Optical system and imaging device module

Abstract

An optical system according to an embodiment of the present invention includes first to seventh lenses arranged along an optical axis, wherein: the first lens has a negative (-) refractive power; the second lens has negative (-) refractive power; a third lens having positive (+) refractive power; a fourth lens having positive (+) refractive power; a fifth lens having negative (-) refractive power; a sixth lens having positive (+) refractive power; a seventh lens having negative (-) refractive power; a diaphragm is arranged between the second lens and the third lens; among the first to seventh lenses, the third lens has a maximum thickness on the optical axis.

Description

Technical Field

[0001] Teachings according to exemplary and non-limiting embodiments of the present invention generally relate to an optical system for improving optical performance and a camera module including the optical system. Background Art

[0002] ADAS (Advanced Driver Assistance System) is an advanced driver assistance system designed to assist the driver in driving. It consists of sensing the situation ahead, judging the situation based on the sensing results, and controlling the vehicle's behavior based on the situation judgment. For example, an ADAS sensor device detects the vehicle ahead and identifies the lane. Once the target lane, target speed or forward target are determined, systems such as the vehicle's ESC (Electronic Stability Control), EMS (Engine Management System) and MDPS (Motor Driven Power Steering) are controlled. Generally, ADAS can be implemented in various forms including automatic parking systems, low-speed city driving assistance systems and blind spot warning systems.

[0003] Sensors used in ADAS to detect forward conditions include GPS sensors, laser scanners, front radars, and lidars. The most representative of these are cameras that capture images of the front, rear, and sides of the vehicle.

[0004] Such cameras can be placed outside or inside a vehicle to monitor the vehicle's surroundings. Furthermore, cameras can be placed inside a vehicle to monitor the condition of the driver and passengers. For example, a camera can capture the driver from a position close to the driver and monitor the driver's health, sleepiness, or intoxication. Furthermore, a camera can capture passengers from a position close to the driver to monitor their sleepiness and health, and provide information about the passengers to the driver.

[0005] In particular, the most important element for capturing images from an imaging device is the imaging lens that forms the image. Recently, interest in high-performance features such as high definition and resolution has grown, and research is underway into optical systems that incorporate multiple lenses to achieve these features. However, when an imaging device is exposed to harsh environments inside or outside a vehicle, such as high temperatures, low temperatures, moisture, or high humidity, the characteristics of the optical system may change. In such situations, achieving consistently excellent optical and aberration characteristics can be difficult.

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

[0007]

Technical Topics

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

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

[0010] Embodiments are directed to providing an optical system and a camera module that can prevent or minimize changes in optical characteristics within a wide temperature range.

[0011]

Technical Solution

[0012] In order to solve the above technical subject, an optical system according to an embodiment of the present invention may include first to seventh lenses arranged along the optical axis, wherein: the first lens has negative (-) refractive power; the second lens has 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; an aperture (stop) is set between the second lens and the third lens; and among the first to seventh lenses, the third lens has the largest thickness on the optical axis.

[0013] Preferably, but not necessarily, at least one of the first lens and the third lens may be made of glass, and at least one of the second lens and the fourth to seventh lenses may be made of plastic.

[0014] Preferably, but not necessarily, on the optical axis, the sixth lens may have a convex shape on both surfaces, and on the optical axis, the seventh lens may have a meniscus shape that is convex toward the object side.

[0015] Preferably, but not necessarily, among the first to seventh lenses, the absolute value of the focal length of the first lens may be the largest.

[0016] Preferably, but not necessarily, from the optical axis to the effective diameter area, the maximum distance between two lenses having the largest Abbe number difference among adjacent lenses may be smaller than the maximum distance between the other two adjacent lenses.

[0017] Preferably, but not necessarily, the fourth lens and the fifth lens may have the largest Abbe number difference among adjacent lenses.

[0018] Preferably, but not necessarily, the following conditions may be satisfied.

[0019] <Condition> 40<FOV_H<60

[0020] (In this condition, FOV_H refers to the horizontal field of view (horizontality) of the optical system.)

[0021] Preferably, but not necessarily, the following conditions may be satisfied.

[0022] <Condition> 0.31 < CG1 / ΣCG < 0.5

[0023] (In this condition, CG1 is the distance between the first lens and the second lens on the optical axis, and ΣCG is the sum of the gaps between adjacent lenses on the optical axis.)

[0024] Preferably, but not necessarily, the following conditions may be satisfied.

[0025] <Condition> 5 <TTL / ImgH <7

[0026] (In this condition, TTL is the distance from the vertex of the object-side surface of the first lens to the image surface of the image sensor along the optical axis, and ImgH is 1 / 2 of the maximum diagonal length of the image sensor.)

[0027] In order to solve the above-mentioned technical subject, an optical system according to an embodiment of the present invention may include first to seventh lenses arranged along an optical axis, wherein: the second lens has 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; and the effective diameter of the second lens is the smallest among the first to seventh lenses, and the effective diameter of the fourth lens is the largest among the first to seventh lenses.

[0028] Preferably, but not necessarily, the distance between the first lens and the second lens may be the largest among the distances between adjacent lenses on the optical axis.

[0029] Preferably, but not necessarily, an aperture may be provided between the second lens and the third lens, and the optical system may include a first lens group provided on the object side relative to the aperture and a second lens group provided on the sensor side relative to the aperture, wherein the sign of the composite focal length of the first lens group may be different from the sign of the composite focal length of the second lens group.

[0030] Preferably, but not necessarily, at least one of the lenses provided on the object side and the sensor side of the aperture may be made of a glass material.

[0031] Preferably, but not necessarily, the absolute value of the focal length of the first lens may be the largest among the first to seventh lenses.

[0032] Preferably, but not necessarily, the following conditions may be satisfied.

[0033] <Condition> 3 <ΣCT / ΣCG < 4

[0034] (In this condition, ΣCT means the sum of the center thicknesses of the first to seventh lenses on the optical axis, and ΣCG means the sum of the gaps between adjacent lenses on the optical axis.)

[0035] Beneficial effects

[0036] The optical system and camera module according to embodiments can have improved optical characteristics. More specifically, in the optical system according to embodiments, multiple lenses can have a predetermined thickness, refractive power, and spacing from adjacent lenses. Consequently, the optical system and camera module according to embodiments can have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. within a predetermined field of view, and can exhibit good optical performance in the peripheral areas of the field of view.

[0037] In addition, the optical system and the camera module according to the embodiment can have good optical performance in a low temperature to high temperature range (-40°C to 105°C). More specifically, the multiple lenses included in the optical system can have predetermined materials, refractive indices and refractive powers. Therefore, when the refractive index of each lens changes due to temperature changes, and therefore the focal length of each lens changes, the plastic lens and the glass lens can compensate for each other. In other words, the optical system can effectively distribute the refractive power across the low temperature to high temperature range and prevent or minimize changes in optical characteristics within this range. Therefore, the optical system and the camera module according to the embodiment can maintain improved optical characteristics across a wide temperature range.

[0038] Furthermore, the optical system and camera module according to the embodiments can achieve a desired viewing angle and excellent optical characteristics through a combination of plastic and glass lenses. Consequently, the optical system can provide a thinner vehicle camera module. Consequently, the optical system and camera module can be used in a variety of applications and devices, and maintain excellent optical characteristics even under harsh temperature conditions, such as when exposed to high temperatures outside or inside a vehicle during the summer. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a side sectional view of an optical system and an image pickup device module including the optical system according to the first embodiment.

[0040] Figure 2 It shows Figure 1 A table of aspheric coefficients of lenses in an optical system.

[0041] Figure 3 It shows Figure 1 A table showing the thickness of each lens in an optical system and the gaps between adjacent lenses.

[0042] Figure 4 It shows Figure 1 A table showing sag values ​​of lens surfaces of the first to seventh lenses in the optical system.

[0043] Figure 5 It shows Figure 1 A table showing inclination angle values ​​of the lens surfaces of the first lens to the seventh lens in the optical system.

[0044] Figure 6 It shows Figure 1 A graph showing the diffraction MTF (Modulation Transfer Function) data of an optical system at room temperature.

[0045] Figure 7 It shows Figure 1 A graph showing the aberration characteristics of an optical system at room temperature.

[0046] Figure 8 It shows Figure 1 The following is a graph of the diffraction MTF data of the optical system at low temperatures.

[0047] Figure 9 It shows Figure 1 The graph shows the aberration characteristic data of the optical system at low temperatures.

[0048] Figure 10 It shows Figure 1 Shown is a graph of diffraction MTF data for an optical system at high temperature.

[0049] Figure 11 It shows Figure 1 The graph shows the aberration characteristic data of the optical system at high temperature.

[0050] Figure 12 It shows Figure 1 A graph showing the peripheral light intensity ratio of the optical system shown.

[0051] Figure 13 is a side sectional view of an optical system and an image pickup device module including the optical system according to a second embodiment.

[0052] Figure 14 It shows Figure 13 A table of aspheric coefficients of lenses in an optical system.

[0053] Figure 15 It shows Figure 13 A table showing the thickness of each lens in an optical system and the gaps between adjacent lenses.

[0054] Figure 16 It shows Figure 13A table showing sag values ​​of the lens surfaces of the first to seventh lenses in the optical system.

[0055] Figure 17 It shows Figure 13 Table of the inclination angles of the lens surfaces of the first to seventh lenses in the optical system.

[0056] Figure 18 It shows Figure 13 The shown optical system is a graph of data on diffraction MTF (Modulation Transfer Function) at room temperature.

[0057] Figure 19 It shows Figure 13 This is a graph showing data on aberration characteristics of the optical system at room temperature.

[0058] Figure 20 It shows Figure 13 A graph showing diffraction MTF data for an optical system at low temperatures.

[0059] Figure 21 It shows Figure 13 The graph shows the aberration characteristics of the optical system at low temperatures.

[0060] Figure 22 It shows Figure 13 The diffraction MTF graph of the optical system shown at high temperature.

[0061] Figure 23 It shows Figure 13 The graph shows the aberration characteristics of the optical system at high temperature.

[0062] Figure 24 It shows Figure 13 A graph showing the peripheral light intensity ratio of the optical system shown.

[0063] Figure 25 2 is a cross-sectional view of an optical system and an image pickup device module including the optical system according to a third embodiment.

[0064] Figure 26 It shows Figure 25 A table of aspheric coefficients of lenses in an optical system.

[0065] Figure 27 It shows Figure 25 A table showing the thickness of each lens in an optical system and the gaps between adjacent lenses.

[0066] Figure 28 It shows Figure 25 A table showing sag values ​​of the lens surfaces of the first to seventh lenses in the optical system.

[0067] Figure 29 It shows Figure 25 Table of the inclination angles of the lens surfaces of the first to seventh lenses in the optical system.

[0068] Figure 30 It shows Figure 25 A graph showing the diffraction MTF data of an optical system at room temperature.

[0069] Figure 31 It shows Figure 25 A graph showing aberration characteristics of an optical system at room temperature.

[0070] Figure 32 It shows Figure 25 The shown optical system is a graph of data on diffraction MTF (Modulation Transfer Function) at low temperatures.

[0071] Figure 33 It shows Figure 25 This is a graph showing data on aberration characteristics of the optical system at low temperatures.

[0072] Figure 34 It shows Figure 25 A graph of the diffraction MTF data of the optical system at high temperature.

[0073] Figure 35 It shows Figure 25 A graph showing the aberration characteristics of the optical system at high temperatures.

[0074] Figure 36 It shows Figure 25 A graph of the peripheral light intensity ratio of the optical system.

[0075] Figure 37 is a side sectional view of an optical system and an image pickup device module including the optical system according to a fourth embodiment.

[0076] Figure 38 It shows Figure 37 A table of aspheric coefficients of lenses in an optical system.

[0077] Figure 39 It shows Figure 37 A table showing the thickness of each lens in an optical system and the gaps between adjacent lenses.

[0078] Figure 40 It shows Figure 37 A table showing sag values ​​of the lens surfaces of the first to seventh lenses in the optical system.

[0079] Figure 41 It shows Figure 37Table of the inclination angles of the lens surfaces of the first to seventh lenses in the optical system.

[0080] Figure 42 It shows Figure 37 The shown optical system is a graph of data on diffraction MTF (Modulation Transfer Function) at room temperature.

[0081] Figure 43 It shows Figure 37 This is a graph showing data on aberration characteristics of the optical system at room temperature.

[0082] Figure 44 It shows Figure 37 A graph showing diffraction MTF data for an optical system at low temperatures.

[0083] Figure 45 It shows Figure 37 This is a graph showing data on aberration characteristics of the optical system at low temperatures.

[0084] Figure 46 It shows Figure 37 A graph showing the diffraction MTF data for an optical system at high temperature.

[0085] Figure 47 It shows Figure 37 This is a graph showing data on aberration characteristics of the optical system at high temperatures.

[0086] Figure 48 It shows Figure 37 A graph showing the peripheral light intensity ratio of the optical system shown.

[0087] Figure 49 is an example of a vehicle equipped with an optical system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0088] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0089] However, the present invention is not limited to the given exemplary embodiments described, but may be implemented in various forms, and one or more components of the exemplary embodiments may be optionally combined or replaced between the embodiments within the scope of the present invention.

[0090] In addition, the terms (including technical terms and scientific terms) used in the embodiments of the present invention should be interpreted according to the meaning that a person of ordinary skill in the art to which the present invention belongs, unless explicitly defined and described specifically, and commonly used terms (for example, terms defined in dictionaries) should be interpreted according to their contextual meanings in the relevant art.

[0091] Furthermore, the terms used in the embodiments of the present invention are intended to describe the embodiments but are not intended to limit the present invention.

[0092] In this specification, unless the context requires otherwise, the singular may also include the plural, and a reference to "at least one (or more) of A and (or) B and C" may include one or more of any combination of A, B and C that can be combined.

[0093] In addition, the terms first, second, A, B, (a), (b), etc. may be used to describe components of embodiments of the present invention. Such terms are intended only to distinguish one component from another, and are not intended to limit the nature or order or sequence of such components by such terms.

[0094] In addition, when a component is described as being “connected,” “coupled” or “attached” to another component, it may include the case where the component is directly “connected,” “coupled” or “attached” to another component, as well as the case where the component is “connected,” “coupled” or “attached” to another component between the component and the other component.

[0095] In addition, when it is described that each component is formed or disposed “above” or “below”, “above” or “below” includes not only a case where the two components are in direct contact with each other, but also a case where one or more other components are formed or disposed between the two components. In addition, when expressed as “above” or “below”, it can include the meaning of upward as well as downward relative to a single component.

[0096] In the description of the present invention, the "object-side surface" may refer to the surface of a lens facing the object side relative to the optical axis (OA), and the "sensor-side surface" may refer to the surface of a lens facing the imaging surface (image sensor) relative to the optical axis. The "object-side surface" may be referred to as the "object surface," and the "sensor-side surface" may be referred to as the "image-side surface." The convex surface of a lens may refer to a convex shape in the optical axis or paraxial region, and the concave surface of a lens may refer to a concave shape in the optical axis or paraxial region. The radius of curvature, center thickness, and optical axis gap (spacing) between lenses listed in the lens data sheet may refer to values ​​measured along the optical axis (unit: mm). The vertical direction may refer to a direction perpendicular to the optical axis, and the end of a lens or lens surface may refer to the end of the effective area (zone) of the lens through which incident light passes. Depending on the measurement method, the size of the effective diameter of a lens surface may have a measurement error of up to ±0.4 mm. The term "paraxial region (paraxial) zone" refers to a very narrow area near the optical axis where the distance from the optical axis (OA) to the light is almost zero. Hereinafter, the term "optical axis" may refer to the center of each lens or a very narrow area near the optical axis.

[0097] like Figure 1 、 Figure 13 、 Figure 25 and Figure 37 As shown, the optical systems (1000, 1100, 1200, 1300) according to the first to fourth embodiments of the present invention may include five or more lenses. The optical systems (1000, 1100, 1200, 1300) and the camera module including the optical systems may be installed inside or outside a vehicle to monitor the driver or sense external objects or lanes. The lens material may be selected from glass or plastic, and the thermal expansion coefficient of glass is smaller than that of plastic. In order to suppress changes in the focal length imaging position due to temperature changes, glass lenses are used. However, glass lenses are more expensive than plastic lenses and face challenges in meeting cost reduction requirements. Therefore, the lenses within the optical systems (1000, 1100, 1200, 1300) need to be a hybrid configuration combining glass lenses and plastic lenses. By using plastic lenses, the optical systems (1000, 1100, 1200, 1300) can achieve a lightweight and low-cost design by reducing the thickness of the plastic lenses, and the plastic lenses can provide good correction of various aberrations such as spherical aberration and chromatic aberration. Additionally, the plastic lens can provide an aspherical lens, thereby minimizing distortion in the peripheral region.

[0098] The optical system (1000, 1100, 1200, 1300) may include n lenses, wherein the nth lens is the last lens adjacent to the image sensor (500), and the n-1th lens may be the lens closest to the last lens. n is an integer greater than or equal to 6, such as 6 or 8. The ratio of glass lenses to plastic lenses among the n lenses may be in the range of 2:5 to 3:4.

[0099] At least one lens closest to the subject in the optical system (1000, 1100, 1200, 1300) can be made of glass. At least one of the two or fewer lenses closest to the subject, for example, one lens, can be made of a glass material. Because the thermal expansion coefficient of a glass lens is smaller than that of a plastic lens, the glass lens can be disposed in an area adjacent to the exterior of the lens barrel.

[0100] At least one lens adjacent to an aperture (diaphragm) in the optical system (1000, 1100, 1200, 1300) may be made of glass. A lens adjacent to the aperture (diaphragm) on the sensor side may also be made of glass. The lens disposed adjacent to the aperture (diaphragm) has a significant influence within the optical system (1000, 1100, 1200, 1300), and therefore, a lens made of a glass material may be disposed to minimize changes in contraction and expansion due to temperature changes.

[0101] In the optical system (1000, 1100, 1200, 1300), at least one lens closest to the image sensor (500) may be made of a plastic material. For example, at least two lenses closest to the image sensor (500) may be made of a plastic material, and preferably, at least two lenses adjacent to the image sensor (500) may be made of a plastic material. That is, since the nth and n-1th lenses in the optical system (1000, 1100, 1200, 1300) are arranged as plastic lenses, various aberrations of incident light on the image sensor (500) can be corrected.

[0102] In the optical systems (1000, 1100, 1200, 1300), lenses made of plastic material may be arranged continuously, and lenses made of glass material may be arranged continuously. In the optical systems (1000, 1100, 1200, 1300), lenses made of plastic material may be arranged between lenses made of glass material. In the optical systems (1000, 1100, 1200, 1300), glass lenses may be arranged between plastic lenses.

[0103] Each lens (101 to 107, 201 to 207, 301 to 307, 401 to 407) may have an object-side surface and a sensor-side surface. The number of lenses having aspherical sensor-side surfaces and aspherical object-side surfaces in the optical system may be greater than the number of plastic lenses. The number of lenses having spherical sensor-side surfaces and spherical object-side surfaces in the optical system may be less than the number of lenses having aspherical surfaces on both sides. The optical system (1000, 1100, 1200, 1300) includes more aspherical lenses than spherical lenses, thereby being able to correct various aberrations.

[0104] Among the lenses in the optical system (1000, 1100, 1200, 1300), the lens with the highest refractive index can be positioned closer to the object. The maximum refractive index can be 1.6 or higher. The lens with the highest refractive index can increase the dispersion of incident light and allow the center thickness to be thinner than the edge thickness. In addition, since the lens with the highest refractive index is positioned closer to the object, it facilitates changes in the radius of curvature of subsequent lenses and allows the center thickness to be increased.

[0105] like Figure 1 、 Figure 13 、 Figure 25 and Figure 37As shown, the optical systems (1000, 1100, 1200, 1300) according to the first to fourth embodiments of the present invention may include a plurality of lens groups (LG1, LG2). In detail, each of the plurality of lens groups (LG1, LG2) includes at least one lens. For example, the optical systems (1000, 1100, 1200, 1300) may include a first lens group (LG1) and a second lens group (LG2) sequentially arranged along the optical axis (OA) from the object side toward the image sensor (500). The optical systems (1000, 1100, 1200, 1300) may include n lenses, wherein the nth lens is the last lens, and the n-1th lens may be the lens closest to the last lens. n is an integer of 5 or greater, for example, 5 to 9.

[0106] The optical system (1000, 1100, 1200, 1300) may include a first lens group (LG1) and a second lens group (LG2), wherein the first lens group (LG1) includes a plurality of lenses disposed on the object side relative to an aperture (diaphragm), and the second lens group (LG2) includes a plurality of lenses disposed on the sensor side relative to the aperture (diaphragm). The number of lenses in each of the first lens group (LG1) and the second lens group (LG2) may be different. The number of lenses in the second lens group (LG2) may be greater than the number of lenses in the first lens group (LG1).

[0107] The first lens group (LG1) may include at least one lens. The first lens group (LG1) may include three or fewer lenses. The first lens group (LG1) may preferably include two lenses. The second lens group (LG2) may include four or more lenses. The second lens group (LG2) may include five lenses.

[0108] The composite focal length of the first lens group (LG1) is defined as F_LG1, and the composite focal length of the second lens group (LG2) is defined as F_LG2. The signs of F_LG1 and F_LG2 may differ. F_LG1 may have a negative (-) value, and F_LG2 may have a positive (+) value. This allows light to diverge in one of the two lens groups and then converge in the other lens group. The difference between the absolute value of the composite focal length (F_LG1) of the first lens group (LG1) and the absolute value of the composite focal length (F_LG2) of the second lens group (LG2) may satisfy a range of 1 to 3.

[0109] An aperture (stop) may be provided between the second lens (102, 202, 302, 402) and the third lens (103, 203, 303, 403), the first lens group (LG1) may include the first to second lenses (101 to 102, 201 to 202, 301 to 302, 401 to 402), and the second lens group (LG2) may include the third to seventh lenses (103 to 107, 203 to 207, 303 to 307, 403 to 407). The composite focal length of the first lens group (LG1) has a negative (-) sign, and at least one of the focal lengths of the first lens (101, 201, 301, 401) and the second lens (102, 202, 302, 402) may have the same sign as the focal length of the first lens group (LG1). The Abbe number of the lens in the first lens group (LG1) having the same sign as the composite focal length of the first lens group (LG1) may be 40 or higher. The Abbe number of the first lens (101, 201, 301, 401) and the second lens (102, 202, 302, 402) may be 40 or higher, preferably within a range of 50 to 70. This makes it possible to eliminate aberrations in light passing through each lens. However, a lens with relatively low refractive power may exceptionally have an Abbe number of 40 or less.

[0110] The second lens group (LG2) has a positive (+) sign for the combined focal length, and at least one of the focal lengths of the third lens (103, 203, 303, 403), the fourth lens (104, 204, 304, 404), and the sixth lens (106, 206, 306, 406) may have the same sign as the focal length of the second lens group (LG2). In the second lens group (LG2), the Abbe number of the lens having the same sign as the composite focal length of the second lens group (LG2) may be 40 or greater. At least one of the fifth lens (105, 205, 305, 405), the sixth lens (106, 206, 306, 406), and the eighth lens (108, 208, 308, 408) may have an Abbe number of 40 or greater. This makes it possible to eliminate aberrations in light passing through each lens. However, as an exception, a lens with relatively small refractive power may have an Abbe number of 40 or less.

[0111] In the optical system (1000, 1100, 1200, 1300), a lens having a maximum effective diameter can be disposed at the center of the object side and the sensor side. As the distance from the object side to the sensor side increases, the effective diameter of the lens can first increase and then decrease. As the distance from the object side to the sensor side increases, the effective diameter of the lens can first decrease, then increase, and then decrease again. Therefore, light entering the optical system (1000, 1100, 1200, 1300) diverges from the optical axis and then converges back toward the optical axis, enabling the optical system (1000, 1100, 1200, 1300) to form a stable optical path.

[0112] The effective diameter is the diameter of the effective area of ​​each lens where light enters. The effective diameter is the length in the direction perpendicular to the optical axis (X, Y), and is the average of the effective diameters on the object side and the sensor side of each lens. "Lens surface diameter" may refer to "effective diameter of the lens." "Lens diameter" may refer to the total diameter of the lens, including the flange portion outside the effective area of ​​the lens. Although Figure 1 、 Figure 13 、 Figure 25 and Figure 37 The lens flange is not shown in the figure, but it can be a portion protruding from the side of the lens perpendicular to the optical axis and used to attach the lens to the lens barrel. The flange may not allow effective light to enter. To connect the lenses to the lens barrel, spacers can be additionally provided between the flanges of different lenses.

[0113] Each lens (101 to 107, 201 to 207, 301 to 307, 401 to 407) may include an effective area and an ineffective area. The effective area may be the area through which light incident on each lens passes. In other words, the effective area may be defined as an effective area or effective path where incident light is refracted to achieve optical properties. An ineffective area may be provided around the effective area. The ineffective area may be an area where effective light does not enter from a plurality of lenses. In other words, the ineffective area may be an area that is unrelated to optical properties. In addition, the end of the ineffective area may be an area fixed to a lens barrel or a similar structure that accommodates the lens.

