The aspherical coefficients of the fifth and sixth surfaces (S5, S6) are provided as shown in FIG. 3, where L3 is the third lens (103), L3S1 is the fifth surface, and L3S2 is the sixth surface.

[0066] The gap between the second and third lenses (102, 103) may gradually decrease from the center between the second and third lenses (102, 103) toward the edge. The center gap (CG2) between the second and third lenses (102, 103) may be greater than the sum of the center thicknesses (CT1, CT2) of the first and second lenses (101, 102). The center gap (CG2) between the second and third lenses (102, 103) may be the largest among the center gaps between the lenses. The center gap (CG2) between the second and third lenses (102, 103) may be greater than the maximum thickness of the lenses, for example, the maximum center thickness.

[0067]

[0068] The fourth lens (104) may have positive (+) or negative (-) refractive power on the optical axis (OA). The fourth lens (104) is the n-2th lens and may have positive (+) refractive power. The fourth lens (104) may include a plastic or glass material. For example, the fourth lens (104) may be provided as a plastic material. The seventh surface (S7) on the object side of the fourth lens (104) on the optical axis (OA) may have a convex shape, and the eighth surface (S8) on the sensor side may have a convex shape. That is, the fourth lens (104) may have a convex shape on both sides on the optical axis (OA). Alternatively, the fourth lens (104) may have a meniscus shape that is convex on the object side. Alternatively, the fourth lens (104) may have a meniscus shape that is convex from the optical axis toward the sensor. Alternatively, the fourth lens (104) may have a concave shape on both sides. At least one or both of the seventh surface (S7) and the eighth surface (S8) may be aspherical, and the aspherical coefficient is provided as in FIG. 3, where L4 is the fourth lens (104), L4S1 is the seventh surface, and L4S2 is the eighth surface. The fourth lens (104) may have a minimum effective length among the lenses. The maximum effective length of the lenses may be more than two times, for example, three times or four times, the minimum effective length. The effective length of the lenses may gradually decrease from the first lens (101) to the fourth lens (104), and may gradually increase from the fourth lens (104) to the sixth lens (106). Since the signs of the refractive powers of the third and fourth lenses (103, 104) are opposite to the signs of the refractive powers of the first and second lenses (101, 102), the chromatic aberration occurring in each lens can be mutually compensated.

[0069]

[0070] The fifth lens (105) may have positive (+) or negative (-) refractive power on the optical axis (OA). The fifth lens (105) is the (n-1)th lens and may have negative refractive power. The fifth lens (105) may include a plastic or glass material. For example, the fifth lens (105) may be provided as a plastic material. The ninth surface (S9) on the object side of the fifth lens (105) on the optical axis (OA) may have a concave shape, and the tenth surface (S10) on the sensor side may have a concave shape. That is, the fifth lens (105) may have a concave shape on both sides on the optical axis (OA). Alternatively, the fifth lens (105) may have a convex meniscus shape toward the sensor side. Alternatively, the fifth lens (105) may have a convex shape on both sides. In contrast, the fifth lens (105) may have a meniscus shape that is convex toward the object on the optical axis (OA). At least one or both of the ninth surface (S9) and the tenth surface (S10) of the fifth lens (105) may be aspherical, and the aspherical coefficient is provided as in FIG. 3, where L5 is the fifth lens (105), L5S1 is the ninth surface, and L5S2 is the tenth surface. At least one or both of the ninth surface (S9) and the tenth surface (S10) of the fifth lens (105) may be provided without a critical point. In addition, the distance between the eighth surface (S8) of the fourth lens (104) and the ninth surface (S9) of the fifth lens (105) may be less than 0.1 mm from the center distance to the edge distance. Since the gap between the fourth lens (104) and the fifth lens (105) is close, the loss of light passing through the fourth and fifth lenses (104, 105) can be reduced.

[0071]

[0072] The sixth lens (106) may have positive (+) or negative (-) refractive power on the optical axis (OA). The sixth lens (106) is the nth lens and may have refractive power of the opposite sign to that of the (n-1)th lens, for example, may have positive refractive power. The sixth lens (106) may include a plastic or glass material. For example, the sixth lens (106) may be provided with a plastic material. The object-side eleventh surface (S11) of the sixth lens (106) on the optical axis (OA) may have a convex shape, and the sensor-side twelfth surface (S12) may have a convex shape. That is, the sixth lens (106) may have a convex shape on both sides on the optical axis (OA). Alternatively, the sixth lens (106) may have a meniscus shape convex toward the object or a meniscus shape convex toward the sensor. Alternatively, the sixth lens (106) may have a concave shape on both sides. At least one or both of the eleventh surface (S11) and the twelfth surface (S12) may be aspherical, and the aspherical coefficient is provided as in FIG. 3, where L6 is the sixth lens (106), L6S1 is the eleventh surface, and L6S2 is the twelfth surface.

[0073] The sixth lens (106) may have a center thickness (CT6) greater than an edge thickness. In terms of the absolute value of Sag, the maximum Sag value (Sag61) of the object-side surface of the sixth lens (106) may be less than the center thickness (CT6) of the sixth lens (106) and less than the maximum Sag value (Sag21) of the sensor-side surface of the second lens (102). In addition, in terms of the absolute value of Sag, the maximum Sag value (Sag61) of the object-side surface of the sixth lens (106) may be greater than the maximum Sag value of the sensor-side surface. The fifth and sixth lenses (105 and 106) may control the path of light refracted toward the image sensor (190) through the fourth lens (104). Therefore, the optical system (1000) according to the embodiment may have improved optical characteristics in the center and periphery of the field of view (FOV).

[0074]

[0075] On the optical axis, the radius of curvature of the first and second surfaces (S1, S2) of the first lens (101) is L1R1, L1R2, the radius of curvature of the third and fourth surfaces (S3, S4) of the second lens (102) is L2R1, L2R2, the radius of curvature of the fifth and sixth surfaces (S5, S6) of the third lens (103) is L3R1, L3R2, the radius of curvature of the seventh and eighth surfaces (S7, S8) of the fourth lens (104) is L4R1, L4R2, the radius of curvature of the ninth and tenth surfaces (S9, S10) of the fifth lens (105) is L5R1, L5R2, and the radius of curvature of the eleventh and twelfth surfaces (S11, S12) of the sixth lens (106) can be defined as L6R1, L6R2. The above curvature radii can satisfy at least one of the following conditions to improve the aberration characteristics of the optical system.

[0076] Condition 1: L1R2*2 < L1R1 Condition 2: L2R1 + L2R2 < L1R1

[0077] Condition 3: L3R1 < L1R2 < L3R2 Condition 4: |L4R2|*4 < L1R1 < L4R1

[0078] Condition 5: |L5R1|*10 < L4R1 < L5R2

[0079] Condition 6: |L4R1-L3R2| < |L1R1-L2R1|

[0080] Condition 7: L6R1 < |L6R2| < L1R1 Condition 8: L1R1*2 < L5R2

[0081] In the absolute value of the radius of curvature of each lens surface, the fourth surface (S4) of the second lens (102) may be the smallest among the lens surfaces, and the tenth surface (S10) of the fifth lens (105) may be the largest among the lens surfaces. In the absolute value of the radius of curvature (average value) of each lens, the fifth lens (105) may be the largest among the lenses. By setting the radius of curvature of each lens, good optical performance can be provided at the focal length of each lens.

[0082]

[0083] The effective lengths of the first to sixth lenses (101-106) may be defined as CA1-CA8. The effective length (CA1) of the first lens (101) may have a maximum effective length within the lens unit (100) and may be 7 mm or more. The effective length (CA4) of the fourth lens (104) may be a minimum within the lens unit (100). The maximum effective lengths of the lenses may be more than twice the minimum effective length, for example, in the range of 3 to 6 times.

[0084] On the optical axis, the effective lengths of the first and second surfaces (S1, S2) of the first lens (101) are CA11, CA12, the effective lengths of the third and fourth surfaces (S3, S4) of the second lens (102) are CA21, CA22, the effective lengths of the fifth and sixth surfaces (S5, S6) of the third lens (103) are CA31, CA32, the effective lengths of the seventh and eighth surfaces (S7, S8) of the fourth lens (104) are CA41, CA42, the effective lengths of the ninth and tenth surfaces (S9, S10) of the fifth lens (105) are CA51, CA52, and the effective lengths of the eleventh and twelfth surfaces (S11, S12) of the sixth lens (106) are CA61, CA62. These effective lengths are factors that affect the aberration characteristics of the optical system and must satisfy at least one of the following conditions.

[0085] Condition 1: CA41 <CA32<CA22<CA21<CA11 조건2:CA4<CA3<CA2<CA1 조건3: CA4 < CA5 < CA6 조건3: CA41 < CA51 < CA52 < CA62 조건4: CA 51 < CA52 < CA32 < CA31 조건5:3≤Max_CA / Min_CA≤ 6

[0086] The effective length (CA11) of the object-side surface (S1) of the first lens (101) is provided as the largest within the optical system, which can increase the amount of incident light. Accordingly, the difference between the effective length of the sensor-side surface (S12) of the sixth lens (106) and the maximum effective length can be set to 2 mm or more depending on the shape of the second lens (102).

[0087] Among the first to sixth lenses (101-106), the number of lenses having an effective length smaller than the diagonal length of the image sensor (190) may be three or more. For example, the effective lengths of the third to sixth lenses (103-106) may be smaller than the diagonal length of the image sensor (190). Among the effective lengths of each lens surface (S1-S12) of the lenses (101-106), the lens surface smaller than the effective diagonal length of the image sensor (190) may be 80% or less of the total lens surfaces, and may be, for example, in the range of 60% to 80%. For example, the effective lengths of the fifth to twelfth surfaces (S5-S12) may be smaller than the effective diagonal length of the image sensor (190). In addition, the effective length of the fourth surface (S3) may be smaller than the effective diagonal length of the image sensor (190).

