Optical system and imaging device module

Abstract

An optical system according to an embodiment of the present invention includes first to seventh lenses disposed along an optical axis, in which the first lens has a negative (-) refractive power, a combined refractive power of the second to seventh lenses is a positive (+) refractive power, a second lens among the first to seventh lenses has a minimum effective diameter, and a third lens among the first to seventh lenses has a minimum effective diameter. And the effective diameter of the first lens is maximum.

Description

Technical Field

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

[0002] Advanced driver assistance system (ADAS) is an advanced driver assistance system that assists the driver in driving. ADAS is configured to sense the situation ahead, judge the situation based on the sensing result, and control the behavior of the vehicle based on the situation judgment. For example, the ADAS sensor device detects the vehicle ahead and identifies the lane. After that, when the target lane, target speed and target ahead are determined, the vehicle's electrical stability control (ESC), engine management system (EMS), motor-driven power steering (MDPS), etc. are controlled. Representatively, ADAS can be implemented as an automatic parking system, a low-speed city driving assistance system, a blind spot warning system, etc.

[0003] Sensor devices used to detect the front situation in ADAS include GPS sensors, laser scanners, front radars, LIDAR, etc., and the most representative ADAS is a camera device used to capture the front, rear, and sides of the vehicle.

[0004] These camera devices can be set outside or inside the vehicle to detect the environment around the vehicle. In addition, these camera devices can also be set inside the vehicle to detect the conditions of the driver and passengers. For example, the camera device can shoot the driver at a position adjacent to the driver and detect the driver's health, whether the driver is drowsy, whether the driver is drinking, etc. In addition, the camera device can shoot the passenger at a position adjacent to the passenger and detect whether the passenger is sleeping, health status, etc., and provide information about the passenger to the driver.

[0005] In particular, the most important element for obtaining an image from an image pickup device is an imaging lens that forms the image. Recently, there has been an increasing interest in high performance such as high definition and high resolution, and in order to achieve this, research is being conducted on an optical system including a plurality of lenses. However, there is a problem in that when the image pickup device is exposed to a harsh environment such as high temperature, low temperature, moisture, or high humidity outside or inside a vehicle, the characteristics of the optical system change. In this case, the image pickup device has a problem in that it is difficult to uniformly obtain excellent optical characteristics and aberration characteristics.

[0006] Therefore, a new optical system and imaging device that can solve the above-mentioned problems are needed. Summary of the invention

[0007] Technical Topics

[0008] Embodiments are directed to providing an optical system and a camera module having enhanced optical characteristics.

[0009] Embodiments are directed to providing an optical system and a camera module having excellent optical performance in a low to high temperature environment.

[0010] Embodiments are directed to providing an optical system and a camera module capable of preventing or minimizing changes in optical characteristics within various temperature ranges.

[0011] Technical Solutions

[0012] In order to solve the above technical problems, an optical system according to an embodiment of the present invention includes: first to seventh lenses arranged along an optical axis, wherein the first lens has a negative (-) refractive power, the combined refractive power of the second to seventh lenses has a positive (+) refractive power, the second lens among the first to seventh lenses has the smallest effective diameter, and the first lens has the largest effective diameter.

[0013] The fourth lens, the fifth lens, and the seventh lens may be made of a plastic material, and at least one lens of the first to third lenses and the sixth lens may be made of a glass material.

[0014] Effective diameters of the sixth lens and the seventh lens may be smaller than an effective diameter of the fifth lens.

[0015] The object-side surface of the second lens may have a flat surface.

[0016] Among the first to seventh lenses, the lens having the smallest absolute value of focal length may be one lens among the third to fifth lenses.

[0017] The absolute values ​​of the focal lengths of the third to fifth lenses may satisfy the following conditional expression. <Conditional Expression> |F3|≥|F4|≥|F5| (in the above conditional expression, F3 is the focal length of the third lens, F4 is the focal length of the fourth lens, and F5 is the focal length of the fifth lens).

[0018] In order to solve the above technical problems, an optical system according to another embodiment of the present invention includes: a first lens to a seventh lens arranged along an optical axis, wherein the first lens has a negative (-) refractive power, the combined refractive power of the second lens to the seventh lens has a positive (+) refractive power, and the effective diameter of the first lens can be greater than the effective diameter of the third lens.

[0019] The optical system includes a cemented lens in which a lens having a positive (+) refractive power and a lens having a negative (−) refractive power are bonded, and the cemented lens may be formed of continuously disposed two lenses among the third to fifth lenses.

[0020] The cemented lens may be made of a plastic material, and at least one of the first lens to the third lens and the sixth lens is made of a glass material.

[0021] Among the first lens to the seventh lens, the absolute value of the focal length of the fifth lens may be the smallest, and the absolute value of the focal length of the sixth lens may be the largest.

[0022] At least one of the lens closest to the cemented lens on the object side of the cemented lens and the lens closest to the cemented lens on the sensor side of the cemented lens may have a biconvex shape.

[0023] The absolute value of the radius of curvature of the sensor-side surface of the cemented lens may be smaller than the absolute value of the radius of curvature of the object-side surface of the cemented lens.

[0024] To solve the above technical problems, an optical system according to another embodiment of the present invention includes a first lens to a seventh lens arranged along the optical axis. Among them, among the first lens to the seventh lens, the absolute value of the focal length of the sixth lens is the largest, the absolute value of the focal length of the fifth lens is the smallest, and the following conditional expression may be satisfied. <Conditional expression> 0.2 < CG1 / TTL < 0.6 (in this conditional expression, CG1 is the distance on the optical axis between the first lens and the second lens, and TTL is the distance from the object-side surface of the first lens along the optical axis to the image sensor).

[0025] The ratio of the absolute value of the focal length of the sixth lens to the absolute value of the focal length of the fifth lens may be greater than 5 times and less than 10 times.

[0026] The absolute values of the focal lengths of the third lens to the fifth lens may satisfy the following conditional expression. <Conditional expression> |F3| ≥ |F4| ≥ |F5| (in the above conditional expression, F3 is the focal length of the third lens, F4 is the focal length of the fourth lens, and F5 is the focal length of the fifth lens).

[0027] On the optical axis, among the first lens to the seventh lens, the seventh lens may have the smallest thickness, and on the optical axis, among the first lens to the seventh lens, the fourth lens may have the largest thickness.

[0028] The thickness of the second lens on the optical axis may be smaller than the thicknesses of the third lens and the fourth lens.

[0029] The first lens may have a meniscus shape convex toward the object side.

[0030] The third lens may have a biconvex shape.

[0031] The first lens, the fifth lens, and the seventh lens may have negative (−) refractive power, and the second lens, the third lens, the fourth lens, and the sixth lens may have positive (+) refractive power.

[0032] In order to solve the above technical problems, an optical system according to an embodiment of the present invention includes first to seventh lenses arranged along an optical axis, wherein the first lens has a negative (-) refractive power, the combined refractive power of the second to seventh lenses has a positive (+) refractive power, and among the first to third lenses, the effective diameter of the second lens is the smallest, and the thickness of the second lens on the optical axis is greater than the thickness of the first lens.

[0033] The fourth to seventh lenses may be made of plastic, and at least one lens of the first to third lenses may be made of glass.

[0034] Effective diameters of the sixth and seventh lenses may be smaller than that of the fifth lens, and an effective diameter of the third lens among the first to seventh lenses may be the largest.

[0035] The second lens may have a meniscus shape that is convex toward the sensor side.

[0036] Among the first to seventh lenses, the lens having the smallest absolute value of focal length may be one lens among the third to fifth lenses.

[0037] The absolute values ​​of the focal lengths of the third to fifth lenses may satisfy the following conditional expression. <Conditional Expression> |F3|≥|F4|≥|F5| (in this conditional expression, F3 is the focal length of the third lens, F4 is the focal length of the fourth lens, and F5 is the focal length of the fifth lens).

[0038] In order to solve the above technical problems, an optical system according to another embodiment of the present invention includes first to seventh lenses arranged along an optical axis, wherein the first lens has a negative (-) refractive power, effective diameters of the sixth lens and the seventh lens are smaller than the effective diameter of the fifth lens, and a thickness of the second lens on the optical axis may be greater than a thickness of the first lens.

[0039] The first lens is made of glass, and the fourth lens and the fifth lens may be made of plastic.

[0040] The optical system includes a cemented lens in which a lens having a positive (+) refractive power and a lens having a negative (-) refractive power are bonded, and at least one of a lens disposed closest to the cemented lens on an object side of the cemented lens and a lens disposed closest to the cemented lens on a sensor side of the cemented lens may have a biconvex shape.

[0041] An absolute value of a radius of curvature of a sensor-side surface of the cemented lens may be smaller than an absolute value of a radius of curvature of an object-side surface of the cemented lens.

[0042] The object side surface of the cemented lens has a convex shape, and the sensor side surface of the cemented lens may have a concave shape.

[0043] The cemented lens may include two lenses of the third to fifth lenses that are continuously disposed.

[0044] In order to solve the above technical problems, an optical system according to another embodiment of the present invention includes first to seventh lenses arranged along the optical axis, wherein, among the first to seventh lenses, the absolute value of the focal length of the second lens is the largest, the absolute value of the focal length of the fifth lens is the smallest, and the ratio of the absolute values ​​of the focal lengths of the second lens to the fifth lens may be greater than 5 times and less than 10 times.

[0045] A ratio of absolute values ​​of focal lengths of the second lens and the third lens may be greater than 2 and less than 10.

[0046] The absolute values ​​of the focal lengths of the third to fifth lenses may satisfy the following conditional expression. <Conditional Expression> |F3|≥|F4|≥|F5| (in this conditional expression, F3 is the focal length of the third lens, F4 is the focal length of the fourth lens, and F5 is the focal length of the fifth lens).

[0047] On the optical axis, the fifth lens has the smallest thickness among the first to seventh lenses, and on the optical axis, the second lens may have the largest thickness among the first to seventh lenses.

[0048] A thickness of the second lens on the optical axis may be greater than thicknesses of the third lens and the fourth lens.

[0049] Among the first to seventh lenses, an absolute value of a curvature radius of a sensor-side surface of the sixth lens may be the largest, and an absolute value of a curvature radius of a sensor-side surface of the fifth lens may be the smallest.

[0050] The third lens may have a biconvex shape.

[0051] An absolute value of a radius of curvature of an object-side surface of the third lens and an absolute value of a radius of curvature of a sensor-side surface of the third lens may be the same.

[0052] Beneficial Effects

[0053] The optical system and the camera module according to the embodiment may have enhanced optical characteristics. Specifically, in the optical system according to the embodiment, the plurality of lenses may have set thicknesses, refractive powers, and gaps from adjacent lenses. Therefore, the optical system and the camera module according to the embodiment may have enhanced MTF characteristics, aberration control characteristics, resolution characteristics, etc. within a set viewing angle range, and may have good optical performance in the edge portion of the viewing angle.

[0054] In addition, the optical system and the camera module according to the embodiment can have good optical performance in the low temperature to high temperature range (-40°C to 105°C). Specifically, the multiple lenses included in the optical system can have set materials, refractive power and refractive index. Therefore, when the refractive index of each lens changes according to the temperature change and the focal length of each lens also changes accordingly, it can be compensated by the plastic lens and the glass lens. That is, the optical system can effectively perform refractive power distribution in the low temperature to high temperature range, and can prevent or minimize the change of optical characteristics in the low temperature to high temperature range. Therefore, the optical system and the camera module according to the embodiment can maintain enhanced optical characteristics in various temperature ranges.

[0055] In addition, the optical system and the camera module according to the embodiment can meet the set viewing angle by mixing the plastic lens and the glass lens, and achieve excellent optical characteristics. Therefore, the optical system can provide a thinner vehicle camera module. Therefore, the optical system and the camera module can be provided to various applications and devices, and can have excellent optical characteristics even in a harsh temperature environment, such as when exposed to the outside of the vehicle or the inside of the vehicle under high temperatures in summer. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 1 is a side cross-sectional view of an optical system according to a first embodiment and an image pickup device module having the optical system.

[0057] Figure 2 It is used to explain the Figure 1 A side cross-sectional view showing the relationship between the nth lens and the n-1th lens.

[0058] Figure 3 It is shown Figure 1 A table of lens characteristics of an optical system.

[0059] Figure 4 It is shown Figure 1 Table of aspheric coefficients of lenses in the optical system.

[0060] Figure 5 It is shown Figure 1A table of the thickness of each lens in an optical system and the gaps between adjacent lenses.

[0061] Figure 6 It is shown Figure 1 sag values ​​of the lens surfaces of the third lens to the sixth lens in the optical system of FIG.

[0062] Figure 7 It shows that according to Figure 1 A table of chief ray angle (CRA) data at room temperature, low temperature, and high temperature for the position of the image sensor in the optical system.

[0063] Figure 8 Is to show about Figure 1 A graph of the diffraction modulation transfer function (MTF) data of an optical system at room temperature.

[0064] Fig. 9 Is to show about Figure 1 A graph of the diffraction MTF data of an optical system at low temperatures.

[0065] Fig.10 Is to show about Figure 1 A graph of the diffraction MTF data of an optical system at high temperature.

[0066] Fig.11 Is to show about Figure 1 A graph of data of aberration characteristics of an optical system at room temperature.

[0067] Fig.12 Is to show about Figure 1 A graph showing the aberration characteristics of an optical system at low temperatures.

[0068] Fig.13 Is to show about Figure 1 A graph showing data on aberration characteristics of an optical system at high temperatures.

[0069] Fig.14 is a graph showing relative illuminance according to the height of the image sensor according to the first embodiment.

[0070] Fig.15 is a cross-sectional side view of an optical system and an image pickup device module having the optical system according to a second embodiment.

[0071] Fig.16 It is used to explain the Fig.15 A cross-sectional diagram showing the relationship between the nth lens and the n-1th lens.

[0072] Fig.17 It is shown Fig.15 A table of lens characteristics of an optical system.

[0073] Fig.18 It is shown Fig.15 Table of aspheric coefficients of lenses in the optical system.

[0074] Fig.19 It is shown Fig.15 A table of the thickness of each lens in an optical system and the gaps between adjacent lenses.

[0075] Fig. 20 It is shown Fig.15 A table of sag values ​​of lens surfaces of the third lens to the sixth lens in the optical system.

[0076] Fig.21 It shows that according to Fig.15 A table of chief ray angle (CRA) data at room temperature, low temperature, and high temperature for the position of the image sensor in the optical system.

[0077] Fig. 22 Is to show about Fig.15 A graph of the diffraction modulation transfer function (MTF) data of an optical system at room temperature.

[0078] Fig.23 Is to show about Fig.15 A graph of the diffraction MTF data of an optical system at low temperatures.

[0079] Fig.24 Is to show about Fig.15 A graph of the diffraction MTF data of an optical system at high temperature.

[0080] Fig.25 Is to show about Fig.15 A graph of data of aberration characteristics of an optical system at room temperature.

[0081] Fig.26 Is to show about Fig.15 A graph showing the aberration characteristics of an optical system at low temperatures.

[0082] Fig. 27 Is to show about Fig.15 A graph showing data on aberration characteristics of an optical system at high temperatures.

[0083] Fig.28 is a graph showing relative illuminance according to the height of the image sensor according to the second embodiment.

[0084] Fig.29 is an example of a vehicle having an optical system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0085] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0086] However, the technical concept of the present invention is not limited to some embodiments to be described but may be implemented in various forms, and within the scope of the technical concept of the present invention, one or more of the constituent elements may be selectively combined or replaced between the embodiments.

[0087] In addition, unless explicitly defined and described, the terms (including technical terms and scientific terms) used in the embodiments of the present invention may be interpreted as meanings that can be generally understood by those skilled in the art, and commonly used terms such as terms defined in dictionaries may be interpreted in consideration of the meaning of the background of the relevant technology.

[0088] In addition, the terms used in the present specification are for describing the embodiments and are not intended to limit the present invention.

[0089] In this specification, unless explicitly stated in a phrase, a singular form may include a plural form, and when described as "at least one (or more than one) of A and B and C", it may include one or more of all combinations that can be combined with A, B and C.

[0090] In addition, when describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only intended to distinguish a component from other components, and these terms do not limit the nature, order, or sequence of the components.

[0091] Furthermore, when a component is described as being “connected,” “coupled” or “interconnected” to another component, the component is not only directly connected, coupled or interconnected to the other components but may also include the case where it is “connected,” “coupled” or “interconnected” due to another component between the other components.

[0092] In addition, when described as being formed or disposed “on” or “below” each component, “on” or “below” means that it includes not only a case where two components are in direct contact, but also a case where one or more other components are formed or disposed between the two components. In addition, when expressed as “on” or “below”, it may include the meaning of not only an upward direction but also a downward direction based on one component.

[0093] In the description of the present invention, "object side surface" may refer to the surface of the lens facing the object side relative to the optical axis (OA), and "sensor side surface" may refer to the surface of the lens facing the imaging surface (image sensor) relative to the optical axis. "Object side" may be "object side surface", and "sensor side surface" may be "image side". The convex surface of the lens may refer to a convex shape in the optical axis or paraxial region, and the concave surface of the lens may refer to a concave shape in the optical axis or paraxial region. The radius of curvature, the center thickness, and the optical axis gap between the lenses described in the table of lens data may refer to the numerical value on the optical axis (unit: mm). The vertical direction may refer to the direction perpendicular to the optical axis, and the end of the lens or lens surface may refer to the end of the effective area of ​​the lens through which the incident light passes. Depending on the measurement method, etc., the size of the effective diameter of the lens surface may have a measurement error of up to ±0.4mm. The paraxial region refers to a very narrow area near the optical axis, and is an area where the distance of light falling from the optical axis OA is almost 0. In the following, the meaning of the optical axis may include the center of each lens or a very narrow area near the optical axis.

[0094] like Figure 1 As shown, the optical system 1000 according to the first embodiment of the present invention may include five or more lenses. The optical system 1000 and the camera module having the optical system 1000 may be installed inside or outside the vehicle to monitor the driver or sense external objects or lanes. The material of the lens may be selected from glass or plastic, and the linear expansion coefficient of glass is less than the linear expansion coefficient of plastic. Therefore, a glass lens is used to suppress the change of the focal imaging position caused by temperature changes. However, glass lenses are more expensive than plastic lenses, and there is a problem of being difficult to meet the low-cost requirements. Therefore, the lens in the optical system 1000 needs to have a mixed configuration of a glass lens and a plastic lens. By adopting such a plastic lens, the optical system 1000 can provide reduced weight and low cost by reducing the thickness of the plastic lens, and due to the plastic lens, it is possible to provide good correction of various aberrations such as spherical aberration and chromatic aberration. In addition, the plastic lens can provide an aspherical lens, which can help minimize the distortion of the edge portion.

[0095] The optical system 1000 may include n lenses, wherein the nth lens may be the last lens adjacent to the image sensor 300, and the (n-1)th lens may be the lens closest to the last lens. n is an integer greater than or equal to 5, for example, n may be 5 to 8. The n lenses may have a ratio of plastic lenses to glass lenses in the range of 2:3 to 2:6, or in the range of 3:4 to 3:5.

[0096] The optical system 1000 may include a plurality of lens groups LG1 and LG2. Specifically, each of the plurality of lens groups LG1 and LG2 includes at least one lens. For example, the optical system 1000 may include a first lens group LG1 and a second lens group LG2 sequentially disposed along the optical axis OA from the object side toward the image sensor 300.

[0097] The number of lenses in the first lens group LG1 and the second lens group LG2 may be different from each other. The number of lenses in the second lens group LG2 may be greater than the number of lenses in the first lens group LG1, for example, greater than four times or more than five times the number of lenses in the first lens group LG1. The first lens group LG1 may include at least one lens. The first lens group LG1 may have three or less lenses. The first lens group LG1 may preferably be one lens. The second lens group LG2 may include two or more lenses. The second lens group LG2 may have four to seven lenses. The second lens group LG2 may preferably be six lenses.

[0098] The first lens group LG1 may include at least one lens made of a glass material. The first lens group LG1 may provide a lens closest to the object side as a lens made of a glass material. Such a glass material can prevent surface damage because the change in expansion and contraction of such a glass material according to the external temperature is small and the surface is not easily scratched.

[0099] As for the lens material of the second lens group LG2, at least one lens made of glass and at least one lens made of plastic may be mixed. In the second lens group LG2, at least one lens made of plastic may be provided on the sensor side instead of a lens made of glass. The second lens group LG2 may include two or more lenses made of glass, for example, 2 to 4 lenses. The second lens group LG2 may be, for example, 2 to 6 lenses. As another example, the second lens group LG2 may have one or more lenses made of plastic. The second lens group LG2 may include two or more lenses made of plastic, for example, 2 to 4 plastic lenses.

[0100] At least one lens closest to the object in the optical system 1000 may be a glass material. Three or more lenses, for example, three to five lenses, closest to the object may be glass materials. Since the rate of change of contraction and expansion of the glass lens according to temperature change is smaller than the rate of change of contraction and expansion of the plastic material according to temperature change, the glass lens may be disposed in an area adjacent to the outside of the lens barrel.

[0101] At least one lens closest to the image sensor 300 in the optical system 1000 may be a plastic material. For example, at least two lenses closest to the image sensor 300 may be a plastic material, and preferably, at least two lenses adjacent to the image sensor 300 may be a plastic material. That is, since the nth and n-1th lenses in the optical system 1000 are set as plastic lenses, various aberrations can be corrected with respect to the incident light of the image sensor 300.

[0102] In the optical system 1000, lenses made of a plastic material may be disposed continuously, and lenses made of a glass material may be disposed continuously. In the optical system 1000, lenses made of a plastic material may be disposed between lenses made of a glass material. In the optical system 1000, lenses made of a glass material may be disposed between lenses made of a plastic material.

[0103] Each of the lenses 101 to 107 may have an object side surface and a sensor side surface. In the optical system, the number of lenses having an aspherical sensor side surface and an aspherical object side surface may be greater than the number of plastic lenses. In the optical system, the number of lenses having a spherical sensor side surface and a spherical object side surface may be less than the number of lenses having aspherical surfaces on both sides. Since the optical system 1000 includes more aspherical lenses than spherical lenses, various aberrations may be corrected.

[0104] Among the lenses of the optical system 1000, the lens with the maximum refractive index can be positioned adjacent to the first lens group LG1 or the object. The maximum refractive index can be 1.7 or more. The dispersion of light incident on the lens with the maximum refractive index can be increased, and the center thickness can be made thinner than the edge thickness. In addition, since the lens with the maximum refractive index is disposed on the object side, it is easy to change the radius of curvature of the second lens and subsequent lenses, and the center thickness can be increased.

[0105] In the optical system 1000, the lens having the largest effective diameter may be disposed closest to the object side. In the optical system 1000, the lens having the largest effective diameter may be disposed at the central portion of the object side and the sensor side. The effective diameter of the lens may increase and then decrease in the process from the object side to the sensor side. The effective diameter of the lens may decrease and then increase and then decrease again in the process from the object side to the sensor side. In this way, since the light incident on the optical system 1000 is designed to move away from the optical axis and then gather back toward the optical axis, the optical system 1000 may form a stable optical path.

[0106] The effective diameter may be the diameter of the effective area where effective light is incident from each lens. The effective diameter is the length in the X and Y directions orthogonal to the optical axis, and is the average of the effective diameter on the object side surface and the effective diameter on the sensor side surface of each lens. The "diameter of the lens surface" may refer to the "effective diameter of the lens". The "diameter of the lens" may be the diameter of the entire lens including the flange portion of the lens in addition to the effective area of ​​the lens. Although Figure 1 and Figure 2 The flange of the lens is not shown in the figure, but the flange may be a portion protruding perpendicularly to the optical axis from the side surface of the lens so that the lens is connected to the lens barrel. Effective light may not be incident on the flange. A spacer may be additionally provided between the flanges of different lenses so that the lens is connected to the lens barrel.

[0107] Each of the lenses 101 to 107 may include an effective area and an ineffective area. The effective area may be an area through which light incident on each lens passes. That is, the effective area may be defined as an effective area or an effective diameter through which incident light is refracted to achieve optical properties. The ineffective area may be arranged around the periphery of the effective area. The ineffective area may be an area where effective light is not incident from a plurality of lenses. That is, the ineffective area may be an area that is unrelated to optical properties. In addition, the end of the ineffective area may be an area fixed to a lens barrel or the like that houses the lens.

