Optical system and camera module

Abstract

An optical system according to an embodiment includes first to seventh lenses arranged along an optical axis, in which: the first lens has positive (+) or negative (-) refractive power, the second lens has positive (+) or negative (-) refractive power, the third lens has positive (+) refractive power, the fourth lens has positive (+) refractive power, the fifth lens has negative (-) refractive power, and the sixth lens has positive (+) refractive power, a seventh lens having negative (-) refractive power; the sixth lens and the seventh lens are plastic lenses; and the fifth lens among the first to seventh lenses has a minimum radius of curvature on the sensor side.

Description

TECHNICAL FIELD

[0001] The present application relates to an optical system for improving optical performance and a camera module including the same. BACKGROUND

[0002] An advanced driver assistance system (ADAS) is an advanced driver assistance system that assists a driver to drive, which is configured to sense a situation in front, judge the situation with respect to a sensed result, and control a behavior of a vehicle with respect to the situation judgment. For example, an ADAS sensor device detects a preceding vehicle and recognizes a lane. Thereafter, when a target lane, a target speed, and a front target are determined, an electric stability control (ESC), an engine management system (EMS), a motor-driven power steering (MDPS), etc. of the vehicle are controlled. Representatively, the ADAS can be implemented as an automatic parking system, a low-speed city driving assistance system, a blind spot warning system, etc.

[0003] A sensor device for detecting a situation in front in the ADAS includes a GPS sensor, a laser scanner, a front radar, a LIDAR, etc., and most representatively, a camera for photographing a photo of a front, a rear, and a side of a vehicle.

[0004] These cameras can be disposed outside or inside of a vehicle to detect a surrounding environment of the vehicle. In addition, the cameras can be disposed inside of the vehicle to detect a situation of a driver and a passenger. For example, the camera can photograph the driver at a position adjacent to the driver and detect a health state of the driver, whether the driver is drowsy, whether the driver is drunk, etc. In addition, the camera can photograph the passenger at a position adjacent to the passenger and detect whether the passenger is sleeping, a health condition, etc., and provide information about the passenger to the driver.

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

[0006] Therefore, there is a need for a new optical system and a camera that can solve the above problems. SUMMARY

[0007] TECHNICAL SUBJECT

[0008] Embodiments aim to provide an optical system and a camera module having enhanced optical characteristics.

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

[0010] Embodiments aim to provide an optical system and a camera module capable of preventing or minimizing changes in optical characteristics in a variety of temperature ranges.

[0011] Technical solutions

[0012] To solve the above technical problems, an optical system according to an embodiment of the present application includes first to seventh lenses disposed along an optical axis, wherein the first lens has a negative (-) refractive power, the second lens has a positive (+) refractive power, the sixth lens has a positive (+) refractive power, the seventh lens has a negative (-) refractive power, and a distance between the first lens and the second lens on the optical axis can be greater than a distance between the fifth lens and the sixth lens.

[0013] Among the first to seventh lenses, the effective diameter of the first lens can be the largest, and among the first to seventh lenses, the effective diameter of the fifth lens can be the smallest.

[0014] On the optical axis, the thickness of the fourth lens can be less than the thickness of the fifth lens.

[0015] Among the first to seventh lenses on the optical axis, the thickness of the fifth lens can be the largest.

[0016] On the optical axis, the distance between the first lens and the second lens can be greater than the thickness of the fifth lens.

[0017] On the optical axis, the first lens can have a meniscus shape convex toward the object side.

[0018] The following conditional expression can be satisfied. <Conditional Expression> 20 < TTL < 30 (In the conditional expression, TTL denotes a distance on the optical axis from an object side surface of the first lens to an upper surface of an image sensor).

[0019] The following conditional expression can be satisfied. <Conditional Expression> 0 < CT2 / CT1 < 1 (In the conditional expression, CT1 denotes a thickness of the first lens on the optical axis, and CT2 denotes a thickness of the second lens on the optical axis).

[0020] To solve the above technical problems, an optical system according to an embodiment of the present application includes first to seventh lenses disposed along an optical axis, wherein the first lens has a negative (-) refractive power, the second lens has a positive (+) refractive power, the third lens has a positive (+) refractive power, and a thickness of the first lens along the optical axis can be less than a thickness of the fifth lens.

[0021] Among the first to seventh lenses, the effective diameter of the first lens can be the largest, and among the first to seventh lenses, the effective diameter of the fifth lens can be the smallest.

[0022] Among the first to seventh lenses, the effective diameter of the first lens can be the largest, and among the first to seventh lenses, the effective diameter of the fifth lens can be the smallest.

[0023] Among the first to seventh lenses, the effective diameter of the first lens can be the largest, and among the first to seventh lenses, the effective diameter of the fifth lens can be the smallest.

[0024] The following conditional expression can be satisfied. <Conditional Expression> 0 < F / L1R1 < 1 (In the conditional expression, F denotes the total focal length of the optical system, and L1R1 denotes the radius of curvature on the object side of the first lens).

[0025] The following conditional expression can be satisfied. <Conditional Expression> 5 < TTL / ImgH < 8 (In the conditional expression, TTL denotes the distance on the optical axis from the object side surface of the first lens to the upper surface of the image sensor, and ImgH denotes 1 / 2 of the maximum diagonal length of the image sensor on the optical axis).

[0026] The following conditional expression can be satisfied. <Conditional Expression> 1.8 < n1 < 1.9 (In the conditional expression, n1 denotes the refractive index of the d line of the first lens).

[0027] To solve the above technical problem, an optical system includes first to seventh lenses disposed along an optical axis, wherein the first lens has positive (+) or negative (-) refractive power, the second lens has positive (+) or negative (-) refractive power, the third lens has positive (+) refractive power, the fourth lens has positive (+) refractive power, the fifth lens has negative (-) refractive power, the sixth lens has positive (+) refractive power, the seventh lens has negative (-) refractive power, the sixth lens and the seventh lens are plastic lenses, and among the first to seventh lenses, the radius of curvature of the sensor side surface of the fifth lens is the smallest.

[0028] Among the first to seventh lenses, the fifth lens can have the smallest focal length.

[0029] The fifth lens is a lens disposed adjacent to the object side of the plastic lens, and among the first to seventh lenses, the effective diameter of the sensor side surface of the fifth lens can be the smallest.

[0030] Among the first to seventh lenses, the fifth lens can have the smallest focal length.

[0031] The optical system includes a cemented lens, and a radius of curvature of not more than one surface among the object side surface and the sensor side surface of the first to seventh lenses other than a cemented lens surface of the cemented lens is larger than a radius of curvature of the object side surface of the first lens on the optical axis.

[0032] To solve the above-described technical problem, the optical system according to the present embodiment includes first to seventh lenses disposed along an optical axis, wherein the first lens has a positive (+) or negative (-) refractive power, the second lens has a positive (+) or negative (-) refractive power, the third lens has a positive (+) refractive power, the fourth lens has a positive (+) refractive power, the fifth lens has a negative (-) refractive power, the sixth lens has a positive (+) refractive power, and the seventh lens has a negative (-) refractive power.

[0033] The fourth lens and the fifth lens are cemented lenses, and among absolute values of angles of inclination of the object side surfaces and the sensor side surfaces of the first to seventh lenses, the maximum value of the absolute value of the angle of inclination of the object side surface of the first lens other than a cemented surface of the cemented lens can be the smallest. (Angle of inclination: normal slope at an arbitrary point on a lens surface)

[0034] Among the first to seventh lenses, a difference between a sag value of the object side surface of the first lens on the optical axis and a maximum sag value of the object side surface of the first lens can be the smallest.

[0035] To solve the above-described technical problem, the optical system according to the present embodiment includes first to seventh lenses disposed along an optical axis, wherein the third lens has a positive (+) refractive power, the fourth lens has a positive (+) refractive power, the fifth lens has a negative (-) refractive power, the sixth lens has a positive (+) refractive power, the seventh lens has a negative (-) refractive power, the fourth lens and the fifth lens are cemented lenses, an effective diameter of the first lens among the first to seventh lenses is the largest, and the following conditional expression can be satisfied. <Conditional Expression> 1.2 < CAL1 / ImgH < 1.5 (In the conditional expression, CAL1 is a size of the effective diameter of the first lens, and ImgH is 1 / 2 of a maximum diagonal length of the image sensor on the optical axis).

[0036] The following conditional expression can be satisfied. <Conditional Expression> 0.2 < CT45 / TTL < 0.22 (In the conditional expression, CT45 is a thickness of the cemented lens on the optical axis, and TTL is a distance between the image sensor and the first lens on the optical axis).

[0037] The following conditional expression can be satisfied. <Conditional Expression> 0.5 < ΣCT / TTL < 0.75 (In the conditional expression, ΣCT is the sum of the thicknesses of the first to seventh lenses on the optical axis, and TTL is the distance from the first lens to the image sensor on the optical axis).

[0038] Among the object side surfaces and the sensor side surfaces of the first to seventh lenses, there can be four or less lens surfaces having a curvature radius greater than 60 mm.

[0039] Among the object side surfaces and the sensor side surfaces of the first to seventh lenses, there can be four or more and five or less lens surfaces having a curvature radius less than 20 mm.

[0040] To solve the above-described technical problem, an optical system according to an embodiment includes first to seventh lenses disposed along an optical axis, wherein the first lens has a positive (+) or negative (-) refractive power, the second lens has a positive (+) or negative (-) refractive power, the third lens has a positive (+) refractive power, the fourth lens has a positive (+) refractive power, the fifth lens has a negative (-) refractive power, the sixth lens has a positive (+) refractive power, and the seventh lens has a negative (-) refractive power, wherein the first lens is an aspherical lens made of glass, and the sixth lens and the seventh lens are plastic lenses, and among the first to seventh lenses, the sensor side curvature radius of the fifth lens is the smallest, and the sensor side curvature radius of the fifth lens can be smaller than the object side curvature radius of the sixth lens.

[0041] To solve the above-described technical problem, an optical system according to an embodiment includes first to seventh lenses disposed along an optical axis, wherein the first lens has a negative (-) refractive power, the second lens has a positive (+) refractive power, the sixth lens has a positive (+) refractive power, the seventh lens has a negative (-) refractive power, and the thickness of the first lens on the optical axis can be greater than the thickness of the third lens.

[0042] On the optical axis, the distance between the first lens and the second lens can be smaller than the distance between the second lens and the third lens.

[0043] On the optical axis, the seventh lens can have a meniscus shape convex toward the object side.

[0044] On the optical axis, the thickness of the third lens can be smaller than the distance between the sixth lens and the seventh lens.

[0045] On the optical axis, the thickness of the second lens can be the smallest among the first to seventh lenses.

[0046] The third lens can have a positive (+) refractive power, the fourth lens can have a positive (+) refractive power, and the fifth lens can have a negative (-) refractive power.

[0047] The following conditional expression can be satisfied. <Conditional Expression> 20 < TTL < 30 (In the conditional expression, TTL denotes a distance on the optical axis from the object side surface of the first lens to the upper surface of the image sensor).

[0048] The following conditional expression can be satisfied. <Conditional Expression> 2 < CT1 / CT7 < 3 (In the conditional expression, CT1 denotes a thickness of the first lens on the optical axis, and CT7 denotes a thickness of the seventh lens on the optical axis).

[0049] To solve the above-described technical problem, an optical system according to an embodiment of the present application includes first to seventh lenses disposed along an optical axis, wherein the first lens has a negative (-) refractive power, the second lens has a positive (+) refractive power, the third lens has a positive (+) refractive power, and a distance on the optical axis between the first lens and the second lens can be smaller than a distance between the second lens and the third lens.

[0050] Among the first to seventh lenses, an effective diameter of the fifth lens can be the smallest.

[0051] On the optical axis, a thickness of the first lens among the first to seventh lenses can be the largest.

[0052] On the optical axis, a distance between the second lens and the third lens can be greater than a thickness of the sixth lens.

[0053] The following conditional expression can be satisfied. <Conditional Expression> 0 < F / |L1R1| < 1 (In the conditional expression, F denotes a total focal length of the optical system, and L1R1 denotes a radius of curvature of the object side of the first lens).

[0054] The following conditional expression can be satisfied. <Conditional Expression> 1.8 < n1 < 1.9 (In the conditional expression, n1 denotes a refractive index of the first lens at a d line).

[0055] The following conditional expression can be satisfied. <Conditional Expression> 1.8 < n2 < 1.9 (In the conditional expression, n2 denotes a refractive index at a d line of the second lens).

[0056] Advantageous Effects

[0057] The optical system and the camera module according to the embodiment can have enhanced optical characteristics. In detail, in the optical system according to the embodiment, a plurality of lenses can have a set thickness, refractive power, and a distance from an adjacent lens. Accordingly, the optical system and the camera module according to the embodiment can have enhanced MTF characteristics, aberration control characteristics, resolution characteristics, etc., in a set angle of view range, and can have good optical performance in an edge portion of the angle of view.

[0058] Further, the optical system and the camera module according to the embodiment can satisfy a set angle of view by mixing the plastic lens and the glass lens, and achieve excellent optical characteristics. Thereby, the optical system can provide a more slim vehicle camera module. Accordingly, the optical system and the camera module can be provided for various applications and devices, and can have excellent optical characteristics even in a severe temperature environment, such as when exposed to the outside of a vehicle or to a high temperature inside a vehicle in summer.

[0059] Further, the optical system and the camera module according to the embodiment can satisfy a set angle of view by mixing the plastic lens and the glass lens, and achieve excellent optical characteristics. Thereby, the optical system can provide a more slim vehicle camera module. Accordingly, the optical system and the camera module can be provided for various applications and devices, and can have excellent optical characteristics even in a severe temperature environment, such as when exposed to the outside of a vehicle or to a high temperature inside a vehicle in summer. BRIEF DESCRIPTION OF DRAWINGS

[0060] Figure 1 is a side sectional view of an optical system and a camera module having the optical system according to a first embodiment.

[0061] Figure 2 is a side sectional view for explaining a relationship between an nth lens and an (n-1)th lens of the optical system according to Figure 1

[0062] Figure 3 is a table showing aspherical coefficients of lenses in the optical system of Figure 1

[0063] Figure 4 is a table showing thicknesses of each lens and a pitch between adjacent lenses in the optical system of Figure 1

[0064] Figure 5 is a table showing sag values of lens surfaces of the first to seventh lenses in the optical system of Figure 1

[0065] Figure 6 is a table showing tilt angle values of lens surfaces of the first to seventh lenses in the optical system of Figure 1

[0066] Figure 7 is a table showing aspherical coefficients of lenses in the optical system of Figure 1 ​​​​​a table of the position of the image sensor in the optical system, a table of chief ray angle (CRA) data at room temperature, low temperature, and high temperature.

[0067] Figure 8 is a graph showing data of a diffraction modulation transfer function (MTF) of the optical system of Figure 1 at room temperature.

[0068] Figure 9 is a graph showing data of a diffraction MTF of the optical system of Figure 1 at low temperature.

[0069] Figure 10 is a graph showing data of a diffraction MTF of the optical system of Figure 1 at high temperature.

[0070] Figure 11 is a graph showing data of aberration characteristics of the optical system of Figure 1 at room temperature.

[0071] Figure 12 is a graph showing data of aberration characteristics of the optical system of Figure 1 at low temperature.

[0072] Figure 13 is a graph showing data of aberration characteristics of the optical system of Figure 1 at high temperature.

[0073] Figure 14 is a side sectional view of an optical system according to a second embodiment and a camera module having the optical system.

[0074] Figure 15 is a side sectional view for explaining a relationship between an n-th lens and an (n-1)-th lens according to Figure 14

[0075] Figure 16 is a table showing aspheric coefficients of lenses in the optical system of Figure 14

[0076] is a table showing thicknesses of each lens and a spacing between adjacent lenses in the optical system of Figure 17 Figure 14 is a table showing sag values of lens surfaces of the first lens to the seventh lens in the optical system of

[0077] Figure 18 Figure 14 is a table showing sag values of lens surfaces of the first lens to the seventh lens in the optical system of

[0078] Figure 19 is a table showing sag values of lens surfaces of the first lens to the seventh lens in the optical system of Figure 14 ​​​a table showing inclination angle values of lens surfaces of the first lens to the seventh lens in the optical system of

[0079] Figure 20 is a graph showing data of a chief ray angle (CRA) of an image sensor in the optical system of Figure 14

[0080] Figure 21 is a graph showing data of a diffraction modulation transfer function (MTF) at room temperature of the optical system of Figure 14

[0081] Figure 22 is a graph showing data of a diffraction MTF at low temperature of the optical system of Figure 14

[0082] Figure 23 is a graph showing data of a diffraction MTF at high temperature of the optical system of Figure 14

[0083] Figure 24 is a graph showing data of aberration characteristics at room temperature of the optical system of Figure 14

[0084] Figure 25 is a graph showing data of aberration characteristics at low temperature of the optical system of Figure 14

[0085] Figure 26 is a graph showing data of aberration characteristics at high temperature of the optical system of Figure 14

[0086] Figure 27 is a side sectional view of an optical system according to a third embodiment and a camera module having the optical system.

[0087] Figure 28 is a side sectional view for explaining a relationship between an n-th lens and an (n-1)-th lens according to Figure 27

[0088] Figure 29 is a table showing aspherical coefficients of lenses in the optical system of Figure 27

[0089] Figure 30 is a table showing thicknesses of each lens and a spacing between adjacent lenses in the optical system of Figure 27

[0090] Figure 31 is a table showing a relationship between a focal length and a lens diameter of each lens in the optical system of Figure 27 ​​​​​​​​​​a table showing the sag value of the lens surface of the first to seventh lenses in the optical system according to

[0091] Figure 32 is a table showing the sag value of the lens surface of the first to seventh lenses in the optical system according to Figure 27

[0092] Figure 33 is a table showing the position of the image sensor in the optical system according to Figure 27

[0093] Figure 34 is a graph showing the data of the diffraction modulation transfer function (MTF) at room temperature with respect to the optical system according to Figure 27

[0094] Figure 35 is a graph showing the data of the diffraction MTF at low temperature with respect to the optical system according to Figure 27

[0095] Figure 36 is a graph showing the data of the diffraction MTF at high temperature with respect to the optical system according to Figure 27

[0096] Figure 37 is a graph showing the data of the aberration characteristics at room temperature with respect to the optical system according to Figure 27

[0097] Figure 38 is a graph showing the data of the aberration characteristics at low temperature with respect to the optical system according to Figure 27

[0098] Figure 39 is a graph showing the data of the aberration characteristics at high temperature with respect to the optical system according to Figure 27

[0099] Figure 40 is a side sectional view of an optical system according to the fourth embodiment and a camera module having the optical system.

[0100] Figure 41 is a sectional view for explaining the relationship between the nth lens and the (n-1)th lens according to Figure 40

[0101] Figure 42 is a table showing the aspherical coefficients of the lenses in the optical system according to Figure 40

[0102] Figure 43 is a table showing the aspherical coefficients of the lenses in the optical system according to Figure 40 ​​​​​​​​​​a table showing the thickness of each lens and the interval between adjacent lenses in the optical system of

[0103] Figure 44 is a table showing the sag value of the lens surface of the first lens to the seventh lens in the optical system of Figure 40

[0104] Figure 45 is a table showing the tilt angle value of the lens surface of the first lens to the seventh lens in the optical system of Figure 40

[0105] Figure 46 is a table showing the position of the image sensor in the optical system according to Figure 40

[0106] Figure 47 is a graph showing the data of the diffraction modulation transfer function (MTF) at room temperature with respect to the optical system of Figure 40

[0107] Figure 48 is a graph showing the data of the diffraction MTF at low temperature with respect to the optical system of Figure 40

[0108] Figure 49 is a graph showing the data of the diffraction MTF at high temperature with respect to the optical system of Figure 40

[0109] Figure 50 is a graph showing the data of the aberration characteristics at room temperature with respect to the optical system of Figure 40

[0110] Figure 51 is a graph showing the data of the aberration characteristics at low temperature with respect to the optical system of Figure 40

[0111] Figure 52 is a graph showing the data of the aberration characteristics at high temperature with respect to the optical system of Figure 40

[0112] Figure 53 is a side sectional view of the optical system according to the fifth embodiment and a camera module having the same.

[0113] Figure 54 is a side sectional view for explaining the relationship between the nth lens and the (n-1)th lens according to Figure 53

[0114] Figure 55 is a table showing the thickness of each lens and the interval between adjacent lenses in the optical system of Figure 53 ​​​​​​​​​​a table of aspheric coefficients of lenses in the optical system of

[0115] Figure 56 is a table showing Figure 53 thicknesses of each lens of the optical system of

[0116] Figure 57 is a table showing Figure 53 values of sag of lens surfaces of the first to seventh lenses in the optical system of

[0117] Figure 58 is a table showing Figure 53 values of tilt angle of lens surfaces of the first to seventh lenses in the optical system of

[0118] Figure 59 is a table showing Figure 53 position of the image sensor in the optical system according to

[0119] Figure 60 is a graph showing Figure 53 data of the diffraction modulation transfer function (MTF) at room temperature of the optical system of

[0120] Figure 61 is a graph showing Figure 53 data of the diffraction MTF at low temperature of the optical system of

[0121] Figure 62 is a graph showing Figure 53 data of the diffraction MTF at high temperature of the optical system of

[0122] Figure 63 is a graph showing Figure 53 data of aberration characteristics at room temperature of the optical system of

[0123] Figure 64 is a graph showing Figure 53 data of aberration characteristics at low temperature of the optical system of

[0124] Figure 65 is a graph showing Figure 53 data of aberration characteristics at high temperature of the optical system of

[0125] Figure 66 is a side sectional view of the optical system according to the sixth embodiment and a camera module having the optical system.

[0126] Figure 67 is a table for explaining Figure 66a side cross-sectional view showing a relationship between an nth lens and an (n-1)th lens of the optical system of FIG.

[0127] Figure 68 is a table showing aspherical coefficients of lenses in the optical system of FIG. Figure 66

[0128] Figure 69 is a table showing thicknesses of each lens and spacings between adjacent lenses in the optical system of FIG. Figure 66

[0129] Figure 70 is a table showing sag values of lens surfaces of the first to seventh lenses in the optical system of FIG. Figure 66

[0130] Figure 71 is a table showing tilt angle values of lens surfaces of the first to seventh lenses in the optical system of FIG. Figure 66

[0131] Figure 72 is a table showing a position of an image sensor in the optical system of FIG. Figure 66

[0132] Figure 73 is a graph showing data of a diffraction modulation transfer function (MTF) at room temperature with respect to the optical system of FIG. Figure 66

[0133] Figure 74 is a graph showing data of a diffraction MTF at low temperature with respect to the optical system of FIG. Figure 66

[0134] Figure 75 is a graph showing data of a diffraction MTF at high temperature with respect to the optical system of FIG. Figure 66

[0135] Figure 76 is a graph showing data of aberration characteristics at room temperature with respect to the optical system of FIG. Figure 66

[0136] Figure 77 is a graph showing data of aberration characteristics at low temperature with respect to the optical system of FIG. Figure 66

[0137] Figure 78 is a graph showing data of aberration characteristics at high temperature with respect to the optical system of FIG. Figure 66

[0138] Figure 79 is an example of a vehicle having the optical system according to an embodiment of the present application.​​​​​​​​​​​ DETAILED DESCRIPTION

[0139] Hereinafter, preferred embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0140] However, the technical idea of the present application is not limited to some embodiments to be described, but can be implemented in various forms, and one or more of the constituent elements can be selectively combined or replaced between the embodiments within the scope of the technical idea of the present application.

[0141] Further, unless explicitly defined and described, the terms used in the embodiments of the present application, including technical and scientific terms, can be interpreted as meanings that can be commonly understood by one of ordinary skill in the art, and the commonly used terms (such as terms defined in a dictionary) can be interpreted in the meaning of the context of the relevant art.

[0142] Further, the terms used in the present specification are used to describe the embodiments, and are not intended to limit the present application.

[0143] In the present specification, unless specifically stated and described in the phrase, the singular form can include the plural form, and when described as "at least one of A and B and C (or more than one)", it can include one or more of all combinations that can be combined with A, B, and C.

[0144] Further, in describing the components of the embodiments of the present application, terms such as first, second, A, B, (a), and (b) can be used. These terms are only intended to distinguish the described components from other components, and the terms do not limit the nature, order or sequence of the described components.

[0145] Also, when a component is described as being "connected", "coupled", or "interconnected" to another component, the component not only directly connected, coupled, or interconnected to the other component, but can also include being "connected", "coupled", or "interconnected" by means of other components therebetween.

[0146] Further, when described as being "on (above)" or "under (below)" each component, "on (above)" or "under (below)" indicates not only including the case where the two components directly contact, but also including the case where one or more other components are formed or disposed between the two components. In addition, when expressed as "on (above)" or "under (below)", the meaning of not only upward direction but also downward direction with respect to one component can be included.

[0147] In the description of the present application, the "object side surface" can refer to a surface of the lens facing the object side with respect to the optical axis OA, and the "sensor side surface" can refer to a surface of the lens facing the imaging surface (image sensor) with respect to the optical axis. The "object side" can be the "object side surface", and the "sensor side surface" can be the "image side". The curvature radius, the center thickness, and the optical axis interval between the lenses described in the lens data table can represent values on the optical axis (unit: mm). The vertical direction can represent a direction perpendicular to the optical axis, and the end of the lens surface or the lens can represent an end of an effective area of the lens through which incident light passes. Depending on the measurement method or the like, the size of the effective diameter of the lens surface can have a measurement error of up to ±0.4 mm. The paraxial region represents a very narrow region near the optical axis, and is a region in which the distance of light falling from the optical axis OA is almost 0. Hereinafter, the meaning of the optical axis can include the center of each lens or a very narrow region near the optical axis.

[0148] The optical systems 1000, 1100, 1200, 1300, 1400, and 1500 according to the first to sixth embodiments of the present application can include five or more lenses. The optical systems 1000, 1100, 1200, 1300, 1400, and 1500 and the camera module having the same can be installed inside or outside a vehicle to monitor a driver or sense an external object or a lane. The material of the lenses can be selected from glass or plastic, and the linear expansion coefficient of glass is less than that of plastic. Accordingly, a glass lens is employed to suppress a change in the focal point imaging position due to a change in temperature. However, compared to a plastic lens, a glass lens is expensive, and there is a problem in that it is difficult to meet the requirement for low cost. Accordingly, the lenses in the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 need to have a configuration in which a glass lens and a plastic lens are mixed. By employing these plastic lenses, the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 can provide weight reduction and low cost by reducing the thickness of the plastic lenses, and due to the plastic lenses, good correction can be provided for various aberrations such as spherical aberration and chromatic aberration. In addition, since the plastic lenses can provide an aspherical lens, a distortion portion in a peripheral portion can be minimized.

[0149] The optical systems 1000, 1100, 1200, 1300, 1400, and 1500 can include n lenses, where the nth lens can be the last lens adjacent to the image sensor 700, and the (n-1)th lens can 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 can have a ratio of glass lenses to plastic lenses in a range of 5:2 to 5:3.

[0150] At least one lens closest to the object within the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 can be made of glass. Three or more lenses (for example, 3 to 5 lenses) closest to the object can be made of glass. Because the lenses made of glass have a smaller ratio of shrinkage and expansion than the lenses made of plastic when the temperature changes, the lenses made of glass can be disposed in a region adjacent to the outside within the lens barrel.

[0151] At least one lens closest to the image sensor 700 within the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 can be made of plastic. For example, at least two lenses closest to the image sensor 700 can be made of plastic, and preferably, at least two lenses adjacent to the image sensor 700 can be made of plastic. That is, since the nth lens and the (n-1)th lens in the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 are disposed as plastic lenses, various aberrations can be corrected with respect to the incident light of the image sensor 700.

[0152] Within the optical systems 1000, 1100, 1200, 1300, 1400, and 1500, lenses made of a plastic material can be sequentially disposed, and lenses made of a glass material can be sequentially disposed. Within the optical systems 1000, 1100, 1200, 1300, 1400, and 1500, the lenses made of a plastic material can be disposed between the lenses made of a glass material. Within the optical systems 1000, 1100, 1200, 1300, 1400, and 1500, the lenses made of a glass material can be disposed between the lenses made of a plastic material.

[0153] Each of the lenses 101-107, 201-207, 301-307, 401-407, 501-507, and 601-607 can have an object-side surface and a sensor-side surface. The lenses having an aspheric sensor-side surface and an aspheric object-side surface in the optical system can be more in number than plastic lenses. The lenses having a spherical sensor-side surface and a spherical object-side surface in the optical system 1000, 1100, 1200, 1300, 1400, and 1500 can be less in number than the lenses having aspheric surfaces on both surfaces. The optical systems 1000, 1100, 1200, 1300, 1400, and 1500 have more aspheric lenses than spherical lenses, and thus various aberrations can be corrected.

[0154] Among the lenses of the optical systems 1000, 1100, 1200, 1300, 1400, and 1500, the lens having the largest refractive index can be positioned adjacent to the object. The largest refractive index can be 1.7 or more. Chromatic dispersion of light incident through the lens having the largest refractive index can be increased, and the center thickness can be made thinner than the edge thickness. In addition, since the lens having the largest 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.

[0155] Among the optical systems 1000, 1100, 1200, 1300, 1400, and 1500, the lens having the largest effective diameter can be disposed at the center of the object side and the sensor side. The effective diameter of the lens can increase and decrease as it moves from the object side to the sensor side. The effective diameter of the lens can decrease and increase and then decrease again as it moves from the object side to the sensor side. Thus, since light incident in the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 is configured to move away from the optical axis and then converge back to the optical axis, the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 can form a stable optical path.