[0088]

[0089] The number of lenses having a refractive index exceeding 1.6 may be 2 or more, and the number of lenses having a refractive index less than 1.6 may be 2 or more. Among the plastic lenses in the lens unit, the fifth lens (105) has a refractive index of 1.60 or more and can refract light incident through the fourth lens (104) to the entire area of ​​the sixth lens (106). The third lens (103) has the highest refractive index among the lenses and can reduce light loss due to the difference in effective length of the second lens (102) and the fourth lens (104). The average refractive index of the first to sixth lenses (101 to 106) may be 1.60 or more. The number of lenses having an Abbe number exceeding 45 in the optical system may be greater than the number of lenses having an Abbe number less than 45. The average Abbe number of the first to sixth lenses (101 to 106) may be 43 or more. By setting the refractive index and Abbe number of each lens, the effects of chromatic aberration can be controlled.

[0090] When the refractive index of each lens (101-106) is Nd1, Nd2, Nd3, Nd4, Nd5, Nd6, and the Abbe number of each lens (101-106) is Vd1, Vd2, Vd3, Vd4, Vd5, Vd6, at least one of the following conditions can be satisfied.

[0091] Condition 1: Nd2 < Nd1 < Nd3 Condition 2: 1.5 < Nd2, Nd4, Nd6 < 1.6

[0092] Condition 3: 1.6< Nd1,Nd3,Nd5 <2.0 Condition 4: Vd3 < Vd1,Vd2

[0093] Condition 5: Vd5 < Vd4,Vd6 Condition 6: Vd3*Nd3 < Vd1*Nd1

[0094] Condition 7: Vd5*Nd5 < Vd6*Nd6

[0095] Depending on the refractive index and Abbe number, the optical system (1000) can have improved chromatic aberration control characteristics.

[0096]

[0097] The center thicknesses of the first lens (101) to the sixth lens (106) can be defined as CT1 to CT6, and the center intervals between the first to sixth lenses (101-106) can be defined as CG1 to CG5, respectively. In addition, the edge thickness of each lens can be defined as ET1 to ET6. The optical axis distance between the image sensor (190) and the sensor-side surface (S12) of the last lens (106) is the BFL (Back focal length). Here, the edge thickness of each lens can be the distance in the optical axis direction between the effective areas of each lens. The optical system can satisfy at least one of the following conditions.

[0098] Condition 1: CT5 < CT1 < CT2 Condition 2: CT2 < CT3 < CT6

[0099] Condition 3: CT5 < CT4 < CT3 Condition 4: (CT1 + CT2) < CG2

[0100] Condition 5: (CT2 + CT3) < CG2 Condition 6: CT6 < CG2 < CT6*2

[0101] Condition 7: CG4*5 < CG5 < CG3 Condition 8: CG1*5 < CG2 < CG1*15

[0102] Condition 9: CT6 < BFL < CG2

[0103] The center thickness (CT6) of the sixth lens (106) may be the largest among the center thicknesses of the lenses. The center thickness (CT5) of the fifth lens (105) may be the smallest among the center thicknesses of the lenses or may be 0.5 mm or less. The center spacing (CG2) between the second and third lenses (102, 103) may be the largest among the center spacings between adjacent lenses. The center spacing (CG4) between the fourth and fifth lenses (104, 105) may be the smallest among the center spacings between the lenses. The center thickness ratio of the glass lenses satisfies 1 < CT3 / CT1 < 4, and preferably 2 < CT3 / CT1 < 3.

[0104] Among the lenses (101-106), the maximum center thickness may be 8 times or less, for example, 2 to 8 times, the minimum center thickness. Among the lenses, the number of lenses having a center thickness of 0.8 mm or less may be smaller than the number of lenses having a center thickness of more than 0.8 mm. The sum of the center thicknesses of the first to sixth lenses (101-106) may be greater than the sum of the center spacings between the first to sixth lenses (101-106). The difference between the sum of the center thicknesses of the first to sixth lenses (101-106) and the sum of the center spacings between the first to sixth lenses (101-106) may be 3 mm or less. Accordingly, the optical system (1000) can control incident light and have improved aberration characteristics and resolution.

[0105]

[0106] When the focal length of each lens (101-106) is defined as F1, F2, F3, F4, F5, F6, the condition: F2 < F1 can be satisfied in absolute value. In addition, the focal length (absolute value) of the glass material lenses can satisfy the condition: F3 < F1. In addition, the average of the absolute values ​​of the focal lengths of the second to sixth lenses (102-106) sequentially stacked can satisfy a range of 7 mm or less, for example, a range of 2 mm to 7 mm or a range of 2 mm to 5 mm. When the focal lengths are described in absolute value, the focal length (F1) of the first lens (101) can be the largest among the lenses, and the focal length (F5) of the fifth lens (105) is the smallest. The maximum focal length can be 10 times or less of the minimum focal length. The overall focal length of the optical system (1000) may be smaller than the absolute value of the focal length of the first lens (101), for example, smaller than the focal length (F6) of the sixth lens (106).

[0107] These optical systems can be applied to vehicle camera modules, and can be applied to camera modules for front (mono, multi-camera), side, CMS (Camera monitor system), surround view, rear, OMS (Occupant monitoring system) or DMS (Driver monitoring system). For example, the invention can be applied to a camera module for OMS (Occupant monitoring system) or DMS (Driver monitoring system).

[0108] Fig. 4 is a graph showing the diffraction MTF (Modulation Transfer Function) in the optical system of Fig. 1, and is a graph showing the luminance ratio (modulation) according to the spatial frequency. That is, Fig. 4 shows the diffraction MTF at room temperature, and is a graph measuring the luminance ratio according to the defocusing position in the OMS (Occupant monitoring system)-RGB sensor.

[0109] FIG. 5 is a graph showing the aberration characteristics of an optical system at room temperature according to a first embodiment of the invention. Referring to FIG. 5, the graph is a graph measuring spherical aberration (longitudinal spherical aberration), astigmatic field curves, and distortion from left to right in the aberration graph of the optical system. The X-axis may represent a focal length (mm) and a degree of distortion (%), and the Y-axis may represent the height of the image. In addition, the graph for spherical aberration is a graph for light in a wavelength band of about 435 nm, about 481 nm, about 546 nm, about 587 nm, about 656 nm, about 920 nm, about 940 nm, and about 960 nm, and the graph for astigmatism and distortion is a graph for light in a wavelength band of 546 nm. The optical system (1000) according to the embodiments can have improved resolution and good optical performance not only in the center of the field of view (FOV) but also in the periphery. As confirmed in the embodiments, the lens system according to the embodiments of the present invention can satisfactorily correct spherical aberration, astigmatism, distortion aberration, chromatic aberration, and coma aberration with a configuration of 7 or fewer lenses, for example, 6 lenses.

[0110]

[0111] FIGS. 6 to 9 are drawings illustrating an optical system and a camera module according to a second embodiment using FIG. 1. In describing the second embodiment, having the optical system of FIG. 1 and having the same configuration as the first embodiment may include the configuration and description of the first embodiment, and redundant descriptions of the same configuration and features will be omitted.

[0112] Referring to FIGS. 1, 6, and 7, in the lens unit of the second embodiment, the shapes of the first to twelfth surfaces (S1-S12) of the first to sixth lenses (101-106) are concave or convex on the optical axis, and the signs of the power of each lens refer to the first embodiment. For example, the first to third lenses (101-103) have a meniscus shape convex toward the object, the fourth lens (104) is convex on both sides, the fifth lens (105) is concave on both sides, and the sixth lens (106) is convex on both sides. The first, second, and fifth lenses (101, 102, and 105) have negative power, and the third, fourth, and sixth lenses (103, 104, and 106) have positive power.

[0113] The first and second lenses (101, 102) are a first lens group (LG1), and the third to sixth lenses (103-106) are a second lens group (LG2). The aperture (ST) may be arranged between the first lens group (LG1) and the second lens group (LG2). The first and third lenses (101, 103) are made of glass, and the second, fourth, fifth, and sixth lenses (102, 104, 105, 106) are made of plastic.

[0114] Among the first to sixth lenses (101-106), the refractive index of the third lens (103) may be the largest, the effective length of the first lens (101) may be the largest, and the absolute value of the focal length of the first lens (101) may be the largest. Among the first to twelfth surfaces (S1-S12) of the lenses, the first surface (S1) may have the maximum effective length, and the seventh surface (S7) may have the minimum effective length. Among the effective lengths of the lens surfaces (S1-S12), a lens surface that is smaller than the effective diagonal length of the image sensor (190) may be 80% or less of the total lens surfaces, for example, in the range of 60% to 80%. For example, the effective lengths of the fifth to twelfth surfaces (S5-S12) may be smaller than the effective diagonal length of the image sensor (190). Additionally, the effective length of the fourth surface (S3) may be smaller than the effective diagonal length of the image sensor (190).

[0115]

[0116] Among the first to sixth lenses (101-106), the center thickness (CT6) of the sixth lens (106) may be the largest, the center thickness (CT5) of the fifth lens (105) may be the smallest, the edge thickness (ET2) of the second lens (102) may be the largest, and the edge thickness (ET4) of the fourth lens (104) may be the smallest. Among the first to twelfth surfaces (S1-S12) of the lenses, the absolute value of the radius of curvature of the tenth surface (S10) of the fifth lens (105) on the optical axis may be the largest. In the optical axis spacing between adjacent lenses, the optical axis spacing (CG2) between the second and third lenses (102, 103) may be the largest, and the optical axis spacing (CG4) between the fourth and fifth lenses (104, 105) may be the smallest.

[0117] The first to twelfth surfaces (S1-S12) may have a shape without a critical point from the optical axis (OA) to the end of the effective area. The third and fourth surfaces (S3, S4) of the second lens (102), the seventh and eighth surfaces (S7, S8) of the fourth lens (104), the ninth and tenth surfaces (S9, S10) of the fifth lens (105), and the eleventh and twelfth surfaces (S11, S12) of the sixth lens (106) may have an aspherical shape on the optical axis and may have an aspherical coefficient as shown in FIG. 7.

[0118] An aperture (ST) may be arranged on the periphery between the third lens (103) and the fourth lens (104). The aperture (ST) may be arranged closer to the seventh surface (S7) than to the sixth surface (S6). Accordingly, an increase in the effective length of the fourth lens (104) may be prevented. An optical filter (192) may be arranged between the sixth lens (106) and the image sensor (190). The optical filter (192) may be arranged closer to the sixth lens (106) than to the image sensor (190).