[0108] In the optical system 1000, the total track length (TTL) can be greater than 2 times of ImgH, for example, greater than 4 times and less than 12 times. The total track length (TTL) is the distance from the center of the object side surface of the first lens on the optical axis OA to the upper surface of the image sensor 300. ImgH is the distance from the optical axis OA to the diagonal end of the image sensor 300 or 1 / 2 of the maximum diagonal length. In the optical system 1000, the effective focal length (EFL) is set to 10 mm or more, and the viewing angle (FOV) is set to less than 45 degrees, so that the optical system can be set in a vehicle camera module as a standard optical system. For example, the optical system and the camera module according to the embodiment can be applied to an advanced driver assistance system (ADAS) camera device set inside or outside a vehicle.

[0109] The TTL / ImgH condition of the optical system 1000 may be 5 or more and 7.5 or more, for example, 6 or more and 7 or less. By setting the value of TTL / ImgH to 5 times or more and 7.5 times or less, the optical system 1000 can provide a vehicle lens optical system. The total number of lenses of the first lens group LG1 and the second lens group LG2 is 8 or less. Therefore, the optical system 1000 can provide an image that is not exaggerated or distorted.

[0110] In the optical system 1000, the effective diameter of at least one plastic lens may be smaller than the length of the image sensor 300. The effective diameter is the diameter or length of the effective area into which light is incident. The length of the image sensor 300 is the maximum length of a diagonal line in a direction orthogonal to the optical axis OA. In the optical system 1000, the number of lenses having an effective diameter greater than the length of the image sensor 300 may be 50% or more or 60% or more, and the number of lenses having an effective diameter less than the length of the image sensor 300 may be less than 50% or less than 40%.

[0111] At least one cemented lens 145 may be included in the optical system 1000. The cemented lens 145 is a lens in which at least two lenses having different refractive powers are bonded, and the distance between the two lenses may be less than 0.01 mm. The cemented lens 145 may be a lens in which two lenses having different focal lengths are bonded. The bonding of the two lenses may be bonded with an adhesive. The effective diameter of at least one or all lenses disposed on the object side relative to the cemented lens 145 may be greater than the length of the image sensor 300. The effective diameter of at least one lens disposed on the sensor side relative to the cemented lens 145 may be less than the length of the image sensor 300. In addition, the object side lens 104 of the cemented lens 145 may be greater than the length of the image sensor 300, and the sensor side lens 105 may be greater than the length of the image sensor 300.

[0112] The lens between the cemented lens 145 and the first lens 101 may be made of glass or plastic. The lens disposed between the cemented lens 145 and the image sensor 300 may be made of plastic. The lens between the cemented lens 145 and the first lens 101 may be a lens that is spherical on both sides or a lens that is aspherical on both sides. The lens disposed between the cemented lens 145 and the image sensor 300 may be a lens that is aspherical on both sides. The two surfaces are the object side surface and the sensor side surface. Therefore, by arranging the aspherical lens between the cemented lens 145 and the image sensor 300, the optical performance can be improved by correcting the curvature aberration and the chromatic aberration.

[0113] On the optical axis OA, 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 between the first lens group LG1 and the second lens group LG2 may be an optical axis gap between the sensor side surface of the lens closest to the sensor side among the lenses in the first lens group LG1 and the object side of the lens closest to the object side surface among the lenses in the second lens group LG2. The optical axis gap between the first lens group LG1 and the second lens group LG2 may be three to five times or less of the optical axis distance of the first lens group LG1, for example, may be in the range of four to five times of the optical axis distance of the first lens group LG1.

[0114] The optical axis distance between the first lens group LG1 and the second lens group LG2 may be equal to or less than twice the optical axis distance of the second lens group LG2, for example, in the range of 1.8 to 1.2 times. The optical axis distance of the second lens group LG2 is the optical axis distance between the object side of the lens closest to the object side surface of the second lens group LG2 and the sensor side surface of the lens closest to the image sensor 300.

[0115] Here, two surfaces facing each other among the lens surfaces of the first lens group LG1 and the second lens group LG2, for example, the sensor side surface of the object side lens may be concave, and the object side surface of the sensor side lens may be a flat surface. That is, the sensor side surface closest to the sensor side surface in the first lens group LG1 may be concave, and the object side surface closest to the object side surface in the second lens group LG2 may be a flat surface. The first lens group LG1 may diffuse light incident through the object side, and the second lens group LG2 may refract light diffused by the first lens group LG1 into the area of ​​the image sensor 300.

[0116] The first lens group LG1 has a negative (-) refractive power, and the second lens group LG2 may have a positive (+) refractive power. The lens closest to the object side among the lenses of the first lens group LG1 has a negative (-) refractive power, and the lens closest to the sensor side among the lenses of the second lens group LG2 may have a negative (-) refractive power. When the focal length is expressed in absolute values, the focal length of the first lens group LG1 may be greater than the focal length of the second lens group LG2, for example, in a range of 5 to 10 times greater than the focal length of the second lens group LG2. The effective focal length (EFL) of the optical system 1000 may be less than the absolute value of the focal length of the first lens group LG1. The effective focal length (EFL) of the optical system 1000 may be less than the absolute value of the focal length of the first lens group LG1, and may be greater than the absolute value of the focal length of the second lens group LG2.

[0117] The number of lenses having positive (+) refractive power in the optical system 1000 may be equal to or greater than the number of lenses having negative (-) refractive power. The number of lenses having negative (-) refractive power may be 50% or more of the total number of lenses. The average refractive index of lenses having positive (+) refractive power may be greater than the average refractive index of lenses having negative (-) refractive power. Therefore, the dispersion value of lenses having negative (-) refractive power may be smaller than the dispersion value of lenses having positive (+) refractive power.

[0118] The lens unit 100 may be a mixture of glass lenses and plastic lenses. The number of plastic lenses may be 60% or less of the total number of lenses, and may be in the range of 30% to 60% or 30% to 50%. Therefore, when more plastic lenses are provided in the camera module, the weight of the camera module may be reduced, and due to the plastic material, the camera module is easy to polish and process, is resistant to external impacts, has high price competitiveness, and is easy to obtain materials. In addition, various aberrations may be corrected by the plastic lens, so that degradation of optical performance may be prevented.

[0119] The first embodiment of the present invention can reduce the weight of the camera device module by further mixing a plastic lens into the optical system 1000, can provide lower manufacturing costs, can suppress the degradation of optical properties due to temperature changes, can allow various types of plastic lenses to replace glass lenses, and can facilitate polishing and processing of lens surfaces such as aspherical surfaces or free-form surfaces.

[0120] The lens unit 100 may include a lens of a first material and a lens of a second material disposed along the optical axis OA. The first material may be a glass material, and the second material may be a plastic material. The lens of the first material may be disposed between the lenses of the second material. The lens of the second material may be disposed between the lenses of the first material.

[0121] The lens unit 100 may include a first material lens having an aspherical surface along the optical axis OA, a first material lens having a spherical surface, and a second material lens having an aspherical surface. The first material may be a glass material, and the second material may be a plastic material. The first material lens having a spherical surface may be arranged between the second material lens having an aspherical surface. The second material lens may be arranged between the first material lens having an aspherical surface and the first material lens having a spherical surface.

[0122] The effective diameter of the lens closest to the object side in the lens unit 100 may be larger than the effective diameter of the lens closest to the image sensor 300. Therefore, the brightness of the optical system can be controlled. The effective diameter may be the average effective diameter of the object side surface and the sensor side surface of each lens. By controlling the size of the effective diameter of each lens, the optical system 1000 can control incident light to compensate for the degradation of optical characteristics due to resolution and temperature changes, improve chromatic aberration control characteristics, and improve the vignetting characteristics of the optical system 1000.

[0123] The lens unit 100 may include a first lens 101 , a second lens 102 , a third lens 103 , a fourth lens 104 , a fifth lens 105 , a sixth lens 106 , and a seventh lens 107 aligned along an optical axis from an object side to a sensor side.

[0124] Within the lens unit 100, the plastic lens can be a cemented lens or can be at least one lens adjacent to the image sensor. The focal length (F6) of the sixth lens 106 can be the largest within the optical system and can be greater than the focal length (absolute value) of the second lens group LG2. That is, the condition |FLG2| < F6 can be satisfied.

[0125] Within the lens unit 100, there can be three or more lenses having an effective diameter greater than the average effective diameter of the plastic lens, such as four or more lenses. When the average effective diameter of the plastic lens is PLca_Aver and the average effective diameter of the glass lens is GLca_Aver, the condition PLca_Aver < GLca_Aver can be satisfied. In addition, the condition 1 < GLca_Aver / PLca_Aver < 1.5 can be satisfied. In addition, the relationship between the length of the image sensor 300 and the average effective diameter PLca_Aver of the plastic lens can satisfy the condition 1 ≤ PLca_Aver / (ImgH*2) < 1.5. In addition, the relationship between the average effective diameter of the glass lens and the length of the image sensor 300 can satisfy the condition 1.1 < GLca_Aver / (ImgH*2) < 1.5. The difference between the maximum length of the image sensor 300 and the effective diameter of the plastic lens can be small. Therefore, by arranging the plastic lens with a small effective diameter adjacent to the image sensor 300, the plastic lens can disperse the color from the central portion to the edge portion of the image sensor 300.

[0126] The average effective diameter of the glass material can be 10 mm or more, for example, within the range of 10 mm to 15 mm. The average effective diameter of the plastic material can be 8 mm or more, for example, within the range of 8 mm to 12 mm. The lens having the smallest effective diameter can be made of plastic, and the lens having the largest effective diameter can be made of glass. The smallest effective diameter in the lens unit 100 can be within the range of 7 mm to 10 mm, and the largest effective diameter can be within the range of 11 mm to 18 mm. The plastic lens is designed to have an effective diameter smaller than that of the glass lens and is arranged not to contact the lens barrel, thereby minimizing the change in optical performance caused by temperature change. In addition, the optical system 1000 can improve the resolution and chromatic aberration control characteristics by controlling the incident light, and can improve the vignetting characteristics of the optical system 1000.

[0127] The optical system 1000 or the imaging device module can include the image sensor 300. The image sensor 300 can detect light and convert the light into an electrical signal. The image sensor 300 can detect the light passing through the lens unit 100 in sequence. The image sensor 300 can include elements capable of detecting incident light, such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS).

[0128] Here, the length of the image sensor 300 is the maximum length in the diagonal direction orthogonal to the optical axis OA, and may be smaller than the effective diameter of the lens closest to the object in the first lens group LG1, and larger than the effective diameter of the lens closest to the sensor in the second lens group LG2. Here, the number of lenses having an effective diameter greater than the length of the image sensor 300 may be 4 to 6, and the number of lenses having an effective diameter less than the length of the image sensor 300 may be 1 to 3.

[0129] The optical system 1000 or the camera module may include a filter 500. The filter 500 may be disposed between the second lens group LG2 and the image sensor 300. The filter 500 may be disposed between the lens closest to the sensor side among the lenses of the lens unit 100 and the image sensor 300. For example, the filter 500 may be disposed between the nth lens and the image sensor 300.

[0130] The cover glass 400 is disposed between the filter 500 and the image sensor 300, protects the upper portion of the image sensor 192, and can prevent the reliability of the image sensor 192 from being deteriorated. The cover glass 400 may be removed. The cover glass 400 may be a protective glass.

[0131] The filter 500 may include an infrared filter or an infrared cut filter (IR cut). The filter 500 may allow light of a set wavelength band to pass through, and filter light of a different wavelength band. When the filter 500 includes an infrared filter, it may prevent radiant heat emitted from external light from being transmitted to the image sensor 300. In addition, the filter 500 may allow visible light to pass through and reflect infrared light.

[0132] The optical system 1000 according to the first embodiment may include an aperture (stop). The aperture can adjust the amount of light incident on the optical system 1000. In a lens disposed between an object and an aperture, the effective diameter of the lens surface tends to increase from the object side to the aperture. In a lens surface disposed between the aperture and a sensor, the effective diameter of the lens surface tends to decrease from the aperture to the sensor side. The tendency of the effective diameter of the lens surface to increase or decrease does not only mean a case where the effective diameter of the lens surface increases or decreases. For example, it also includes a case where the effective diameter of the lens surface increases from the aperture to the sensor side and then decreases.

[0133] The aperture may be set at a set position. For example, the aperture may be set on the periphery of the object side surface or the sensor side surface of the lens closest to the object side among the lenses of the second lens group LG2. Different from this, the aperture may be set on the periphery of the object side surface or the sensor side surface of the object side lens of the first lens group LG1. Different from this, at least one lens selected from a plurality of lenses may be used as the aperture. Specifically, the object side surface or the sensor side surface of a lens selected from the lenses of the optical system 1000 may be used as the aperture for controlling the amount of light.

[0134] In the optical system 1000 of the first embodiment, the sum of the refractive indexes of the lenses of the lens unit 100 may be 8 or more, for example, in the range of 8 to 15, and the average value of the refractive index may be in the range of 1.58 to 1.7. The sum of the Abbe numbers of each of the lenses may be 300 or more, for example, in the range of 310 to 350, and the average value of the Abbe numbers may be 50 or less, for example, in the range of 35 to 47. The sum of the center thicknesses of the entire lenses may be 18 mm or more, for example, in the range of 20 mm to 25 mm, and the average value of the center thicknesses may be in the range of 2.8 mm to 3.5 mm. The sum of the center gaps between the lenses on the optical axis OA may be 10 mm or more, for example, in the range of 10 mm to 18 mm, and may be less than the sum of the center thicknesses of the lenses. In addition, the average value of the effective diameters of each of the lens surfaces S1 to S14 of the lens unit 100 may be set in the range of 8 mm or more, for example, in the range of 8 mm to 15 mm.

[0135] In the optical system according to the first embodiment of the present invention, the viewing angle (diagonal) may be 50 degrees or less, for example, in the range of 20 to 50 degrees. The F number of the optical system or camera module may be 2.4 or less, for example, in the range of 1.4 to 2.4 or in the range of 1.5 to 1.8. In the optical system according to the embodiment of the present invention, the maximum viewing angle (diagonal) may be 50 degrees or less, for example, in the range of 20 to 50 degrees. The vehicle optical system may have a horizontal viewing angle (FOV_H) in the Y-axis direction, which may be greater than 20 degrees and less than 40 degrees, for example, in the range of 25 to 35 degrees. In addition, the vertical viewing angle is set to an angle less than the horizontal viewing angle, and may be 20 degrees or less, for example, in the range of 10 to 20 degrees. At this time, the sensor length in the horizontal direction (Y) may be 8.064 mm ± 0.5 mm, and the sensor height in the vertical direction (X) may be 4.54 mm ± 0.5 mm. The horizontal field of view (FOV_H) is the field of view relative to the horizontal length of the sensor. Therefore, it is possible to suppress the focus imaging position from changing due to temperature changes, and provide a vehicle camera device in which various aberrations are well corrected.

[0136] Since the first embodiment is an optical system applied to a vehicle camera device, even if it is designed to use a plastic lens and a glass lens together, the first lens 101 can be set to a glass material. This is because the glass material has the advantages of being scratch-resistant and insensitive to external temperature compared to the plastic material. The first lens 101 can be a glass molded lens having an aspherical surface and made of a glass material. The glass molded lens can be manufactured by placing an optical glass ingot in a mold having an aspherical shape and through a heating and compression process.

[0137] In order to more effectively prevent scratches caused by foreign matter or objects set inside the vehicle, a glass lens can be used as the first lens 101, and the object side surface of the first lens 101 can have a gently curved shape so that it does not contact the external structure. In this way, scratches caused by contact with the external structure can be minimized. In order to perform driver monitoring, front / rear shooting or lane detection of the vehicle while the vehicle is driving, and detection of objects falling around the vehicle, the viewing angle can be greater than 20 degrees and less than 40 degrees, for example, it can be in the range of 25 degrees to 35 degrees. The horizontal viewing angle can be a preset angle of an advanced driver assistance system (ADAD).

[0138] The optical system 1000 according to the first embodiment may further include a reflective member 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 lens. The optical system according to the embodiment will be described in detail below.

[0139] An optical system according to a first embodiment of the present invention will be described.

[0140] Figure 1 is a side cross-sectional view of an optical system and an image pickup device module having the optical system according to a first embodiment; Figure 2 It is used to explain the Figure 1 A side cross-sectional view showing the relationship between the n-th lens and the n-1-th lens; Figure 3 It is shown Figure 1 A table of lens characteristics of an optical system; Figure 4 It is shown Figure 1 Table of aspheric coefficients of lenses in optical systems; Figure 5 It is shown Figure 1 A table of the thickness of each lens in the optical system and the gaps between adjacent lenses; Figure 6 It is shown Figure 1 A table of sag values ​​of lens surfaces of the third lens to the sixth lens in the optical system; Figure 7 It shows that according to Figure 1A table of chief ray angle (CRA) data at room temperature, low temperature, and high temperature for a position of an image sensor in an optical system; Figure 8 Is to show about Figure 1 A graph of the diffraction modulation transfer function (MTF) data of the optical system at room temperature; Fig. 9 Is to show about Figure 1 A graph showing the diffraction MTF data of an optical system at low temperature; Fig.10 Is to show about Figure 1 A graph showing the diffraction MTF data of an optical system at high temperature; Fig.11 Is to show about Figure 1 A graph showing data of aberration characteristics of an optical system at room temperature; Fig.12 Is to show about Figure 1 A graph showing data of aberration characteristics of an optical system at low temperatures; Fig.13 Is to show about Figure 1 A graph of data of aberration characteristics of an optical system at high temperature; and Fig.14 is a graph showing relative illuminance according to the height of the image sensor according to the first embodiment.

[0141] Reference Figures 1 to 4 , the optical system 1000 includes a lens unit 100, and the lens unit 100 includes first to seventh lenses 101 to 107. The first to seventh lenses 101 to 107 may be sequentially disposed along an optical axis OA of the optical system 1000. Light corresponding to information about an object may pass through the first to seventh lenses 101 to 107 and the filter 500, and may be incident on the image sensor 300.

[0142] The first lens 101 is the lens closest to the object side in the first lens group LG1. The seventh lens 107 is the lens closest to the image sensor 107 in the second lens group LG2 or the lens unit 100. The first lens 101 may be the first lens group LG1, and the second to seventh lenses 102, 103, 104, 105, 106, and 107 may be the second lens group LG2. An aperture may be provided on the periphery of the object side or sensor side surface of the first lens 101 or on the periphery of the object side or sensor side surface of the second lens 102. For example, an aperture (stop) may be provided on the periphery of the object side surface of the second lens 102.

[0143] The first lens 101 may be disposed closest to the object side. The first lens 101 may be disposed farthest from the sensor side. The first lens 101 may have a negative (-) refractive power on the optical axis OA. The first lens 101 may include a plastic material or a glass material, and may be, for example, a glass material. The first lens 101 made of a glass material may reduce changes in a center position, a radius of curvature, etc. due to temperature changes according to the surrounding environment, and may protect the incident side surface of the optical system 1000.

[0144] The first surface S1 on the object side of the first lens 101 may be convex with respect to the optical axis, and the second surface S2 on the sensor side may be concave. The first lens 101 may have a meniscus shape convex toward the object side. The first lens 101 is made of glass and may have an aspherical surface. The aspherical coefficients of the first surface S1 and the second surface S2 may be set to Figure 4 The first lens 101 may be manufactured as a lens having an aspherical surface by injection molding a glass material. The first lens 101 may be a glass molded lens having an aspherical surface and made of a glass material. The glass molded lens may be manufactured by placing an optical glass ingot in a mold having an aspherical shape and by a heating and compression process.

[0145] The effective radius (r11) of the first lens 101 may be greater than that of the plastic lens. Different from this, at least one of the object-side surface and the sensor-side surface of the first lens 101 may have a free surface, that is, a non-rotationally symmetric surface.

[0146] The effective diameter of the sensor-side surface of the second lens 102 may be designed to be smaller than the effective diameter of the object-side surface according to the shape of the lens surface of the first lens 101. The first surface S1 of the first lens 101 may be set to have no critical point from the optical axis OA to the end (i.e., edge) of the effective area. The second surface S2 of the first lens 101 may be set to have no critical point.

[0147] The refractive index (n1) of the first lens 101 may satisfy the condition n1>1.7 or n1>1.72. Since the refractive index (n1) of the first lens 101 is the largest within the lens unit 100, the radius of curvature of the first lens 101 and the second lens 102 may be increased, and lens manufacturing may become easy. If the refractive index (n1) of the first lens 101 is less than the condition, the lens surface must be formed to be sharply concave or convex to increase the refractive power of the first lens 101 and the second lens 102. In this case, the manufacture of the lens is not easy, the defect rate of the lens increases, and this may lead to a decrease in yield.

[0148] The second lens 102 may be disposed second on the object side. The second lens 102 may be disposed sixth on the sensor side. The second lens 102 may be disposed between the first lens 101 and the third lens 103. The second lens 102 may have a negative (-) refractive power on the optical axis OA. The second lens 102 may include a plastic or glass material. For example, the second lens 102 may be formed of a glass material.

[0149] Relative to the optical axis OA, the object-side third surface S3 of the second lens 102 may be a flat surface, and the sensor-side fourth surface S4 may be convex. The object-side third surface S3 of the second lens 102 may be a smooth curved surface. Although it is difficult to form a curved surface when manufacturing a lens made of a glass material, since the object-side third surface S3 of the second lens 102 is formed in a flat plate, it may be easy to manufacture. The second lens 102 is made of a glass material and may be a spherical surface. At least one or all of the third surface S3 and the fourth surface S4 may be spherical. At least one or all of the third surface S3 and the fourth surface S4 may be set to have no critical point from the optical axis OA to the end of the effective area.

[0150] The aperture (stop) may be provided along the periphery of the third surface S3 on the object side of the second lens 102. The combined focal length of the second lens 102 to the seventh lens 107 provided on the sensor side of the aperture may have a positive (+) value, and the TTL may be reduced within the viewing angle range, thereby achieving miniaturization of the optical system. Therefore, a decrease in the yield of the optical system according to weight may be prevented, and production efficiency may be improved. In addition, the optical system may be miniaturized by reducing the TTL at a horizontal viewing angle (FOV_H) of 25 to 36 degrees.

[0151] The third lens 103 may be disposed at the third from the object side. The third lens 103 may be disposed at the fifth from the sensor side. The third lens 103 may be disposed between the second lens 102 and the fourth lens 104. The third lens 103 may have a positive (+) refractive power on the optical axis OA. The third lens 103 may include a plastic or glass material. For example, the third lens 103 may be set to a glass material.

[0152] The object-side fifth surface S5 of the third lens 103 may be convex relative to the optical axis, and the sensor-side sixth surface S6 may be convex. The third lens 103 may have a shape in which both sides are convex relative to the optical axis OA. Since both sides of the third lens 103 are set to be convex, the TTL and the number of lenses of the optical system can be minimized, and light can be refracted effectively. The third lens 103 may be made of glass and may be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 may be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 may be set to have no critical point from the optical axis OA to the end of the effective area.

[0153] The fourth lens 104 may be disposed at the fourth from the object side. The fourth lens 104 may be disposed at the fourth from the sensor side. The fourth lens 104 may be disposed between the third lens 103 and the fifth lens 105. The fourth lens 104 may have a positive (+) or negative (-) refractive power on the optical axis OA. The fourth lens 104 may have a positive (+) refractive power. The fourth lens 104 may have a positive (+) refractive power different from the refractive power of the fifth lens 105. The fourth lens 104 may include a plastic or glass material. For example, the fourth lens 104 may be disposed with a plastic material. The fourth lens 104 may be disposed with the same material as the fifth lens 105.

[0154] The object-side seventh surface S7 of the fourth lens 104 may be convex with respect to the optical axis, and the sensor-side eighth surface S8 may be concave. The fourth lens 104 may have a meniscus shape convex toward the object side. The fourth lens 104 is made of a plastic material and may have an aspherical surface. At least one or both of the seventh surface S7 and the eighth surface S8 may be spherical. For example, the object-side seventh surface S7 may be aspherical, and the sensor-side eighth surface S8 may be spherical. The aspherical coefficient of the seventh surface S7 may be set to Figure 4 The seventh surface S7 and the eighth surface S8 may be arranged to have no critical point from the optical axis OA to the end of the effective area.

[0155] The fifth lens 105 may be disposed at the fifth from the object side. The fifth lens 105 may be disposed at the third from the sensor side. The fifth lens 105 may be disposed between the fourth lens 104 and the sixth lens 106. The fifth lens 105 may have a positive (+) or negative (-) refractive power on the optical axis OA. The fifth lens 105 may have a negative (-) refractive power. The fifth lens 105 may have a negative (-) refractive power different from the refractive power of the fourth lens 104. The fifth lens 105 may include a plastic material or a glass material. For example, the fifth lens 105 may be disposed with a plastic material. The fifth lens 105 may be disposed with the same material as the fourth lens 104.