[0114] In the optical system (1000, 1100, 1200, 1300), the TTL (total top length) can be greater than five times Imgh, for example, six times or more and eight times or less. The TTL (total track length) is the distance from the center of the object-side surface of the first lens to the image surface of the image sensor (500) along the optical axis (OA). Imgh is half the maximum diagonal length of the image sensor (500). In the optical system (1000, 1100, 1200, 1300), the effective focal length (EFL) is 9 mm or greater, and the horizontal field of view (FOV_H) is 145 degrees or greater and less than 160 degrees, so that the optical system can be provided as an optical system for vehicle interior monitoring in a vehicle camera module. For example, the optical system and the camera module according to the embodiment can be applied to a camera device of an ADAS (advanced driver assistance system) installed inside or outside a vehicle.

[0115] The optical system (1000, 1100, 1200, 1300) may have a TTL / Imgh ratio of 5 or higher and 7 or lower, for example, 5.5 or higher and 6.5 or lower. By setting the TTL / Imgh ratio of the optical system (1000, 1100, 1200, 1300) to 5 or higher and 7 or lower, an optical system for a vehicle lens can be provided. Therefore, the optical system (1000, 1100, 1200, 1300) can provide an image without exaggeration or distortion.

[0116] In the optical system (1000, 1100, 1200, 1300), the effective diameter of at least one plastic lens may be smaller than the length of the image sensor (500). The effective diameter is the diameter or length of the effective area through which light enters. The length of the image sensor (500) is the maximum length of a diagonal line in a direction perpendicular to the optical axis (OA). In the optical system (1000, 1100, 1200, 1300), the number of lenses having an effective diameter greater than the length of the image sensor (500) is 65% or more, or 75% or more, and the number of lenses having an effective diameter less than the length of the image sensor (500) may be less than 30%, or less than 25%.

[0117] The lens unit can be composed of a combination of glass lenses and plastic lenses. The number of plastic lenses can account for more than 60% of the total number of lenses and can be in the range of 65% to 85%. Therefore, when more plastic lenses are incorporated into the camera module, the weight of the camera module can be reduced. In addition, plastic materials offer advantages such as easy polishing and processing, high resistance to external impact, cost competitiveness, and easy material procurement. In addition, plastic lenses can correct various aberrations, thereby preventing optical performance degradation.

[0118] Embodiments of the present invention relate to mixing additional plastic lenses within an optical system (1000, 1100, 1200, 1300), thereby reducing the weight of a camera module, providing a more cost-effective manufacturing process, suppressing degradation of optical characteristics due to temperature changes, enabling various types of plastic lenses to replace glass lenses, and facilitating the polishing and processing of lens surfaces such as aspheric or free-form surfaces.

[0119] The effective diameter of the lens closest to the object side within the lens unit can be larger than the effective diameter of the lens closest to the image sensor (500). This allows the brightness of the optical system to be controlled. The effective diameter can be the average effective diameter of the object-side surface and the sensor-side surface of each lens. By controlling the effective diameter of each lens, the optical system (1000, 1100, 1200, 1300) can control incident light to compensate for resolution reduction and optical property degradation due to temperature changes, improve chromatic aberration control characteristics, and improve vignetting characteristics of the optical system (1000, 1100, 1200, 1300).

[0120] The lens unit may be composed of a first lens (101, 201, 301, 401), a second lens (102, 202, 302, 402), a third lens (103, 203, 303, 403), a fourth lens (104, 204, 304, 404), a fifth lens (105, 205, 305, 405), a sixth lens (106, 206, 306, 406) and a seventh lens (107, 207, 307, 407).

[0121] The lens unit can be provided in a camera module having an inner barrel on one side or the entire inner surface of a lens barrel. The lens unit can be provided in a camera module having multiple inner barrels surrounding the periphery of different lenses of the lens barrel. The lens unit can be provided in a camera module having a first inner barrel in contact with the outer surface of at least one lens of the lens barrel and a second inner barrel in contact with the outer surface of at least one lens of the lens barrel. The lens unit can be provided in a camera module having multiple inner barrels provided between the outer sides of at least one or two lenses and the lens barrel. The lens unit can be provided in a camera module having multiple inner barrels made of a material different from that of the lens barrel.

[0122] Among the lenses constituting the lens unit, at least some of the glass lenses can be arranged in a lens barrel, and at least some of the plastic lenses can be arranged in an inner barrel. This enables the optical system (1000, 1100, 1200, 1300) to maintain its resolution even when the temperature changes. The lens unit can be arranged in a camera module with a heterogeneous barrel, thereby minimizing the eccentricity of lenses such as plastic lenses that expand due to temperature changes. The lens barrel in which the lens unit is arranged can be equipped with multiple inner barrels within the lens barrel, thereby maintaining the resolution of the optical system due to temperature changes and suppressing the deformation of the lenses. Therefore, the effective diameter of at least some of the glass lenses included in the lens unit can be smaller than the effective diameter of at least some of the plastic lenses.

[0123] The number of lenses having an effective diameter greater than the average effective diameter of the plastic lenses in the lens unit may be one or more, for example, two or more. When the average effective diameter of the plastic lenses is PLca_Aver and the average effective diameter of the glass lenses is GLca_Aver, the condition PLca_Aver<GLca_Aver may be satisfied. In addition, the condition 1.8<GLca_Aver / PLca_Aver<2.1 may be satisfied. In addition, the relationship between the length of the image sensor (500) and the average effective diameter (PLca_Aver) of the plastic lenses may satisfy the condition 1.8<PLca_Aver / Imgh<2.1. In addition, the relationship between the average effective diameter of the glass lenses and the length of the image sensor (500) may satisfy the condition 1.5<GLca_Aver / Imgh<2. The difference between the maximum length of the image sensor (500) and the effective diameter of the plastic lenses may be kept small. Therefore, by placing the plastic lens having a small effective diameter adjacent to the image sensor (500), the plastic lens may disperse the color from the center of the image sensor (500) to the periphery.

[0124] The average effective diameter of the glass material can be 8 mm or larger, for example, in the range of 9 mm to 11 mm. The average effective diameter of the plastic material can be 8 mm or larger, for example, in the range of 9 mm to 11 mm. The lens with the smallest effective diameter can be made of plastic, and the lens with the largest effective diameter can be made of glass. Within the lens unit, the smallest effective diameter can be in the range of 7 mm to 9 mm, and the largest effective diameter can be in the range of 10 mm to 13 mm. The plastic lens can be designed to have a smaller effective diameter than the glass lens to prevent contact with the lens barrel, thereby minimizing changes in optical performance due to temperature changes. In addition, the optical system (1000, 1100, 1200, 1300) can control incident light to improve resolution and chromatic aberration control characteristics, and improve the vignetting characteristics of the optical system (1000, 1100, 1200, 1300).

[0125] The optical system (1000, 1100, 1200, 1300) or the camera module may include an image sensor (500). The image sensor (500) may detect light and convert it into an electrical signal. The image sensor (500) may detect light that continuously passes through a lens unit. The image sensor (500) may include a device that can detect incident light, such as a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor).

[0126] The optical system (1000, 1100, 1200, 1300) or the camera module may include a filter (600). The filter (600) may be provided between the last lens and the image sensor (500). The filter (600) may be provided between the lens closest to the sensor side among the lenses of the lens unit and the image sensor (500). For example, the filter (600) may be provided between the nth lens and the image sensor (500).

[0127] A cover glass may be provided between the filter (600) and the image sensor (500) to protect the upper portion of the image sensor (500) and prevent a reduction in the reliability of the image sensor (500). The cover glass may be removed. The cover glass may be a protective glass.

[0128] The optical filter (600) may include an infrared filter or an infrared cutoff filter (IR cutoff). The optical filter (600) may transmit light within a set wavelength band and filter out light from other wavelength bands. When the optical filter (600) includes an infrared filter, it may prevent radiant heat emitted from external light from being transmitted to the image sensor (500). Alternatively, the optical filter (600) may transmit visible light and reflect infrared light.

[0129] The optical system (1000, 1100, 1200, 1300) according to the embodiment may include an aperture (diaphragm). The aperture can control the amount of light entering the optical system (1000, 1100, 1200, 1300). In a lens disposed between an object and the aperture, the effective diameter of the lens surface tends to increase as one moves from the object side toward the aperture. In a lens disposed between the aperture and the sensor, the effective diameter of the lens surface tends to decrease as one moves from the aperture toward the sensor side. The tendency for the effective diameter of the lens surface to increase or decrease does not mean that the effective diameter of the lens surface only increases or decreases. For example, it also includes a case where the effective diameter of the lens surface increases and then decreases as the distance from the aperture to the sensor increases.

[0130] In the optical systems (1000, 1100, 1200, 1300) of the first to fourth embodiments, the sum of the refractive indices of the lenses in a lens unit can be 9 or greater, for example, in the range of 10 to 13, and the average refractive index can be in the range of 1.5 to 1.7. The sum of the Abbe numbers of each lens can be 340 or greater, for example, in the range of 350 to 380, and the average Abbe number can be 60 or less, for example, in the range of 45 to 55. The total center thickness of all lenses can be 18 mm or greater, for example, in the range of 19 mm to 21 mm, and the average center thickness can be in the range of 2 mm to 3 mm. The total center gap between the lenses along the optical axis (OA) can be 4 mm or greater, for example, in the range of 5 mm to 7 mm, and can be less than the total center thickness of the lenses. In addition, the average effective diameter of each lens surface (S1 to S14) in the lens unit can be 3 mm or greater, for example, in the range of 3.5 mm to 4.5 mm.

[0131] In the optical systems according to the first to fourth embodiments of the present invention, the aperture number (F-number) may be 1.8 or less, for example, in the range of 1.5 to 1.7. The vehicle optical system may have a horizontal field of view (FOV_H) in the Y-axis direction that is greater than 40 degrees and less than 60 degrees, for example, in the range of 45 to 50 degrees. In addition, the vertical field of view may be provided at an angle smaller than the horizontal field of view. The vertical field of view (FOV_V) may be greater than 20 degrees and less than 35 degrees, for example, in the range of 25 to 30 degrees. The sensor length in the horizontal direction (Y) may be 8.64 mm ± 0.5 mm, and the sensor height in the vertical direction (X) may be 5.58 mm ± 0.5 mm. The horizontal field of view (FOV_H) is a field of view based on the horizontal (Horizontal) length of the image sensor, and the vertical field of view (FOV_V) is a field of view based on the vertical (Vertical) length of the image sensor. Therefore, changes in the focal imaging position due to temperature changes can be suppressed, and the imaging apparatus can be provided as a vehicle-mounted imaging apparatus in which various aberrations are effectively corrected.

[0132] Optical systems used in vehicle camera systems are typically designed based on the horizontal field of view (FOV) rather than the entire field of view, as they are intended to monitor road conditions. The optical system according to embodiments is designed with a certain margin around the inscribed circle of the image sensor. This ensures optical performance within the specified horizontal FOV (FOV_H).

[0133] Since the embodiment is an optical system applied to an in-vehicle camera device, the first lens (101, 201, 301, 401) can be provided as a glass material even if both a plastic lens and a glass lens are used. This is because glass materials have the advantages of being scratch-resistant and insensitive to external temperature compared to plastic materials. The first lens (101, 201, 301, 401) can be a glass molded lens made of a glass material having an aspherical shape. The glass molded lens can be manufactured by placing an optical glass ingot inside a mold having an aspherical shape and subjecting it to a heating and compression process.

[0134] In order to effectively prevent scratches caused by foreign objects when installed in a vehicle interior, a glass lens can be used as the first lens (101, 201, 301, 401), and the object-side surface of the first lens (101, 201, 301, 401) can have a gently curved surface to avoid contact with external structures. This minimizes the occurrence of scratches caused by contact with external structures. For driver monitoring, front / rear vehicle imaging, or lane detection, and detection of sudden objects around the vehicle during vehicle operation, the field of view can be greater than 40 degrees and less than 60 degrees, for example, in the range of 45 degrees to 50 degrees. This horizontal field of view can be a preset angle for an advanced driver assistance system (ADAS).

[0135] The optical system (1000, 1100, 1200, 1300) according to the embodiment may further include a reflective member for changing the light path. The reflective member may be implemented as a prism that reflects incident light toward the lens in the optical system (1000, 1100, 1200, 1300). Hereinafter, the optical system according to the embodiment will be described in detail.

[0136] An optical system according to a first embodiment of the present invention will be described.

[0137] Figure 1 is a side sectional view of an optical system and an image pickup device module including the optical system according to the first embodiment, Figure 2 It shows Figure 1 Table of aspheric coefficients of lenses in optical systems, Figure 3 It shows Figure 1 A table showing the thickness of each lens in the optical system and the gaps between adjacent lenses. Figure 4 It shows Figure 1 A table showing sag values ​​of lens surfaces of the first lens to the seventh lens in the optical system of FIG. Figure 5 It shows Figure 1 Table of inclination angle values ​​of the lens surfaces of the first lens to the seventh lens in the optical system, Figure 6 It shows Figure 1 This is a graph showing the diffraction MTF (Modulation Transfer Function) data of an optical system at room temperature. Figure 7 It shows Figure 1 A graph showing the aberration characteristics of an optical system at room temperature. Figure 8 It shows Figure 1 The graph of diffraction MTF data of the optical system at low temperature is shown. Figure 9 It shows Figure 1 The graph of aberration characteristic data of the optical system at low temperature is shown in FIG. Figure 10 It shows Figure 1 The graph of diffraction MTF data of the optical system at high temperature is shown. Figure 11 It shows Figure 1 The graph of aberration characteristic data of the optical system at high temperature is shown, and Figure 12 It shows Figure 1 A graph showing the peripheral light intensity ratio of the optical system shown.

[0138] Reference Figure 1The optical system (1000) may include a lens unit, and the lens unit may include a first lens (101) to a seventh lens (107). The first lens to the seventh lens (101 to 107) may be continuously arranged along an optical axis (OA) of the optical system (1000). Light corresponding to information of an object may pass through the first lens (101) to the seventh lens (107) and the filter (600) and enter the image sensor (500).

[0139] The first lens (101) may be arranged closest to the object side. The first lens (101) may be arranged farthest from the sensor side. The first lens (101) may have a negative (-) refractive power relative to the optical axis (OA). The first lens (101) may include a plastic material or a glass material and may be made of glass, for example. The first lens (101) made of glass can reduce changes in the center position and the curvature radius due to temperature changes caused by the surrounding environment and can protect the incident side of the optical system (1000).

[0140] Based on the optical axis, the object side first surface (S1) of the first lens (101) is convex, and the sensor side second surface (S2) may be concave. The first lens (101) may have a convex meniscus shape on the object side. The first lens (101) may have a concave meniscus shape on the sensor side. The first lens (101) may be made of a glass material and may have an aspherical surface. At least one or both of the first surface (S1) and the second surface (S2) may be aspherical. The aspheric coefficients of the first surface and the second surface (S1, S2) may be as follows Figure 2 At least one or both of the first surface (S1) and the second surface (S2) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0141] Due to the refractive properties of the first lens (101), the second lens (102) can be spaced further apart from the first lens (101). In other words, the center gap between the first lens (101) and the second lens (102) can be the largest in the lens unit.

[0142] The refractive index (n1) of the first lens (101) may satisfy the condition n1>1.6 or n1>1.62. When the refractive index (n1) of the first lens (101) satisfies the above condition, the curvature radius of the first lens and the second lens (101, 102) can be increased, thereby making lens manufacturing easier. If the refractive index (n1) of the first lens (101) is less than the condition, the refractive power of the first lens and the second lens (101, 102) must be increased by forming a sharply concave or convex lens surface, which makes lens manufacturing difficult, increases the defect rate, and may lead to a decrease in the yield rate.

[0143] The second lens (102) may be arranged second from the object side. The second lens (102) may be arranged sixth from the sensor side. The second lens (102) may be arranged between the first lens (101) and the third lens (103). The second lens (102) may have a negative (-) refractive power on the optical axis (OA). The second lens (102) may include a plastic or glass material. For example, the second lens (102) may be provided as a plastic material.

[0144] Based on the optical axis (OA), the object side third surface (S3) of the second lens (102) may be concave, and the sensor side fourth surface (S4) may be convex. The second lens (102) may have a convex meniscus shape toward the sensor side. The second lens (102) may have a concave meniscus shape on the object side. The second lens (102) may be made of a plastic material and may be aspherical. At least one or both of the third surface (S3) and the fourth surface (S4) may be aspherical. The aspheric coefficients of the third surface and the fourth surface (S3, S4) may be as follows Figure 2 At least one or both of the third surface (S3) and the fourth surface (S4) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0145] An aperture (stop) can be provided around the periphery of the sensor-side fourth surface (S4) of the second lens (102). An aperture (stop) can be provided around the periphery of the sensor-side fifth surface (S5) of the third lens (103). The aperture can reduce the TTL within the field of view and achieve miniaturization of the optical system. Therefore, it is possible to prevent a decrease in the weight-based yield (yield by weight) of the optical system and improve production efficiency. In addition, by reducing the TTL within the horizontal field of view (FOV_H) of 40 degrees to 50 degrees, the optical system can be miniaturized.

[0146] The third lens (103) may be arranged third from the object side. The third lens (103) may be arranged fifth from the sensor side. The third lens (103) may be arranged between the second lens (102) and the fourth lens (104). The third lens (103) may have positive (+) refractive power on the optical axis (OA). The third lens (103) may include a plastic or glass material. For example, the third lens (103) may be provided as a glass material.

[0147] The object-side fifth surface (S5) of the third lens (103) may be convex, and the sensor-side sixth surface (S6) may be convex based on the optical axis. The third lens (103) may have a shape in which both surfaces are convex. The third lens (103) may be made of a glass material and may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be arranged so as not to have a critical point from the optical axis (OA) to the end of the effective area.

[0148] The fourth lens (104) may be provided as the fourth lens on the object side. The fourth lens (104) may be provided as the fourth lens on the sensor side. The fourth lens (104) may be provided between the third lens (103) and the fifth lens (105). The fourth lens (104) may have positive (+) or negative (-) refractive power relative to the optical axis (OA). The fourth lens (104) may have positive (+) refractive power. The fourth lens (104) may include a plastic or glass material. For example, the fourth lens (104) may be provided as a plastic material.

[0149] Based on the optical axis, the object-side seventh surface (S7) of the fourth lens (104) may be convex, and the sensor-side eighth surface (S8) may be convex. The fourth lens (104) may have a shape in which both surfaces are convex. The fourth lens (104) may be made of a plastic material and may be aspherical. At least one or both of the seventh surface (S7) and the eighth surface (S8) may be aspherical. The aspherical coefficients of the seventh surface and the eighth surface (S7, S8) may be as follows: Figure 2 At least one or both of the seventh surface (S7) and the eighth surface (S8) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0150] The fifth lens (105) may be arranged to be fifth from the object side. The fifth lens (105) may be arranged to be third from the sensor side. The fifth lens (105) may be arranged between the fourth lens (104) and the sixth lens (106). The fifth lens (105) may have positive (+) or negative (-) refractive power relative to the optical axis (OA). The fifth lens (105) may have negative (-) refractive power. The fifth lens (105) may include a plastic or glass material. For example, the fifth lens (105) may be provided as a plastic material.

[0151] The fifth lens (105) may have a ninth surface (S9) that is convex on the object side and a tenth surface (S10) that is concave on the sensor side relative to the optical axis (OA). The fifth lens (105) may have a convex meniscus shape on the object side. The fifth lens (105) may have a concave meniscus shape on the sensor side. The fifth lens (105) may be made of a plastic material and may be aspherical. At least one or both of the ninth surface (S9) and the tenth surface (S10) may be aspherical. The aspheric coefficients of the ninth surface and the tenth surface (S9, S10) may be as follows Figure 2 At least one or both of the ninth surface (S9) and the tenth surface (S10) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0152] The sixth lens (106) may be provided as the sixth lens from the object side. The sixth lens (106) may be provided as the second lens from the sensor side. The sixth lens (106) may be provided between the fifth lens (105) and the seventh lens (107). The sixth lens (106) may have positive (+) or negative (-) refractive power along the optical axis (OA). The sixth lens (106) may have positive (+) refractive power. The sixth lens (106) may include a plastic or glass material. For example, the sixth lens (106) may be provided as a plastic material.

[0153] The sixth lens (106) may have an 11th surface (S11) that is convex on the object side and a 12th surface (S12) that is convex on the sensor side relative to the optical axis (OA). The sixth lens (106) may have a shape in which both surfaces are convex. The sixth lens (106) may be made of a plastic material and may be aspherical. At least one or both of the 11th surface (S11) and the 12th surface (S12) may be aspherical. The aspherical coefficients of the 11th surface and the 12th surface (S11, S12) may be as follows: Figure 2 Available in S1 and S2 of L6.

[0154] The 11th surface (S11) of the 6th lens (106) can be configured to have no critical point from the optical axis (OA) to the end of the effective area. The 12th surface (S12) of the 6th lens (106) can include a critical point from the optical axis (OA) to the end of the effective area. When the 12th surface (S12) has a critical point, the critical point can be located in the range of 75% to 80% of the effective radius (r62) from the optical axis (OA), preferably in the range of 76% to 77%. The critical point of the 12th surface (S12) can be located in the range of 3.3 mm to 4 mm from the optical axis (OA), preferably in the range of 3.5 mm to 3.6 mm.

[0155] The seventh lens (107) may be disposed farthest from the object side. The seventh lens (107) may be disposed closest to the image sensor (500). The seventh lens (107) may have positive (+) or negative (-) refractive power on the optical axis (OA). The seventh lens (107) may have negative (-) refractive power. The seventh lens (107) may include a plastic or glass material. For example, the seventh lens (107) may be provided as a plastic material.

[0156] The seventh lens (107) may have a 13th surface (S13) that is concave on the object side and a 14th surface (S14) that is concave on the sensor side relative to the optical axis (OA). The seventh lens (107) may have a concave shape on both surfaces. At least one or both of the 13th surface (S13) and the 14th surface (S14) may be aspherical. The aspheric coefficients of the 13th surface and the 14th surface (S13, S14) may be as follows: Figure 2 Available in S13 and S14 of L7.

[0157] The 13th surface (S13) of the 7th lens (107) may extend from the optical axis (OA) to the end of the effective area including a critical point. If the 13th surface (S13) has a critical point, the critical point may be located in the range of 65% to 75% of the effective radius (r71) from the optical axis (OA), preferably in the range of 69% to 72%. The critical point of the 13th surface (S13) may be located in the range of 3.5mm to 4mm from the optical axis (OA), preferably in the range of 3.6mm to 3.7mm. The 14th surface (S14) of the 7th lens (107) may extend from the optical axis (OA) to the end of the effective area including a critical point. If the 14th surface (S14) has a critical point, the critical point may be located in the range of 65% to 75% of the effective radius (r72) from the optical axis (OA), preferably in the range of 69% to 72%. The critical point of the 14th surface (S14) may be located within a range of 3.5 mm to 4 mm, preferably within a range of 3.6 mm to 3.7 mm, from the optical axis (OA).

[0158] The seventh lens (107) may be a plastic lens that is closest to the image sensor (500). In addition, by arranging two or more plastic lenses adjacent to the image sensor (500), aberrations such as spherical aberration and chromatic aberration can be improved by having a lens surface with an aspherical shape, and resolution can be controlled. Furthermore, by arranging the plastic lens adjacent to the image sensor (500), it is possible to be less sensitive to assembly tolerances than glass lenses. In other words, being less sensitive to assembly tolerances means that even if the assembly differs slightly from the design during assembly, the optical performance may not be significantly affected. Furthermore, by providing the two lenses (106, 107) adjacent to the image sensor (500) with a plastic material, the optical performance can be improved by, for example, improving aberration characteristics and preventing resolution degradation through the aspherical lens surface.

[0159] [Table 1]

[0160]

[0161]

[0162] Table 1 shows the surface number (Surface), curvature radius (Radius), center thickness of each lens or distance between lens surfaces (Thickness), refractive index (Index, nd), Abbe number (Abbe, vd), effective radius (Semi Aperture), and focal length (Focal length) of the lenses according to the first embodiment of the present invention. Here, the unit of the curvature radius and thickness or distance may be mm.

[0163] [Table 2]

[0164]

[0165]

[0166] Table 2 shows the items corresponding to the above mathematical formula in the optical system (1000) of the embodiment, and the optical system (1000) includes TTL (total track length) (mm), BFL (back focal length), effective focal length (F) (mm), ImgH (mm), effective diameter (CA) (mm), thickness (mm), TTL (mm), optical axis distance TD from the first surface (S1) to the fourteenth surface (S14) (mm), sum of refractive indices, sum of Abbe numbers, sum of thicknesses (mm), sum of distances between adjacent lenses, effective diameter characteristics, sum of refractive indices of glass lenses, sum of refractive indices of plastic materials, field of view (FOV_H) (degrees), edge thickness (ET), aperture number, and other related parameters.