[0156] The effective diameter can be the diameter of an effective area on which effective light is incident from each lens. The effective diameter is a length in a direction (X, Y) orthogonal to the optical axis, and is an average of the effective diameter of the object-side surface and the effective diameter of the sensor-side surface of each lens. The "diameter of the lens surface" can refer to the "effective diameter of the lens". The "diameter of the lens" can be the diameter of the entire lens including a flange portion of the lens in addition to the effective area of the lens. Although the flange of the lens is not shown in the drawings, the flange can be a portion formed so as to protrude from the side surface of the lens in a direction perpendicular to the optical axis, so that the lens is coupled to the lens barrel. Effective light can not be incident on the flange. A spacer can be additionally provided between the flanges of different lenses, so that the lenses are coupled to the lens barrel.

[0157] Each of the lenses 101-107, 201-207, 301-307, 401-407, 501-507, and 601-607 can include an effective region and an ineffective region. The effective region can be a region through which light incident on each lens passes. In other words, the effective region can be defined as an effective region or effective diameter through which incident light is refracted to achieve an optical characteristic. The ineffective region can be disposed around the effective region. The ineffective region can be a region through which effective light does not pass incident on the plurality of lenses. In other words, the ineffective region can be a region that is irrelevant to the optical characteristic. Furthermore, an end portion of the ineffective region can be a region fixed to a lens barrel or the like that accommodates the lens.

[0158] Within the optical systems 1000, 1100, 1200, 1300, 1400, and 1500, the total top length (TTL) can be more than 5 times, for example, more than 6 times and less than 8 times, larger than Imgh. The total track length (TTL) is a distance on the optical axis OA from the center of the object side surface of the first lens to the upper surface of the image sensor 700. Imgh is half of the maximum diagonal length of the image sensor 500. Within the optical systems 1000, 1100, 1200, 1300, 1400, and 1500, the effective focal length (EFL) is set to 10 mm or more, and the angle of view FOV is set to less than 45 degrees, so that a standard optical system can be provided in a vehicle camera module. For example, the optical system and camera module according to the embodiments can be applied to a camera of an advanced driver assistance system (ADAS) provided inside or outside a vehicle.

[0159] The optical systems 1000, 1100, 1200, 1300, 1400, and 1500 can have a condition that TTL / Imgh is 5 or more and 8 or less (for example, 5 or more and 6.5 or less). By setting the optical systems 1000, 1100, 1200, 1300, 1400, 1500 to have a value of TTL / Imgh of 5 or more and 8 or less, a vehicle lens optical system can be provided. Thus, the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 can provide an image without exaggerating or distorting the image being formed.

[0160] An effective diameter of at least one plastic lens within the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 can be less than a length of the image sensor 700. The effective diameter is a diameter or length of an effective area on which light is incident. The length of the image sensor 700 is a maximum length of a diagonal line in a direction orthogonal to the optical axis OA. The number of lenses within the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 having an effective diameter greater than the length of the image sensor 700 can 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 700 can be less than 50% or less than 40%.

[0161] At least one cemented lens 145, 245, 345, 445, 545, and 645 can be included in the optical systems 1000, 1100, 1200, 1300, 1400, and 1500. The cemented lens 145, 245, 345, 445, 545, and 645 can be a lens in which at least two lenses having different refractive powers are cemented, and a gap between the two lenses can be less than 0.01 mm. The cemented lens 145, 245, 345, 445, 545, and 645 can be a lens in which two lenses having different focal lengths are cemented. The cementing of the two lenses can be bonded using an adhesive. An effective diameter of at least one lens or all lenses disposed on the object side with respect to the cemented lens 145, 245, 345, 445, 545, and 645 can be greater than the length of the image sensor 700. An effective diameter of at least one lens disposed on the sensor side with respect to the cemented lens 145, 245, 345, 445, 545, and 645 can be less than the length of the image sensor 700. Further, among the cemented lens 145, 245, 345, 445, 545, and 645, the object side lens 103, 203, 303, 403, 503, and 603 can be greater than the length of the image sensor 700, and the sensor side lens 104, 204, 304, 404, 504, and 604 can be greater than the length of the image sensor 700.

[0162] The lenses between the cemented lens 145, 245, 345, 445, 545, and 645 and the first lens 101, 201, 301, 401, 501, and 601 can be made of glass or plastic. The lenses disposed between the cemented lens 145, 245, 345, 445, 545, and 645 and the image sensor 700 can be made of plastic. The lenses between the cemented lens 145, 245, 345, 445, 545, and 645 and the first lens 101, 201, 301, 401, 501, and 601 can be both spherical lenses on both surfaces or both aspherical lenses on both surfaces. The lenses disposed between the cemented lens 145, 245, 345, 445, 545, and 645 and the image sensor 700 can be both aspherical lenses on both surfaces. The two surfaces are an object side surface and a sensor side surface. Thus, by disposing aspherical lenses between the cemented lens 145, 245, 345, 445, 545, and 645 and the image sensor 700, optical performance can be improved by correcting curvature aberration and chromatic aberration.

[0163] The lens unit can be a mixture of glass lenses and plastic lenses. The number of plastic lenses can be more than 60% of the total number of lenses, and can be in the range of 40% to 85% or 60% to 80%. Thus, when more plastic lenses are disposed within the camera module, the weight of the camera module can be reduced, and plastic materials make it easy to polish and process, are resistant to external impact, have high price competitiveness, and make it easy to secure materials. In addition, various aberrations can be corrected by plastic lenses, so that optical performance degradation can be prevented.

[0164] By mixing more plastic lenses into the optical systems 1000, 1100, 1200, 1300, 1400, and 1500, embodiments of the present application can reduce the weight of the camera module, provide lower manufacturing costs, suppress degradation of optical characteristics due to temperature changes, allow various types of plastic lenses to replace glass lenses, and lens surfaces such as aspherical surfaces or freeform surfaces can be easily polished and processed.

[0165] The lens unit 100, 200, 300, 400, 500, and 600 can include lenses of a first material and lenses of a second material disposed along an optical axis OA. The first material can be a glass material, and the second material can be a plastic material. The lenses of the first material can be disposed between the lenses of the second material. The lenses of the second material can be disposed between the lenses of the first material.

[0166] The lens units 100, 200, 300, 400, 500, and 600 can include a lens of a first material having an aspherical surface, a lens of the first material having a spherical surface, and a lens of a second material having an aspherical surface along the optical axis OA. The first material can be a glass material, and the second material can be a plastic material. The lens of the first material having a spherical surface can be disposed between the lenses of the second material having an aspherical surface. The lens of the second material can be disposed between the lens of the first material having an aspherical surface and the lens of the first material having a spherical surface.

[0167] An effective diameter of a lens closest to the object side within the lens units 100, 200, 300, 400, 500, and 600 can be greater than an effective diameter of a lens closest to the image sensor 700. Accordingly, the brightness of the optical system can be controlled. The effective diameter can be an average effective diameter of an object side surface and a sensor side surface of each lens. By controlling the effective diameter size of each lens, the optical systems 1000, 1100, 1200, 1300, 1400, and 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 systems 1000, 1100, 1200, 1300, 1400, and 1500.

[0168] The lens units 100, 200, 300, 400, 500, and 600 can include first lenses 101, 201, 301, 401, 501, and 601, second lenses 102, 202, 302, 402, 502, and 602, third lenses 103, 203, 303, 403, 503, and 603, fourth lenses 104, 204, 304, 404, 504, and 604, fifth lenses 105, 205, 305, 405, 505, and 605, sixth lenses 106, 206, 306, 406, 506, and 606, and seventh lenses 107, 207, 307, 407, 507, and 607 arranged from the object side to the sensor side along the optical axis.

[0169] Within the lens units 100, 200, 300, 400, 500, and 600, a focal length of a lens closest to the object can be greater than a focal length of a plastic lens when the focal length is an absolute value. Here, the plastic lens can be at least one lens disposed on the sensor side of a cemented lens, or at least one lens adjacent to the image sensor.

[0170] The lens units 100, 200, 300, 400, 500, and 600 can be disposed in a camera module having an inner lens barrel on one side or the entire inner surface of a lens barrel. The lens units 100, 200, 300, 400, 500, and 600 can be disposed in a camera module having a plurality of inner lens barrels surrounding different lenses of a lens barrel. The lens units 100, 200, 300, 400, 500, and 600 can be disposed in a camera module having a first inner lens barrel in contact with an outer surface of at least one lens of a lens barrel and a second inner lens barrel in contact with the outer surface of the at least one lens. The lens units 100, 200, 300, 400, 500, and 600 can be disposed in a camera module having a plurality of inner lens barrels each disposed between the outside of at least one or two or more lenses and a lens barrel. The lens units 100, 200, 300, 400, 500, and 600 can be disposed in a camera module in which the plurality of inner lens barrels are made of a material different from that of the lens barrel.

[0171] In the lenses constituting the lens units 100, 200, 300, 400, 500, and 600, at least a portion of a lens made of glass can be disposed in a lens barrel, and at least a portion of a lens made of plastic can be disposed in an inner lens barrel disposed inside the lens barrel. Thereby, the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 can maintain resolution according to temperature changes. The lens units 100, 200, 300, 400, 500, and 600 can be disposed in a camera module having different lens barrels to minimize the eccentricity of lenses, for example, plastic lenses expanding according to temperature changes. The lens barrel in which the lens units 100, 200, 300, 400, 500, and 600 are disposed has a plurality of inner lens barrels inside the lens barrel, thereby maintaining resolution of the optical system according to temperature changes and suppressing deformation of the lenses. Accordingly, the effective diameter of at least a portion of a glass material lens included in the lens units 100, 200, 300, 400, 500, and 600 can be smaller than the effective diameter of at least a portion of a plastic material lens.

[0172] Within the lens units 100, 200, 300, 400, 500, and 600, there can be at least one lens, for example, at least two lenses, having a larger average effective diameter than 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 of PLca_Aver < GLca_Aver can be satisfied. In addition, the condition of 1 < GLca_Aver / PLca_Aver < 1.5 can be satisfied. In addition, the relationship between the length of the image sensor 700 and the average effective diameter of the plastic lens PLca_Aver can satisfy the condition of 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 700 can satisfy the condition of 1.1 < GLca_Aver / (Imgh*2) < 1.5. It can be set so that the difference between the maximum length of the image sensor 700 and the effective diameter of the plastic lens can not be large. Thus, by arranging the plastic lens having a small effective diameter adjacent to the image sensor 700, the plastic lens can disperse color from the center portion to the edge portion of the image sensor 700.

[0173] 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 having the smallest effective diameter is made of plastic, and the lens having the largest effective diameter can be made of glass. Within the lens units 100, 200, 300, 400, 500, and 600, the smallest effective diameter 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 changes in optical performance due to temperature changes. In addition, the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 can improve resolution and chromatic aberration control characteristics by controlling incident light, and can improve vignetting characteristics of the optical systems 1000, 1100, 1200, 1300, 1400, and 1500.

[0174] The optical systems 1000, 1100, 1200, 1300, 1400, and 1500 or the camera module can include the image sensor 700. The image sensor 700 can detect light and convert it into an electrical signal. The image sensor 700 can detect light that has sequentially passed through the lens units 100, 200, 300, 400, 500, and 600. The image sensor 700 can include an element capable of detecting incident light, such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS).

[0175] Here, the number of lenses having an effective diameter greater than the length of the image sensor 700 can be 4 to 6, and the number of lenses having an effective diameter less than the length of the image sensor 700 can be 1 to 3.

[0176] The optical systems 1000, 1100, 1200, 1300, 1400, and 1500 or the camera module can include the optical filter 900. The optical filter 900 can be disposed between the last lens and the image sensor 700. The optical filter 900 can be disposed between the lens closest to the sensor side among the lenses of the lens units 100, 200, 300, 400, 500, and 600 and the image sensor 700. For example, the optical filter 900 can be disposed between the nth lens and the image sensor 700.

[0177] The cover glass 800 is disposed between the optical filter 900 and the image sensor 700 and protects the upper portion of the image sensor 192 and can prevent the reliability of the image sensor 700 from deteriorating. The cover glass 800 can be removed. The cover glass 800 can be a protective glass.

[0178] The optical filter 900 can include an infrared filter or an infrared cut filter (IR cut). The optical filter 900 can allow light of a set wavelength band to pass through and filter out light of a different wavelength band. When the optical filter 900 includes an infrared filter, it can block radiant heat emitted by external light from being transmitted to the image sensor 700. In addition, the optical filter 900 can allow visible light to pass through and reflect infrared light.

[0179] The optical systems 1000, 1100, 1200, 1300, 1400, and 1500 according to the embodiments can include an aperture stop. The aperture can adjust the amount of light incident on the optical systems 1000, 1100, 1200, 1300, 1400, and 1500. In a lens disposed between an object and the aperture, the effective diameter of the lens surface tends to increase from the object 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 refer to the case where the effective diameter of the lens surface increases or decreases. For example, it also includes the case where the effective diameter of the lens surface increases and then decreases as it travels from the aperture to the sensor side.

[0180] In the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 of the first to sixth embodiments, the sum of the refractive indices of the lenses of the lens units 100, 200, 300, 400, 500, and 600 can be 8 or more, for example, in the range of 8 to 15, and the average of the refractive indices can be in the range of 1.58 to 1.7. The sum of the Abbe numbers of each lens can be 270 or more, for example, in the range of 280 to 350, and the average of the Abbe numbers can be 50 or less, for example, in the range of 35 to 47. The sum of the center thicknesses of the entire lenses can be 20 mm or more, for example, in the range of 25 mm to 30 mm, and the average of the center thicknesses can be in the range of 3.5 mm to 4.0 mm. The sum of the center spacings between the lenses on the optical axis OA can be 3 mm or more, for example, in the range of 4 mm to 6 mm, and less than the sum of the center thicknesses of the lenses. Furthermore, the average of the effective diameters of each of the lens surfaces S1 to S14 of the lens units 100, 200, 300, 400, 500, and 600 can be set to 8 mm or more, for example, in the range of 8 mm to 15 mm.

[0181] In the optical system according to the first to sixth embodiments of the present application, the angle of view (diagonal line) can be 50 degrees or less, for example, in the range of 20 to 50 degrees. The F number of the optical system or the camera module can 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 embodiments of the present application, the maximum angle of view (diagonal line) can be 50 degrees or less, for example, in the range of 20 to 50 degrees. The vehicle optical system has a horizontal angle of view FOV_H in the Y-axis direction that can be greater than 20 degrees and less than 40 degrees, for example, in the range of 25 to 35 degrees. Further, the vertical angle of view is set at a smaller angle than the horizontal angle of view, and can 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 can be 8.064 mm ± 0.5 mm, and the sensor height in the vertical direction X can be 4.54 mm ± 0.5 mm. The horizontal field of view (FOV_H) is a field of view with respect to the horizontal length of the sensor. Thus, changes in the focal point imaging position according to temperature changes can be suppressed, and a vehicle camera in which various aberrations are well corrected can be provided.

[0182] Since the embodiments are optical systems applied to vehicle cameras, the first lenses 101, 201, 301, 401, 501, and 601 can be provided as glass materials, but they can also be designed to use plastic lenses and glass lenses together. This is because glass materials have the advantages of being resistant to scratches and not sensitive to external temperatures compared to plastic materials. The first lenses 101, 201, 301, 401, 501, and 601 can be glass molded lenses having an aspherical surface and made of a glass material. The glass molded lenses can be manufactured by placing an optical glass ingot inside a mold having an aspherical shape and through a heating and compression process.

[0183] In order to more effectively prevent scratches caused by foreign matter or due to structures provided inside the vehicle, glass lenses can be used as the first lenses 101, 201, 301, 401, 501, and 601, and the object side surface of the first lenses 101, 201, 301, 401, 501, and 601 can have a gently curved shape so as not to come into contact with external structures. This allows the occurrence of scratches due to contact with external structures to be minimized. For driver monitoring while the vehicle is driving, front / rear photography of the vehicle, or detection of lane detection and extraneous substances around the vehicle, the angle of view can be greater than 20 degrees and less than 40 degrees, for example, in the range of 25 to 35 degrees. This horizontal angle of view can be a preset angle of an advanced driver assistance system (ADAS).

[0184] The optical systems 1000, 1100, 1200, 1300, 1400, and 1500 according to the embodiments may further include a reflective member for changing the light path. The reflective member may be implemented as a prism that reflects light incident on the optical systems 1000, 1100, 1200, 1300, 1400, and 1500 toward the lens. Hereinafter, the optical systems according to the embodiments will be described in detail.

[0185] An optical system according to a first embodiment of the present invention will be described.

[0186] Figure 1 is a side sectional view of an optical system and a camera module having the same according to a first embodiment; Figure 2 Is used to explain the Figure 1 A side sectional view showing the relationship between the n-th lens and the (n-1)-th lens; Figure 3 It shows Figure 1 Table of aspheric coefficients of lenses in optical systems; Figure 4 It shows Figure 1 A table showing the thickness of each lens and the spacing between adjacent lenses in the optical system; Figure 5 It shows Figure 1 a table of sag values ​​of lens surfaces of first to seventh lenses in the optical system; Figure 6 It shows Figure 1 a table of inclination angle values ​​of lens surfaces of first to seventh lenses in the optical system; Figure 7 It shows that according to Figure 1 The position of the image sensor in the optical system, and the table of chief ray angle (CRA) data at room temperature, low temperature and high temperature; Figure 8 to Figure 10 Is to show about Figure 1 a graph of diffraction modulation transfer function (MTF) data of an optical system at room temperature, low temperature, and high temperature; and Figure 11 to Figure 13 Is to show about Figure 1 A graph showing the aberration characteristics of an optical system at room temperature, low temperature, and high temperature.

[0187] refer to Figure 1 and Figure 2 The optical system 1000 includes a lens unit 100, and the lens unit 100 may include first to seventh lenses 101 to 107. The first to seventh lenses 101 to 107 may be sequentially arranged along the optical axis OA of the optical system 1000. Light corresponding to object information may pass through the first to seventh lenses 101 to 107 and the optical filter 900 and be incident on the image sensor 700.

[0188] The first lens 101 can be disposed closest to the object side. The first lens 101 can be disposed farthest from the sensor side. The first lens 101 can have a negative (-) refractive power on the optical axis OA. The first lens 101 can include a plastic material or a glass material, and can be, for example, a glass material. The first lens 101 made of a glass material can reduce changes in a center position and a radius of curvature due to temperature changes according to a surrounding environment, and can protect an incident side surface of the optical system 1000.

[0189] The first surface S1 on the object side of the first lens 101 can be convex with respect to the optical axis, and the second surface S2 on the sensor side can be concave. The first lens 101 can have a meniscus shape convex toward the object side. The first lens 101 is made of glass and can have an aspherical surface. Aspherical coefficients of the first surface S1 and the second surface S2 can be provided as L1S1, L1S2 of the first lens 101. Figure 3 The first lens 101 can be manufactured as a lens having an aspherical surface by injection molding of a glass 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 within a mold having an aspherical shape and by a heating and compression process.

[0190] The first lens 101 is provided by an aspherical glass material such that a glass material having a high transmittance and a refractive index has an aspherical surface, which can reduce the number of lenses in the optical system. When the temperature becomes a low temperature or a high temperature, the aspherical glass material can maintain optical performance at a constant level due to the glass material. In addition, since the aspherical surface is applied to the glass material, the refractive index of light does not significantly change even if the lens is designed to be thin. Therefore, unlike an optical system in which the first lens is designed to be thickest in a horizontal viewing angle in the range of 30 to 50 degrees, the optical system of the present application can provide a thin first lens made of an aspherical glass material. Here, the thickness of the lens can include a center thickness and an edge thickness.

[0191] Further, the second lens 102 can be spaced apart further from the first lens 101 due to the refractive property of the first lens 101. That is, the center spacing between the first lens 101 and the second lens 102 within the lens unit can be the largest. Also, that is, the edge spacing between the first lens 101 and the second lens 102 within the lens unit can be the largest. The first surface S1 of the first lens 101 can have a critical point from the optical axis OA to the end of the effective region. When the first surface S1 has the critical point, it can be located in the range of 80% to 90%, preferably in the range of 82% to 87%, of the effective radius r11 from the optical axis OA. The critical point of the first surface S1 can be located in the range of 5.5 mm to 5.8 mm from the optical axis OA, preferably in the range of 5.6 mm to 5.7 mm from the optical axis.

[0192] The refractive index n1 of the first lens 101 can satisfy the condition of n1>1.8 or n1>1.82. Since the refractive index n1 of the first lens 101 is the largest in the lens unit 100, the curvature radius of the first lens 101 and the second lens 102 can be increased, and lens manufacturing can be easy. If the refractive index n1 of the first lens 101 is less than the condition, the lens surface must be formed sharply concave or convex to increase the refractive power of the first lens 101 and the second lens 102. In this case, lens manufacturing is not easy, the lens defect rate increases, and can cause a decrease in yield.

[0193] The second lens 102 can be disposed as the second from the object side. The second lens 102 can be disposed as the sixth from the sensor side. The second lens 102 can be disposed between the first lens 101 and the third lens 103. The second lens 102 can have a positive (+) refractive power on the optical axis OA. The second lens 102 can include a plastic or a glass material. For example, the second lens 102 can be provided by a glass material.

[0194] The object side third surface S3 of the second lens 102 can be convex and the sensor side fourth surface S4 can be convex with respect to the optical axis OA. The second lens 102 can have a shape in which both surfaces are convex. The second lens 102 is made of glass and can be spherical. At least one or both of the third surface S3 and the fourth surface S4 can be spherical.

[0195] Since the two surfaces of the second lens 102 are convexly disposed, it is possible to minimize the number of lenses and the TTL of the optical system, and to effectively refract light. Further, when the radius of curvature of the third surface S3 of the second lens 102 is L2R1 and the radius of curvature of the fourth surface S4 is L2R2, it is possible to satisfy the condition of L2R1 < |L2R2|. Thereby, light can be effectively refracted by the third surface S3 so that the effective diameter of the third lens 103 to the seventh lens 107 can be guided so as not to increase, and the TTL can be reduced. If L2R1 > |L2R2|, many aberrations can occur on the object side surface of the second lens 102, the refractive efficiency of light at the sensor side surface can be reduced, the effective diameter of the rear lens can increase, and the TTL can also become larger.

[0196] An aperture stop can be disposed around the sensor side fourth surface S4 of the second lens 102. The aperture can reduce the TTL in the field of view range, and can miniaturize the optical system. Therefore, it is possible to prevent a reduction in yield due to the weight of the optical system, and to improve production efficiency. Further, by reducing the TTL in the horizontal field of view (FOV_H) of 25 to 36 degrees, it is possible to miniaturize the optical system.

[0197] The third lens 103 can be disposed as the third from the object side. The third lens 103 can be disposed as the fifth from the sensor side. The third lens 103 can be disposed between the second lens 102 and the fourth lens 104. The third lens 103 can have a positive (+) refractive power on the optical axis OA. The third lens 103 can include a plastic or a glass material. For example, the third lens 103 can be provided by a glass material.

[0198] The object side fifth surface S5 of the third lens 103 can be convex, and the sensor side sixth surface S6 can be concave with respect to the optical axis. The third lens 103 can have a meniscus shape convex on the optical axis OA on the object side. The third lens 103 is made of glass and can be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 can be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0199] The fourth lens 104 can be disposed as the fourth from the object side. The fourth lens 104 can be disposed as the fourth from the sensor side. The fourth lens 104 can be disposed between the third lens 103 and the fifth lens 105. The fourth lens 104 can have a positive (+) or negative (-) refractive power on the optical axis OA. The fourth lens 104 can have a positive (+) refractive power. The fourth lens 104 can have a positive (+) refractive power different from that of the fifth lens 105. The fourth lens 104 can include a plastic or a glass material. For example, the fourth lens 104 can be provided by a glass material. The fourth lens 104 can be provided by the same material as the fifth lens 105.

[0200] The seventh surface S7 of the fourth lens 104 on the object side can be convex, and the eighth surface S8 on the sensor side can be concave with respect to the optical axis. The fourth lens 104 can have a meniscus shape convex toward the object side. The fourth lens 104 is made of glass and can have a spherical surface. At least one or both of the seventh surface S7 and the eighth surface S8 can be spherical. The seventh surface S7 and the eighth surface S8 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0201] The fifth lens 105 can be disposed as the fifth from the object side. The fifth lens 105 can be disposed as the third from the sensor side. The fifth lens 105 can be disposed between the fourth lens 104 and the sixth lens 106. The fifth lens 105 can have a positive (+) or negative (-) refractive power on the optical axis OA. The fifth lens 105 can have a negative (-) refractive power. The fifth lens 105 can have a negative (-) refractive power different from that of the fourth lens 104. The fifth lens 105 can include a plastic or a glass material. For example, the fifth lens 105 can be provided by a glass material. The fifth lens 105 can be provided by the same material as the fourth lens 104.

[0202] The ninth surface S9 of the fifth lens 105 on the object side can be convex, and the tenth surface S10 on the sensor side can be concave with respect to the optical axis. The fifth lens 105 can have a meniscus shape convex toward the object side from the optical axis OA. The fifth lens 105 is made of glass and can have a spherical surface. At least one of the ninth surface S9 and the tenth surface S10 can be a spherical surface. At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 105 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0203] The fourth lens 104 and the fifth lens 105 can be cemented. A bonding surface between the fourth lens 104 and the fifth lens 105 can be defined as an eighth surface S8. The eighth surface S8 can be the same surface as a ninth surface S9 of the fifth lens 105. An object side surface of the cemented lens 145 can be convex, and a sensor side surface can be concave. A spacing between the fourth lens 104 and the fifth lens 105 can be less than 0.01 mm, and can be attached with an adhesive. The spacing between the fourth lens 104 and the fifth lens 105 can be less than 0.01 mm from the optical axis OA to the end of the effective area. The fourth lens 104 and the fifth lens 105 can have opposite refractive powers. The composite refractive power of the fourth lens 104 and the fifth lens 105 can have a negative (-) refractive power.

[0204] A value of the radius of curvature of the cemented surface S8 of the cemented lens 145 can be less than 50. For example, the value of the radius of curvature of the cemented surface S8 of the cemented lens 145 can be less than 30. The cemented surface S8 of the cemented lens 145 can be formed in a gentle shape. Thereby, the cementing process of the fourth lens 104 and the fifth lens 105 forming the cemented lens 145 is advantageous, and the cementing retention strength can be increased.

[0205] A 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. A product of the focal length of the object side fourth lens 105 and the focal length of the sensor side fifth lens 105 of the cemented lens 145 can be less than 0. Accordingly, the aberration characteristics of the optical system can be improved. If the refractive powers of the two lenses of the cemented lens 145 are the same, there is a limit to the improvement in the aberration.

[0206] The composite refractive power of the cemented lens 145 has a negative (-) refractive power, and can have a negative (-) refractive power with respect to the third lens 103 on the object side and the sixth lens 106 on the sensor side of the cemented lens 145. Accordingly, the fourth lens 104, the cemented lens 145, and the fifth lens 105 can refract a portion of the incident light in the optical axis direction.

[0207] An effective diameter of the fourth lens 104 can be greater than a diagonal length of the image sensor 700. The effective diameter of the fourth lens 104 is an average of the effective diameters of the seventh surface S7 and the eighth surface S8, and can be greater than the diagonal length of the image sensor 700. An effective diameter of the fifth lens 105 can be less than the effective diameter of the fourth lens 104 and greater than the diagonal length of the image sensor 700. An effective diameter of the seventh surface S7 of the fourth lens 104 can be greater than the diagonal length of the image sensor 700, and an effective diameter of the tenth surface S10 of the fifth lens 105 can be less than the diagonal length of the image sensor 700.

[0208] When the fifth lens 105 is a spherical lens and the seventh lens 107 is an aspherical lens, a difference in effective diameter between the object side ninth surface S9 of the fifth lens 105 and the sensor side tenth surface S10 can be set to be the largest. For example, when the effective diameters of the ninth surface S9 and the sensor side tenth surface S10 of the fifth lens 105 are CA51 and CA52, a condition of CA51 > CA52 is satisfied, and a difference between CA51 and CA52 among the differences in effective diameter between the object side surface and the sensor side surface of each lens can be the largest. Accordingly, the difference in effective diameter between the object side surface and the sensor side surface of the fifth lens 105 can be set to be the largest in order to effectively guide light to travel through the aspherical lens having a relatively small effective diameter. Accordingly, a more slim optical system can be provided. The effective diameter of the fifth lens 105 can satisfy a condition of 1.1 < CA51 / CA52 < 1.5.

[0209] The cemented lens 145 is cemented with a glass lens having a different refractive index, has a spherical refractive surface, and at least one lens disposed closer to the sensor than the cemented lens 145 is an aspherical lens, so that spherical aberration can be compensated. In addition, at least one lens among the lenses disposed closer to the sensor than the cemented lens 145 is an aspherical lens and is disposed to have a small effective diameter, so that light can be effectively guided to travel through the aspherical lens to the image sensor 700. Since the cemented lens 145 is disposed between the aspherical lenses and between the spherical lenses, chromatic aberration correction can be more effective. By positioning the cemented lens 145 within the optical system, the TTL can be reduced.