[0156] The fifth lens 105 may have a convex ninth surface S9 on the object side and a concave tenth surface S10 on the sensor side relative to the optical axis OA. The fifth lens 105 may have a meniscus shape with the object side convex relative to the optical axis OA. The fifth lens 105 may be made of a plastic material and may have an aspherical surface. At least one of the ninth surface S9 and the tenth surface S10 may be an aspherical surface. For example, the object-side ninth surface S9 of the fifth lens 105 may be a spherical surface, and the sensor-side tenth surface S10 of the fifth lens 105 may be an aspherical surface. The aspherical coefficient of the tenth surface S10 may be set to Figure 4 At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 105 may be disposed to have no critical point from the optical axis OA to the end of the effective area.

[0157] The fourth lens 104 and the fifth lens 105 may be bonded. The bonding surface between the fourth lens 104 and the fifth lens 105 may be defined as an eighth surface S8. The eighth surface S8 may be the same surface as the ninth surface of the fifth lens 105. The object side surface of the cemented lens 145 may be convex, and the sensor side surface may be concave. The gap between the fourth lens 104 and the fifth lens 105 may be less than 0.01 mm, and may be bonded with an adhesive. From the optical axis OA to the end of the effective area, the gap between the fourth lens 104 and the fifth lens 105 may be less than 0.01 mm. The fourth lens 104 and the fifth lens 105 may have opposite refractive powers. The bonding surface S8 of the cemented lens 145 may be spherical, and the non-bonding surfaces S7 and S10 of the cemented lens 145 may be aspherical.

[0158] The value of the curvature radius of the bonding surface S8 of the cemented lens 145 may be greater than 30. For example, the value of the curvature radius of the bonding surface S8 of the cemented lens 145 may be greater than 50. The bonding surface S8 of the cemented lens 145 may form a gentle shape. In this way, the bonding process of the fourth lens 104 and the fifth lens 105 forming the cemented lens 145 is favorable, and the bonding holding strength can be improved.

[0159] The product of the refractive power of the object-side fourth lens 104 and the refractive power of the sensor-side fifth lens 105 of the cemented lens 145 can be less than 0, and the product of the focal length of the object-side fourth lens 104 and the focal length of the sensor-side fifth lens 105 of the cemented lens 145 can be less than 0. Therefore, the aberration characteristics of the optical system can be improved. When the refractive powers of the two lenses of the cemented lens 145 are the same, the improvement of aberrations is limited.

[0160] Relative to the cemented lens 145, the third lens 103 on the object side and the sixth lens 106 on the sensor side may have positive refractive powers. Accordingly, the third lens 103, the cemented lens 145, and the sixth lens 106 may refract some incident light in the optical axis direction and correct chromatic aberration with each other. Relative to the cemented lens 145, the focal length of the third lens 103 provided on the object side may be smaller than the focal length of the sixth lens 106 provided on the sensor side. Relative to the cemented lens 145, the dioptric power of the third lens 103 provided on the object side may be larger than the dioptric power of the sixth lens 106 provided on the sensor side.

[0161] The effective diameter of the fourth lens 104 may be larger than the diagonal length of the image sensor 300. The effective diameter of the fourth lens 104 is the average of the effective diameters of the seventh surface S7 and the eighth surface S8, and may be larger than the diagonal length of the image sensor 300. The effective diameter of the fifth lens 105 may be smaller than the effective diameter of the fourth lens 104 and larger than the diagonal length of the image sensor 300.

[0162] When the effective diameter of the seventh surface S7 of the fourth lens 104 is CA_L4S1 and the effective diameter of the eighth surface S8 is CA_L4S2, the effective diameters of the seventh surface S7 and the eighth surface S8 may satisfy the condition 1 < CA_L4S1 / CA_L4S2 < 1.5. When the effective diameter of the ninth surface S9 of the fifth lens 105 is CA_L5S1 and the effective diameter of the tenth surface S10 is CA_L5S2, the effective diameters of the ninth surface and the tenth surface may satisfy the condition 1 < CA_L5S1 / CA_L5S2 < 1.5.

[0163] The cemented lens 145 is joined with plastic lenses having different refractive indices and has an aspherical refractive surface. When the lens positioned on the sensor side of the cemented lens 145 is a spherical lens or a glass lens, aspherical aberration can be compensated. Since the position of the cemented lens 145 is within any two consecutive lenses among the third to sixth lenses that are intermediate or after intermediate within the lens unit 100, chromatic aberration correction can be more efficient.

[0164] The sixth lens 106 may be set as the sixth from the object side. The sixth lens 106 may be set as the second from the sensor side. The sixth lens 106 may be provided between the fifth lens 106 and the seventh lens 107. The sixth lens 106 may have a positive (+) or negative (-) refractive power on the optical axis OA. The sixth lens 106 may have a positive (+) refractive power. The sixth lens 106 may include a plastic or glass material. For example, the sixth lens 106 may be set as a glass material.

[0165] The sixth lens 106 may have a convex eleventh surface S11 on the object side and a concave twelfth surface S12 on the sensor side relative to the optical axis OA. The sixth lens 106 may have a meniscus shape convex from the optical axis OA toward the object side. At least one or both of the eleventh surface S11 and the twelfth surface S12 may be spherical. For example, both the eleventh surface S11 and the twelfth surface S12 may be spherical.

[0166] The eleventh surface S11 of the sixth lens 106 may be disposed to have no critical point from the optical axis OA to the end of the effective area. The twelfth surface S12 may be disposed to have no at least one critical point from the optical axis OA to the end of the effective area.

[0167] The seventh lens 107 may be arranged to be closest to the sensor side. The seventh lens 107 may be arranged to be farthest from the object side. The seventh lens 107 may have a positive (+) or negative (-) refractive power on the optical axis OA. The seventh lens 107 may have a negative (-) refractive power. The seventh lens 107 may include a plastic or glass material. For example, the seventh lens 107 may be made of a plastic material.

[0168] The object-side 13th surface S13 of the seventh lens 107 may be convex on the optical axis, and the sensor-side 14th surface S14 may be concave. The seventh lens 107 may have a meniscus shape convex toward the object side. At least one of the 13th surface S13 and the 14th surface S14 may be aspherical. For example, both the 13th surface S13 and the 14th surface S14 may be aspherical. The aspherical coefficients of the 13th surface S13 and the 14th surface S14 may be set to Figure 4 S1 and S2 of L7.

[0169] The thirteenth surface S13 of the seventh lens 107 may have a critical point from the optical axis OA to the end of the effective area. When the thirteenth surface S13 has a critical point, it may be located at 50% or more of the effective radius (r71) from the optical axis OA, or in the range of 52% to 70%, or in the range of 53% to 60%. When the fourteenth surface S14 has a critical point, it may be located at 70% or more of the effective radius (r72) from the optical axis OA, or in the range of 70% to 90%, or in the range of 75% to 85%.

[0170] The seventh lens 107 may be a plastic lens that is closest to the image sensor 300. Furthermore, by arranging one or more plastic lenses adjacent to the image sensor 300, aberrations such as spherical aberration and chromatic aberration may be improved by a lens surface having an aspherical surface, and the influence on the resolution may be controlled. Furthermore, by arranging a plastic lens as a lens adjacent to the image sensor 300, the plastic lens may be insensitive to assembly tolerances compared to a glass lens. That is, insensitivity to assembly tolerances means that even when assembly is performed with slight differences compared to the design during assembly, the optical performance is not significantly affected. Furthermore, by setting one lens 107 adjacent to the image sensor 300 to a plastic material, the optical performance may be improved by a lens surface having an aspherical surface, and, for example, aberration characteristics may be improved and resolution degradation may be prevented.

[0171] At least one or both of the 13th surface S13 and the 14th surface S14 of the seventh lens 107 may have a critical point. The 13th surface S13 of the seventh lens 107 may have a first critical point P1 from the optical axis OA to the end of the effective area. The first critical point P1 of the 13th surface S13 may be located at 55% or more of the effective radius from the optical axis OA, or in the range of 55% to 75%, or in the range of 60% to 70%. The first critical point of the 13th surface S13 may be located at a distance of 2 mm or more from the optical axis OA, for example, in the range of 2.1 mm to 2.5 mm, or in the range of 2.2 mm to 2.3 mm. As another example, the 13th surface S13 may be set to have no critical point. The 13th surface S13 having the first critical point P1 may refract incident light to the central portion and the edge portion, and improve aberrations. The first critical point P1 and the second critical point P2 are points where the sign of the gradient value changes from positive (+) to negative (-) or from negative (-) to positive (+) with respect to the optical axis OA and the direction perpendicular to the optical axis OA, and may refer to a point where the gradient value is 0. In addition, the first critical point P1 and the second critical point P2 may be points where the gradient value of a tangent line passing through the lens surface increases and then decreases, or may be points where it decreases and then increases.

[0172] The fourteenth surface S14 of the seventh lens 107 may have at least one second critical point P2 from the optical axis OA to the end of the effective area. The second critical point P2 of the fourteenth surface S14 may be located at a distance of 60% or more of the effective radius (r72) from the optical axis OA, or in a range of 60% to 80%, or in a range of 65% to 75%. The second critical point P2 of the fourteenth surface S14 may be located at a distance of 2.9 mm or more from the optical axis OA, for example, in a range of 2.9 mm to 3.9 mm, or in a range of 3.1 mm to 3.7 mm. Therefore, the second critical point P2 is set closer to the edge than the first critical point P1, so that the seventh lens 107 can refract the incident light to the edge portion of the image sensor 300.

[0173] The average effective radius of the 13th surface S13 and the 14th surface S14 of the 7th lens 107 is set to be smaller than ImgH (half the diagonal length of the ImgH image sensor 300), so that light can be refracted to the edge portion of the image sensor 300 through the 14th surface S14 having the second critical point P2.

[0174] like Figure 2 and Figure 6 As shown, sag41 represents the height from the center of the seventh surface S7 of the fourth lens 104 to the lens surface in the direction (X, Y) orthogonal to the optical axis OA, and the maximum value of sag41 may be the height at the edge of the seventh surface S5.

[0175] Sag42 represents the height from the center of the eighth surface S8 of the fourth lens 104 to the lens surface in the direction (X, Y) orthogonal to the optical axis OA, and the maximum value of sag42 may be the height at the edge of the eighth surface S8. Sag52 represents the height from the center of the ninth surface S9 of the fifth lens 105 to the lens surface in the direction (X, Y) orthogonal to the optical axis OA, and the maximum value of sag52 may be the height at the edge of the ninth surface S9.

[0176] Sag61 represents the height from the center of the eleventh surface S11 of the sixth lens 106 to the lens surface in the direction (X, Y) orthogonal to the optical axis OA, and the maximum value of sag61 may be the height at the edge of the eleventh surface S11. Sag62 represents the height from the center of the twelfth surface S12 of the sixth lens 106 to the lens surface in the direction (X, Y) orthogonal to the optical axis OA, and the maximum sag value is the height at the edge.

[0177] The maximum sag value can meet the following conditions.

[0178] Can meet the condition Max_sag51 <Max_sag52<Max_sag41。

[0179] The difference between Max_sag52 and Max_sag61 may be less than 1. By setting the sag value between these adjacent glass and plastic lenses, light loss between the glass and plastic lenses may be reduced.

[0180] exist Figure 6 , when the sag value is a positive value, the lens surface is located on the sensor side relative to the straight line orthogonal to the optical axis OA, and when the sag value is a negative value, the lens surface is located on the object side relative to the straight line orthogonal to the optical axis OA. In addition, when comparing the object side surface and the sensor side surface of each lens, the object side surface and the sensor side surface of the seventh lens 107 can be surfaces with the smallest difference between the maximum sag value and the minimum sag value. This is because the distance between the object side surface and the sensor side surface of the seventh lens 107 is constant, and the average value of the curvature radius can be greater than the average value of the curvature radius of the other lenses.

[0181] like Figure 1 and Figure 2 As shown, the center thickness of the first lens 101 to the seventh lens 107 is represented by CT1 to CT7, the edge thickness at the end of the effective area of ​​each lens is represented by ET1 to ET7, the center gap between two adjacent lenses is represented by CG1 to CG6, and the edge gap between the edges of each lens is represented by EG1 to EG6. Here, the center thickness of the cemented lens 145 is CT34, and the edge thickness is represented by ET45.

[0182] Reference Figure 2 , the back focal length (BFL) is the optical axis distance from the image sensor 300 to the center of the last lens. Figure 1 , TTL is an optical axis distance from the center of the first surface S1 of the first lens 101 to the upper surface of the image sensor 300 .

[0183] Figure 3 yes Figure 1 Examples of lens data for an optical system of an embodiment of the present invention. Figure 3 As shown, the curvature radius of the optical axis OA of the first to seventh lenses 101, 102, 103, 104, 105, 106 and 107, the thickness of the lenses, the center distance between the lenses, the refractive index at the d line, the Abbe number and the size of the clear aperture CA can be set.

[0184] like Figure 4As shown, in the lenses of the lens unit 100 in the present embodiment, the lens surfaces of the first lens 101, the second lens 102, the sixth lens 106, and the seventh lens 107 may include an aspheric surface having a 30th order aspheric coefficient. For example, the first lens 101, the second lens 102, the sixth lens 106, and the seventh lens 107 may include a lens surface having a 30th order aspheric coefficient. As described above, since the aspheric surface having a 30th order aspheric coefficient (a value other than "0") can significantly change the aspheric shape of the edge portion, the optical performance of the edge portion of the field of view (FOV) can be well corrected.

[0185] like Figure 5 As shown, the thicknesses T1 to T7 of the first to seventh lenses 101, 102, 103, 104, 105, 106, and 107 and the gaps G1 to G6 between two adjacent lenses may be set. Figure 5 As shown, the thickness T1 to T7 of each lens in the Y-axis direction may be indicated at intervals of 0.1 mm or 0.2 mm or more, and the gaps G1 to G6 between each lens may be indicated at intervals of 0.1 mm or 0.2 mm or more.

[0186] Reference Figure 3 and Figure 5 , the object-side third surface S3 of the second lens 102 may be flat and have an infinite radius of curvature. When comparing the absolute value of the radius of curvature of each lens, among the lens surfaces having curvature, the radius of curvature of the object-side 13th surface S13 of the seventh lens 107 on the optical axis OA may be the largest, and the radius of curvature of the sensor-side 10th surface S10 of the fifth lens 105 may be the smallest among the lenses. Among the lens surfaces having curvature, the difference between the maximum radius of curvature and the minimum radius of curvature may be 50 times or more, for example, 52 to 58 times.

[0187] Based on the optical axis, when the center thickness of the lens is described, the center thickness (CT4) of the fourth lens 104 is the largest among the lenses, and the center thickness (CT7) of the seventh lens 107 is the smallest among the lenses. The difference between the maximum center thickness and the minimum center thickness among the lenses may be in the range of 1.5 mm or more and 2.5 mm or less.

[0188] When explaining the center gap (CG) between the lenses, the center gap (CG1) between the first lens 101 and the second lens 102 may be the largest, and the center gap between the second lens 102 and the third lens 103 may be the smallest. Here, the minimum center gap does not include the bonding surface of the cemented lens 145. In the spaced-apart lenses, the difference between the maximum center gap and the minimum center gap may be 10 mm or more, for example, in the range of 10 mm to 15 mm.

[0189] When explaining about the effective diameter, the lens with the largest effective diameter may be disposed between the first lens 101 closest to the object and the seventh lens 107 closest to the image sensor 300. The lens with the largest effective diameter may be a glass lens. The lens with the largest effective diameter may be disposed closest to the object side. The lens with the largest effective diameter may be the first lens 101. Here, the effective diameter is an average value of the effective diameters of the object side surface and the sensor side surface of each lens. The lens surface with the largest effective diameter may be the object side first surface S1 of the first lens 101.

[0190] The lens with the smallest effective diameter may be any one of the plastic lenses and may be disposed, for example, closest to the image sensor 300. The lens with the smallest effective diameter may be the seventh lens 107. The lens surface with the smallest effective diameter may be the thirteenth surface S13 of the seventh lens 107.

[0191] The effective diameter of each of the first to fourth lenses 101 to 104 adjacent to the object side may be greater than the effective diameters of the fifth, sixth, and seventh lenses 105, 106, and 107 adjacent to the sensor side. The effective diameters of the first to fourth lenses 101 to 104 may be greater than the diagonal length of the image sensor 300. The average effective diameter of the sixth and seventh lenses 106 and 107 may be less than the diagonal length of the image sensor 300. Therefore, light incident through a plurality of lenses aligned along the optical axis may be guided to the image sensor 300.

[0192] In describing the refractive index, the refractive index of the first lens 101 is the largest among the lenses and may be greater than 1.7, for example, greater than 1.72. The refractive index of the fourth lens 104 is the smallest among the lenses and may be less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index may be 0.2 or greater. By providing a high refractive index lens made of glass closest to the object, and providing one of the lens adjacent to the glass lens and the cemented lens as a low refractive index lens made of plastic, the incident efficiency can be improved, and the refractive power between the glass lens and the plastic lens can be adjusted to guide light to the image sensor 300.

[0193] When comparing the Abbe numbers, the Abbe numbers of the second lens 102 and the third lens 103 are the largest among the lenses and may be 60 or more. The Abbe numbers of the fifth lens 105 and the seventh lens 107 are the smallest among the lenses and may be 25 or less. The difference between the maximum refractive index and the minimum Abbe number may be 40 or more. By maximizing the Abbe numbers of the second lens 102 and the third lens 103 adjacent to the cemented lens 145 and setting the Abbe numbers of the fifth lens 105 and the seventh lens 107 adjacent to the image sensor 300 to the minimum, the dispersion of light traveling between the glass lenses can be controlled, and the dispersion between the glass and plastic lenses can be increased to guide the light to the image sensor 300.

[0194] The focal lengths (F1, F5, F7) of the first lens 101, the fifth lens 105, and the seventh lens 107 may have a negative (-) sign. The first lens 101, the fifth lens 105, and the seventh lens 107 may have a negative (-) refractive power. The focal lengths (F2, F3, F4, and F6) of the second lens 102, the third lens 103, the fourth lens 104, and the sixth lens 106 may have a positive (+) sign. The second lens 102, the third lens 103, the fourth lens 104, and the sixth lens 106 may have a positive (+) refractive power. The second lens 102, the third lens 103, and the fourth lens 104 having a positive (+) refractive power may be disposed on the sensor side of the first lens 101 having a negative (-) refractive power. By doing so, light incident on the object side may move away from the optical axis direction and then be gathered again in the optical axis direction, thereby forming a stable optical path.

[0195] In addition, the first lens 101 and the second lens 102 as lenses disposed adjacently may satisfy the following conditions.

[0196] Condition 1: The refractive index of the lens with positive refractive power < the refractive index of the lens with negative refractive power

[0197] Condition 2: Dispersion value of lens with positive refractive power > dispersion value of lens with negative refractive power

[0198] Here, in the glass lens, the second lens 102 has a positive refractive power and the first lens 101 has a negative refractive power, so according to conditions 1 and 2, the refractive index of the second lens is smaller than the refractive index of the first lens, and the dispersion value of the second lens is larger than the dispersion value of the first lens. Chromatic aberration occurring in the glass lens can be corrected by the glass lens. In addition, since the first lens 101 and the second lens 102 as glass lenses arranged in series satisfy the refractive index difference of 0.1 or more and 0.16 or less and the Abbe number difference of 20 or more and 60 or less, the chromatic aberration occurring in the glass lens can be compensated by the glass lens.

[0199] The optical system has chromatic aberration, and chromatic aberration is corrected by using a cemented lens or two lenses arranged in series. As the temperature changes from low to high, the lens shrinks and expands repeatedly. Since the lens characteristics of lenses of the same material change by the same amount according to temperature changes, it is effective to correct chromatic aberration between lenses of the same material even if the temperature changes.

[0200] Therefore, in the first embodiment of the present invention, the first lens 101 and the second lens 102 are used to correct chromatic aberration occurring in a glass lens, and the fourth lens 104 and the fifth lens 105 are used to correct chromatic aberration occurring in a plastic lens.

[0201] When the fourth lens 104 and the fifth lens 105 as a cemented lens satisfy the refractive index difference of 0.1 or more and 0.15 or less and the Abbe number difference of 20 or more and 60 or less, chromatic aberration occurring in the plastic lens can be compensated by the plastic lens. The refractive index difference is rounded to the third decimal place, and the Abbe number difference is rounded to the first decimal place to compare these values.

[0202] Furthermore, by arranging a glass lens having a relatively high Abbe number on the object side of a plastic lens, dispersion can be reduced by the glass lens, and dispersion can be increased by the plastic lens.

[0203] When comparing focal lengths in absolute values, the focal length of the sixth lens 106 is the largest among the lenses and may be 80 or more, or 100 or more. The sixth lens 106 may have a maximum focal length and a minimum refractive power. The focal length of the fifth lens 105 is the smallest among the lenses and may be 20 or less, or 15 or less. Among the lenses excluding the cemented lens 145, the lens with the smallest focal length may be the third lens 103. The third lens 103 may be 30 or less, or 25 or less. The difference between the maximum focal length and the minimum focal length may be 50 or more, or 80 or more. Therefore, the optical system may have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. within the set viewing angle range, and may have good optical performance in the edge portion of the viewing angle.

[0204] There is a critical point on the sensor side of the seventh lens 107. The critical point is a point where the trend of the sag value changes. That is, a point where the sag value increases and then decreases, or a point where the sag value decreases and then increases. Figure 6, it can be seen that the critical point exists on the sensor side of the seventh lens 107, between the point 1.8 mm apart and the point 2.0 mm apart in the direction perpendicular to the optical axis. On the sensor side of the seventh lens 107, the sag value increases to the point 1.9 mm apart in the direction perpendicular to the optical axis, and then decreases from the point 1.9 mm apart to the point 4.6 mm apart in the direction perpendicular to the optical axis. When the critical point exists on the sensor side of the seventh lens 107, that is, on the sensor side of the last lens, that is, on the lens surface closest to the sensor, TTL can be reduced, thereby facilitating miniaturization and lightness of the optical system.

[0205] The thickness (T1) of the first lens 101 may be 1 or more times, for example, 1 to 1.2 times, of the difference between the maximum thickness and the minimum thickness, and the center thickness (CT1) may be the minimum value, and the edge thickness (ET1) may be the maximum value. The thickness (T2) of the second lens 102 may be such that the maximum thickness is in the range of 1 to 1.3 times of the minimum thickness. The second lens 102 may have a maximum center thickness (CT2) and a minimum edge thickness (ET2). The thickness (T3) of the third lens 103 may be the maximum at the center and the minimum at the edge, and the maximum thickness is in the range of 1.5 to 2 times of the minimum thickness. The thickness (T4) of the fourth lens 104 may be the maximum at the center and the minimum at the edge, and the maximum thickness is in the range of 1.8 to 2.2 times of the minimum thickness. The thickness (T5) of the fifth lens 105 may be the minimum at the center and the maximum at the edge, and the maximum thickness is in the range of 1.2 to 1.7 times of the minimum thickness. The thickness (T6) of the sixth lens 106 may be maximum at the center and minimum at the edge, and the maximum thickness may be in the range of 1.0 to 1.3 times the minimum thickness. The thickness (T7) of the seventh lens 107 may be minimum at the center and maximum at the edge, and the maximum thickness may be in the range of 1 to 1.2 times the minimum thickness.

[0206] The center thickness (CT45) of the cemented lens 145 may be greater than the edge thickness (ET45). The center thickness (CT45) of the cemented lens 145 is the distance from the center of the object-side seventh surface S7 of the fourth lens 104 to the center of the tenth surface S10 of the fifth lens 105, and the edge thickness (ET45) is the distance from the end of the effective area of ​​the seventh surface S7 to the tenth surface S10 along the optical axis direction. The maximum thickness of the cemented lens 145 is at the center portion, the minimum thickness is at the edge portion, and the maximum thickness may be in the range of 1 to 1.2 times the minimum thickness.

[0207] Among the gaps (G1-G6) between the lenses, the first gap (G1) between the first lens 101 and the second lens 102 may be the largest at the center portion and the smallest at the edge portion. The second gap (G2) between the second lens 102 and the third lens 103 may be the largest at the edge portion and the smallest at the center portion. The third gap (G3) between the third lens 103 and the fourth lens 104 may be the largest at the edge portion and the smallest at the center portion. The fifth gap (G5) between the fifth lens 105 and the sixth lens 106 may be the largest at the center portion and the smallest at the edge portion. The sixth gap (G6) between the sixth lens 106 and the seventh lens 107 may be the largest at the center portion and the smallest at the edge portion.