[0119]

[0120] The Sag value (Sag22) of the fourth surface (S4) of the second lens (102) may be the largest among the absolute values ​​of the Sag values ​​of the first to twelfth surfaces (S1-S12). The Sag value (Sag61) of the eleventh surface (S11) of the sixth lens (106) may be larger than the absolute value of the Sag value of the twelfth surface (S12). Accordingly, the sixth lens (106) having the maximum thickness may refract light incident through the eleventh surface (S11) to the entire area of ​​the image sensor (190).

[0121] The FOV, TTL, TD, SD, BFL, etc. of the optical system (1000) above will be referred to the first embodiment. Formulas and conditions using optical characteristics such as refractive index, Abbe number, effective length, focal length, radius of curvature, etc. of the first to sixth lenses (101-106) may include the contents disclosed in the first embodiment.

[0122] Fig. 8 is a graph showing the diffraction MTF in the optical system of Fig. 6, and is a graph showing the luminance ratio according to the spatial frequency. That is, Fig. 8 shows the diffraction MTF at room temperature, and is a graph measuring the luminance ratio according to the position of the defocusing position in the OMS-RGB sensor. Fig. 9 is a graph showing the aberration characteristics of the optical system at room temperature according to the second embodiment of the invention. Referring to Fig. 9, it is a graph measuring spherical aberration, astigmatism, and distortion aberration from left to right in the aberration graph of the optical system. The X-axis may represent the focal length (mm) and the distortion degree (%), and the Y-axis may represent the height of the image. In addition, the graph for spherical aberration is a graph for light in a wavelength band of about 435 nm, about 481 nm, about 546 nm, about 587 nm, about 656 nm, about 920 nm, about 940 nm, and about 960 nm, and the graph for astigmatism and distortion is a graph for light in a wavelength band of 546 nm. The optical system (1000) according to the embodiments may have improved resolution and may have good optical performance not only in the center but also in the periphery of the field of view (FOV). As confirmed in the embodiments, the lens system of the embodiment according to the present invention may have a configuration of 7 or less lenses, for example, 6 lenses, and may well correct spherical aberration, astigmatism, distortion, chromatic aberration, and coma aberration.

[0123]

[0124] FIGS. 10 to 13 are drawings illustrating an optical system and a camera module according to a third embodiment using FIG. 1. In describing the third embodiment, having the optical system of FIG. 1 and having the same configuration as the first embodiment may include the configuration and description of the first embodiment, and redundant descriptions of the same configuration and features will be omitted.

[0125] Referring to FIGS. 1, 10, and 11, in the lens unit of the third embodiment, the shapes of the first to twelfth surfaces (S1-S12) of the first to sixth lenses (101-106) are concave or convex on the optical axis, and the signs of the power of each lens refer to the third embodiment. For example, the first to third lenses (101-103) have a meniscus shape convex toward the object, the fourth lens (104) is convex on both sides, the fifth lens (105) is concave on both sides, and the sixth lens (106) is convex on both sides. The first, second, and fifth lenses (101, 102, and 105) have negative power, and the third, fourth, and sixth lenses (103, 104, and 106) have positive power.

[0126] The first and second lenses (101, 102) are a first lens group (LG1), and the third to sixth lenses (103-106) are a second lens group (LG2). The aperture (ST) may be arranged between the first lens group (LG1) and the second lens group (LG2). The first and third lenses (101, 103) are made of glass, and the second, fourth, fifth, and sixth lenses (102, 104, 105, 106) are made of plastic.

[0127] Among the first to sixth lenses (101-106), the refractive index of the third lens (103) may be the largest, the effective length of the first lens (101) may be the largest, and the absolute value of the focal length of the first lens (101) may be the largest. Among the first to twelfth surfaces (S1-S12) of the lenses, the first surface (S1) may have the maximum effective length, and the seventh surface (S7) may have the minimum effective length. Among the effective lengths of the lens surfaces (S1-S12), a lens surface that is smaller than the effective diagonal length of the image sensor (190) may be 80% or less of the total lens surfaces, for example, in the range of 60% to 80%. For example, the effective lengths of the fifth to twelfth surfaces (S5-S12) may be smaller than the effective diagonal length of the image sensor (190). Additionally, the effective length of the fourth surface (S3) may be smaller than the effective diagonal length of the image sensor (190).

[0128] Among the first to sixth lenses (101-106), the center thickness (CT6) of the sixth lens (106) may be the largest, the center thickness (CT5) of the fifth lens (105) may be the smallest, the edge thickness (ET2) of the second lens (102) may be the largest, and the edge thickness (ET4) of the fourth lens (104) may be the smallest. Among the first to twelfth surfaces (S1-S12) of the lenses, the absolute value of the radius of curvature of the tenth surface (S10) of the fifth lens (105) on the optical axis may be the largest. In the optical axis spacing between adjacent lenses, the optical axis spacing (CG2) between the second and third lenses (102, 103) may be the largest, and the optical axis spacing (CG4) between the fourth and fifth lenses (104, 105) may be the smallest. The first to twelfth surfaces (S1-S12) may have a shape without a critical point from the optical axis (OA) to the end of the effective area. The third and fourth surfaces (S3, S4) of the second lens (102), the seventh and eighth surfaces (S7, S8) of the fourth lens (104), the ninth and tenth surfaces (S9, S10) of the fifth lens (105), and the eleventh and twelfth surfaces (S11, S12) of the sixth lens (106) may have an aspherical shape on the optical axis, and may have an aspherical coefficient, as shown in FIG. 11.

[0129]

[0130] The Sag value (Sag22) of the fourth surface (S4) of the second lens (102) may be the largest among the absolute values ​​of the Sag values ​​of the first to twelfth surfaces (S1-S12). The Sag value (Sag61) of the eleventh surface (S11) of the sixth lens (106) may be larger than the absolute value of the Sag value of the twelfth surface (S12). Accordingly, the sixth lens (106) having the maximum thickness may refract light incident through the eleventh surface (S11) to the entire area of ​​the image sensor (190).

[0131] An aperture (ST) may be arranged on the periphery between the third lens (103) and the fourth lens (104). The aperture (ST) may be arranged closer to the seventh surface (S7) than to the sixth surface (S6). Accordingly, an increase in the effective length of the fourth lens (104) may be prevented. An optical filter (192) may be arranged between the sixth lens (106) and the image sensor (190). The optical filter (192) may be arranged closer to the sixth lens (106) than to the image sensor (190).

[0132]

[0133] The FOV, TTL, TD, SD, BFL, etc. of the optical system (1000) above will be referred to the first embodiment. Formulas and conditions using optical characteristics such as refractive index, Abbe number, effective length, focal length, radius of curvature, etc. of the first to sixth lenses (101-106) may include the contents disclosed in the first embodiment.

[0134] Fig. 12 is a graph showing the diffraction MTF in the optical system of Fig. 10, and is a graph showing the luminance ratio according to the spatial frequency. That is, Fig. 12 shows the diffraction MTF at room temperature, and is a graph measuring the luminance ratio according to the position of the defocusing position in the OMS-RGB sensor. Fig. 13 is a graph showing the aberration characteristics of the optical system at room temperature according to the third embodiment of the invention. Referring to Fig. 13, it is a graph measuring spherical aberration, astigmatism, and distortion aberration from left to right in the aberration graph of the optical system. The X-axis may represent the focal length (mm) and the distortion degree (%), and the Y-axis may represent the height of the image. In addition, the graph for spherical aberration is a graph for light in a wavelength band of about 435 nm, about 481 nm, about 546 nm, about 587 nm, about 656 nm, about 920 nm, about 940 nm, and about 960 nm, and the graph for astigmatism and distortion is a graph for light in a wavelength band of 546 nm. The optical system (1000) according to the embodiments may have improved resolution and may have good optical performance not only in the center but also in the periphery of the field of view (FOV). As confirmed in the embodiments, the lens system of the embodiment according to the present invention may have a configuration of 7 or less lenses, for example, 6 lenses, and may well correct spherical aberration, astigmatism, distortion, chromatic aberration, and coma aberration.

[0135] The optical systems of the first to third embodiments disclosed above can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only at the center but also at the periphery of the field of view (FOV). As shown in Fig. 14, a graph showing distortion (%) from the center of the image sensor, that is, from 0 (0.0 Field) to 1.0 Field, in the optical systems according to the first to third embodiments, it can be seen that the distortion is close to 0 up to 0.5 Field, and is located within the range of 0 to -40% overall.

[0136]

[0137] The optical system (1000) according to the embodiment disclosed above can satisfy at least one or two or more of the mathematical equations described below. Accordingly, the optical system (1000) according to the embodiment can have improved optical characteristics. For example, when the optical system (1000) satisfies the mathematical equations, the optical system (1000) can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance even in the center and periphery of the field of view (FOV). The optical system (1000) can have improved resolution, and can have a slimmer and more compact structure. Hereinafter, the units of values ​​such as thickness, spacing, effective length, radius of curvature, and focal length of the first to sixth lenses (101-106) are mm.

[0138] [Mathematical Formula 1] 1 < CT2 / CT1 < 5

[0139] In Mathematical Expression 1, when the central thickness (CT1) of the first lens (101) and the central thickness (CT2) of the second lens (102) are satisfied, the optical system (1000) can improve aberration characteristics. In addition, by making the central thickness (CT2) of the plastic second lens (102) exceed by one time the central thickness (CT1) of the glass first lens (101), the aberration characteristics can be improved. Preferably, Mathematical Expression 1 can satisfy 1 < CT2 / CT1 < 3.

[0140] [Equation 2] 0 < CT2 / ET2 < 1

[0141] When the center thickness (CT2) and the edge thickness (ET2) of the second lens (102) in mathematical expression 2 are satisfied, the optical system (1000) may have improved chromatic aberration control characteristics. Preferably, mathematical expression 2 may satisfy 0.2 < CT2 / ET2 < 0.7. The edge thickness (ET2) of the second lens (102) may be the largest among the edge thicknesses of the lenses.