[0167] The center thicknesses of the first to seventh lenses (101 to 107) are indicated as CT1 to CT7, the edge thicknesses at the ends of the effective areas of each lens are indicated as ET1 to ET7, the center gaps between adjacent lenses are indicated as CG1 to CG6, and the edge gaps between the edges of each lens are indicated as EG1 to EG6. The back focus (BFL) is the optical axis distance from the image sensor (500) to the center of the last lens. The TTL is the optical axis distance from the center of the first surface (S1) of the first lens (101) to the image surface of the image sensor (500).

[0168] like Figure 2 As shown, the lens surfaces of the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens (101, 102, 104, 105, 106, 107) in the lens unit of the first embodiment may include aspheric surfaces having a 30th-order aspheric coefficient. For example, the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens (101, 102, 104, 105, 106, 107) may include lens surfaces having a 30th-order aspheric coefficient. As described above, the aspheric surface having a 30th-order aspheric coefficient (a non-zero value) can significantly change the aspheric shape in the peripheral region, thereby effectively correcting the optical performance in the peripheral region of the field of view (FOV).

[0169] The thicknesses (T1 to T7) of the first to seventh lenses (101 to 107) and the gaps (G1 to G6) between adjacent lenses may be set. Figure 3 As shown, the thickness of each lens in the Y-axis direction (T1 to T7) can be expressed at intervals of 0.1 mm or 0.2 mm or greater, and the gap between each lens (G1 to G6) can be expressed at intervals of 0.1 mm or 0.2 mm or greater.

[0170] When comparing the absolute values ​​of the curvature radii of each lens, the curvature radius of the 13th surface (S13) of the 7th lens (107) on the optical axis (OA) is the largest among the lenses, and the curvature radius of the 12th surface (S12) of the 6th lens (106) may be the smallest among the lenses. The difference between the maximum curvature radius and the minimum curvature radius may be greater than 50 times, for example, in the range of 50 times to 60 times.

[0171] Among the object-side surfaces and sensor-side surfaces of the first to seventh lenses (101 to 107), the number of lens surfaces having a radius of curvature greater than 40° may be one or more but not more than four. This allows the radius of curvature of the lenses constituting the optical system (1000) to be designed to be mostly small, thereby satisfying the field of view, focal length, and total length of the lenses when they are installed in a vehicle.

[0172] 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 stronger refractive power to refract light through the plastic lens. In addition, in order to increase the refractive power, the curvature radius of the lens surface can be smaller.

[0173] The absolute value of the radius of curvature of the first surface (S1) of the first lens (101) may be greater than the absolute value of the radius of curvature of the second surface (S2). The absolute value of the radius of curvature of the third surface (S3) of the second lens (102) may be smaller than the absolute value of the radius of curvature of the fourth surface (S4). The absolute value of the radius of curvature of the fifth surface (S5) of the third lens (103) may be greater than the absolute value of the radius of curvature of the sixth surface (S6). The absolute value of the radius of curvature of the seventh surface (S7) of the fourth lens (104) may be smaller than the absolute value of the radius of curvature of the eighth surface (S8). The absolute value of the radius of curvature of the ninth surface (S9) of the fifth lens (105) may be greater than the absolute value of the radius of curvature of the tenth surface (S10). The absolute value of the radius of curvature of the eleventh surface (S11) of the sixth lens (106) may be greater than the absolute value of the radius of curvature of the twelfth surface (S12). An absolute value of a curvature radius of the thirteenth surface (S13) of the seventh lens (107) may be greater than an absolute value of a curvature radius of the fourteenth surface (S14).

[0174] The ratio of the curvature radius of each lens may satisfy the following conditions.

[0175] Condition 1: 1.5<|L1R1 / L1R|<2

[0176] Condition 2: 0.5<|L2R1 / L2R2|<1

[0177] Condition 3: 1.5<|L3R1 / L3R2|<2

[0178] Condition 4: 0.1<|L4R1 / L4R2|<0.5

[0179] Condition 5: 40<|L5R1 / L5R2|<50

[0180] Condition 6: 5<|L6R1 / L6R2|<10

[0181] Condition 7: 150 < |L7R1 / L7R2| < 200

[0182] When describing the center thickness (CT) of the lens based on the optical axis, the center thickness (CT4) of the fourth lens (104) may be the largest among the lenses, and the center thickness (CT1, CT5, CT7) of at least one of the first lens (101), the fifth lens (105), and the seventh lens (107) may be the smallest among the lenses. The difference between the maximum center thickness and the minimum center thickness of the lens may be within a range of 2 mm or more and 2.5 mm or less.

[0183] The center thickness of each lens may satisfy any one of the following conditions.

[0184] Condition 1: CT2, CT3, CT4, CT6 > CT1 = CT5 = CT7

[0185] Condition 2: CT3, CT4, CT6 > CT2 > CT1, CT3, CT5, CT7

[0186] Condition 3: CT4 > CT3 > CT1, CT2, CT5, CT6, CT7

[0187] Condition 4: CT4 > CT1, CT2, CT3, CT6, CT7

[0188] Condition 5: CT3, CT4 > CT6 > CT1, CT2, CT5, CT7

[0189] The center gaps (CG) between the lenses are described as follows: the center gap (CG1) between the first lens (101) and the second lens (102) may be the largest, and at least one of the center gap (CG3) between the third lens (103) and the fourth lens (104), the center gap (CG4) between the fourth lens (104) and the fifth lens (105), and the center gap (CG6) between the sixth lens (106) and the seventh lens (107) may be the smallest. The difference between the largest center gap and the smallest center gap among the spaced lens gaps may be 3 mm or more, for example, in the range of 3 mm to 4 mm.

[0190] The center gap between each lens can satisfy the following conditions.

[0191] Condition 1: CG1 > CG2, CG3, CG4, CG5, CG6

[0192] Condition 2: CG1, CG5 > CG2 > CG3, CG4, CG6

[0193] Condition 3: CG1, CG2, CG5 > CG3 = CG4 = CG6

[0194] Condition 4: CG1 > CG5 > CG2, CG3, CG4, CG6

[0195] Regarding the effective diameter, the lens with the largest effective diameter may be a lens made of a glass material. The lens with the largest effective diameter may be the fourth lens (104). Here, the effective diameter is the average of the effective diameter on the object side surface and the effective diameter on the sensor side surface of each lens. The lens surface with the largest effective diameter may be the seventh surface (S7) of the fourth lens (104). The lens with the smallest effective diameter may be the second lens (102). The lens surface with the smallest effective diameter may be the fourth surface (S4) of the second lens (102). The effective diameter of the plastic lens may be smaller than the effective diameter of the glass lens. The plastic lens may be disposed adjacent to the image sensor.

[0196] The effective diameter of each lens may satisfy any one of the following conditions.

[0197] Condition 1: CA_L3, CA_L4, CA_L5, CA_L7>CA_L1>CA_L2, CA_L6

[0198] Condition 2: CA_L1, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7>CA_L2

[0199] Condition 3: CA_L4, CA_L7>CA_L3>CA_L1, CA_L2, CA_L5, CA_L6

[0200] Condition 4: CA_L4>CA_L1, CA_L2, CA_L3, CA_L5, CA_L6, CA_L7

[0201] Condition 5: CA_L3, CA_L4, CA_L7>CA_L5>CA_L1, CA_L2, CA_L6

[0202] Condition 6: CA_L1, CA_L3, CA_L4, CA_L5, CA_L7>CA_L6>CA_L2

[0203] Condition 7: CA_L4>CA_L7>CA_L1, CA_L2, CA_L3, CA_L5, CA_L6

[0204] Regarding the refractive index, the refractive index of the fifth lens (105) can be the highest among the lenses, exceeding 1.6, for example, 1.65. The second lens (102), the fourth lens (104), the sixth lens (106), and the seventh lens (107) can individually or collectively have the lowest refractive index among the lenses. For example, the refractive index of the second lens (102), the sixth lens (106), and the seventh lens (108) can be the smallest among the lenses, less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index can be 0.2 or greater. By providing a lens closest to the object made of a glass material with the highest refractive index, and providing a lens adjacent to the glass material lens and a lens adjacent to the image sensor (500) with a lens made of a plastic material with the lowest refractive index, the incident efficiency can be increased, and the refractive power between the lens made of the glass material and the lens made of the plastic material can be controlled to guide light to the image sensor (500).

[0205] The refractive index of each lens may satisfy any one of the following conditions.

[0206] Condition 1: n5 > n1 > n2, n3, n4, n6, n7

[0207] Condition 2: n1, n3, n5 > n2 = n4 = n6 = n7

[0208] Condition 3: n1, n5 > n3 > n2, n4, n6, n7

[0209] Condition 4: n5 > n1, n2, n3, n4, n6, n7

[0210] When comparing Abbe numbers, the Abbe number of the third lens (103) may be the largest among the lenses and may be 60 or higher. The Abbe number of the fifth lens (105) may be the smallest among the lenses and may be 25 or lower. The difference between the maximum refractive index and the minimum Abbe number may be 40 or higher. By maximizing the Abbe number of the third lens (103) disposed at the center of the optical system (1000) and minimizing the Abbe number of the fifth lens (105) having a low refractive index adjacent to the image sensor (500), dispersion of light passing through lenses made of a glass material and a plastic material may be controlled, and dispersion between lenses made of a glass material and a plastic material may be increased, so that light can be guided to the image sensor (500).

[0211] The Abbe number of each lens may satisfy any one of the following conditions.

[0212] Condition 1: v2, v3, v4, v6, v7 > v1 > v5

[0213] Condition 2: v3 > v2 = v4 = v6 = v7 > v1, v5

[0214] Condition 3: v3 > v1, v2, v4, v5, v6, v7

[0215] Condition 4: v1, v2, v3, v4, v6, v7 > v5

[0216] The focal lengths (F1, F2, F5, F7) of lenses 1, 2, 5, and 7 (101, 102, 105, 107) may have a negative (-) sign. The lenses 1, 2, 5, and 7 (101, 102, 105, 107) may have a negative (-) refractive power. The focal lengths (F3, F4, F6) of the third lens, the fourth lens, and the sixth lens (103, 104, 106) may have a positive (+) sign. The third lens, the fourth lens, and the sixth lens (103, 104, 106) may have a positive (+) refractive power. The sensor side of the first lens (101) and the second lens (102) having negative (-) refractive power may be provided with a third lens (103) having positive (+) refractive power. Thus, light incident from the object side may move away from the optical axis direction and then converge toward the optical axis direction, thereby forming a stable optical path.

[0217] In addition, the fourth lens (104) and the fifth lens (105) adjacent to each other can satisfy the following conditions.

[0218] Condition 1: The refractive index of the lens with positive refractive power is less than the refractive index of the lens with negative refractive power.

[0219] Condition 2: The dispersion value of the lens with positive refractive power > the dispersion value of the lens with negative refractive power

[0220] Here, among the plastic lenses, the fourth lens (104) has positive refractive power, and the fifth lens (105) has negative refractive power. According to conditions 1 and 2, the refractive index of the fourth lens (104) is smaller than the refractive index of the fifth lens (105), and the dispersion value of the fourth lens (104) is larger than the dispersion value of the fifth lens (105). Chromatic aberration occurring in the plastic lens can be corrected using the plastic lens. In addition, when the fourth lens (104) and the fifth lens (105) as continuously arranged plastic lenses satisfy the conditions of a refractive index difference of 0.1 or more and 0.15 or less and an Abbe number difference of 20 or more and 50 or less, chromatic aberration occurring in the plastic lens can be compensated using the plastic lens.

[0221] The optical system exhibits chromatic aberration, which is corrected using two lenses arranged in series or a cemented lens. As the temperature changes from low to high, the lenses repeatedly shrink and expand. Lenses made of the same material exhibit the same change in lens characteristics due to temperature changes, so it is effective to correct chromatic aberration between lenses made of the same material even when the temperature changes. Therefore, in the first embodiment of the present invention, the fourth lens (104) and the fifth lens (105) can be used to correct chromatic aberration occurring in the plastic lens.

[0222] From the optical axis to the effective image area, the maximum distance between the two lenses with the largest Abbe number difference among the two adjacent lenses can be smaller than the maximum distance between other adjacent lens pairs. Here, the distance refers to the distance from the optical axis to the effective diameter area between the two lenses. The two lenses with the largest Abbe number difference among the two adjacent lenses can be the fourth lens (104) and the fifth lens (105). Between the 8th surface (S8) of the sensor side surface of the fourth lens (104) and the 9th surface (S9) of the object side surface of the fifth lens (105), the maximum distance value from the optical axis to the effective diameter area in the direction perpendicular to the optical axis can be smaller than the maximum distance value between any two adjacent lenses. This makes the distance between the two lenses made of plastic materials that are difficult to join smaller, maximizes the Abbe number difference, and thus achieves the effect of reducing chromatic aberration to the same level as the chromatic aberration of the joined lenses even when the lenses are not joined.

[0223] When the focal lengths are compared as absolute values, the focal length of the first lens (101) may be the longest among the lenses and may be 50 or more and 60 or less. The focal length of the sixth lens (106) may be the shortest among the lenses, and the absolute value of the focal length of the seventh lens (106) may be 5 or more and 10 or less.

[0224] Since the first lens (101) has the largest focal length and the weakest refractive power among the lenses, the difference in Abbe number between the second lens (102) and the third lens (103) arranged on the sensor side of the first lens (101) does not need to be very large to achieve the effect of correcting chromatic aberration.

[0225] The absolute value of the focal length of each lens may satisfy any one of the following conditions.

[0226] Condition 1: |f1|>|f2|, |f3|, |f4|, |f5|, |f6|, |f7|

[0227] Condition 2: |f1|>|f2|>|f3|, |f4|, |f5|, |f6|, |f7|

[0228] Condition 3: |f1|, |f2|, |f4|>|f3|>|f5|, |f6|, |f7|

[0229] Condition 4: |f1|, |f2|>|f4|>|f3|, |f5|, |f6|, |f7|

[0230] Condition 5: |f1|, |f2|, |f3|, |f4|, |f7|>|f5|>|f6|

[0231] Condition 6: |f1|, |f2|, |f3|, |f4|, |f5|, |f7|>|f6|

[0232] Condition 7: |f1|, |f2|, |f3|, |f4|>|f7|>|f5|, |f6|

[0233] The thickness (T1) of the first lens (101) may be 1.1 times or greater, for example, in the range of 1.2 times to 1.5 times, the difference between the maximum thickness and the minimum thickness, wherein the center thickness (CT1) is the smallest and the edge thickness (ET1) is the largest. The maximum thickness (T2) of the second lens (102) may be in the range of 1 times to 1.5 times the minimum thickness. The second lens (102) may have a minimum center thickness (CT2) and a maximum edge thickness (ET2). The thickness (T3) of the third lens (103) may be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 1 to 1.5 times the minimum thickness. The thickness (T4) of the fourth lens (104) may be the largest at the center and the smallest at the edge, wherein the maximum thickness is in the range of 2 to 2.5 times the minimum thickness. The thickness (T5) of the fifth lens (105) may be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 1.2 to 1.7 times the minimum thickness. The thickness (T6) of the sixth lens (106) may be maximum at the center and minimum at the edge, wherein the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T7) of the seventh lens (107) may be minimum at the center and maximum at the edge, wherein the maximum thickness is in the range of 1 to 1.5 times the minimum thickness.

[0234] The thickness of each lens may satisfy any one of the following conditions.

[0235] Condition 1: 0.5<CT1 / ET1<1, 1<ET1 / CT1<1.5

[0236] Condition 2: 0.5<CT2 / ET2<1, 1<ET2 / CT2<1.5

[0237] Condition 3: 0.5<CT3 / ET3<1, 1<ET3 / CT3<1.5

[0238] Condition 4: 2<CT4 / ET4<2.5, 0.1<ET4 / CT4<0.5

[0239] Condition 5: 0.5<CT5 / ET5<1, 1.2<ET5 / CT5<1.7

[0240] Condition 6: 1.2<CT6 / ET6<1.7, 0.5<ET6 / CT6<1

[0241] Condition 7: 0.5<CT7 / ET7<1, 1<ET7 / CT7<1.5

[0242] Condition 8: 1<ΣCT / ΣET<1.2, 0.5<ΣET / ΣCT<1

[0243] Among the gaps (G1 to G7) between the lenses, the first gap (G1) between the first lens (101) and the second lens (102) may have a maximum value at the center and a minimum value at the edge. The second gap (G2) between the second lens (102) and the third lens (103) may have a minimum value at the center and a maximum value at the edge. The third gap (G3) between the third lens (103) and the fourth lens (104) may have a maximum value at the edge and a minimum value at the center. The fourth gap (G4) between the fourth lens (104) and the fifth lens (105) may have a minimum value at the center and a maximum value at the edge. The fifth gap (G5) between the fifth lens (105) and the sixth lens (106) may have a maximum value at the center portion and a minimum value at the edge portion. The sixth gap (G6) between the sixth lens (106) and the seventh lens (107) may have a minimum value at the center portion and a maximum value at the edge portion.

[0244] Figure 6 、 Figure 8 and Figure 10 are shown separately Figure 1 The graphs show the diffraction MTF (Modulation Transfer Function) of the optical system at room temperature, low temperature and high temperature. These graphs show the modulation (brightness ratio) as a function of spatial frequency. Figure 6 、 Figure 8 and Figure 10 As shown, in the first embodiment of the present invention, the deviation of the MTF between room temperature and low temperature or high temperature can be less than 10%, that is, 7% or less.

[0245] Figure 7 、 Figure 9 and Figure 11 It shows Figure 1 Graphs showing aberration characteristics of an optical system at room temperature, low temperature, and high temperature. Figure 7 、 Figure 9 and Figure 11 The aberration curve diagram in FIG shows the measured values ​​of spherical aberration (longitudinal spherical aberration), astigmatism field curve (Astigmatic Field Curve) and distortion (Distortion) from left to right. Figure 7 、 Figure 9 and Figure 11 In FIG, the X-axis represents focal length (mm) and distortion percentage, and the Y-axis represents image height. In addition, the graph for spherical aberration corresponds to light in the wavelength bands of approximately 435 nm, 486 nm, 546 nm, 587 nm, and 656 nm, while the graph for astigmatism field curve and distortion corresponds to light in the wavelength band of approximately 546 nm. Figure 7 、 Figure 9 and Figure 11 In the aberration diagram of , the closer the curves at room temperature, low temperature, and high temperature are to the Y-axis, the better the aberration correction function is explained. The optical system (1000) according to the first embodiment shows that the measured values ​​are adjacent to the Y-axis in almost all areas. In other words, the optical system (1000) according to the first embodiment has improved resolution and can provide good optical performance not only in the center of the field of view (FOV) but also in the peripheral area. Here, low temperature may refer to -20°C or lower, for example, -20°C to -40°C, room temperature may refer to 22°C±5°C or 18°C ​​to 27°C, and high temperature may refer to 85°C or higher, for example, 85°C to 105°C. Therefore, as Figure 7 、 Figure 9 and Figure 11 As shown, it can be seen that the brightness modulation from low temperature to high temperature decreases by less than 10%, such as 5% or less, or remains almost unchanged.

[0246] Table 3 compares changes in optical characteristics such as EFL, BFL, f-number (F#), TTL, and field of view (FOV_D) in the optical system according to the first embodiment. It can be seen that the rate of change in optical characteristics at low temperatures relative to room temperature is 5% or less, for example, 3% or less. Furthermore, the rate of change in optical characteristics at low temperatures relative to room temperature is 5% or less, for example, 3% or less.

[0247] [Table 3]

[0248] Room temperature Low temperature high temperature Low temperature / room temperature High temperature / room temperature EFL(F) 10.88 10.79 10.99 99.17％ 101.01％ BFL 3.42 3.41 3.42 99.70％ 100.00％ F# 1.64 1.63 1.66 99.39％ 101.21％ TTL 29.99 29.92 30.08 99.76％ 100.30％ FOV_D 54.69 55.19 54.10 100.91％ 98.92％

[0249] Therefore, as shown in Table 3, it can be seen that the rate of change in optical characteristics, such as effective focal length (EFL), TTL, BFL, f-number, and field of view (FOV_D), due to temperature change from low to high temperatures is 10% or less, that is, 5% or less, for example, within the range of 0 to 5%. This design allows temperature compensation of plastic lenses even when using one or more plastic lenses, thereby preventing a decrease in the reliability of optical characteristics.

[0250] The optical system disclosed in the first embodiment can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and achieve good optical performance not only in the central portion of the field of view (FOV) but also in the peripheral portion.

[0251] An optical system according to a second embodiment of the present invention will now be described.

[0252] Figure 13 is a side sectional view of an optical system and an image pickup device module including the optical system according to a second embodiment, Figure 14 It shows Figure 13 Table of aspheric coefficients of lenses in optical systems, Figure 15 It shows Figure 13 A table showing the thickness of each lens in the optical system and the gaps between adjacent lenses. Figure 16 It shows Figure 13 Table of sag values ​​of the lens surfaces of the first lens to the seventh lens in the optical system, Figure 17 It shows Figure 13 Table of the inclination angles of the lens surfaces of the first lens to the seventh lens in the optical system, Figure 18 It shows Figure 13 The graph of the diffraction MTF (Modulation Transfer Function) data of the optical system shown at room temperature is shown in FIG. Figure 19 It shows Figure 13 The graph of the aberration characteristics of the optical system shown at room temperature is shown in FIG. Figure 20 It shows Figure 13 The graph of the diffraction MTF data of the optical system shown at low temperature is Figure 21 It shows Figure 13 The graph of aberration characteristics of the optical system at low temperatures is shown in FIG. Figure 22 It shows Figure 13 The diffraction MTF curve of the optical system at high temperature is shown in the figure. Figure 23 It shows Figure 13 The aberration characteristics of the optical system at high temperature are shown in the graph, and Figure 24 It shows Figure 13 A graph showing the peripheral light intensity ratio of the optical system shown.

[0253] Reference Figure 13 The optical system (1100) may include a lens unit, and the lens unit may include a first lens (201) to a seventh lens (207). The first lens to the seventh lens (201 to 207) may be sequentially arranged along an optical axis (OA) of the optical system (1100). Light corresponding to information of an object may pass through the first lens (201) to the seventh lens (207) and the filter (600) and enter the image sensor (500).

[0254] The first lens (201) may be arranged closest to the object side. The first lens (201) may be arranged farthest from the sensor side. The first lens (201) may have a negative (-) refractive power relative to the optical axis (OA). The first lens (201) may include a plastic material or a glass material, for example, it may be made of glass. The first lens (201) made of glass can reduce changes in the center position and the curvature radius caused by temperature changes caused by the surrounding environment, and can protect the incident side surface of the optical system (1100).

[0255] Based on the optical axis, the object side first surface (S1) of the first lens (201) may be convex, and the sensor side second surface (S2) may be concave. The first lens (201) may have a convex meniscus shape on the object side. The first lens (201) may have a concave meniscus shape on the sensor side. The first lens (201) may be made of a glass material and may have an aspherical surface. At least one or both of the first surface (S1) and the second surface (S2) may be aspherical. The aspheric coefficients of the first surface and the second surface (S1, S2) may be as follows Figure 14 At least one or both of the first surface (S1) and the second surface (S2) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0256] Due to the refractive properties of the first lens (201), the second lens (202) can be spaced further apart from the first lens (201). In other words, the center gap between the first lens (201) and the second lens (202) can be the largest within the lens unit.

[0257] The refractive index (n1) of the first lens (201) may satisfy the condition n1>1.6 or n1>1.62. When the refractive index (n1) of the first lens (201) satisfies the above condition, the curvature radius of the first lens and the second lens (201, 202) can be increased, thereby making lens manufacturing easier. If the refractive index (n1) of the first lens (201) is less than the condition, the refractive power of the first lens and the second lens (201, 202) must be increased by forming a sharply concave or convex lens surface, which makes lens manufacturing difficult, increases the defect rate, and may lead to a decrease in the yield rate.

[0258] The second lens (202) may be arranged second from the object side. The second lens (202) may be arranged sixth from the sensor side. The second lens (202) may be arranged between the first lens (201) and the third lens (203). The second lens (202) may have a negative (-) refractive power on the optical axis (OA). The second lens (202) may include a plastic or glass material. For example, the second lens (202) may be provided as a plastic material.