[0210] The sixth lens 106 can be disposed as the sixth lens from the object side. The sixth lens 106 can be disposed as the second lens from the sensor side. The sixth lens 106 can be disposed between the fifth lens 105 and the seventh lens 107. The sixth lens 106 can have a positive (+) or negative (-) refractive power on the optical axis OA. The sixth lens 106 can have a positive (+) refractive power. The sixth lens 106 can include a plastic or a glass material. For example, the sixth lens 106 can be provided by a plastic material.

[0211] The sixth lens 106 can have a convex shape on the object side eleventh surface S11 and a convex shape on the sensor side twelfth surface S12 with respect to the optical axis. The sixth lens 106 can have a convex shape on both surfaces along the optical axis OA. At least one or both of the eleventh surface S11 and the twelfth surface S12 can be aspherical. Aspherical coefficients of the eleventh surface S11 and the twelfth surface S12 can be provided as Figure 4 L1 and L2 of L6.

[0212] The eleventh surface S11 of the sixth lens 106 can be configured to have no critical point from the optical axis OA to the end of the effective region. The twelfth surface S12 can be configured to have at least one critical point from the optical axis OA to the end of the effective region.

[0213] The seventh lens 107 can be configured to be closest to the sensor side. The seventh lens 107 can be configured to be farthest from the object side. The seventh lens 107 can have a positive (+) or negative (-) refractive power on the optical axis OA. The seventh lens 107 can have a negative (-) refractive power. The seventh lens 107 can include a plastic or glass material. For example, the seventh lens 107 can be made of a plastic material.

[0214] On the optical axis, the thirteenth surface S13 of the seventh lens 107 can be convex, and the fourteenth surface S14 of the sensor side can be concave. The seventh lens 107 can have a meniscus shape convex toward the object side. At least one of the thirteenth surface S13 and the fourteenth surface S14 can be an aspheric surface. For example, both the thirteenth surface S13 and the fourteenth surface S14 can be aspheric. The aspheric coefficients of the thirteenth surface S13 and the fourteenth surface S14 can be provided as S1 and S2 of L7 in Equation 1. Figure 3

[0215] The thirteenth surface S13 of the seventh lens 107 can have a critical point from the optical axis OA to the end of the effective region. When the thirteenth surface S13 has a critical point, it can be located in a range of 35% to 45% of the effective radius r71 from the optical axis OA, preferably in a range of 37% to 42% of the effective radius r71 from the optical axis OA. The critical point of the thirteenth surface S13 can be located in a range of 1.5 mm to 1.8 mm from the optical axis OA, preferably in a range of 1.6 mm to 1.7 mm from the optical axis OA. The thirteenth surface S13 having such a critical point can refract incident light to the center portion and the edge portion, and improve aberration.

[0216] The fourteenth surface S14 of the seventh lens 107 can have a critical point from the optical axis OA to the end of the effective region. When the fourteenth surface S14 has a critical point, it can be located in a range of 65% to 70% of the effective radius r72 from the optical axis OA, preferably in a range of 66% to 69% of the effective radius r72 from the optical axis OA. The critical point of the fourteenth surface S14 can be located in a range of 3 mm to 3.3 mm from the optical axis OA, preferably in a range of 3 mm to 3.1 mm from the optical axis OA.

[0217] ​The critical point of the thirteenth surface S13 and the fourteenth surface S14 is a point at which the sign of the slope value with respect to the optical axis OA and a direction perpendicular to the optical axis OA changes from positive (+) to negative (-) or from negative (-) to positive (+), and can represent a point at which the slope value is 0. Also, the critical point of the thirteenth surface S13 and the fourteenth surface S14 can be a point at which the slope value of the tangent line passing through the lens surface first increases and then decreases, or a point at which it first decreases and then increases.

[0218] The seventh lens 107 can be a plastic lens closest to the image sensor 700. Also, by arranging two or more plastic lenses adjacent to the image sensor 700, aberrations such as spherical aberration and chromatic aberration can be improved by the lens surface having an aspherical surface, and the influence on resolution can be controlled. Also, by arranging a plastic lens as the lens adjacent to the image sensor 700, it can be less sensitive to assembly tolerance than a glass lens. In other words, being less sensitive to assembly tolerance means that even if assembly is performed slightly differently from the design during assembly, the optical performance can not be significantly affected. Also, by providing two lenses 106 and 107 adjacent to the image sensor 700 with plastic, the optical performance can be improved by the lens surface having an aspherical surface, and for example, aberration characteristics can be improved and degradation of resolution can be prevented.

[0219] The sixth lens 106 and the seventh lens 107 are disposed to be spaced apart from each other, but can include the characteristics of a cemented lens. The sixth lens 106 and the seventh lens 107 can have opposite refractive powers. The product of the refractive power of the sixth lens 106 and the refractive power of the seventh lens 107 can be less than 0. The product of the focal length of the sixth lens 106 and the focal length of the seventh lens 107 can be less than 0. Accordingly, the aberration characteristics of the optical system can be improved. If the signs of the refractive powers of the two lenses having the characteristics of a cemented lens are the same, there is a limit to the improvement in aberration.

[0220] The sixth lens 106 and the seventh lens 107 can be made of the same material. The sixth lens 106 and the seventh lens 107 can be made of a plastic material. The sixth lens 106 and the seventh lens 107 can be made of the same material as the cemented lens 145.

[0221] [Table 1]

[0222]

[0223]

[0224] Table 1 shows surface numbers (surfaces), radii of curvature (radii), center thicknesses or distances between lens surfaces (thicknesses) of each lens, refractive indices (nd), Abbe numbers (vd), effective radii (half aperture diameters), and focal lengths (focal lengths) of lenses according to the first embodiment of the present application. At this time, units of the radii of curvature and the thicknesses or distances can be mm.

[0225] [Table 2]

[0226]

[0227]

[0228] Table 2 shows categories of the above mathematical expressions in the optical system 1000 of the embodiment, including a total top length (TTL) (mm) of the optical system 1000, a back focal length (BFL), an effective focal length F (mm), ImgH (mm), an effective diameter CA (mm), a thickness (mm), a TTL (mm), TD (mm) which is an optical axis distance from the first surface S1 to the fourteenth surface S14, composite focal lengths F2_7, F3_7, F4_7, F5_7, F6_7, and F4_5 (mm) of the first lens to the seventh lens, a sum of refractive indices, a sum of Abbe numbers, a sum of thicknesses (mm), a sum of spacings between adjacent lenses, an effective diameter characteristic, a sum of refractive indices of glass lenses, a sum of refractive indices of plastic materials, a field of view angle FOV_H (degrees), an edge thickness ET, an F number, and the like.

[0229] As shown in Figure 1 and Figure 2 , center thicknesses of the first lens 101 to the seventh lens 107 are denoted by CT1 to CT7, edge thicknesses at ends of effective regions of each lens are denoted by ET1 to ET7, center spacings between two adjacent lenses are denoted by CG1 to CG6, and edge spacings between edges of each lens are denoted by EG1 to EG6. Here, a center thickness of the cemented lens 145 is CT45, and an edge thickness is denoted by ET45.

[0230] Referring to Figure 2 , a back focal length (BFL) is an optical axis distance from the image sensor 700 to a center of the last lens. In Figure 1 , a TTL is an optical axis distance from a center of the first surface S1 of the first lens 101 to an upper surface of the image sensor 700.

[0231] As shown in Figure 3As shown, among the lenses of the lens unit 100 in the first embodiment, the lens surfaces of the first lens 101, the sixth lens 106, and the seventh lens 107 may include aspheric surfaces having a 30th-order aspheric surface coefficient. For example, the first lens 101, the sixth lens 106, and the seventh lens 107 may include lens surfaces having a 30th-order aspheric surface coefficient. As described above, since an aspheric surface having a 30th-order aspheric surface coefficient (a value other than "0") can significantly change the aspheric shape of the peripheral portion, the optical performance of the peripheral portion of the field of view (FOV) can be well corrected.

[0232] like Figure 4 As shown, the thicknesses T1 to T7 of the first to seventh lenses 101, 102, 103, 104, 105, 106, and 107 and the intervals 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 can be expressed at a pitch of 0.1 mm or 0.2 mm or more, and the pitch G1 to G6 between each lens can be expressed at a pitch of 0.1 mm or 0.2 mm or more.

[0233] When comparing the absolute values ​​of the radii of curvature of each lens, the sixth surface S6 of the third lens 103, along the optical axis OA, can have the largest radius of curvature among the lenses, and the tenth surface S10 of the fifth lens 105 can have the smallest radius of curvature among the lenses. The difference between the maximum and minimum radii of curvature can be 8 times or greater, for example, 9 to 11 times. The sensor-side surface of the glass lens positioned on the object side of the plastic lens can have the smallest radius of curvature among the lenses. The sensor-side surface of the fifth lens 105, positioned on the object side of the sixth lens 106, can have the smallest radius of curvature among the lenses.

[0234] Since the effective diameter of the plastic lens is smaller than that of the glass lens, the lens disposed on the object side of the plastic lens can have a strong refractive power to refract light passing through the plastic lens. In addition, the curvature radius of the lens surface can be smaller to enhance the refractive power.

[0235] Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 10 mm or less among the object side surface and the sensor side surface can be two or less. The absolute value of the radius of curvature of the sensor side surface (tenth surface) S10 of the fifth lens 105 and the sensor side surface (fourteenth surface) S14 of the seventh lens 107 can be 10 mm or less. Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 10 mm or more and 20 mm or less among the object side surface and the sensor side surface can be three or more and five or less. The absolute value of the radius of curvature of the object side surface (fifth surface) S5 of the third lens 103, the object side surface (seventh surface) S7 of the fourth lens 104, and the object side surface (eleventh surface) S11 of the sixth lens 106 can be 10 mm or more and 20 mm or less. Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 60 mm or more among the object side surface and the sensor side surface can be at least one and not more than four. The absolute value of the radius of curvature of the sensor side surface (sixth surface) S6 of the third lens 103 can be at least 60 mm.

[0236] In a temperature compensation design in which resolution needs to be maintained even when the temperature changes from -40 degrees to 100 degrees, a larger radius of curvature can be advantageous. In a design for temperature compensation, an aluminum lens barrel can be used as a lens barrel. The manufacturing tolerance of an aluminum lens barrel is large, so the misalignment of the optical axis of each lens is large when the lenses are assembled. Therefore, by designing a larger radius of curvature, the sensitivity to manufacturing tolerance can be reduced.

[0237] Reference Figure 6 The inclination angle of the lens surface can be expressed as a value in radians (rad) that is the slope of the lens surface at a point on the lens surface having a 0.1 pitch with respect to the Y-axis perpendicular to the optical axis, converted to a tangent value. When explaining the inclination angle of the lens surface, the cemented lens among the first to seventh lenses is excluded, and the inclination angle of the object side surface (first surface) S1 of the first lens 101 can be the smallest. Among the object side surfaces and the sensor side surfaces of the first to seventh lenses, the number of lenses having a value smaller than the absolute value of the inclination angle of the lens surface of the object side surface of the aspherical glass material can be five or less. Preferably, the number of lenses smaller than the absolute value of the inclination angle of the object side surface (first surface) S1 of the first lens 101 can be two. The absolute value of the inclination angle of the sensor side surface (sixth surface) S6 of the third lens 103 and the object side surface (thirteenth surface) S13 of the seventh lens 107 can be smaller than the absolute value of the inclination angle of the object side surface (first surface) S1 of the first lens 101.

[0238] The shape of the first lens 101 having an aspherical shape can be designed to be flat. If the aspherical surface is located at the most front in the optical system 1000, the performance of the lens is improved, but the assembly can be degraded. To improve the assembly, the shape of the first lens 101 should be designed to be flat. To minimize the influence on the lens disposed on the sensor side when the lens is assembled in the lens barrel, it can be designed to have almost no curvature.

[0239] With respect to the optical axis, when the center thickness of the lens is described, the center thickness CT3 of the third lens 103 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 largest center thickness and the smallest center thickness among the lenses can be in the range of 1.5 mm or more and 2.5 mm or less.

[0240] When explaining the center spacing CG between the lenses, the center spacing CG1 between the first lens 101 and the second lens 102 can be the largest, and the center spacing CG2 between the second lens 102 and the third lens 103 and the center spacing CG3 between the third lens 103 and the fourth lens 104 can be the smallest. Here, the smallest center spacing does not include the cemented surface of the cemented lens 145. The difference between the largest center spacing and the smallest center spacing among the spacings of the lenses spaced apart can be 5.5 mm or more, for example, in the range of 5.8 mm to 6.5 mm.

[0241] When explaining the effective diameter, the lens having the largest effective diameter can be disposed between the first lens 101 closest to the object and the seventh lens 107 closest to the image sensor 700. The lens having the largest effective diameter can be a glass lens. The lens having the largest effective diameter can be disposed between the first lens 101 and the cemented lens 145. The lens having the largest effective diameter can be the first lens 101. Here, the effective diameter is the average of the effective diameter of the object side surface and the effective diameter of the sensor side surface of each lens. The lens surface having the largest effective diameter can be the first surface S1 of the first lens 101.

[0242] The lens having the smallest effective diameter can be one of the cemented lenses or one of the plastic lenses, for example, the fifth lens 105 or the seventh lens 107 adjacent to the image sensor 700. For example, the effective diameter of the fifth lens 105 can be the smallest within the lens unit 100. The lens surface having the smallest effective diameter can be the tenth surface S10 of the fifth lens 105. The effective diameter of the plastic lens can be smaller than that of the glass lens. The plastic lens can be disposed adjacent to the image sensor.

[0243] An effective diameter of each of the first to fourth lenses 101 to 104 adjacent to the object side can be greater than effective diameters of the fifth to seventh lenses 105, 106, and 107 adjacent to the sensor side. The effective diameters of the first to fourth lenses 101 to 104 can be greater than a diagonal length of the image sensor 700. An average effective diameter of the seventh lens 107 can be less than the diagonal length of the image sensor 700. Accordingly, light incident through the plurality of lenses arranged along the optical axis can be guided to the image sensor 700.

[0244] When explaining the refractive index, the refractive index of the first lens 101 can be the greatest among the lenses, and can be greater than 1.8, for example, greater than 1.82. Either one or both of the third lens 103 and the sixth lens 106 can have the smallest refractive index among the lenses. For example, the refractive index of the sixth lens 106 can be the smallest among the lenses, and can be less than 1.6, for example, less than 1.55. The difference between the greatest refractive index and the smallest refractive index can be 0.2 or more. By providing a high refractive index lens made of glass closest to the object, and providing the lens adjacent to the image sensor 700 and the lens adjacent to the glass lens with a low refractive index made of plastic, the incidence efficiency can be increased, and the refractive power between the lenses made of glass and plastic can be adjusted to guide it to the image sensor 700.

[0245] When comparing the Abbe number, the Abbe number of the third lens 103 is the greatest among the lenses, and can be 70 or more. The Abbe number of the seventh lens 107 is the smallest among the lenses, and can be 25 or less. The difference between the greatest refractive index and the smallest Abbe number can be 50 or more. By making the Abbe number of the third lens 103 adjacent to the cemented lens 145 the greatest and making the Abbe number of the seventh lens 107 having a low refractive index adjacent to the image sensor 700 the smallest, the color dispersion of light traveling between the glass lenses can be controlled and the color dispersion between the glass and plastic lenses can be increased to guide it to the image sensor 700.

[0246] The focal lengths F1, F5, and F7 of the first lens 101, the fifth lens 105, and the seventh lens 107 can have a negative (-) sign. The first lens 101, the fifth lens 105, and the seventh lens 107 can 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 can have a positive (+) sign. The second lens 102, the third lens 103, the fourth lens 104, and the sixth lens 106 can have a positive (+) refractive power. The second lens 102, the third lens 103, and the fourth lens 104 having a positive (+) refractive power can be disposed on the sensor side of the first lens 101 having a negative (-) refractive power. Thereby, light incident on the object side can move away from the optical axis direction and then be gathered again in the optical axis direction, thereby forming a stable light path.

[0247] Further, the sixth lens 106 and the seventh lens 107, which are adjacently disposed lenses, can satisfy the following conditions.

[0248] Condition 1: refractive index of a lens having a positive refractive power < refractive index of a lens having a negative refractive power

[0249] Here, among the plastic lenses, the sixth lens 106 has a positive refractive power and the seventh lens 107 has a negative refractive power, such that according to the conditions 1 and 2, the refractive index of the sixth lens 106 is smaller than the refractive index of the seventh lens 107, and the dispersion value of the sixth lens 106 is greater than the dispersion value of the seventh lens 107. The chromatic aberration occurring in the plastic lenses can be corrected by the plastic lenses. Further, since the sixth lens 106 and the seventh lens 107, which are adjacently disposed plastic lenses, 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, the chromatic aberration occurring in the plastic lenses can be compensated by the plastic lenses.

[0250] An optical system has chromatic aberration, and the chromatic aberration is corrected by using a cemented lens or two lenses adjacently disposed in series. As the temperature changes from low to high, the lenses repeatedly shrink and expand. Since the lens characteristics of lenses of the same material change by the same amount according to the temperature change, the chromatic aberration between the lenses of the same material can be effectively corrected even if the temperature changes.

[0251] Therefore, in the first embodiment of the present application, the chromatic aberration occurring in the plastic lenses is corrected by using the cemented lens 145, the sixth lens 106, and the seventh lens 107.

[0252] The fourth lens 104 and the fifth lens 105, which are cemented lenses, can compensate for chromatic aberration occurring in a glass lens by satisfying 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. The refractive index difference is rounded to the third digit after the decimal point, and the Abbe number difference is rounded to the first digit after the decimal point for numerical comparison.

[0253] When the focal lengths are compared in absolute values, the focal length of the first lens 101 is the largest among the lenses, and can be 100 or more and 110 or less. Among the lenses, the first lens 101 made of glass can have the largest focal length and the smallest refractive power. The focal length of the fifth lens 105 is the smallest among the lenses, and the absolute value of the focal length of the fifth lens 105 can be 5 or more and 10 or less. Among the lenses, the fifth lens 105 made of glass can have the smallest focal length and the largest refractive power. Since a lens made of a plastic material having a small refractive power is disposed on the sensor side of the fifth lens 105, the refractive power of the fifth lens 105 can be increased.

[0254] Among the lenses other than the cemented lens 145, the lens having the smallest focal length can be the third lens 103. The difference between the largest focal length and the smallest focal length can be 50 or more or 80 or more. Accordingly, the optical system can have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. in a set view angle range, and can have good optical performance in an edge portion of the view angle.

[0255] The thickness T1 of the first lens 101 can be a difference of 1 times or more, for example, a difference of 1 to 1.2 times, between the largest thickness and the smallest thickness, and the central thickness CT1 can be the smallest and the edge thickness ET1 can be the largest. The thickness T2 of the second lens 102 can be the largest thickness in the range of 1 to 1.2 times the smallest thickness. The second lens 102 can have the largest central thickness CT2 and the smallest edge thickness ET2. The thickness T3 of the third lens 103 can be the largest at the center and the smallest at the edge, and the largest thickness can be in the range of 1.5 to 2 times the smallest thickness. The thickness T4 of the fourth lens 104 can be the largest at the center and the smallest at the edge, and the largest thickness can be in the range of 1.6 to 2.2 times the smallest thickness. The thickness T5 of the fifth lens 105 can be the smallest at the center and the largest at the edge, and the largest thickness can be in the range of 1.2 to 1.5 times the smallest thickness. The thickness T6 of the sixth lens 106 can be the largest at the center and the smallest at the edge, and the largest thickness can be in the range of 1 to 1.2 times the smallest thickness. The thickness T7 of the seventh lens 107 can be the smallest at the center and the largest at the edge, and the largest thickness can be in the range of 1 to 1.2 times the smallest thickness.

[0256] The center thickness CT45 of the cemented lens 145 can 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, while 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 cemented lens 145 has a maximum thickness at the center and a minimum thickness at the edges, and the maximum thickness can be in the range of 1 to 1.2 times the minimum thickness.

[0257] Among the distances G1 to G6 between the lenses, the first distance G1 between the first lens 101 and the second lens 102 may have a maximum value in the center portion and a minimum value in the edge portion. The second distance G2 between the second lens 102 and the third lens 103 may have a maximum value in the edge portion and a minimum value in the center portion. The third distance G3 between the third lens 103 and the fourth lens 104 may have a maximum value in the edge portion and a minimum value in the center portion. The fifth distance G5 between the fifth lens 105 and the sixth lens 106 may have a maximum value in the center portion and a minimum value in the edge portion. The sixth distance G6 between the sixth lens 106 and the seventh lens 107 may have a maximum value in the center portion and a minimum value in the edge portion.

[0258] like Figure 7 As shown, in Figure 1 In an optical system and camera module, the chief ray angle (CRA) at a field of view (FOV) of 1°, which is the end of the diagonal length of the image sensor, can be 10 degrees or greater, for example, within a range of 10 to 35 degrees or 10 to 25 degrees. Furthermore, the difference in the chief ray angle from a low temperature (-40 degrees) to a high temperature (95 degrees) can be 1 degree or less. Therefore, even if the temperature changes from low to high, the difference in the chief ray angle is minimal, achieving stable optical performance.

[0259] Figure 8 to Figure 10 It shows Figure 1 Graphs of diffraction modulation transfer functions (MTFs) at room temperature, low temperature, and high temperature in an optical system of FIG. 1 are graphs showing modulation according to spatial frequency. Figure 8 to Figure 10 As shown, in the first embodiment of the present invention, the deviation of the MTF at low or high temperature based on the room temperature can be less than 10%, that is, less than 7%.

[0260] Figure 11 to Figure 13 It shows Figure 1 The aberration characteristics of the optical system at room temperature, low temperature and high temperature are shown in the graph. Figure 11 to 13In the aberration diagram, from left to right, the spherical aberration (longitudinal spherical aberration), astigmatic field curves, and distortion are measured. In Figure 11 to Figure 13 In the aberration diagram, the X-axis can represent the focal length (mm) and the degree of distortion (%), and the Y-axis can represent the height of the image. Further, the graph for the spherical aberration is a graph for light in the wavelength band of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for the astigmatism and distortion aberration is a graph for light in the wavelength band of about 546 nm. In Figure 11 to Figure 13 In the aberration diagram, it can be explained that the closer each curve at room temperature, low temperature, and high temperature is to the Y-axis, the better the aberration correction function. It can be seen that the optical system 1000 according to the first embodiment has a measurement value close to the Y-axis in almost all regions. That is, the optical system 1000 according to the first embodiment has improved resolution, and can have good optical performance not only in the center of the field of view (FOV) but also in the edge portion. 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 11 to Figure 13 In the aberration diagram, it can be explained that the closer each curve at room temperature, low temperature, and high temperature is to the Y-axis, the better the aberration correction function. It can be seen that the optical system 1000 according to the first embodiment has a measurement value close to the Y-axis in almost all regions. That is, the optical system 1000 according to the first embodiment has improved resolution, and can have good optical performance not only in the center of the field of view (FOV) but also in the edge portion. 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

[0261] Table 3 compares the changes in the optical characteristics (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, and it can be seen that the change rate of the optical characteristics at low temperature is 5% or less (for example, 3% or less) relative to room temperature, and it can be seen that the change rate of the optical characteristics at low temperature is 5% or less (for example, 3% or less) relative to room temperature.

[0262] [Table 3]

[0263] Room temperature Low temperature High temperature Low temperature / room temperature High temperature / room temperature EFL(F) 14.9017 14.8493 14.9652 99.65％ 100.43％ BFL 0.0369 0.0394 0.0348 106.78％ 94.31％ F# 1.6117 1.6060 1.6186 99.65％ 100.43％ TTL 27.8600 27.8217 27.9051 99.86％ 100.16％ FOV 30.0000 30.1166 29.8633 100.39％ 99.54％

[0264] Therefore, as shown in Table 3, it can be seen that the change in the optical characteristics (for example, the change rate of the effective focal length (EFL), TTL, BFL, F number, and field of view (FOV)) is 10% or less, i.e., 5% or less, for example, in the range of 0 to 5%, with a change in temperature from low temperature to high temperature. This makes it possible to design temperature compensation for plastic lenses even in the case of using at least one or two or more plastic lenses, thereby preventing a decrease in reliability of the optical characteristics.

[0265] 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).

[0266] An optical system according to a second embodiment of the present invention will be described.

[0267] Figure 14 is a side sectional view of an optical system and a camera module having the same according to a second embodiment; Figure 15 Is used to explain the Figure 14 A side sectional view showing the relationship between the n-th lens and the (n-1)-th lens; Figure 16 It shows Figure 14 Table of aspheric coefficients of lenses in optical systems; Figure 17 It shows Figure 14 A table showing the thickness of each lens and the spacing between adjacent lenses in the optical system; Figure 18 It shows Figure 14 a table of sag values ​​of lens surfaces of first to seventh lenses in the optical system; Figure 19 It shows Figure 14 a table of inclination angle values ​​of lens surfaces of first to seventh lenses in the optical system; Figure 20 It shows that according to Figure 14 The position of the image sensor in the optical system, and the table of chief ray angle (CRA) data at room temperature, low temperature and high temperature; Figure 21 to Figure 22 Is to show about Figure 14 a graph of diffraction modulation transfer function (MTF) data of an optical system at room temperature, low temperature, and high temperature; and Figure 23 to Figure 25 Is to show about Figure 14 A graph showing the aberration characteristics of an optical system at room temperature, low temperature, and high temperature.

[0268] refer to Figure 14 and Figure 15 The optical system 1100 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 arranged along the optical axis OA of the optical system 1100. Light corresponding to object information may pass through the first to seventh lenses 201 to 207 and the optical filter 900 and be incident on the image sensor 700.

[0269] The first lens 201 can be disposed closest to the object side. The first lens 201 can be disposed farthest from the sensor side. The first lens 201 can have a negative (-) refractive power on the optical axis OA. The first lens 201 can include a plastic material or a glass material, and can be, for example, a glass material. The first lens 201 made of a glass material can reduce changes in a center position and a radius of curvature due to temperature changes according to a surrounding environment, and can protect an incident side surface of the optical system 1100.

[0270] The first surface S1 on the object side of the first lens 201 can be convex, and the second surface S2 on the sensor side can be concave with respect to the optical axis. The first lens 201 can have a meniscus shape convex toward the object side. The first lens 201 is made of glass and can have an aspherical surface. Aspherical coefficients of the first surface S1 and the second surface S2 can be provided as L1S1, L1S2 of the first lens 201. Figure 3 The first lens 201 can be manufactured as a lens having an aspherical surface by injection molding of a glass 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 within a mold having an aspherical shape and by a heating and compression process.

[0271] The first lens 201 is provided by an aspherical glass material such that a glass material having a high transmittance and a refractive index has an aspherical surface, which can reduce the number of lenses in the optical system. When the temperature becomes a low temperature or a high temperature, the aspherical glass material can maintain optical performance at a constant level due to the glass material. In addition, since the aspherical surface is applied to the glass material, the refractive index of light does not significantly change even if the lens is designed to be thin. Therefore, unlike the optical system in which the first lens is designed to be thickest in a horizontal viewing angle in the range of 30 to 50 degrees, the optical system of the present application can provide a thin first lens made of an aspherical glass material. Here, the thickness of the lens can include a center thickness and an edge thickness.

[0272] Further, the second lens 202 can be spaced apart further from the first lens 201 due to the refractive property of the first lens 201. That is, the center spacing between the first lens 201 and the second lens 202 can be the largest within the lens unit. Also, that is, the edge spacing between the first lens 201 and the second lens 202 can be the largest within the lens unit. The first surface S1 of the first lens 201 can have a critical point from the optical axis OA to the end of the effective region. When the first surface S1 has the critical point, it can be located within a range of 70% to 80% of the effective radius r11 from the optical axis OA, preferably within a range of 74% to 78% of the effective radius r11 from the optical axis OA. The critical point of the first surface S1 can be located within a range of 5 mm to 5.3 mm from the optical axis OA, preferably within a range of 5 mm to 5.1 mm from the optical axis OA.

[0273] The refractive index n1 of the first lens 201 can satisfy a condition of n1>1.8 or n1>1.82. Since the refractive index n1 of the first lens 201 is the largest in the lens unit 200, the curvature radius of the first lens 201 and the second lens 202 can be increased, and lens manufacturing can be easy. When 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 power of the first lens 101 and the second lens 102. In this case, lens manufacturing is not easy, the lens defect rate increases, and can cause a reduction in yield.

[0274] The second lens 202 can be disposed as the second from the object side. The second lens 202 can be disposed as the sixth from the sensor side. The second lens 202 can be disposed between the first lens 201 and the third lens 203. The second lens 202 can have a positive (+) refractive power on the optical axis OA. The second lens 202 can include a plastic or a glass material. For example, the second lens 202 can be provided by a glass material.

[0275] The object side third surface S3 of the second lens 202 can be convex and the sensor side fourth surface S4 can be convex with respect to the optical axis OA. The second lens 202 can have a shape in which both surfaces are convex. The second lens 202 is made of glass and can be spherical. At least one or both of the third surface S3 and the fourth surface S4 can be spherical.

[0276] Since the two surfaces of the second lens 202 are convexly disposed, the number of lenses and the TTL of the optical system can be minimized, and light can be effectively refracted. Further, when the radius of curvature of the third surface S3 of the second lens 202 is L2R1 and the radius of curvature of the fourth surface S4 is L2R2, the condition of L2R1 < |L2R2| can be satisfied. Thereby, light can be effectively refracted by the third surface S3 so that the effective diameter of the third lens 203 to the seventh lens 207 can be guided so as not to increase, and the TTL can be reduced. When L2R1 > |L2R2|, many aberrations can occur on the object side surface of the second lens 202, the refractive efficiency of light at the sensor side surface can be reduced, the effective diameter of the rear lens can increase, and the TTL can also become larger.