[0208] like Figure 7 As shown, in Figure 1 In the optical system and camera module of the present invention, the chief ray angle (CRA) at 1 field (i.e., the end of the diagonal length of the image sensor) can be 10 degrees or more, for example, in the range of 10 to 35 degrees or 10 to 25 degrees. In addition, the difference in the chief ray angle from low temperature (-40 degrees) to high temperature (95 degrees) can be 1 degree or less. Therefore, even if the temperature changes from low temperature to high temperature, the difference in the chief ray angle is not large, and stable optical performance can be achieved.

[0209] like Fig.14 As shown, the graph showing the relative illumination according to the image height in the optical system according to the first embodiment shows that the relative illumination is 70% or more, for example, 75% or more, from the center to the diagonal end of the image sensor. That is, it can be seen that there is almost no difference in the relative illumination (zoom positions 1, 2, and 3) according to room temperature, low temperature, and high temperature up to 4.5 mm from the optical axis.

[0210] Figures 8 to 10 It is shown Figure 1 Graphs of diffraction modulation transfer functions (MTFs) at room temperature, low temperature, and high temperature in an optical system of FIG. 1 and FIG. 2 are graphs showing modulation according to spatial frequency. Figures 8 to 10 As shown, in the first embodiment of the present invention, the deviation of the MTF at low or high temperature relative to room temperature may be less than 10%, ie, 7% or less.

[0211] Figure 11 to Figure 12 It is shown Figure 1 Graphs of aberration characteristics of an optical system at room temperature, low temperature, and high temperature. Figures 11 to 13 This is a graph measuring spherical aberration (longitudinal spherical aberration), astigmatism field curve, and distortion from left to right in the aberration graph. Figures 11 to 13In FIG. 1 , the X-axis may represent the focal length (mm) and the distortion (%), and the Y-axis may represent the height of the image. In addition, the graph of spherical aberration is a graph of light with wavelengths of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph of astigmatism and distortion is a graph of light with wavelengths of about 546 nm. Figures 11 to 13 In the aberration diagram, it can be seen that the closer each curve at room temperature, low temperature, and high temperature is to the Y-axis, the better the aberration correction function is. It can be seen that the measured values ​​of the optical system 1000 according to the first embodiment are close to the Y-axis in almost all areas. That is, the optical system 1000 according to the first embodiment has improved resolution not only in the central part of the field of view (FOV) but also in the edge part and can have good optical performance. Here, the low temperature is -20 degrees or lower, for example, in the range of -20 degrees to -40 degrees, the room temperature is in the range of 22 degrees ±5 degrees, or in the range of 18 degrees to 27 degrees, and the high temperature can be in the range of 85 degrees or higher, for example, in the range of 85 degrees to 105 degrees. Therefore, it can be seen that Figures 11 to 13 The decrease in brightness ratio (modulation) from low temperature to high temperature is less than 10%, for example 5% or less, or hardly changes.

[0212] Table 1 compares the changes in optical properties such as EFL, BFL, F number (F#), TTL and field of view (FOV) at room temperature, low temperature and high temperature in the optical system according to the first embodiment of the present invention, and it can be seen that the rate of change of the optical properties at low temperature is 5% or less, for example, 3% or less relative to room temperature, and it can be seen that the rate of change of the optical properties at low temperature is 5% or less, for example, 3% or less relative to room temperature.

[0213] [Table 1]

[0214]

[0215]

[0216] Therefore, as shown in Table 1, it can be seen that the change in optical characteristics (e.g., the rate of change of effective focal length (EFL), TTL, BFL, F number, and field of view (FOV)) according to the temperature change from low temperature to high temperature is 10% or less, that is, 5% or less, for example, in the range of 0 to 5%. This makes it possible to design temperature compensation for plastic lenses even when at least one or two or more plastic lenses are used, thereby preventing the reliability of optical characteristics from being reduced.

[0217] The optical system of the first embodiment disclosed above can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only in the central portion but also in the peripheral portion of the field of view (FOV).

[0218] Table 2 shows the terms in the above mathematical formula in the optical system 1000 of the first embodiment, including the total track length (TTL) (mm), the back focal length (BFL), the effective focal length (F) (mm), ImgH (mm), the effective diameter (CA) (mm), the thickness (mm), TTL (mm), the optical axis distance TD from the first surface S1 to the fourteenth surface S14 (mm), the focal length of each of the first to seventh lenses (F1, F2, F3, F4, F5, F6 and F7) (mm), the sum of the refractive index, the sum of the Abbe number, the sum of the thickness (mm), the sum of the gaps between adjacent lenses, the effective diameter characteristics, the sum of the refractive index of the glass lenses, the sum of the refractive index of the plastic material, the angle of view (FOV) (degrees), the edge thickness (ET), the focal length of the first lens group and the second lens group, the F number, etc.

[0219] [Table 2]

[0220]

[0221]

[0222] like Fig.15 As shown, the optical system 1500 according to the second embodiment of the present invention may include five or more lenses. The optical system 1500 and the camera module having the optical system 1500 may be installed inside or outside the vehicle to monitor the driver or sense external objects or lanes. The material of the lens may be selected from glass or plastic, and the linear expansion coefficient of the glass material is less than the linear expansion coefficient of the plastic material. Therefore, a glass lens is used to suppress the change of the focal imaging position caused by temperature changes. However, glass lenses are more expensive than plastic lenses, and there is a problem that it is difficult to meet the low-cost requirements. Therefore, the lens in the optical system 1500 needs to have a mixed configuration of glass lenses and plastic lenses. By adopting such a plastic lens, the optical system 1500 can provide reduced weight and low cost by reducing the thickness of the plastic lens, and through the plastic lens, good correction of various aberrations such as spherical aberration and chromatic aberration can be achieved. In addition, the plastic lens can provide an aspherical lens, which can help minimize the distortion of the edge portion.

[0223] The optical system 1500 may include n lenses, wherein the nth lens may be the last lens adjacent to the image sensor 300, and the (n-1)th lens may be the lens closest to the last lens. n is an integer greater than or equal to 5, for example, 5 to 8. The n lenses may have a ratio of glass lenses to plastic lenses in the range of 2:3 to 2:6, or in the range of 3:4 to 3:5.

[0224] The optical system 1500 may include a plurality of lens groups LG1 and LG2. Specifically, each of the plurality of lens groups LG1 and LG2 includes at least one lens. For example, the optical system 1500 may include a first lens group LG1 and a second lens group LG2 sequentially disposed along the optical axis OA from the object side toward the image sensor 300.

[0225] The number of lenses of each of the first lens group LG1 and the second lens group LG2 may be different. The number of lenses of the second lens group LG2 may be greater than the number of lenses of the first lens group LG1, for example, greater than four times or greater than five times the number of lenses of the first lens group LG1. The first lens group LG1 may include at least one lens. The first lens group LG1 may have three or less lenses. The first lens group LG1 may preferably include one lens. The second lens group LG2 may include two or more lenses. The second lens group LG2 may include four to seven lenses. The second lens group LG2 may preferably include six lenses.

[0226] The first lens group LG1 may include at least one lens made of glass. The first lens group LG1 may provide a lens closest to the object side as a lens made of glass. Such a glass material has a small amount of expansion and contraction change due to external temperature changes, and the surface is not easily scratched, so surface damage can be prevented.

[0227] The lens material of the second lens group LG2 may be a mixture of at least one glass lens and at least one plastic lens. In the second lens group LG2, at least one plastic lens may be arranged on the sensor side relative to the glass lens. The second lens group LG2 may include two or more glass lenses, for example, two to four glass lenses. The second lens group LG2 may include, for example, two to six lenses. As another example, the second lens group LG2 may have one or more plastic lenses. The second lens group LG2 may include two or more plastic lenses, for example, two to four plastic lenses.

[0228] At least one lens closest to the object in the optical system 1500 may be made of glass. Three or more lenses closest to the object, for example, three to five lenses, may be made of glass. Since the shrinkage and expansion rate of a lens made of glass due to temperature changes is smaller than the shrinkage and expansion rate of a lens made of plastic due to temperature changes, the lens made of glass may be disposed in an area adjacent to the outside of the lens barrel.

[0229] At least one lens closest to the image sensor 300 in the optical system 1500 may be made of plastic. For example, at least two lenses closest to the image sensor 300 may be made of plastic, and preferably, at least two lenses closest to the image sensor 300 may be made of plastic. That is, since the nth and (n-1)th lenses in the optical system 1500 are set as plastic lenses, various aberrations can be corrected for incident light of the image sensor 300.

[0230] In the optical system 1500, lenses made of plastic material may be arranged in sequence, and lenses made of glass material may be arranged in sequence. In the optical system 1500, lenses made of plastic material may be arranged between lenses made of glass material. In the optical system 1500, lenses made of glass material may be arranged between lenses made of plastic material.

[0231] Each of the lenses 201 to 207 may have an object side and a sensor side. The number of lenses having aspherical sensor side surfaces and aspherical object side surfaces in the optical system may be greater than the number of plastic lenses. The number of lenses having spherical sensor side surfaces and spherical object side surfaces in the optical system may be less than that of double-sided aspherical lenses. Since the optical system 1500 has more aspherical lenses than spherical lenses, various aberrations may be corrected.

[0232] Among the lenses of the optical system 1500, the lens having the maximum refractive index may be positioned adjacent to the first lens group LG1 or the object. The maximum refractive index may be 1.8 or greater. The dispersion of light incident on the lens having the maximum refractive index may be increased, and the center thickness may be made thinner than the edge thickness. In addition, since the lens having the maximum refractive index is positioned on the object side, it is easy to change the radius of curvature of the second lens and subsequent lenses, and the center thickness may be increased.

[0233] In the optical system 1500, a lens having a maximum effective diameter may be disposed at a central portion of the object side and the sensor side. The effective diameter of the lens may increase and then decrease when moving from the object side to the sensor side. The effective diameter of the lens may decrease and then increase and then decrease again when moving from the object side to the sensor side. By doing so, since the light incident on the optical system 1500 is designed to move away from the optical axis and then converge back to the optical axis, the optical system 1500 may form a stable optical path.

[0234] The effective diameter may be the diameter of the effective area of ​​effective light incident from each lens. The effective diameter is the length in the direction (X, Y) orthogonal to the optical axis, and is the average of the effective diameter on the object side surface and the effective diameter on the sensor side surface of each lens. The "diameter of the lens surface" may refer to the "effective diameter of the lens". The "diameter of the lens" may be the diameter of the entire lens including the flange portion of the lens in addition to the effective area of ​​the lens. Although Fig.15 and Fig.16 The flange of the lens is not shown in the figure, but the flange may be a portion protruding perpendicularly to the optical axis from the side surface of the lens so that the lens is connected to the lens barrel. Effective light may not be incident on the flange. A spacer may be additionally provided between the flanges of different lenses so that the lens is connected to the lens barrel.

[0235] Each of the lenses 201 to 207 may include an effective area and an ineffective area. The effective area may be an area through which light incident on each lens passes. That is, the effective area may be defined as an effective area or an effective diameter through which incident light is refracted to achieve optical properties. The ineffective area may be arranged around the periphery of the effective area. The ineffective area may be an area where effective light is not incident from a plurality of lenses. That is, the ineffective area may be an area that is unrelated to optical properties. In addition, the end of the ineffective area may be an area fixed to a lens barrel or the like that houses the lens.

[0236] In the optical system 1500, the total track length (TTL) can be greater than 2 times of ImgH, for example, greater than 4 times and less than 12 times. The total track length (TTL) is the distance from the center of the object side surface of the first lens on the optical axis OA to the upper surface of the image sensor 300. ImgH is the distance from the optical axis OA to the diagonal end of the image sensor 300 or 1 / 2 of the maximum diagonal length. In the optical system 1500, the effective focal length (EFL) is set to 10 mm or more, and the viewing angle (FOV) is set to less than 45 degrees, so that the optical system can be set in a vehicle camera module as a standard optical system. For example, the optical system and the camera module according to the embodiment can be applied to a camera of an advanced driver assistance system (ADAS) set inside or outside a vehicle.

[0237] The TTL / ImgH condition of the optical system 1500 may be 5 or more and 7.5 or more, for example, 6 or more and 7.5 or less. By setting the value of TTL / ImgH to 5 times or more and 7.5 times or less, the optical system 1500 can provide a vehicle lens optical system. The total number of lenses of the first lens group LG1 and the second lens group LG2 is 8 or less. Therefore, the optical system 1500 can provide an image that is not exaggerated or distorted.

[0238] The effective diameter of at least one plastic lens in the optical system 1500 may be smaller than the length of the image sensor 300. The effective diameter is the diameter or length of the effective area where light is incident. The length of the image sensor 300 is the maximum length of a diagonal line in a direction orthogonal to the optical axis OA. In the optical system 1500, the number of lenses having an effective diameter greater than the length of the image sensor 300 may be 50% or more or 60% or more, and the number of lenses having an effective diameter less than the length of the image sensor 300 may be less than 50% or less than 40%.

[0239] At least one cemented lens 245 may be included in the optical system 1500. The cemented lens 245 may be a lens in which at least two lenses having different refractive powers are bonded, and a gap between the two lenses may be less than 0.01 mm. The cemented lens 245 may be a lens in which two lenses having different focal lengths are bonded. The bonding of the two lenses may be bonded using an adhesive. The effective diameter of at least one lens or all lenses disposed on the object side relative to the cemented lens 245 may be greater than the length of the image sensor 300. The effective diameter of at least one lens disposed on the sensor side relative to the cemented lens 245 may be less than the length of the image sensor 300. In addition, in the cemented lens 245, the object side lens 203 may be greater than the length of the image sensor 300, and the sensor side lens 204 may be greater than the length of the image sensor 300.

[0240] The lens between the cemented lens 245 and the first lens 201 may be made of glass or plastic. The lens disposed between the cemented lens 245 and the image sensor 300 may be made of plastic. The lens between the cemented lens 245 and the first lens 201 may be a lens that is spherical on both sides or a lens that is aspherical on both sides. The lens disposed between the cemented lens 245 and the image sensor 300 may be a lens that is aspherical on both sides. The two sides are the object side and the sensor side. Therefore, by arranging the aspherical lens between the cemented lens 245 and the image sensor 300, curvature aberration and chromatic aberration may be corrected, thereby improving optical performance.

[0241] On the optical axis OA, 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 between the first lens group LG1 and the second lens group LG2 may be an optical axis gap between the sensor side of the lens closest to the sensor side among the lenses in the first lens group LG1 and the object side of the lens closest to the object side among the lenses in the second lens group LG2. The optical axis gap between the first lens group LG1 and the second lens group LG2 may be 1 times or less of the optical axis distance of the first lens group LG1, and, for example, may be in the range of 0.1 to 1 times of the optical axis distance of the first lens group LG1.

[0242] The optical axis distance between the first lens group LG1 and the second lens group LG2 may be 0.2 times or less of the optical axis distance of the second lens group LG2, and may be, for example, in the range of 0.01 times to 0.2 times. The optical axis distance of the second lens group LG2 is the optical axis distance between the object-side surface of the lens closest to the object side of the second lens group LG2 and the sensor-side surface of the lens closest to the image sensor 300.

[0243] Here, two surfaces facing each other among the lens surfaces of the first lens group LG1 and the second lens group LG2, for example, the sensor side surface of the object side lens may be concave, and the object side surface of the sensor side lens may be concave. That is, the sensor side surface closest to the sensor side in the first lens group LG1 may be concave, and the object side surface closest to the object side in the second lens group LG2 may be concave. The first lens group LG1 may diffuse light incident through the object side, and the second lens group LG2 may refract light diffused by the first lens group LG1 into the area of ​​the image sensor 300.

[0244] The first lens group LG1 may have a negative (-) refractive power, and the second lens group LG2 may have a positive (+) refractive power. Among the lenses of the first lens group LG1, the lens closest to the object side may have a negative (-) refractive power, and among the lenses of the second lens group LG2, the lens closest to the sensor side may have a negative (-) refractive power. When the focal length is expressed in absolute values, the focal length of the first lens group LG1 may be greater than the focal length of the second lens group LG2, for example, 5 times or greater, for example, in the range of 5 to 15 times. The effective focal length (EFL) of the optical system 1500 may be less than the absolute value of the focal length of the first lens group LG1. The effective focal length (EFL) of the optical system 1500 may be less than the absolute value of the focal length of the first lens group LG1 and greater than the absolute value of the focal length of the second lens group LG2.

[0245] The number of lenses having positive (+) refractive power in the optical system 1500 may be equal to or greater than the number of lenses having negative (-) refractive power. The number of lenses having positive (+) refractive power may be 50% or more of the total number of lenses. The average refractive index of lenses having positive (+) refractive power may be greater than the average refractive index of lenses having negative (-) refractive power. Therefore, the dispersion value of lenses having negative (-) refractive power may be greater than the dispersion value of lenses having positive (+) refractive power.

[0246] The lens unit 200 may be a mixture of a glass lens and a plastic lens. The number of plastic lenses may be 60% or more of the total number of lenses, and may be in the range of 40% to 85% or 60% to 80%. Therefore, when more plastic lenses are provided in the camera module, the weight of the camera module may be reduced, and due to the plastic material, the camera module is easy to polish and process, is resistant to external impact, has high price competitiveness, and is easy to obtain materials. In addition, various aberrations may be corrected by the plastic lens, so that degradation of optical performance may be prevented.

[0247] Embodiments of the present invention can reduce the weight of the camera device module by further mixing plastic lenses into the optical system 1500, provide lower manufacturing costs, suppress degradation of optical properties due to temperature changes, enable various types of plastic lenses to replace glass lenses, and facilitate polishing and processing of lens surfaces (such as aspheric surfaces or free-form surfaces).

[0248] The lens unit 200 may include a lens of a first material and a lens of a second material spaced along the optical axis OA. The first material may be a glass material, and the second material may be a plastic material. The lens of the first material may be disposed between the lenses of the second material. The lens of the second material may be disposed between the lenses of the first material.

[0249] The lens unit 200 may include a first material lens having an aspherical surface along an optical axis (OA), a first material lens having a spherical surface, and a second material lens having an aspherical surface. The first material may be a glass material, and the second material may be a plastic material. The lens of the first material having a spherical surface may be disposed between the second material lens having an aspherical surface. The lens of the second material may be disposed between the first material lens having an aspherical surface and the first material lens having a spherical surface.

[0250] The effective diameter of the lens closest to the object side in the lens unit 200 may be larger than the effective diameter of the lens closest to the image sensor 300. Therefore, the brightness of the optical system can be controlled. The effective diameter may be an average effective diameter of the object side and the sensor side of each lens. By controlling the size of the effective diameter of each lens, the optical system 1500 can control incident light to compensate for degradation of optical characteristics due to resolution and temperature changes, improve chromatic aberration control characteristics, and improve vignetting characteristics of the optical system 1500.

[0251] The lens unit 200 may include a first lens 201 , a second lens 202 , a third lens 203 , a fourth lens 204 , a fifth lens 205 , a sixth lens 206 , and a seventh lens 207 aligned along an optical axis from an object side to a sensor side.

[0252] In the lens unit 200, when the focal length is an absolute value, the focal length of the lens closest to the object may be greater than the focal length of the plastic lens. Here, the plastic lens may be at least one lens disposed on the sensor side of the cemented lens or at least one lens adjacent to the image sensor.

[0253] The lens unit 200 may be provided in a camera module having an inner barrel on one side or the entire inner surface of a lens barrel. The lens unit 200 may be provided in a camera module having a plurality of inner barrels around different lenses of the lens barrel. The lens unit 200 may be provided in a camera module having a first inner barrel in contact with the outer surface of at least one lens of the lens barrel and a second inner barrel in contact with the outer surface of at least one lens. The lens unit 200 may be provided in a camera module having a plurality of inner barrels, each of which is provided between the outer surface of at least one lens or two or more lenses and the lens barrel. The lens unit 200 may be provided in a camera module in which a plurality of inner barrels have a material different from that of the lens barrel.

[0254] Among the lenses constituting the lens unit 200, at least some of the lenses made of glass can be disposed in the lens barrel, and at least some of the lenses made of plastic can be disposed in the inner lens barrel provided within the lens barrel. By doing so, the optical system 1500 can maintain the resolution according to temperature changes. The lens unit 200 can be disposed in the imaging device module having different barrels so as to minimize the decentration of the lenses (e.g., plastic lenses) that expand according to temperature changes. The lens barrel in which the lens unit 200 is disposed has a plurality of inner lens barrels within the lens barrel, thereby maintaining the resolution of the optical system according to temperature changes and suppressing the deformation of the lenses. Therefore, the effective diameter of at least some of the lenses made of glass included in the lens unit 200 can be smaller than the effective diameter of at least some of the lenses made of plastic.

[0255] Within the lens unit 200, there can be at least one lens, for example, at least two lenses, each of which is larger than the average effective diameter of the plastic lens. When the average effective diameter of the plastic lens is PLca_Aver and the average effective diameter of the glass lens is GLca_Aver, the condition PLca_Aver < GLca_Aver can be satisfied. In addition, the condition 1 < GLca_Aver / PLca_Aver < 1.5 can be satisfied. In addition, the relationship between the length of the image sensor 300 and the average effective diameter (PLca_Aver) of the plastic lens can satisfy the condition 1 ≤ PLca_Aver / (ImgH*2) < 1.5. In addition, the relationship between the average effective diameter of the glass lens and the length of the image sensor 300 can satisfy the condition 1.1 < GLca_Aver / (ImgH*2) < 1.5. The difference between the maximum length of the image sensor 300 and the effective diameter of the plastic lens may not be large. Therefore, by arranging the plastic lens having a small effective diameter adjacent to the image sensor 300, the plastic lens can disperse the color from the central portion to the edge portion of the image sensor 300.

[0256] The average effective diameter of the glass material can be 10 mm or more, for example, in the range of 10 mm to 15 mm. The average effective diameter of the plastic material can be 8 mm or more, for example, in the range of 8 mm to 12 mm. The lens with the smallest effective diameter can be made of plastic, and the lens with the largest effective diameter can be made of glass. The smallest effective diameter in the lens unit 200 can be in the range of 7 mm to 10 mm, and the largest effective diameter can be in the range of 11 mm to 15 mm. The plastic lens is designed to have a smaller effective diameter than the glass lens, and is set not to contact the lens barrel, thereby minimizing the change in optical performance caused by temperature changes. In addition, the optical system 1500 can improve the resolution and chromatic aberration control characteristics by controlling the incident light, and the vignetting characteristics of the optical system 1500 can be improved.

[0257] The optical system 1500 or the camera module may include an image sensor 300. The image sensor 300 may detect light and convert the light into an electrical signal. The image sensor 300 may detect light that sequentially passes through the lens unit 200. The image sensor (300) may include an element capable of detecting incident light, such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

[0258] Here, the length of the image sensor 300 is the maximum length in the diagonal direction orthogonal to the optical axis OA, and may be smaller than the effective diameter of the lens closest to the object in the first lens group LG1, and larger than the effective diameter of the lens closest to the sensor in the second lens group LG2. Here, the number of lenses having an effective diameter greater than the length of the image sensor 300 may be 4 to 6, and the number of lenses having an effective diameter less than the length of the image sensor 300 may be 1 to 3.

[0259] The optical system 1500 or the camera module may include a filter 500. The filter 500 may be disposed between the second lens group LG2 and the image sensor 300. The filter 500 may be disposed between the image sensor 300 and a lens closest to the sensor among the lenses of the lens unit 200. For example, the filter 500 may be disposed between the nth lens and the image sensor 300.

[0260] The cover glass 400 is disposed between the filter 500 and the image sensor 300, protects the upper portion of the image sensor 192, and prevents the reliability of the image sensor 192 from being deteriorated. The cover glass 400 may be removed. The cover glass 400 may be a protective glass.

[0261] The filter 500 may include an infrared filter or an infrared cut filter (IR cut). The filter 500 may allow light of a set wavelength band to pass through and filter out light of a different wavelength band. When the filter 500 includes an infrared filter, it may prevent radiant heat emitted from external light from being transmitted to the image sensor 300. In addition, the filter 500 may allow visible light to pass through and reflect infrared light.

[0262] The optical system 1500 according to an embodiment may include an aperture (stop). The aperture may adjust the amount of light incident on the optical system 1500. In a lens disposed between an object and an aperture, the effective diameter of the lens surface tends to increase from the object side to the aperture. In a lens surface disposed between the aperture and a sensor, the effective diameter of the lens surface tends to decrease from the aperture to the sensor side. The tendency of the effective diameter of the lens surface to increase or decrease does not only mean a case where the effective diameter of the lens surface increases or decreases. For example, it also includes a case where the effective diameter of the lens surface increases and then decreases as it moves from the aperture to the sensor side.