[0259] Based on the optical axis (OA), the object side third surface (S3) of the second lens (202) may be concave, and the sensor side fourth surface (S4) may be convex. The second lens (202) may have a convex meniscus shape toward the sensor side. The second lens (202) may have a concave meniscus shape on the object side. The second lens (202) may be made of a plastic material and may be aspherical. At least one or both of the third surface (S3) and the fourth surface (S4) may be aspherical. The aspheric coefficients of the third surface and the fourth surface (S3, S4) may be as follows Figure 14 At least one or both of the third surface (S3) and the fourth surface (S4) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0260] An aperture (stop) can be provided around the periphery of the sensor-side fourth surface (S4) of the second lens (202). An aperture (stop) can be provided around the periphery of the sensor-side fifth surface (S5) of the third lens (203). This aperture can reduce the TTL within the field of view and achieve miniaturization of the optical system. Therefore, it is possible to prevent a decrease in the weight-based yield (yield by weight) of the optical system and improve production efficiency. In addition, by reducing the TTL within the horizontal field of view (FOV_H) of 40 degrees to 50 degrees, the optical system can be miniaturized.

[0261] The third lens (203) may be provided as the third lens on the object side. The third lens (203) may be provided as the fifth lens from the sensor side. The third lens (203) may be provided between the second lens (202) and the fourth lens (204). The third lens (203) may have a positive (+) refractive power along the optical axis (OA). The third lens (203) may include a plastic or glass material. For example, the third lens (203) may be provided as a glass material.

[0262] The object-side fifth surface (S5) of the third lens (203) may be convex relative to the optical axis (OA), and the sensor-side sixth surface (S6) may be convex. The third lens (203) may have a shape in which both surfaces are convex. The third lens (203) may be made of a glass material and may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be arranged so as not to have a critical point from the optical axis (OA) to the end of the effective area.

[0263] The fourth lens (204) may be arranged fourth from the object side. The fourth lens (204) may be arranged fourth from the sensor side. The fourth lens (204) may be arranged between the third lens (203) and the fifth lens (205). The fourth lens (204) may have positive (+) or negative (-) refractive power on the optical axis (OA). The fourth lens (204) may have positive (+) refractive power. The fourth lens (204) may include a plastic or glass material. For example, the fourth lens (204) may be provided as a plastic material.

[0264] Based on the optical axis, the object-side seventh surface (S7) of the fourth lens (204) may be convex, and the sensor-side eighth surface (S8) may be convex. The fourth lens (204) may have a convex meniscus shape on the object side. The fourth lens (204) may have a concave meniscus shape on the sensor side. The fourth lens (204) may be made of a plastic material and may be aspherical. At least one or both of the seventh surface (S7) and the eighth surface (S8) may be aspherical. The aspheric coefficients of the seventh surface and the eighth surface (S7, S8) may be as follows Figure 14 At least one or both of the seventh surface (S7) and the eighth surface (S8) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0265] The fifth lens (205) may be provided as the fifth lens from the object side. The fifth lens (205) may be provided as the third lens from the sensor side. The fifth lens (205) may be provided between the fourth lens (204) and the sixth lens (206). The fifth lens (205) may have positive (+) or negative (-) refractive power along the optical axis (OA). The fifth lens (205) may have negative (-) refractive power. The fifth lens (205) may include a plastic or glass material. For example, the fifth lens (205) may be provided as a plastic material.

[0266] The fifth lens (205) may have a ninth surface (S9) that is convex on the object side and a tenth surface (S10) that is concave on the sensor side relative to the optical axis (OA). The fifth lens (205) may have a convex meniscus shape on the object side. The fifth lens (205) may have a concave meniscus shape on the sensor side. The fifth lens (205) may be made of a plastic material and may be aspherical. At least one or both of the ninth surface (S9) and the tenth surface (S10) may be aspherical. The aspheric coefficients of the ninth surface and the tenth surface (S9, S10) may be as follows Figure 14 At least one or both of the ninth surface (S9) and the tenth surface (S10) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0267] The sixth lens (206) may be provided as the sixth lens from the object side. The sixth lens (206) may be provided as the second lens from the sensor side. The sixth lens (206) may be provided between the fifth lens (205) and the seventh lens (207). The sixth lens (206) may have positive (+) or negative (-) refractive power relative to the optical axis (OA). The sixth lens (206) may have positive (+) refractive power. The sixth lens (206) may include a plastic or glass material. For example, the sixth lens (206) may be provided as a plastic material.

[0268] The sixth lens (206) may have an 11th surface (S11) convex on the object side and a 12th surface (S12) convex on the sensor side relative to the optical axis (OA). The sixth lens (206) may have a shape in which both surfaces are convex. The sixth lens (206) may be made of a plastic material and may be aspherical. At least one or both of the 11th surface (S11) and the 12th surface (S12) may be aspherical. The aspherical coefficients of the 11th surface and the 12th surface (S11, S12) may be as follows: Figure 14 Available in S1 and S2 of L6.

[0269] The 11th surface (S11) of the 6th lens (106) can be configured to have no critical point from the optical axis (OA) to the end of the effective area. The 12th surface (S12) of the 6th lens (106) can include a critical point from the optical axis (OA) to the end of the effective area. When the 12th surface (S12) has a critical point, the critical point can be located in the range of 85% to 90% of the effective radius (r62) from the optical axis (OA), preferably in the range of 86% to 89%. The critical point of the 12th surface (S12) can be located in the range of 3.5 mm to 4 mm from the optical axis (OA), preferably in the range of 3.8 mm to 3.9 mm.

[0270] The seventh lens (207) may be disposed farthest from the object side. The seventh lens (207) may be disposed closest to the image sensor (500). The seventh lens (207) may have positive (+) or negative (-) refractive power relative to the optical axis (OA). The seventh lens (207) may have negative (-) refractive power. The seventh lens (207) may include a plastic or glass material. For example, the seventh lens (207) may be provided as a plastic material.

[0271] The seventh lens (207) may have a convex 13th surface (S13) on the object side and a concave 14th surface (S14) on the sensor side based on the optical axis (OA). The seventh lens (207) may have a convex meniscus shape on the object side. The seventh lens (207) may have a concave meniscus shape on the sensor side. At least one or both of the 13th surface (S13) and the 14th surface (S14) may be aspherical. The aspheric coefficients of the 13th surface and the 14th surface (S13, S14) may be given by Figure 14 Available in S13 and S14 of L7.

[0272] The 13th surface (S13) of the 7th lens (207) may extend from the optical axis (OA) to the end of the effective area including a critical point. If the 13th surface (S13) has a critical point, the critical point may be located in the range of 40% to 50% of the effective radius (r71) from the optical axis (OA), preferably in the range of 44% to 47%. The critical point of the 13th surface (S13) may be located in the range of 1.8 mm to 2.2 mm from the optical axis (OA), preferably in the range of 1.9 mm to 2 mm. The 14th surface (S14) of the 7th lens (207) may extend from the optical axis (OA) to the end of the effective area including a critical point. If the 14th surface (S14) has a critical point, the critical point may be located in the range of 50% to 60% of the effective radius (r72) from the optical axis (OA), preferably in the range of 54% to 56%. The critical point of the 14th surface (S14) may be located within a range of 2.5 mm to 3 mm, preferably within a range of 2.7 mm to 2.8 mm, from the optical axis (OA).

[0273] The seventh lens (207) may be a plastic lens that is closest to the image sensor (500). In addition, by arranging two or more plastic lenses adjacent to the image sensor (500), it is possible to improve induced aberrations such as spherical aberration and chromatic aberration by having a lens surface with an aspherical shape, and to control resolution. In addition, by arranging the plastic lens as a lens adjacent to the image sensor (500), it is possible to be less sensitive to assembly tolerances than glass lenses. In other words, being less sensitive to assembly tolerances means that even if the assembly differs slightly from the design during assembly, the optical performance may not be significantly affected. In addition, by providing the two lenses (206, 207) adjacent to the image sensor (500) with a plastic material, it is possible to improve optical performance by, for example, improving aberration characteristics and preventing resolution degradation by having an aspherical lens surface.

[0274] [Table 4]

[0275]

[0276]

[0277] Table 4 shows the surface number (Surface), curvature radius (Radius), center thickness of each lens or distance between lens surfaces (Thickness), refractive index (Index, nd), Abbe number (Abbe, vd), effective radius (Semi Aperture), and focal length (Focal length) of the lenses according to the second embodiment of the present invention. Here, the unit of the curvature radius and thickness or distance may be mm.

[0278] [Table 5]

[0279] item value item value F 10.8634 F-number 1.6400 ET1 2.4636 FOV_H 46.00 ET2 4.5362 EPD 6.6241 ET3 2.0000 BFL 3.3752 ET4 2.0000 TD 26.6249 ET5 3.6250 IhD 5.1450 ET6 2.0000 SD 18.2679 ET7 2.3358 TTL 30.0000 ΣIndex 11.0760 GLca_Aver 10.361 ΣAbbe 363.1005 PLca_Aver 9.836 ΣCT 20.9912 CT_max 4.0066 ΣCG 5.6336 CT_min 2.0000 CA_max 11.727 CT_Aver 2.9987 CA_min 8.634 F_LG1 -21.283 CA_Aver 9.896 F_LG2 8.866

[0280] Table 5 shows the values ​​of each item in the above mathematical formula of the optical system (1100) of the embodiment. The optical system (1100) may include a total track length (TTL) (mm), a back focal length (BFL), an effective focal length (F) (mm), an image height (ImgH) (mm), an effective diameter (CA) (mm), a thickness (mm), a TTL (mm), an optical axis distance from the first surface (S1) to the twelfth surface (S12) (TD (mm)), a sum of refractive indices, a sum of Abbe numbers, a sum of thicknesses (mm), a sum of distances 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 (FOV_H) (degrees), an edge thickness (ET), an aperture number, and the like.

[0281] The center thicknesses of the first to seventh lenses (201 to 207) are indicated as CT1 to CT7, the edge thicknesses at the ends of the effective areas of each lens are indicated as ET1 to ET7, the center gaps between adjacent lenses are indicated as CG1 to CG6, and the edge gaps between the edges of each lens are indicated as EG1 to EG6. The back focus (BFL) is the optical axis distance from the image sensor (500) to the center of the last lens. The TTL is the optical axis distance from the center of the first surface (S1) of the first lens (201) to the image surface of the image sensor (500).

[0282] like Figure 14 As shown, the lens surfaces of the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens (201, 202, 204, 205, 206, 207) in the lens unit of the second embodiment may include aspheric surfaces having a 30th-order aspheric coefficient. For example, the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens (201, 202, 204, 205, 206, 207) may include lens surfaces having a 30th-order aspheric coefficient. As described above, the aspheric surface having a 30th-order aspheric coefficient (a non-zero value) can significantly change the aspheric shape in the peripheral region, thereby effectively correcting the optical performance in the peripheral region of the field of view (FOV).

[0283] The thicknesses (T1 to T7) of the first to seventh lenses (201 to 207) and the gaps (G1 to G6) between adjacent lenses may be set. Figure 3 As shown, the thickness of each lens in the Y-axis direction (T1 to T7) can be displayed with a gap of 0.1 mm or 0.2 mm or larger, and the gap between each lens (G1 to G6) can be displayed with a gap of 0.1 mm or 0.2 mm or larger.

[0284] When comparing the absolute values ​​of the radii of curvature of each lens, the radius of curvature of the first surface (S1) of the first lens (201) on the optical axis (OA) may be the largest among the lenses, and the radius of curvature of the tenth surface (S10) of the fifth lens (205) may be the smallest among the lenses. The difference between the maximum radius of curvature and the minimum radius of curvature may be three times or more, for example, in the range of three times to five times.

[0285] Among the object-side surfaces and sensor-side surfaces of the first to seventh lenses (201 to 207), the number of lens surfaces having a radius of curvature greater than 40 may be one or more but not more than four. This allows the radius of curvature of the lenses constituting the optical system (1100) to be designed to be mostly small, thereby satisfying the field of view, focal length, and total length of the lenses when they are installed in a vehicle.

[0286] 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 stronger refractive power to refract light through the plastic lens. In addition, in order to increase the refractive power, the curvature radius of the lens surface can be smaller.

[0287] The absolute value of the radius of curvature of the first surface (S1) of the first lens (201) may be greater than the absolute value of the radius of curvature of the second surface (S2). The absolute value of the radius of curvature of the third surface (S3) of the second lens (202) may be smaller than the absolute value of the radius of curvature of the fourth surface (S4). The absolute value of the radius of curvature of the fifth surface (S5) of the third lens (203) may be greater than the absolute value of the radius of curvature of the sixth surface (S6). The absolute value of the radius of curvature of the seventh surface (S7) of the fourth lens (204) may be smaller than the absolute value of the radius of curvature of the eighth surface (S8). The absolute value of the radius of curvature of the ninth surface (S9) of the fifth lens (205) may be greater than the absolute value of the radius of curvature of the tenth surface (S10). The absolute value of the radius of curvature of the eleventh surface (S11) of the sixth lens (206) may be smaller than the absolute value of the radius of curvature of the twelfth surface (S12). The absolute value of the curvature radius of the 13th surface (S13) of the 7th lens (207) may be greater than the absolute value of the curvature radius of the 14th surface (S14).

[0288] The ratio of the curvature radius of each lens may satisfy the following conditions.

[0289] Condition 1: 3<|L1R1 / L1R|<4

[0290] Condition 2: 0.5<|L2R1 / L2R2|<1

[0291] Condition 3: 1.5<|L3R1 / L3R2|<2

[0292] Condition 4: 0.1<|L4R1 / L4R2|<0.5

[0293] Condition 5: 5<|L5R1 / L5R2|<10

[0294] Condition 6: 0.1<|L6R1 / L6R2|<0.5

[0295] Condition 7: 1<|L7R1 / L7R2|<1.5

[0296] When describing the center thickness (CT) of the lens based on the optical axis, the center thickness (CT4) of the fourth lens (204) may be the largest among the lenses, and the center thickness (CT1, CT5, CT7) of at least one of the first lens (201), the fifth lens (205), and the seventh lens (207) may be the smallest among the lenses. The difference between the maximum center thickness and the minimum center thickness of the lens may be within a range of 2 mm or more and 2.5 mm or less.

[0297] The center thickness of each lens may satisfy any one of the following conditions.

[0298] Condition 1: CT2, CT3, CT4, CT6 > CT1 = CT5 = CT7

[0299] Condition 2: CT4 > CT2 > CT1, CT3, CT5, CT6, CT7

[0300] Condition 3: CT2, CT4 > CT3 > CT1, CT5, CT6, CT7

[0301] Condition 4: CT4 > CT1, CT2, CT3, CT6, CT7

[0302] Condition 5: CT2, CT3, CT4 > CT6 > CT1, CT5, CT7

[0303] The center gaps (CG) between the lenses are described as follows: the center gap (CG1) between the first lens (201) and the second lens (202) may be the largest, and the center gap (CG4) between the fourth lens (204) and the fifth lens (205) may be the smallest. The difference between the largest center gap and the smallest center gap among the spaced lenses may be 3 mm or greater, for example, in the range of 3 mm to 4 mm.

[0304] The center gap between each lens can satisfy the following conditions.

[0305] Condition 1: CG1 > CG2, CG3, CG4, CG5, CG6

[0306] Condition 2: CG1, CG5, CG6 > CG2 > CG3, CG4

[0307] Condition 3: CG1, CG2, CG5, CG6 > CG3 > CG4

[0308] Condition 4: CG1, CG2, CG3, CG5, CG6 > CG4

[0309] Condition 5: CG1, CG6 > CG5 > CG2, CG3, CG4

[0310] ※Condition 6: CG1>CG6>CG2、CG3、CG4、CG5

[0311] Regarding the effective diameter, the lens with the largest effective diameter may be a lens made of a glass material. The lens with the largest effective diameter may be the fourth lens (204). 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 with the largest effective diameter may be the seventh surface (S7) of the fourth lens (204). The lens with the smallest effective diameter may be the second lens (202). The lens surface with the smallest effective diameter may be the fourth surface (S4) of the second lens (202). The effective diameter of the plastic lens may be smaller than the effective diameter of the glass lens. The plastic lens may be disposed adjacent to the image sensor.

[0312] The effective diameter of each lens may satisfy any one of the following conditions.

[0313] Condition 1: CA_L3, CA_L4>CA_L1>CA_L2, CA_L5, CA_L6, CA_L7

[0314] Condition 2: CA_L1, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7>CA_L2

[0315] Condition 3: CA_L4>CA_L3>CA_L1, CA_L2, CA_L5, CA_L6, CA_L7

[0316] Condition 4: CA_L4>CA_L1, CA_L2, CA_L3, CA_L5, CA_L6, CA_L7

[0317] Condition 5: CA_L1, CA_L3, CA_L4>CA_L5>CA_L2, CA_L6, CA_L7

[0318] Condition 6: CA_L1, CA_L3, CA_L4, CA_L5, CA_L7>CA_L6>CA_L2

[0319] Condition 7: CA_L1, CA_L3, CA_L4, CA_L5>CA_L7>CA_L2, CA_L6

[0320] Regarding the refractive index, the refractive index of the fifth lens (205) can be the highest among the lenses, exceeding 1.6, for example, exceeding 1.65. The second lens (202), the fourth lens (204), the sixth lens (206), and the seventh lens (207) can individually or collectively have the lowest refractive index among the lenses. For example, the refractive index of the second lens (202), the sixth lens (206), and the seventh lens (108) can be the lowest among the lenses, less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index can be 0.2 or greater. By providing a lens closest to the object made of a glass material with the highest refractive index, and providing a lens adjacent to the glass material lens and a lens adjacent to the image sensor (500) with a lens made of a plastic material with a low refractive index, the incident efficiency can be increased, and the refractive power between the lenses made of the glass material and the plastic material can be controlled to guide light to the image sensor (500).

[0321] The refractive index of each lens may satisfy any one of the following conditions.

[0322] Condition 1: n5 > n1 > n2, n3, n4, n6, n7

[0323] Condition 2: n1, n3, n5 > n2 = n4 = n6 = n7

[0324] Condition 3: n1, n5 > n3 > n2, n4, n6, n7

[0325] Condition 4: n5 > n1, n2, n3, n4, n6, n7

[0326] When comparing Abbe numbers, the Abbe number of the third lens (203) may be the largest among the lenses and may be 60 or higher. The Abbe number of the fifth lens (205) may be the smallest among the lenses and may be 25 or lower. The difference between the maximum refractive index and the minimum Abbe number may be 40 or higher. By maximizing the Abbe number of the third lens (203) disposed at the center portion of the optical system (1100) and minimizing the Abbe number of the fifth lens (205) having a low refractive index adjacent to the image sensor (500), dispersion of light passing through lenses made of a glass material and a plastic material may be controlled, and dispersion between lenses made of a glass material and a plastic material may be increased, so that light can be guided to the image sensor (500).

[0327] The Abbe number of each lens may satisfy any one of the following conditions.

[0328] Condition 1: v2, v3, v4, v6, v7 > v1 > v5

[0329] Condition 2: v3 > v2 = v4 = v6 = v7 > v1, v5

[0330] Condition 3: v3 > v1, v2, v4, v5, v6, v7

[0331] Condition 4: v1, v2, v3, v4, v6, v7 > v5

[0332] The focal lengths (F1, F2, F5, F7) of the first lens, the second lens, the fifth lens, and the seventh lens (201, 202, 205, 207) may have a negative (-) sign. The first lens, the second lens, the fifth lens, and the seventh lens (201, 202, 205, 207) may have a negative (-) refractive power. The focal lengths (F3, F4, F6) of the third lens, the fourth lens, and the sixth lens (203, 204, 206) may have a positive (+) sign. The third lens, the fourth lens, and the sixth lens (203, 204, 206) may have a positive (+) refractive power. The sensor side of the first lens (201) and the second lens (202) having negative (-) refractive power may be provided with a third lens (203) having positive (+) refractive power. Thus, light incident from the object side can move away from the optical axis direction and then converge toward the optical axis direction, thereby forming a stable optical path.

[0333] In addition, the fourth lens (204) and the fifth lens (205) adjacent to each other can satisfy the following conditions.

[0334] Condition 1: The refractive index of the lens with positive refractive power is less than the refractive index of the lens with negative refractive power.

[0335] Condition 2: The dispersion value of the lens with positive refractive power > the dispersion value of the lens with negative refractive power

[0336] Here, among the plastic lenses, the fourth lens (204) has positive refractive power, and the fifth lens (205) has negative refractive power. According to conditions 1 and 2, the refractive index of the fourth lens (204) can be smaller than the refractive index of the fifth lens (205), and the dispersion value of the fourth lens (204) can be larger than the dispersion value of the fifth lens (205). Chromatic aberration occurring in the plastic lens can be corrected using the plastic lens. In addition, when the fourth lens (204) and the fifth lens (205) as continuously arranged plastic lenses satisfy the conditions of a refractive index difference of 0.1 or more and 0.15 or less and an Abbe number difference of 20 or more and 50 or less, chromatic aberration occurring in the plastic lens can be compensated using the plastic lens.

[0337] The optical system exhibits chromatic aberration, which is corrected using two lenses arranged in series or a cemented lens. As the temperature changes from low to high, the lenses repeatedly shrink and expand. Lenses made of the same material exhibit the same change in lens characteristics due to temperature changes, so correcting chromatic aberration between lenses made of the same material is effective even when the temperature changes. Therefore, in the second embodiment of the present invention, the fourth lens (204) and the fifth lens (205) can be used to correct chromatic aberration occurring in the plastic lens.

[0338] From the optical axis to the effective aperture area, the maximum distance between two adjacent lenses with the largest Abbe number difference can be smaller than the maximum distance between other adjacent lenses. Here, the distance refers to the distance from the optical axis to the effective diameter area between the two lenses. The two lenses with the largest Abbe number difference among the two adjacent lenses can be the fourth lens (204) and the fifth lens (205). Between the 8th surface (S8) of the sensor side surface of the fourth lens (204) and the 9th surface (S9) of the object side surface of the fifth lens (205), the maximum distance value from the optical axis to the effective diameter area in the direction perpendicular to the optical axis can be smaller than the maximum distance value between any two adjacent lenses. This makes the distance between the two lenses made of plastic materials that are difficult to join smaller, maximizes the Abbe number difference, and achieves the same chromatic aberration reduction effect as the joined lenses even when the lenses are not joined.

[0339] When the focal lengths are compared as absolute values, the focal length of the seventh lens (207) may be the longest among the lenses and may be between 50 and 60. The focal length of the fifth lens (205) may be the shortest among the lenses, and the absolute value of the focal length of the seventh lens (205) may be between 8 and 12.

[0340] The absolute value of the focal length of each lens may satisfy any one of the following conditions.

[0341] Condition 1: |f7|>|f1|>|f2|, |f3|, |f4|, |f5|, |f6|

[0342] Condition 2: |f1|, |f7|>|f2|>|f3|, |f4|, |f5|, |f6|

[0343] Condition 3: |f1|, |f2|, |f4|, |f6|, |f7|>|f3|>|f5|

[0344] Condition 4: |f1|, |f2|, |f7|>|f4|>|f3|, |f5|, |f6|

[0345] Condition 5: |f1|, |f2|, |f3|, |f4|, |f6|, |f7|>|f5|

[0346] Condition 6: |f1|, |f2|, |f4|, |f7|>|f6|>|f3|, |f5|

[0347] Condition 7: |f7|>|f1|, |f2|, |f3|, |f4|, |f5|, |f6|

[0348] The thickness (T1) of the first lens (201) may be 1.1 times or greater of the difference between the maximum thickness and the minimum thickness, for example, in the range of 1.2 times to 1.5 times, wherein the center thickness (CT1) is the smallest and the edge thickness (ET1) is the largest. The maximum thickness (T2) of the second lens (202) may be in the range of 1 times to 1.5 times the minimum thickness. The second lens (202) may have a maximum center thickness (CT2) and a minimum edge thickness (ET2). The thickness (T3) of the third lens (203) may be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 1 to 1.5 times the minimum thickness. The thickness (T4) of the fourth lens (204) may be the largest at the center and the smallest at the edge, wherein the maximum thickness is in the range of 2 to 2.5 times the minimum thickness. The thickness (T5) of the fifth lens (205) may be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 1.2 to 1.7 times the minimum thickness. The thickness (T6) of the sixth lens (206) may be maximum at the center and minimum at the edge, wherein the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T7) of the seventh lens (207) may be minimum at the center and maximum at the edge, wherein the maximum thickness is in the range of 1 to 1.5 times the minimum thickness.

[0349] The thickness of each lens may satisfy any one of the following conditions.