[0142] [Equation 3] (CT1 + CT2) < CT6

[0143] In mathematical expression 3, by making the central thickness (CT6) of the sixth lens larger than the sum of the central thicknesses of the first and second lenses, light loss in the first lens (101) made of glass and the second lens (102) made of plastic can be reduced, and light can be refracted to the entire area of ​​the image sensor (190) through the thickest sixth lens (106).

[0144] [Equation 4] 2 < CT6 / CT5 < 7

[0145] When the central thickness of the fifth and sixth lenses (105, 106) in mathematical expression 4 is satisfied, the optical system (1000) can have improved chromatic aberration control characteristics. Mathematical expression 4 can satisfy 4 < CT6 / CT5 < 6.5.

[0146] [Mathematical Formula 5] 2 < CT6 / CT1 < 6

[0147] When the center thickness of the first and sixth lenses (101, 106) in mathematical expression 5 is satisfied, the optical system (1000) can have improved chromatic aberration control characteristics. Mathematical expression 5 can satisfy 3 < CT6 / CT1 < 5.

[0148] [Equation 6] 1 < CG2 / CT6 < 3

[0149] In mathematical expression 6, when the optical axis distance (CG2) between the second and third lenses (102, 103) and the center thickness (CT6) of the sixth lens (106) are satisfied, the shape of the second lens (102) and the increase in the effective length of the second lens group (LG2) can be suppressed. Mathematical expression 6 can satisfy 1.2 < CG2 / CT6 < 1.8.

[0150]

[0151] [Equation 7] 1.60 < Nd1 < Nd3

[0152] In mathematical expression 7, when the refractive indices (Nd1, Nd3) at the d-line of the first and third lenses (101, 103) made of glass are satisfied, the light path incident from the first lens (101) to the third lens (103) can be controlled, and an increase in TTL can be suppressed. Preferably, the refractive index of the third lens (103) can satisfy 1.80 < Nd3 < 2.0.

[0153] [Equation 8] 5 < CG2 / CG1 < 25

[0154] In mathematical expression 8, if the optical axis distance (CG1) between the first and second lenses (101, 102) and the optical axis distance (CG2) between the second and third lenses (102, 103) are satisfied, the optical axis distance of the first lens group (LG1) can be reduced. Preferably, mathematical expression 8 can satisfy 8 < CG2 / CG1 < 23.

[0155] [Equation 9] 10 < CT4 / CG4 < 50

[0156] In mathematical expression 9, when the central thickness (CT4) of the fourth lens (104) and the optical axis distance (CG4) between the fourth and fifth lenses are satisfied, the increase in the effective length of the fifth lens can be suppressed and the influence on TTL can be reduced. Mathematical expression 9 can satisfy 15 < CT4 / CG4 < 30.

[0157] [Equation 10] 1 < CT5 / CG5 < 3

[0158] In mathematical expression 10, when the optical axis distance (CG5) between the fifth and sixth lenses and the central thickness of the fifth lens are satisfied, the optical path passing through the fifth and sixth lenses (105, 106) can be adjusted to provide good optical performance in the center and periphery of the field of view (FOV). In addition, the optical system (1000) can reduce distortion, thereby providing improved optical performance. Preferably, mathematical expression 10 can satisfy 1 < CT5 / CG5 < 2.

[0159] [Equation 11] 3 < CT6 / CG5 < 12

[0160] In mathematical expression 11, when the central thickness (CT6) of the sixth lens and the optical axis distance (CG5) between the fifth and sixth lenses are satisfied, the optical system (1000) can improve aberration characteristics and control the size of the optical system (1000), for example, reduction of the total track length (TTL). Preferably, mathematical expression 11 can satisfy 6 < CT6 / CG5 < 9.

[0161] [Equation 12] 3 < CG5 / CG4 < 10

[0162] When the optical axis spacing between the fourth, fifth, and sixth lenses in mathematical expression 12 is satisfied, the optical system (1000) can have improved aberration characteristics. In addition, the optical system (1000) can have good optical performance at a set angle of view and control the total track length (TTL). Preferably, mathematical expression 12 can satisfy 6 < CG5 / CG4 < 8.

[0163] [Equation 13] 3 < CG1 / CG4 < 10

[0164] In mathematical expression 13, when the optical axis distance (CG1) between the first and second lenses (101, 102) and the optical axis distance (CG4) between the fourth and fifth lenses (104, 105) are satisfied, the optical system (1000) can reduce the optical axis distance of the second lens group (LG2). Preferably, mathematical expression 13 can satisfy 3 < CG1 / CG4 < 8.

[0165]

[0166] [Equation 14] 10 < L5R2 / L6R1 < 70

[0167] In mathematical expression 14, when the radius of curvature (L5R2) of the optical axis of the tenth surface (S10) of the fifth lens (105) and the radius of curvature (L6R1) of the optical axis of the eleventh surface (S11) of the sixth lens (106) are satisfied, the effective length of the sixth lens (106) can be provided to be greater than the effective length of the fifth lens (105), and the aberration characteristics of the optical system (1000) can be improved. Preferably, mathematical expression 14 can satisfy 15 < L5R2 / L6R1 < 60.

[0168]

[0169] [Equation 15] 1 < L1R1 / L2R1 < 5

[0170] In mathematical expression 15, if the radius of curvature (L1R1) of the object-side surface of the first lens and the radius of curvature (L2R1) of the object-side surface of the second lens are satisfied, the degradation of characteristics due to the glass material of the first lens can be prevented, and the amount of incident light can be increased. Preferably, 1 < L1R1 / L2R1 < 3 can be satisfied.

[0171] [Equation 16] 0 < CA11 / CA22 < 2

[0172] In Mathematical Expression 16, when the effective length (CA11) of the first surface (S1) of the first lens (101) and the effective length (CA22) of the fourth surface (S4) of the second lens (102) are satisfied, the optical system (1000) can maintain incident light control and optical performance and have improved aberration control characteristics. Mathematical Expression 16 can preferably satisfy 1 < CA11 / CA22 < 2. The effective length (CA11) of the first surface (S1) of the first lens (101) can be the largest among the effective lengths of the lens surfaces.

[0173] [Mathematical Formula 17] 0.5 < CA52 / CA31 < 1.5

[0174] In mathematical expression 17, when the effective length (CA31) of the fifth surface (S5) of the third lens (103) and the effective length (CA52) of the tenth surface (S10) of the fifth lens (105) are satisfied, the optical system (1000) can control the path of light incident on the second lens group (LG2) and improve aberration characteristics. Preferably, mathematical expression 17 can satisfy 0.5 < CA52 / CA31 < 1.

[0175] [Equation 18] 1 < CA22 / CA31 < 2.5

[0176] In the case where the effective length (CA22) of the fourth surface (S4) of the second lens (102) and the effective length (CA31) of the fifth surface (S5) of the third lens (103) in mathematical expression 18 are satisfied, the difference in effective length between the first and second lens groups (LG1, LG2) can be reduced, and light loss can be suppressed. In addition, the optical system (1000) can improve chromatic aberration and control vignetting for optical performance. Preferably, mathematical expression 18 can satisfy 1 < CA22 / CA31 < 2.

[0177] [Equation 19] 0.5 < CA42 / CA52 < 1.5

[0178] In mathematical expression 19, if the effective length (CA42) of the eighth surface (S8) of the fourth lens (104) and the effective length (CA52) of the tenth surface (S10) of the fifth lens (105) are satisfied, an optical path that proceeds to the second lens group (LG2) can be set. In addition, the optical system (1000) can improve chromatic aberration. Preferably, mathematical expression 19 can satisfy 0.5 < CA42 / CA52 < 1.

[0179]

[0180] [Mathematical Formula 20] 1 < CA11 / CA62 < 3

[0181] In mathematical expression 20, if the effective length (CA62) of the twelfth surface (S12) of the sixth lens (106) and the effective length (CA11) of the first surface (S1) of the first lens (101) are satisfied, the effective length and optical path between the incident lens and the last lens can be set. Accordingly, the optical system (1000) can set the angle of view and the optical system size. Preferably, mathematical expression 20 can satisfy 1.5 < CA11 / CA62 < 2.5.

[0182] [Mathematical Formula 21] 1 < (CA1*CT1) / (CA6*CT6) < 2

[0183] In mathematical expression 21, when the product of the effective length and the central thickness of the first lens (101) is greater than the product of the effective length and the central thickness of the sixth lens (106), the optical system (1000) can improve the amount of incident light and maintain optical performance. Preferably, 1.1 < (CA1*CT1) / (CA6*CT6) < 1.7 can be satisfied.

[0184] [Mathematical Formula 22] 5mm < Aver(CA1,CA2) < 10mm

[0185] In mathematical expression 22, Aver(CA1,CA2) is the average of the effective lengths of the first and second lenses (101,102). If this is satisfied, the effective lengths of the second and third lenses can be controlled, and TTL can be reduced. Mathematical expression 22 can satisfy 6mm < Aver(CA1,CA2) < 9mm.

[0186] [Mathematical Formula 23] 2 < Aver(CA1,CA2) / Aver(CA4,CA5) < 5

[0187] In Equation 23, Aver(CA4,CA5) is the average of the effective lengths of the fourth and fifth lenses (104,105). If the first and second lenses, which have greater effective lengths than the other lenses, and the fourth and fifth lenses, which have smaller effective lengths than the other lenses, satisfy Equation 23, the path of light can be controlled. Equation 23 can satisfy 3 < Aver(CA1,CA2) / Aver(CA4,CA5) < 4.

[0188] [Mathematical Formula 24] 1mm < Aver(CA3,CA4,CA5) < 3mm

[0189] Aver(CA3, CA4, CA5) is the effective length of the third, fourth, and fifth lenses, and the effective lengths of the third, fourth, and fifth lenses may be shorter than those of the first, second, and sixth lenses. When mathematical expression 24 is satisfied, light incident through the first and second lenses (101, 102) can be refracted into the effective areas of the third, fourth, and fifth lenses (103, 104, 105) and then guided to the entire area of ​​the sixth lens (106).