[0263] The aperture may be set at a set position. For example, the aperture may be set around the object side or sensor side of the lens closest to the object side among the lenses of the second lens group LG2. Different from this, the aperture may be set around the object side surface or sensor side surface of the object side lens of the first lens group LG1. Different from this, at least one lens selected from a plurality of lenses may be used as the aperture. Specifically, the object side surface or sensor side surface of one lens selected from the lenses of the optical system 1500 may be used as the aperture for controlling the amount of light.

[0264] In the optical system 1500 of the embodiment, the sum of the refractive indexes of the lenses of the lens unit 200 may be 8 or more, for example, in the range of 8 to 15, and the average value of the refractive index may be in the range of 1.58 to 1.7. The sum of the Abbe numbers of each of the lenses may be 270 or more, for example, in the range of 280 to 350, and the average value of the Abbe numbers may be 50 or less, for example, in the range of 35 to 47. The sum of the center thicknesses of the entire lens may be 20 mm or more, for example, in the range of 25 mm to 30 mm, and the average value of the center thickness may be in the range of 3.5 mm to 4.0 mm. The sum of the center gaps between the lenses on the optical axis OA may be 3 mm or more, for example, in the range of 4 mm to 6 mm, and may be less than the sum of the center thicknesses of the lenses. In addition, the average value of the effective diameter of each of the lens surfaces S1 to S14 of the lens unit 200 may be set to 8 mm or more, for example, in the range of 8 mm to 15 mm.

[0265] In the optical system according to the second embodiment of the present invention, the viewing angle (diagonal) may be 50 degrees or less, for example, in the range of 20 to 50 degrees. The F number of the optical system or camera module may be 2.4 or less, for example, in the range of 1.4 to 2.4 or 1.5 to 1.8. In the optical system according to the embodiment of the present invention, the maximum viewing angle (diagonal) may be 50 degrees or less, for example, in the range of 20 to 50 degrees. The vehicle optical system may have a horizontal viewing angle (FOV_H) in the Y-axis direction, which is greater than 20 degrees and less than 40 degrees, for example, in the range of 25 to 35 degrees. In addition, the vertical viewing angle is set to an angle less than the horizontal viewing angle, and may be 20 degrees or less, for example, in the range of 10 to 20 degrees. At this time, the sensor length in the horizontal direction (Y) may be 8.064 mm ± 0.5 mm, and the sensor height in the vertical direction (X) may be 4.54 mm ± 0.5 mm. The horizontal field of view (FOV_H) is the field of view relative to the horizontal length of the sensor. Therefore, it is possible to suppress the focus focusing position from changing due to temperature change, and it can be provided as a vehicle imaging device in which various aberrations are well corrected.

[0266] Since the second embodiment is an optical system applied to a vehicle camera device, even if it is designed to use a plastic lens and a glass lens together, the first lens 201 can be set to a glass material. This is because the glass material has the advantages of being scratch-resistant and insensitive to external temperature compared to the plastic material. The first lens 201 can be a glass molded lens having an aspherical surface and made of a glass material. The glass molded lens can be manufactured by placing an optical glass ingot inside a mold having an aspherical shape and through a heating and compression process.

[0267] In order to more effectively prevent scratches caused by foreign matter or objects set inside the vehicle, a glass lens can be used as the first lens 201, and the object side surface of the first lens 201 can have a gently curved shape so as not to contact the external structure. In this way, scratches caused by contact with the external structure can be minimized. In order to perform driver monitoring, front / rear shooting or lane detection of the vehicle while the vehicle is being driven, and detection of objects around the vehicle, the viewing angle can be greater than 20 degrees and less than 40 degrees, and for example can be in the range of between 25 degrees and 35 degrees. The horizontal viewing angle can be a preset angle of an advanced driver assistance system (ADAS).

[0268] The optical system 1500 according to the second embodiment may further include a reflective member 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 lens. Hereinafter, the optical system according to the embodiment will be described in detail.

[0269] An optical system according to a second embodiment of the present invention will be described.

[0270] Fig.15 is a cross-sectional side view of an optical system and an image pickup device module having the optical system according to a second embodiment; Fig.16 It is used to explain the Fig.15 A cross-sectional view showing the relationship between an n-th lens and an n-1-th lens; Fig.17 It is shown Fig.15 A table of lens characteristics of an optical system; Fig.18 It is shown Fig.15 Table of aspheric coefficients of lenses in optical systems; Fig.19 It is shown Fig.15 A table of the thickness of each lens in the optical system and the gaps between adjacent lenses; Fig. 20 It is shown Fig.15 A table of sag values ​​of lens surfaces of the third lens to the sixth lens in the optical system; Fig.21 It shows that according to Fig.15 A table of chief ray angle (CRA) data at room temperature, low temperature, and high temperature for a position of an image sensor in an optical system; Figure 22 to Figure 24 is shown with Fig.15 A graph of data related to the diffraction modulation transfer function (MTF) of an optical system at room temperature, low temperature, and high temperature; Figure 25 to Figure 27 is shown with Fig.15 A graph of data related to aberration characteristics of an optical system at room temperature, low temperature, and high temperature; and Fig.28 is a graph showing relative illuminance according to the height of the image sensor according to the second embodiment.

[0271] Reference Figures 15 to 18 , the optical system 1500 includes a lens unit 200, and the lens unit 200 may include first to seventh lenses 201 to 207. The first to seventh lenses 201 to 207 may be sequentially disposed along an optical axis OA of the optical system 1500. Light corresponding to information about an object may pass through the first to seventh lenses 201 to 207 and the filter 500 to be incident on the image sensor 300.

[0272] The first lens 201 is the lens closest to the object side in the first lens group LG1. The seventh lens 207 is the lens closest to the image sensor 207 in the second lens group LG2 or the lens unit 200. The first lens 201 may be the first lens group LG1, and the second to seventh lenses 202, 203, 204, 205, 206, and 207 may be the second lens group LG2. An aperture may be provided on the periphery of the object side surface or the sensor side surface of the first lens 201 or on the periphery of the object side surface or the sensor side surface of the second lens 202. For example, an aperture (stop) may be provided on the periphery of the object side surface of the second lens 202.

[0273] The first lens 201 may be disposed closest to the object side. The first lens 201 may be disposed farthest from the sensor side. The first lens 201 may have a negative (-) refractive power on the optical axis OA. The first lens 201 may include a plastic material or a glass material, and may be, for example, a glass material. The first lens 201 made of a glass material may reduce changes in the center position and the radius of curvature due to temperature changes according to the surrounding environment, and may protect the incident side surface of the optical system 1500.

[0274] The object-side first surface S1 of the first lens 201 may be convex with respect to the optical axis, and the sensor-side second surface S2 may be concave. The first lens 201 may have a meniscus shape convex toward the object side. The first lens 201 is made of a glass material and may have an aspherical surface. The aspherical coefficients of the first surface S1 and the second surface S2 may be set to Fig.18 L1S1 and L1S2. The first lens 201 may be manufactured as a lens having an aspherical surface by injection molding a glass material. The first lens 201 may be a glass molded lens having an aspherical surface and made of a glass material. The glass molded lens may be manufactured by placing an optical glass ingot in a mold having an aspherical shape through a heating and compression process.

[0275] The effective radius r11 of the first lens 201 may be greater than the effective radius of the plastic lens. Different from this, at least one of the object-side surface and the sensor-side surface of the first lens 201 may have a free surface, that is, a non-rotationally symmetric surface.

[0276] Since the first surface S1 is convex and the second surface S2 is concave, the incident light can be refracted in a direction away from the optical axis OA, and the gap between the first lens 201 and the second lens 202 can be reduced. In addition, the effective diameter of the sensor-side surface of the second lens 202 can be designed to be smaller than the effective diameter of the object-side surface due to the shape of the lens surface of the first lens 201. The first surface S1 of the first lens 201 can be set to have no critical point from the optical axis OA to the end (i.e., edge) of the effective area. The second surface S2 of the first lens 201 can be set to have no critical point.

[0277] The refractive index n1 of the first lens 201 may satisfy the condition of n1>1.8 or n1>1.82. Since the refractive index n1 of the first lens 201 is the largest within the lens unit 200, the radius of curvature of the first lens 201 and the second lens 202 may be increased, and lens manufacturing may be facilitated. If the refractive index n1 of the first lens 201 is less than the condition, the lens surface must be formed to be sharply concave or convex to increase the refractive index of the first lens 201 and the second lens 202, and in this case, lens manufacturing is not easy, the lens defect rate increases, and this may cause a decrease in the yield rate.

[0278] The second lens 202 may be disposed second from the object side. The second lens 202 may be disposed sixth from the sensor side. The second lens 202 may be disposed between the first lens 201 and the third lens 203. The second lens 202 may have a positive (+) refractive power on the optical axis OA. The second lens 202 may include a plastic or glass material. For example, the second lens 202 may be provided as a glass material.

[0279] The object-side third surface S3 of the second lens 202 may be concave with respect to the optical axis OA, and the sensor-side fourth surface S4 may be convex. The second lens 202 may have a meniscus shape convex toward the sensor side. The second lens 202 is made of a glass material and may be a spherical surface. At least one or both of the third surface S3 and the fourth surface S4 may be spherical.

[0280] The aperture (stop) can be set around the sensor-side fourth surface S4 of the second lens 202. The aperture can reduce TTL within the field of view, and the optical system can be miniaturized. Therefore, the yield of the optical system according to weight can be prevented from decreasing, and the production efficiency can be improved. In addition, the optical system can be miniaturized by reducing TTL within a horizontal field of view (FOV_H) of 25 degrees to 36 degrees.

[0281] The third lens 203 may be disposed at the third from the object side. The third lens 203 may be disposed at the fifth from the sensor side. The third lens 203 may be disposed between the second lens 202 and the fourth lens 204. The third lens 203 may have a positive (+) refractive power on the optical axis OA. The third lens 203 may include a plastic or glass material. For example, the third lens 203 may be provided as a glass material.

[0282] The object-side fifth surface S5 of the third lens 203 may be convex relative to the optical axis, and the sensor-side sixth surface S6 may be convex. The third lens 203 may have a shape in which both surfaces are convex relative to the optical axis OA. The third lens 203 is made of a glass material and may be a spherical surface. At least one or all of the fifth surface S5 and the sixth surface S6 may be spherical. At least one or all of the fifth surface S5 and the sixth surface S6 may be set to have no critical point from the optical axis OA to the end of the effective area.

[0283] Since both sides of the third lens 203 are convexly arranged, the TTL and the number of lenses of the optical system can be minimized, and light can be refracted efficiently. In addition, when the radius of curvature of the fifth surface S5 of the third lens 203 is L3R1 and the radius of curvature of the sixth surface (S6) is L3R2, the condition of L3R1>|L3R2| can be satisfied. When this condition is satisfied, light is effectively refracted by the fifth surface S5, so that the effective diameters of the fourth lens 204 to the seventh lens 207 can be guided not to increase, and the TTL can be reduced. If the condition of L3R1<|L3R2| exists, a large amount of aberration may occur on the object side surface of the third lens 203, the refraction efficiency of light may be reduced on the sensor side surface, the effective diameter of the rear lens may increase, and the TTL may also become larger. The absolute value of the radius of curvature on both sides of the third lens 203 may be the same. When the condition of L3R1=|L3R2| is satisfied, since each of the object side surface and the sensor side surface has a convex shape with the same curvature, the same optical characteristics can be obtained regardless of the direction in which one surface or the other surface of the third lens 203 is set, and can be promoted by the lens assembly.

[0284] The fourth lens 204 may be disposed at the fourth from the object side. The fourth lens 204 may be disposed at the fourth from the sensor side. The fourth lens 204 may be disposed between the third lens 203 and the fifth lens 205. The fourth lens 204 may have a positive (+) refractive power or a negative (-) refractive power on the optical axis OA. The fourth lens 204 may have a positive (+) refractive power. The fourth lens 204 may have a positive (+) refractive power different from the positive (+) refractive power of the fifth lens 205. The fourth lens 204 may include a plastic material or a glass material. For example, the fourth lens 204 may be made of a plastic material. The fourth lens 204 may be made of the same material as the fifth lens 205.

[0285] The seventh surface S7 on the object side of the fourth lens 204 may be convex relative to the optical axis, and the eighth surface S8 on the sensor side may be concave. The fourth lens 204 may have a meniscus shape convex toward the object side. The fourth lens 204 is made of a plastic material and may have an aspherical surface. At least one or both of the seventh surface S7 and the eighth surface S8 may be aspherical. The seventh surface S7 and the eighth surface S8 may be arranged to have no critical point from the optical axis OA to the end of the effective area.

[0286] The fifth lens 205 may be disposed at the fifth from the object side. The fifth lens 205 may be disposed at the third from the sensor side. The fifth lens 205 may be disposed between the fourth lens 204 and the sixth lens 206. The fifth lens 205 may have a positive (+) refractive power or a negative (-) refractive power on the optical axis OA. The fifth lens 205 may have a negative (-) refractive power. The fifth lens 205 may have a negative (-) refractive power different from the negative (-) refractive power of the fourth lens 204. The fifth lens 205 may include a plastic material or a glass material. For example, the fifth lens 205 may be made of a plastic material. The fifth lens 205 may be disposed with the same material as the fourth lens 204.

[0287] The ninth surface S9 on the object side of the fifth lens 205 may be convex with respect to the optical axis OA, and the tenth surface S10 on the sensor side may be concave. The fifth lens 205 may have a meniscus shape convex from the optical axis OA toward the object. The fifth lens 205 may be made of a plastic material and may have an aspherical surface. At least one of the ninth surface S9 and the tenth surface S10 may be an aspherical surface. At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 205 may be arranged to have no critical point from the optical axis OA to the end of the effective area.

[0288] The fourth lens 204 and the fifth lens 205 may be bonded. The bonding surface between the fourth lens 204 and the fifth lens 205 may be defined as an eighth surface S8. The eighth surface S7 may be the same surface as the ninth surface of the fifth lens 205. The object side surface of the cemented lens 245 may be convex, and the sensor side surface may be concave. The gap between the fourth lens 204 and the fifth lens 205 may be less than 0.01 mm, and may be bonded with an adhesive. From the optical axis OA to the end of the effective area, the gap between the fourth lens 204 and the fifth lens 205 may be less than 0.01 mm. The fourth lens 204 and the fifth lens 205 may have opposite refractive powers. The refractive power of the combination of the fourth lens 204 and the fifth lens 205 may have a positive (+) refractive power.

[0289] The value of the curvature radius of the bonding surface S8 of the bonding lens 245 may be greater than 30. For example, the value of the curvature radius of the bonding surface S8 of the bonding lens 245 may be greater than 50. The bonding surface S8 of the bonding lens 245 may be formed into a gentle shape. In this way, the bonding process of the fourth lens 204 and the fifth lens 205 forming the bonding lens 245 is favorable, and the bonding retention force can be improved.

[0290] The product of the refractive power of the object-side fourth lens 204 of the cemented lens 245 and the refractive power of the sensor-side fifth lens 205 may be less than 0. The product of the focal length of the object-side fourth lens 205 of the cemented lens 245 and the focal length of the sensor-side fifth lens 205 may be less than 0. Therefore, the aberration characteristics of the optical system can be improved. If the refractive powers of the two lenses of the cemented lens 245 are the same, there is a limit to the improvement of the aberration.

[0291] The combined refractive power of the cemented lens 245 has a positive refractive power, and the fourth lens 204 on the object side and the fifth lens 205 on the sensor side relative to the cemented lens 245 may have a positive refractive power. Therefore, the fourth lens 204, the cemented lens 245, and the fifth lens 205 may refract some of the incident light in the direction of the optical axis, and chromatic aberration may be corrected mutually. The focal length of the fourth lens 204 disposed on the object side relative to the cemented lens 245 may be smaller than the focal length of the fifth lens 205 disposed on the sensor side. The power of the fourth lens 204 disposed on the object side relative to the cemented lens 245 may be greater than the power of the fifth lens 205 disposed on the sensor side.

[0292] The effective diameter of the fourth lens 204 may be greater than the diagonal length of the image sensor 300. The effective diameter of the fourth lens 204 is the average of the effective diameters of the seventh surface S7 and the eighth surface S8, and may be greater than the diagonal length of the image sensor 300. The effective diameter of the fifth lens 205 may be less than the effective diameter of the fourth lens 204 and greater than the diagonal length of the image sensor 300.

[0293] When the effective diameter of the seventh surface S7 of the fourth lens 204 is CA_L4S1 and the effective diameter of the eighth surface S8 is CA_L4S2, the effective diameters of the seventh surface S7 and the eighth surface S8 may satisfy the condition 1 < CA_L4S1 / CA_L4S2 < 1.5. When the effective diameter of the ninth surface S9 of the fifth lens 205 is CA_L5S1 and the effective diameter of the tenth surface S10 is CA_L5S2, the effective diameters of the ninth surface and the tenth surface may satisfy the condition 1 < CA_L5S1 / CA_L5S2 < 1.5.

[0294] The cemented lens 245 may be joined with plastic lenses having different refractive indices. The object side and the sensor side of the cemented lens 245 may have aspherical surfaces, and the joining surface may have a spherical surface. By increasing the plastic material lenses included in the optical system, the weight of the optical system can be reduced, and the plastic material is easy to polish and process, resistant to external shocks, has high price competitiveness, and can be easily obtained. In addition, various aberrations can be corrected by the plastic lenses, so that deterioration of optical performance can be prevented. If the lens that is not the cemented lens 245 on the sensor side is an aspherical lens or a plastic lens, spherical aberration can be compensated. In addition, since the lens that is not the cemented lens 245 on the sensor side is a plastic lens and is set as a lens with a small effective diameter, the light traveling through the plastic lens toward the image sensor 300 can be effectively guided. Since the position of the cemented lens 245 is within any two consecutive lenses among the third lens to the sixth lens located in the middle or after the middle in the lens unit 200, chromatic aberration correction can be more efficient.

[0295] The sixth lens 206 may be arranged as the sixth from the object side. The sixth lens 206 may be arranged as the second from the sensor side. The sixth lens 206 may be arranged between the fifth lens 205 and the seventh lens 207. The sixth lens 206 may have a positive (+) refractive power or a negative (-) refractive power on the optical axis OA. The sixth lens 206 may have a positive (+) refractive power. The sixth lens 206 may include a plastic material or a glass material. For example, the sixth lens 206 may be made of a plastic material.

[0296] The eleventh surface S11 on the object side of the sixth lens 206 may be convex with respect to the optical axis OA, and the twelfth surface S12 on the sensor side may be concave. The sixth lens 206 may have a meniscus shape that is convex from the optical axis OA to the object side. Different from this, the sixth lens 206 may have a shape that is convex on both sides. At least one or both of the eleventh surface S11 and the twelfth surface S12 may be aspherical. The aspherical coefficients of the eleventh surface S11 and the twelfth surface S12 may be set to Fig.18 L6, L1 and L2.

[0297] The eleventh surface S11 of the sixth lens 206 may be disposed to have no critical point from the optical axis OA to the end of the effective area. The twelfth surface S12 may be disposed to have no at least one critical point from the optical axis OA to the end of the effective area.

[0298] The seventh lens 207 may be disposed closest to the sensor side. The seventh lens 207 may be disposed farthest from the object side. The seventh lens 207 may have a positive (+) refractive power or a negative (-) refractive power on the optical axis OA. The seventh lens 207 may have a negative (-) refractive power. The seventh lens 207 may include a plastic or glass material. For example, the seventh lens 207 may be made of a plastic material.

[0299] The object-side 13th surface S13 of the seventh lens 207 on the optical axis may be convex, and the sensor-side 14th surface S14 may be concave. The seventh lens 207 may have a meniscus shape convex toward the object side. At least one of the 13th surface S13 and the 14th surface S14 may be aspherical. For example, both the 13th surface S13 and the 14th surface S14 may be aspherical. The aspherical coefficients of the 13th surface S13 and the 14th surface S14 may be set to Fig.18 S1 and S2 of L7.

[0300] The thirteenth surface S13 of the seventh lens 207 may have a critical point from the optical axis OA to the end of the effective area. When the thirteenth surface S13 has a critical point, it may be located at 50% or more of the effective radius (r71) from the optical axis OA, or in the range of 52% to 70%, or in the range of 53% to 60%. When the fourteenth surface S14 has a critical point, it may be located at 70% or more of the effective radius (r72) from the optical axis OA, or in the range of 70% to 90%, or in the range of 75% to 85%.

[0301] The seventh lens 207 may be a plastic lens that is closest to the image sensor 300. In addition, by arranging two or more plastic lenses adjacent to the image sensor 300, aberrations such as spherical aberration and chromatic aberration may be improved by a lens surface having an aspherical surface, and the influence on the resolution may be controlled. In addition, by arranging the plastic lens as a lens adjacent to the image sensor 300, the plastic lens may be insensitive to assembly tolerances compared to a glass lens. That is, insensitivity to assembly tolerances means that even if the assembly is slightly different from the design during assembly, the optical performance will not be significantly affected. In addition, by setting the two lenses 206 and 207 adjacent to the image sensor 300 to plastic, the optical performance may be improved by a lens surface having an aspherical surface, and, for example, aberration characteristics may be improved and resolution degradation may be prevented.

[0302] The sixth lens 206 and the seventh lens 207 are arranged to be spaced apart from each other, but may include characteristics of a cemented lens. The sixth lens 206 and the seventh lens 207 may have opposite refractive powers. The product of the refractive power of the sixth lens 206 and the refractive power of the seventh lens 207 may be less than zero. The product of the focal length of the sixth lens 206 and the focal length of the seventh lens 207 may be less than zero. Therefore, the aberration characteristics of the optical system may be improved. If the refractive powers of the two lenses having the characteristics of a cemented lens are the same, there is a limit to the improvement of the aberration.

[0303] The sixth lens 206 and the seventh lens 207 may be formed of the same material. The sixth lens 206 and the seventh lens 207 may be formed of a plastic material. The sixth lens 206 and the seventh lens 207 may be formed of the same material as the cemented lens 245.

[0304] At least one or both of the 13th surface S13 and the 14th surface S14 of the seventh lens 207 may have a critical point. The 13th surface S13 of the seventh lens 207 may have a first critical point P1 from the optical axis OA to the end of the effective area. The first critical point P1 of the 13th surface S13 may be located at 55% or more of the effective radius from the optical axis OA, or in the range of 55% to 75%, or in the range of 60% to 70%. The first critical point of the 13th surface S13 may be located at a distance of 2 mm or more from the optical axis OA, for example, in the range of 2.1 mm to 2.5 mm, or in the range of 2.2 mm to 2.3 mm. As another example, the 13th surface S13 may be set to have no critical point. The 13th surface S13 having the first critical point P1 may refract incident light to the central portion and the edge portion, and improve aberrations. The first critical point P1 and the second critical point P2 are points where the sign of the gradient value relative to the optical axis OA and the direction perpendicular to the optical axis OA changes from positive (+) to negative (-) or from negative (-) to positive (+), and may refer to a point where the gradient value is 0. In addition, the first critical point P1 and the second critical point P2 may be points where the gradient value of a tangent line passing through the lens surface increases and then decreases, or may be points where the gradient value decreases and then increases.

[0305] The fourteenth surface S14 of the seventh lens 207 may have at least one second critical point P2 from the optical axis OA to the end of the effective area. The second critical point P2 of the fourteenth surface S14 may be located at a distance of 60% or more of the effective radius (r72) from the optical axis OA, or in a range of 60% to 80%, or in a range of 65% to 75%. The second critical point P2 of the fourteenth surface S14 may be located at a distance of 2.9 mm or more from the optical axis OA, for example, in a range of 2.9 mm to 3.9 mm, or in a range of 3.1 mm to 3.7 mm. Therefore, the second critical point P2 is disposed closer to the edge than the first critical point P1, so that the seventh lens 207 can refract the incident light to the edge portion of the image sensor 300.

[0306] The average effective radius of the 13th surface S13 and the 14th surface S14 of the 7th lens 207 is set to be less than ImgH, which is half the diagonal length of the image sensor 300, and this can refract light to the edge portion of the image sensor 300 through the 14th surface S14 having the second critical point P2.

[0307] like Fig.15 and Fig.16As shown, the center thickness of the first lens 201 to the seventh lens 207 is represented by CT1 to CT7, the edge thickness at the end of the effective area of ​​each lens is represented by ET1 to ET7, the center gap between two adjacent lenses is represented by CG1 to CG6, and the edge gap between the edges of each lens is represented by EG1 to EG6. Here, the center thickness of the cemented lens 245 is CT45, and the edge thickness is represented by ET45.