[0350] Condition 1: 0.5<CT1 / ET1<1, 1.5<ET1 / CT1<2

[0351] Condition 2: 1<CT2 / ET2<1.5, 0.5<ET2 / CT2<1

[0352] Condition 3: 0.5<CT3 / ET3<1, 1<ET3 / CT3<1.5

[0353] Condition 4: 2<CT4 / ET4<2.5, 0.1<ET4 / CT4<0.5

[0354] Condition 5: 0.5<CT5 / ET5<1, 1.2<ET5 / CT5<1.7

[0355] Condition 6: 1.2<CT6 / ET6<1.7, 0.5<ET6 / CT6<1

[0356] Condition 7: 0.5<CT7 / ET7<1, 1<ET7 / CT7<1.5

[0357] Condition 8: 1<ΣCT / ΣET<1.2, 0.5<ΣET / ΣCT<1

[0358] Among the gaps (G1 to G7) between the lenses, the first gap (G1) between the first lens (201) and the second lens (202) may have a maximum value at the center and a minimum value at the edge. The second gap (G2) between the second lens (202) and the third lens (203) may have a minimum value at the center and a maximum value at the edge. The third gap (G3) between the third lens (203) and the fourth lens (204) may have a maximum value at the edge and a minimum value at the center. The fourth gap (G4) between the fourth lens (204) and the fifth lens (205) may have a minimum value at the center and a maximum value at the edge. The fifth gap (G5) between the fifth lens (205) and the sixth lens (206) may have a maximum value at the center portion and a minimum value at the edge portion. The sixth gap (G6) between the sixth lens (206) and the seventh lens (207) may have a minimum value at the center portion and a maximum value at the edge portion.

[0359] Figure 18 、 Figure 20 and Figure 22 It shows Figure 13 Graphs of the diffraction MTF (Modulation Transfer Function) at room temperature, low temperature, and high temperature in an optical system of FIG. 3 are graphs showing the modulation as a function of spatial frequency. Figure 18 、 Figure 20 and Figure 22 As shown, in the second embodiment of the present invention, the deviation of the MTF between the low temperature and the high temperature relative to the room temperature may be less than 10%, ie, 7% or less.

[0360] Figure 19 、 Figure 21 and Figure 23 It shows Figure 13 Graphs showing aberration characteristics of an optical system at room temperature, low temperature, and high temperature. Figure 19 、 Figure 21 and Figure 23 The aberration curve diagram in FIG shows the measured values ​​of spherical aberration (longitudinal spherical aberration), astigmatism field curve (Astigmatic Field Curve) and distortion (Distortion) from left to right. Figure 19 、 Figure 21 and Figure 23 In FIG, the X-axis represents focal length (mm) and distortion (%), and the Y-axis represents image height (height). In addition, the graph for spherical aberration corresponds to light in the wavelength bands of approximately 435 nm, 486 nm, 546 nm, 587 nm, and 656 nm, and the graph for astigmatism field curve and distortion corresponds to light in the wavelength band of approximately 546 nm. Figure 19 、 Figure 21 and Figure 23 In the aberration diagram of , the closer the curves at room temperature, low temperature, and high temperature are to the Y-axis, the better the aberration correction function is explained. The optical system (1100) according to the second embodiment shows that the measured values ​​are adjacent to the Y-axis in almost all areas. Therefore, the optical system (1100) according to the second embodiment has improved resolution and can achieve good optical performance not only in the central part of the field of view (FOV) but also in the peripheral area. Here, low temperature may refer to a temperature of -20 degrees Celsius or lower, for example, -20 to -40 degrees Celsius, room temperature may refer to a range of 22 degrees Celsius ± 5 degrees Celsius or 18 to 27 degrees Celsius, and high temperature may refer to a temperature of 85 degrees Celsius or higher, for example, 85 to 205 degrees Celsius. Therefore, as Figure 19 、 Figure 21 and Figure 23 As shown, it can be seen that the brightness modulation from low temperature to high temperature decreases by less than 10%, such as 5% or less, or remains almost unchanged.

[0361] Table 6 compares changes in optical characteristics, such as EFL, BFL, f-number (F#), TTL, and field of view (FOV_D), at room temperature, low temperature, and high temperature in the optical system according to the first embodiment. It can be seen that the rate of change in optical characteristics at low temperature is 5% or less, for example, 3% or less, compared to room temperature. It can be observed that the rate of change in optical characteristics at low temperature is 5% or less, for example, 3% or less, compared to room temperature.

[0362] [Table 6]

[0363]

[0364]

[0365] Therefore, as shown in Table 6, it can be seen that the change in optical characteristics due to temperature change from low temperature to high temperature (for example, the rate of change of effective focal length (EFL), TTL, BFL, f-number, and field of view (FOV_D)) is 10% or less, that is, 5% or less, for example, within the range of 0 to 5%. This design allows temperature compensation of the plastic lens even when using one or more plastic lenses, thereby preventing a decrease in the reliability of the optical characteristics.

[0366] The optical system disclosed in the first embodiment can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and achieve good optical performance not only in the central portion of the field of view (FOV) but also in the peripheral portion.

[0367] An optical system according to a third embodiment of the present invention will now be described.

[0368] Figure 25 is a cross-sectional view of an optical system and an image pickup device module including the optical system according to a third embodiment, Figure 26 It shows Figure 25 Table of aspheric coefficients of lenses in optical systems, Figure 27 It shows Figure 25 A table showing the thickness of each lens in the optical system and the gaps between adjacent lenses. Figure 28 It shows Figure 25 Table of sag values ​​of the lens surfaces of the first lens to the seventh lens in the optical system, Figure 29 It shows Figure 25 Table of the inclination angles of the lens surfaces of the first lens to the seventh lens in the optical system, Figure 30 It shows Figure 25 A graph showing the diffraction MTF data of an optical system at room temperature. Figure 31 It shows Figure 25 A graph showing data on aberration characteristics of an optical system at room temperature. Figure 32 It shows Figure 25 The graph of the diffraction MTF (Modulation Transfer Function) data of the optical system shown at low temperature is shown in FIG. Figure 33 It shows Figure 25 The graph of data on aberration characteristics of the optical system shown at low temperatures is shown in FIG. Figure 34 It shows Figure 25 The graph of the diffraction MTF data of the optical system at high temperature is shown in the figure. Figure 35 It shows Figure 25 A graph of aberration characteristic data of the optical system at high temperature, and Figure 36 It shows Figure 25 A graph of the peripheral light intensity ratio of the optical system.

[0369] Reference Figure 25 The optical system (1200) may include a lens unit, and the lens unit may include a first lens (301) to a seventh lens (307). The first lens to the seventh lens (301 to 307) may be sequentially arranged along an optical axis (OA) of the optical system (1200). Light corresponding to information of an object may pass through the first lens (301) to the seventh lens (307) and the filter (600) and enter the image sensor (500).

[0370] The first lens (301) may be arranged closest to the object side. The first lens (301) may be arranged farthest from the sensor side. The first lens (301) may have a negative (-) refractive power relative to the optical axis (OA). The first lens (301) may include a plastic material or a glass material and may be made of glass, for example. The first lens (301) made of glass can reduce changes in the center position and the curvature radius due to temperature changes caused by the surrounding environment, and can protect the incident side surface of the optical system (1200).

[0371] Based on the optical axis, the object-side first surface (S1) of the first lens (301) may be convex, and the sensor-side second surface (S2) may be concave. The first lens (301) may have a convex meniscus shape on the object side. The first lens (301) may have a concave meniscus shape on the sensor side. The first lens (301) may be made of a glass material and may have an aspherical surface. At least one or both of the first surface (S1) and the second surface (S2) may be aspherical. The aspheric coefficients of the first surface and the second surface (S1, S2) may be as follows Figure 26 At least one or both of the first surface (S1) and the second surface (S2) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0372] Due to the refractive properties of the first lens (301), the second lens (302) can be spaced further from the first lens (301). In other words, the center gap between the first lens (301) and the second lens (302) can be the largest in the lens unit.

[0373] The refractive index (n1) of the first lens (301) may satisfy the condition n1>1.6 or n1>1.62. When the refractive index (n1) of the first lens (301) satisfies the above condition, the curvature radius of the first lens and the second lens (301, 302) may be increased, thereby making lens manufacturing easier. If the refractive index (n1) of the first lens (301) is less than the condition, the refractive power of the first lens and the second lens (301, 302) must be increased by forming a sharply concave or convex lens surface. In this case, lens manufacturing becomes difficult and the lens defect rate may increase, resulting in a decrease in the yield rate.

[0374] The second lens (302) may be arranged second from the object side. The second lens (302) may be arranged sixth from the sensor side. The second lens (302) may be arranged between the first lens (301) and the third lens (303). The second lens (302) may have a negative (-) refractive power along the optical axis (OA). The second lens (302) may include a plastic or glass material. For example, the second lens (302) may be provided as a plastic material.

[0375] Based on the optical axis (OA), the object side third surface (S3) of the second lens (302) may be concave, and the sensor side fourth surface (S4) may be convex. The second lens (302) may have a convex meniscus shape toward the sensor side. The second lens (302) may have a concave meniscus shape on the object side. The second lens (302) may be made of a plastic material and may be aspherical. At least one or both of the third surface (S3) and the fourth surface (S4) may be aspherical. The aspheric coefficients of the third surface and the fourth surface (S3, S4) may be as follows Figure 26 At least one or both of the third surface (S3) and the fourth surface (S4) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0376] An aperture (stop) can be provided around the periphery of the sensor-side fourth surface (S4) of the second lens (302). An aperture (stop) can be provided around the periphery of the object-side fifth surface (S5) of the third lens (303). The aperture can reduce the TTL within the field of view and achieve miniaturization of the optical system. Therefore, it is possible to prevent a decrease in the weight-based yield (yield by weight) of the optical system and improve production efficiency. In addition, by reducing the TTL within the horizontal field of view (FOV_H) of 40 to 50 degrees, the optical system can be miniaturized.

[0377] The third lens (303) may be provided as the third lens on the object side. The third lens (303) may be provided as the fifth lens from the sensor side. The third lens (303) may be provided between the second lens (302) and the fourth lens (304). The third lens (303) may have a positive (+) refractive power along the optical axis (OA). The third lens (303) may include a plastic or glass material. For example, the third lens (303) may be provided as a glass material.

[0378] The object-side fifth surface (S5) of the third lens (303) may be convex, and the sensor-side sixth surface (S6) may be convex based on the optical axis. The third lens (303) may have a shape in which both surfaces are convex. The third lens (303) may be made of a glass material and may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be arranged so as not to have a critical point from the optical axis (OA) to the end of the effective area.

[0379] The fourth lens (304) may be arranged fourth from the object side. The fourth lens (304) may be arranged fourth from the sensor side. The fourth lens (304) may be arranged between the third lens (303) and the fifth lens (305). The fourth lens (304) may have positive (+) or negative (-) refractive power on the optical axis (OA). The fourth lens (304) may have positive (+) refractive power. The fourth lens (304) may include a plastic or glass material. For example, the fourth lens (304) may be provided as a plastic material.

[0380] Based on the optical axis, the object-side seventh surface (S7) of the fourth lens (304) may be convex, and the sensor-side eighth surface (S8) may be convex. The fourth lens (304) may have a shape in which both surfaces are convex. The fourth lens (304) may be made of a plastic material and may be aspherical. At least one or both of the seventh surface (S7) and the eighth surface (S8) may be aspherical. The aspherical coefficients of the seventh surface and the eighth surface (S7, S8) may be as follows: Figure 26 At least one or both of the seventh surface (S7) and the eighth surface (S8) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0381] The fifth lens (305) may be provided as the fifth lens from the object side. The fifth lens (305) may be provided as the third lens from the sensor side. The fifth lens (305) may be provided between the fourth lens (304) and the sixth lens (306). The fifth lens (305) may have positive (+) or negative (-) refractive power along the optical axis (OA). The fifth lens (305) may have negative (-) refractive power. The fifth lens (305) may include a plastic or glass material. For example, the fifth lens (305) may be provided as a plastic material.

[0382] The fifth lens (305) may have a ninth surface (S9) that is convex on the object side and a tenth surface (S10) that is concave on the sensor side relative to the optical axis (OA). The fifth lens (305) may have a convex meniscus shape on the object side. The fifth lens (305) may have a concave meniscus shape on the sensor side. The fifth lens (305) may be made of a plastic material and may be aspherical. At least one or both of the ninth surface (S9) and the tenth surface (S10) may be aspherical. The aspheric coefficients of the ninth surface and the tenth surface (S9, S10) may be as follows Figure 26 At least one or both of the ninth surface (S9) and the tenth surface (S10) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0383] The sixth lens (306) may be arranged to be the sixth from the object side. The sixth lens (306) may be arranged to be the second from the sensor side. The sixth lens (306) may be arranged between the fifth lens (305) and the seventh lens (307). The sixth lens (306) may have a positive (+) or negative (-) refractive power relative to the optical axis (OA). The sixth lens (306) may have a positive (+) refractive power. The sixth lens (306) may include a plastic or glass material. For example, the sixth lens (306) may be provided as a plastic material.

[0384] The sixth lens (306) may have an 11th surface (S11) that is convex on the object side and a 12th surface (S12) that is convex on the sensor side relative to the optical axis (OA). The sixth lens (306) may have a shape in which both surfaces are convex. The sixth lens (306) may be made of a plastic material and may be aspherical. At least one or both of the 11th surface (S11) and the 12th surface (S12) may be aspherical. The aspherical coefficients of the 11th surface and the 12th surface (S11, S12) may be as follows: Figure 26 Available in S1 and S2 of L6.

[0385] The 11th surface (S11) of the 6th lens (106) can be configured to have no critical point from the optical axis (OA) to the end of the effective area. The 12th surface (S12) of the 6th lens (106) can include a critical point from the optical axis (OA) to the end of the effective area. When the 12th surface (S12) has a critical point, the critical point can be located in the range of 75% to 80% of the effective radius (r62) from the optical axis (OA), preferably in the range of 76% to 77%. The critical point of the 12th surface (S12) can be located in the range of 3.3 mm to 4 mm from the optical axis (OA), preferably in the range of 3.5 mm to 3.6 mm.

[0386] The seventh lens (307) may be disposed farthest from the object side. The seventh lens (307) may be disposed closest to the image sensor (500). The seventh lens (307) may have positive (+) or negative (-) refractive power relative to the optical axis (OA). The seventh lens (307) may have negative (-) refractive power. The seventh lens (307) may include a plastic or glass material. For example, the seventh lens (307) may be provided as a plastic material.

[0387] The seventh lens (307) may have a convex 13th surface (S13) on the object side and a concave 14th surface (S14) on the sensor side relative to the optical axis (OA). The seventh lens (307) may have a convex meniscus shape on the object side. The seventh lens (307) may have a concave meniscus shape on the sensor side. At least one or both of the 13th surface (S13) and the 14th surface (S14) may be aspherical. The aspheric coefficients of the 13th surface and the 14th surface (S13, S14) may be as follows: Figure 26 Available in S13 and S14 of L7.

[0388] The 13th surface (S13) of the 7th lens (307) can be configured to have no critical point from the optical axis (OA) to the end of the effective area. The 14th surface (S14) of the 7th lens (307) can include a critical point from the optical axis (OA) to the end of the effective area. If the 14th surface (S14) has a critical point, the critical point can be located in the range of 65% to 75% of the effective radius (r72) from the optical axis (OA), preferably in the range of 69% to 72%. The critical point of the 14th surface (S14) can be located in the range of 3.5 mm to 4 mm from the optical axis (OA), preferably in the range of 3.7 mm to 3.8 mm.

[0389] The seventh lens (307) may be a plastic lens that is closest to the image sensor (500). In addition, by arranging two or more plastic lenses adjacent to the image sensor (500), it is possible to improve induced aberrations such as spherical aberration and chromatic aberration by having a lens surface with an aspherical shape, and to control resolution. In addition, by arranging the plastic lens as a lens adjacent to the image sensor (500), it is possible to be less sensitive to assembly tolerances than glass lenses. In other words, being less sensitive to assembly tolerances means that even if the assembly differs slightly from the design during assembly, the optical performance may not be significantly affected. In addition, by providing the two lenses (306, 307) adjacent to the image sensor (500) with plastic material, it is possible to improve optical performance by, for example, improving aberration characteristics and preventing resolution degradation by having aspherical lens surfaces.

[0390] [Table 7]

[0391]

[0392]

[0393] Table 7 shows the surface number (Surface), curvature radius (Radius), center thickness of each lens or distance between lens surfaces (Thickness), refractive index (Index, nd), Abbe number (Abbe, vd), effective radius (Semi Aperture), and focal length (Focal length) of the lenses according to the third embodiment of the present invention. Here, the unit of the curvature radius and thickness or distance can be mm.

[0394] [Table 8]

[0395]

[0396]

[0397] Table 8 shows the values ​​of each item in the above mathematical formula in the optical system (1200) of the third embodiment, which includes the total track length (TTL) (mm), back focal length (BFL), effective focal length (F) (mm), image height (ImgH) (mm), effective diameter (CA) (mm), thickness (mm), TTL (mm), optical axis distance TD from the first surface (S1) to the twelfth surface (S12) (mm), sum of refractive index, sum of Abbe number, sum of thickness (mm), sum of distances between adjacent lenses, effective diameter characteristics, sum of refractive index of glass lenses, sum of refractive index of plastic material, field of view (FOV_H) (degrees), edge thickness (ET), aperture number, etc.

[0398] The center thicknesses of the first to seventh lenses (301 to 307) are indicated as CT1 to CT7, the edge thicknesses at the ends of the effective areas of each lens are indicated as ET1 to ET7, the center gaps between adjacent lenses are indicated as CG1 to CG6, and the edge gaps between the edges of each lens are indicated as EG1 to EG6. The back focus (BFL) is the optical axis distance from the image sensor (500) to the center of the last lens. The TTL is the optical axis distance from the center of the first surface (S1) of the first lens (301) to the image surface of the image sensor (500).

[0399] like Figure 26As shown, the lens surfaces of the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens (301, 302, 304, 305, 306, 307) in the lens unit of the third embodiment may include aspheric surfaces having a 30th-order aspheric coefficient. For example, the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens (301, 302, 304, 305, 306, 307) may include lens surfaces having a 30th-order aspheric coefficient. As described above, the aspheric surface having a 30th-order aspheric coefficient (a non-zero value) can significantly change the aspheric shape in the peripheral region, thereby effectively correcting the optical performance in the peripheral region of the field of view (FOV).

[0400] The thicknesses (T1 to T7) of the first to seventh lenses (301 to 307) and the gaps (G1 to G6) between adjacent lenses may be set. Figure 3 As shown, the thickness of each lens in the Y-axis direction (T1 to T7) can be displayed at intervals of 0.1 mm or 0.2 mm or more, and the gap between each lens (G1 to G6) can be displayed at intervals of 0.1 mm or 0.2 mm or more.

[0401] When comparing the absolute values ​​of the curvature radii of each lens, the curvature radius of the first surface (S1) of the first lens (301) on the optical axis (OA) may be the largest among the lenses, and the curvature radius of the tenth surface (S10) of the fifth lens (305) may be the smallest among the lenses. The difference between the maximum curvature radius and the minimum curvature radius may be three times or more, for example, in the range of three times to five times.

[0402] Among the object-side and sensor-side surfaces of the first to seventh lenses (301 to 307), the number of lens surfaces having a radius of curvature greater than 40° may be one or more but not more than four. This allows the radius of curvature of the lenses constituting the optical system (1200) to be designed to have mostly small values, thereby satisfying the field of view, focal length, and total length of the lenses when they are installed in a vehicle.

[0403] 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 stronger refractive power to refract light through the plastic lens. In addition, in order to increase the refractive power, the curvature radius of the lens surface can be smaller.

[0404] The absolute value of the radius of curvature of the first surface (S1) of the first lens (301) may be greater than the absolute value of the radius of curvature of the second surface (S2). The absolute value of the radius of curvature of the third surface (S3) of the second lens (302) may be smaller than the absolute value of the radius of curvature of the fourth surface (S4). The absolute value of the radius of curvature of the fifth surface (S5) of the third lens (303) may be greater than the absolute value of the radius of curvature of the sixth surface (S6). The absolute value of the radius of curvature of the seventh surface (S7) of the fourth lens (304) may be smaller than the absolute value of the radius of curvature of the eighth surface (S8). The absolute value of the radius of curvature of the ninth surface (S9) of the fifth lens (305) may be greater than the absolute value of the radius of curvature of the tenth surface (S10). The absolute value of the radius of curvature of the eleventh surface (S11) of the sixth lens (306) may be greater than the absolute value of the radius of curvature of the twelfth surface (S12). The absolute value of the radius of curvature of the 13th surface (S13) of the 7th lens (307) may be greater than the absolute value of the radius of curvature of the 14th surface (S14).

[0405] The ratio of the curvature radius of each lens may satisfy the following conditions.

[0406] Condition 1: 1<|L1R1 / L1R|<1.5

[0407] Condition 2: 0.5<|L2R1 / L2R2|<1

[0408] Condition 3: 1.8 < |L3R1 / L3R2| < 2.2

[0409] Condition 4: 0.1<|L4R1 / L4R2|<0.5

[0410] Condition 5: 40<|L5R1 / L5R2|<50

[0411] Condition 6: 5<|L6R1 / L6R2|<10

[0412] Condition 7: 2<|L7R1 / L7R2|<8

[0413] When describing the center thickness (CT) of the lens based on the optical axis, the center thickness (CT4) of the fourth lens (304) may be the largest among the lenses, and at least one of the center thicknesses (CT1, CT5, CT7) of the first lens (301), the fifth lens (305), and the seventh lens (307) may be the smallest among the lenses. The difference between the maximum center thickness and the minimum center thickness of the lens may be within a range of 2 mm or more and 2.5 mm or less.

[0414] The center thickness of each lens may satisfy any one of the following conditions.

[0415] Condition 1: CT2, CT3, CT4, CT6 > CT1 = CT5 = CT7

[0416] Condition 2: CT3, CT4 > CT2 > CT1, CT5, CT6, CT7

[0417] Condition 3: CT4 > CT3 > CT1, CT2, CT5, CT6, CT7

[0418] Condition 4: CT4 > CT1, CT2, CT3, CT6, CT7

[0419] Condition 5: CT2, CT3, CT4 > CT6 > CT1, CT5, CT7

[0420] The center gaps (CG) between the lenses are described as follows: the center gap (CG1) between the first lens (301) and the second lens (302) may be the largest, and the center gap (CG6) between the sixth lens (306) and the seventh lens (307) may be the smallest. The difference between the largest center gap and the smallest center gap among the spaced lenses may be 3 mm or more, for example, in the range of 3 mm to 4 mm.

[0421] The center gap between each lens can satisfy the following conditions.

[0422] Condition 1: CG1 > CG2, CG3, CG4, CG5, CG6

[0423] Condition 2: CG1, CG5 > CG2 > CG3, CG4, CG6

[0424] Condition 3: CG1, CG2, CG5 > CG3 > CG4, CG6

[0425] Condition 4: CG1, CG2, CG3, CG5 > CG4 > CG6

[0426] Condition 5: CG1 > CG5 > CG2, CG3, CG4, CG6

[0427] ※Condition 6: CG1, CG2, CG3, CG4, CG5 > CG6

[0428] Regarding the effective diameter, the lens with the largest effective diameter may be a lens made of a glass material. The lens with the largest effective diameter may be the fourth lens (304). Here, the effective diameter is the average of the effective diameter on the object side and the effective diameter on the sensor side of each lens. The lens surface with the largest effective diameter may be the seventh surface (S7) of the fourth lens (304). The lens with the smallest effective diameter may be the second lens (302). The lens surface with the smallest effective diameter may be the fourth surface (S4) of the second lens (302). The effective diameter of the plastic lens may be smaller than the effective diameter of the glass lens. The plastic lens may be disposed adjacent to the image sensor.

[0429] The effective diameter of each lens may satisfy any one of the following conditions.

[0430] Condition 1: CA_L4, CA_L5, CA_L7>CA_L1>CA_L2, CA_L3, CA_L6

[0431] Condition 2: CA_L1, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7>CA_L2

[0432] Condition 3: CA_L1, CA_L4, CA_L5, CA_L7>CA_L3>CA_L2, CA_L6

[0433] Condition 4: CA_L4>CA_L1, CA_L2, CA_L3, CA_L5, CA_L6, CA_L7

[0434] Condition 5: CA_L4, CA_L7>CA_L5>CA_L1, CA_L2, CA_L3, CA_L6

[0435] Condition 6: CA_L1, CA_L3, CA_L4, CA_L5, CA_L7>CA_L6>CA_L2

[0436] Condition 7: CA_L4>CA_L7>CA_L1, CA_L2, CA_L3, CA_L5, CA_L6

[0437] Regarding the refractive index, the refractive index of the fifth lens (305) can be the highest among the lenses, exceeding 1.6, for example, exceeding 1.65. The second lens (302), the fourth lens (304), the sixth lens (306), and the seventh lens (307) can individually or collectively have the lowest refractive index among the lenses. For example, the refractive index of the second lens (302), the sixth lens (306), and the seventh lens (108) can be the lowest among the lenses, less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index can be 0.2 or greater. By providing a lens closest to the object made of a glass material with the highest refractive index, and providing a lens adjacent to the glass material lens and a lens adjacent to the image sensor (500) with a lens made of a plastic material with the lowest refractive index, the incident efficiency can be increased, and the refractive power between the lenses made of the glass material and the plastic material can be controlled to guide light to the image sensor (500).

[0438] The refractive index of each lens may satisfy any one of the following conditions.