[0190] [Equation 25] 0.5 < BFL / CT6 < 1.5

[0191] In mathematical expression 25, when the central thickness (CT6) of the sixth lens and the optical axis distance (BFL) between the sixth lens and the image sensor (190) are satisfied, the optical path can be adjusted according to the central thickness (CT6) of the sixth lens and the installation space of the optical filter (190) can be secured. Preferably, 0.5 < BFL / CT6 < 1 can be satisfied.

[0192] [Equation 26] 0.5 < |L4R2 / L5R1| < 1.5

[0193] In mathematical expression 26, when the radius of curvature of the sensor-side surface of the fourth lens and the radius of curvature of the object-side surface of the fifth lens are satisfied, the optical system (1000) can adjust the refractive power of the fourth and fifth lenses and suppress an increase in the effective length of the sixth lens (106). Preferably, mathematical expression 26 can satisfy 1 < |L4R2 / L5R1| < 1.6.

[0194] [Equation 27] 50 < L5R2 / CT5

[0195] In mathematical expression 27, when the radius of curvature (L5R2) of the tenth surface (S10) of the fifth lens and the central thickness (CT5) of the fifth lens are satisfied, the optical system (1000) can control the refractive power of the fifth lens and improve the optical performance of light incident on the second lens group (LG2). Preferably, mathematical expression 27 can satisfy the condition of 100 < L5R2 / CT5 and L5R2 > 0.

[0196] [Equation 28] 5 < L4R1 / L6R1 < 30

[0197] In mathematical expression 28, when the radius of curvature (L4R1) of the seventh surface (S7) of the fourth lens and the radius of curvature (L6R1) of the eleventh surface (S11) of the sixth lens (106) are satisfied, the shape and refractive power of the fourth and sixth lenses can be controlled to improve the optical performance, and the optical performance of the second lens group (LG2) can be improved. Preferably, mathematical expression 28 can satisfy 5 < L4R1 / L6R1 < 15. Preferably, the conditions of L4R1 > 0 and L6R1 > 0 can be satisfied.

[0198] [Equation 29] 1 < L1R1 / L1R2 < 10

[0199] Mathematical expression 29 can set the radius of curvature (L1R1, L1R2) of the object-side first surface (S1) and second surface (S2) of the first lens, and when this is satisfied, the lens size and resolution can be set. Preferably, Mathematical expression 29 can satisfy 2 < L1R1 / L1R2 < 6. Preferably, L1R1 > 0 and L1R2 > 0 can be satisfied.

[0200] [Equation 30] 0 < L2R2 / L2R1 < 1

[0201] Mathematical expression 30 can set the radius of curvature (L2R1, L2R2) of the object-side third surface (S3) and fourth surface (S4) of the second lens (102), and when this is satisfied, the resolution of the second lens can be determined. Preferably, Mathematical expression 30 can satisfy 0 < L2R2 / L2R1 < 0.5. Preferably, L2R1 > 0 and L2R2 > 0 can be satisfied.

[0202]

[0203] [Equation 31] 0.2 < CT_Max / CG_Max < 1.2

[0204] In mathematical expression 31, the maximum center thickness (CT_Max) and the maximum optical axis spacing (CG_Max) of the lenses can be set, and when these are satisfied, the optical system (1000) has good optical performance at the set angle of view and focal length, and the optical system (1000) can be reduced in size, for example, the total track length (TTL) can be reduced. Preferably, mathematical expression 31 can satisfy 0.5 < CT_Max / CG_Max < 1.

[0205] [Equation 32] 1 < ΣCT / ΣCG < 4

[0206] In mathematical expression 32, ΣCT means the sum of the central thicknesses (mm) of each of the plurality of lenses, and ΣCG means the sum of the spacings (mm) on the optical axis (OA) between two adjacent lenses among the plurality of lenses. When the optical system (1000) according to the embodiment satisfies mathematical expression 32, the optical system (1000) has good optical performance at a set angle of view and focal length, and can reduce the size of the optical system (1000), for example, reduce the total track length (TTL). Preferably, mathematical expression 32 can satisfy 1 < ΣCT / ΣCG < 2.

[0207] [Mathematical Formula 33] 5 < ΣIndex < 15

[0208] In mathematical expression 33, ΣIndex means the sum of the refractive indices at the d-line of each of the plurality of lenses. When the optical system (1000) according to the embodiment satisfies mathematical expression 33, the TTL of the optical system (1000) can be controlled and improved resolution can be achieved. Here, the average refractive indices of the first to sixth lenses can be 1.50 or more. Preferably, mathematical expression 33 can satisfy 7 < ΣIndex < 12 and can satisfy the condition of ΣIndex*n < 60, where n is the total number of lenses.

[0209] [Equation 34] 10 < ΣAbbe / ΣIndex < 50

[0210] In mathematical expression 34, ΣAbbe means the sum of the Abbe numbers of each of the plurality of lenses. When the optical system (1000) according to the embodiment satisfies mathematical expression 34, the optical system (1000) can have improved aberration characteristics and resolution. Preferably, mathematical expression 34 can satisfy 20 < ΣAbbe / ΣIndex < 35. Preferably, the condition of 250 < (ΣAbbe - ΣIndex) < 300 can be satisfied.

[0211] [Equation 35] 0.5 < CG2 / CA31 < 1.5

[0212] In mathematical expression 35, if the optical axis distance (CG2) between the second and third lenses and the effective length (CA31) of the object-side surface of the third lens (103) are satisfied, the radius of curvature of the sensor-side surface of the second lens can be controlled. Preferably, 0.8 < CG2 / CA31 < 1.3 can be satisfied.

[0213] [Equation 36] 1 < Max(CT / ET) < 3

[0214] In mathematical expression 36, Max(CT / ET) represents the largest value in the ratio of the center thickness to the edge thickness of each lens, and can set the shape of the third or sixth lens. Preferably, 1.3 < Max(CT / ET) < 2.5 can be satisfied.

[0215] [Equation 37] 2 < CA11 / CA_Min < 7

[0216] When mathematical expression 37 satisfies the effective length (CA11) of the first surface (S1) of the first lens and the minimum effective length (CA_Min) of the lens surfaces, the amount of light incident through the first lens (101) can be controlled, and a slim optical system can be provided while maintaining optical performance. Preferably, mathematical expression 37 can satisfy 4 < CA11 / CA_Min < 6.

[0217] [Equation 38] 0 < CA_min / ImgH < 1

[0218] In mathematical expression 38, the smallest effective length (CA_min) among the object-side and sensor-side surfaces of the plurality of lenses and half of the diagonal length of the image sensor can be set. When the optical system (1000) according to the embodiment satisfies mathematical expression 38, a slim and compact optical system can be provided while maintaining optical performance. Preferably, mathematical expression 38 can satisfy 0.2 < CA_min / ImgH < 0.8.

[0219] [Equation 39] 2 < CA_Max / F < 6

[0220] In mathematical expression 39, the maximum effective length (CA_Max) among the object-side and sensor-side surfaces of the plurality of lenses and the total effective focal length can be set, and if this is satisfied, a slim and compact optical system can be provided. Preferably, mathematical expression 39 can satisfy 4 < CA_Max / F < 5.5.

[0221] [Mathematical Formula 40] 1 < (CA11*CT1) / (CA31*CT3) < 2

[0222] In mathematical expression 40, the ratio of the effective center thickness of the object-side surface of the glass lenses can be set. Accordingly, the degradation of optical performance due to heat within the camera module can be prevented. Preferably, 1 < (CA11*CT1) / (CA31*CT3) < 1.5 can be satisfied.

[0223] [Mathematical Formula 41] 1 < CA_Max / (2*ImgH) < 2

[0224] In mathematical expression 41, the largest effective length (CA_Max) among the object-side and sensor-side surfaces of the plurality of lenses and the diagonal length (ImgH*2) of the image sensor (190) can be set, and when these are satisfied, the optical system (1000) can have good optical performance in the center and periphery of the field of view (FOV) and provide a slim and compact optical system. Preferably, mathematical expression 41 can satisfy 1.3 < CA_Max / (2*ImgH) < 1.9.

[0225] [Equation 42] 1 < TD / CA_Max < 3

[0226] In mathematical expression 42, TD is the maximum optical axis distance (mm) from the object-side surface of the first lens to the sensor-side surface of the last lens. For example, TD is the distance from the first surface (S1) of the first lens (101) to the twelfth surface (S12) of the sixth lens (106) on the optical axis (OA). When the optical system (1000) according to the embodiment satisfies mathematical expression 42, a slim and compact optical system can be provided. Preferably, mathematical expression 42 can satisfy 1 < TD / CA_max < 1.5.

[0227] [Equation 43] 0 < F / L5R2 < 0.5

[0228] In mathematical expression 43, the total effective focal length (F) of the optical system (1000) and the radius of curvature (L5R2) of the tenth surface (S10) of the fifth lens (105) can be set, and when these are satisfied, the optical system (1000) can be reduced in size, for example, the total track length (TTL) can be reduced. Preferably, mathematical expression 43 can satisfy 0 < F / L5R2 < 0.1.

[0229]

[0230] [Equation 44] 0 < F / L1R1 < 0.5

[0231] In mathematical expression 44, the radius of curvature (L1R1) of the first surface (S1) of the first lens and the total effective focal length (F) can be set, and when these are satisfied, the optical system (1000) can reduce the size of the optical system (1000), for example, reduce the total track length (TTL). Preferably, mathematical expression 44 can satisfy 0 < F / L1R1 < 0.1.

[0232] [Equation 45] 0 < EPD / |L6R2| < 0.5

[0233] In mathematical expression 45, the entrance pupil (EPD) of the optical system (1000) and the radius of curvature of the sensor-side surface of the sixth lens can be set. When the optical system (1000) satisfies mathematical expression 45, the optical system (1000) can control the overall brightness and have good optical performance in the center and periphery of the field of view (FOV). Preferably, mathematical expression 45 can satisfy 0 < EPD / |L6R2| < 0.1.

[0234] [Equation 46] 0 < EPD / L1R1 < 0.5

[0235] Mathematical expression 46 represents the relationship between the incidence pupil of the optical system and the radius of curvature of the first surface (S1) of the first lens, and can control the incident light. Preferably, Mathematical expression 46 can satisfy 0 < EPD / L1R1 < 0.1.