[0308] Reference Fig.16 , the back focal length (BFL) is the optical axis distance from the image sensor 300 to the center of the last lens. Fig.15 , TTL is an optical axis distance from the center of the first surface S1 of the first lens 201 to the upper surface of the image sensor 300 .

[0309] Fig.17 yes Fig.15 An example of lens data of the optical system of the second embodiment. Fig.17 As shown, the radius of curvature at the optical axis OA of the first to seventh lenses 201, 202, 203, 204, 205, 206 and 207, the thickness of the lenses, the distance between the lenses, the refractive index at the d-line, the Abbe number and the size of the clear aperture (CA) can be set.

[0310] like Fig.18 As shown, in the lenses of the lens unit 200 of the second embodiment, the lens surfaces of the first lens 201, the fourth lens 204, the fifth lens 205, the sixth lens 206, and the seventh lens 207 may include an aspheric surface having a 30th order aspheric surface coefficient. For example, the first lens 201, the fourth lens 204, the fifth lens 205, the sixth lens 206, and the seventh lens 207 may include a lens surface having a 30th order aspheric surface coefficient. As described above, since the aspheric surface having the 30th order aspheric surface coefficient (a numerical value other than "0") can significantly change the aspheric shape of the edge portion, the optical performance of the edge portion of the field of view (FOV) can be well corrected.

[0311] like Fig.19 As shown, the thicknesses (T1 to T7) of the first to seventh lenses 201, 202, 203, 204, 205, 206, and 207 and the gaps (G1 to G6) between two adjacent lenses may be set. Fig.19 As shown, the thickness (T1 to T7) of each lens in the Y-axis direction can be expressed at intervals of 0.1 mm or 0.2 mm or more, and the gap (G1 to G6) between each lens can be expressed at intervals of 0.1 mm or 0.2 mm or more.

[0312] Reference Fig.17 and Fig.19 , when comparing the absolute value of the radius of curvature of each lens, the radius of curvature of the twelfth surface S12 of the sixth lens 206 on the optical axis (OA) may be the largest among the lenses, and the radius of curvature of the tenth surface S10 of the fifth lens 205 may be the smallest among the lenses. The difference between the maximum radius of curvature and the minimum radius of curvature may be 10 times or more, for example, 10 times to 15 times.

[0313] When the center thickness of the lens is described with respect to the optical axis, the center thickness (CT2) of the second lens 202 is the largest among the lenses, and the center thickness (CT5) of the fifth lens 205 is the smallest among the lenses. The difference between the maximum center thickness and the minimum center thickness among the lenses may be in the range of 1.5 mm or more and 2.5 mm or less.

[0314] When explaining the center gap (CG) between the lenses, the center gap (CG1) between the first lens 201 and the second lens 202 may be the largest, and the center gap (CG3) between the third lens 203 and the fourth lens 204 may be the smallest. Here, the minimum center gap does not include the bonding surface of the cemented lens 245. The difference between the maximum center gap and the minimum center gap in the spaced lens gaps may be 1.2 mm or more, for example, in the range of 1.3 mm to 1.8 mm. In addition, by setting the maximum center gap between the lenses to 70% or less of the maximum center thickness, for example, in the range of 30% to 70%, the thickness of the camera module to which a plastic lens having a thin thickness is applied may not be increased without increasing the center gap compared to the center thickness of each lens.

[0315] When explaining about the effective diameter, the lens with the largest effective diameter may be disposed between the first lens 201 closest to the object and the seventh lens 207 closest to the image sensor 300. The lens with the largest effective diameter may be a glass lens. The lens with the largest effective diameter may be disposed between the first lens 201 and the cemented lens 245. The lens with the largest effective diameter may be the third lens 203. Here, the effective diameter is the average value of the effective diameters of the object side surface and the sensor side surface of each lens. The lens surface with the largest effective diameter may be the sixth surface S6 of the third lens 203 or the object side surface of the cemented lens 245.

[0316] The lens with the smallest effective diameter may be any one of the plastic lenses, such as the seventh lens 207 adjacent to the image sensor 300. For example, the effective diameter of the seventh lens 207 may be the smallest value within the lens unit 200. The lens surface with the smallest effective diameter may be the thirteenth surface S13 of the seventh lens 207.

[0317] The effective diameter of each of the first to fourth lenses 201 to 204 adjacent to the object side may be greater than the effective diameters of the fifth, sixth, and seventh lenses 205, 206, and 207 adjacent to the sensor side. The effective diameters of the first to fourth lenses 201 to 204 may be greater than the diagonal length of the image sensor 300. The average effective diameter of the seventh lens 207 may be smaller than the diagonal length of the image sensor 300. Therefore, light incident through a plurality of lenses aligned along the optical axis may be guided to the image sensor 300.

[0318] When explaining the refractive index, the refractive index of the first lens 201 can be the largest among the lenses and can be greater than 1.8, for example, greater than 1.82. Any one or both of the second lens 202 and the sixth lens 206 can have the smallest refractive index among the lenses. For example, the minimum refractive index can be less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index can be 0.2 or greater. By providing a high refractive index lens made of glass closest to the object and providing a lens adjacent to the glass lens and a lens adjacent to the image sensor 300 as a low refractive index lens made of plastic, the incident efficiency can be improved, and the refractive power between the glass lens and the plastic lens can be adjusted to guide the image sensor 300.

[0319] When comparing the Abbe numbers, the Abbe number of the third lens 203 is the largest among the lenses and may be 60 or more. The Abbe numbers of the fifth lens 205 and the seventh lens 207 are the smallest among the lenses and may be 25 or less. The difference between the maximum refractive index and the minimum Abbe number may be 40 or more. By maximizing the Abbe number of the third lens 203 adjacent to the cemented lens 245 and minimizing the Abbe number of the seventh lens 207 having a low refractive index adjacent to the image sensor 300, dispersion of light traveling between lenses made of glass can be controlled, and dispersion between lenses made of glass and plastic can be increased to guide light to the image sensor 300.

[0320] The focal lengths (F1, F5, and F7) of the first lens 201, the fifth lens 205, and the seventh lens 207 may have a negative (-) sign. The first lens 201, the fifth lens 205, and the seventh lens 207 may have a negative (-) refractive power. The focal lengths (F3, F4, F5, and F6) of the third lens 203, the fourth lens 204, the fifth lens 205, and the sixth lens 206 may have a positive (+) sign. The third lens 203, the fourth lens 204, the fifth lens 205, and the sixth lens 206 may have a positive (+) refractive power. The second lens 202, the third lens 203, and the fourth lens 204 having a positive (+) refractive power may be disposed on the sensor side of the first lens 201 having a negative (-) refractive power. In this way, light incident on the object side may move away from the optical axis direction and then be gathered again in the optical axis direction, thereby forming a stable light path.

[0321] In addition, the sixth lens 206 and the seventh lens 207 which are adjacently disposed lenses may satisfy the following conditions.

[0322] Condition 1: The refractive index of the lens with positive refractive power < the refractive index of the lens with negative refractive power

[0323] Condition 2: Dispersion value of lens with positive refractive power > dispersion value of lens with negative refractive power

[0324] Here, in the plastic lens, the sixth lens 206 has a positive refractive power, and the seventh lens 207 has a negative refractive power, so that according to conditions 1 and 2, the refractive index of the sixth lens is smaller than the refractive index of the seventh lens, and the dispersion value of the sixth lens is larger than the dispersion value of the seventh lens. Chromatic aberration occurring in the plastic lens can be corrected by the plastic lens. In addition, since the sixth lens 206 and the seventh lens 207, which are plastic lenses disposed continuously, satisfy a refractive index difference of 0.1 or more and 0.15 or less and an Abbe number difference of 20 or more and 60 or less, chromatic aberration occurring in the plastic lens can be compensated by the plastic lens.

[0325] The optical system has chromatic aberration, and chromatic aberration is corrected by using a cemented lens or two lenses arranged in series. When the temperature changes from low to high, the lens repeatedly contracts and expands. Since the lens characteristics of lenses of the same material change by the same amount according to temperature changes, it is effective to correct chromatic aberration between lenses of the same material even when the temperature changes.

[0326] Therefore, in the second embodiment of the present invention, chromatic aberration occurring in the plastic lens is corrected by using the cemented lens 245 , the sixth lens 206 , and the seventh lens 207 .

[0327] When the fourth lens 204 and the fifth lens 205 as a cemented lens satisfy a refractive index difference of 0.1 or more and 0.15 or less and an Abbe number difference of 20 or more and 60 or less, chromatic aberration occurring in the plastic lens can be compensated by the plastic lens. The refractive index difference is rounded to the third decimal place, and the Abbe number difference is rounded to the first decimal place to compare these values.

[0328] When the focal lengths are compared in absolute values, the focal length of the second lens 202 is the largest among the lenses and may be 55 or more or 200 or more. Among the lenses, the second lens 202 made of glass may have the largest focal length and the smallest refractive power. Among the lenses, the lens having the second largest focal length after the second lens 202 may be the sixth lens 206 made of plastic. The focal length of the fifth lens 205 is the smallest among the lenses, and the absolute value of the focal length of the fifth lens 205 may be 15 or less or 10 or less. Among the lenses, the fifth lens 205 made of plastic may have the smallest focal length and the largest refractive power. Since a lens made of plastic having a small refractive power is disposed on the sensor side of the fifth lens 205, the refractive power of the fifth lens 205 may be increased.

[0329] Among the lenses other than the cemented lens 245, the lens having the minimum focal length may be the third lens 203. The difference between the maximum focal length and the minimum focal length may be 50 or more, or 80 or more. Therefore, the optical system may have enhanced MTF characteristics, aberration control characteristics, resolution characteristics, etc. within a set viewing angle range, and may have good optical performance in the edge portion of the viewing angle.

[0330] There is a critical point on the sensor side of the seventh lens 207. The critical point is a point where the trend of the sag value changes. That is, a point where the sag value increases and then decreases, or a point where the sag value decreases and then increases. Fig. 20 , it can be seen that a critical point exists between a point 1.8 mm apart and a point 2.2 mm apart in a direction perpendicular to the optical axis on the object side surface of the seventh lens 207. The sag value on the object side of the seventh lens 207 increases to a point 2.0 mm apart in a direction perpendicular to the optical axis, and then decreases from a point 2.0 mm apart to a point 4.1 mm apart in a direction perpendicular to the optical axis.

[0331] It can be seen that the sensor-side surface of the seventh lens 207 has a critical point between a point 2.8 mm apart and a point 3.2 mm apart in a direction perpendicular to the optical axis. The sensor-side surface of the seventh lens 207 has a sag value that increases to a point 2.9 mm apart in a direction perpendicular to the optical axis and then decreases from a point 2.9 mm apart to a point 4.6 mm apart in a direction perpendicular to the optical axis. If a critical point exists on the sensor-side surface of the seventh lens 207, that is, on the sensor-side surface of the last lens, that is, on the lens surface closest to the sensor, TTL can be reduced, thereby promoting miniaturization and weight reduction of the optical system.

[0332] The first lens 201 may have a thickness (T1) whose maximum thickness is 1 or more times (e.g., 1 to 1.2 times) the minimum thickness, and the center thickness (CT1) is the minimum value, and the edge thickness (ET1) may be the maximum value. The second lens 202 may have a thickness (T2) whose maximum thickness is 1 to 1.2 times the minimum thickness. The center thickness (CT2) of the second lens 202 may be the maximum value, and the edge thickness (ET2) is the minimum value. The thickness (T3) of the third lens 203 may be the maximum at the center and the minimum at the edge, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T4) of the fourth lens 204 may be the maximum at the center and the minimum at the edge, and the maximum thickness is in the range of 1.6 to 2.2 times the minimum thickness. The thickness (T5) of the fifth lens 205 may be the minimum at the center and the maximum at the edge, and the maximum thickness is in the range of 1.2 to 1.5 times the minimum thickness. The thickness (T6) of the sixth lens 206 may be maximum at the center and minimum at the edge, and the maximum thickness may be in the range of 1 to 1.2 times the minimum thickness. The thickness (T7) of the seventh lens 207 may be minimum at the center and maximum at the edge, and the maximum thickness may be in the range of 1 to 1.2 times the minimum thickness.

[0333] The center thickness (CT45) of the cemented lens 245 may be greater than the edge thickness (ET45). The center thickness (CT45) of the cemented lens 245 is the distance from the center of the object-side seventh surface S7 of the fourth lens 204 to the center of the tenth surface S10 of the fifth lens 205, and the edge thickness (ET45) is the distance from the end of the effective area of ​​the seventh surface S7 to the tenth surface S10 in the optical axis direction. The maximum thickness of the cemented lens 245 is the center portion, the minimum thickness is the edge portion, and the maximum thickness may be in the range of 1 to 1.2 times the minimum thickness.

[0334] Among the gaps G1 to G6 between the lenses, the first gap G1 between the first lens 201 and the second lens 202 may have a largest center portion and a smallest edge portion. The second gap G2 between the second lens 202 and the third lens 203 may have a largest edge portion and a smallest center portion. The third gap G3 between the third lens 203 and the fourth lens 204 may have a largest edge portion and a smallest center portion. The fifth gap G5 between the fifth lens 205 and the sixth lens 206 may have a largest center portion and a smallest edge portion. The sixth gap G6 between the sixth lens 206 and the seventh lens 207 may have a largest center portion and a smallest edge portion.

[0335] like Fig.21 As shown, in Fig.15 In the optical system and the camera module, the chief ray angle (CRA) may be 10 degrees or more at 1 field which is the end of the diagonal length of the image sensor, for example, in the range of 10 to 35 degrees or 10 to 25 degrees. In addition, the difference in the chief ray angle from a low temperature (-40 degrees) to a high temperature (95 degrees) may be 1 degree or less. Therefore, even if the temperature changes from a low temperature to a high temperature, the difference in the chief ray angle is not large, and stable optical performance can be achieved.

[0336] like Fig.28 As shown, a graph showing relative illumination according to image height in an optical system according to an embodiment shows that the relative illumination is 70% or more, for example, 75% or more, from the center to the diagonal end of the image sensor. That is, it can be seen that there is almost no difference in relative illumination (zoom positions 1, 2, and 3) according to room temperature, low temperature, and high temperature until 4.5 mm from the optical axis.

[0337] Figure 22 to Figure 24 It is shown Fig.15 Graphs of diffraction modulation transfer functions (MTFs) at room temperature, low temperature, and high temperature in an optical system of FIG. 1 and FIG. 2 are graphs showing modulation according to spatial frequency. Figure 22 to Figure 24 As shown, in the second embodiment of the present invention, the deviation of the MTF at low or high temperature relative to room temperature may be less than 10%, ie, 7% or less.

[0338] Figure 25 to Figure 27 It is shown Fig.15 Graphs of aberration characteristics of an optical system at room temperature, low temperature, and high temperature. Figure 25 to Figure 27 The aberration curves are the measured spherical aberration (longitudinal spherical aberration), astigmatism field curve and distortion from left to right. Figure 25 to Figure 27In , the X-axis may represent the focal length (mm) and the degree of distortion (%), and the Y-axis may represent the height of the image. In addition, the graph of spherical aberration is a graph of light in the wavelength bands of about 435nm, about 486nm, about 546nm, about 587nm, and about 656nm, and the graph of astigmatism and distortion is a graph of light in the wavelength band of about 546nm. Figure 25 to Figure 27 In the aberration diagram, it can be interpreted that the closer each curve at room temperature, low temperature, and high temperature is to the Y-axis, the better the aberration correction function is. It can be seen that the optical system 1500 according to the embodiment has a measurement value close to the Y-axis in almost all areas. That is, the optical system 1500 according to the second embodiment has improved resolution not only in the central part of the field of view (FOV) but also in the edge part and can have good optical performance. Here, the low temperature is -20 degrees or lower, for example, in the range of -20 degrees to -40 degrees, the room temperature is in the range of 22 degrees ±5 degrees, or in the range of 18 degrees to 27 degrees, and the high temperature can be in the range of 85 degrees or higher, for example, in the range of 85 degrees to 105 degrees. Therefore, it can be seen that Figure 25 to Figure 27 The decrease in brightness ratio (modulation) from low temperature to high temperature is less than 10%, for example 5% or less, or hardly changes.

[0339] Table 3 compares the changes in optical properties such as EFL, BFL, F number (F#), TTL and field of view (FOV) at room temperature, low temperature and high temperature in the optical system according to the second embodiment of the present invention, and it can be seen that the rate of change of the optical properties at low temperature is 5% or less, for example, 3% or less relative to room temperature, and it can be seen that the rate of change of the optical properties at low temperature is 5% or less, for example, 3% or less relative to room temperature.

[0340] [Table 3]

[0341] Room temperature Low temperature high temperature Low temperature / room temperature High temperature / room temperature EFL(F) 15.1 15.0382 15.1752 99.59％ 200.49％ BFL 2.5 2.4971 2.50346 99.88％ 200.13％ F# 1.600 1.5934 1.60808 99.58％ 200.50％ TTL 33.965 33.8963 34.0458 99.79％ 200.23％ FOV 33.9838 34.1084 33.8365 200.36％ 99.56％

[0342] Therefore, as shown in Table 3, it can be seen that the change in optical characteristics (e.g., the rate of change of effective focal length (EFL), TTL, BFL, F number, and field of view (FOV)) according to the temperature change from low temperature to high temperature is 10% or less, that is, 5% or less, for example, in the range of 0 to 5%. This makes it possible to design temperature compensation for plastic lenses even when at least one or two or more plastic lenses are used, thereby preventing the reliability of optical characteristics from being reduced.

[0343] The optical system of the second embodiment disclosed above can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only in the central portion but also in the peripheral portion of the field of view (FOV).

[0344] Table 4 shows the terms in the above mathematical formula in the optical system 1500 of the second embodiment, including the total track length (TTL) (mm), the back focal length (BFL), the effective focal length (F) (mm), ImgH (mm), the effective diameter (CA) (mm), the thickness (mm), TTL (mm), the optical axis distance TD from the first surface S1 to the fourteenth surface S14 (mm), the focal length of each lens of the first lens to the seventh lens (F1, F2, F3, F4, F5, F6 and F7) (mm), the sum of the refractive index, the sum of the Abbe number, the sum of the thickness (mm), the sum of the gaps between adjacent lenses, the effective diameter characteristics, the sum of the refractive index of the glass lenses, the sum of the refractive index of the plastic material, the viewing angle (FOV) (degrees), the edge thickness (ET), the focal length of the first lens group and the second lens group, the F number, etc.

[0345] [Table 4]

[0346]

[0347]

[0348] The optical systems 1000 and 1500 according to the first and second embodiments disclosed above may satisfy at least one or two or more of the mathematical expressions described below. Therefore, the optical systems 1000 and 1500 according to the embodiments may have improved optical properties. For example, when the optical systems 1000 and 1500 satisfy at least one mathematical expression, the optical systems 1000 and 1500 may effectively control aberration characteristics such as chromatic aberration and distortion aberration, and may have good optical performance not only in the central part of the field of view (FOV) but also in the edge part. In addition, the optical systems 1000 and 1500 may have improved resolution. In addition, the thickness of the lens on the optical axis OA and the gap between adjacent lenses on the optical axis OA described in the mathematical expression s may refer to the embodiments disclosed above.

[0349] [Mathematical expression 1]

[0350] 0.5 <CT1 / ET1<1

[0351] In Mathematical Expression 1, CT1 is the center thickness of the first lenses 101 and 201, and ET1 is the edge thickness of the first lenses 101 and 201. By doing so, a factor affecting the viewing angle of the optical system can be set, and a factor affecting the effective focal length (EFL) can be set. Mathematical Expression 1 may preferably satisfy 0.6≤CT1 / ET1<1 in the first and second embodiments.

[0352] [Mathematical expression 2]

[0353] 0.1 < CT1 / CA_L1S1 < 0.5

[0354] In Mathematical Expression 2, CT1 is the central thickness of the first lenses 101 and 201, and CA_L1S1 is the effective diameter (CA_L1S1) of the object-side surface (S1) of the first lenses 101 and 201. When Mathematical Expression 2 is satisfied, deterioration of the strength and optical properties of an injection-molded lens made of glass can be prevented. If it is below the range of Mathematical Expression 2, the lens may break or injection molding may be difficult, and if it is greater than the range, the TTL may increase and the weight of the optical system may become heavier. In the first embodiment, Mathematical Expression 2 may preferably satisfy 0.15 < CT1 / CA_L1S1 < 0.25. In the second embodiment, Mathematical Expression 2 may preferably satisfy 0.2 < CT1 / CA_L1S1 < 0.4.

[0355] [Mathematical Expression 3]

[0356] Po1 < 0

[0357] In Mathematical Expression 3, Po1 represents the sign of the refractive power of the first lenses 101 and 201. For the performance of the optical system, compared with the TTL in the optical system, it can be set to have a short effective focal length. If Mathematical Expression 3 is satisfied, the light incident on the first lenses 101 and 201 on the object side can be diffused in a direction away from the optical axis. The entire optical system can have a stable structure that diffuses and then converges light.

[0358] [Mathematical Expression 3-1]

[0359] F6 * F7 < 0

[0360] In Mathematical Expression 3-1, F6 represents the focal length of the sixth lenses 106 and 206, and F7 represents the focal length of the seventh lenses 107 and 207. By the condition of Mathematical Expression 3-1, the product of the focal lengths of the plastic lenses can be set by mixing negative (-) and positive (+) refractive powers so that they can compensate each other.

[0361] [Mathematical Expression 4]

[0362] 1.7 < n1 < 2.2

[0363] In Mathematical Expression 4, n1 is the refractive index of the d-line of the first lenses 101 and 201. Mathematical Expression 4 sets the refractive index of the first lens to be high so that it can control the factor that affects the reduction of the third-order aberration (Seidel aberration) of the optical system, and can reduce the aberration that may occur when the TTL becomes slightly longer. In the first and second embodiments, Mathematical Expression 4 preferably satisfies 1.75 < n1 < 2.1. If it is designed to be lower than the lower limit of Mathematical Expression 4, the aberration may not be effectively reduced, and the refractive power of the first lens may be weakened, making it impossible to effectively collect light, which may deteriorate the performance of the optical system. If it is designed to be higher than the upper limit of Mathematical Expression 4, there is a disadvantage that it becomes difficult to obtain materials. In addition, if the refractive index of the first lenses 101 and 201 is designed to be lower than the lower limit of Mathematical Expression 4, the curvature radii of the first lenses 101, 201 and the second lenses 102 and 202 must be increased to increase the refractive power of the first lenses 101, 201 and the second lenses 102 and 202. In this case, lens manufacturing becomes more difficult, the defect rate of the lenses increases, and the yield may decrease.

[0364] [Mathematical Expression 4-1]

[0365] 1.6 ≤ Aver(n1:n7) ≤ 1.7

[0366] In Mathematical Expression 4-1, Aver(n1:n7) is the average value of the refractive index values at the d-line of the first lens to the seventh lenses 101 to 107, 201 to 207. When the optical systems 1000 and 1500 according to the embodiments satisfy Mathematical Expression 4-1, the optical systems 1000 and 1500 can set the resolution and suppress the influence on the TTL.

[0367] [Mathematical Expression 5]

[0368] 27 < FOV_H < 33

[0369] In Mathematical Expression 5, FOV_H represents the horizontal viewing angle and can set the range of the vehicle optical system. In the first and second embodiments, Mathematical Expression 5 preferably satisfies the range of 28 ≤ FOV_H ≤ 31 or 29.9 degrees ± 3 degrees, and at this time the sensor length in the horizontal direction is based on 8.064 mm ± 0.5 mm. In addition, when Mathematical Expression 5 is satisfied, when the temperature changes from room temperature to high temperature, the change rate of the effective focal length and the change rate of the viewing angle can be set to 5% or less, for example, 0 to 5%. In addition, even if two or more (for example, three or more) plastic lenses are mixed and used in the optical systems 1000 and 1500, the deterioration of the optical characteristics can be prevented by temperature compensation of the plastic lenses.

[0370] [Mathematical expression 6]

[0371] (First embodiment) L3R1>0, L3R2<0

[0372] (Second embodiment) L3R1>0, L3R2<0, |L3R1|=|L3R2|

[0373] In Mathematical Expression 6, L3R1 is the curvature radius of the object side surface of the third lenses 103 and 203, and L3R2 is the curvature radius of the sensor side surface of the third lenses 103 and 203. The third lenses 103 and 203 may have a convex shape on both sides. Since the third lenses 103 and 203 have a convex shape on both sides, light can be refracted so that the effective diameters of the fourth to seventh lenses 104, 204, 105, 205, 106, 206, 107, and 207 disposed on the sensor side surface of the third lenses 103 and 203 do not increase, and the number of lenses can be reduced. In the second embodiment, since the condition of |L3R1|=|L3R2| is satisfied, each of the object side surface and the sensor side surface has a convex shape with the same curvature, so that the same optical characteristics can be obtained regardless of the direction in which one side or the other side of the third lens 103 is disposed, and this can facilitate lens assembly.