[0439] Condition 1: n5 > n1 > n2, n3, n4, n6, n7

[0440] Condition 2: n1, n3, n5 > n2 = n4 = n6 = n7

[0441] Condition 3: n1, n5 > n3 > n2, n4, n6, n7

[0442] Condition 4: n5 > n1, n2, n3, n4, n6, n7

[0443] When comparing Abbe numbers, the Abbe number of the third lens (303) may be the largest among the lenses and may be 60 or higher. The Abbe number of the fifth lens (305) may be the smallest among the lenses and may be 25 or lower. The difference between the maximum refractive index and the minimum Abbe number may be 40 or higher. By maximizing the Abbe number of the third lens (303) disposed at the center of the optical system (1200) and minimizing the Abbe number of the fifth lens (305) having a low refractive index adjacent to the image sensor (500), dispersion of light passing through lenses made of a glass material and a plastic material may be controlled, and dispersion between lenses made of a glass material and a plastic material may be increased, so that light can be guided to the image sensor (500).

[0444] The Abbe number of each lens may satisfy any one of the following conditions.

[0445] Condition 1: v2, v3, v4, v6, v7 > v1 > v5

[0446] Condition 2: v3 > v2 = v4 = v6 = v7 > v1, v5

[0447] Condition 3: v3 > v1, v2, v4, v5, v6, v7

[0448] Condition 4: v1, v2, v3, v4, v6, v7 > v5

[0449] The focal lengths (F1, F2, F5, F7) of the first lens, the second lens, the fifth lens, and the seventh lens (301, 302, 305, 307) may have a negative (-) sign. The first lens, the second lens, the fifth lens, and the seventh lens (301, 302, 305, 307) may have a negative (-) refractive power. The focal lengths (F3, F4, F6) of the third lens, the fourth lens, and the sixth lens (303, 304, 306) may have a positive (+) sign. The third lens, the fourth lens, and the sixth lens (303, 304, 306) may have a positive (+) refractive power. The sensor side of the first lens (301) and the second lens (302) having negative (-) refractive power may be provided with a third lens (303) having positive (+) refractive power. Thus, light incident from the object side can move away from the optical axis direction and then converge again toward the optical axis direction, thereby forming a stable optical path.

[0450] In addition, the fourth lens (304) and the fifth lens (305) as adjacent lenses can satisfy the following conditions.

[0451] Condition 1: The refractive index of the lens with positive refractive power is less than the refractive index of the lens with negative refractive power.

[0452] Condition 2: The dispersion value of the lens with positive refractive power > the dispersion value of the lens with negative refractive power

[0453] Here, among the plastic lenses, the fourth lens (304) has positive refractive power, and the fifth lens (305) has negative refractive power. According to conditions 1 and 2, the refractive index of the fourth lens (304) can be smaller than the refractive index of the fifth lens (305), and the dispersion value of the fourth lens (304) can be larger than the dispersion value of the fifth lens (305). Chromatic aberration occurring in the plastic lens can be corrected using the plastic lens. In addition, when the fourth lens (304) and the fifth lens (305) as continuously arranged plastic lenses satisfy the conditions of a refractive index difference of 0.1 or more and 0.15 or less and an Abbe number difference of 20 or more and 50 or less, chromatic aberration occurring in the plastic lens can be compensated using the plastic lens.

[0454] The optical system exhibits chromatic aberration, which is corrected using two lenses arranged in series or a cemented lens. As the temperature changes from low to high, the lenses repeatedly shrink and expand. Since lenses made of the same material exhibit the same change in lens characteristics due to temperature changes, it is effective to correct chromatic aberration between lenses made of the same material even when the temperature changes. Therefore, in the third embodiment of the present invention, the fourth lens (304) and the fifth lens (305) can be used to correct chromatic aberration occurring in the plastic lens.

[0455] From the optical axis to the effective diameter area, the maximum distance between the two lenses with the largest Abbe number difference among the two adjacent lenses can be smaller than the maximum distance between other adjacent lens pairs. Here, the distance can refer to the distance from the optical axis to the effective diameter area between the two lenses. The two lenses with the largest Abbe number difference among the two adjacent lenses can be the fourth lens (304) and the fifth lens (305). Between the 8th surface (S8) of the sensor side surface of the fourth lens (304) and the 9th surface (S9) of the object side surface of the fifth lens (305), the maximum distance value from the optical axis to the effective diameter area in the direction perpendicular to the optical axis can be smaller than the maximum distance value between any two adjacent lenses. This makes the distance between the two lenses made of plastic materials that are difficult to join smaller, maximizes the Abbe number difference, and achieves the same chromatic aberration reduction as the joined lenses even when not joined.

[0456] When the focal lengths are compared as absolute values, the focal length of the first lens (301) may be the largest among the lenses and may be between 70 and 80. The focal length of the sixth lens (306) may be the smallest among the lenses, and the absolute value of the focal length of the sixth lens (306) may be between 8 and 12.

[0457] Since the first lens (301) has the largest focal length and the weakest refractive power among the lenses, the difference in Abbe number between the second lens (302) and the third lens (303) arranged on the sensor side of the first lens (301) does not need to be very large to achieve the effect of correcting chromatic aberration.

[0458] The absolute value of the focal length of each lens may satisfy any one of the following conditions.

[0459] Condition 1: |f1|>|f2|, |f3|, |f4|, |f5|, |f6|, |f7|

[0460] Condition 2: |f1|>|f2|>|f3|, |f4|, |f5|, |f6|, |f7|

[0461] Condition 3: |f1|, |f2|, |f4|>|f3|>|f5|, |f6|, |f7|

[0462] Condition 4: |f1|, |f2|>|f4|>|f3|, |f5|, |f6|, |f7|

[0463] Condition 5: |f1|, |f2|, |f3|, |f4|, |f7|>|f5|>|f6|

[0464] Condition 6: |f1|, |f2|, |f3|, |f4|, |f5|, |f7|>|f6|

[0465] Condition 7: |f1|, |f2|, |f3|, |f4|>|f7|>|f5|, |f6|

[0466] The thickness (T1) of the first lens (301) may be in the range of 1.5 times to 2 times, for example, the difference between the maximum thickness and the minimum thickness may be 1.5 times or more, and the center thickness (CT1) may be the smallest and the edge thickness (ET1) may be the largest. The maximum thickness (T2) of the second lens (302) may be in the range of 1 times to 1.5 times the minimum thickness. The second lens (302) may have a minimum thickness (CT2) at the center and a maximum thickness (ET2) at the edge. The thickness (T3) of the third lens (303) may be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 1 to 1.5 times the minimum thickness. The thickness (T4) of the fourth lens (304) may be the largest at the center and the smallest at the edge, wherein the maximum thickness is in the range of 2 to 2.5 times the minimum thickness. The thickness (T5) of the fifth lens (305) may be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 1.2 to 1.7 times the minimum thickness. The thickness (T6) of the sixth lens (306) may be maximum at the center and minimum at the edge, wherein the maximum thickness is in the range of 1.2 to 1.7 times the minimum thickness. The thickness (T7) of the seventh lens (307) may be minimum at the center and maximum at the edge, wherein the maximum thickness is in the range of 1 to 1.5 times the minimum thickness.

[0467] The thickness of each lens may satisfy any one of the following conditions.

[0468] Condition 1: 0.5<CT1 / ET1<1, 1.5<ET1 / CT1<2

[0469] Condition 2: 0.5<CT2 / ET2<1, 1<ET2 / CT2<1.5

[0470] Condition 3: 0.5<CT3 / ET3<1, 1<ET3 / CT3<1.5

[0471] Condition 4: 2<CT4 / ET4<2.5, 0.1<ET4 / CT4<0.5

[0472] Condition 5: 0.5<CT5 / ET5<1, 1.2<ET5 / CT5<1.7

[0473] Condition 6: 1.2<CT6 / ET6<1.7, 0.5<ET6 / CT6<1

[0474] Condition 7: 0.5<CT7 / ET7<1, 1<ET7 / CT7<1.5

[0475] Condition 8: 1<ΣCT / ΣET<1.2, 0.5<ΣET / ΣCT<1

[0476] Among the gaps (G1 to G7) between the lenses, the first gap (G1) between the first lens (301) and the second lens (302) may have a maximum value at the center and a minimum value at the edge. The second gap (G2) between the second lens (302) and the third lens (303) may have a minimum value at the center and a maximum value at the edge. The third gap (G3) between the third lens (303) and the fourth lens (304) may have a maximum value at the edge and a minimum value at the center. The fourth gap (G4) between the fourth lens (304) and the fifth lens (305) may have a minimum value at the center and a maximum value at the edge. The fifth gap (G5) between the fifth lens (305) and the sixth lens (306) may have a maximum value at the center portion and a minimum value at the edge portion. The sixth gap (G6) between the sixth lens (306) and the seventh lens (307) may have a minimum value at the center portion and a maximum value at the edge portion.

[0477] Figure 30 、 Figure 32 and Figure 34 are shown separately Figure 25 The graphs show the diffraction MTF (Modulation Transfer Function) of the optical system at room temperature, low temperature and high temperature. These graphs show the modulation (brightness ratio) as a function of spatial frequency. Figure 30 、 Figure 32 and Figure 34 As shown, in the third embodiment of the present invention, the deviation of the MTF between room temperature and low temperature or high temperature can be less than 10%, that is, 7% or less.

[0478] Figure 31 、 Figure 33 and Figure 35 It shows Figure 25 Graphs showing aberration characteristics of an optical system at room temperature, low temperature, and high temperature. Figure 31 、 Figure 33 and Figure 35 The aberration curve diagram in FIG shows the measured values ​​of spherical aberration (longitudinal spherical aberration), astigmatism field curve (Astigmatic Field Curve) and distortion (Distortion) from left to right. Figure 31 、 Figure 33 and Figure 35 In FIG, the X-axis may represent focal length (mm) and distortion (%), and the Y-axis may represent image height (height). In addition, the graph for spherical aberration corresponds to light in the wavelength bands of approximately 435 nm, 486 nm, 546 nm, 587 nm, and 656 nm, and the graph for astigmatism field curve and distortion corresponds to light in the wavelength band of approximately 546 nm. Figure 31 、 Figure 33 and Figure 35 In the aberration diagram of , the closer the curves at room temperature, low temperature, and high temperature are to the Y-axis, the better the aberration correction function is explained. The optical system (1200) according to the third embodiment shows that the measured values ​​are adjacent to the Y-axis in almost all areas. In other words, the optical system (1000) according to the third embodiment has improved resolution and can achieve good optical performance not only in the central part of the field of view (FOV) but also in the peripheral part. Here, low temperature may refer to a temperature of -20°C or lower, for example, -20°C to -40°C, room temperature may refer to a range of 22°C±5°C or 18°C ​​to 27°C, and high temperature may refer to a temperature of 85°C or higher, for example, 85°C to 105°C. Therefore, as Figure 31 、 Figure 33 and Figure 35 As shown, it can be seen that the brightness modulation from low temperature to high temperature decreases by less than 10%, such as 5% or less, or remains almost unchanged.

[0479] Table 9 compares 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 third embodiment. It can be seen that the rate of change in optical characteristics at low temperature is 5% or less, for example, 3% or less, compared to room temperature. It can be seen that the rate of change in optical characteristics at low temperature is 5% or less, for example, 3% or less, compared to room temperature.

[0480] [Table 9]

[0481] Room temperature Low temperature high temperature Low temperature / room temperature High temperature / room temperature EFL(F) 10.88 10.79 11.00 99.17％ 101.10％ BFL 3.49 3.49 3.50 100.00％ 100.28％ F# 1.64 1.63 1.66 99.39％ 101.21％ TTL 30.00 29.93 30.09 99.76％ 100.30％ FOV_D 54.34 54.81 53.79 100.86％ 98.98％

[0482] Therefore, as shown in Table 9, the change in optical characteristics due to temperature change from low temperature to high temperature (e.g., the rate of change of effective focal length (EFL), TTL, BFL, f-number, and field of view (FOV_D)) is 10% or less, that is, 5% or less, for example, within the range of 0 to 5%. This design allows temperature compensation of the plastic lens even when using one or more plastic lenses, thereby preventing a decrease in the reliability of the optical characteristics.

[0483] The optical system disclosed in the third embodiment can effectively control aberration characteristics such as chromatic aberration and distortion, and provide good optical performance not only in the central portion of the field of view (FOV) but also in the peripheral portion.

[0484] An optical system according to a fourth embodiment of the present invention will now be described.

[0485] Figure 37 is a side sectional view of an optical system and an image pickup device module including the optical system according to a fourth embodiment, Figure 38 It shows Figure 37 Table of aspheric coefficients of lenses in optical systems, Figure 39 It shows Figure 37 A table showing the thickness of each lens in the optical system and the gaps between adjacent lenses. Figure 40 It shows Figure 37 Table of sag values ​​of the lens surfaces of the first lens to the seventh lens in the optical system, Figure 41 It shows Figure 37 Table of the inclination angles of the lens surfaces of the first lens to the seventh lens in the optical system, Figure 42 It shows Figure 37 The graph of the diffraction MTF (Modulation Transfer Function) data of the optical system shown at room temperature is shown in FIG. Figure 43 It shows Figure 37 The graph of the aberration characteristics of the optical system shown at room temperature is shown in FIG. Figure 44 It shows Figure 37 The graph of the diffraction MTF data of the optical system shown at low temperature is Figure 45 It shows Figure 37 The graph of data on aberration characteristics of the optical system shown at low temperatures is shown in FIG. Figure 46 It shows Figure 37 The graph of the diffraction MTF data of the optical system shown at high temperature is shown in FIG. Figure 47 It shows Figure 37 A graph showing data on aberration characteristics of the optical system at high temperatures, and Figure 48 It shows Figure 37 A graph showing the peripheral light intensity ratio of the optical system shown.

[0486] Reference Figure 37 The optical system (1300) may include a lens unit, and the lens unit may include a first lens (401) to a seventh lens (407). The first lens to the seventh lens (401 to 407) may be sequentially arranged along an optical axis (OA) of the optical system (1300). Light corresponding to information of an object may pass through the first lens (401) to the seventh lens (407) and the filter (600) and enter the image sensor (500).

[0487] The first lens (401) may be arranged closest to the object side. The first lens (401) may be arranged farthest from the sensor side. The first lens (401) may have a negative (-) refractive power relative to the optical axis (OA). The first lens (401) may include a plastic material or a glass material and may be made of glass, for example. The first lens (401) made of glass can reduce changes in the center position and the curvature radius caused by temperature changes caused by the surrounding environment and can protect the incident side of the optical system (1300).

[0488] Based on the optical axis, the object side first surface (S1) of the first lens (401) may be convex, and the sensor side second surface (S2) may be concave. The first lens (401) may have a convex meniscus shape on the object side. The first lens (401) may have a concave meniscus shape on the sensor side. The first lens (401) may be made of a glass material and may have an aspherical surface. At least one or both of the first surface (S1) and the second surface (S2) may be aspherical. The aspheric coefficients of the first surface and the second surface (S1, S2) may be as follows Figure 38 At least one or both of the first surface (S1) and the second surface (S2) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0489] Due to the refractive properties of the first lens (401), the second lens (402) can be spaced further apart from the first lens (401). In other words, the center gap between the first lens (401) and the second lens (402) can be the largest within the lens unit.

[0490] The refractive index (n1) of the first lens (401) may satisfy the condition n1>1.6 or n1>1.62. When the refractive index (n1) of the first lens (401) satisfies the above condition, the curvature radius of the first lens and the second lens (401, 402) can be increased, thereby making lens manufacturing easier. If the refractive index (n1) of the first lens (401) is less than the condition, the refractive power of the first lens and the second lens (401, 402) must be increased by forming a sharply concave or convex lens surface, which makes lens manufacturing difficult, increases the defect rate, and may lead to a decrease in the yield rate.

[0491] The second lens (402) may be arranged second from the object side. The second lens (402) may be arranged sixth from the sensor side. The second lens (402) may be arranged between the first lens (401) and the third lens (403). The second lens (402) may have a negative (-) refractive power along the optical axis (OA). The second lens (402) may include a plastic or glass material. For example, the second lens (402) may be provided as a plastic material.

[0492] Based on the optical axis (OA), the object side third surface (S3) of the second lens (402) may be concave, and the sensor side fourth surface (S4) may be convex. The second lens (402) may have a convex meniscus shape toward the sensor side. The second lens (402) may have a concave meniscus shape on the object side. The second lens (402) may be made of a plastic material and may be aspherical. At least one or both of the third surface (S3) and the fourth surface (S4) may be aspherical. The aspheric coefficients of the third surface and the fourth surface (S3, S4) may be as follows Figure 38 At least one or both of the third surface (S3) and the fourth surface (S4) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0493] An aperture (stop) can be provided around the periphery of the sensor-side fourth surface (S4) of the second lens (402). An aperture (stop) can be provided around the periphery of the object-side fifth surface (S5) of the third lens (403). The aperture can reduce the TTL within the field of view and achieve miniaturization of the optical system. Therefore, it is possible to prevent a decrease in the weight-based yield (yield by weight) of the optical system and improve production efficiency. In addition, by reducing the TTL within the horizontal field of view (FOV_H) of 40 to 50 degrees, the optical system can be miniaturized.

[0494] The third lens (403) may be provided as the third lens on the object side. The third lens (403) may be provided as the fifth lens from the sensor side. The third lens (403) may be provided between the second lens (402) and the fourth lens (404). The third lens (403) may have positive (+) refractive power along the optical axis (OA). The third lens (403) may include a plastic or glass material. For example, the third lens (403) may be provided as a glass material.

[0495] The object-side fifth surface (S5) of the third lens (403) may be convex, and the sensor-side sixth surface (S6) may be convex based on the optical axis. The third lens (403) may have a shape in which both surfaces are convex. The third lens (403) may be made of a glass material and may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be arranged so as not to have a critical point from the optical axis (OA) to the end of the effective area.

[0496] The fourth lens (404) may be arranged fourth from the object side. The fourth lens (404) may be arranged fourth from the sensor side. The fourth lens (404) may be arranged between the third lens (403) and the fifth lens (405). The fourth lens (404) may have positive (+) or negative (-) refractive power on the optical axis (OA). The fourth lens (404) may have positive (+) refractive power. The fourth lens (404) may include a plastic or glass material. For example, the fourth lens (404) may be provided as a plastic material.

[0497] Based on the optical axis, the object-side seventh surface (S7) of the fourth lens (404) may be convex, and the sensor-side eighth surface (S8) may be convex. The fourth lens (404) may have a shape in which both surfaces are convex. The fourth lens (404) may be made of a plastic material and may be aspherical. At least one or both of the seventh surface (S7) and the eighth surface (S8) may be aspherical. The aspherical coefficients of the seventh surface and the eighth surface (S7, S8) may be provided as Figure 38 At least one or both of the seventh surface (S7) and the eighth surface (S8) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0498] The fifth lens (405) may be arranged as the fifth lens from the object side. The fifth lens (405) may be arranged as the third lens from the sensor side. The fifth lens (405) may be arranged between the fourth lens (404) and the sixth lens (406). The fifth lens (405) may have positive (+) or negative (-) refractive power relative to the optical axis (OA). The fifth lens (405) may have negative (-) refractive power. The fifth lens (405) may include a plastic or glass material. For example, the fifth lens (405) may be provided in a plastic material.

[0499] The fifth lens (405) may have a ninth surface (S9) that is convex on the object side and a tenth surface (S10) that is concave on the sensor side relative to the optical axis (OA). The fifth lens (405) may have a convex meniscus shape on the object side. The fifth lens (405) may have a concave meniscus shape on the sensor side. The fifth lens (405) may be made of a plastic material and may be aspherical. At least one or both of the ninth surface (S9) and the tenth surface (S10) may be aspherical. The aspheric coefficients of the ninth surface and the tenth surface (S9, S10) may be provided as Figure 38 At least one or both of the ninth surface (S9) and the tenth surface (S10) may be configured to have no critical point from the optical axis (OA) to the end of the effective area.

[0500] The sixth lens (406) may be arranged as the sixth lens from the object side. The sixth lens (406) may be arranged as the second lens from the sensor side. The sixth lens (406) may be arranged between the fifth lens (405) and the seventh lens (407). The sixth lens (406) may have positive (+) or negative (-) refractive power relative to the optical axis (OA). The sixth lens (406) may have positive (+) refractive power. The sixth lens (406) may include a plastic or glass material. For example, the sixth lens (406) may be provided in a plastic material.

[0501] The sixth lens (406) may have an 11th surface (S11) that is convex on the object side and a 12th surface (S12) that is convex on the sensor side relative to the optical axis (OA). The sixth lens (406) may have a shape in which both surfaces are convex. The sixth lens (406) may be made of a plastic material and may be aspherical. At least one or both of the 11th surface (S11) and the 12th surface (S12) may be aspherical. The aspherical coefficients of the 11th surface and the 12th surface (S11, S12) may be provided as Figure 38 S1 and S2 of L6.

[0502] The 11th surface (S11) of the sixth lens (406) can be configured to have no critical point from the optical axis (OA) to the end of the effective area. The 12th surface (S12) of the sixth lens (406) can include a critical point from the optical axis (OA) to the end of the effective area. When the 12th surface (S12) has a critical point, it can be located in the range of 65% to 75% of the effective radius (r62) from the optical axis (OA), preferably in the range of 70% to 73%. The critical point of the 12th surface (S12) can be located in the range of 3 mm to 3.5 mm from the optical axis (OA), preferably in the range of 3.3 mm to 3.4 mm.

[0503] The seventh lens (407) may be disposed farthest from the object side. The seventh lens (407) may be disposed closest to the image sensor (500). The seventh lens (407) may have positive (+) or negative (-) refractive power relative to the optical axis (OA). The seventh lens (407) may have negative (-) refractive power. The seventh lens (407) may include a plastic or glass material. For example, the seventh lens (407) may be provided as a plastic material.

[0504] The seventh lens (407) may have a convex shape on the object side 13th surface (S13) and a concave shape on the sensor side 14th surface (S14) relative to the optical axis (OA). The seventh lens (407) may have a convex meniscus shape on the object side. The seventh lens (407) may have a concave meniscus shape on the sensor side. At least one or both of the 13th surface (S13) and the 14th surface (S14) may be aspherical. The aspheric coefficients of the 13th surface and the 14th surface (S13, S14) may be provided as Figure 38 S13 and S14 of L7 in.

[0505] The 13th surface (S13) of the 7th lens (407) can be set to have no critical point from the optical axis (OA) to the end of the effective area. The 14th surface (S14) of the 7th lens (407) can include a critical point from the optical axis (OA) to the end of the effective area. If the 14th surface (S14) has a critical point, it can be set in the range of 60% to 70% of the effective radius (r72) from the optical axis (OA), preferably in the range of 63% to 66%. The critical point of the 14th surface (S14) can be set in the range of 3mm to 3.5mm from the optical axis (OA), preferably in the range of 3.3mm to 3.4mm.

[0506] The seventh lens (407) may be a plastic lens that is closest to the image sensor (500). In addition, by arranging two or more plastic lenses adjacent to the image sensor (500), aberrations such as spherical aberration and chromatic aberration can be improved by having a lens surface with an aspherical shape, and resolution can be controlled. Furthermore, by arranging the plastic lens adjacent to the image sensor (500), it is possible to be less sensitive to assembly tolerances compared to glass lenses. In other words, being less sensitive to assembly tolerances means that even if the assembly differs slightly from the design during assembly, the optical performance may not be significantly affected. Furthermore, by providing the two lenses (406, 407) with a plastic material adjacent to the image sensor (500), it is possible to improve optical performance, such as improving aberration characteristics and preventing resolution degradation, by using aspherical lens surfaces.

[0507] [Table 10]

[0508]

[0509]

[0510] Table 10 shows the surface number (Surface), curvature radius (Radius), center thickness of each lens or distance between lens surfaces (Thickness), refractive index (Index, nd), Abbe number (Abbe, vd), effective radius (Semi Aperture), and focal length (Focallength) of the lenses according to the fourth embodiment of the present invention. Here, the units of the curvature radius and thickness or distance can be mm.

[0511] [Table 11]

[0512]

[0513]

[0514] Table 11 shows the values ​​of each term in the above mathematical formula for the optical system (1300) of the embodiment. The optical system (1300) may include a total track length (TTL) (mm), a back focal length (BFL), an effective focal length (F) (mm), an image height (ImgH) (mm), an effective aperture (CA) (mm), a thickness (mm), a TTL (mm), an optical axis distance TD from the first surface (S1) to the sixteenth surface (S16) (mm), a sum of refractive indices, a sum of Abbe numbers, a sum of thicknesses (mm), a sum of intervals between adjacent lenses, effective aperture characteristics, a sum of refractive indices of glass lenses, a sum of refractive indices of plastic materials, a field of view (FOV_H) (degrees), an edge thickness (ET), an F-number, and the like.