[0236] [Equation 47] 0 < │F1 / F2│ < 2

[0237] In mathematical expression 47, the focal lengths (F1, F2) of the first and second lenses can be set. Accordingly, the refractive power of the incident light of the first and second lenses can be adjusted to improve the resolution and control the TTL. Preferably, mathematical expression 47 can satisfy 0.5 < │F1 / F2│ < 1, and can satisfy the conditions of F1 < 0 and F2 < 0.

[0238] [Equation 48] 1 < │F12│ / F < 5

[0239] By setting the composite focal length (F12) of the first and second lenses and the total focal length (F) in mathematical expression 48, the optical system (1000) can improve the resolution by adjusting the refractive power of the incident light and can control the TTL (total track length) of the optical system (1000). Preferably, mathematical expression 48 can satisfy 1 < │F12│ / F < 2. The composite focal length (F12) of the first and second lenses is the focal length of the first lens group (LG1), and F12 < 0 and F > 0.

[0240] [Equation 49] 1 < |F36 / F12| < 3

[0241] In mathematical expression 49, the composite focal length (F12) of the first and second lenses and the composite focal length (F36) of the third to sixth lenses can be set, and when this is satisfied, the refractive power of the first lens group and the refractive power of the second lens group can be controlled to improve the resolution, and the optical system can be provided in a slim and compact size. In addition, when mathematical expression 49 is satisfied, the optical system (1000) can improve aberration characteristics such as chromatic aberration and distortion aberration. The mathematical expression 49 can preferably satisfy 1 < |F36 / F12| < 1.5. Here, the condition of F36 > 0 can be satisfied.

[0242] [Mathematical Formula 50] 1 < F1 / |F12| < 6

[0243] In mathematical expression 50, the focal length (F1) of the first lens (101) and the combined focal length (F12) of the first and second lenses can be set, thereby improving the resolution of the first lens group. Mathematical expression 50 can satisfy 2 < F1 / |F12| < 6.

[0244] [Mathematical Formula 51] 1 < |F1 / F36| < 6

[0245] In mathematical expression 51, the focal length (F1) of the first lens and the composite focal length (F36) of the third-sixth lens can be set to adjust the resolution of the second lens group. Preferably, mathematical expression 51 can satisfy 3 < |F1 / F36 < 5.

[0246] [Mathematical Formula 52] 1mm < Aver (|F3|+ |F4|+ |F5|+ |F6|) < 6mm

[0247] By setting the average of the refractive powers of the third to sixth lenses in mathematical expression 52, the optical system size and the resolution of the second lens group can be adjusted. 2 mm < Aver (|F3|+ |F4|+ |F5|+ |F6|) < 5 mm can be satisfied.

[0248] [Equation 53] 0 < |F1 / F4| < 1

[0249] In mathematical expression 53, by setting the focal length (F1) of the first lens and the focal length (F4) of the fourth lens, the refractive power of light incident on the first and second lens groups can be controlled, and the optical system size and resolution can be adjusted. Preferably, mathematical expression 53 can satisfy 0 < |F1 / F4| < 0.5, and F4 > 0.

[0250]

[0251] [Mathematical Formula 54] 5mm < TTL < 30mm

[0252] In mathematical expression 54, TTL (Total track length) means the distance from the center of the first surface (S1) of the first lens to the upper surface of the image sensor (190) on the optical axis (OA). Preferably, mathematical expression 54 can satisfy 10 mm < TTL < 25 mm.

[0253] [Mathematical Formula 55] 2mm < ImgH

[0254] Mathematical expression 55 can provide an optical system having high resolution by setting the diagonal size (2*ImgH) of the image sensor (190) to exceed 4 mm. Mathematical expression 55 can preferably satisfy 2.3 mm < ImgH < 6 mm or 2.5 mm ≤ ImgH ≤ 3.5 mm.

[0255] [Mathematical Formula 56] BFL < 2.5 mm

[0256] Mathematical expression 56 can secure an installation space for an optical filter (192) by setting the BFL (Back focal length) to less than 2.5 mm, improve the assemblability of components through the gap between the image sensor (190) and the last lens, and improve the bonding reliability. Mathematical expression 56 can preferably satisfy 1.5 mm < BFL < 2.5 mm.

[0257] [Mathematical Formula 57] 1mm < F < 20mm

[0258] In mathematical expression 57, the overall focal length (F) can be set to suit the optical system, and preferably, 1 mm < F < 10 mm or 1 mm < F < 5 mm can be satisfied.

[0259] [Mathematical Formula 58] FOV < 120 degrees

[0260] In mathematical expression 58, FOV (Field of view) refers to the angle of view (Degree) of the optical system (1000), and can provide an optical system of less than 120 degrees. The FOV can be 30 degrees or more, for example, in the range of 30 degrees to 100 degrees.

[0261] [Mathematical Formula 59] 1 < TTL / CA_Max < 3

[0262] By setting the largest effective length (CA_Max) and TTL among the object-side and sensor-side faces of the plurality of lenses in mathematical expression 59, a slim and compact optical system can be provided. Preferably, mathematical expression 59 can satisfy 1 < TTL / CA_max < 2.

[0263] [Equation 60] 2 < TTL / ImgH < 7

[0264] Mathematical expression 60 can set the total optical axis length (TTL) of the optical system and the diagonal length (ImgH) from the optical axis of the image sensor (190). If the optical system (1000) according to the embodiment satisfies Mathematical expression 60, it can have high-quality implementation and a slim structure. Preferably, Mathematical expression 60 can satisfy 3 < TTL / ImgH < 6.

[0265] [Equation 61] 0.01 < BFL / ImgH < 1

[0266] Mathematical expression 61 can set the optical axis distance between the image sensor (190) and the last lens and the diagonal length from the optical axis of the image sensor (190). When the optical system (1000) according to the embodiment satisfies Mathematical expression 61, the optical system (1000) can secure a back focal length (BFL) and minimize the distance between the last lens and the image sensor (190), thereby having good optical characteristics in the center and periphery of the field of view (FOV). Preferably, Mathematical expression 61 can satisfy 0.5 < BFL / ImgH < 1.

[0267] [Equation 62] 4 < TTL / BFL < 12

[0268] Mathematical expression 62 can set the total optical axis length (TTL) of the optical system and the optical axis distance (BFL) between the image sensor (190) and the last lens. When the optical system (1000) according to the embodiment satisfies Mathematical expression 62, the optical system (1000) can be provided in a slim and compact manner while securing BFL. Mathematical expression 62 can satisfy 4 < TTL / BFL < 9.

[0269] [Equation 63] 0 < F / TTL < 1

[0270] Mathematical expression 63 can set the overall focal length (F) and overall optical axis length (TTL) of the optical system (1000). Accordingly, a slim and compact optical system can be provided. Mathematical expression 63 preferably satisfies 0 < F / TTL < 0.3.

[0271] [Equation 64] 0.5 < F / BFL < 1.5

[0272] Mathematical expression 64 can set the total focal length (F) of the optical system (1000) and the optical axis distance (BFL) between the image sensor (190) and the last lens. When the optical system (1000) according to the embodiment satisfies Mathematical expression 64, the optical system (1000) can have a set angle of view and an appropriate focal length, and can provide a slim and compact optical system. In addition, the optical system (1000) can minimize the distance between the last lens and the image sensor (190), and thus can have good optical characteristics in the periphery of the field of view (FOV). Preferably, Mathematical expression 64 can satisfy 0.5 < F / BFL < 1.

[0273] [Equation 65] 0 < F / ImgH < 3

[0274] Mathematical expression 65 can set the total focal length (F) of the optical system (1000) and the diagonal length (ImgH) from the optical axis of the image sensor (190). This optical system (1000) can have improved aberration characteristics. Preferably, Mathematical expression 65 can satisfy 0.5 < F / ImgH < 1.

[0275] [Equation 66] 1 < F / EPD < 5

[0276] Mathematical expression 66 can set the overall focal length (F) and entrance pupil (EPD) of the optical system (1000). Accordingly, the overall brightness of the optical system can be controlled. Preferably, Mathematical expression 66 can satisfy 1 < F / EPD < 3.

[0277]

[0278] [Equation 67] 0 < BFL / TD < 0.3

[0279] In mathematical expression 67, the optical axis distance (BFL) between the image sensor (190) and the last lens and the optical axis distance (TD) of the lenses are set, and when these are satisfied, the optical system (1000) can provide a slim and compact optical system. Preferably, mathematical expression 67 can satisfy 0 < BFL / TD < 0.2. When BFL / TD exceeds 0.3, the BFL is designed to be large compared to the TD, so that the size of the entire optical system increases, making it difficult to miniaturize the optical system, and since the distance between the sixth lens and the image sensor becomes long, an unnecessary amount of light may increase through the sixth lens and the image sensor, which causes a problem of lowering the resolution such as deterioration of aberration characteristics.

[0280] [Mathematical Formula 68] 0 < EPD / ImgH / FOV < 0.2

[0281] In mathematical expression 68, the relationship between the entrance pupil size (EPD), the length of half the maximum diagonal length of the image sensor (ImgH), and the field of view (FOV) can be established. Accordingly, the overall size and brightness of the optical system can be controlled. Mathematical expression 68 preferably satisfies 0 < EPD / ImgH / FOV < 0.1.

[0282] [Equation 69] 10 < FOV / F# < 55

[0283] Mathematical expression 69 can establish the relationship between the angle of view and the F number of an optical system. Mathematical expression 69 can preferably satisfy 20 < FOV / F# < 40.

[0284] [Equation 70] 0 < Nd1 / Nd2 < 1.5

[0285] When the refractive indices (Nd1, Nd2) at the d-line of the first and second lenses of mathematical expression 70 satisfy the above range, the optical system can improve the resolution of incident light. Preferably, the condition of 1 < Nd1 / Nd2 < 1.25 can be satisfied. That is, the refractive indices of the glass lens and plastic lens adjacent to the object can be set.