[0374] [Mathematical expression 7]

[0375] 1 < L7S2_max_sag < 3 to sensor

[0376] In Mathematical Expression 7, L7S2_max_sag to sensor refers to the straight-line distance from the maximum sag value of the seventh lenses 107 and 207 to the image sensor 300. If this is satisfied, TTL can be reduced, and conditions for manufacturing a camera module can be set. In addition, L7S2_max_sag to sensor can set a space in which the filter 500 and the cover glass 400 located between the image sensor 300 and the seventh lenses 107 and 207 can be set. If the range of Mathematical Expression 7 is less than the lower limit, the space for placing circuit structures such as filters and image sensors becomes more limited, and the process of assembling circuit structures such as filters and image sensors into an optical system may become difficult. If the range of Mathematical Expression 7 is greater than the upper limit, the process of assembling circuit structures such as filters and image sensors into an optical system is easy, but TTL becomes longer, making it difficult to miniaturize the optical system.

[0377] That is to say, the mathematical expression 7 can set the minimum distance between the image sensor 300 and the last lens, and preferably satisfies 1 < L7S2_max_sag to the sensor ≤ BFL. In addition, if there is no point P2 where the last lens protrudes more towards the image sensor compared to the center on the sensor side, the value of the mathematical expression 7 can be equal to the back focal length (BFL). BFL is the optical axis distance from the image sensor 300 to the center of the sensor side surface of the last lens. Specifically, if 2.5 < L7S2_max_sag to the sensor < 3.0 is satisfied, the manufacturing convenience and the reduction of TTL are easier.

[0378] [Mathematical Expression 8]

[0379] 1 < CT1 / CT7 < 3

[0380] In the mathematical expression 8, CT1 is the center thickness of the first lenses 101 and 201, and CT7 is the center thickness of the seventh lenses 107 and 207. When the mathematical expression 8 is satisfied, the aberration characteristics can be improved, and the influence on the reduction of the optical system can be set. In the first embodiment and the second embodiment, the mathematical expression 8 can preferably satisfy 1 < CT1 / CT7 < 2. The mathematical expression 8 can set the object side lens and the sensor side lens of the optical system as glass lenses and plastic lenses, and limit the difference in their center thicknesses. Therefore, the chromatic aberration of the optical system can be improved, good optical performance can be achieved at the set viewing angle, and the total track length (TTL) can be controlled.

[0381] [Mathematical Expression 9]

[0382] 1 < CT45 / CT6 < 5

[0383] In the mathematical expression 9, CT45 is the center thickness of the fourth lenses 104, 204 and the fifth lenses 105 and 205, for example, the center thickness of the cemented lens 145, and CT6 is the center thickness of the sixth lenses 106 and 206. When the optical system satisfies the mathematical expression 9, the thicknesses of the cemented lens 145 and the adjacent sixth lenses 106 and 206 can be set to improve the aberration characteristics. In the first embodiment and the second embodiment, the mathematical expression 9 can preferably satisfy 1 < CT45 / CT6 < 3 or 1.5 < CT45 / CT6 < 2.5. CT45 can be greater than the center thickness (CT1 to CT7) of each of the first lens to the seventh lens. Here, the condition CT45 > ET45 can be satisfied.

[0384] [Mathematical Expression 10]

[0385] 0.5 < CT45 - ET45 < 1

[0386] In Mathematical Expression 10, CT45 is the central thickness of the fourth lenses 104 and 204 and the fifth lenses 105 and 205, for example, the central thickness of the cemented lens 145, and ET45 is the optical axis distance from the end of the effective area on the object side surface of the fourth lenses 104 and 204 to the end of the effective area on the sensor side surface of the fifth lenses 105 and 205. When the optical system satisfies Mathematical Expression 10, the central thickness and edge thickness of the cemented lens can be set to improve the aberration characteristics. In the first and second embodiments, Mathematical Expression 10 can preferably satisfy 0.5 ≤ CT45 / ET45 < 0.5. ET45 can be greater than the edge thickness (ET1 to ET7) of each of the first lens to the seventh lens.

[0387] [Mathematical Expression 11]

[0388] 0 < CA_L1S1 / CA_L4S1 < 2

[0389] In Mathematical Expression 11, CA_L1S1 represents the effective diameter of the first surface S1 of the first lenses 101 and 201, and CA_L4S1 represents the effective diameter of the seventh surface S7 of the fourth lenses 104 and 204. When Mathematical Expression 11 is satisfied, the optical systems 1000 and 1500 can control the incident light and set the factors affecting aberration. In the first embodiment, Mathematical Expression 11 can preferably satisfy 1 < CA_L1S1 / CA_L4S1 < 1.5. In the second embodiment, Mathematical Expression 11 can preferably satisfy 1 < CA_L1S1 / CA_L4S1 < 1.2.

[0390] [Mathematical Expression 12]

[0391] 0 < CA_L7S2 / CA_L5S2 < 2

[0392] In Mathematical Expression 12, CA_L5S2 represents the effective diameter of the tenth surface S10 of the fifth lenses 105 and 205, and CA_L7S2 represents the effective diameter of the fourteenth surface S14 of the seventh lenses 107 and 207. When Mathematical Expression 12 is satisfied, the optical systems 1000 and 1500 can control the incident light path and set the factors of performance change according to CRA and temperature. Preferably, in the first embodiment, Mathematical Expression 12 can satisfy 0.5 < CA_L7S2 / CA_L5S2 < 1.5. In the second embodiment, Mathematical Expression 12 can satisfy 0.5 < CA_L7S2 / CA_L5S2 < 1.

[0393] [Mathematical Expression 13]

[0394] 0 < CA_L1S2 / CA_L2S1 < 2

[0395] In mathematical expression 13, CA_L1S2 represents the effective diameter of the second surface S2 of the first lenses 101 and 201, and CA_L2S1 represents the effective diameter of the third surface S3 of the second lenses 102 and 202. When mathematical expression 13 is satisfied, the optical systems 1000 and 1500 can control the light traveling to the first lens group LG1 and the second lens group LG2, and a factor affecting the reduction of the lens sensitivity can be set. In the first embodiment, mathematical expression 15 preferably satisfies 1 < CA_L1S2 / CA_L2S1 < 1.5. In the second embodiment, mathematical expression 15 preferably satisfies 0.5 < CA_L1S2 / CA_L2S1 < 1.2.

[0396] [Mathematical expression 14]

[0397] 0.5 < CA_L4S1 / CA_L5S2 < 2.5

[0398] In mathematical expression 14, CA_L4S1 represents the effective diameter of the seventh surface S7 of the fourth lenses 104 and 204, and CA_L5S2 represents the effective diameter of the tenth surface S10 of the fifth lenses 105 and 205. When the optical systems 1000 and 1500 satisfy mathematical expression 14, the size of the cemented lens can be set. In the first embodiment, mathematical expression 14 preferably satisfies 0.8 ≤ CA_L4S1 / CA_L5S2 < 1.5. In the second embodiment, mathematical expression 14 preferably satisfies 1 ≤ CA_L4S1 / CA_L5S2 < 1.5.

[0399] [Mathematical expression 15]

[0400] 2 < L3R1 / (CA_L3S1 / 2) < 5

[0401] In Mathematical Expression 15, L3R1 represents the radius of curvature of the object-side surfaces of the third lenses 103 and 203, and CA_L3S1 represents the effective diameter of the fifth surface S5 of the object sides of the third lenses 103 and 203. If the biconvex third lenses 103 and 203 satisfy Mathematical Expression 15, the optical systems 1000 and 1500 can improve chromatic aberration. If it is less than the lower limit value of Mathematical Expression 15, the occurrence of aberration of the fifth surface S5 increases, and if it is greater than the upper limit value, the occurrence of aberration of the fifth surface S5 decreases, but since the radius of curvature of the sixth surface S6 must be smaller, the occurrence of aberration increases at the sixth surface S6, which causes a problem of affecting the aberration of the fourth lenses 104, 204 to the seventh lenses 107 and 207. Preferably, in the first embodiment, the range of 2 < L3R1 / (CA_L3S1 / 2) < 4 can be satisfied. Preferably, in the second embodiment, the range of 3 < L3R1 / (CA_L3S1 / 2) < 4 can be satisfied. Since the radius of curvature of the sixth surface S6 can be designed to be large while reducing the aberration occurring in the fifth surface S5, it is easy to manufacture the third lenses 103 and 203. The aberration occurring in the optical system can be reduced, the manufacture of the third lenses 103 and 203 can be made easier, and the yield can be increased.

[0402] [Mathematical Expression 15-1] CA_L4 > CA_L5 > CA_L6 > CA_L7

[0403] [Mathematical Expression 15-2] CA_L7S1 < (ImgH * 2)

[0404] In Mathematical Expressions 15-1 to 15-2, CA_L4, CA_L5, CA_L6, and CA_L7 are the effective diameters (average effective diameters) of the fourth lenses 104, 204 to the seventh lenses 107 and 207, and ImgH is half of the diagonal length of the image sensor 300. Therefore, the optical path can be set to the area of the image sensor 300 through the effective diameters of the fourth lenses 104 and 204 to the seventh lenses 107 and 207. Since the fourth lenses 104, 204, the fifth lenses 105 and 205, and the seventh lenses 107 and 207 are plastic lenses with aspherical surfaces, and the sixth lenses 106 and 206 are glass lenses with spherical surfaces, the aberration between the lenses can be compensated for each other.

[0405] [Mathematical Expression 16]

[0406] 1 < CA_GL_AVER / CA_PL_AVER < 1.5

[0407] In Mathematical Expression 16, CA_GL_AVER represents the average effective diameter of the glass lens, and CA_PL_AVER represents the average effective diameter of the plastic lens. By setting the effective diameter size of the glass lens and the effective diameter size of the plastic lens in Mathematical Expression 16, the path of the incident light can be effectively guided. In the first and second embodiments, Mathematical Expression 16 can preferably satisfy 1 <CA_GL_AVER / CA_PL_AVER<1.3。

[0408] Here, nGL>nPL may be satisfied. nGL is the number of glass lenses, and nPL is the number of plastic lenses. In addition, a condition of nGL-nPL=0 or 1 may be satisfied.

[0409] [Mathematical expression 17]

[0410] 1.2≤GL_CA1_AVER / PL_CA1_AVER≤2

[0411] In Mathematical Expression 17, GL_CA1_AVER is an average value of effective diameters of object-side surfaces of lenses made of glass, for example, it is an average value of effective diameters of object-side surfaces of the first lens 101, 201, the second lens 102, 202, the third lens 103, 203, and the sixth lens 106 and 206. PL_CA1_AVER is an average value of effective diameters of object-side surfaces of lenses made of plastic, for example, it is an average value of effective diameters of object-side surfaces of the fourth lens 104, 204, the fifth lens 105, 205, and the seventh lens 107 and 207. Since the effective diameter size of the plastic lens is designed to be relatively small compared to the effective diameter size of the glass lens, Mathematical Expression 17 may be satisfied. In the first and second embodiments, Mathematical Expression 17 may preferably satisfy 1.3≤GL_CA1_AVER / PL_CA1_AVER≤1.8.

[0412] [Mathematical expression 18]

[0413] CG3 <CG5<CG1

[0414] In Mathematical Expression 18, CG1 may be a center gap between the first lens 101, 201 and the second lens 102 and 202, CG3 may be a center gap between the third lens 103, 203 and the fourth lens 104 and 204, and CG5 may be a center gap between the fifth lens 105, 205 and the sixth lens 106 and 206. When Mathematical Expression 18 is satisfied, the center gap between glass lenses having a relatively thick thickness may be reduced, thereby reducing TTL and improving optical performance in an edge portion of a field of view (FOV).

[0415] [Mathematical Expression 19]

[0416] 1 < CT7 / CG6 < 3

[0417] In Mathematical Expression 19, CG6 is the central gap or the optical axis distance between the sixth lenses 106, 206 and the seventh lenses 107 and 207. By setting the central thickness (CT7) of the seventh lenses 107 and 207 and the central gap between the sixth lens and the seventh lens in Mathematical Expression 19, the optical performance of the edge portion of the viewing angle can be improved. In the first embodiment, Mathematical Expression 19 may preferably satisfy 1.1 < CT7 / CG6 < 1.5. In the second embodiment, Mathematical Expression 19 may preferably satisfy 2 < CT7 / CG6 < 2.5.

[0418] [Mathematical Expression 20-1]

[0419] 5 < |F6 / F5| < 10

[0420] In Mathematical Expression 20-1, F5 is the focal length of the fifth lens 105, and F6 is the focal length of the sixth lens 106. In Mathematical Expression 20-1, the relationship between the focal length of the fifth lens 105 and the focal length of the sixth lens 106 can be set. In the optical system 1000, the absolute value of the focal length of the sixth lens 106 disposed on the sensor side with respect to the cemented lens 145 is formed to be the largest, and the absolute value of the focal length of the fifth lens 105 disposed on the sensor side of the cemented lens 145 is formed to be the smallest. By doing so, the incident efficiency can be improved, and the refractive power of the optical system can be adjusted to guide it to the image sensor 300. In the first embodiment, Mathematical Expression 20-1 may preferably satisfy 6 < |F6 / F5| < 9.

[0421] [Mathematical Expression 20-2]

[0422] 2(CG5 + CG6) < CT45

[0423] In Mathematical Expression 20-2, CT45 is the central thickness of the cemented lens 245. By arranging the central thickness of the cemented lens to be greater than twice the sum of the central gap (CG5) between the fifth lens and the sixth lens and the central gap (CG6) between the sixth lens and the seventh lens, the resolution and chromatic aberration can be improved, and the central gap can be reduced.

[0424] [Mathematical Expression 21]

[0425] 1 < CT1 / CT2 < 2

[0426] In Mathematical Expression 21, CT1 is the central thickness of the first lenses 101 and 201, and CT2 is the central thickness of the second lenses 102 and 202. By setting the central thickness (CT1) of the first lens to be thicker than the central thickness (CT2) of the second lens in Mathematical Expression 21, the factors affecting aberration can be controlled. Preferably, in the first and second embodiments, Mathematical Expression 21 can satisfy 1 < CT1 / CT2 < 1.5.

[0427] [Mathematical Expression 22]

[0428] 1 < L7R1 / CT7 < 200

[0429] In Mathematical Expression 22, L7R1 is the radius of curvature of the 13th surface (S13) of the seventh lenses 107 and 207, and CT7 is the central thickness of the seventh lenses 107 and 207. By setting the radius of curvature (L7R1) of the object-side surface of the seventh lenses 107 and 207 and the central thickness of the seventh lenses 107 and 207 in Mathematical Expression 22, the refractive power of the seventh lenses 107 and 207 can be controlled. Therefore, good optical performance can be achieved in the central and peripheral portions of the viewing angle. Preferably, in the first embodiment, Mathematical Expression 22 can satisfy 180 < L7R1 / CT7 < 200. Preferably, in the second embodiment, Mathematical Expression 22 can satisfy 5 < L7R1 / CT7 < 10.

[0430] [Mathematical Expression 23]

[0431] 0 < CT_Max / CG_Max < 5

[0432] In Mathematical Expression 23, CT_Max is the maximum central thickness among the lenses, and CG_Max is the maximum gap between adjacent lenses. When Mathematical Expression 23 is satisfied, the optical system can have good optical performance at the focal length under the set viewing angle, and the TTL can be reduced. In the first embodiment, Mathematical Expression 23 can preferably satisfy 0.1 < CT_Max / CG_Max < 0.5. In the second embodiment, Mathematical Expression 23 can preferably satisfy 2 < CT_Max / CG_Max < 4.

[0433] [Mathematical Expression 24]

[0434] 1 < ΣCT / ΣCG < 7

[0435] In Mathematical Expression 24, ΣCT is the sum of the center thicknesses of the lenses, and ΣCG is the sum of the gaps between adjacent lenses. When Mathematical Expression 24 is satisfied, the optical system can have good optical performance at the focal length under a set viewing angle, and TTL can be reduced. In the first embodiment, Mathematical Expression 24 can preferably satisfy 1<ΣCT / ΣCG<1.5. In the second embodiment, Mathematical Expression 24 can preferably satisfy 5<ΣCT / ΣCG<7.

[0436] [Mathematical expression 25]

[0437] 10<ΣIndex<20

[0438] In Mathematical Expression 25, ΣIndex refers to the sum of the refractive index at the d-line of each lens in a plurality of lenses. When Mathematical Expression 25 is satisfied, TTL can be controlled in the optical systems 1000 and 1500 in which plastic lenses and glass lenses are mixed, and improved resolution can be achieved. In addition, when the number of glass lenses is greater than the number of plastic lenses, and when the number of glass lenses having a relatively thick thickness is large, TTL and the sum of the refractive index can be set. In the first and second embodiments, Mathematical Expression 25 can preferably satisfy 10<ΣIndex<15.

[0439] [Mathematical expression 26]

[0440] 10<ΣAbb / ΣIndex<35

[0441] In Mathematical Expression 26, ΣAbb represents the sum of the Abbe numbers of each lens in a plurality of lenses. When Mathematical Expression 26 is satisfied, the optical systems 1000 and 1500 may have improved aberration characteristics and resolution. Mathematical Expression 26 may control optical characteristics by setting the sum of the Abbe numbers of the lenses and the sum of the refractive indices. In the first and second embodiments, Mathematical Expression 26 may preferably satisfy 20<ΣAbb / ΣIndex<30.

[0442] [Mathematical expression 27]

[0443] 1<ΣCT / ΣET<2

[0444] In Mathematical Expression 27, ΣCT is the sum of the center thickness of the lens, and ΣET is the sum of the edge thickness (i.e., the end of the effective area of ​​the lens). When Mathematical Expression 27 is satisfied, the optical system can have good optical performance at the focal length under a set viewing angle, and TTL can be reduced. In the first embodiment and the second embodiment, Mathematical Expression 27 can preferably satisfy 1<ΣCT / ΣET<1.5.

[0445] [Mathematical expression 28]

[0446] 1 < CA_L3S1 / CA_min < 2

[0447] In Mathematical Expression 28, CA_L3S1 is the effective diameter of the fifth surface S5 on the object side of the third lenses 103 and 203, and CA_Min represents the minimum effective diameter among the object-side surface and the sensor-side surface of the lens. When Mathematical Expression 28 is satisfied, the optical system can provide a thinner module while controlling the incident light and maintaining the optical performance. In the first embodiment, Mathematical Expression 28 can preferably satisfy 1.5 < CA_L2S1 / CA_min < 2. In the second embodiment, Mathematical Expression 28 can preferably satisfy 1 < CA_L2S1 / CA_min < 1.5.

[0448] [Mathematical Expression 29]

[0449] 1 < CA_max / CA_min < 3

[0450] In Mathematical Expression 29, CA_max represents the maximum effective diameter among the object-side surface and the sensor-side surface of the lens, and CA_Min represents the minimum effective diameter among the object-side surface and the sensor-side surface of the lens. When Mathematical Expression 29 is satisfied, the optical system can set the size of a thin and compact structure while maintaining the optical performance. In the first embodiment, Mathematical Expression 29 can preferably satisfy 1 < CA_max / CA_min < 2.5. In the second embodiment, Mathematical Expression 29 can preferably satisfy 1 < CA_max / CA_min < 2.

[0451] [Mathematical Expression 30]

[0452] 1 < CA_max / CA_Aver < 3

[0453] In Mathematical Expression 30, CA_max represents the maximum effective diameter among the object-side surface and the sensor-side surface of the lens, and CA_Aver represents the average of the effective diameters of the object-side surface and the sensor-side surface of the lens. When Mathematical Expression 30 is satisfied, the optical system can set the size of a thin and compact structure while maintaining the optical performance. In the first and second embodiments, Mathematical Expression 30 can preferably satisfy 1 < CA_max / CA_Aver < 1.5.

[0454] [Mathematical Expression 31]

[0455] 0.5 < CA_min / CA_Aver < 1

[0456] In Mathematical Expression 31, CA_Min represents the minimum effective diameter of the object side surface and the sensor side surface of the lens, and CA_Aver represents the average value of the effective diameters of the object side surface and the sensor side surface of the lens. When Mathematical Expression 31 is satisfied, the optical system can be set to a size of a slim and compact structure while maintaining optical performance. In the first and second embodiments, Mathematical Expression 31 can preferably satisfy 0.5 <CA_min / CA_Aver<0.8。

[0457] [Mathematical expression 32]

[0458] 1 <CA_max / (2*ImgH)<3

[0459] Mathematical expression 32, CA_max represents the maximum effective diameter among the object side surface and the sensor side surface of the lens, and ImgH represents the diagonal length from the optical axis of the image sensor 300. When mathematical expression 32 is satisfied, the optical system can maintain good optical performance and set the size of a slim and compact structure. In the first and second embodiments, mathematical expression 32 may preferably satisfy 1 <CA_max / (2*ImgH)<2。

[0460] [Mathematical expression 33]

[0461] 1 <TD / CA_max<4

[0462] In Mathematical Expression 33, TD is the optical axis distance from the center of the object side surface of the first lens 101 and 201 to the center of the sensor side surface of the last lens, and CA_max represents the maximum effective diameter among the object side surface and the sensor side surface of the lens. When Mathematical Expression 33 is satisfied, the total optical axis distance and the maximum effective diameter of the lens can be set so that the size of good optical performance can be set. In the first embodiment and the second embodiment, Mathematical Expression 33 can preferably satisfy 2 <TD / CA_max<3。

[0463] [Mathematical expression 34]

[0464] 0 <F / L1R1<1

[0465] In Mathematical Expression 34, F is the effective focal length of the optical system, and L1R1 is the radius of curvature of the object-side surface of the first lenses 101 and 201. When Mathematical Expression 34 is satisfied, the influence on incident light and TTL can be controlled. In the first and second embodiments, Mathematical Expression 34 may preferably satisfy 0.5≤F / L1R1<1.

[0466] [Mathematical expression 35]

[0467] 1 < Max_th / Min_th < 3

[0468] In mathematical expression 35, Max_th is the thickness of the thickest region of the lens, and Min_th is the thickness of the thinnest region of the lens. The thickest thickness Max_th of the lens can be the center thickness (CT) of the lens, and the thinnest thickness Min_th of the lens can be the edge thickness (ET) of the lens, but the opposite is also possible. The thickest thickness Max_th of the lens can be the edge thickness (ET) of the lens, and the thinnest thickness Min_th of the lens can be the center thickness (CT) of the lens. The edge thickness (ET) refers to the thickness at the end of the effective diameter. When mathematical expression 35 is satisfied, the optical system can control the influence on the effective focal length. In the first embodiment, mathematical expression 35 can preferably satisfy the condition of 1 < MAX_th / MIN_th ≤ 2. In the second embodiment, mathematical expression 35 can preferably satisfy the condition of 2 < MAX_th / MIN_th ≤ 3.

[0469] Here, the ratio of the maximum thickness to the minimum thickness of the plastic lens can satisfy the following conditions. Max_PL_th is the thickness value of the thickest region of the plastic lens, and Min_PL_th is the thickness value of the thinnest region of the plastic lens. Max_PL_th can be the center thickness (CT) of the plastic lens, and Min_PL_th can be the edge thickness (ET) of the plastic lens. The edge thickness (ET) refers to the thickness at the end of the effective diameter. The opposite is also possible. Max_PL_th can be the edge thickness (ET) of the plastic lens, and Min_PL_th can be the center thickness (CT) of the plastic lens. The edge thickness (ET) refers to the thickness at the end of the effective diameter.

[0470] Condition 1: 1 < Max_PL_th / Min_PL_th < 2.5

[0471] If it is less than the lower limit value of the range of Condition 1, it is difficult to manufacture the plastic lens. That is, it is manufactured by injecting high-temperature resin and curing the resin at low temperature, but if the thickness difference is large, the shrinkage will be uneven when the lens is cooled at low temperature, which may lead to a high surface defect rate. In addition, if it is greater than the range of Condition 1, when the temperature changes from -40 degrees to 105 degrees and 205 degrees, the plastic lens shrinks and expands, and during this process, the change rate of the lens shape seems to be large, which may deteriorate the optical performance.