[0515] The center thicknesses of the first to seventh lenses (401 to 407) are indicated as CT1 to CT7, the edge thicknesses at the ends of the effective areas of each lens are indicated as ET1 to ET7, the center gaps between adjacent lenses are indicated as CG1 to CG6, and the edge gaps between the edges of each lens are indicated as EG1 to EG6. The back focus (BFL) is the optical axis distance from the image sensor (500) to the center of the last lens. The TTL is the optical axis distance from the center of the first surface (S1) of the first lens (401) to the image surface of the image sensor (500).

[0516] like Figure 38 As shown, the lens surfaces of the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens (401, 402, 404, 405, 406, 407) in the lens unit of the fourth embodiment may include aspheric surfaces having a 30th-order aspheric coefficient. For example, the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens (401, 402, 404, 405, 406, 407) may include lens surfaces having a 30th-order aspheric coefficient. As described above, the aspheric surface having a 30th-order aspheric coefficient (a non-zero value) can significantly change the aspheric shape in the peripheral region, thereby effectively correcting the optical performance in the peripheral region of the field of view (FOV).

[0517] The thicknesses (T1 to T7) of the first to seventh lenses (401 to 407) and the gaps (G1 to G6) between adjacent lenses may be set. Figure 3 As shown, the thickness of each lens in the Y-axis direction (T1 to T7) can be expressed at intervals of 0.1 mm or 0.2 mm or greater, and the gap between each lens (G1 to G6) can be expressed at intervals of 0.1 mm or 0.2 mm or greater.

[0518] When comparing the absolute values ​​of the radii of curvature of each lens, the radius of curvature of the ninth surface (S9) of the fifth lens (405) on the optical axis (OA) may be the largest among the lenses, and the radius of curvature of the third surface (S3) of the second lens (402) may be the smallest among the lenses. The difference between the maximum radius of curvature and the minimum radius of curvature may be 15 times or more, for example, in the range of 15 times to 25 times.

[0519] Among the object-side and sensor-side surfaces of the first to seventh lenses (401 to 407), the number of lens surfaces having a radius of curvature greater than 40° may be one or more but not more than four. This allows the radius of curvature of the lenses constituting the optical system (1300) to be designed to be mostly small, thereby satisfying the field of view, focal length, and total length of the lenses when they are installed in a vehicle.

[0520] Since the effective diameter of the plastic lens is smaller than that of the glass lens, the lens on the object side of the plastic lens can have a stronger refractive power to refract light through the plastic lens. In addition, in order to increase the refractive power, the curvature radius of the lens surface can be smaller.

[0521] The absolute value of the radius of curvature of the first surface (S1) of the first lens (401) may be greater than the absolute value of the radius of curvature of the second surface (S2). The absolute value of the radius of curvature of the third surface (S3) of the second lens (402) may be smaller than the absolute value of the radius of curvature of the fourth surface (S4). The absolute value of the radius of curvature of the fifth surface (S5) of the third lens (403) may be greater than the absolute value of the radius of curvature of the sixth surface (S6). The absolute value of the radius of curvature of the seventh surface (S7) of the fourth lens (404) may be smaller than the absolute value of the radius of curvature of the eighth surface (S8). The absolute value of the radius of curvature of the ninth surface (S9) of the fifth lens (405) may be greater than the absolute value of the radius of curvature of the tenth surface (S10). The absolute value of the radius of curvature of the eleventh surface (S11) of the sixth lens (406) may be greater than the absolute value of the radius of curvature of the twelfth surface (S12). The absolute value of the radius of curvature of the 13th surface (S13) of the 7th lens (407) may be greater than the absolute value of the radius of curvature of the 14th surface (S14).

[0522] The ratio of the curvature radius of each lens may satisfy the following conditions.

[0523] Condition 1: 1<|L1R1 / L1R|<1.5

[0524] Condition 2: 0.5<|L2R1 / L2R2|<1

[0525] Condition 3: 2.5<|L3R1 / L3R2|<3.5

[0526] Condition 4: 0.1<|L4R1 / L4R2|<0.5

[0527] Condition 5: 10<|L5R1 / L5R2|<20

[0528] Condition 6: 5<|L6R1 / L6R2|<10

[0529] Condition 7: 1<|L7R1 / L7R2|<5

[0530] When the center thickness (CT) of the lens is described based on the optical axis, the center thickness (CT4) of the fourth lens (404) may be the largest among the lenses, and the center thickness (CT1, CT5, CT7) of at least one of the first lens (401), the fifth lens (405), and the seventh lens (407) may be the smallest among the lenses. The difference between the maximum center thickness and the minimum center thickness of the lens may be within a range of 2 mm or more and 2.5 mm or less.

[0531] The center thickness of each lens may satisfy any one of the following conditions.

[0532] Condition 1: CT2, CT3, CT4, CT6 > CT1 = CT5 = CT7

[0533] Condition 2: CT4 > CT2 > CT1, CT3, CT5, CT6, CT7

[0534] Condition 3: CT2, CT4, CT6 > CT3 > CT1, CT5, CT7

[0535] Condition 4: CT4 > CT1, CT2, CT3, CT5, CT6, CT7

[0536] Condition 5: CT2, CT4 > CT6 > CT1, CT3, CT5, CT7

[0537] The center gaps (CG) between the lenses are described as follows: the center gap (CG1) between the first lens (401) and the second lens (402) may be the largest, and the center gap (CG3) between the third lens (403) and the fourth lens (404) and the center gap (CG6) between the sixth lens (406) and the seventh lens (407) may be at least one of the smallest distances. The difference between the largest center gap and the smallest center gap among the separated lens distances may be 3 mm or more, for example, in the range of 3 mm to 4 mm.

[0538] The center gap between each lens can satisfy the following conditions.

[0539] Condition 1: CG1 > CG2, CG3, CG4, CG5, CG6

[0540] Condition 2: CG1, CG5 > CG2 > CG3, CG4, CG6

[0541] Condition 3: CG1, CG2, CG4, CG5 > CG3 = CG6

[0542] Condition 4: CG1, CG2, CG5 > CG4 > CG3, CG4, CG6

[0543] Condition 5: CG1 > CG5 > CG2, CG3, CG4, CG6

[0544] Regarding the effective diameter, the lens with the largest effective diameter may be a lens made of a glass material. The lens with the largest effective diameter may be the fourth lens (404). Here, the effective diameter is the average of the effective diameter on the object side and the effective diameter on the sensor side of each lens. The lens surface with the largest effective diameter may be the seventh surface (S7) of the fourth lens (404). The lens with the smallest effective diameter may be the second lens (402). The lens surface with the smallest effective diameter may be the fourth surface (S4) of the second lens (402). The effective diameter of the plastic lens may be smaller than the effective diameter of the glass lens. The plastic lens may be disposed adjacent to the image sensor.

[0545] The effective diameter of each lens may satisfy any one of the following conditions.

[0546] Condition 1: CA_L4, CA_L7>CA_L1>CA_L2, CA_L3, CA_L5, CA_L6

[0547] Condition 2: CA_L1, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7>CA_L2

[0548] Condition 3: CA_L1, CA_L4, CA_L5, CA_L6, CA_L7>CA_L3>CA_L2

[0549] Condition 4: CA_L4>CA_L1, CA_L2, CA_L3, CA_L5, CA_L6, CA_L7

[0550] Condition 5: CA_L1, CA_L4, CA_L7>CA_L5>CA_L2, CA_L3, CA_L6

[0551] Condition 6: CA_L1, CA_L4, CA_L5, CA_L7>CA_L6>CA_L2, CA_L3

[0552] Condition 7: CA_L4>CA_L7>CA_L1, CA_L2, CA_L3, CA_L5, CA_L6

[0553] The refractive index is described as follows: the refractive index of the first lens (401) may be the highest among the lenses, exceeding 1.8, for example, 1.81 or higher. The second lens (402), the fourth lens (404), the sixth lens (406), and the seventh lens (407) may individually or collectively have the lowest refractive index among the lenses. For example, the refractive index of the second lens (402), the sixth lens (406), and the seventh lens (108) may be the smallest among the lenses, less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index may be 0.2 or greater. By providing a lens made of a plastic material having the lowest refractive index, the lens closest to the object and the lens made of a glass material having the highest refractive index, and providing a lens adjacent to the glass material lens and a lens adjacent to the image sensor (500), the incident efficiency can be increased, and the refractive power between the glass material lens and the plastic material lens can be controlled to guide light to the image sensor (500).

[0554] The refractive index of each lens may satisfy any one of the following conditions.

[0555] Condition 1: n1 > n2, n3, n4, n5, n6, n7

[0556] Condition 2: n1, n3, n5 > n2 = n4 = n6 = n7

[0557] Condition 3: n1>n3>n2, n4, n5, n6, n7

[0558] Condition 4: n1, n3 > n5 > n2, n4, n6, n7

[0559] When comparing Abbe numbers, at least one of the Abbe numbers of the second lens (402), the fourth lens (404), the sixth lens (406), and the seventh lens (407) may be the largest among the lenses and may be 50 or higher. The Abbe number of the fifth lens (405) may be the smallest among the lenses and may be 25 or lower. The difference between the maximum refractive index and the minimum Abbe number may be 40 or greater. By maximizing the Abbe number of the lens disposed at the center portion of the optical system (1000) and minimizing the Abbe number of the fifth lens (405) having a low refractive index adjacent to the image sensor (500), dispersion of light passing between the glass lens and the plastic lens may be controlled, and dispersion between the glass lens and the plastic lens may be increased, so that light can be guided to the image sensor (500).

[0560] The Abbe number of each lens may satisfy any one of the following conditions.

[0561] Condition 1: v2, v3, v4, v6, v7 > v1 > v5

[0562] Condition 2: v2 = v4 = v6 = v7 > v1, v3, v5

[0563] Condition 3: v2, v4, v6, v7 > v3 > v1, v5

[0564] Condition 4: v1, v2, v3, v4, v6, v7 > v5

[0565] The focal lengths (F1, F2, F5, F7) of lenses 1, 2, 5, and 7 (401, 402, 405, 407) may have a negative (-) sign. The lenses 1, 2, 5, and 7 (401, 402, 405, 407) may have a negative (-) refractive power. The focal lengths (F3, F4, F6) of the third lens, the fourth lens, and the sixth lens (403, 404, 406) may have a positive (+) sign. The third lens, the fourth lens, and the sixth lens (403, 404, 406) may have a positive (+) refractive power. The sensor side of the first lens (401) and the second lens (402) having negative (-) refractive power may be provided with a third lens (403) having positive (+) refractive power. Thus, light incident from the object side moves away from the optical axis direction and then converges again toward the optical axis direction, thereby forming a stable optical path.

[0566] In addition, the fourth lens (404) and the fifth lens (405) disposed adjacent to each other may satisfy the following conditions.

[0567] Condition 1: The refractive index of the lens with positive refractive power is less than the refractive index of the lens with negative refractive power.

[0568] Condition 2: Dispersion value of lens with positive refractive power > dispersion value of lens with negative refractive power

[0569] Here, among the plastic lenses, the fourth lens (404) has positive refractive power, and the fifth lens (405) has negative refractive power. According to conditions 1 and 2, the refractive index of the fourth lens (404) is smaller than the refractive index of the fifth lens (405), and the dispersion value of the fourth lens (404) is larger than the dispersion value of the fifth lens (405). Chromatic aberration occurring in the plastic lens can be corrected using the plastic lens. In addition, when the fourth lens (404) and the fifth lens (405) as continuously arranged plastic lenses satisfy the conditions of a refractive index difference of 0.1 or more and 0.15 or less and an Abbe number difference of 20 or more and 50 or less, chromatic aberration occurring in the plastic lens can be compensated using the plastic lens.

[0570] The optical system exhibits chromatic aberration, which is corrected using two lenses arranged in series or a cemented lens. As the temperature changes from low to high, the lenses repeatedly shrink and expand. Lenses made of the same material exhibit the same change in lens characteristics due to temperature changes, so correcting chromatic aberration between lenses made of the same material is effective even when the temperature changes. Therefore, in the fourth embodiment of the present invention, the fourth lens (404) and the fifth lens (405) can be used to correct chromatic aberration occurring in plastic lenses.

[0571] From the optical axis to the effective diameter area, the maximum distance between the two lenses with the largest Abbe number difference among the two adjacent lenses can be smaller than the maximum distance between other adjacent lens pairs. Here, the distance can refer to the distance between the two lenses from the optical axis to the effective diameter area. The two lenses with the largest Abbe number difference among the two adjacent lenses can be the fourth lens (404) and the fifth lens (405). The maximum distance value from the optical axis to the effective diameter area between the 8th surface (S8) of the sensor side surface of the fourth lens (404) and the 9th surface (S9) of the object side surface of the fifth lens (405) in the direction perpendicular to the optical axis can be smaller than the maximum distance value between any two adjacent lenses. This allows the distance between the two lenses made of plastic materials that are difficult to bond to be designed to be smaller, maximizing the Abbe number difference, thereby achieving the effect of reducing chromatic aberration to the same level as that of the bonded lenses even in the unbonded state.

[0572] When the focal lengths are compared as absolute values, the focal length of the first lens (401) may be the largest among the lenses and may be 100 or more and 120 or less. The focal length of the fifth lens (405) may be the smallest among the lenses, and the absolute value of the focal length of the fifth lens (405) may be 10 or more and 12 or less.

[0573] Since the first lens (401) has the largest focal length and the weakest refractive power among the lenses, the difference in Abbe number between the second lens (402) and the fourth lens (404) arranged on the sensor side of the first lens (401) does not need to be very large to achieve the effect of correcting chromatic aberration.

[0574] The absolute value of the focal length of each lens may satisfy any one of the following conditions.

[0575] Condition 1: |f1|>|f2|, |f3|, |f4|, |f5|, |f6|, |f7|

[0576] Condition 2: |f1|>|f2|>|f3|, |f4|, |f5|, |f6|, |f7|

[0577] Condition 3: |f1|, |f2|, |f7|>|f3|>|f4|, |f5|, |f6|

[0578] Condition 4: |f1|, |f2|, |f3|, |f7|>|f4|>|f5|, |f6|

[0579] Condition 5: |f1|, |f2|, |f3|, |f4|, |f6|, |f7|>|f5|

[0580] Condition 6: |f1|, |f2|, |f3|, |f4|, |f7|>|f6|>|f5|

[0581] Condition 7: |f1|, |f2|>|f7|>|f3|, |f4|, |f5|, |f6|

[0582] The thickness (T1) of the first lens (401) may be in the range of 1.5 times to 2 times the difference between the maximum thickness and the minimum thickness, wherein the center thickness (CT1) is the smallest and the edge thickness (ET1) is the largest. The thickness (T2) of the second lens (402) may have a maximum thickness in the range of 1 times to 1.5 times the minimum thickness. The second lens (402) may have a maximum thickness (CT2) at the center and a minimum thickness (ET2) at the edge. The thickness (T3) of the third lens (403) may be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 1 times to 1.5 times the minimum thickness. The thickness (T4) of the fourth lens (404) may be the largest at the center and the smallest at the edge, wherein the maximum thickness is in the range of 2 times to 2.5 times the minimum thickness. The thickness (T5) of the fifth lens (405) may be the smallest at the center and the largest at the edge, wherein the maximum thickness is in the range of 1.2 times to 1.7 times the minimum thickness. The thickness (T6) of the sixth lens (406) may be maximum at the center and minimum at the edge, wherein the maximum thickness is in the range of 1.2 times to 1.7 times the minimum thickness. The thickness (T7) of the seventh lens (407) may be minimum at the center and maximum at the edge, wherein the maximum thickness is in the range of 1.2 times to 1.7 times the minimum thickness.

[0583] The thickness of each lens may satisfy any one of the following conditions.

[0584] Condition 1: 0.5<CT1 / ET1<1, 1.5<ET1 / CT1<2

[0585] Condition 2: 1<CT2 / ET2<1.5, 0.5<ET2 / CT2<1

[0586] Condition 3: 0.5<CT3 / ET3<1, 1<ET3 / CT3<1.5

[0587] Condition 4: 2<CT4 / ET4<2.5, 0.1<ET4 / CT4<0.5

[0588] Condition 5: 0.5<CT5 / ET5<1, 1.2<ET5 / CT5<1.7

[0589] Condition 6: 1.2<CT6 / ET6<1.7, 0.5<ET6 / CT6<1

[0590] Condition 7: 0.5<CT7 / ET7<1, 1.2<ET7 / CT7<1.7

[0591] Condition 8: 1<ΣCT / ΣET<1.2, 0.5<ΣET / ΣCT<1

[0592] Among the gaps (G1 to G7) between the lenses, the first gap (G1) between the first lens (401) and the second lens (402) may have a maximum value at the center and a minimum value at the edge. The second gap (G2) between the second lens (402) and the third lens (403) may have a minimum value at the center and a maximum value at the edge. The third gap (G3) between the third lens (403) and the fourth lens (404) may have a maximum value at the edge and a minimum value at the center. The fourth gap (G4) between the fourth lens (404) and the fifth lens (405) may have a minimum value at the center and a maximum value at the edge. The fifth gap (G5) between the fifth lens (405) and the sixth lens (406) may have a maximum value at the center portion and a minimum value at the edge portion. The sixth gap (G6) between the sixth lens (406) and the seventh lens (407) may have a minimum value at the center portion and a maximum value at the edge portion.

[0593] Figure 42 、 Figure 44 and Figure 46 They are shown respectively Figure 37 The graphs show the diffraction MTF (Modulation Transfer Function) of the optical system at room temperature, low temperature and high temperature. These graphs show the modulation (brightness ratio) as a function of spatial frequency. Figure 42 、 Figure 44 and Figure 46 As shown, the deviation of the MTF between room temperature and low or high temperature in the fourth embodiment of the present invention may be less than 10%, ie, 7% or less.

[0594] Figure 43 、 Figure 45 and Figure 47 It shows Figure 37Graphs showing aberration characteristics of an optical system at room temperature, low temperature, and high temperature. Figure 43 、 Figure 45 and Figure 47 The aberration curve diagram in FIG shows the measured values ​​of spherical aberration (longitudinal spherical aberration), astigmatism field curve (Astigmatic Field Curve) and distortion (Distortion) from left to right. Figure 43 、 Figure 45 and Figure 47 In FIG, the X-axis may represent focal length (mm) and distortion (%), and the Y-axis may represent the height of the image. In addition, the graph for spherical aberration corresponds to light in wavelength bands of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, while the graphs for coma and distortion correspond to light in a wavelength band of about 546 nm. Figure 43 、 Figure 45 and Figure 47 In the aberration diagram of , the closer the curves at room temperature, low temperature, and high temperature are to the Y-axis, the better the aberration correction function is explained. The optical system (1300) according to the fourth embodiment shows that the measured values ​​are adjacent to the Y-axis in almost all areas. Therefore, the optical system (1300) according to the fourth embodiment has improved resolution and can achieve good optical performance not only in the central part of the field of view (FOV) but also in the peripheral area. Here, low temperature may refer to -20°C or below, for example, -20°C to -40°C, room temperature may refer to 22°C±5°C or 18°C ​​to 27°C, and high temperature may refer to 85°C or above, for example, 85°C to 405°C. Therefore, as Figure 43 、 Figure 45 and Figure 47 As shown, it can be seen that the brightness modulation from low temperature to high temperature decreases by less than 10%, such as 5% or less, or remains almost unchanged.

[0595] Table 12 compares 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. It can be seen that the rate of change in optical characteristics at low temperature is 5% or less, for example, 3% or less, relative to room temperature. It can be observed that the rate of change in optical characteristics at low temperature is 5% or less, for example, 3% or less, relative to room temperature.

[0596] [Table 12]

[0597] Room temperature Low temperature high temperature Low temperature / room temperature High temperature / room temperature EFL(F) 10.88 10.81 10.97 99.35％ 100.82％ BFL 3.40 3.40 3.41 100.00％ 100.29％ F# 1.64 1.63 1.65 99.39％ 100.60％ TTL 30.00 29.93 30.09 99.76％ 100.30％ FOV_D 54.51 54.90 54.03 100.71％ 99.11％

[0598] Therefore, as shown in Table 12, the change in optical characteristics due to temperature change from low to high temperature (e.g., the rate of change of effective focal length (EFL), TTL, BFL, F-number, and field of view (FOV_D)) is 10% or less, that is, 5% or less, for example, within the range of 0 to 5%. This design allows temperature compensation of the plastic lens even when using one or more plastic lenses, thereby preventing a decrease in the reliability of the optical characteristics.

[0599] The optical system of the fourth embodiment disclosed above can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can achieve good optical performance not only in the center of the field of view (FOV) but also in the peripheral area.

[0600] The optical systems (1000, 1100, 1200, 1300) according to the first to fourth embodiments described above can satisfy at least one or more of the following mathematical formulas. Therefore, the optical systems (1000, 1100, 1200, 1300) according to the first to fourth embodiments can have improved optical characteristics. For example, when the optical systems (1000, 1100, 1200, 1300) satisfy at least one mathematical formula, the optical systems (1000, 1100, 1200, 1300) can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can also have good optical performance not only in the central portion of the field of view (FOV) but also in the peripheral portion. Furthermore, the optical systems (1000, 1100, 1200, 1300) can achieve improved resolution. Furthermore, in the first to fourth embodiments described above, reference can be made to the thickness of the lens at its optical axis (OA) and the gap between adjacent lenses at their optical axis (OA) specified in the mathematical formula.

[0601] [Mathematical formula 1]

[0602] 30<|f1|<120

[0603] In Mathematical Formula 1, f1 represents the focal length of the first lens (101, 201, 301, 401). Compared with TTL, it can be set to have a short effective focal length to improve the performance of the optical system. If Mathematical Formula 1 is satisfied, light entering the first lens (101, 201, 301, 401) from the object side can be guided in a direction in which it converges on the optical axis. In addition, if the refractive power of the first lens (101, 201, 301, 401) closest to the object side is weak, the lens on the sensor side can correct chromatic aberration even if their Abbe numbers are significantly different. In addition, the entire optical system can have a stable structure that not only diffuses light but also converges light. In the first to fourth embodiments, Mathematical Formula 1 can preferably satisfy the condition of 50<|f1|<115.

[0604] [Mathematical formula 2]

[0605] 10<|F_LG1|<30

[0606] In Equation 2, |F_LG1| represents the focal length of the first lens group (LG1). The first lens group (LG1) is the lens group positioned on the object side relative to the aperture (stop). When the focal length of the first lens group (LG1) satisfies Equation 2, the optical system achieves excellent optical performance at a given field of view. In the first to fourth embodiments, preferably, 15 < |F_LG1| < 30 is satisfied.

[0607] [Mathematical formula 3]

[0608] 20<v1<60

[0609] In Mathematical Formula 3, v1 is the Abbe number of the first lens (101, 201, 301, 401). In the optical system (1000, 1100, 1200, 1300), the total focal length of the first lens group (LG1) has a negative (-) sign, and by setting the Abbe number of the first lens (101, 201, 301, 401) included in the first lens group (LG1) having a negative (-) focal length to a large value, an effect of reducing chromatic aberration of the lens can be achieved. In the first to third embodiments, Mathematical Formula 3 may preferably satisfy 50<v1<60, and in the fourth embodiment, Mathematical Formula 3 may preferably satisfy 20<v1<30.

[0610] [Formula 4]

[0611] 45<v2<60

[0612] In Mathematical Formula 4, v2 is the Abbe number of the second lens (102, 202, 302, 402). In the optical system (1000, 1100, 1200, 1300), the total focal length of the first lens group (LG1) has a negative (-) sign. Setting the Abbe number of the second lens (102, 202, 302, 402) included in the first lens group (LG1) having a negative (-) focal length to a large value can reduce chromatic aberration of the lens. In the first to fourth embodiments, Mathematical Formula 4 can preferably satisfy 50<v2<58.

[0613] [Formula 5]

[0614] 15<v5<25

[0615] In Mathematical Formula 5, v5 is the Abbe number of the fifth lens (105, 205, 305, 405). In the optical system (1000, 1100, 1200, 1300), the total focal length of the second lens group (LG2) has a positive (+) sign, and by setting the Abbe number of the fifth lens (105, 205, 305, 405) adjacent to the object side within the second lens group (LG2) and having a positive (+) focal length to be low, chromatic aberration of the lens disposed on the sensor side of the fifth lens (105, 205, 305, 405) can be reduced. In the first to fourth embodiments, Mathematical Formula 5 can preferably satisfy the condition 18<v5<22.

[0616] [Formula 6]

[0617] 0.1<CG1 / ΣCG<0.5

[0618] In Mathematical Formula 6, CG1 is the center gap between the first lens (101, 201, 301, 401) and the second lens (102, 202, 302, 402), and ΣCG is the sum of the gaps between adjacent lenses. When Mathematical Formula 6 is satisfied, light emitted from the first lens (101, 201, 301, 401), which has a significant impact on the entire optical system, sets the optical path entering the remaining lenses, and the optical system can achieve good optical performance at a set field of view and focal length. In the first to fourth embodiments, Mathematical Formula 6 can preferably satisfy 0.3<CG1 / ΣCG<0.5.