[0286] [Mathematical Formula 71] 0 < Nd3 / Nd4 < 1.5

[0287] When the refractive indices (Nd3, Nd4) of the third and fourth lenses in the d-line of mathematical expression 71 satisfy the above range, the optical system can improve the resolution for incident light of the second lens group (LG2). Preferably, mathematical expression 71 can satisfy 1 < Nd3 / Nd4 < 1.3. That is, the refractive indices of the glass lens and plastic lens adjacent to the aperture can be set.

[0288] [Mathematical Formula 72] (Vd3*Nd3) < (Vd1*Nd1)

[0289] In mathematical expression 72, if the refractive index (Nd1) and Abbe number (Vd1) of the first lens and the refractive index (Nd3) and Abbe number (Vd3) of the third lens are satisfied, the color dispersion of light transmitted through the first and third lenses made of glass can be controlled.

[0290] [Mathematical Formula 73] (Vd2*Nd2) < (Vd1*Nd1)

[0291] In mathematical expression 73, if the refractive index (Nd1) and Abbe number (Vd1) of the first lens and the refractive index (Nd3) and Abbe number (Vd3) of the third lens are satisfied, the color dispersion of light transmitted through the first lens made of glass and the third lens made of plastic can be controlled.

[0292] [Mathematical Formula 74] (Vd3*Nd3) < (Vd2*Nd2)

[0293] In mathematical expression 74, if the refractive index (Nd2) and Abbe number (Vd2) of the second lens and the refractive index (Nd2) and Abbe number (Vd2) of the second lens are satisfied, the color dispersion of light transmitted through the first lens made of glass and the second lens made of plastic can be controlled.

[0294] [Equation 75] 10 < (TD_LG2 / TD_LG1)*n < 50

[0295] TD_LG2 is the optical axis distance of the second lens group, TD_LG1 is the optical axis distance of the first lens group, and n is the total number of lenses. The optical axis distance of each lens group can be set according to the total number of lenses by mathematical expression 75. The optical axis distance of the first lens group is the optical axis distance from the object-side surface of the first lens to the sensor-side surface of the second lens, and the optical axis distance of the second lens group is the optical axis distance from the object-side surface of the third lens to the sensor-side surface of the sixth lens.

[0296] [Equation 76] 25 < (CT_Max+CG_Max)*n < 40

[0297] The sum of the thicknesses of the lenses and the sum of the gaps between the lenses can be set according to the total number of lenses by mathematical expression 76.

[0298] [Mathematical Formula 77] 100 < (FOV*TTL) / n < 200

[0299] Preferably, mathematical expression 77 can set the total optical axis length according to the angle of view and the number of lenses (n), and can satisfy the condition of 140 < (FOV*TTL) / n < 165.

[0300] [Mathematical Formula 78] FOV < (TTL*n)

[0301] [Equation 79] 500 < CA_Max*TD*n < 750

[0302] [Equation 80] 0.1 < GLn / PLn < 1

[0303] In mathematical expression 80, the number of glass lenses (GLn) and the number of plastic lenses (PLn) within the lens unit can be set. In mathematical expressions 74 to 80, n represents the total number of lenses, and according to the total number of lenses, the relationship between the optical axis distance (TD_LG1) of the first lens group (LG1), the optical axis distance (TD_LG2) of the second lens group (LG2), the maximum center thickness (CT_Max) of the lenses, the maximum center spacing (CG_max), FOV, TTL, and the optical axis distance (TD) of the lenses can be set. Accordingly, the chromatic aberration, resolution, size, etc. of an optical system having 7 or fewer lenses can be controlled.

[0304]

[0305] [Equation 81]

[0306]

[0307] In mathematical expression 81, Z may represent Sag, which is the distance from any position on the aspherical surface to the vertex of the aspherical surface in the direction of the optical axis. Y may represent the distance from any position on the aspherical surface to the optical axis in the direction perpendicular to the optical axis. c may represent the curvature of the lens, and K may represent the conic constant. In addition, A, B, C, D, E, F, etc. may represent aspheric coefficients.

[0308] The optical system (1000) according to the embodiment can satisfy at least one or two or more mathematical equations from mathematical equations 1 to 80. In this case, the optical system (1000) can have improved optical characteristics. Specifically, when the optical system (1000) satisfies at least one or two or more of mathematical equations 1 to 80, the optical system (1000) can have improved resolution and improve aberration and distortion characteristics. In addition, the optical system (1000) can secure a BFL for applying a large-sized image sensor (190), and can minimize the gap between the last lens and the image sensor (190), thereby having good optical performance in the center and periphery of the field of view (FOV). In addition, when the optical system (1000) satisfies at least one of mathematical expressions 1 to 80, it can include a relatively large-sized image sensor (190) and have a relatively small TTL value, and can provide a slimmer and more compact optical system and a camera module having the same.

[0309]

[0310] Table 1 shows the items of the mathematical formulas described above in the optical system (1000) according to the embodiments, including the TTL, BFL, F value which is the total effective focal length of the optical system (1000), ImgH, the focal lengths (F1, F2, F3, F4, F5, F6) of each of the first to sixth lenses, edge thickness (mm), composite focal length, etc.

[0311] Item Example 1 Example 2 Example 3 F1.9862.0132.002F1-13.180-13.106-13.147F2-3.798-3.706-3.751F33.8633.8943.871F43.5943.5783.565F5-2.568-2.590-2.559F63. 3983.4683.423F12-2.801-2.760-2.789F263.3833.4153.395ET11.1471.2381 .262ET21.9121.9601.977ET30.8220.9340.931ET40.6600.6050.593ET50.685 0.6220.649ET61.4831.1311.120ΣIndex9.8019.8369.823ΣAbbe280.200279. 580279.219ΣCT6.3096.3426.374ΣCG4.6014.5074.496FOV70.00070.000140.0 00EPD0.8840.8960.891BFL2.0572.1572.098TD10.91010.84910.870ImgH2.88 72.8832.885SD3.9503.9563.921TTL12.97012.99812.970F#2.2482.2472.248

[0312] Table 2 shows the results for the mathematical expressions 1 to 40 described above in the optical system (1000) of FIG. 1. Referring to Table 2, it can be seen that the optical system (1000) satisfies at least one, two or more, or three or more of the mathematical expressions 1 to 40. In detail, it can be seen that the optical system (1000) according to the embodiment satisfies all of the mathematical expressions 1 to 40. Accordingly, the optical system (1000) can improve optical performance and optical characteristics in the center and periphery of the field of view (FOV).

[0313] Mathematical FormulaExample 1Example 2Example 311 < CT2 / CT1 < 51.7511.6121.55020 < CT2 / ET2 < 10.4850.4690.4623(CT1+CT2) < CT6SatisfiedSatisfiedSatisfied42 < CT6 / CT5 < 75.0905.9575.78852 < CT6 / CT1 < 64.1513.8613.73461 < CG2 / CT6 < 31.4391.4351.44171.60 < Nd1 < Nd3SatisfiedSatisfiedSatisfied85 < GG2 / CG1 < 2511.08219.23019.220910 < CT4 / CG4 < 5024.58820.66923.232101 < CT5 / CG5 < 31.5761.1741.273113 < CT6 / CG5 < 128.0236.9917.368123 < CG5 / CG4 < 106.9897.1517.552133 < CG1 / CG4 < 107.2793.7314.1711410 < L5R2 / L6R1 < 7025.35351.63528.245151 < L1R1 / L2R1 < 52.0372.6482.673160 < CA11 / CA22 < 21.4511.4521.457170.5 < CA52 / CA31 < 1.50.8220.8080.826181 < CA22 / CA31 < 2.51.4001.3921.393190.5 < CA42 / CA52 < 1.50.7350.7520.750201 < CA11 / CA62 <31.9771.9621.965211 < (CA1*CT1) / (CA6*CT6) < 21.3181.3981.457225 < Aver(CA1,CA2) < 107.0686.9867.037232 < Aver(CA1,CA2) / Aver(CA4,CA5) < 53.5063.4633.437241 < Aver(CA3,CA4,CA5) < 31.5521.5491.523250.5 < BFL / CT6 < 1.50.9350.9800.954260.5 < |L4R2 / L5R1| < 1.51.1381.1411.1362750 < L5R2 / CT5115.909282.615147.854285 < L4R1 / L6R1 < 3011.37411.87411.654291 < L1R1 / L1R2 <103.3043.9954.015300 < L2R2 / L2R1 < 10.1600.1600.158310.2 < CT_Max / CG_Max < 1.20.6950.6970.694321 < ∑CT / ∑CG < 41.3711.4071.418335 < ∑Index <159.8019.8369.8233410 < ∑Abbe / ∑Index <5028.59028.42528.426350.5 < CG2 / CA31 < 1.51.0061.0101.013361 < Max (CT / ET) < 31.5251.9451.964372 < CA11 / CA_min < 75.7095.4345.546380 < CA_min / ImgH < 10.5720.5950.588392 < CA_max / F < 64.7464.6304.702401 < (CA11*CT1) / (CA31*CT3) < 21.2671.2361.290.

[0314] Table 3 shows the results for the mathematical expressions 41 to 80 described above in the optical system (1000) of FIG. 1. Referring to Table 3, the optical system (1000) can satisfy at least one or two or more of the mathematical expressions 1 to 40, and at least one, two or more, or three or more of the mathematical expressions 41 to 80. In detail, it can be seen that the optical system (1000) according to the embodiment satisfies all of the mathematical expressions 1 to 80. Accordingly, the optical system (1000) can improve optical performance and optical characteristics in the center and periphery of the field of view (FOV).