[0277] An aperture stop can be disposed around the sensor side fourth surface S4 of the second lens 202. The aperture can reduce the TTL in the field of view range, and can miniaturize the optical system. Therefore, a reduction in yield due to the weight of the optical system can be prevented, and production efficiency can be improved. Further, by reducing the TTL in the horizontal field of view (FOV_H) of 25 degrees to 36 degrees, the optical system can be miniaturized.

[0278] The third lens 203 can be disposed as the third from the object side. The third lens 203 can be disposed as the fifth from the sensor side. The third lens 203 can be disposed between the second lens 102 and the fourth lens 204. The third lens 203 can have a positive (+) refractive power on the optical axis OA. The third lens 203 can include a plastic or a glass material. For example, the third lens 203 can be provided by a glass material.

[0279] The object side fifth surface S5 of the third lens 203 can be convex, and the sensor side sixth surface S6 can be concave with respect to the optical axis. The third lens 203 can have a meniscus shape convex on the object side on the optical axis OA. The third lens 203 is made of glass and can be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 can be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0280] The fourth lens 204 can be disposed as the fourth from the object side. The fourth lens 204 can be disposed as the fourth from the sensor side. The fourth lens 204 can be disposed between the third lens 203 and the fifth lens 205. The fourth lens 204 can have a positive (+) or negative (-) refractive power on the optical axis OA. The fourth lens 204 can have a positive (+) refractive power. The fourth lens 204 can have a positive (+) refractive power different from that of the fifth lens 205. The fourth lens 204 can include a plastic or a glass material. For example, the fourth lens 204 can be provided by a glass material. The fourth lens 204 can be provided by the same material as the fifth lens 205.

[0281] The seventh surface S7 of the fourth lens 204 on the object side can be convex, and the eighth surface S8 on the sensor side can be concave with respect to the optical axis. The fourth lens 204 can have a meniscus shape convex toward the object side. The fourth lens 204 is made of glass and can have a spherical surface. At least one or both of the seventh surface S7 and the eighth surface S8 can be spherical. The seventh surface S7 and the eighth surface S8 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0282] The fifth lens 205 can be disposed as the fifth from the object side. The fifth lens 205 can be disposed as the third from the sensor side. The fifth lens 205 can be disposed between the fourth lens 204 and the sixth lens 206. The fifth lens 205 can have a positive (+) or negative (-) refractive power on the optical axis OA. The fifth lens 205 can have a negative (-) refractive power. The fifth lens 205 can have a negative (-) refractive power different from that of the fourth lens 204. The fifth lens 205 can include a plastic or a glass material. For example, the fifth lens 205 can be provided by a glass material. The fifth lens 205 can be provided by the same material as the fourth lens 204.

[0283] The ninth surface S9 of the fifth lens 205 on the object side can be convex, and the tenth surface S10 on the sensor side can be concave with respect to the optical axis. The fifth lens 205 can have a meniscus shape convex toward the object side from the optical axis OA. The fifth lens 205 is made of glass and can have a spherical surface. At least one of the ninth surface S9 and the tenth surface S10 can be a spherical surface. At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 205 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0284] The fourth lens 204 and the fifth lens 205 can be cemented. A bonding surface between the fourth lens 204 and the fifth lens 205 can be defined as an eighth surface S8. The eighth surface S8 can be the same surface as a ninth surface S9 of the fifth lens 205. An object side surface of the cemented lens 245 can be convex, and a sensor side surface can be concave. A spacing between the fourth lens 204 and the fifth lens 205 can be less than 0.01 mm, and can be attached with an adhesive. The spacing between the fourth lens 204 and the fifth lens 205 can be less than 0.01 mm from the optical axis OA to the end of the effective area. The fourth lens 204 and the fifth lens 205 can have opposite refractive powers. The composite refractive power of the fourth lens 204 and the fifth lens 205 can have a negative (-) refractive power.

[0285] A value of the radius of curvature of the cemented surface S8 of the cemented lens 245 can be less than 50. For example, the value of the radius of curvature of the cemented surface S8 of the cemented lens 245 can be less than 40. The cemented surface S8 of the cemented lens 245 can be formed in a gentle shape. Thereby, the cementing process of the fourth lens 204 and the fifth lens 205 forming the cemented lens 245 is advantageous, and the cementing retention strength can be increased.

[0286] A product of the refractive power of the object side fourth lens 204 and the refractive power of the sensor side fifth lens 205 of the cemented lens 245 can be less than 0. A product of the focal length of the object side fourth lens 205 and the focal length of the sensor side fifth lens 205 of the cemented lens 245 can be less than 0. Accordingly, 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 in the aberration.

[0287] The composite refractive power of the cemented lens 245 has a negative (-) refractive power, and can have a negative (-) refractive power with respect to the third lens 203 on the object side and the sixth lens 206 on the sensor side of the cemented lens 245. Accordingly, the fourth lens 204, the cemented lens 245, and the fifth lens 205 can refract a portion of the incident light in the optical axis direction.

[0288] An effective diameter of the fourth lens 204 can be greater than a diagonal length of the image sensor 700. The effective diameter of the fourth lens 204 is an average of the effective diameters of the seventh surface S7 and the eighth surface S8, and can be greater than the diagonal length of the image sensor 700. An effective diameter of the fifth lens 205 can be less than the effective diameter of the fourth lens 204 and greater than the diagonal length of the image sensor 700. An effective diameter of the seventh surface S7 of the fourth lens 204 can be greater than the diagonal length of the image sensor 700, and an effective diameter of the tenth surface S10 of the fifth lens 205 can be less than the diagonal length of the image sensor 700.

[0289] When the fifth lens 205 is a spherical lens and the seventh lens 207 is an aspherical lens, a difference in effective diameter between the object side ninth surface S9 of the fifth lens 205 and the sensor side tenth surface S10 can be set to be the largest. For example, when the effective diameters of the ninth surface S9 and the sensor side tenth surface S10 of the fifth lens 205 are CA51 and CA52, a condition of CA51 > CA52 is satisfied, and a difference between CA51 and CA52 can be the largest among the differences in effective diameter between the object side surface and the sensor side surface of each lens. Accordingly, the difference in effective diameter between the object side surface and the sensor side surface of the fifth lens 205 can be set to be maximized in order to effectively guide light to travel through the aspherical lens having a relatively small effective diameter. Accordingly, a more slim optical system can be provided. The effective diameter of the fifth lens 105 can satisfy a condition of 1.1 < CA51 / CA52 < 1.5.

[0290] The cemented lens 245 is cemented with a glass lens having a different refractive index, has a spherical refractive surface, and at least one lens disposed closer to the sensor than the cemented lens 245 is an aspherical lens, so that spherical aberration can be compensated. In addition, at least one lens among the lenses disposed closer to the sensor than the cemented lens 245 is an aspherical lens and is disposed to have a small effective diameter, so that light can be effectively guided to travel through the aspherical lens to the image sensor 700. Since the cemented lens 245 is disposed between the aspherical lenses and between the spherical lenses, chromatic aberration correction can be more effective. By positioning the cemented lens 245 within the optical system, the TTL can be reduced.

[0291] The sixth lens 206 can be disposed as the sixth lens from the object side. The sixth lens 206 can be disposed as the second lens from the sensor side. The sixth lens 206 can be disposed between the fifth lens 205 and the seventh lens 207. The sixth lens 206 can have a positive (+) or negative (-) refractive power on the optical axis OA. The sixth lens 206 can have a positive (+) refractive power. The sixth lens 206 can include a plastic or a glass material. For example, the sixth lens 206 can be provided by a plastic material.

[0292] The sixth lens 206 can have a convex shape on the object side eleventh surface S11 and a convex shape on the sensor side twelfth surface S12 with respect to the optical axis. The sixth lens 206 can have a convex shape on both surfaces along the optical axis OA. At least one or both of the eleventh surface S11 and the twelfth surface S12 can be aspherical. Aspherical coefficients of the eleventh surface S11 and the twelfth surface S12 can be provided as L1 and L2 of L6 of Figure 15 .

[0293] The eleventh surface S11 of the sixth lens 206 can be configured to have no critical point from the optical axis OA to the end of the effective region. The twelfth surface S12 can be configured to have at least one critical point from the optical axis OA to the end of the effective region.

[0294] The seventh lens 207 can be configured to be closest to the sensor side. The seventh lens 207 can be configured to be farthest from the object side. The seventh lens 207 can have a positive (+) or negative (-) refractive power on the optical axis OA. The seventh lens 207 can have a negative (-) refractive power. The seventh lens 207 can include a plastic or glass material. For example, the seventh lens 207 can be made of a plastic material.

[0295] On the optical axis, the object-side thirteenth surface S13 of the seventh lens 207 can be convex, and the sensor-side fourteenth surface S14 can be concave. The seventh lens 207 can have a meniscus shape convex toward the object side. At least one of the thirteenth surface S13 and the fourteenth surface S14 can be an aspheric surface. For example, both the thirteenth surface S13 and the fourteenth surface S14 can be aspheric. The aspheric coefficients of the thirteenth surface S13 and the fourteenth surface S14 can be provided as S1 and S2 of L7 in Equation 1. Figure 15

[0296] The thirteenth surface S13 of the seventh lens 207 can have a critical point from the optical axis OA to the end of the effective region. When the thirteenth surface S13 has a critical point, it can be located in a range of 40% to 50% of the effective radius r71 from the optical axis OA, preferably in a range of 43% to 47% of the effective radius r71 from the optical axis OA. The critical point of the thirteenth surface S13 can be located in a range of 1.5 mm to 2.0 mm from the optical axis OA, preferably in a range of 1.8 mm to 1.9 mm from the optical axis OA. The thirteenth surface S13 having such a critical point can refract incident light to the center portion and the edge portion, and improve aberration.

[0297] The fourteenth surface S14 of the seventh lens 207 can have a critical point from the optical axis OA to the end of the effective region. When the fourteenth surface S14 has a critical point, it can be located in a range of 60% to 70% of the effective radius r72 from the optical axis OA, preferably in a range of 64% to 67% of the effective radius r72 from the optical axis OA. The critical point of the fourteenth surface S14 can be located in a range of 2.5 mm to 3.1 mm from the optical axis OA, preferably in a range of 2.9 mm to 3.0 mm from the optical axis OA.

[0298] ​The critical point of the thirteenth surface S13 and the fourteenth surface S14 is a point at which the sign of the slope value with respect to the optical axis OA and a direction perpendicular to the optical axis OA changes from positive (+) to negative (-) or from negative (-) to positive (+), and can represent a point at which the slope value is 0. Also, the critical point of the thirteenth surface S13 and the fourteenth surface S14 can be a point at which the slope value of the tangent line passing through the lens surface first increases and then decreases, or first decreases and then increases.

[0299] The seventh lens 207 can be a plastic lens closest to the image sensor 700. Also, by arranging two or more plastic lenses adjacent to the image sensor 700, aberrations such as spherical aberration and chromatic aberration can be improved by the lens surface having an aspherical surface, and the influence on resolution can be controlled. Also, by arranging a plastic lens as a lens adjacent to the image sensor 700, the plastic lens can be less sensitive to assembly tolerance than a glass lens. In other words, being less sensitive to assembly tolerance means that even if assembly is performed slightly differently than the design during assembly, the optical performance can not be significantly affected. Also, by providing two lenses 206 and 207 adjacent to the image sensor 700 with plastic, the optical performance can be improved by the lens surface having an aspherical surface, and for example, aberration characteristics can be improved and degradation of resolution can be prevented.

[0300] The sixth lens 206 and the seventh lens 207 are disposed to be spaced apart from each other, but can include the characteristics of a cemented lens. The sixth lens 206 and the seventh lens 207 can have opposite refractive powers. The product of the refractive power of the sixth lens 206 and the refractive power of the seventh lens 207 can be less than 0. The product of the focal length of the sixth lens 206 and the focal length of the seventh lens 207 can be less than 0. Accordingly, the aberration characteristics of the optical system can be improved. If the signs of the refractive powers of the two lenses having the characteristics of a cemented lens are the same, there is a limit to the improvement in aberration.

[0301] The sixth lens 206 and the seventh lens 207 can be made of the same material. The sixth lens 206 and the seventh lens 207 can be made of a plastic material. The sixth lens 206 and the seventh lens 207 can be made of the same material as the cemented lens 245.

[0302] [Table 4]

[0303]

[0304]

[0305] Table 4 shows surface numbers (surfaces), radii of curvature (radius), center thicknesses of each lens or distances between lens surfaces (thickness), refractive indices (nd), Abbe numbers (vd), effective radii (half aperture), and focal lengths (focal length) of the lenses according to the first embodiment of the present application. At this time, units of the radii of curvature and the thicknesses or distances can be mm.

[0306] [Table 5]

[0307]

[0308]

[0309] Table 5 shows categories of the above mathematical expressions in the optical system 1100 of the embodiment, including a total top length (TTL) (mm) of the optical system 1100, a back focal length (BFL), an effective focal length F (mm), ImgH (mm), an effective diameter CA (mm), a thickness (mm), a TTL (mm), TD (mm) which is an optical axis distance from the first surface S1 to the fourteenth surface S14, composite focal lengths F2_7, F3_7, F4_7, F5_7, F6_7, and F4_5 (mm) of the first lens to the seventh lens, a sum of refractive indices, a sum of Abbe numbers, a sum of thicknesses (mm), a sum of spacings between adjacent lenses, an effective diameter characteristic, a sum of refractive indices of glass lenses, a sum of refractive indices of plastic materials, a field of view angle FOV_H (degree), an edge thickness ET, an F number, and the like.

[0310] As shown in Figure 14 and Figure 15 , center thicknesses of the first lens 201 to the seventh lens 207 are denoted by CT1 to CT7, edge thicknesses at ends of effective regions of each lens are denoted by ET1 to ET7, center spacings between two adjacent lenses are denoted by CG1 to CG6, and edge spacings between edges of each lens are denoted by EG1 to EG6. Here, the center thickness of the cemented lens 245 is CT45, and the edge thickness is denoted by ET45.

[0311] Referring to Figure 15 , the back focal length (BFL) is an optical axis distance from the image sensor 700 to the center of the last lens. In Figure 14 , the 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 700.

[0312] As shown in Figure 16As illustrated in the lens of the lens unit 200 in the first embodiment, the lens surfaces of the first lens 201, the sixth lens 206, and the seventh lens 207 can include an aspherical surface having a 30th order aspherical surface coefficient. For example, the first lens 201, the sixth lens 206, and the seventh lens 207 can include a lens surface having a 30th order aspherical surface coefficient. As described above, since the aspherical surface having a 30th order aspherical coefficient (a value other than "0") can significantly change the aspherical shape of the edge portion, the optical performance of the edge portion of the field of view (FOV) can be well corrected.

[0313] As Figure 17 illustrated, the thicknesses T1 to T7 of the first to seventh lenses 201, 202, 203, 204, 205, 206, and 207 and the intervals G1 to G6 between the adjacent two lenses can be set. As Figure 16 illustrated, the thicknesses T1 to T7 of each lens in the Y-axis direction can be expressed in an interval of 0.1 mm or more or 0.2 mm or more, and the intervals G1 to G6 between each lens can be expressed in an interval of 0.1 mm or more or 0.2 mm or more.

[0314] When comparing the absolute values of the radii of curvature of each lens, the radius of curvature of the sixth surface S6 of the third lens 203 on the optical axis OA can be the largest among the lenses, and the radius of curvature of the tenth surface S10 of the fifth lens 205 can be the smallest among the lenses. The difference between the largest radius of curvature and the smallest radius of curvature can be 8 times or more, for example, 9 to 11 times. The radius of curvature of the sensor side surface of the glass material lens disposed on the object side of the plastic material lens can be the smallest among the lenses. The radius of curvature of the sensor side surface of the fifth lens 205 disposed on the object side of the sixth lens 206 can be the smallest among the lenses.

[0315] Since the effective diameter of the plastic lens is smaller than the effective diameter of the glass lens, the lens disposed on the object side of the plastic lens can have a strong refractive power to refract the light passing through the plastic lens. In addition, the radius of curvature of the lens surface can be small to enhance the refractive power.

[0316] Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 10 mm or less among the object side surface and the sensor side surface can be two or less. The absolute value of the radius of curvature of the sensor side surface (the tenth surface) S10 of the fifth lens 205 and the sensor side surface (the fourteenth surface) S14 of the seventh lens 207 can be 10 mm or less. Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 10 mm or more and 20 mm or less among the object side surface and the sensor side surface can be three or more and five or less. The absolute value of the radius of curvature of the object side surface (the fifth surface) S5 of the third lens 203, the object side surface (the seventh surface) S7 of the fourth lens 204, and the object side surface (the eleventh surface) S11 of the sixth lens 206 can be 10 mm or more and 20 mm or less. Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 60 mm or more among the object side surface and the sensor side surface can be at least one and not more than four. The absolute value of the radius of curvature of the sensor side surface (the fourth surface) S4 of the second lens 202, the sensor side surface (the sixth surface) S6 of the third lens 203, and the sensor side surface (the twelfth surface) S12 of the sixth lens 206 can be at least 60 mm.

[0317] In a temperature compensation design in which resolution needs to be maintained even when the temperature changes from -40 degrees to 100 degrees, a larger radius of curvature can be advantageous. In a design for temperature compensation, an aluminum lens barrel can be used as a lens barrel. The manufacturing tolerance of the aluminum lens barrel is large, so the misalignment of the optical axis of each lens is large when the lens is assembled. Therefore, by designing a larger radius of curvature, the sensitivity to the manufacturing tolerance can be reduced.

[0318] Reference Figure 19 The inclination angle of the lens surface can be expressed as a value in radians, which is the slope of the lens surface at a point on the lens surface having a 0.1 pitch with respect to the Y-axis perpendicular to the optical axis, converted to a tangent value. When explaining the inclination angle of the lens surface, the cemented lens among the first to seventh lenses is not included, and the inclination angle of the object side surface (the first surface) S1 of the first lens 101 can be the smallest. Among the object side surfaces and the sensor side surfaces of the first to seventh lenses, the number of lenses having a value smaller than the absolute value of the inclination angle of the lens surface of the object side surface of the aspherical glass material can be five or less. Preferably, the lens smaller than the absolute value of the inclination angle of the object side surface (the first surface) S1 of the first lens 201 can be one. The absolute value of the inclination angle of the sensor side surface (the sixth surface) S6 of the third lens 203 can be smaller than the absolute value of the inclination angle of the object side surface (the first surface) S1 of the first lens 201.

[0319] The shape of the first lens 201 having an aspherical shape can be designed to be flat. If the aspherical surface is located at the most front in the optical system 1100, the performance of the lens is improved, but the assembly property can be lowered. To improve the assembly property, the shape of the first lens 201 should be designed to be flat. To minimize the influence on the lens disposed on the sensor side when the lens is assembled in the lens barrel, it can be designed to have almost no curvature.

[0320] With respect to the optical axis, when the center thickness of the lens is described, the center thickness CT3 of the third lens 203 is the largest among the lenses, and the center thickness CT7 of the seventh lens 207 is the smallest among the lenses. The difference between the largest center thickness and the smallest center thickness among the lenses can be in the range of 1.5 mm or more and 2.5 mm or less.

[0321] When explaining the center spacing CG between the lenses, the center spacing CG1 between the first lens 201 and the second lens 202 can be the largest, and the center spacing CG2 between the second lens 202 and the third lens 203 and the center spacing CG3 between the third lens 203 and the fourth lens 204 can be the smallest. Here, the smallest center spacing does not include the cemented surface of the cemented lens 245. The difference between the largest center spacing and the smallest center spacing among the spacings of the lenses spaced apart can be 5.5 mm or more, for example, in the range of 5.8 mm to 6.5 mm.

[0322] When explaining the effective diameter, the lens having the largest effective diameter can be disposed between the first lens 201 closest to the object and the seventh lens 207 closest to the image sensor 700. The lens having the largest effective diameter can be a glass lens. The lens having the largest effective diameter can be disposed between the first lens 201 and the cemented lens 245. The lens having the largest effective diameter can be the first lens 201. Here, the effective diameter is the average of the effective diameter of the object side surface and the effective diameter of the sensor side surface of each lens. The lens surface having the largest effective diameter can be the first surface S1 of the first lens 201.

[0323] The lens having the smallest effective diameter can be one of the cemented lenses or one of the plastic lenses, for example, the fifth lens 205 or the seventh lens 207 adjacent to the image sensor 700. For example, the effective diameter of the fifth lens 205 can be the smallest within the lens unit 200. The lens surface having the smallest effective diameter can be the tenth surface S10 of the fifth lens 205.

[0324] An effective diameter of each of the first to fourth lenses 201 to 204 adjacent to the object side can be greater than effective diameters of the fifth to seventh lenses 205, 206, and 207 adjacent to the sensor side. The effective diameters of the first to fourth lenses 201 to 204 can be greater than a diagonal length of the image sensor 700. An average effective diameter of the seventh lens 207 can be less than the diagonal length of the image sensor 700. Accordingly, light incident through the plurality of lenses arranged along the optical axis can be guided to the image sensor 700.

[0325] When the refractive indices are explained, the refractive index of the first lens 201 can be the greatest among the lenses, and can be greater than 1.8, for example, greater than 1.82. Either one or both of the third lens 203 and the sixth lens 206 can have the smallest refractive index among the lenses. For example, the refractive index of the sixth lens 206 can be the smallest among the lenses, and can be less than 1.6, for example, less than 1.55. The difference between the greatest refractive index and the smallest refractive index can be 0.2 or more. By providing a high refractive index lens made of glass closest to the object, and providing the lens adjacent to the image sensor 700 and the lens adjacent to the glass lens with a low refractive index made of plastic, the incidence efficiency can be increased, and the refractive power between the lenses made of glass and plastic can be adjusted to guide it to the image sensor 700.

[0326] When the Abbe numbers are compared, the Abbe number of the third lens 203 is the greatest among the lenses, and can be 70 or more. The Abbe number of the seventh lens 207 is the smallest among the lenses, and can be 25 or less. The difference between the greatest refractive index and the smallest Abbe number can be 50 or more. By making the Abbe number of the third lens 203 adjacent to the cemented lens 245 the greatest and making the Abbe number of the seventh lens 207 having a low refractive index adjacent to the image sensor 700 the smallest, 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 it to the image sensor 700.

[0327] Focal lengths F1, F5, and F7 of the first lens 201, the fifth lens 205, and the seventh lens 207 can have a negative (-) sign. The first lens 201, the fifth lens 205, and the seventh lens 207 can have a negative (-) refractive power. Focal lengths F2, F3, F4, and F6 of the second lens 202, the third lens 203, the fourth lens 204, and the sixth lens 206 can have a positive (+) sign. The second lens 202, the third lens 203, the fourth lens 204, and the sixth lens 206 can have a positive (+) refractive power. The second lens 202, the third lens 203, the fourth lens 204, and the sixth lens 206 having a positive (+) refractive power can be disposed on the sensor side of the first lens 201 having a negative (-) refractive power. Thereby, light incident on the object side can move away from the optical axis direction and then be gathered again in the optical axis direction, thereby forming a stable light path.

[0328] Further, the sixth lens 206 and the seventh lens 207, which are adjacently disposed lenses, can satisfy the following conditions.

[0329] Condition 1: Refractive index of a lens having a positive refractive power < Refractive index of a lens having a negative refractive power

[0330] Condition 2: Dispersion of a lens having a positive refractive power > Dispersion of a lens having a negative refractive power

[0331] Here, among the plastic lenses, the sixth lens 206 has a positive refractive power and the seventh lens 207 has a negative refractive power, such that according to the conditions 1 and 2, the refractive index of the sixth lens 206 is less than the refractive index of the seventh lens 207, and the dispersion value of the sixth lens 206 is greater than the dispersion value of the seventh lens 207. The chromatic aberration occurring in the plastic lenses can be corrected by the plastic lenses. Further, since the sixth lens 206 and the seventh lens 207, which are adjacently disposed plastic lenses, 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, the chromatic aberration occurring in the plastic lenses can be compensated for by the plastic lenses.

[0332] An optical system has chromatic aberration, and the chromatic aberration is corrected by using a cemented lens or two lenses adjacently disposed. As the temperature changes from low to high, the lenses repeatedly contract and expand. Since the lens characteristics of lenses of the same material change by the same amount according to the temperature change, the chromatic aberration between the lenses of the same material can be effectively corrected even if the temperature changes.

[0333] Therefore, in the second embodiment of the present application, the chromatic aberration occurring in the plastic lenses is corrected by using the cemented lens 245, the sixth lens 206, and the seventh lens 207.

[0334] The fourth lens 204 and the fifth lens 205, which are cemented lenses, can compensate for chromatic aberration occurring in a glass lens by satisfying 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. The refractive index difference is rounded to the third digit after the decimal point, and the Abbe number difference is rounded to the first digit after the decimal point for numerical comparison.

[0335] When the focal lengths are compared in absolute values, the focal length of the first lens 201 is the largest among the lenses, and can be 120 or more and 150 or less. Among the lenses, the first lens 201 made of glass can have the largest focal length and the smallest refractive power. 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 can be 5 or more and 20 or less. Among the lenses, the fifth lens 205 made of glass can have the smallest focal length and the largest refractive power. Since a lens made of a plastic material having a small refractive power is disposed on the sensor side of the fifth lens 205, the refractive power of the fifth lens 205 can be increased.

[0336] Among the lenses other than the cemented lens 245, the lens having the smallest focal length can be the third lens 203. The difference between the largest focal length and the smallest focal length can be 50 or more or 80 or more. Accordingly, the optical system can have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. in a set field of view, and can have good optical performance in an edge portion of the field of view.

[0337] The thickness T1 of the first lens 201 can be a difference of 1 times or more, for example, a difference of 1 to 1.2 times, between the largest thickness and the smallest thickness, and the central thickness CT1 can be the smallest and the edge thickness ET1 can be the largest. The thickness T2 of the second lens 202 can be the largest thickness in the range of 1 to 1.2 times the smallest thickness. The second lens 202 can have the largest central thickness CT2 and the smallest edge thickness ET2. The thickness T3 of the third lens 203 can be the largest at the center and the smallest at the edge, and the largest thickness can be in the range of 1.5 to 2 times the smallest thickness. The thickness T4 of the fourth lens 204 can be the largest at the center and the smallest at the edge, and the largest thickness can be in the range of 1.6 to 2.2 times the smallest thickness. The thickness T5 of the fifth lens 205 can be the smallest at the center and the largest at the edge, and the largest thickness can be in the range of 1.2 to 1.5 times the smallest thickness. The thickness T6 of the sixth lens 206 can be the largest at the center and the smallest at the edge, and the largest thickness can be in the range of 1 to 1.2 times the smallest thickness. The thickness T7 of the seventh lens 207 can be the smallest at the center and the largest at the edge, and the largest thickness can be in the range of 1 to 1.2 times the smallest thickness.

[0338] The center thickness CT45 of the cemented lens 245 can 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, while 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 cemented lens 245 has a maximum thickness at the center and a minimum thickness at the edges, and the maximum thickness can be in the range of 1 to 1.2 times the minimum thickness.

[0339] Among the distances G1 to G6 between the lenses, the first distance G1 between the first lens 201 and the second lens 202 may have a maximum value in the center portion and a minimum value in the edge portion. The second distance G2 between the second lens 202 and the third lens 203 may have a maximum value in the edge portion and a minimum value in the center portion. The third distance G3 between the third lens 203 and the fourth lens 204 may have a maximum value in the edge portion and a minimum value in the center portion. The fifth distance G5 between the fifth lens 205 and the sixth lens 206 may have a maximum value in the center portion and a minimum value in the edge portion. The sixth distance G6 between the sixth lens 206 and the seventh lens 207 may have a maximum value in the center portion and a minimum value in the edge portion.

[0340] like Figure 20 As shown, in Figure 14 In an optical system and camera module, the chief ray angle (CRA) at a field of view (FOV) of 1°, which is the end of the diagonal length of the image sensor, can be 10 degrees or greater, for example, within a range of 10 to 35 degrees or 10 to 25 degrees. Furthermore, the difference in the chief ray angle from a low temperature (-40 degrees) to a high temperature (95 degrees) can be 1 degree or less. Therefore, even if the temperature changes from low to high, the difference in the chief ray angle is minimal, achieving stable optical performance.

[0341] Figure 21 to Figure 23 It shows Figure 14 Graphs of diffraction modulation transfer functions (MTFs) at room temperature, low temperature, and high temperature in an optical system of FIG. 1 are graphs showing modulation according to spatial frequency. Figure 21 to Figure 23 As shown, in the second embodiment of the present invention, the deviation of the MTF at low or high temperature based on the room temperature can be less than 10%, that is, less than 7%.