[0472] Preferably, it can satisfy the conditions of 1.0 < Max_PL_th / Min_PL_th < 1.8 and 1.0 < Max_PL_th / Min_PL_th < 1.5.

[0473] [Mathematical Expression 36]

[0474] 0 < EPD / |L1R1| < 1

[0475] In Mathematical Expression 36, EPD represents the size (mm) of the entrance pupil of the optical systems 1000 and 1500, and L1R1 represents the radius of curvature of the first surface S1 of the first lenses 101 and 201. When the optical systems 1000 and 1500 according to the embodiments satisfy Mathematical Expression 36, the optical systems 1000 and 1500 can control the incident light. In the first embodiment and the second embodiment, Mathematical Expression 36 can preferably satisfy the condition of 0.3 < EPD / |L1R1| ≤ 0.9.

[0476] [Mathematical Expression 37]

[0477] Po4 * Po5 < 0

[0478] In Mathematical Expression 37, Po4 is the refractive power value of the fourth lenses 104 and 204, and Po5 is the refractive power value of the fifth lenses 105 and 205. That is, the refractive powers of the fourth lenses 104, 204 and the fifth lenses 105 and 205 have opposite refractive powers, so that aberration can be improved, and light can be effectively guided to the image sensor. When the condition of Po4 * Po5 > 0, the effect of improving chromatic aberration in the cemented lens is not significantly manifested.

[0479] [Mathematical Expression 38]

[0480] 30 < v4 - v5 < 40

[0481] In Mathematical Expression 38, v4 is the Abbe number of the fourth lenses 104 and 204, and V5 is the Abbe number of the fifth lenses 105 and 205. When Mathematical Expression 38 is satisfied, the Abbe number difference between at least two lenses forming the cemented lens can be maintained at a certain value or greater value, and chromatic aberration can be improved. In the first embodiment and the second embodiment, Mathematical Expression 38 can preferably satisfy 30 ≤ v4 - v5 ≤ 35. When the cemented lens is less than the lower limit value of Mathematical Expression 38, the improvement of the aberration characteristics of the optical system may be minimal. Therefore, when the Abbe number difference between the object-side lens and the sensor-side lens in the cemented lens is 30 or greater and 35 or less, the aberration characteristics can be improved.

[0482] [Mathematical Expression 39]

[0483] 0 < |F1| / F < 10

[0484] In Mathematical Expression 39, F is the effective focal length of the optical system, and F1 is the focal length of the first lenses 101 and 201. When Mathematical Expression 39 is satisfied, the TTL applied to the vehicle optical system can be set. In the first and second embodiments, Mathematical Expression 39 can preferably satisfy 1 < |F1| / F < 7.

[0485] [Mathematical Expression 40]

[0486] F_LG1 / F_LG2 < 0

[0487] In Mathematical Expression 40, F_LG1 is the focal length of the first lens group LG1, and F_LG2 is the focal length of the second lens group (F_LG2). The focal length of the first lens group can have a negative value, and the focal length of the second lens group can have a positive value. When Mathematical Expression 40 is satisfied, the optical systems 1000 and 1500 can improve aberration characteristics such as chromatic aberration and distortion aberration. In the first embodiment, Mathematical Expression 40 can preferably satisfy 5 < |F_LG1 / F_LG2| < 8. In the second embodiment, Mathematical Expression 40 can preferably satisfy 8 < |F_LG1 / F_LG2| < 12.

[0488] [Mathematical Expression 41]

[0489] 0.1 < nGL / nPL < 2

[0490] In Mathematical Expression 41, nGL represents the number of glass lenses, and nPL represents the number of plastic lenses. By arranging the number of glass lenses in Mathematical Expression 41 to be greater than 1 times and less than 2 times the number of plastic lenses, the thickness of the optical system can be reduced, and a wide range of refractive powers can be provided by aspherical surfaces. In the first embodiment, Mathematical Expression 41 can preferably satisfy 1 < nGL / nPL < 1.5. In the second embodiment, Mathematical Expression 41 can preferably satisfy 0.1 < nGL / nPL < 1.

[0491] [Mathematical Expression 42]

[0492] CA_L7 ≤ CA_L3 < CA_L1

[0493] In Mathematical Expression 42, CA_L1 is an average effective diameter of the object-side surface and the sensor-side surface of the first lenses 101 and 201, CA_L3 is an average effective diameter of the object-side surface and the sensor-side surface of the third lenses 103 and 203, and CA_L7 is an average effective diameter of the object-side surface and the sensor-side surface of the seventh lenses 107 and 207. When Mathematical Expression 42 is satisfied, the first lens group and the second lens group may be provided, and aberrations may be improved by the first lens of the second lens group LG2. CA_L1 may have the maximum effective diameter in the optical system.

[0494] [Mathematical expression 43]

[0495] 0<ΣPL_CT / ΣGL_CT<1

[0496] In mathematical expression 43, ΣPL_CT is the sum of the center thickness of the plastic lens (or multiple plastic lenses), and ΣGL_CT is the sum of the center thickness of the glass lens. When mathematical expression 43 is satisfied, the overall TTL can be controlled by setting the thickness relationship of the plastic lens and the glass lens relative to the TTL. In the first embodiment, mathematical expression 43 may preferably satisfy 0.3<ΣPL_CT / ΣGL_CT<0.8. In the second embodiment, mathematical expression 43 may preferably satisfy 0.5<ΣPL_CT / ΣGL_CT<1.

[0497] [Mathematical expression 44]

[0498] 0<ΣPL_Index / ΣGL_Index<2

[0499] In mathematical expression 44, ΣPL_Index is the sum of the refractive indices of the plastic lens (or multiple plastic lenses) at the d-line, and ΣGL_Index is the sum of the refractive indices of the glass lens at the d-line. When mathematical expression 44 is satisfied, the refractive index relationship between the plastic lens and the glass lens can be set to control the overall resolution. In the first embodiment, mathematical expression 44 may preferably satisfy 0.5<ΣPL_Index / ΣGL_Index<1. In the second embodiment, mathematical expression 44 may preferably satisfy 1<ΣPL_Index / ΣGL_Index<1.5.

[0500] [Mathematical expression 45]

[0501] 10 <TTL<45

[0502] In mathematical expression 45, the total track length (TTL) refers to the distance (mm) on the optical axis OA from the center of the first surface S1 of the first lenses 101 and 201 to the upper surface of the image sensor 300. By making the TTL in mathematical expression 45 exceed 10 or 20, a vehicle optical system can be provided. In the first and second embodiments, mathematical expression 45 can preferably satisfy the condition of 30 < TTL ≤ 40 or TD < TTL.

[0503] [Mathematical expression 46]

[0504] 2 < ImgH < 10

[0505] Mathematical expression 46 can set the diagonal size (2 * ImgH) of the image sensor 300 and provide an optical system with a vehicle sensor size. In the first and second embodiments, mathematical expression 46 can preferably satisfy 4 ≤ ImgH < 6.

[0506] [Mathematical expression 47]

[0507] 1 < BFL < 3.5

[0508] In mathematical expression 47, BFL is the optical axis distance from the image sensor 300 to the center of the sensor side of the last lens. When mathematical expression 47 is satisfied, the installation space for the filter 500 and the cover glass 400 can be ensured, the assembly property of components can be improved through the gap between the image sensor 300 and the last lens, and the connection reliability can be enhanced. In the first and second embodiments, mathematical expression 47 can preferably satisfy 1.5 ≤ BFL ≤ 3. When BFL is less than the range of mathematical expression 47, some of the light traveling to the image sensor may not be transmitted to the image sensor, which may lead to a reduction in resolution. When BFL exceeds the range of mathematical expression 47, stray light may be introduced, which may deteriorate the aberration characteristics of the optical system.

[0509] [Mathematical expression 48]

[0510] 3 < F < 40

[0511] Mathematical expression 48 can set the total focal length (F) suitable for the vehicle optical system. In the first and second embodiments, mathematical expression 48 can preferably satisfy 5 < F < 20.

[0512] [Mathematical expression 49]

[0513] FOV < 45

[0514] In Mathematical Expression 49, the field of view (FOV) refers to the viewing angle (degree) of the optical systems 1000 and 1500, and may provide a vehicle optical system of less than 45 degrees. In the first and second embodiments, the FOV may preferably satisfy 20≤FOV≤40.

[0515] [Mathematical expression 50]

[0516] 1 <TTL / CA_max<5

[0517] In mathematical expression 50, CA_max refers to the largest effective diameter (mm) among the object-side surface and the sensor-side surface of the plurality of lenses, and the total track length (TTL) refers to the distance (mm) from the vertex of the first surface S1 of the first lens 101 and 201 to the upper surface of the image sensor 300 on the optical axis OA. Mathematical expression 50 sets the relationship between the total optical axis length and the maximum effective diameter of the optical system to provide an improved vehicle optical system. In the first and second embodiments, mathematical expression 50 may preferably satisfy 1.5 <TTL / CA_max≤3。

[0518] [Mathematical expression 51]

[0519] 2 <TTL / ImgH<10

[0520] In mathematical expression 51, total track length (TTL) refers to the distance (mm) from the vertex of the first surface S1 of the first lens to the upper surface of the image sensor 300 on the optical axis OA, and ImgH refers to the diagonal size of the image sensor 300. When mathematical expression 51 is satisfied, the optical systems 1000 and 1500 can have TTL applied to the vehicle image sensor 300, thereby providing further improved image quality. In the first and second embodiments, mathematical expression 51 can preferably satisfy 4 <TTL / ImgH<10。

[0521] [Mathematical expression 52]

[0522] 0.1 <BFL / ImgH<1

[0523] In mathematical expression 52, BFL is the optical axis distance from the image sensor 300 to the center of the sensor side surface of the last lens, and ImgH refers to the diagonal size of the image sensor 300. When mathematical expression 52 is satisfied, the optical systems 1000 and 1500 can ensure a back focal length (BFL) of the size of the image sensor 300 for the application vehicle, set a gap between the last lens and the image sensor 300, and have good optical characteristics in the center and edge portions of the field of view (FOV). In the first and second embodiments, mathematical expression 52 may preferably satisfy 0.2 <BFL / ImgH<0.8。

[0524] [Mathematical expression 53]

[0525] 5 <TTL / BFL<20

[0526] In mathematical expression 53, the total track length (TTL) refers to the distance (mm) from the vertex of the first surface S1 of the first lens to the upper surface of the image sensor 300 on the optical axis OA, and BFL refers to the optical axis distance from the image sensor 300 to the center of the sensor side surface of the last lens. When mathematical expression 53 is satisfied, the optical systems 1000 and 1500 can ensure BFL. In the first and second embodiments, mathematical expression 53 can preferably satisfy 10 <TTL / BFL<15。

[0527] [Mathematical expression 54]

[0528] 1 <TTL / F<3

[0529] In mathematical expression 54, total track length (TTL) refers to the distance (mm) from the vertex of the first surface S1 of the first lens to the upper surface of the image sensor 300 on the optical axis OA, and F is the effective focal length of the optical system. Therefore, an optical system for a driver assistance system can be provided. In the first embodiment and the second embodiment, mathematical expression 54 may preferably satisfy 1.5≤TTL / F≤2.8 or 2≤TTL / F≤2.8. When the optical system (1000, 1500) according to the embodiment satisfies mathematical expression 54, the optical systems 1000 and 1500 can have an appropriate focal length within a set TTL range, and provide an optical system that can form an image while maintaining an appropriate focal length even when the temperature changes from a low temperature to a high temperature. If it is lower than the lower limit of mathematical expression 54, it is necessary to increase the refractive power of the lens, making it difficult to correct spherical aberration or distortion aberration. If it is higher than the upper limit of mathematical expression 54, the effective diameter or TTL of the lens becomes longer, which may cause the problem of enlarging the imaging lens system.

[0530] [Mathematical expression 55]

[0531] 3 <F / BFL<10

[0532] Mathematical expression 55 is a method in which F is an effective focal length of the optical system and BFL refers to an optical axis distance from the image sensor 300 to the center of the sensor side of the last lens. When mathematical expression 55 is satisfied, the optical systems 1000 and 1500 can have a set viewing angle and an appropriate focal length, and a vehicle optical system can be provided. In addition, the optical systems 1000 and 1500 can minimize the gap between the last lens and the image sensor 300, and therefore, can have good optical characteristics at the edge portion of the field of view (FOV). In the first embodiment and the second embodiment, mathematical expression 55 can preferably satisfy 3 <F / BFL<6。

[0533] [Mathematical expression 56]

[0534] 1 <F / ImgH<5

[0535] Mathematical expression 56 is an optical system in which F is an effective focal length and ImgH represents the diagonal size of the image sensor 300. Such optical systems 1000 and 1500 can have improved aberration characteristics over the size of the vehicle image sensor 300. In the first and second embodiments, mathematical expression 56 can preferably satisfy 2 <F / ImgH<4。

[0536] [Mathematical expression 57]

[0537] 1 <F / EPD<5

[0538] In mathematical expression 57, F is the effective focal length of the optical system, and EPD represents the size of the entrance pupil. Therefore, the overall brightness of the optical system can be controlled. In the first and second embodiments, mathematical expression 57 can preferably be set to 1 <F / EPD<2。

[0539] [Mathematical expression 58]

[0540] 0 <BFL / TD<0.3

[0541] Mathematical expression 58, where TD is the optical axis distance of the lenses of the optical systems 1000 and 1500, and BFL is the optical axis distance from the image sensor 300 to the center of the sensor side of the last lens. Thus, while controlling the overall size, the resolution of the optical system can be maintained. In the first and second embodiments, mathematical expression 58 preferably satisfies 0 < BFL / TD < 0.1. When the conditional value of BFL / TD is 0.1 or greater, BFL is designed to be large compared to TD, so that the size of the entire optical system becomes large, it is difficult to miniaturize the optical system, and the distance between the seventh lenses 107 and 207 and the image sensor becomes long, such that unnecessary light amount may be increased between the seventh lenses 107 and 207 and the image sensor, which causes problems such as deterioration of aberration characteristics that reduce the resolution.

[0542] [Mathematical expression 59]

[0543] 0 < EPD / ImgH / FOV < 0.2

[0544] Mathematical expression 59 can set the relationship between the incident pupil size (EPD), the length of half of the maximum diagonal length of the image sensor (ImgH), and the viewing angle. Thus, the overall size and brightness of the optical system can be controlled. In the first and second embodiments, mathematical expression 59 preferably satisfies 0 < EPD / ImgH / FOV < 0.1.

[0545] [Mathematical expression 60]

[0546] 5 < FOV / F# < 30

[0547] Mathematical expression 60 can set the relationship between the viewing angle of the optical system and the F-number (F#). In the first and second embodiments, mathematical expression 60 preferably satisfies 10 < FOV / F# < 25. Here, F# is set to 1.6 or less to provide a bright image.

[0548] [Mathematical expression 61]

[0549] 0.2 < CG1 / TTL < 0.6

[0550] In mathematical expression 61, CG1 refers to the optical axis gap between the first lens 101 and the second lens 102, and the total track length (TTL) refers to the distance (mm) from the vertex of the first surface S1 of the first lens to the upper surface of the image sensor 300 on the optical axis OA. Among the gaps between the lenses spaced apart in the optical system 1000, the gap between the first lens 101 and the second lens 102 may be the largest. When the optical system 1000 satisfies mathematical expression 61 and increases the gap between the first lens 101 and the second lens 102, the radius of curvature of the first lens 101 increases, thereby facilitating lens manufacturing while also having the effect of correcting chromatic aberration. In the first embodiment, mathematical expression 61 may preferably satisfy 0.3 <CG1 / TTL<0.5。

[0551] [Mathematical expression 62]

[0552] 5<|F2 / F5|<10

[0553] In Mathematical Expression 62, F2 is the focal length of the second lens 202, and F5 is the focal length of the fifth lens 205. In Mathematical Expression 62, the relationship between the focal length of the second lens 202 and the focal length of the fifth lens 205 may be set. In the optical system 1500, the absolute value of the focal length of the second lens 202 made of glass is formed to be maximum, and the absolute value of the focal length of the fifth lens 205 made of plastic is formed to be minimum, thereby improving the incident efficiency and controlling the refractive power between the lenses made of glass and plastic to guide them to the image sensor 300. In the second embodiment, Mathematical Expression 62 preferably satisfies 5<|F2 / F5|<8.

[0554] [Mathematical expression 63]

[0555] 2<|F2 / F3|<10

[0556] In Mathematical Expression 63, F2 is the focal length of the second lens 202, and F3 is the focal length of the third lens 203. The absolute value of the focal length of the second lens 202 made of glass in the optical system 1500 is formed to be maximum, and the absolute value of the focal length of the third lens 203 made of glass in the optical system 1500 is formed to be minimum except for the cemented lens 245, thereby improving the incident efficiency and controlling the refractive power between the lenses made of glass and plastic to guide them to the image sensor 300. In the second embodiment, Mathematical Expression 63 may preferably satisfy 2<|F2 / F3|<5.

[0557] [Mathematical expression 64]

[0558] 0.05<|sag_i / (CA_i / 2)|<0.2(i=S1,S2,S3,S4)

[0559] Mathematical expression 64 can set the relationship between the sag values ​​of the first to fourth surfaces S1, S2, S3, and S4 of the first lens 101, 201 and the second lens 102, 202 and the effective diameter (CA), and if the relationship is satisfied, the refractive power of the lens can be increased. Here, if mathematical expression 64 also satisfies the condition of n1>1.7, even if the curvature radius of the first lens 101, 201 and the second lens 102, 202 is not sharply designed within the effective diameter, the first lens and the second lens can gather light with sufficient focal power.

[0560] [Mathematical expression 65]

[0561]

[0562] In mathematical expression 65, Z may represent sag, which refers to the distance from any position on the aspherical surface to the vertex of the aspherical surface along the optical axis. Y may represent the distance from any position on the aspherical surface to the optical axis in a direction perpendicular to the optical axis. c may represent the curvature of the lens, and K may represent the cone constant. In addition, A, B, C, D, E, and F may represent aspherical constants.

[0563] The optical systems 1000 and 1500 according to the first and second embodiments may satisfy at least one or more of mathematical expressions 1 to 64. In this case, the optical systems 1000 and 1500 may have improved optical characteristics. Specifically, when the optical systems 1000 and 1500 satisfy at least one or more of mathematical expressions 1 to 64, the optical systems 1000 and 1500 may have improved resolution and improved aberration and distortion characteristics. In addition, the optical systems 1000 and 1500 may ensure a back focal length (BFL) for applying the vehicle image sensor 300, may compensate for degradation of optical characteristics due to temperature changes, and may minimize the gap between the last lens and the image sensor 300, thereby having good optical performance in the central and edge portions of the field of view (FOV).

[0564] Table 5 shows result values ​​of the above-mentioned Mathematical Expressions 1 to 64 in the optical systems 1000 and 1500 of the embodiment. Referring to Table 5, it can be seen that the optical systems 1000 and 1500 satisfy at least one, two or more, or three or more of Mathematical Expressions 1 to 64. Specifically, it can be seen that the optical systems 1000 and 1500 according to the embodiment satisfy all of Mathematical Expressions 1 to 64. Therefore, the optical systems 1000 and 1500 can have good optical performance in the central part and the edge part of the field of view (FOV), and can have excellent optical characteristics.

[0565] [Table 5]

[0566]

[0567]

[0568]

[0569] Fig.29 2 is an example of a plan view of a vehicle to which a camera module or an optical system according to an embodiment of the present invention is applied. Fig.29 , the vehicle camera system according to an embodiment of the present invention includes an image generation unit 11, a first information generation unit 12, second information generation units 21, 22, 23, 24, 25 and 26, and a control unit 14. The image generation unit 11 may include at least one camera module 31 provided in the own vehicle, and may capture images of the front of the own vehicle and / or the driver to generate images of the front or interior of the vehicle. The image generation unit 11 may use the camera module 31 to capture images of the front of the own vehicle and the surroundings of the own vehicle in one or more directions to generate images of the surroundings of the own vehicle. Here, the front image and the surrounding image may be digital images, and may include color images, black and white images, and infrared images. In addition, the front image and the surrounding image 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 provided in the own vehicle, and detects the front of the own vehicle to generate first detection information. Specifically, the first information generating unit 12 is provided in the own vehicle, and detects the position and speed of a vehicle located in front of the own vehicle, the presence and position of a pedestrian, and the like to generate first detection information.

[0570] 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 in specific preset situations, such as when the driver wants to change the driving lane of the own vehicle or when reversing, the stability of the vehicle operation can be improved. The first information generating unit 12 provides the first detection information to the control unit 14. The second information generating units 21, 22, 23, 24, 25 and 26 detect each side of the own vehicle and generate second detection information 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. Specifically, the second information generating units 21, 22, 23, 24, 25 and 26 may include at least one radar and / or camera device set in the own vehicle, and may detect the position and speed of the vehicle located on the side of the own vehicle or take an image. Here, the second information generating units 21, 22, 23, 24, 25 and 26 may be respectively set at the two corners in front of the own vehicle, the side mirrors, and the two corners at the rear center and the rear.

[0571] At least one information generating unit of these vehicle camera systems may be equipped with an optical system and a camera module having the optical system as described in the embodiments disclosed above, and may provide or process information acquired through the front, rear, each side or corner areas of the own vehicle to a user to achieve autonomous driving or protect the vehicle and objects from the surrounding environment for safety.

[0572] The optical system of the camera module according to the embodiment of the present invention can be installed in multiple units in the vehicle for safety adjustment, enhancing autonomous driving functions and increasing convenience. In addition, the optical system of the camera module is applied to the vehicle as a component for controlling such as a lane keeping assist system (LKAS), a lane departure warning system (LDWS) and a driver monitoring system (DMS). Such a vehicle camera module can achieve stable optical performance even under changes in ambient temperature, and can provide a module with competitive price, thereby ensuring the reliability of vehicle components.

[0573] The features, structures, effects, etc. described in the above embodiments are included in at least one embodiment and are not necessarily limited to one embodiment. In addition, the features, structures, effects, etc. shown in each embodiment can be combined or modified by a person skilled in the art to which the embodiments belong and implemented in other embodiments. Therefore, the contents related to such combinations and modifications should be interpreted as being included in the scope of the embodiments.

[0574] In addition, although the above has been described with reference to the embodiments, these are merely examples and do not limit the present invention, and those skilled in the art to which the present invention belongs will recognize that various modifications and applications not illustrated above are possible without departing from the basic characteristics of the present invention. For example, each component specifically shown in the examples can be modified and implemented. And, differences related to such modifications and applications should be interpreted as being included within the scope of the present invention as defined in the appended claims.

Claims

1. An optical system, comprising: The first lens to the seventh lens are arranged along the optical axis, Wherein, the first lens has negative (-) refractive power, The combined refractive power of the second lens to the seventh lens has positive (+) refractive power, and Among the first to seventh lenses, the second lens has the smallest effective diameter, and the first lens has the largest effective diameter.

2. The optical system according to claim 1, in, The fourth lens, the fifth lens and the seventh lens are made of plastic material, and Wherein, at least one of the first lens to the third lens and the sixth lens is made of glass material.

3. The optical system according to claim 1, in, The effective diameters of the sixth lens and the seventh lens are smaller than the effective diameter of the fifth lens.

4. The optical system according to claim 3, in, An object-side surface of the second lens has a flat surface.

5. The optical system according to any one of claims 1 to 3, in, Among the first to seventh lenses, a lens having a smallest absolute value of focal length is one lens among the third to fifth lenses.

6. The optical system according to claim 5, in, The absolute values ​​of the focal lengths of the third lens to the fifth lens satisfy the following conditional expression, <Conditional expression> |F3|≥|F4|≥|F5| (In the above conditional expressions, F3 is the focal length of the third lens, F4 is the focal length of the fourth lens, and F5 is the focal length of the fifth lens).

7. An optical system comprising: The first lens to the seventh lens are arranged along the optical axis, Wherein, the first lens has negative (-) refractive power, The combined refractive power of the second lens to the seventh lens has positive (+) refractive power, and Wherein, the effective diameter of the first lens is greater than the effective diameter of the third lens.

8. The optical system according to claim 7, in, The optical system includes a cemented lens in which a lens having a positive (+) refractive power and a lens having a negative (-) refractive power are cemented, and The cemented lens can be formed by two lenses from the third to fifth lenses that are arranged continuously.

9. The optical system according to claim 8, in, The cemented lens is made of plastic material, and Wherein, at least one of the first lens to the third lens and the sixth lens is made of glass material.

10. The optical system according to claim 7 or 8, in, Among the first to seventh lenses, the absolute value of the focal length of the fifth lens is the smallest, and the absolute value of the focal length of the sixth lens is the largest.

Images