[0315] Mathematical FormulaExample 1Example 2Example 3411 < CA_max / (2*ImgH) < 21.6321.6171.631421 < TD / CA_max < 31.1581.1641.155430 < F / L5R2 < 0.50.0400.0190.036440 < F / L1R1 < 0.50.0950.0740.073450 < EPD / |L6R2| < 0.50.0600.0610.060460 < EPD / L1R1 < 0.50.0420.0330.032470 < |F1 / F2| < 20.8280.8080.822481 < |F12| / F < 51.4101.3711.393491 < |F36 / F12| < 31.2081.2371.217501< |F1 / F12|<64.7054.7484.713511 < |F1 / F36| < 63.8963.8383.872521 < Aver( |F3|+ |F4|+ |F5|+ |F6|) < 63.4443.4473.434530 < |F1 / F4| < 10.2130.2110.212545 < TTL < 3012.97012.99812.970552 < ImgH2.8872.8832.88556BFL < 2.52.0572.1572.098571 < F < 201.9862.0132.00258FOV < 12070.00070.00070.000591 < TTL / CA_max < 31.3761.3941.378602 < TTL / ImgH < 74.4934.5094.495610.01 < BFL / ImgH < 10.7130.7480.727624 < TTL / BFL < 126.3056.0266.182630 < F / TTL < 10.1530.1550.154640.5 < F / BFL < 1.50.9660.9330.954650 < F / ImgH < 30.6880.6980.694661 < F / EPD < 52.2482.2472.248670 < BFL / TD < 0.30.1890.1990.193680 < EPD / Imgh / FOV < 0.20.0040.0040.0046910 < FOV / F# < 5531.14431.14731.141700 < Nd1 / Nd2 <1.51.1051.0991.109710 < Nd3 / Nd4 <1.51.1991.1991.19972(Vd3*Nd3) < (Vd1*Nd1)SatisfactorySatisfactory73(Vd2*Nd2) < (Vd1*Nd1)SatisfactorySatisfactory74(Vd3*Nd3) < (Vd2*Nd2)0.0000.0000.0007510 < (TD_LG2 / TD_LG1)*n <5020.65221.92621.7127625 < (CT_Max+CG_Max)*n < 4032.19032.14332.22077100 < (FOV*TTL) / n <200151.317151.645151.31778FOV < (TTL*n)SatisfactorySatisfactory79500 <CA_Max*TD*n < 750616.988606.759613.861800.1 < GLn / PLn < 10.50.50.5.

[0316]

[0317] FIG. 15 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. 15, a vehicle camera system according to an embodiment of the invention includes an image generating unit (11), a first information generating unit (12), a second information generating unit (21, 22, 23, 24, 25, 26), and a control unit (14). The image generating unit (11) may include at least one camera module (31) disposed in the vehicle, and may capture images of the front of the vehicle and / or the driver to generate a front image or an interior image of the vehicle. The image generating unit (11) may capture images of the surroundings of the vehicle in one or more directions as well as the front of the vehicle using the camera module (31), to generate an image of the surroundings of the vehicle. Here, the front image and the surrounding images may be digital images, and may include color images, black and white images, infrared images, etc. In addition, the front image and the surrounding images may include still images and moving images. The image generation unit (11) provides the driver image, the front image, and the surrounding image to the control unit (14). Next, the first information generation unit (12) may include at least one radar and / or camera placed in the vehicle, and detects the front of the vehicle to generate first detection information. Specifically, the first information generation unit (12) is placed in the vehicle, and detects the position and speed of vehicles located in front of the vehicle, the presence and position of pedestrians, etc. to generate the first detection information.

[0318] By using the first detection information generated by the first information generating unit (12), the distance between the own vehicle and the vehicle in front can be controlled to be maintained at a constant level, and the stability of vehicle operation can be improved in specific preset cases, such as when the driver wants to change the driving lane of the own vehicle or when backing up and parking. The first information generating unit (12) provides the first detection information to the control unit (14). The second information generating unit (21, 22, 23, 24, 25, 26) detects each side of the own vehicle based on the front image generated by the image generating unit (11) and the first detection information generated by the first information generating unit (12), and generates second detection information. Specifically, the second information generating unit (21, 22, 23, 24, 25, 26) may include at least one radar and / or camera disposed in the own vehicle, and may detect the position and speed of vehicles located on the side of the own vehicle or capture images. Here, the second information generating units (21, 22, 23, 24, 25, 26) can be placed at the front two corners, side mirrors, and rear center and rear two corners of the vehicle, respectively.

[0319] At least one information generating unit of these vehicle camera systems may be equipped with an optical system and a camera module having the same as described in the above-described embodiment(s), and may provide or process information acquired through the front, rear, each side or corner area of ​​the vehicle to a user to enable autonomous driving or to protect the vehicle and objects from surrounding safety.

[0320] The optical system of a camera module according to an embodiment of the invention can be installed in multiple units within a vehicle to enhance safety regulations, autonomous driving functions, and convenience. Furthermore, the optical system of the camera module is used as a component for controlling systems such as a Lane Keeping Assistance System (LKAS), a Lane Departure Warning System (LDWS), and a Driver Monitoring System (DMS). These vehicle camera modules can achieve stable optical performance even under ambient temperature changes and offer competitive pricing, thereby ensuring the reliability of vehicle components.

[0321] Fig. 16 is a drawing illustrating a camera module according to an embodiment applied to a mobile terminal. Referring to Fig. 16, the mobile terminal (1) may include a camera module (10) provided on the rear side. The camera module (10) may include an image capturing function. In addition, the camera module (10) may include at least one of an auto focus, a zoom function, and an OIS function. The camera module (10) may process still images or video frames obtained by an image sensor (190) in a shooting mode or a video call mode. The processed image frames may be displayed on a display unit (not shown) of the mobile terminal (1) and stored in a memory (not shown). In addition, although not shown in the drawing, the camera module may be further arranged on the front side of the mobile terminal (1). For example, the camera module (10) may include a first camera module (10A) and a second camera module (10B). At this time, at least one of the first camera module (10A) and the second camera module (10B) may include the optical system (1000) described above. Accordingly, the camera module (10) may have a slim structure and may have improved distortion and aberration characteristics. In addition, the camera module (10) may have good optical performance in the center and periphery of the field of view (FOV).

[0322] In addition, the mobile terminal (1) may further include an auto-focus device (31). The auto-focus device (31) may include an auto-focus function using a laser. The auto-focus device (31) may be mainly used in conditions where the auto-focus function using the image of the camera module (10) disclosed above is degraded, for example, in a close range of 10 m or less or in a dark environment. The auto-focus device (31) may include a light-emitting unit including a vertical cavity surface-emitting laser (VCSEL) semiconductor element, and a light-receiving unit that converts light energy into electrical energy, such as a photodiode.

[0323] In addition, the mobile terminal (1) may further include a flash module (33). The flash module (33) may include a light-emitting element that emits light internally. The flash module (33) may be operated by the camera operation of the mobile terminal or by the user's control.

[0324] The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified and implemented in other embodiments by a person having ordinary skill in the art to which the embodiments pertain. Therefore, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention. In addition, although the embodiments have been described above, these are merely examples and do not limit the present invention. Those having ordinary skill in the art to which the present invention pertains will appreciate that various modifications and applications not illustrated above are possible without departing from the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments can be modified and implemented. In addition, the differences related to such modifications and applications should be interpreted as being included in the scope of the present invention defined in the appended claims.

Claims

1. Includes first to sixth lenses arranged along the optical axis from the object toward the sensor side, The above first lens has a negative (-) refractive power on the optical axis, The object-side surface of the first lens has a convex shape on the optical axis, The object-side surface of the second lens has a convex shape on the optical axis, An optical system wherein the optical axis spacing between the second lens and the third lens is greater than the optical axis spacing between the first lens and the second lens.

2. In the first paragraph, the central thickness of the sixth lens is the thickest among the central thicknesses of the first to sixth lenses, the optical system.

3. In the second paragraph, the third lens has a positive refractive power on the optical axis, An optical system in which the third lens has a convex meniscus shape toward the object on the optical axis.

4. In the second paragraph, the central thickness of the second lens is thicker than the central thickness of the first lens, An optical system wherein the second lens has a convex meniscus shape toward the object on the optical axis.

5. In any one of paragraphs 2 to 4, An optical system in which the refractive index of the third lens is the greatest among the refractive indices of the first to sixth lenses.

6. In any one of paragraphs 1 to 4, At least two of the first to sixth lenses are made of glass, An optical system wherein the central thickness of the first lens is smaller than the central thickness of the lens disposed between the lenses made of the glass material.

7. In any one of paragraphs 1 to 4, The above first lens and the above third lens are made of glass, The above 2nd, 4th, 5th, and 6th lenses are made of plastic, optical system.

8. In any one of paragraphs 1 to 4, An optical system in which the central thickness of the fifth lens is the thinnest among the central thicknesses of the first to sixth lenses.

9. In any one of paragraphs 1 to 4, An optical system in which the effective length of the object-side surface and the sensor-side surface of each of the third to sixth lenses is smaller than the diagonal length of the image sensor.

10. A first lens group having first and second lenses arranged along the optical axis from the object toward the sensor side; A second lens group having third to sixth lenses arranged on the sensor side of the first lens group and aligned along the optical axis from the object toward the sensor side; and It includes an aperture arranged on the periphery between the third lens and the fourth lens, The power of the first lens group above has a negative (-) value, An optical system wherein the optical axis spacing between the second lens and the third lens is greater than the optical axis spacing between the first lens and the second lens.

11. In the 10th paragraph, the first lens has a negative (-) refractive power and is the largest among the focal lengths of the first to sixth lenses, The optical system wherein the sixth lens has positive (+) refractive power.

12. In paragraph 10, Any one of the lenses of the first lens group is made of glass, At least one of the lenses of the second lens group is made of glass, The above first lens has a convex meniscus shape toward the object on the optical axis, An optical system in which the effective length of the first lens is the greatest among the effective lengths of the first to sixth lenses.

13. In any one of paragraphs 10 to 12, The optical axis spacing between the second and third lenses is CG2. The central thickness of the above sixth lens is CT6, Mathematical formula: 1 < CG2 / CT6 < 3 An optical system that satisfies .

14. In any one of paragraphs 11 to 12, The third lens has the largest refractive index among the first to sixth lenses, The optical axis spacing between the second and third lenses is CG2. The optical axis spacing between the first and second lenses is CG1, Mathematical formula: 5 < GG2 / CG1 < 25 An optical system that satisfies .

15. In any one of paragraphs 10 to 12, The optical axis distance from the sensor side of the sixth lens to the upper surface of the image sensor is BFL. The central thickness of the above sixth lens is CT6, Mathematical formula: 0.5 < BFL / CT6 < 1 An optical system that satisfies .

Images