[0342] Figure 24 to Figure 26 It shows Figure 14 The aberration characteristics of the optical system at room temperature, low temperature and high temperature are shown in the graph. Figure 24 to Figure 26 In the aberration diagram, spherical aberration (longitudinal spherical aberration), astigmatism field curve and distortion are measured from left to right.Figure 24 to Figure 26 In this case, the X-axis can represent focal length (mm) and distortion (%), and the Y-axis can represent the height of an image. Further, the graph for spherical aberration is a graph for light in wavelength bands of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for astigmatism and distortion aberration is a graph for light in a wavelength band of about 546 nm. In Figure 24 to Figure 26 In the aberration graph of FIG. 11, it can be explained that the closer each curve at room temperature, low temperature, and high temperature to the Y-axis, the better the aberration correction function. It can be seen that the optical system 1100 according to the second embodiment has a measurement value close to the Y-axis in almost all regions. That is, the optical system 1100 according to the second embodiment has improved resolution, and can have good optical performance not only in the center of the field of view (FOV) but also in the edge portion. Here, the low temperature is -20 degrees or less (for example, in the range of -20 to -40 degrees), the room temperature is in the range of 22 degrees ± 5 degrees or in the range of 18 to 27 degrees, and the high temperature can be in the range of 85 degrees or more (for example, in the range of 85 to 205 degrees). Therefore, it can be seen that Figure 24 to Figure 26 In this case, the X-axis can represent focal length (mm) and distortion (%), and the Y-axis can represent the height of an image. Further, the graph for spherical aberration is a graph for light in wavelength bands of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for astigmatism and distortion aberration is a graph for light in a wavelength band of about 546 nm. In

[0343] Table 6 compares the change in optical characteristics (such as EFL, BFL, F number (F#), TTL, and field of view (FOV_H)) at room temperature, low temperature, and high temperature in the optical system according to the second embodiment, and it can be seen that the change rate of the optical characteristics at low temperature is 5% or less (for example, 3% or less) relative to room temperature, and it can be seen that the change rate of the optical characteristics at low temperature is 5% or less (for example, 3% or less) relative to room temperature.

[0344] [Table 6]

[0345] Room temperature Low temperature High temperature Low temperature / room temperature High temperature / room temperature EFL(F) 14.7925 14.7329 14.8644 99.60％ 100.49％ BFL 0.0342 0.0356 0.0334 104.09％ 97.66％ F# 1.6065 1.6000 1.6143 99.60％ 100.49％ TTL 27.4600 27.4228 27.5038 99.86％ 100.16％ FOV_H 30.0000 30.1292 29.8489 100.43％ 99.50％

[0346] Therefore, as shown in Table 6, it can be seen that the change in optical characteristics (for example, the change rate of effective focal length (EFL), TTL, BFL, F number, and field of view (FOV_H)) is less than 10%, that is, less than 5%, for example, in the range of 0 to 5%, as the temperature changes from low temperature to high temperature. This makes it possible to design temperature compensation for plastic lenses even in the case of using at least one or two or more plastic lenses, thereby preventing a decrease in reliability of optical characteristics.

[0347] 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 center portion of the field of view (FOV) but also in the edge portion.

[0348] An optical system according to a third embodiment will be described.

[0349] Figure 27 is a side sectional view of an optical system and a camera module having the same according to the third embodiment; Figure 28 is a side sectional view for explaining a relationship between an nth lens and an (n-1)th lens according to the third embodiment; Figure 27 Figure 29 is a table showing aspherical coefficients of lenses in the optical system of Figure 27 Figure 30 is a table showing thicknesses of each lens and a space between adjacent lenses in the optical system of Figure 27 Figure 31 is a table showing sag values of lens surfaces of the first to seventh lenses in the optical system of Figure 27 Figure 32 is a table showing tilt angle values of lens surfaces of the first to seventh lenses in the optical system of Figure 27 Figure 33 is a table showing a position of an image sensor in the optical system according to Figure 27 Figure 34 to Figure 35 is a graph showing data of a diffraction modulation transfer function (MTF) of the optical system according to Figure 27 Figure 37 to Figure 39 is a graph showing data of aberration characteristics of the optical system according to Figure 27

[0350] Referring to Figure 27 and Figure 28 , the optical system 1200 includes a lens unit 300, and the lens unit 300 can include first to seventh lenses 301 to 307. The first to seventh lenses 301 to 307 can be sequentially disposed along an optical axis OA of the optical system 1200. Light corresponding to object information can pass through the first to seventh lenses 301 to 307 and the optical filter 900 and be incident on the image sensor 700.

[0351] The first lens 301 can be disposed closest to an object side. The first lens 301 can be disposed farthest from a sensor side. The first lens 301 can have a positive (+) refractive power on the optical axis OA. The first lens 301 can include a plastic material or a glass material, and can be, for example, a glass material. The first lens 301 made of a glass material can reduce changes in a center position and a radius of curvature due to temperature changes according to a surrounding environment, and can protect an incident side surface of the optical system 1200.

[0352] ​​​​​​​​The first surface S1 on the object side of the first lens 301 can be convex with respect to the optical axis, and the second surface S2 on the sensor side can be convex. The first lens 301 can have a shape in which both surfaces are convex. The first lens 301 is made of glass and can have an aspherical surface. Aspherical coefficients of the first surface S1 and the second surface S2 can be provided as L1S1, L1S2. Figure 29 The first lens 301 can be manufactured as a lens having an aspherical surface through injection molding of a glass material. The first lens 301 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 within a mold having an aspherical shape and through a heating and compression process.

[0353] The first lens 301 is provided by an aspherical glass material such that the glass material having high transmittance and refractive index has an aspherical surface, which can reduce the number of lenses in the optical system. When the temperature becomes a low temperature or a high temperature, the aspherical glass material can maintain optical performance at a constant level due to the glass material. In addition, since the aspherical surface is applied to the glass material, the refractive index of light does not significantly change even if the lens is designed to be thin. Therefore, unlike the optical system in which the first lens is designed to be the thickest in a horizontal viewing angle in the range of 30 to 50 degrees, the optical system of the present application can provide a thin first lens made of an aspherical glass material. Here, the thickness of the lens can include a center thickness and an edge thickness.

[0354] The second lens 302 can be disposed as the second from the object side. The second lens 302 can be disposed as the sixth from the sensor side. The second lens 302 can be disposed between the first lens 301 and the third lens 303. The second lens 302 can have a negative (-) refractive power on the optical axis OA. The second lens 302 can include a plastic or a glass material. For example, the second lens 302 can be provided by a glass material.

[0355] The third surface S3 of the second lens 302 on the object side can be concave with respect to the optical axis, and the fourth surface S4 on the sensor side can be convex. The second lens 302 can have a meniscus shape having a convex sensor side. The second lens 302 can be made of glass and can be spherical. At least one or both of the third surface S3 and the fourth surface S4 can be spherical.

[0356] A stop can be disposed around the sensor-side fourth surface S4 of the second lens 302. The stop can reduce the TTL within the field of view range, and can miniaturize the optical system. Accordingly, a decrease in yield due to the weight of the optical system can be prevented, and production efficiency can be improved. Further, by reducing the TTL within the horizontal field of view (FOV_H) of 25 degrees to 36 degrees, the optical system can be miniaturized.

[0357] The third lens 303 can be disposed as the third from the object side. The third lens 303 can be disposed as the fifth from the sensor side. The third lens 303 can be disposed between the second lens 302 and the fourth lens 304. The third lens 303 can have a positive (+) refractive power on the optical axis OA. The third lens 303 can include a plastic or a glass material. For example, the third lens 303 can be provided by a glass material.

[0358] The object-side fifth surface S5 of the third lens 303 can be convex with respect to the optical axis, and the sensor-side sixth surface S6 can be convex. The third lens 303 can have a shape in which both surfaces are convex on the optical axis OA. The third lens 303 is made of glass and can be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 can be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0359] Since both surfaces of the third lens 303 are disposed convexly, the number of lenses and the TTL of the optical system can be minimized, and light can be efficiently refracted. Further, when the radius of curvature of the fifth surface S5 of the third lens 303 is L3R1, and the radius of curvature of the sixth surface S6 is L3R2, the condition of L3R1<|L3R2| can be satisfied. Thereby, light can be efficiently refracted by the third surface S3, so that the effective diameter of the third lens 303 to the seventh lens 307 can be guided so as not to increase, and the TTL can be reduced. If L3R1>|L3R2|, many aberrations can occur on the object-side surface of the third lens 303, the refractive efficiency of light can be reduced on the sensor-side surface, the effective diameter of the rear lens can increase, and the TTL can also become larger.

[0360] The fourth lens 304 can be disposed as the fourth from the object side. The fourth lens 304 can be disposed as the fourth from the sensor side. The fourth lens 304 can be disposed between the third lens 303 and the fifth lens 305. The fourth lens 304 can have a positive (+) or negative (-) refractive power on the optical axis OA. The fourth lens 304 can have a positive (+) refractive power. The fourth lens 304 can have a positive (+) refractive power different from that of the fifth lens 305. The fourth lens 304 can include a plastic or a glass material. For example, the fourth lens 304 can be provided by a glass material. The fourth lens 304 can be provided by the same material as the fifth lens 305.

[0361] The object side seventh surface S7 of the fourth lens 304 can be convex, and the sensor side eighth surface S8 can be convex with respect to the optical axis. The fourth lens 304 can have a convex shape on both surfaces. The fourth lens 304 can be made of glass and can have a spherical surface. At least one or both of the seventh surface S7 and the eighth surface S8 can be spherical. The seventh surface S7 and the eighth surface S8 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0362] The fifth lens 305 can be disposed as the fifth from the object side. The fifth lens 305 can be disposed as the third from the sensor side. The fifth lens 305 can be disposed between the fourth lens 304 and the sixth lens 306. The fifth lens 305 can have a positive (+) or negative (-) refractive power on the optical axis OA. The fifth lens 305 can have a negative (-) refractive power. The fifth lens 305 can have a negative (-) refractive power different from that of the fourth lens 304. The fifth lens 305 can include a plastic or a glass material. For example, the fifth lens 305 can be provided by a glass material. The fifth lens 305 can be provided by the same material as the fourth lens 304.

[0363] The object side ninth surface S9 of the fifth lens 305 can be concave, and the sensor side tenth surface S10 can be concave with respect to the optical axis. The fifth lens 305 can have a shape in which both surfaces are concave. The fifth lens 305 is made of glass and can have a spherical surface. At least one surface of the ninth surface S9 and the tenth surface S10 can be a spherical surface. At least one or both of the ninth and tenth surfaces S9 and S10 of the fifth lens 305 can have no critical point from the optical axis OA to the end of the effective area.

[0364] The fourth lens 304 and the fifth lens 305 can be cemented. A bonding surface between the fourth lens 304 and the fifth lens 305 can be defined as an eighth surface S8. The eighth surface S8 can be the same surface as a ninth surface S9 of the fifth lens 305. An object side surface of the cemented lens 345 can be convex, and a sensor side surface can be concave. A spacing between the fourth lens 304 and the fifth lens 305 can be less than 0.01 mm, and can be attached with an adhesive. The spacing between the fourth lens 304 and the fifth lens 305 can be less than 0.01 mm from the optical axis OA to the end of the effective area. The fourth lens 304 and the fifth lens 305 can have opposite refractive powers. The combined refractive power of the fourth lens 304 and the fifth lens 305 can have a negative (-) refractive power.

[0365] A value of the radius of curvature of the cemented surface S8 of the cemented lens 345 can be greater than 90. For example, the value of the radius of curvature of the cemented surface S8 of the cemented lens 345 can be greater than 100. The cemented surface S8 of the cemented lens 345 can be formed in a gentle shape. Thereby, the cementing process of the fourth lens 304 and the fifth lens 305 forming the cemented lens 345 is advantageous, and the cementing retention strength can be increased.

[0366] A product of the refractive power of the object side fourth lens 304 and the refractive power of the sensor side fifth lens 305 of the cemented lens 345 can be less than 0. A product of the focal length of the object side fourth lens 305 and the focal length of the sensor side fifth lens 305 of the cemented lens 345 can be less than 0. Accordingly, the aberration characteristics of the optical system can be improved. If the refractive powers of the two lenses of the cemented lens 345 are the same, there is a limit to the improvement in the aberration.

[0367] The combined refractive power of the cemented lens 345 has a negative (-) refractive power, and can have a negative (-) refractive power with respect to the third lens 303 on the object side and the sixth lens 306 on the sensor side of the cemented lens 345. Accordingly, the fourth lens 304, the cemented lens 345, and the fifth lens 305 can refract a portion of the incident light in the optical axis direction.

[0368] An effective diameter of the fourth lens 304 can be greater than a diagonal length of the image sensor 700. The effective diameter of the fourth lens 304 is an average of the effective diameters of the seventh surface S7 and the eighth surface S8, and can be greater than the diagonal length of the image sensor 700. An effective diameter of the fifth lens 305 can be less than the effective diameter of the fourth lens 304 and greater than the diagonal length of the image sensor 700. An effective diameter of the seventh surface S7 of the fourth lens 304 can be greater than the diagonal length of the image sensor 700, and an effective diameter of the tenth surface S10 of the fifth lens 305 can be less than the diagonal length of the image sensor 700.

[0369] When the fifth lens 305 is a spherical lens and the seventh lens 307 is an aspherical lens, a difference in effective diameter between the object side ninth surface S9 of the fifth lens 305 and the sensor side tenth surface S10 can be set to be the largest. For example, when the effective diameters of the ninth surface S9 and the sensor side tenth surface S10 of the fifth lens 305 are CA51 and CA52, a condition of CA51 > CA52 is satisfied, and a difference between CA51 and CA52 can be the largest among the differences in effective diameter between the object side surface and the sensor side surface of each lens. Accordingly, the difference in effective diameter between the object side surface and the sensor side surface of the fifth lens 305 can be set to be maximized in order to effectively guide light to travel through the aspherical lens having a relatively small effective diameter. Accordingly, a more slim optical system can be provided. The effective diameter of the fifth lens 305 can satisfy a condition of 1.1 < CA51 / CA52 < 1.5.

[0370] The cemented lens 345 is cemented with a glass lens having a different refractive index, has a spherical refractive surface, and at least one lens disposed closer to the sensor than the cemented lens 345 is an aspherical lens, so that spherical aberration can be compensated. In addition, at least one lens among the lenses disposed closer to the sensor than the cemented lens 345 is an aspherical lens and is disposed to have a small effective diameter, so that light can be effectively guided to travel through the aspherical lens to the image sensor 700. Since the cemented lens 345 is disposed between the aspherical lenses and between the spherical lenses, chromatic aberration correction can be more effective. By positioning the cemented lens 345 within the optical system, the TTL can be reduced.

[0371] The sixth lens 306 can be disposed as the sixth lens from the object side. The sixth lens 306 can be disposed as the second lens from the sensor side. The sixth lens 306 can be disposed between the fifth lens 305 and the seventh lens 307. The sixth lens 306 can have a positive (+) or negative (-) refractive power on the optical axis OA. The sixth lens 306 can have a positive (+) refractive power. The sixth lens 306 can include a plastic or a glass material. For example, the sixth lens 306 can be provided by a plastic material.

[0372] The sixth lens 306 can have a convex shape on the object side eleventh surface S11 and a concave shape on the sensor side twelfth surface S12 with respect to the optical axis. The sixth lens 306 can have a convex meniscus shape on the object side. At least one or both of the eleventh surface S11 and the twelfth surface S12 can be aspherical. Aspherical coefficients of the eleventh surface S11 and the twelfth surface S12 can be provided as Figure 29 L1 and L2 of L6 of

[0373] The eleventh surface S11 of the sixth lens 306 can be provided without a critical point from the optical axis OA to the end of the effective region. The twelfth surface S12 of the sixth lens 306 can include a critical point from the optical axis OA to the end of the effective region. When the twelfth surface S12 has a critical point, it can be located in a range of 20% to 30% of the effective radius r62 from the optical axis OA, preferably in a range of 25% to 28% of the effective radius r62 from the optical axis OA. The critical point of the twelfth surface S12 can be located in a range of 1.0 mm to 1.5 mm from the optical axis OA, preferably in a range of 1.1 mm to 1.2 mm from the optical axis OA.

[0374] The seventh lens 307 can be provided closest to the sensor side. The seventh lens 307 can be provided farthest to the object side. The seventh lens 307 can have a positive (+) or negative (-) refractive power on the optical axis OA. The seventh lens 307 can have a negative (-) refractive power. The seventh lens 307 can include a plastic or glass material. For example, the seventh lens 307 can be made of a plastic material.

[0375] On the optical axis, the object-side thirteenth surface S13 of the seventh lens 307 can be convex, and the sensor-side fourteenth surface S14 can be concave. The seventh lens 307 can have a meniscus shape convex toward the object side. At least one of the thirteenth surface S13 and the fourteenth surface S14 can be an aspheric surface. For example, both the thirteenth surface S13 and the fourteenth surface S14 can be aspheric. The aspheric coefficients of the thirteenth surface S13 and the fourteenth surface S14 can be provided as S1 and S2 of L7 in Equation 1. Figure 29

[0376] The thirteenth surface S13 of the seventh lens 307 can have a critical point from the optical axis OA to the end of the effective region. When the thirteenth surface S13 has a critical point, it can be located in a range of 45% to 50% of the effective radius r71 from the optical axis OA, preferably in a range of 46% to 49% of the effective radius r71 from the optical axis OA. The critical point of the thirteenth surface S13 can be located in a range of 1.7 mm to 2.2 mm from the optical axis OA, preferably in a range of 1.9 mm to 2.0 mm from the optical axis OA. The thirteenth surface S13 having such a critical point can refract incident light to the central portion and the edge portion and improve aberration.

[0377] ​The fourteenth surface S14 of the seventh lens 307 can have a critical point from the optical axis OA to the end of the effective region. When the fourteenth surface S14 has a critical point, it can be located in a range of 65% to 70% of the effective radius r72 from the optical axis OA, preferably in a range of 67% to 70% of the effective radius r72 from the optical axis OA. The critical point of the fourteenth surface S14 can be located in a range of 3 mm to 3.3 mm from the optical axis OA, preferably in a range of 3.1 mm to 3.2 mm from the optical axis OA.

[0378] The critical point of the thirteenth surface S13 and the fourteenth surface S14 is a point where the sign of the slope value with respect to the optical axis OA and a direction perpendicular to the optical axis OA changes from positive (+) to negative (-) or from negative (-) to positive (+), and can represent a point where the slope value is 0. In addition, the critical point of the thirteenth surface S13 and the fourteenth surface S14 can be a point where the slope value of the tangent line passing through the lens surface first increases and then decreases, or first decreases and then increases.

[0379] The seventh lens 307 can be a plastic lens closest to the image sensor 700. In addition, by arranging two or more plastic lenses adjacent to the image sensor 700, aberrations such as spherical aberration and chromatic aberration can be improved by the lens surface having an aspherical surface, and the influence on resolution can be controlled. In addition, by arranging a plastic lens as a lens adjacent to the image sensor 700, the plastic lens can be insensitive to assembly tolerance compared to a glass lens. In other words, insensitivity to assembly tolerance means that even if assembly is performed slightly differently than the design during assembly, the optical performance can not be significantly affected. In addition, by providing two lenses 306 and 307 adjacent to the image sensor 700 with plastic, the optical performance can be improved by the lens surface having an aspherical surface, and for example, aberration characteristics can be improved and degradation of resolution can be prevented.

[0380] The sixth lens 306 and the seventh lens 307 are disposed to be spaced apart from each other, but can include the characteristics of a cemented lens. The sixth lens 306 and the seventh lens 307 can have opposite refractive powers. The product of the refractive power of the sixth lens 306 and the refractive power of the seventh lens 307 can be less than 0. The product of the focal length of the sixth lens 306 and the focal length of the seventh lens 307 can be less than 0. Accordingly, the aberration characteristics of the optical system can be improved. If the signs of the refractive powers of the two lenses having the characteristics of a cemented lens are the same, there is a limit to the improvement in aberration.

[0381] The sixth lens 306 and the seventh lens 307 can be made of the same material. The sixth lens 306 and the seventh lens 307 can be made of a plastic material. The sixth lens 306 and the seventh lens 307 can be made of the same material as the cemented lens 345.

[0382] [Table 7]

[0383]

[0384]

[0385] Table 7 shows surface numbers (surfaces), radii of curvature (radii), center thicknesses of each lens or distances between lens surfaces (thicknesses), refractive indices (nd), Abbe numbers (vd), effective radii (half aperture diameters), and focal lengths (focal lengths) of lenses according to the third embodiment of the present application. At this time, units of the radii of curvature and the thicknesses or distances can be mm.

[0386] [Table 8]

[0387] Category Value Category Value F 14.6648 ET1 1.4040 F2_7 23.9416 ET2 7.0149 F3_7 16.7426 ET3 0.9165 F4_7 116.6020 ET4 1.3846 F5_7 -9.6256 ET5 4.6734 F6_7 38.7736 ET6 1.5282 F4_5 -306.7020 ET7 1.8644 ΣIndex 11.6521 F number 1.6063 ΣAbbe 313.5836 FOV_D 34.2278 ΣCT 20.06889 EPD 9.1296 ΣCG 5.41162 BFL 2.4195 CA_max 11.892 TD 25.4805 CA_min 8.524 ImgH 4.6300 CA_Aver 9.679 SD 16.0679 CT_max 6.4282 TTL 27.9000 CT_min 1.3000 GLca_Aver 10.131 CT_Aver 2.86698 PLca_Aver 8.547 Image sensor 3840*2160

[0388] Table 8 shows categories of the above mathematical expressions in the optical system 1200 of the embodiment, including a total top length (TTL) (mm) of the optical system 1200, a back focal length (BFL), an effective focal length F (mm), ImgH (mm), an effective diameter CA (mm), a thickness (mm), a TTL (mm), TD (mm) which is an optical axis distance from the first surface S1 to the fourteenth surface S14, composite focal lengths F2_7, F3_7, F4_7, F5_7, F6_7, and F4_5 (mm) of the first lens to the seventh lens, a sum of refractive indices, a sum of Abbe numbers, a sum of thicknesses (mm), a sum of spacings between adjacent lenses, an effective diameter characteristic, a sum of refractive indices of glass lenses, a sum of refractive indices of plastic materials, a field of view angle FOV_H (degrees), an edge thickness ET, an F number, and the like.

[0389] As shown in Figure 27 and Figure 28 , center thicknesses of the first lens 301 to the seventh lens 307 are denoted by CT1 to CT7, edge thicknesses at ends of effective regions of each lens are denoted by ET1 to ET7, center spacings between two adjacent lenses are denoted by CG1 to CG6, and edge spacings between edges of each lens are denoted by EG1 to EG6. Here, the center thickness of the cemented lens 345 is CT45, and the edge thickness is denoted by ET45.

[0390] Referring to Figure 28 , the back focal length (BFL) is an optical axis distance from the image sensor 700 to the center of the last lens. In Figure 27 , the TTL is an optical axis distance from the center of the first surface S1 of the first lens 301 to the upper surface of the image sensor 700.

[0391] As shown in Figure 29As shown, in the lens of the lens unit 300 in the third embodiment, the lens surfaces of the first lens 301, the sixth lens 306, and the seventh lens 307 can include aspherical surfaces having 30th order aspherical surface coefficients. For example, the first lens 301, the sixth lens 306, and the seventh lens 307 can include lens surfaces having 30th order aspherical surface coefficients. As described above, since the aspherical surface having the 30th order aspherical coefficient (a value other than "0") can significantly change the aspherical shape of the edge portion, the optical performance of the edge portion of the field of view (FOV) can be well corrected.

[0392] As Figure 30 shown, the thicknesses T1 to T7 of the first to seventh lenses 301, 302, 303, 304, 305, 306, and 307 and the intervals G1 to G6 between the adjacent two lenses can be set. As Figure 30 shown, the thicknesses T1 to T7 of each lens in the Y-axis direction can be expressed with an interval of 0.1 mm or more or 0.2 mm or more, and the intervals G1 to G6 between each lens can be expressed with an interval of 0.1 mm or more or 0.2 mm or more.

[0393] When comparing the absolute values of the radii of curvature of each lens, the radius of curvature of the sixth surface S6 of the third lens 303 on the optical axis OA can be the largest among the lenses, and the radius of curvature of the tenth surface S10 of the fifth lens 305 can be the smallest among the lenses. The difference between the largest radius of curvature and the smallest radius of curvature can be 25 times or more, for example, 26 to 30 times. The radius of curvature of the sensor side surface of the glass material lens disposed on the object side of the plastic material lens can be the smallest among the lenses. The radius of curvature of the sensor side surface of the fifth lens 305 disposed on the object side of the sixth lens 306 can be the smallest among the lenses.

[0394] Since the effective diameter of the plastic lens is smaller than the effective diameter of the glass lens, the lens disposed on the object side of the plastic lens can have a strong refractive power to refract the light passing through the plastic lens. In addition, the radius of curvature of the lens surface can be small to enhance the refractive power.

[0395] Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 10 mm or less among the object side surface and the sensor side surface can be two or less. The absolute value of the radius of curvature of the sensor side surface (the tenth surface) S10 of the fifth lens 305 and the sensor side surface (the fourteenth surface) S14 of the seventh lens 307 can be 10 mm or less. Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 10 mm or more and 20 mm or less among the object side surface and the sensor side surface can be three or more and five or less. The absolute value of the radius of curvature of the object side surface (the fifth surface) S5 of the third lens 303, the object side surface (the seventh surface) S7 of the fourth lens 304, and the object side surface (the eleventh surface) S11 of the sixth lens 306 can be 10 mm or more and 20 mm or less. Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 60 mm or more among the object side surface and the sensor side surface can be at least one and not more than four. The absolute value of the radius of curvature of the sensor side surface (the sixth surface) S6 of the third lens 303 can be at least 60 mm.

[0396] In a temperature compensation design in which resolution needs to be maintained even when the temperature changes from -40 degrees to 100 degrees, a larger radius of curvature can be advantageous. In a design for temperature compensation, an aluminum lens barrel can be used as a lens barrel. The manufacturing tolerance of the aluminum lens barrel is large, so the misalignment of the optical axis of each lens is large when the lens is assembled. Therefore, by designing a larger radius of curvature, the sensitivity to the manufacturing tolerance can be reduced.

[0397] Reference Figure 32 The inclination angle of the lens surface can be expressed as a value in radians, which is the slope of the lens surface at a point on the lens surface having a 0.1 pitch with respect to the Y-axis perpendicular to the optical axis, converted to a tangent value. Regarding the inclination angle of the lens surface, the inclination angle of the object side surface (the first surface) S1 of the first lens 301 can be the smallest, excluding the cemented lens among the first lens to the seventh lens. Among the object side surfaces and the sensor side surfaces of the first lens to the seventh lens, the number of lenses having a value smaller than the absolute value of the inclination angle of the object side surface of the aspherical glass material can be five or less. Preferably, the number of lenses smaller than the absolute value of the inclination angle of the object side surface (the first surface) S1 of the first lens 301 can be two. The absolute value of the inclination angle of the sensor side surface (the eighth surface) S8 of the fourth lens 304 and the object side surface (the ninth surface) S9 of the fifth lens 305 can be smaller than the absolute value of the inclination angle of the object side surface (the first surface) S1 of the first lens 301.

[0398] The shape of the first lens 301 having an aspherical shape can be designed to be flat. If the aspherical surface is located at the most front in the optical system 1200, the performance of the lens is improved, but the assembly property can be lowered. To improve the assembly property, the shape of the first lens 301 should be designed to be flat. To minimize the influence on the lens disposed at the sensor side when the lens is assembled in the lens barrel, it can be designed to have almost no curvature. 2

[0399] 3With respect to the optical axis, when the center thickness of the lens is described, the center thickness CT2 of the second lens 302 is the largest among the lenses, and the center thickness CT7 of the seventh lens 307 is the smallest among the lenses. The difference between the largest center thickness and the smallest center thickness among the lenses can be in the range of 4.5 mm or more and 5.5 mm or less. 4

[0400] 5When the center spacing CG between the lenses is explained, the center spacing CG5 between the fifth lens 305 and the sixth lens 306 can be the largest, and the center spacing CG2 between the second lens 302 and the third lens 303 and the center spacing CG3 between the third lens 303 and the fourth lens 304 can be the smallest. Here, the smallest center spacing does not include the cemented surface of the cemented lens 345. The difference between the largest center spacing and the smallest center spacing among the spacings of the lenses spaced apart can be 1.5 mm or more, for example, in the range of 2 mm to 2.5 mm. 6

[0401] 7When the effective diameter is explained, the lens having the largest effective diameter can be disposed between the first lens 301 closest to the object and the seventh lens 307 closest to the image sensor 700. The lens having the largest effective diameter can be a glass lens. The lens having the largest effective diameter can be disposed between the first lens 301 and the cemented lens 345. The lens having the largest effective diameter can be the first lens 301. Here, the effective diameter is the average of the effective diameter of the object side surface and the effective diameter of the sensor side surface of each lens. The lens surface having the largest effective diameter can be the first surface S1 of the first lens 301. 8

[0402] 9The lens having the smallest effective diameter can be one of the cemented lenses or one of the plastic lenses, for example, the sixth lens 306 or the seventh lens 307 adjacent to the image sensor 700. For example, the effective diameter of the fifth lens 305 can be the smallest within the lens unit 300. The lens surface having the smallest effective diameter can be the tenth surface S10 of the fifth lens 305. The effective diameter of the plastic lens can be smaller than that of the glass lens. The plastic lens can be disposed adjacent to the image sensor. 10

[0403] 11An effective diameter of each of the first to fourth lenses 301 to 304 adjacent to the object side can be greater than effective diameters of the fifth to seventh lenses 305, 306, and 307 adjacent to the sensor side. The effective diameters of the first to fourth lenses 301 to 304 can be greater than a diagonal length of the image sensor 700. An average effective diameter of the seventh lens 307 can be less than the diagonal length of the image sensor 700. Accordingly, light incident through the plurality of lenses arranged along the optical axis can be guided to the image sensor 700.

[0404] When explaining the refractive index, the refractive index of the fourth lens 304 can be the greatest among the lenses, and can be greater than 1.77, for example, greater than 1.8. Either one or both of the third lens 303 and the sixth lens 306 can have the smallest refractive index among the lenses. For example, the refractive index of the sixth lens 306 can be the smallest among the lenses, and can be less than 1.6, for example, less than 1.55. The difference between the greatest refractive index and the smallest refractive index can be 0.2 or more. By providing a high refractive index lens made of glass closest to the object, and providing the lens adjacent to the image sensor 700 and the lens adjacent to the glass lens with a low refractive index made of plastic, the incidence efficiency can be increased, and the refractive power between the glass lens and the plastic lens can be adjusted to guide it to the image sensor 700.

[0405] When comparing the Abbe number, the Abbe number of the third lens 303 is the greatest among the lenses, and can be 70 or more. The Abbe number of the seventh lens 307 is the smallest among the lenses, and can be 25 or less. The difference between the greatest refractive index and the smallest Abbe number can be 50 or more. By making the Abbe number of the third lens 303 adjacent to the cemented lens 345 the greatest and making the Abbe number of the seventh lens 307 having a low refractive index adjacent to the image sensor 700 the smallest, 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 it to the image sensor 700.

[0406] The focal lengths F2, F5, and F7 of the second, fifth, and seventh lenses 302, 305, and 307 can have a negative (-) sign. The second, fifth, and seventh lenses 302, 305, and 307 can have a negative (-) refractive power. The focal lengths F1, F3, F4, and F6 of the first, third, fourth, and sixth lenses 301, 303, 304, and 306 can have a positive (+) sign. The first, third, fourth, and sixth lenses 301, 303, 304, and 306 can have a positive (+) refractive power. The third and fourth lenses 303 and 304 having a positive (+) refractive power can be disposed on the sensor side of the second lens 302 having a negative (-) refractive power. Thereby, light incident on the object side can move away from the optical axis direction and then be again gathered in the optical axis direction, thereby forming a stable light path.

[0407] Further, the sixth lens 306 and the seventh lens 307, which are adjacently disposed lenses, can satisfy the following conditions.

[0408] Condition 1: refractive index of lens having positive refractive power < refractive index of lens having negative refractive power Condition 2: dispersion of lens having positive refractive power > dispersion of lens having negative refractive power

[0409] Here, among the plastic lenses, the sixth lens 306 has positive refractive power and the seventh lens 307 has negative refractive power, so that according to the conditions 1 and 2, the refractive index of the sixth lens 306 is smaller than that of the seventh lens 307, and the dispersion value of the sixth lens 306 is greater than that of the seventh lens 307. The chromatic aberration occurring in the plastic lenses can be corrected by the plastic lenses. Further, since the sixth lens 306 and the seventh lens 307, which are adjacently disposed plastic lenses, 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, the chromatic aberration occurring in the plastic lenses can be compensated by the plastic lenses.

[0410] The optical system has chromatic aberration, and the chromatic aberration is corrected by using a cemented lens or two lenses disposed in series. The lenses repeatedly contract and expand as the temperature changes from low temperature to high temperature. Since the lens characteristics of lenses of the same material change by the same amount according to the temperature change, the chromatic aberration between the lenses of the same material can be effectively corrected even if the temperature changes.

[0411] Therefore, in the third embodiment of the present application, the chromatic aberration occurring in the plastic lenses is corrected by using the cemented lens 345, the sixth lens 306, and the seventh lens 307.

[0412] The fourth lens 304 and the fifth lens 305, which are the cemented lenses, can compensate for the chromatic aberration occurring in the glass lenses by satisfying 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. The refractive index difference is rounded to the third digit after the decimal point, and the Abbe number difference is rounded to the first digit after the decimal point for numerical comparison.

[0413] When the focal length is compared in absolute value, the focal length of the first lens 301 is the largest among the lenses, and can be 35 or more and 50 or less. Among the lenses, the first lens 301 made of glass can have the largest focal length and the smallest refractive power. The focal length of the fifth lens 305 is the smallest among the lenses, and the absolute value of the focal length of the fifth lens 305 can be 5 or more and 10 or less. Among the lenses, the fifth lens 305 made of glass can have the smallest focal length and the largest refractive power. Since the lens made of a plastic material having a small refractive power is disposed on the sensor side of the fifth lens 305, the refractive power of the fifth lens 305 can be increased.

[0414] Among the lenses other than the cemented lens 345, the lens having the smallest focal length can be the sixth lens 306. The difference between the largest focal length and the smallest focal length can be 30 or more or 50 or less. Thus, the optical system can have improved MTF characteristics, aberration control characteristics, resolution characteristics, and the like in a set view angle range, and can have good optical performance in an edge portion of the view angle.

[0415] The thickness T1 of the first lens 301 can be a difference of 1 times or more, for example, a difference in a range of 1 to 1.2 times, between the largest thickness and the smallest thickness, and the central thickness CT1 can be the largest, and the edge thickness ET1 can be the smallest. The thickness T2 of the second lens 302 can be the largest thickness in a range of 1 to 1.2 times the smallest thickness. The second lens 302 can have the smallest central thickness CT2 and the largest edge thickness ET2. The thickness T3 of the third lens 303 can be the largest at the center and the smallest at the edge, and the largest thickness can be in a range of 1.5 to 2 times the smallest thickness. The thickness T4 of the fourth lens 304 can be the largest at the center and the smallest at the edge, and the largest thickness can be in a range of 1.6 to 2.2 times the smallest thickness. The thickness T5 of the fifth lens 305 can be the smallest at the center and the largest at the edge, and the largest thickness can be in a range of 1.2 to 1.5 times the smallest thickness. The thickness T6 of the sixth lens 306 can be the largest at the center and the smallest at the edge, and the largest thickness can be in a range of 1 to 1.2 times the smallest thickness. The thickness T7 of the seventh lens 307 can be the smallest at the center and the largest at the edge, and the largest thickness can be in a range of 1 to 1.2 times the smallest thickness.

[0416] The central thickness CT45 of the cemented lens 345 can be smaller than the edge thickness ET45 thereof. The central thickness CT45 of the cemented lens 345 is a distance from the center of the object side seventh surface S7 of the fourth lens 304 to the center of the tenth surface S10 of the fifth lens 305. The edge thickness ET45 is a distance in the optical axis direction from the end of the effective region of the seventh surface S7 to the tenth surface S10. The largest thickness of the cemented lens 345 can be at the edge portion, and the smallest thickness can be at the center portion, where the largest thickness can be in a range of 1 to 1.2 times the smallest thickness.

[0417] Among the intervals G1 to G6 between the lenses, the first interval G1 between the first lens 301 and the second lens 302 can have a maximum value in the center portion and a minimum value in the edge portion. The second interval G2 between the second lens 302 and the third lens 303 can have a maximum value in the edge portion and a minimum value in the center portion. The third interval G3 between the third lens 303 and the fourth lens 304 can have a maximum value in the edge portion and a minimum value in the center portion. The fifth interval G5 between the fifth lens 305 and the sixth lens 306 can have a maximum value in the center portion and a minimum value in the edge portion. The sixth interval G6 between the sixth lens 306 and the seventh lens 307 can have a maximum value in the center portion and a minimum value in the edge portion.

[0418] As Figure 33 indicated in Figure 27 the optical system and the camera module, at 1 field of view which is an end of a diagonal line length of the image sensor, a chief ray angle (CRA) can be 10 degrees or more, for example, in a range of 10 degrees to 35 degrees or 10 degrees to 25 degrees. Further, a difference in the chief ray angle from a low temperature (-40 degrees) to a high temperature (95 degrees) can be 1 degree or less. Therefore, even if the temperature changes from the low temperature to the high temperature, the difference in the chief ray angle is not large, and stable optical performance can be achieved.

[0419] Figures 34-36 is a graph showing a diffraction modulation transfer function (MTF) at room temperature, a low temperature, and a high temperature in the optical system of Figure 27 , and is a graph showing modulation according to a spatial frequency. As Figures 34-36 indicated in the third embodiment of the present application, a deviation in the MTF at a low temperature or a high temperature from a room temperature can be less than 10%, i.e., 7% or less.

[0420] Figures 37-39 is a graph showing an aberration characteristic at room temperature, a low temperature, and a high temperature in the optical system of Figure 27 . In the aberration graph of Figures 37-39 , from left to right, a spherical aberration (longitudinal spherical aberration), a coma field curve, and a distortion are measured. In Figures 37-39 , the X axis can represent a focal length (mm) and a distortion degree (%), and the Y axis can represent a height of an image. Further, the graph for the spherical aberration is a graph for light in a wavelength band of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for the coma and distortion aberration is a graph for light in a wavelength band of about 546 nm. In Figures 37-39In the aberration map, it can be explained 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 1200 according to the third embodiment has a measurement value close to the Y-axis in almost all regions. That is, the optical system 1200 according to the third embodiment has improved resolution, and can have good optical performance not only in the center of the field of view (FOV) but also in the edge portion. Here, the low temperature is -20 degrees or less (for example, in the range of -20 to -40 degrees), the room temperature is in the range of 22 degrees ± 5 degrees or in the range of 18 to 27 degrees, and the high temperature can be in the range of 85 degrees or more, for example, in the range of 85 to 305 degrees. Therefore, it can be seen that Figures 37-39 the decrease in luminance ratio (modulation) from low temperature to high temperature is less than 10%, for example, 5% or less, or almost no change.

[0421] Table 9 compares the change in optical characteristics (such as EFL, BFL, F number (F#), TTL, and field of view (FOV_H)) at room temperature, low temperature, and high temperature in the optical system according to the third embodiment, and it can be seen that the change rate of the optical characteristics at low temperature is 5% or less (for example, 3% or less) relative to room temperature, and it can be seen that the change rate of the optical characteristics at high temperature is 5% or less (for example, 3% or less) relative to room temperature.

[0422] [Table 9]

[0423] Room temperature Low temperature High temperature Low temperature / Room temperature High temperature / Room temperature EFL(F) 14.6648 14.6074 14.7336 99.61％ 100.47％ BFL 0.0350 0.0365 0.0337 304.29％ 96.29％ F# 1.6063 1.6002 1.6136 99.62％ 100.45％ TTL 27.8600 27.8248 27.9015 99.87％ 100.15％ FOV_H 30.0000 30.1193 29.8605 100.40％ 99.54％

[0424] Therefore, as shown in Table 9, it can be seen that the change in optical characteristics (for example, change rate of effective focal length (EFL), TTL, BFL, F number, and field of view (FOV_H)) is less than 10%, that is, less than 5%, for example, in the range of 0 to 5% as the temperature changes from low temperature to high temperature. This makes it possible to design temperature compensation for plastic lenses even in the case of using at least one or two or more plastic lenses, thereby preventing a decrease in reliability of optical characteristics.

[0425] The optical system of the third 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 center portion of the field of view (FOV) but also in the edge portion.

[0426] An optical system according to a fourth embodiment of the present application will be described.

[0427] Figure 40 is a side sectional view of an optical system and a camera module having the optical system according to the fourth embodiment; Figure 41 is a graph for explaining the change in optical characteristics at room temperature, low temperature, and high temperature in the optical system according to the fourth embodiment; Figure 40A cross-sectional view showing the relationship between the n-th lens and the (n-1)-th lens; Figure 42 It shows Figure 40 Table of aspheric coefficients of lenses in optical systems; Figure 43 It shows Figure 40 A table showing the thickness of each lens and the spacing between adjacent lenses in the optical system; Figure 44 It shows Figure 40 a table of sag values ​​of lens surfaces of first to seventh lenses in the optical system; Figure 45 It shows Figure 40 a table of inclination angle values ​​of lens surfaces of first to seventh lenses in the optical system; Figure 46 It shows that according to Figure 40 The position of the image sensor in the optical system, and the table of chief ray angle (CRA) data at room temperature, low temperature and high temperature; Figures 47-48 Is to show about Figure 40 a graph of diffraction modulation transfer function (MTF) data of an optical system at room temperature, low temperature, and high temperature; and Figures 49-51 Is to show about Figure 40 A graph showing the aberration characteristics of an optical system at room temperature, low temperature, and high temperature.

[0428] refer to Figure 40 and Figure 41 The optical system 1300 includes a lens unit 400, and the lens unit 400 may include first to seventh lenses 401 to 407. The first to seventh lenses 401 to 407 may be sequentially arranged along the optical axis OA of the optical system 1300. Light corresponding to object information may pass through the first to seventh lenses 401 to 407 and the optical filter 900 and be incident on the image sensor 700.

[0429] The first lens 401 may be positioned closest to the object side. The first lens 401 may be positioned farthest from the sensor side. The first lens 401 may have a negative (-) refractive power on the optical axis OA. The first lens 401 may be made of a plastic material or a glass material, and may be, for example, a glass material. The first lens 401 made of a glass material can reduce changes in the center position and curvature radius due to temperature changes in the surrounding environment and protect the incident side surface of the optical system 1300.

[0430] The first surface S1 on the object side of the first lens 401 may be convex with respect to the optical axis, and the second surface S2 on the sensor side may be convex. The first lens 401 may have a shape in which both surfaces are convex. The first lens 401 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 provided as Figure 41L1S1, L1S2 of the first lens 401. The first lens 401 can be manufactured as a lens having an aspherical surface through injection molding of a glass material. The first lens 401 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 within a mold having an aspherical shape and through a heating and compression process.

[0431] The first lens 401 is provided by an aspherical glass material such that the glass material having high transmittance and refractive index has an aspherical surface, which can reduce the number of lenses in the optical system. When the temperature becomes a low temperature or a high temperature, the aspherical glass material can maintain optical performance at a constant level due to the glass material. In addition, since the aspherical surface is applied to the glass material, the refractive index of light does not significantly change even if the lens is designed to be thin. Accordingly, unlike the optical system in which the first lens is designed to be the thickest in a horizontal viewing angle in the range of 30 to 50 degrees, the optical system of the present disclosure can provide a thin first lens made of an aspherical glass material. Here, the thickness of the lens can include a center thickness and an edge thickness.

[0432] The second lens 402 can be disposed as the second from the object side. The second lens 402 can be disposed as the sixth from the sensor side. The second lens 402 can be disposed between the first lens 401 and the third lens 403. The second lens 402 can have a negative (-) power on the optical axis OA. The second lens 402 can include a plastic or a glass material. For example, the second lens 402 can be provided by a glass material.

[0433] The object side third surface S3 of the second lens 402 can be concave and the sensor side fourth surface S4 can be convex with respect to the optical axis. The second lens 402 can have a meniscus shape having a convex sensor side. The second lens 402 can be made of glass and can be spherical. At least one or both of the third surface S3 and the fourth surface S4 can be spherical.

[0434] An aperture stop can be disposed around the sensor side fourth surface S4 of the second lens 402. The aperture can reduce the TTL within the field of view range and can miniaturize the optical system. Accordingly, a reduction in yield due to the weight of the optical system can be prevented, and production efficiency can be improved. In addition, by reducing the TTL within the horizontal field of view (FOV_H) of 25 to 36 degrees, the optical system can be miniaturized.

[0435] The third lens 403 can be disposed as the third from the object side. The third lens 403 can be disposed as the fifth from the sensor side. The third lens 403 can be disposed between the second lens 402 and the fourth lens 404. The third lens 403 can have a positive (+) refractive power on the optical axis OA. The third lens 403 can include a plastic or a glass material. For example, the third lens 403 can be provided by a glass material.

[0436] The object side fifth surface S5 of the third lens 403 can be convex with respect to the optical axis, and the sensor side sixth surface S6 can be convex. The third lens 403 can have a shape in which both surfaces are convex on the optical axis OA. The third lens 403 is made of glass and can be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 can be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0437] Since both surfaces of the third lens 403 are disposed convexly, it is possible to minimize the number of lenses and the TTL of the optical system, and to effectively refract light. In addition, when the radius of curvature of the fifth surface S5 of the third lens 403 is L3R1 and the radius of curvature of the sixth surface S6 is L3R2, it is possible to satisfy the condition of L3R1<|L3R2|. Thereby, light can be effectively refracted by the third surface S3 so that the effective diameter of the third lens 403 to the seventh lens 407 can be guided so as not to increase, and the TTL can be reduced. If L3R1>|L3R2|, many aberrations can occur on the object side surface of the third lens 403, the refractive efficiency of light on the sensor side surface can be reduced, the effective diameter of the rear lens can increase, and the TTL can also become larger.

[0438] The fourth lens 404 can be disposed as the fourth from the object side. The fourth lens 404 can be disposed as the fourth from the sensor side. The fourth lens 404 can be disposed between the third lens 403 and the fifth lens 405. The fourth lens 404 can have a positive (+) or negative (-) refractive power on the optical axis OA. The fourth lens 404 can have a positive (+) refractive power. The fourth lens 404 can have a positive (+) refractive power different from that of the fifth lens 405. The fourth lens 404 can include a plastic or a glass material. For example, the fourth lens 404 can be provided by a glass material. The fourth lens 404 can be provided by the same material as the fifth lens 405.

[0439] The object-side seventh surface S7 of the fourth lens 404 can be convex with respect to the optical axis, and the sensor-side eighth surface S8 can be convex. The fourth lens 404 can have a convex shape on both surfaces. The fourth lens 404 can be made of glass and can have a spherical surface. At least one or both of the seventh surface S7 and the eighth surface S8 can be spherical. The seventh surface S7 and the eighth surface S8 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0440] The fifth lens 405 can be disposed as the fifth from the object side. The fifth lens 405 can be disposed as the third from the sensor side. The fifth lens 405 can be disposed between the fourth lens 404 and the sixth lens 406. The fifth lens 405 can have a positive (+) or negative (-) refractive power on the optical axis OA. The fifth lens 405 can have a negative (-) refractive power. The fifth lens 405 can have a different negative (-) refractive power from that of the fourth lens 404. The fifth lens 405 can include a plastic or glass material. For example, the fifth lens 405 can be provided by a glass material. The fifth lens 405 can be provided by the same material as the fourth lens 404.

[0441] The object-side ninth surface S9 of the fifth lens 405 can be concave with respect to the optical axis, and the sensor-side tenth surface S10 can be concave. The fifth lens 405 can have a shape in which both surfaces are concave. The fifth lens 405 is made of glass and can have a spherical surface. At least one of the ninth surface S9 and the tenth surface S10 can be a spherical surface. At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 405 can have no critical point from the optical axis OA to the end of the effective area.

[0442] The fourth lens 404 and the fifth lens 405 can be cemented. The bonding surface between the fourth lens 404 and the fifth lens 405 can be defined as the eighth surface S8. The eighth surface S8 can be the same surface as the ninth surface S9 of the fifth lens 405. The object-side surface of the cemented lens 445 can be convex, and the sensor-side surface can be concave. The interval between the fourth lens 404 and the fifth lens 405 can be less than 0.01 mm and can be attached with an adhesive. The interval between the fourth lens 404 and the fifth lens 405 can be less than 0.01 mm from the optical axis OA to the end of the effective area. The fourth lens 404 and the fifth lens 405 can have opposite refractive powers. The compound refractive power of the fourth lens 404 and the fifth lens 405 can have a negative (-) refractive power.

[0443] A value of the radius of curvature of the cemented surface S8 of the cemented lens 445 can be greater than 90. For example, a value of the radius of curvature of the cemented surface S8 of the cemented lens 445 can be greater than 100. The cemented surface S8 of the cemented lens 445 can be formed in a gentle shape. Thereby, a cementing process of the fourth lens 404 and the fifth lens 405 forming the cemented lens 445 is advantageous, and a cementing retention strength can be increased.

[0444] A product of the refractive power of the object-side fourth lens 404 and the refractive power of the sensor-side fifth lens 405 of the cemented lens 445 can be less than 0. A product of the focal length of the object-side fourth lens 404 and the focal length of the sensor-side fifth lens 405 of the cemented lens 445 can be less than 0. Accordingly, an aberration characteristic of the optical system can be improved. If the refractive powers of the two lenses of the cemented lens 445 are the same, there is a limit to improvement in the aberration.

[0445] The composite refractive power of the cemented lens 445 has a negative (-) refractive power, and can have a negative (-) refractive power with respect to the third lens 403 on the object side and the sixth lens 406 on the sensor side of the cemented lens 445. Accordingly, the fourth lens 404, the cemented lens 445, and the fifth lens 405 can refract a portion of the incident light in the optical axis direction.

[0446] An effective diameter of the fourth lens 404 can be greater than a diagonal length of the image sensor 700. The effective diameter of the fourth lens 404 is an average of the effective diameters of the seventh surface S7 and the eighth surface S8, and can be greater than the diagonal length of the image sensor 700. An effective diameter of the fifth lens 405 can be less than the effective diameter of the fourth lens 404 and greater than the diagonal length of the image sensor 700. An effective diameter of the seventh surface S7 of the fourth lens 404 can be greater than the diagonal length of the image sensor 700, and an effective diameter of the tenth surface S10 of the fifth lens 405 can be less than the diagonal length of the image sensor 700.

[0447] When the fifth lens 405 is a spherical lens and the seventh lens 407 is an aspherical lens, a difference in effective diameter between the object side ninth surface S9 of the fifth lens 405 and the sensor side tenth surface S10 can be set to be the largest. For example, when the effective diameters of the ninth surface S9 and the sensor side tenth surface S10 of the fifth lens 405 are CA51 and CA52, a condition of CA51 > CA52 is satisfied, and a difference between CA51 and CA52 can be the largest among the differences in effective diameter between the object side surface and the sensor side surface of each lens. Accordingly, the difference in effective diameter between the object side surface and the sensor side surface of the fifth lens 405 can be set to be maximized in order to effectively guide light to travel through the aspherical lens having a relatively small effective diameter. Accordingly, a more slim optical system can be provided. The effective diameter of the fifth lens 405 can satisfy a condition of 1.1 < CA51 / CA52 < 1.5.

[0448] The cemented lens 445 is cemented with a glass lens having a different refractive index, has a spherical refractive surface, and at least one lens disposed closer to the sensor than the cemented lens 445 is an aspherical lens, so that spherical aberration can be compensated. In addition, at least one lens among the lenses disposed closer to the sensor than the cemented lens 445 is an aspherical lens and is disposed to have a small effective diameter, so that light can be effectively guided to travel through the aspherical lens to the image sensor 700. Since the cemented lens 445 is disposed between the aspherical lenses and between the spherical lenses, chromatic aberration correction can be more effective. By positioning the cemented lens 445 within the optical system, the TTL can be reduced.

[0449] The sixth lens 406 can be disposed as the sixth lens from the object side. The sixth lens 406 can be disposed as the second lens from the sensor side. The sixth lens 406 can be disposed between the fifth lens 405 and the seventh lens 407. The sixth lens 406 can have a positive (+) or negative (-) refractive power on the optical axis OA. The sixth lens 406 can have a positive (+) refractive power. The sixth lens 406 can include a plastic or a glass material. For example, the sixth lens 406 can be provided by a plastic material.

[0450] The sixth lens 406 can have a convex shape on the object side eleventh surface S11 and a concave shape on the sensor side twelfth surface S12 with respect to the optical axis. The sixth lens 406 can have a convex meniscus shape on the object side. At least one or both of the eleventh surface S11 and the twelfth surface S12 can be aspherical. Aspherical coefficients of the eleventh surface S11 and the twelfth surface S12 can be provided as Figure 41 L1 and L2 of L6 of

[0451] The eleventh surface S11 of the sixth lens 406 may be configured to have no critical point from the optical axis OA to the end of the effective area. The twelfth surface S12 of the sixth lens 406 may include a critical point from the optical axis OA to the end of the effective area. When the twelfth surface S12 has a critical point, it may be located within a range of 30% to 40% of the effective radius r62 from the optical axis OA, preferably within a range of 34% to 38% of the effective radius r62 from the optical axis OA. The critical point of the twelfth surface S12 may be located within a range of 1.3 mm to 1.8 mm from the optical axis OA, preferably within a range of 1.5 mm to 1.6 mm from the optical axis OA.

[0452] The seventh lens 407 may be positioned closest to the sensor. The seventh lens 407 may be positioned furthest from the object. The seventh lens 407 may have positive (+) or negative (-) refractive power along the optical axis OA. The seventh lens 407 may have negative (-) refractive power. The seventh lens 407 may be made of plastic or glass. For example, the seventh lens 407 may be made of plastic.

[0453] On the optical axis, the object-side thirteenth surface S13 of the seventh lens 407 may be convex, and the sensor-side fourteenth surface S14 may be concave. The seventh lens 407 may have a meniscus shape that is convex toward the object side. At least one of the thirteenth surface S13 and the fourteenth surface S14 may be an aspherical surface. For example, both the thirteenth surface S13 and the fourteenth surface S14 may be aspherical. The aspherical coefficients of the thirteenth surface S13 and the fourteenth surface S14 may be provided as Figure 41 S1 and S2 of L7.

[0454] The thirteenth surface S13 of the seventh lens element 407 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 within a range of 40% to 50% of the effective radius r71 from the optical axis OA, preferably within a range of 40% to 43% of the effective radius r71 from the optical axis OA. The critical point of the thirteenth surface S13 may be located within a range of 1.5 mm to 2.0 mm from the optical axis OA, preferably within a range of 1.6 mm to 1.7 mm from the optical axis OA. The thirteenth surface S13 having such a critical point can refract incident light toward the center and the edges, thereby improving aberrations.

[0455] The fourteenth surface S14 of the seventh lens 407 can have a critical point from the optical axis OA to the end of the effective region. When the fourteenth surface S14 has a critical point, it can be located in a range of 60% to 70% of the effective radius r72 from the optical axis OA, preferably in a range of 66% to 69% of the effective radius r72 from the optical axis OA. The critical point of the fourteenth surface S14 can be located in a range of 3 mm to 3.5 mm from the optical axis OA, preferably in a range of 3.0 mm to 3.1 mm from the optical axis OA.

[0456] The critical point of the thirteenth surface S13 and the fourteenth surface S14 is a point where the sign of the slope value with respect to the optical axis OA and a direction perpendicular to the optical axis OA changes from positive (+) to negative (-) or from negative (-) to positive (+), and can represent a point where the slope value is 0. In addition, the critical point of the thirteenth surface S13 and the fourteenth surface S14 can be a point where the slope value of the tangent line passing through the lens surface first increases and then decreases, or first decreases and then increases.

[0457] The seventh lens 407 can be a plastic lens closest to the image sensor 700. In addition, by arranging two or more plastic lenses adjacent to the image sensor 700, aberrations such as spherical aberration and chromatic aberration can be improved by the lens surface having an aspherical surface, and the influence on resolution can be controlled. In addition, by arranging a plastic lens as a lens adjacent to the image sensor 700, the plastic lens can be less sensitive to assembly tolerance than a glass lens. In other words, being less sensitive to assembly tolerance means that even if assembly is performed slightly differently than the design during assembly, the optical performance can not be significantly affected. In addition, by providing two lenses 406 and 407 adjacent to the image sensor 700 with plastic, the optical performance can be improved by the lens surface having an aspherical surface, and for example, aberration characteristics can be improved and degradation of resolution can be prevented.

[0458] The sixth lens 406 and the seventh lens 407 are disposed to be spaced apart from each other, but can include the characteristics of a cemented lens. The sixth lens 406 and the seventh lens 407 can have opposite refractive powers. The product of the refractive power of the sixth lens 406 and the refractive power of the seventh lens 407 can be less than 0. The product of the focal length of the sixth lens 406 and the focal length of the seventh lens 407 can be less than 0. Accordingly, the aberration characteristics of the optical system can be improved. If the signs of the refractive powers of the two lenses having the characteristics of a cemented lens are the same, there is a limit to the improvement in aberration.

[0459] The sixth lens 406 and the seventh lens 407 can be made of the same material. The sixth lens 406 and the seventh lens 407 can be made of a plastic material. The sixth lens 406 and the seventh lens 407 can be made of the same material as the cemented lens 445.

[0460] [Table 10]

[0461]

[0462]

[0463] Table 10 shows surface numbers (surfaces), radii of curvature (radii), center thicknesses of each lens or distances between lens surfaces (thicknesses), refractive indices (nd), Abbe numbers (vd), effective radii (half aperture diameters), and focal lengths (focal lengths) of lenses according to the fourth embodiment of the present application. At this time, units of the radii of curvature and the thicknesses or distances can be mm.

[0464] [Table 11]

[0465] Category Value Category Value F 14.7052 ET1 1.3802 F2_7 24.9373 ET2 6.7565 F3_7 17.0011 ET3 0.8976 F4_7 161.8800 ET4 1.2852 F5_7 -9.1945 ET5 4.6613 F6_7 45.8566 ET6 1.2581 F4_5 -113.8620 ET7 2.1002 ΣIndex 11.6521 F number 1.6096 ΣAbbe 313.5836 FOV_D 34.2549 ΣCT 19.63416 EPD 9.1359 ΣCG 5.89787 BFL 2.3680 CA_max 12.075 TD 25.5320 CA_min 8.400 ImgH 4.6300 CA_Aver 9.772 SD 16.0664 CT_max 6.1576 TTL 27.9000 CT_min 1.6943 GLca_Aver 10.305 CT_Aver 2.80488 PLca_Aver 8.4377 Image sensor 3840*2160

[0466] Table 11 shows categories of the above mathematical expressions in the optical system 1300 of the embodiment, including a total top length (TTL) (mm) of the optical system 1300, a back focal length (BFL), an effective focal length F (mm), ImgH (mm), an effective diameter CA (mm), a thickness (mm), a TTL (mm), TD (mm) which is an optical axis distance from the first surface S1 to the fourteenth surface S14, composite focal lengths F2_7, F3_7, F4_7, F5_7, F6_7, and F4_5 (mm) of the first lens to the seventh lens, a sum of refractive indices, a sum of Abbe numbers, a sum of thicknesses (mm), a sum of spacings between adjacent lenses, an effective diameter characteristic, a sum of refractive indices of glass lenses, a sum of refractive indices of plastic materials, a field of view angle FOV_H (degrees), an edge thickness ET, an F number, and the like.

[0467] As shown in Figure 40 and Figure 41 , center thicknesses of the first lens 401 to the seventh lens 407 are denoted by CT1 to CT7, edge thicknesses at ends of effective regions of each lens are denoted by ET1 to ET7, center spacings between two adjacent lenses are denoted by CG1 to CG6, and edge spacings between edges of each lens are denoted by EG1 to EG6. Here, a center thickness of the cemented lens 445 is CT45, and an edge thickness is denoted by ET45.

[0468] Referring to Figure 41 , a back focal length (BFL) is an optical axis distance from the image sensor 700 to a center of the last lens. In Figure 41 , a TTL is an optical axis distance from a center of the first surface S1 of the first lens 401 to an upper surface of the image sensor 700.

[0469] As shown in Figure 42As shown, among the lenses of the lens unit 400 in the fourth embodiment, the lens surfaces of the first lens 401, the sixth lens 406, and the seventh lens 407 may include aspheric surfaces having a 30th-order aspheric surface coefficient. For example, the first lens 401, the sixth lens 406, and the seventh lens 407 may include lens surfaces having a 30th-order aspheric surface coefficient. As described above, since an aspheric surface having a 30th-order aspheric surface coefficient (a value other than "0") can significantly change the aspheric shape of the peripheral portion, the optical performance of the peripheral portion of the field of view (FOV) can be well corrected.

[0470] like Figure 43 As shown, the thicknesses T1 to T7 of the first to seventh lenses 401, 402, 403, 404, 405, 406, and 407 and the intervals G1 to G6 between two adjacent lenses can be set. Figure 44 As shown, the thickness T1 to T7 of each lens in the Y-axis direction can be expressed at a pitch of 0.1 mm or 0.2 mm or more, and the pitch G1 to G6 between each lens can be expressed at a pitch of 0.1 mm or 0.2 mm or more.

[0471] When comparing the absolute values ​​of the radii of curvature of each lens, the sixth surface S6 of the third lens 403, along the optical axis OA, can have the largest radius of curvature among the lenses, and the tenth surface S10 of the fifth lens 405 can have the smallest radius of curvature among the lenses. The difference between the maximum and minimum radii of curvature can be 15 times or more, for example, 18 to 20 times. The sensor-side surface of the glass lens positioned on the object side of the plastic lens can have the smallest radius of curvature among the lenses. The sensor-side surface of the fifth lens 405, positioned on the object side of the sixth lens 406, can have the smallest radius of curvature among the lenses.

[0472] Since the effective diameter of the plastic lens is smaller than that of the glass lens, the lens disposed on the object side of the plastic lens can have a strong refractive power to refract light passing through the plastic lens. In addition, the curvature radius of the lens surface can be smaller to enhance the refractive power.

[0473] Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 10 mm or less among the object side surface and the sensor side surface can be two or less. The absolute value of the radius of curvature of the sensor side surface (the tenth surface) S10 of the fifth lens 405 can be 10 mm or less. Among the object side surface and the sensor side surface of the lenses, the number of surfaces of which the absolute value of the radius of curvature is 10 mm or more and 20 mm or less can be three or more and five or less. The absolute value of the radius of curvature of the object side surface (the third surface) S3 of the second lens 402, the object side surface (the seventh surface) S7 of the fourth lens 404, the object side surface (the eleventh surface) S11 of the sixth lens 406, and the sensor side surface (the fourteenth surface) S14 of the seventh lens 407 can be 10 mm or more and 20 mm or less. Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 60 mm or more among the object side surface and the sensor side surface can be at least one and not more than four. The absolute value of the radius of curvature of the object side surface (the first surface) S1 of the first lens 401, the sensor side surface (the eighth surface) S8 of the fourth lens 404, the object side surface (the ninth surface) S9 of the fifth lens 405, and the sensor side surface (the twelfth surface) S12 of the sixth lens 406 can be at least 60 mm.

[0474] In a temperature compensation design in which resolution needs to be maintained even when the temperature changes from -40 degrees to 100 degrees, a larger radius of curvature can be advantageous. In a design for temperature compensation, an aluminum lens barrel can be used as a lens barrel. The manufacturing tolerance of the aluminum lens barrel is large, and thus the misalignment of the optical axis of each lens is large when the lenses are assembled. Thus, by designing a larger radius of curvature, the sensitivity to the manufacturing tolerance can be reduced.

[0475] Reference Figure 45 The inclination angle of the lens surface can be expressed as a value in radians, which is the slope of the lens surface at a point having a 0.1 pitch with respect to the Y-axis perpendicular to the optical axis, converted into a tangent value. Regarding the inclination angle of the lens surface, the inclination angle of the object side surface (the first surface) S1 of the first lens 401 can be the smallest, excluding the cemented lens among the first to seventh lenses. Among the object side surfaces and the sensor side surfaces of the first to seventh lenses, the number of lenses having a value smaller than the absolute value of the inclination angle of the object side surface of the aspherical glass material can be five or less.

[0476] The shape of the first lens 401 having an aspherical shape can be designed to be flat. If the aspherical surface is located at the frontmost position in the optical system 1300, the performance of the lens is improved, but the assembly can be reduced. In order to improve the assembly, the shape of the first lens 401 should be designed to be flat. In order to minimize the influence on the lens disposed on the sensor side when the lens is assembled in the lens barrel, it can be designed to have little curvature.

[0477] With respect to the optical axis, when the center thickness of the lens is described, the center thickness CT2 of the second lens 402 is the largest among the lenses, and the center thickness CT7 of the seventh lens 407 is the smallest among the lenses. The difference between the largest center thickness and the smallest center thickness among the lenses can be in the range of 4.5 mm or more and 5.5 mm or less.

[0478] When the center spacing CG between the lenses is explained, the center spacing CG5 between the fifth lens 405 and the sixth lens 406 can be the largest, and the center spacing CG2 between the second lens 402 and the third lens 403 and the center spacing CG3 between the third lens 403 and the fourth lens 404 can be the smallest. Here, the smallest center spacing does not include the cemented surface of the cemented lens 445. The difference between the largest center spacing and the smallest center spacing among the spacings of the spaced lenses can be 1.5 mm or more, for example, in the range of 1.8 mm to 2.5 mm.

[0479] When the effective diameter is explained, the lens having the largest effective diameter can be disposed between the first lens 401 closest to the object and the seventh lens 407 closest to the image sensor 700. The lens having the largest effective diameter can be a glass lens. The lens having the largest effective diameter can be disposed between the first lens 401 and the cemented lens 445. The lens having the largest effective diameter can be the first lens 401. Here, the effective diameter is the average of the effective diameter of the object side surface and the effective diameter of the sensor side surface of each lens. The lens surface having the largest effective diameter can be the first surface S1 of the first lens 401.

[0480] The lens having the smallest effective diameter can be one of the cemented lenses or one of the plastic lenses, for example, the fifth lens 405 or the seventh lens 407 adjacent to the image sensor 700. For example, the effective diameter of the fifth lens 405 can be the smallest within the lens unit 400. The lens surface having the smallest effective diameter can be the tenth surface S10 of the fifth lens 405.

[0481] The effective diameter of each of the first lens 401 to the fourth lens 404 adjacent to the object side can be greater than the effective diameter of the fifth lens 405, the sixth lens 406, and the seventh lens 407 adjacent to the sensor side. The effective diameter of the first lens 401 to the fourth lens 404 can be greater than the diagonal length of the image sensor 700. The average effective diameter of the seventh lens 407 can be smaller than the diagonal length of the image sensor 700. Accordingly, light incident through the plurality of lenses arranged along the optical axis can be guided to the image sensor 700.

[0482] When the refractive index is explained, the refractive index of the fourth lens 404 can be the largest among the lenses, and can be greater than 1.78, for example, greater than 1.8. Either one or both of the third lens 403 and the sixth lens 406 can have the smallest refractive index among the lenses. For example, the refractive index of the sixth lens 406 can be the smallest among the lenses, and can be less than 1.6, for example, less than 1.55. The difference between the largest refractive index and the smallest refractive index can be 0.3 or more. By providing a high refractive index lens made of glass closest to the object, and providing the lens adjacent to the image sensor 700 and the lens adjacent to the glass lens with a low refractive index made of plastic, the incidence efficiency can be increased, and the refractive power between the glass lens and the plastic lens can be adjusted to guide the image sensor 700.

[0483] When the Abbe number is compared, the Abbe number of the third lens 403 is the largest among the lenses, and can be 70 or more. The Abbe number of the seventh lens 407 is the smallest among the lenses, and can be 25 or less. The difference between the largest refractive index and the smallest Abbe number can be 50 or more. By making the Abbe number of the third lens 403 adjacent to the cemented lens 445 the largest and making the Abbe number of the seventh lens 407 having a low refractive index adjacent to the image sensor 700 the smallest, 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 it to the image sensor 700.

[0484] The focal lengths F2, F5, and F7 of the second lens 402, the fifth lens 405, and the seventh lens 407 can have a negative (-) sign. The second lens 402, the fifth lens 405, and the seventh lens 407 can have a negative (-) refractive power. The focal lengths F1, F3, F4, and F6 of the first lens 401, the third lens 403, the fourth lens 404, and the sixth lens 406 can have a positive (+) sign. The first lens 401, the third lens 403, the fourth lens 404, and the sixth lens 406 can have a positive (+) refractive power. The third lens 403 and the fourth lens 404 having a positive (+) refractive power can be disposed on the sensor side of the second lens 402 having a negative (-) refractive power. Thereby, light incident on the object side can move away from the optical axis direction and then be gathered again in the optical axis direction, thereby forming a stable light path.

[0485] In addition, the sixth lens 406 and the seventh lens 407, which are adjacently disposed lenses, can satisfy the following conditions.

[0486] Condition 1: Refractive index of a lens having a positive refractive power < Refractive index of a lens having a negative refractive power

[0487] Here, among the plastic lenses, the sixth lens 406 has a positive refractive power and the seventh lens 407 has a negative refractive power, so that the refractive index of the sixth lens 406 is smaller than the refractive index of the seventh lens 407 and the dispersion value of the sixth lens 406 is larger than the dispersion value of the seventh lens 407 according to conditions 1 and 2. The chromatic aberration occurring in the plastic lenses can be corrected by the plastic lenses. Further, since the sixth lens 406 and the seventh lens 407 which are the plastic lenses arranged in series 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, the chromatic aberration occurring in the plastic lenses can be compensated by the plastic lenses.

[0488] The optical system has chromatic aberration, and the chromatic aberration is corrected by using a cemented lens or two lenses arranged in series. The lenses repeatedly contract and expand as the temperature changes from low temperature to high temperature. Since the lens characteristics of the lenses of the same material change the same amount according to the temperature change, the chromatic aberration between the lenses of the same material can be effectively corrected even if the temperature changes.

[0489] Therefore, in the fourth embodiment of the present application, the chromatic aberration occurring in the plastic lenses is corrected by using the cemented lens 445, the sixth lens 406, and the seventh lens 407.

[0490] The fourth lens 404 and the fifth lens 405 which are the cemented lenses can compensate for the chromatic aberration occurring in the glass lenses by satisfying 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. The refractive index difference is rounded to the third digit after the decimal point and the Abbe number difference is rounded to the first digit after the decimal point for numerical comparison.

[0491] When the focal lengths are compared in absolute values, the focal length of the first lens 401 is the largest among the lenses, and can be 50 or more and 60 or less. Among the lenses, the first lens 401 made of glass can have the largest focal length and the smallest refractive power. The focal length of the fifth lens 405 is the smallest among the lenses, and the absolute value of the focal length of the fifth lens 405 can be 5 or more and 10 or less. Among the lenses, the fifth lens 405 made of glass can have the smallest focal length and the largest refractive power. Since the lens made of a plastic material having a small refractive power is disposed on the sensor side of the fifth lens 405, the refractive power of the fifth lens 405 can be increased.

[0492] Among the lenses other than the cemented lens 445, the lens having the smallest focal length can be the sixth lens 406. The difference between the largest focal length and the smallest focal length can be 30 or more or 40 or more. Therefore, the optical system can have improved MTF characteristics, aberration control characteristics, resolution characteristics, and the like in a set angle of view range, and can have good optical performance in the edge portion of the angle of view.

[0493] The thickness T1 of the first lens 401 may have a difference of more than 1 times between its maximum and minimum thicknesses, for example, a difference in the range of 1 to 1.2 times, and the center thickness CT1 may be the largest, while the edge thickness ET1 may be the smallest. The thickness T2 of the second lens 402 may have a maximum thickness in the range of 1 to 1.2 times its minimum thickness. The second lens 402 may have a minimum center thickness CT2 and a maximum edge thickness ET2. The thickness T3 of the third lens 403 may be the largest at the center and smallest at the edge, and the maximum thickness may be in the range of 1.5 to 2 times the minimum thickness. The thickness T4 of the fourth lens 404 may be the largest at the center and smallest at the edge, and the maximum thickness may be in the range of 1.6 to 2.2 times the minimum thickness. The thickness T5 of the fifth lens 405 may be the smallest at the center and largest at the edge, and the maximum thickness may be in the range of 1.2 to 1.5 times the minimum thickness. The thickness T6 of the sixth lens 406 may be the largest at the center and smallest at the edge, and the maximum thickness may be in the range of 1 to 1.2 times the minimum thickness. A thickness T7 of the seventh lens 407 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.

[0494] The center thickness CT45 of the cemented lens 445 can be smaller than its edge thickness ET45. The center thickness CT45 of the cemented lens 445 is the distance from the center of the object-side seventh surface S7 of the fourth lens 404 to the center of the tenth surface S10 of the fifth lens 405. 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 cemented lens 445 can have a maximum thickness at the edge and a minimum thickness at the center, wherein the maximum thickness may be in the range of 1 to 1.2 times the minimum thickness.

[0495] Among the distances G1 to G6 between the lenses, the first distance G1 between the first lens 401 and the second lens 402 may have a maximum value in the center portion and a minimum value in the edge portion. The second distance G2 between the second and third lenses 402 and 403 may have a maximum value in the edge portion and a minimum value in the center portion. The third distance G3 between the third lens 403 and the fourth lens 404 may have a maximum value in the edge portion and a minimum value in the center portion. The fifth distance G5 between the fifth lens 405 and the sixth lens 406 may have a maximum value in the center portion and a minimum value in the edge portion. The sixth distance G6 between the sixth lens 406 and the seventh lens 407 may have a maximum value in the center portion and a minimum value in the edge portion.

[0496] like Figure 46 As shown, in Figure 40In the optical system and camera module of the present application, the chief ray angle (CRA) can be 10 degrees or more, for example, in the range of 10 degrees to 35 degrees or 10 degrees to 25 degrees, at 1 field of view which is the end of the diagonal length of the image sensor. 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.

[0497] Figures 47-49 is a graph showing the diffraction modulation transfer function (MTF) at room temperature, low temperature, and high temperature in the optical system of Figure 40 , and is a graph showing the modulation according to the spatial frequency. As shown in Figures 47-49 , in the fourth embodiment of the present application, the deviation of the MTF at low temperature or high temperature from room temperature can be less than 10%, i.e., 7% or less.

[0498] Figures 50-52 is a graph showing the aberration characteristics at room temperature, low temperature, and high temperature in the optical system of Figure 40 . In the aberration graph of Figures 50-52 , the spherical aberration (longitudinal spherical aberration), the astigmatism field curve, and the distortion are measured from left to right. In Figures 50-52 , the X axis can represent the focal length (mm) and the distortion degree (%), and the Y axis can represent the height of the image. In addition, the graph for the spherical aberration is a graph for light in the wavelength band of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for the astigmatism and distortion aberration is a graph for light in the wavelength band of about 546 nm. In Figures 50-52 the aberration graph, it can be explained that the closer each curve at room temperature, low temperature, and high temperature is to the Y axis, the better the aberration correction function. It can be seen that the optical system 1300 according to the fourth embodiment has a measured value close to the Y axis in almost all regions. That is, the optical system 1300 according to the fourth embodiment has improved resolution, and can have good optical performance not only in the center of the field of view (FOV) but also in the edge portion. Here, the low temperature is -20 degrees or less (for example, in the range of -20 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 more, for example, in the range of 85 degrees to 405 degrees. Therefore, it can be seen that Figures 50-52 the reduction in luminance ratio (modulation) from low temperature to high temperature in

[0499] Table 12 compares the changes in optical characteristics (such as EFL, BFL, F number (F#), TTL and field of view (FOV_H)) at room temperature, low temperature and high temperature in the optical system according to the fourth embodiment, and it can be seen that the rate of change of the optical characteristics at low temperature is less than 5% (for example, less than 3%) relative to room temperature, and it can be seen that the rate of change of the optical characteristics at low temperature is less than 5% (for example, less than 3%) relative to room temperature.

[0500] [Table 12]

[0501] Room temperature Low temperature High temperature Low temperature / Room temperature High temperature / Room temperature EFL(F) 14.7052 14.6513 14.7700 99.63％ 100.44％ BFL 0.0341 0.0360 0.0325 305.57％ 95.31％ F# 1.6096 1.6039 1.6164 99.65％ 100.42％ TTL 27.8600 27.8247 27.9016 99.87％ 100.15％ FOV_H 30.0001 30.1142 29.8667 100.38％ 99.56％

[0502] Therefore, as shown in Table 12, 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_H)) as the temperature changes from low to high temperatures is less than 10%, that is, less than 5%, for example, within the range of 0 to 5%. This makes it possible to design temperature compensation for plastic lenses even when using at least one or two or more plastic lenses, thereby preventing a decrease in the reliability of optical characteristics.

[0503] The optical system of the fourth 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).

[0504] An optical system according to a fifth embodiment of the present invention will be described.

[0505] Figure 53 is a side sectional view of an optical system and a camera module having the same according to a fifth embodiment; Figure 54 Is used to explain the Figure 53 A side sectional view showing the relationship between the n-th lens and the (n-1)-th lens; Figure 55 It shows Figure 53 Table of aspheric coefficients of lenses in optical systems; Figure 56 It shows Figure 53 A table showing the thickness of each lens and the spacing between adjacent lenses in the optical system; Figure 57 It shows Figure 53 a table of sag values ​​of lens surfaces of first to seventh lenses in the optical system; Figure 58 It shows Figure 53 a table of inclination angle values ​​of lens surfaces of first to seventh lenses in the optical system; Figure 59 It shows that according to Figure 53 The position of the image sensor in the optical system, and the table of chief ray angle (CRA) data at room temperature, low temperature and high temperature; Figures 60-62 Is to show aboutFigure 53 a graph of data of a diffraction modulation transfer function (MTF) of the optical system at room temperature, low temperature, and high temperature, and Figures 63-65 is a graph showing data of an aberration characteristic of the optical system at room temperature, low temperature, and high temperature. Figure 53

[0506] Referring to Figure 53 and Figure 54 , the optical system 1400 includes the lens unit 500, and the lens unit 500 can include first to seventh lenses 501 to 507. The first to seventh lenses 501 to 507 can be sequentially disposed along an optical axis OA of the optical system 1400. Light corresponding to object information can pass through the first to seventh lenses 501 to 507 and the optical filter 900 and be incident on the image sensor 700.

[0507] The first lens 501 can be disposed closest to an object side. The first lens 501 can be disposed farthest from a sensor side. The first lens 501 can have a negative (-) refractive power on the optical axis OA. The first lens 501 can include a plastic material or a glass material, and can be, for example, a glass material. The first lens 501 made of a glass material can reduce a change in a center position and a radius of curvature due to a temperature change according to a surrounding environment, and can protect an incident side surface of the optical system 1400.

[0508] A first surface S1 on an object side of the first lens 501 can be concave, and a second surface S2 on a sensor side can be convex with respect to the optical axis. The first lens 501 can have a meniscus shape convex toward the sensor side. The first lens 501 is made of glass and can have an aspherical surface. Aspherical coefficients of the first and second surfaces S1 and S2 can be provided as L1S1, L1S2 of Figure 55 The first lens 501 can be manufactured as a lens having an aspherical surface by injection molding of a glass material. The first lens 501 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 within a mold having an aspherical shape and through a heating and compression process.

[0509] ​The first lens 501 is provided by an aspherical glass material such that a glass material having a high transmittance and a refractive index has an aspherical surface, which can reduce the number of lenses in the optical system. The aspherical glass material can maintain optical performance at a constant level due to the glass material when the temperature becomes a low temperature or a high temperature. In addition, since the aspherical surface is applied to the glass material, the refractive index of light does not significantly change even if the lens is designed to be thin. Accordingly, unlike the optical system in which the first lens is designed to be the thickest in a horizontal viewing angle in the range of 30 to 50 degrees, the optical system of the present application can provide a thin first lens made of an aspherical glass material. Here, the thickness of the lens can include a center thickness and an edge thickness.

[0510] The refractive index n1 of the first lens 501 can satisfy a condition of n1>1.8 or n1>1.82. When the refractive index n1 of the first lens 501 satisfies the condition, the radii of curvature of the first lens 501 and the second lens 502 can be increased, and lens manufacturing can be facilitated. When the refractive index n1 of the first lens 501 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 501 and the second lens 502. In this case, lens manufacturing is not easy, the lens defect rate increases, and can cause a reduction in yield.

[0511] The second lens 502 can be disposed as the second from the object side. The second lens 502 can be disposed as the sixth from the sensor side. The second lens 502 can be disposed between the first lens 501 and the third lens 503. The second lens 502 can have a positive (+) refractive power on the optical axis OA. The second lens 502 can include a plastic or a glass material. For example, the second lens 502 can be provided by a glass material.

[0512] The object side third surface S3 of the second lens 502 can be convex, and the sensor side fourth surface S4 can be convex with respect to the optical axis OA. The second lens 502 can have a shape in which both surfaces are convex. The second lens 502 is made of glass and can be spherical. At least one or both of the third surface S3 and the fourth surface S4 can be spherical.

[0513] In addition, the second lens 502 can be further spaced apart from the third lens 503 due to the refractive characteristics of the second lens 502. That is, the center spacing between the second lens 502 and the third lens 503 can be the largest within the lens unit. In addition, that is, the edge spacing between the second lens 502 and the third lens 503 can be the largest within the lens unit.

[0514] Since the two surfaces of the second lens 502 are convexly disposed, the number of lenses and the TTL of the optical system can be minimized, and light can be effectively refracted. Further, when the radius of curvature of the third surface S3 of the second lens 502 is L2R1 and the radius of curvature of the fourth surface S4 is L2R2, the condition of L2R1>|L2R2| can be satisfied. Thereby, light can be effectively refracted by the third surface S3 so that the effective diameter of the third to seventh lenses 503 to 507 can be guided so as not to increase, and the TTL can be reduced. When L2R1<|L2R2|, many aberrations can occur on the object side surface of the second lens 502, the refractive efficiency of light at the sensor side surface can be reduced, the effective diameter of the rear lens can increase, and the TTL can also become larger.

[0515] An aperture stop can be disposed around the sensor side fourth surface S4 of the second lens 502. The aperture can reduce the TTL in the field of view range, and can miniaturize the optical system. Therefore, a reduction in yield due to the weight of the optical system can be prevented, and production efficiency can be improved. Further, by reducing the TTL in the horizontal field of view (FOV_H) of 25 degrees to 36 degrees, the optical system can be miniaturized.

[0516] The third lens 503 can be disposed as the third from the object side. The third lens 503 can be disposed as the fifth from the sensor side. The third lens 503 can be disposed between the second lens 502 and the fourth lens 504. The third lens 503 can have a positive (+) refractive power on the optical axis OA. The third lens 503 can include a plastic or a glass material. For example, the third lens 503 can be provided by a glass material.

[0517] The object side fifth surface S5 of the third lens 503 can be convex, and the sensor side sixth surface S6 can be concave with respect to the optical axis. The third lens 503 can have a meniscus shape convex on the object side on the optical axis OA. The third lens 503 is made of glass and can be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 can be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0518] The fourth lens 504 can be disposed as the fourth from the object side. The fourth lens 504 can be disposed as the fourth from the sensor side. The fourth lens 504 can be disposed between the third lens 503 and the fifth lens 505. The fourth lens 504 can have a positive (+) or negative (-) refractive power on the optical axis OA. The fourth lens 504 can have a positive (+) refractive power. The fourth lens 504 can have a positive (+) refractive power different from that of the fifth lens 505. The fourth lens 504 can include a plastic or a glass material. For example, the fourth lens 504 can be provided by a glass material. The fourth lens 504 can be provided by the same material as the fifth lens 505.

[0519] The object side seventh surface S7 of the fourth lens 504 can be convex, and the sensor side eighth surface S8 can be convex with respect to the optical axis. The fourth lens 504 can have a convex shape on both surfaces. The fourth lens 504 can be made of glass and can have a spherical surface. At least one or both of the seventh surface S7 and the eighth surface S8 can be spherical. The seventh surface S7 and the eighth surface S8 can be disposed without a critical point from the optical axis OA to the end of the effective area.

[0520] The fifth lens 505 can be disposed as the fifth from the object side. The fifth lens 505 can be disposed as the third from the sensor side. The fifth lens 505 can be disposed between the fourth lens 504 and the sixth lens 506. The fifth lens 505 can have a positive (+) or negative (-) refractive power on the optical axis OA. The fifth lens 505 can have a negative (-) refractive power. The fifth lens 505 can have a negative (-) refractive power different from that of the fourth lens 504. The fifth lens 505 can include a plastic or a glass material. For example, the fifth lens 505 can be provided by a glass material. The fifth lens 505 can be provided by the same material as the fourth lens 504.

[0521] The object side ninth surface S9 of the fifth lens 505 can be concave, and the sensor side tenth surface S10 can be concave with respect to the optical axis. The fifth lens 505 can have a shape in which both surfaces are concave. The fifth lens 505 is made of glass and can have a spherical surface. At least one of the ninth surface S9 and the tenth surface S10 can be a spherical surface. At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 505 can have no critical point from the optical axis OA to the end of the effective area.

[0522] The fourth lens 504 and the fifth lens 505 can be cemented. A bonding surface between the fourth lens 504 and the fifth lens 505 can be defined as an eighth surface S8. The eighth surface S8 can be the same surface as a ninth surface S9 of the fifth lens 505. An object side surface of the cemented lens 545 can be convex, and a sensor side surface can be concave. A spacing between the fourth lens 504 and the fifth lens 505 can be less than 0.01 mm, and can be attached with an adhesive. The spacing between the fourth lens 504 and the fifth lens 505 can be less than 0.01 mm from the optical axis OA to the end of the effective area. The fourth lens 504 and the fifth lens 505 can have opposite refractive powers. The composite refractive power of the fourth lens 504 and the fifth lens 505 can have a negative (-) refractive power.

[0523] A value of the radius of curvature of the cemented surface S8 of the cemented lens 545 can be less than 50. For example, the value of the radius of curvature of the cemented surface S8 of the cemented lens 545 can be less than 40. The cemented surface S8 of the cemented lens 545 can be formed in a gentle shape. Thereby, the cementing process of the fourth lens 504 and the fifth lens 505 forming the cemented lens 545 is advantageous, and the cementing retention strength can be increased.

[0524] A product of the refractive power of the object side fourth lens 504 and the refractive power of the sensor side fifth lens 505 of the cemented lens 545 can be less than 0. A product of the focal length of the object side fourth lens 505 and the focal length of the sensor side fifth lens 505 of the cemented lens 545 can be less than 0. Accordingly, the aberration characteristics of the optical system can be improved. When the refractive powers of the two lenses of the cemented lens 545 are the same, there is a limit to the improvement of the aberration.

[0525] The composite refractive power of the cemented lens 545 has a negative (-) refractive power, and can have a positive (+) refractive power with respect to the third lens 503 on the object side and the sixth lens 506 on the sensor side of the cemented lens 545. Accordingly, the fourth lens 504, the cemented lens 545, and the fifth lens 505 can refract a portion of the incident light in the optical axis direction.

[0526] An effective diameter of the fourth lens 504 can be greater than a diagonal length of the image sensor 700. The effective diameter of the fourth lens 504 is an average of the effective diameters of the seventh surface S7 and the eighth surface S8, and can be greater than the diagonal length of the image sensor 700. An effective diameter of the fifth lens 505 can be less than the effective diameter of the fourth lens 504 and greater than the diagonal length of the image sensor 700. An effective diameter of the seventh surface S7 of the fourth lens 504 can be greater than the diagonal length of the image sensor 700, and an effective diameter of the tenth surface S10 of the fifth lens 505 can be less than the diagonal length of the image sensor 700.

[0527] When the fifth lens 505 is a spherical lens and the seventh lens 507 is an aspherical lens, a difference in effective diameter between the object side ninth surface S9 of the fifth lens 505 and the sensor side tenth surface S10 can be set to be the largest. For example, when the effective diameters of the ninth surface S9 and the sensor side tenth surface S10 of the fifth lens 505 are CA51 and CA52, a condition of CA51>CA52 is satisfied, and a difference between CA51 and CA52 can be the largest among the differences in effective diameter between the object side surface and the sensor side surface of each lens. Accordingly, the difference in effective diameter between the object side surface and the sensor side surface of the fifth lens 505 can be set to be maximized in order to effectively guide light to travel through the aspherical lens having a relatively small effective diameter. Accordingly, a more slim optical system can be provided. The effective diameter of the fifth lens 505 can satisfy a condition of 1.1<CA51 / CA52<1.5.

[0528] The cemented lens 545 is cemented with a glass lens having a different refractive index, has a spherical refractive surface, and at least one lens disposed closer to the sensor than the cemented lens 545 is an aspherical lens, so that spherical aberration can be compensated. In addition, at least one lens among the lenses disposed closer to the sensor than the cemented lens 545 is an aspherical lens and is disposed to have a small effective diameter, so that light can be effectively guided to travel through the aspherical lens to the image sensor 700. Since the cemented lens 545 is disposed between the aspherical lenses and between the spherical lenses, chromatic aberration correction can be more effective. By positioning the cemented lens 545 within the optical system, the TTL can be reduced.

[0529] The sixth lens 506 can be disposed as the sixth lens from the object side. The sixth lens 506 can be disposed as the second lens from the sensor side. The sixth lens 506 can be disposed between the fifth lens 505 and the seventh lens 507. The sixth lens 506 can have a positive (+) or negative (-) refractive power on the optical axis OA. The sixth lens 506 can have a positive (+) refractive power. The sixth lens 506 can include a plastic or a glass material. For example, the sixth lens 506 can be provided by a plastic material.

[0530] The sixth lens 506 can have a convex shape on the object side eleventh surface S11 and a convex shape on the sensor side twelfth surface S12 with respect to the optical axis. The sixth lens 506 can have a convex shape on both surfaces on the optical axis OA. At least one or both of the eleventh surface S11 and the twelfth surface S12 can be aspherical. The aspherical coefficients of the eleventh surface S11 and the twelfth surface S12 can be provided as Figure 56 L1 and L2 of L6.

[0531] The eleventh surface S11 of the sixth lens 506 can be configured to have no critical point from the optical axis OA to the end of the effective region. The twelfth surface S12 can be configured to have at least one critical point from the optical axis OA to the end of the effective region.

[0532] The seventh lens 507 can be configured to be closest to the sensor side. The seventh lens 507 can be configured to be farthest from the object side. The seventh lens 507 can have a positive (+) or negative (-) refractive power on the optical axis OA. The seventh lens 507 can have a negative (-) refractive power. The seventh lens 507 can include a plastic or glass material. For example, the seventh lens 507 can be made of a plastic material.

[0533] On the optical axis, the object-side thirteenth surface S13 of the seventh lens 507 can be convex, and the sensor-side fourteenth surface S14 can be concave. The seventh lens 507 can have a meniscus shape convex toward the object side. At least one of the thirteenth surface S13 and the fourteenth surface S14 can be an aspheric surface. For example, both the thirteenth surface S13 and the fourteenth surface S14 can be aspheric. The aspheric coefficients of the thirteenth surface S13 and the fourteenth surface S14 can be provided as S1 and S2 of L7 in Equation 1. Figure 55

[0534] The thirteenth surface S13 of the seventh lens 507 can have a critical point from the optical axis OA to the end of the effective region. When the thirteenth surface S13 has a critical point, it can be located in a range of 30% to 40% of the effective radius r71 from the optical axis OA, preferably in a range of 34% to 37% of the effective radius r71 from the optical axis OA. The critical point of the thirteenth surface S13 can be located in a range of 1.3 mm to 1.7 mm from the optical axis OA, preferably in a range of 1.4 mm to 1.5 mm from the optical axis OA. The thirteenth surface S13 having such a critical point can refract incident light to the center portion and the edge portion, and improve aberration.

[0535] The fourteenth surface S14 of the seventh lens 507 can have a critical point from the optical axis OA to the end of the effective region. When the fourteenth surface S14 has a critical point, it can be located in a range of 65% to 75% of the effective radius r72 from the optical axis OA, preferably in a range of 68% to 71% of the effective radius r72 from the optical axis OA. The critical point of the fourteenth surface S14 can be located in a range of 3 mm to 3.3 mm from the optical axis OA, preferably in a range of 3.2 mm to 3.3 mm from the optical axis OA.

[0536] ​The critical point of the thirteenth surface S13 and the fourteenth surface S14 is a point at which the sign of the slope value with respect to the optical axis OA and a direction perpendicular to the optical axis OA changes from positive (+) to negative (-) or from negative (-) to positive (+), and can represent a point at which the slope value is 0. Further, the critical point of the thirteenth surface S13 and the fourteenth surface S14 can be a point at which the slope value of the tangent line passing through the lens surface first increases and then decreases, or first decreases and then increases.

[0537] The seventh lens 507 can be a plastic lens closest to the image sensor 700. Further, by arranging two or more plastic lenses adjacent to the image sensor 700, aberrations such as spherical aberration and chromatic aberration can be improved by the lens surface having an aspherical surface, and the influence on resolution can be controlled. Further, by arranging a plastic lens as a lens adjacent to the image sensor 700, the plastic lens can be less sensitive to assembly tolerance than a glass lens. In other words, being less sensitive to assembly tolerance means that even if assembly is performed slightly differently from the design during assembly, the optical performance can not be significantly affected. Further, by providing two lenses 506 and 507 adjacent to the image sensor 700 with plastic, the optical performance can be improved by the lens surface having an aspherical surface, and for example, aberration characteristics can be improved and degradation of resolution can be prevented.

[0538] The sixth lens 506 and the seventh lens 507 are disposed apart from each other, but can include the characteristics of a cemented lens. The sixth lens 506 and the seventh lens 507 can have opposite refractive powers. The product of the refractive power of the sixth lens 506 and the refractive power of the seventh lens 507 can be less than 0. The product of the focal length of the sixth lens 506 and the focal length of the seventh lens 507 can be less than 0. Accordingly, the aberration characteristics of the optical system can be improved. If the signs of the refractive powers of the two lenses having the characteristics of a cemented lens are the same, there is a limit to the improvement in aberration.

[0539] The sixth lens 506 and the seventh lens 507 can be made of the same material. The sixth lens 506 and the seventh lens 507 can be made of a plastic material. The sixth lens 506 and the seventh lens 507 can be made of the same material as the cemented lens 545.

[0540] [Table 13]

[0541]

[0542]

[0543]

[0544] Table 13 shows surface numbers (surfaces), radii of curvature (radii), center thicknesses of each lens or distances between lens surfaces (thicknesses), refractive indices (nd), Abbe numbers (vd), effective radii (half hole radii), and focal lengths (focal lengths) of lenses according to the fifth embodiment of the present application. At this time, units of the radii of curvature and the thicknesses or distances can be mm.

[0545] [Table 14]

[0546] Category Value Category Value F 14.7849 ET1 5.5267 F2_7 12.1170 ET2 0.9998 F3_7 21.2409 ET3 0.9076 F4_7 152.1520 ET4 1.4794 F5_7 -9.2571 ET5 4.3183 F6_7 81.8039 ET6 1.8333 F4_5 -451.3180 ET7 2.6561 ΣIndex 11.9895 F number 1.6046 ΣAbbe 291.5216 FOV_D 34.2163 ΣCT 19.13826 EPD 9.2143 ΣCG 7.41835 BFL 2.3434 CA_max 11.838 TD 26.5566 CA_min 8.670 ImgH 4.6300 CA_Aver 10.429 SD 19.6866 CT_max 5.1550 TTL 28.9000 CT_min 1.4150 GLca_Aver 11.049 CT_Aver 2.73404 PLca_Aver 8.8817 Image sensor 3840*2160

[0547] Table 14 shows categories of the above-described mathematical expressions in the optical system 1400 of the embodiment, including a total top length (TTL) (mm) of the optical system 1400, a back focal length (BFL), an effective focal length F (mm), ImgH (mm), an effective diameter CA (mm), a thickness (mm), a TTL (mm), TD (mm) which is an optical axis distance from the first surface S1 to the fourteenth surface S14, composite focal lengths F2_7, F3_7, F4_7, F5_7, F6_7, and F4_5 (mm) of the first lens to the seventh lens, a sum of refractive indices, a sum of Abbe numbers, a sum of thicknesses (mm), a sum of spacings between adjacent lenses, an effective diameter characteristic, a sum of refractive indices of glass lenses, a sum of refractive indices of plastic materials, a field of view angle FOV_H (degrees), an edge thickness ET, an F number, and the like.

[0548] As shown in Figure 53 and Figure 54 , center thicknesses of the first lens 501 to the seventh lens 507 are denoted by CT1 to CT7, edge thicknesses at ends of effective regions of each lens are denoted by ET1 to ET7, center spacings between two adjacent lenses are denoted by CG1 to CG6, and edge spacings between edges of each lens are denoted by EG1 to EG6. Here, the center thickness of the cemented lens 545 is CT45, and the edge thickness is denoted by ET45.

[0549] Referring to Figure 54 , the back focal length (BFL) is an optical axis distance from the image sensor 700 to the center of the last lens. In Figure 54 , the TTL is an optical axis distance from the center of the first surface S1 of the first lens 501 to the upper surface of the image sensor 700.

[0550] As shown in Figure 55As shown in the lens unit 500 in the fifth embodiment, the lens surfaces of the first lens 501, the sixth lens 506, and the seventh lens 507 can include an aspherical surface having a 30th order aspherical surface coefficient. For example, the first lens 501, the sixth lens 506, and the seventh lens 507 can include a lens surface having a 30th order aspherical surface coefficient. As described above, since the aspherical surface having a 30th order aspherical coefficient (a value other than "0") can significantly change the aspherical shape of the edge portion, the optical performance of the edge portion of the field of view (FOV) can be well corrected.

[0551] As Figure 56 shown, the thicknesses T1 to T7 of the first to seventh lenses 501, 502, 503, 504, 505, 506, and 507 and the intervals G1 to G6 between the adjacent two lenses can be set. As Figure 57 shown, the thicknesses T1 to T7 of each lens in the Y-axis direction can be expressed in an interval of 0.1 mm or more or 0.2 mm or more, and the intervals G1 to G6 between the lenses can be expressed in an interval of 0.1 mm or more or 0.2 mm or more.

[0552] When comparing the absolute values of the radii of curvature of each lens, the radius of curvature of the sixth surface S6 of the third lens 503 on the optical axis OA can be the largest among the lenses, and the radius of curvature of the tenth surface S10 of the fifth lens 505 can be the smallest among the lenses. The difference between the largest radius of curvature and the smallest radius of curvature can be 8 times or more, for example, 9 to 11 times. The radius of curvature of the sensor side surface of the glass material lens disposed on the object side of the plastic material lens can be the smallest among the lenses. The radius of curvature of the sensor side surface of the fifth lens 505 disposed on the object side of the sixth lens 506 can be the smallest among the lenses.

[0553] Since the effective diameter of the plastic lens is smaller than the effective diameter of the glass lens, the lens disposed on the object side of the plastic lens can have a strong refractive power to refract the light passing through the plastic lens. In addition, the radius of curvature of the lens surface can be small to enhance the refractive power.

[0554] Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 10 mm or less among the object side surface and the sensor side surface can be two or less. The absolute value of the radius of curvature of the sensor side surface (the tenth surface) S10 of the fifth lens 505 can be 10 mm or less. Among the object side surface and the sensor side surface of the lenses, the number of surfaces of which the absolute value of the radius of curvature is 10 mm or more and 20 mm or less can be three or more and five or less. The absolute value of the radius of curvature of the object side surface (the seventh surface) S7 of the fourth lens 404, the object side surface (the eleventh surface) S11 of the sixth lens 406, and the sensor side surface (the fourteenth surface) S14 of the seventh lens 407 can be 10 mm or more and 20 mm or less. Among the lenses, the number of surfaces of which the absolute value of the radius of curvature is 60 mm or more among the object side surface and the sensor side surface can be at least one and not more than four. The absolute value of the radius of curvature of the sensor side surface (the first surface) S1 of the first lens 501, the object side surface (the third surface) S3 of the second lens 502, and the sensor side surface (the sixth surface) S6 of the third lens 503 can be 60 mm or more.

[0555] In a temperature compensation design in which resolution needs to be maintained even when the temperature changes from -40 degrees to 100 degrees, a larger radius of curvature can be advantageous. In a design for temperature compensation, an aluminum lens barrel can be used as a lens barrel. The manufacturing tolerance of the aluminum lens barrel is large, and thus the misalignment of the optical axis of each lens is large when the lenses are assembled. Thus, by designing a larger radius of curvature, the sensitivity to the manufacturing tolerance can be reduced.

[0556] Reference Figure 58 The inclination angle of the lens surface can be expressed as a value in radians, which is the slope of the lens surface at a point having a 0.1 pitch with respect to the Y-axis perpendicular to the optical axis, converted into a tangent value. Regarding the inclination angle of the lens surface, the inclination angle of the object side surface (the first surface) S1 of the first lens 501 can be the smallest, excluding the cemented lens among the first to seventh lenses. Among the object side surface and the sensor side surface of the first to seventh lenses, the number of lenses having a value smaller than the absolute value of the inclination angle of the lens surface of the object side surface of the aspherical glass material can be five or less. Preferably, the number of lenses smaller than the absolute value of the inclination angle of the object side surface (the first surface) S1 of the first lens 501 can be four. The absolute value of the inclination angle of the object side surface (the third surface) S3 and the sensor side surface (the fourth surface) S4 of the second lens 502, the sensor side surface (the sixth surface) S6 of the third lens 503, the sensor side surface (the eighth surface) S8 of the fourth lens 504, and the object side surface (the ninth surface) S9 of the fifth lens 505 can be smaller than the absolute value of the inclination angle of the object side surface (the first surface) S1 of the first lens 501.

[0557] The shape of the first lens 501 having an aspherical shape can be designed to be flat. If the aspherical surface is located at the frontmost in the optical system 1400, the performance of the lens is improved, but the assembly property can be degraded. To improve the assembly property, the shape of the first lens 501 should be designed to be flat. To minimize the influence on the lens disposed on the sensor side when the lens is assembled in the lens barrel, it can be designed to have almost no curvature.

[0558] With respect to the optical axis, when the center thickness of the lens is described, the center thickness CT3 of the first lens 501 is the largest among the lenses, and the center thickness CT2 of the second lens 502 is the smallest among the lenses. The difference between the largest center thickness and the smallest center thickness among the lenses can be in the range of 3.5 mm or more and 5.5 mm or less.

[0559] When explaining the center spacing CG between the lenses, the center spacing CG2 between the second lens 502 and the third lens 503 can be the largest, and the center spacing CG1 between the first lens 501 and the second lens 502 and the center spacing CG3 between the third lens 503 and the fourth lens 504 can be the smallest. Here, the smallest center spacing does not include the cemented surface of the cemented lens 545. The difference between the largest center spacing and the smallest center spacing among the spacings of the lenses spaced apart can be 3.0 mm or more, for example, in the range of 3.0 mm to 3.5 mm.

[0560] When explaining the effective diameter, the lens having the largest effective diameter can be disposed between the first lens 501 closest to the object and the seventh lens 507 closest to the image sensor 700. The lens having the largest effective diameter can be a glass lens. The lens having the largest effective diameter can be disposed between the first lens 501 and the cemented lens 545. The lens having the largest effective diameter can be the third lens 503. Here, the effective diameter is the average of the effective diameter of the object side surface and the effective diameter of the sensor side surface of each lens. The lens surface having the largest effective diameter can be the seventh surface S7 of the fourth lens 504.

[0561] The lens having the smallest effective diameter can be one of the cemented lens or one of the plastic material lens, for example, the fifth lens 505 or the seventh lens 507 adjacent to the image sensor 700. For example, the effective diameter of the seventh lens 507 can be the smallest of the lens unit 500. The lens surface having the smallest effective diameter can be the thirteenth surface S13 of the seventh lens 507. The effective diameter of the plastic material lens can be smaller than the effective diameter of the glass material lens. The plastic material lens can be disposed adjacent to the image sensor.

[0562] An effective diameter of each of the first to fifth lenses 501 to 505 adjacent to the object side can be greater than effective diameters of the sixth and seventh lenses 506 and 507 adjacent to the sensor side. The effective diameters of the first to fifth lenses 501 to 505 can be greater than a diagonal length of the image sensor 700. The average effective diameters of the sixth and seventh lenses 506 and 507 can be less than the diagonal length of the image sensor 700. Accordingly, light incident through the plurality of lenses arranged along the optical axis can be guided to the image sensor 700.

[0563] When the refractive indices are explained, the refractive index of the third lens 503 can be the greatest among the lenses, and can be greater than 1.8, for example, greater than 1.82. Either or both of the third lens 503 and the sixth lens 506 can have the smallest refractive index among the lenses. For example, the refractive index of the sixth lens 506 can be the smallest among the lenses, and can be less than 1.6, for example, less than 1.55. The difference between the greatest refractive index and the smallest refractive index can be 0.2 or more. By providing a high refractive index lens made of glass closest to the object, and providing the lens adjacent to the image sensor 700 and the lens adjacent to the glass lens with a low refractive index made of plastic, the incidence efficiency can be increased, and the refractive power between the lenses made of glass and plastic can be adjusted to guide it to the image sensor 700.

[0564] When the Abbe numbers are compared, the Abbe number of the third lens 503 is the greatest among the lenses, and can be 70 or more. The Abbe number of the seventh lens 507 is the smallest among the lenses, and can be 25 or less. The difference between the greatest refractive index and the smallest Abbe number can be 50 or more. By making the Abbe number of the third lens 503 adjacent to the cemented lens 545 the greatest and making the Abbe number of the seventh lens 507 having a low refractive index adjacent to the image sensor 700 the smallest, 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 it to the image sensor 700.

[0565] The focal lengths F1, F5, and F7 of the first lens 501, the fifth lens 505, and the seventh lens 507 can have a negative (-) sign. The first lens 501, the fifth lens 505, and the seventh lens 507 can have a negative (-) refractive power. The focal lengths F2, F3, F4, and F6 of the second lens 502, the third lens 503, the fourth lens 504, and the sixth lens 506 can have a positive (+) sign. The second lens 502, the third lens 503, the fourth lens 504, and the sixth lens 506 can have a positive (+) refractive power. The second lens 502, the third lens 503, and the fourth lens 504 having a positive (+) refractive power can be disposed on the sensor side of the first lens 501 having a negative (-) refractive power. Thereby, light incident on the object side can move away from the optical axis direction and then be gathered again in the optical axis direction, thereby forming a stable light path.

[0566] Further, the sixth lens 506 and the seventh lens 507, which are adjacently disposed lenses, can satisfy the following conditions.

[0567] Condition 1: refractive index of a lens having a positive refractive power < refractive index of a lens having a negative refractive power

[0568] Here, among the plastic lenses, the sixth lens 506 has a positive refractive power and the seventh lens 507 has a negative refractive power, such that according to the conditions 1 and 2, the refractive index of the sixth lens 506 is smaller than that of the seventh lens 507, and the dispersion value of the sixth lens 506 is greater than that of the seventh lens 507. The chromatic aberration occurring in the plastic lenses can be corrected by the plastic lenses. Further, since the sixth lens 506 and the seventh lens 507, which are adjacently disposed plastic lenses, 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, the chromatic aberration occurring in the plastic lenses can be compensated for by the plastic lenses.

[0569] An optical system has chromatic aberration, and the chromatic aberration is corrected by using a cemented lens or two lenses adjacently disposed. As the temperature changes from low to high, the lenses repeatedly shrink and expand. Since the lens characteristics of lenses of the same material change by the same amount according to the temperature change, the chromatic aberration between the lenses of the same material can be effectively corrected even if the temperature changes.

[0570] Therefore, in the fifth embodiment of the present application, the chromatic aberration occurring in the plastic lenses is corrected by using the cemented lens 545, the sixth lens 506, and the seventh lens 507.

[0571] The fourth lens 504 and the fifth lens 505, which are cemented lenses, can compensate for chromatic aberration occurring in a glass lens by satisfying 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. The refractive index difference is rounded to the third digit after the decimal point, and the Abbe number difference is rounded to the first digit after the decimal point for numerical comparison.

[0572] When the focal lengths are compared in absolute values, the focal length of the first lens 501 is the largest among the lenses, and can be 50 or more and 80 or less. Among the lenses, the first lens 501 made of glass can have the largest focal length and the smallest refractive power. The focal length of the fifth lens 505 is the smallest among the lenses, and the absolute value of the focal length of the fifth lens 505 can be 5 or more and 10 or less. Among the lenses, the fifth lens 505 made of glass can have the smallest focal length and the largest refractive power. Since a lens made of a plastic material having a small refractive power is disposed on the sensor side of the fifth lens 505, the refractive power of the fifth lens 505 can be increased.

[0573] Among the lenses other than the cemented lens 545, the lens having the smallest focal length can be the sixth lens 506. The difference between the largest focal length and the smallest focal length can be 30 or more or 40 or more. Thus, the optical system can have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. in a set view angle range, and can have good optical performance in an edge portion of the view angle.

[0574] The thickness T1 of the first lens 501 can be a difference of 1 times or more between the largest thickness and the smallest thickness, for example, a difference in the range of 1 to 1.2 times, and the central thickness CT1 can be the smallest, and the edge thickness ET1 can be the largest. The thickness T2 of the second lens 502 can be the largest thickness in the range of 1.2 to 1.5 times the smallest thickness. The second lens 502 can have the smallest central thickness CT2 and the largest edge thickness ET2. The thickness T3 of the third lens 503 can be the largest at the center and the smallest at the edge, and the largest thickness can be in the range of 1.5 to 2 times the smallest thickness. The thickness T4 of the fourth lens 504 can be the largest at the center and the smallest at the edge, and the largest thickness can be in the range of 2.4 to 2.6 times the smallest thickness. The thickness T5 of the fifth lens 505 can be the smallest at the center and the largest at the edge, and the largest thickness can be in the range of 1.4 to 1.6 times the smallest thickness. The thickness T6 of the sixth lens 506 can be the largest at the center and the smallest at the edge, and the largest thickness can be in the range of 1.4 to 1.6 times the smallest thickness. The thickness T7 of the seventh lens 507 can be the smallest at the center and the largest at the edge, and the largest thickness can be in the range of 1.1 to 1.4 times the smallest thickness.

[0575] The center thickness CT45 of the cemented lens 545 may be greater than its edge thickness ET45. The center thickness CT45 of the cemented lens 545 is the distance from the center of the object-side seventh surface S7 of the fourth lens 504 to the center of the tenth surface S10 of the fifth lens 505. 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 cemented lens 545 may have a maximum thickness at the center and a minimum thickness at the edge, wherein the maximum thickness may be in the range of 1 to 1.2 times the minimum thickness.

[0576] Among the spacings G1 to G6 between the lenses, the first spacing G1 between the first lens 501 and the second lens 502 may have a maximum value in the edge portion and a minimum value in the center portion. The second spacing G2 between the second lens 502 and the third lens 503 may have a maximum value in the edge portion and a minimum value in the center portion. The third spacing G3 between the third lens 503 and the fourth lens 504 may have a maximum value in the edge portion and a minimum value in the center portion. The fifth spacing G5 between the fifth lens 505 and the sixth lens 506 may have a maximum value in the center portion and a minimum value in the edge portion. The sixth spacing G6 between the sixth lens 506 and the seventh lens 507 may have a maximum value in the center portion and a minimum value in the edge portion.

[0577] like Figure 59 As shown, in Figure 53 In an optical system and camera module, the chief ray angle (CRA) at a field of view (FOV) of 1°, which is the end of the diagonal length of the image sensor, can be 10 degrees or greater, for example, within a range of 10 to 35 degrees or 10 to 25 degrees. Furthermore, the difference in the chief ray angle from a low temperature (-40 degrees) to a high temperature (95 degrees) can be 1 degree or less. Therefore, even if the temperature changes from low to high, the difference in the chief ray angle is minimal, achieving stable optical performance.

[0578] Figures 60-62 It shows Figure 53 Graphs of diffraction modulation transfer functions (MTFs) at room temperature, low temperature, and high temperature in an optical system of FIG. 1 are graphs showing modulation according to spatial frequency. Figures 60-62 As shown, in the fifth embodiment of the present invention, the deviation of the MTF at low or high temperature based on the room temperature can be less than 10%, that is, less than 7%.

[0579] Figures 63-65 It shows Figure 53 The aberration characteristics of the optical system at room temperature, low temperature and high temperature are shown in the graph. Figures 63-65In the aberration graph, from left to right, the spherical aberration (longitudinal spherical aberration), the astigmatism field curve, and the distortion are measured. In the aberration graph, Figures 63-65 In the aberration graph, the X-axis can represent the focal length (mm) and the distortion degree (%), and the Y-axis can represent the height of the image. Further, the graph for the spherical aberration is a graph for light in the wavelength band of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for the astigmatism and distortion aberration is a graph for light in the wavelength band of about 546 nm. In the aberration graph, Figures 63-65 In the aberration graph, it can be explained that the closer each curve at room temperature, low temperature, and high temperature to the Y-axis, the better the aberration correction function. It can be seen that the optical system 1400 according to the fifth embodiment has a measurement value close to the Y-axis in almost all regions. That is, the optical system 1400 according to the fifth embodiment has improved resolution, and can have good optical performance not only in the center of the field of view (FOV) but also in the edge portion. Here, the low temperature is -20 degrees or lower (for example, in the range of -20 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 505 degrees). Therefore, it can be seen that Figures 63-65 In the aberration graph, the decrease in the luminance ratio (modulation) from the low temperature to the high temperature is less than 10%, for example, 5% or less, or almost no change.

[0580] Table 15 compares the changes in the optical characteristics (such as EFL, BFL, F number (F#), TTL, and field of view (FOV_H)) at room temperature, low temperature, and high temperature in the optical system according to the fifth embodiment, and it can be seen that the change rate of the optical characteristics at the low temperature is 5% or less (for example, 3% or less) relative to the room te...

Claims

1. An optical system comprising: The first to seventh lenses are arranged along the optical axis. The first lens has positive (+) or negative (-) refractive power. The second lens has positive (+) or negative (-) refractive power. Among them, the third lens has positive (+) refractive power, Among them, the fourth lens has positive (+) refractive power, Among them, the fifth lens has negative (-) refractive power, Among them, the sixth lens has positive (+) refractive power, Among them, the seventh lens has negative (-) refractive power, wherein the sixth lens and the seventh lens are plastic lenses, and Among the first to seventh lenses, the sensor-side surface of the fifth lens has the smallest curvature radius.

2. The optical system according to claim 1, in, Among the first to seventh lenses, the fifth lens has the shortest focal length.

3. The optical system according to claim 1, in, The fifth lens is a lens disposed adjacent to the object side of the plastic lens, and Among the first to seventh lenses, the effective diameter of the sensor-side surface of the fifth lens is the smallest.

4. The optical system according to claim 1, in, On the optical axis, a distance between two adjacent lenses among the first to seventh lenses is a maximum distance between the fifth lens and the sixth lens.

5. The optical system according to claim 1, in, The optical system includes a cemented lens, and Among them, except for the cemented lens surface of the cemented lens, there is one or less surface among the object-side surfaces and sensor-side surfaces of the first to seventh lenses on the optical axis having a curvature radius greater than the curvature radius of the object-side surface of the first lens.

6. An optical system comprising: The first to seventh lenses are arranged along the optical axis. The first lens has positive (+) or negative (-) refractive power. The second lens has positive (+) or negative (-) refractive power. Among them, the third lens has positive (+) refractive power, Among them, the fourth lens has positive (+) refractive power, Among them, the fifth lens has negative (-) refractive power, Among them, the sixth lens has positive (+) refractive power, Among them, the seventh lens has negative (-) refractive power, Wherein, the fourth lens and the fifth lens are cemented lenses, wherein, among the maximum values ​​of the absolute values ​​of the inclination angles of the object-side surface and the sensor-side surface of each of the first to seventh lenses, excluding the cemented surface of each of the cemented lenses, the maximum value of the absolute value of the inclination angle of the object-side surface of the first lens is the smallest, and The tilt angle is the normal slope at any point on the lens surface.

7. The optical system according to claim 6, in, Among the first to seventh lenses, a difference between a sag value of an object-side surface of the first lens on the optical axis and a maximum sag value of the object-side surface of the first lens is smallest.

8. An optical system comprising: The first to seventh lenses are arranged along the optical axis. Among them, the third lens has positive (+) refractive power, Among them, the fourth lens has positive (+) refractive power, Among them, the fifth lens has negative (-) refractive power, Among them, the sixth lens has a positive (+) refractive power, Among them, the seventh lens has a negative (-) refractive power, Among them, the fourth lens and the fifth lens are cemented lenses, Among the first lens to the seventh lens, the effective diameter of the first lens is the largest, Among them, the optical system satisfies the conditional expression 1.2 < CAL1 / ImgH < 1.5, and Among them, CAL1 is the size of the effective diameter of the first lens, and ImgH is 1 / 2 of the maximum diagonal length of the image sensor on the optical axis.

9. The optical system according to claim 8, in, Among the object-side surfaces and the sensor-side surfaces of the first lens to the seventh lens, the radius of curvature of four or fewer lens surfaces is greater than 60 mm.

10. The optical system according to claim 8, in, Among the object-side surfaces and the sensor-side surfaces of the first lens to the seventh lens, the radius of curvature of four or more but not more than five lens surfaces is less than 20 mm.

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