[0619] [Formula 7]

[0620] 0.1<CG1 / ΣCT<0.3

[0621] In Mathematical Formula 7, CG1 is the center gap between the first lens (101, 201, 301, 401) and the second lens (102, 202, 302, 402), and ΣCT is the sum of the center thicknesses of the lenses. When Mathematical Formula 7 is satisfied, light emitted from the first lens (101, 201, 301, 401), which has a significant influence on the entire optical system, sets an optical path for light entering the remaining lenses, and the optical system can achieve good optical performance at a set field of view and focal length. In the first to fourth embodiments, Mathematical Formula 7 may preferably satisfy 0.1 < ΣCT / ΣCG < 0.2.

[0622] [Formula 8]

[0623] 0.01<CG1 / TTL<0.2

[0624] In Mathematical Formula 8, CG1 is the center gap between the first lens (101, 201, 301, 401) and the second lens (102, 202, 302, 402), and can establish a distance (mm) from the center of the first surface (S1) of the first lens (101, 201, 301, 401) to the image surface of the image sensor (500) along the optical axis (OA), which is TTL. When Mathematical Formula 8 is satisfied, light emitted from the first lens (101, 201, 301, 401), which has a significant impact on the entire optical system, is guided to the remaining lenses, and the optical system can achieve good optical performance at a set field of view and focal length. In the first to fourth embodiments, Mathematical Formula 8 can preferably satisfy 0.1<CG1 / TTL<0.15.

[0625] [Formula 9]

[0626] 0.3<ΣCT / TTL<0.8

[0627] Mathematical formula 9 can establish a relationship between the sum of the center thicknesses (ΣCT) of the first lens to the seventh lens (101 to 107, 201 to 207, 301 to 307, 401 to 407) and the distance (mm) TTL from the center of the first surface (S1) of the first lens (101, 201, 301, 401) to the image surface of the image sensor (500) on the optical axis (OA). In order to reduce TTL, more light refraction is required. In order to increase light refraction, the focal length of the lens must be increased, and in order to increase the focal length, the lens must be made thicker. If the lower limit of mathematical formula 9 is not satisfied, the sum of the lens thicknesses decreases, resulting in weaker refractive power. If the upper limit of mathematical formula 9 is exceeded, the sum of the lens thicknesses increases excessively, resulting in an increase in TTL. In the first to fourth embodiments, mathematical formula 9 can preferably satisfy 0.5<ΣCT / TTL<0.8.

[0628] [Formula 10]

[0629] 0.1<ΣCG / TTL<0.5

[0630] Mathematical formula 10 can establish the relationship between the sum of the gaps (ΣCG) of adjacent lenses among the first lens to the seventh lens (101 to 107, 201 to 207, 301 to 307, 401 to 407) and TTL, which is the distance (mm) from the center of the first surface (S1) to the image surface of the image sensor (500) on the optical axis (OA). In order to reduce TTL, more light refraction is required. In order to increase light refraction, the focal length of the lens must be increased, and in order to increase the focal length, the lens must be made thicker. If the value is lower than the lower limit of mathematical formula 10, the total thickness of the lens is reduced, resulting in a refractive power weaker than the desired refractive power. If the upper limit of mathematical formula 10 is exceeded, the total thickness of the lens is excessively increased, resulting in an increase in TTL. In the first to fourth embodiments, mathematical formula 10 can preferably satisfy 0.1<ΣCG / TTL<0.3.

[0631] [Mathematical formula 11]

[0632] 3<ΣCT / ΣCG<4

[0633] In Equation 11, ΣCT is the sum of the center thicknesses of the lenses, and ΣCG is the sum of the gaps between adjacent lenses. When Equation 11 is satisfied, the optical system can achieve excellent optical performance at a specified field of view and focal length, while also reducing TTL. In the first to fourth embodiments, Equation 11 preferably satisfies 3 < ΣCT / ΣCG < 3.5.

[0634] [Mathematical formula 12]

[0635] 25<ΣAbb / ΣIndex<35

[0636] In Mathematical Formula 12, ΣAbb represents the sum of the Abbe numbers of each lens, and ΣIndex represents the sum of the refractive indices of each lens at the d-line. When Mathematical Formula 12 is satisfied, the optical system (1000, 1100, 1200, 1300) can achieve improved aberration characteristics and resolution. By setting the sum of the Abbe numbers and the sum of the refractive indices of the lenses according to Mathematical Formula 12, the optical characteristics can be controlled. In the first to fourth embodiments, it is preferred that Mathematical Formula 12 satisfies 28<ΣAbb / ΣIndex<33.

[0637] [Mathematical formula 13]

[0638] 1<ΣCT / ΣET<2

[0639] In Equation 13, ΣCT is the sum of the center thickness of the lens, and ΣET is the sum of the edge thicknesses, i.e., the sum of the end thicknesses of the lens' active area. When Equation 13 is satisfied, the optical system can achieve excellent optical performance at a specified field of view and focal length, while also reducing TTL. In the first to fourth embodiments, Equation 13 preferably satisfies 1 < ΣCT / ΣET < 1.3.

[0640] [Formula 14]

[0641] 0.5<CT1 / ET1<1.5

[0642] In Math 14, CT1 is the center thickness of the first lens (101, 201, 301, 401), and ET1 is the edge thickness of the first lens (101, 201, 301, 401). This allows for setting elements that affect the field of view of the optical system and elements that affect the effective focal length (EFL). In the first to fourth embodiments, Math 14 may preferably satisfy 0.7 < CT1 / ET1 < 1.2.

[0643] [Mathematical formula 15]

[0644] 0.5<GLCa_AVER / PLCa_AVER<1.5

[0645] In mathematical formula 15, GLCa_AVER represents the average effective diameter of the glass lens, and PLCa_AVER represents the average effective diameter of the plastic lens. The lens barrel in which the lens unit is provided has at least one inner barrel inside the lens barrel, and at least some of the plastic lenses included in the lens unit can be provided in the inner barrel. For plastic lenses, expansion at high temperatures is significant, requiring a larger space within the lens barrel. By setting the size of the effective diameter of the glass lens and the size of the effective diameter of the plastic lens in mathematical formula 15, the degradation of optical properties due to temperature changes can be suppressed, and the optical system (1000, 1100, 1200, 1300) can control the incident light and set elements that affect aberrations. In the first to fourth embodiments, mathematical formula 15 can preferably satisfy the condition 0.5<GLCa_AVER / PLCa_AVER<1.2.

[0646] [Mathematical formula 16]

[0647] 1<CA_L1S1 / CA_L1S2<2

[0648] In Math 16, CA_L1S1 represents the effective diameter of the first surface (S1) of the first lens (101, 201, 301, 401), and CA_L1S2 represents the effective diameter of the second surface (S2) of the first lens (101, 201, 301, 401). When Math 16 is satisfied, degradation of optical characteristics due to temperature changes can be suppressed, and the optical system (1000, 1100, 1200, 1300) can control incident light and set elements that affect aberrations. In the first to fourth embodiments, Math 16 can preferably satisfy 1<CA_L1S1 / CA_L1S2<1.5.

[0649] [Mathematical formula 17]

[0650] 0.5<CA_L1 / CA_L7<1.5

[0651] In Mathematical Formula 17, CA_L1 represents the effective diameter of the first lens (101, 201, 301, 401), and CA_L7 represents the effective diameter of the seventh lens (107, 207, 307, 407). The lens barrel in which the lens unit is mounted includes at least one inner barrel, and at least some of the plastic lenses included in the lens unit can be mounted in the inner barrel. The plastic lenses require more space within the lens barrel due to their high expansion at high temperatures. Therefore, when Mathematical Formula 17 is satisfied, degradation of optical characteristics due to temperature changes can be suppressed, and the optical system (1000, 1100, 1200, 1300) can control incident light and set elements that affect aberrations. Mathematical Formula 17 defines the relationship between the effective diameter of the first lens (101, 201, 301, 401) made of glass material and the effective diameter of the seventh lens (107, 207, 307) made of plastic material. In the first to fourth embodiments, Math. 17 may preferably satisfy 0.8<CA_L1 / CA_L7<1.2.

[0652] [Mathematical formula 18]

[0653] 1<CA_L1 / ImgH<2.5

[0654] Mathematical formula 18 can establish a relationship between the effective diameter (CA_L1) of the first lens (101, 201, 301, 401) and ImgH, which is the maximum diagonal length of the image sensor. When mathematical formula 18 is satisfied, TTL is suitable for automotive optical systems and the set field of view can be achieved. If the value is lower than the lower limit of mathematical formula 18, the effective diameter of the lens in the optical system (1000, 1100, 1200, 1300) becomes the maximum, causing the TTL to be too long. If the upper limit of mathematical formula 18 is exceeded, the field of view becomes too large compared to the field of view satisfied by the optical system (1000, 1100, 1200, 1300). In the first to fourth embodiments, mathematical formula 18 can preferably satisfy 1.8<CA_L1 / ImgH<2.2.

[0655] [Mathematical formula 19]

[0656] 1<CT_Max / CG_Max<2

[0657] In Equation 19, CT_Max is the maximum center thickness of a lens, and CG_Max is the maximum gap between adjacent lenses. When Equation 19 is satisfied, the optical system can achieve excellent optical performance at a given field of view and focal length, while also reducing TTL. In the first to fourth embodiments, it is preferred that Equation 19 satisfy the condition 1.2 < CT_Max / CG_Max < 2.

[0658] [Mathematical formula 20]

[0659] 1<CA_max / CA_min<2

[0660] In Equation 20, CA_max represents the maximum effective diameter between the object-side and sensor-side surfaces of the lens, and CA_Min represents the minimum effective diameter between the object-side and sensor-side surfaces of the lens. When Equation 20 is satisfied, the optical system can maintain optical performance while being dimensioned for a slim and compact structure. In the first to fourth embodiments, Equation 20 preferably satisfies the condition 1.2 < CA_max / CA_min < 1.5.

[0661] [Mathematical formula 21]

[0662] 1<CA_max / CA_Aver<2

[0663] In Equation 21, CA_max represents the maximum effective diameter of the lens's object-side and sensor-side surfaces, and CA_Aver represents the average effective diameter of the lens' object-side and sensor-side surfaces. When Equation 21 is satisfied, the optical system can maintain optical performance while being dimensioned for a slim and compact structure. In the first to fourth embodiments, Equation 21 preferably satisfies the condition 1 < CA_max / CA_Aver < 1.5.

[0664] [Mathematical formula 22]

[0665] 0.5<CA_min / CA_Aver<1

[0666] In Equation 22, CA_Min represents the minimum effective diameter between the object-side and sensor-side surfaces of the lens, and CA_Aver represents the average effective diameter between the object-side and sensor-side surfaces of the lens. When Equation 22 is satisfied, the optical system can maintain optical performance while being dimensioned for a slim and compact structure. In the first to fourth embodiments, Equation 22 preferably satisfies the condition 0.7 < CA_min / CA_Aver < 0.9.

[0667] [Mathematical formula 23]

[0668] 2<CA_max / ImgH<3

[0669] Mathematical formula 23 shows that CA_max represents the maximum effective diameter between the object side surface and the sensor side surface of the lens, and Imgh represents half of the maximum diagonal length of the image sensor (500). When mathematical formula 23 is satisfied, the optical system can maintain good optical performance and be sized for a slim and compact structure. In the first to fourth embodiments, mathematical formula 23 can preferably satisfy 2<CA_max / ImgH<2.5.

[0670] [Mathematical formula 24]

[0671] 25<TTL<32

[0672] In Math. 24, TTL (Total Track Length) represents the distance (mm) along the optical axis (OA) from the center of the first surface (S1) of the first lens (101, 201, 301, 401) to the image surface of the image sensor (500). When Math. 24 is satisfied, a suitable vehicle optical system can be provided. In the first to fourth embodiments, Math. 24 can preferably satisfy 28<TTL<31.

[0673] [Mathematical formula 25]

[0674] 5<ImgH<6

[0675] In Math 25, ImgH represents 1 / 2 of the maximum diagonal length of the image sensor (500). Math 25 can set the diagonal size (ImgH) of the image sensor (500) and provide a vehicle-specific sensor size for the optical system. In the first to fourth embodiments, Math 25 can preferably satisfy the condition 5<ImgH<5.5.

[0676] [Mathematical formula 26]

[0677] 3<BFL<4

[0678] In Mathematical Formula 26, BFL is the optical axis distance from the image sensor (500) to the center of the sensor side surface of the last lens. When Mathematical Formula 26 is satisfied, the installation space for the filter (600) and the cover glass can be ensured, and the assembly of the components can be improved by the gap between the image sensor (500) and the last lens, thereby improving the reliability of the connection. In the first to fourth embodiments, Mathematical Formula 26 can preferably satisfy 3<BFL<3.5. If BFL is lower than the range of Mathematical Formula 26, some light traveling toward the image sensor may not be transmitted to the image sensor, which may cause a reduction in resolution. If BFL exceeds the range of Mathematical Formula 26, stray light may enter, causing the aberration characteristics of the optical system to deteriorate.

[0679] [Mathematical formula 27]

[0680] 9<F<12

[0681] Mathematical formula 27 may allow the total focal length (F) to be set to suit the vehicle optical system. In the first to fourth embodiments, Mathematical formula 27 may satisfy 10<F<11.

[0682] [Mathematical formula 28]

[0683] 40<FOV_H<60

[0684] In Math 28, FOV_H represents the horizontal field of view (degrees) of the optical system (1000, 1100, 1200, 1300), and can provide a field of view suitable for an automotive optical system. Preferably, in the first to fourth embodiments, 45<FOV_H<50 can be satisfied.

[0685] [Mathematical formula 29]

[0686] 2<TTL / CA_max<3

[0687] In Mathematical Formula 29, CA_max refers to the maximum effective diameter (mm) among the object-side and sensor-side surfaces of the plurality of lenses, and TTL (Total Track Length) represents the distance (mm) along the optical axis (OA) from the vertex of the first surface (S1) of the first lens (101, 201, 301, 401) to the image surface of the image sensor (500). Mathematical Formula 29 can establish a relationship between the total optical axis length and the maximum effective diameter of the optical system, thereby providing an improved vehicle optical system. In the first to fourth embodiments, Mathematical Formula 29 can preferably satisfy the condition of 2.5 < TTL / CA_max < 2.7.

[0688] [Mathematical formula 30]

[0689] 5<TTL / ImgH<7

[0690] Mathematical formula 30 defines TTL (total track length) as the distance (mm) from the vertex of the first surface (S1) of the first lens to the image surface of the image sensor (500) along the optical axis (OA), and ImgH as half the maximum diagonal length of the image sensor (500). When mathematical formula 30 is satisfied, the optical system (1000, 1100, 1200, 1300) can have a TTL suitable for the vehicle-mounted image sensor (500), thereby providing improved image quality. In the first to fourth embodiments, mathematical formula 30 can preferably satisfy the condition of 5<TTL / ImgH<6.

[0691] [Mathematical formula 31]

[0692] 0.5<BFL / ImgH<1

[0693] Mathematical formula 31 defines BFL as the optical axis distance from the image sensor (500) to the center of the sensor-side surface of the last lens, and ImgH as half the maximum diagonal length of the image sensor (500). When mathematical formula 31 is satisfied, the optical system (1000, 1100, 1200, 1300) can ensure a BFL (back focal length) required to accommodate the size of the vehicle image sensor (500), set a gap between the last lens and the image sensor (500), and achieve good optical characteristics in both the center and peripheral areas of the field of view (FOV). In the first to fourth embodiments, mathematical formula 31 can preferably satisfy 0.5<BFL / ImgH<0.7.

[0694] [Mathematical formula 32]

[0695] 7<TTL / BFL<10

[0696] In Math 32, TTL (Total Track Length) refers to the distance (mm) along the optical axis (OA) from the vertex of the first surface (S1) of the first lens (101, 201, 301, 401) to the image surface of the image sensor (500). BFL represents the optical axis distance from the image sensor (500) to the center of the sensor-side surface of the last lens. If Math 32 is satisfied, the optical system (1000, 1100, 1200, 1300) can ensure BFL. In the first to fourth embodiments, Math 32 can preferably satisfy 7<TTL / BFL<9.

[0697] [Mathematical formula 33]

[0698] 2<TTL / F<3

[0699] Mathematical formula 33 defines TTL (total track length) as the distance (mm) from the vertex of the first surface (S1) of the first lens to the image surface of the image sensor (500) along the optical axis (OA). F represents the effective focal length of the optical system. Therefore, an optical system for a driver assistance system can be provided. When the optical system (1000, 1100, 1200, 1300) according to the embodiment satisfies mathematical formula 33, the optical system (1000, 1100, 1200, 1300) can have an appropriate focal length within the set TTL range and maintain the appropriate focal length even when the temperature changes from low to high, thereby providing an optical system capable of forming an image. If the value is lower than the lower limit of mathematical formula 33, it is necessary to increase the refractive power of the lens, which makes it difficult to correct spherical aberration or distortion aberration. If the value exceeds the upper limit of mathematical formula 33, the effective diameter or TTL of the lens may become longer, resulting in a problem that the imaging lens system becomes larger. In the first to fourth embodiments, mathematical formula 33 can preferably satisfy the condition 2.5<TTL / F<3.

[0700] [Mathematical formula 34]

[0701] 3<F / BFL<4

[0702] In Mathematical Formula 34, F is the effective focal length of the optical system, and BFL is the optical axis distance from the image sensor (500) to the center of the sensor-side surface of the last lens. When Mathematical Formula 34 is satisfied, the optical system (1000, 1100, 1200, 1300) has a set field of view and an appropriate focal length, and can be provided as a vehicle optical system. In addition, the optical system (1000, 1100, 1200, 1300) can minimize the gap between the last lens and the image sensor (500), thereby achieving good optical characteristics in the peripheral area of ​​the field of view (FOV). In the first to fourth embodiments, Mathematical Formula 34 can preferably satisfy the condition 3<F / BFL<3.5.

[0703] [Mathematical formula 35]

[0704] 2<F / ImgH<3

[0705] In Math 35, F is the effective focal length of the optical system, and ImgH is 1 / 2 of the maximum diagonal length of the image sensor (500). This optical system (1000, 1100, 1200, 1300) can have improved aberration characteristics in terms of the size of the vehicle image sensor (500). In the first to fourth embodiments, Math 35 can preferably satisfy 2<F / ImgH<2.5.

[0706] [Mathematical formula 36]

[0707]

[0708] In Math 36, Z may represent the distance from any position on the aspheric surface to the vertex of the aspheric surface in the direction of the optical axis. Y may represent the distance from any point on the aspheric surface to the optical axis, perpendicular to the optical axis. c may represent the curvature of the lens, and K may represent the conic constant. In addition, A, B, C, D, E, and F may represent aspheric surface constants.

[0709] The optical system (1000, 1100, 1200, 1300) according to the first to fourth embodiments can satisfy at least one or more of mathematical formulas 1 to 36. In this case, the optical system (1000, 1100, 1200, 1300) can have improved optical characteristics. In detail, when the optical system (1000, 1100, 1200, 1300) satisfies at least one or more of mathematical formulas 1 to 36, the optical system (1000, 1100, 1200, 1300) has improved resolution and can improve aberration and distortion characteristics. In addition, the optical system (1000, 1100, 1200, 1300) can ensure the back focal length (BFL) required for applying the on-board image sensor (500), compensate for the degradation of optical performance caused by temperature changes, and minimize the gap between the last lens and the image sensor (500), thereby achieving good optical performance in both the center and peripheral areas of the field of view (FOV).

[0710] Table 13 shows the results of the above-mentioned Mathematical Formulas 1 to 35 for the optical systems (1000, 1100, 1200, 1300) according to the embodiment. Referring to Table 13, it can be seen that the optical systems (1000, 1100, 1200, 1300) satisfy at least one, two or more, or three or more of Mathematical Formulas 1 to 35. In detail, the optical systems (1000, 1100, 1200, 1300) according to the embodiment satisfy all of Mathematical Formulas 1 to 35. Therefore, the optical systems (1000, 1100, 1200, 1300) can have good optical performance and excellent optical characteristics in both the center and peripheral areas of the field of view (FOV).

[0711] [Table 13]

[0712]

[0713]

[0714]

[0715] Figure 49 1 is an example of a plan view of a vehicle to which a camera module or an optical system according to an embodiment of the present invention is applied. Figure 49 According to an embodiment of the present invention, a vehicle camera system includes an image generating unit (11), a first information generating unit (12), a second information generating unit (21, 22, 23, 24, 25, 26) and a control unit (14). The image generating unit (11) may include at least one camera module (31) provided on her or his vehicle, and may capture the front of the vehicle and / or the driver to generate a front view image of her or his vehicle or an interior view image of her or his vehicle. The video generating unit (11) may use the camera module (31) to capture not only the front of her or his vehicle but also the surroundings of her or his vehicle in one or more directions to generate a video of the surroundings of her or his vehicle. Here, the front view and the surrounding view may be digital images and may include color images, black and white images and infrared images. In addition, the front view and the surrounding view may include still images and videos. The image generating unit (11) provides the driver image, the front view and the surrounding view to the control unit (14). Next, the first information generating unit (12) may include at least one radar and / or camera device provided on the vehicle, and detects the front of the vehicle to generate first detection information. Specifically, the first information generating unit (12) is placed on the vehicle, and detects the position and speed of the vehicle located in front of the vehicle, the presence and position of pedestrians, etc. to generate the first detection information.

[0716] The first information generating unit (12) can use the first detection information generated by the first information generating unit (12) to control the vehicle to maintain a constant distance between her or his vehicle and the vehicle in front, and can enhance the stability of the vehicle operation in specific situations such as when the driver wants to change the driving lane of her or his vehicle or when reversing to park. The first information generating unit (12) provides the first detection information to the control unit (14). The second information generating unit (21, 22, 23, 24, 25, 26) generates second detection information by detecting each side of her or his vehicle based on the front video generated by the video generating unit (11) and the first detection information generated by the first information generating unit (12). Specifically, the second information generating unit (21, 22, 23, 24, 25, 26) can include at least one radar and / or camera device set on her or his vehicle, and can detect the position and speed of vehicles located on the side of her or his vehicle or capture images. Here, the second information generating units (21, 22, 23, 24, 25, 26) may be provided at the front corners, rearview mirrors, and rear center and rear corners of her or his vehicle.

[0717] Among these vehicle camera systems, at least one information generating unit may be equipped with the optical system described in the above-mentioned embodiment and a camera module having the optical system, and may provide the user with information obtained through the front, rear, each side or corner area of ​​her or his vehicle or process the information to protect the vehicle and objects from being affected by autonomous driving or surrounding safety.

[0718] The optical system of the camera module according to an embodiment of the present invention can be installed in multiple units within a vehicle to meet safety regulations, enhance autonomous driving functions, and increase convenience. In addition, the optical system of the camera module is used in the vehicle as a component for controlling systems such as lane keeping assist systems (LKAS), lane departure warning systems (LDWS), and driver monitoring systems (DMS). This vehicle camera module can provide stable optical performance even under varying ambient temperatures and provides a cost-competitive module, thereby ensuring the reliability of vehicle components.

[0719] The features, structures, and effects described in the above embodiments are included in at least one embodiment of the present invention and are not necessarily limited to a single embodiment. In addition, the features, structures, and effects shown in each embodiment can be combined or modified by those skilled in the art to form other embodiments. Therefore, the content related to such combinations and modifications should be interpreted as falling within the scope of the present invention.

[0720] In addition, although the above description focuses on the embodiments, these are merely examples and do not limit the present invention. It will be understood by those skilled in the art that various modifications and applications not explicitly described herein are possible within the scope of the present invention, as long as they do not deviate from the basic features of the embodiments. For example, each component specifically shown in the embodiments may be modified. Any differences associated with such modifications and applications should all be interpreted as falling within the scope of the present invention as defined in the appended claims.

Claims

1. An optical system comprising first to seventh lenses arranged along an optical axis, wherein: The first lens has negative (-) refractive power; the second lens has 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; and the seventh lens has negative (-) refractive power, and wherein an aperture is provided between the second lens and the third lens, and among the first to seventh lenses, the third lens has the largest thickness on the optical axis.

2. The optical system according to claim 1, wherein At least one of the first lens and the third lens is made of glass, and at least one of the second lens and the fourth to seventh lenses is made of plastic.

3. The optical system according to claim 1, wherein: On the optical axis, the sixth lens has a convex shape on both surfaces, and on the optical axis, the seventh lens has a meniscus shape that is convex toward the object side.

4. The optical system according to claim 1, wherein: An absolute value of the focal length of the first lens is the largest among the first to seventh lenses.

5. The optical system according to claim 1, wherein From the optical axis to the effective diameter area, a maximum distance between two adjacent lenses having a maximum Abbe number difference is smaller than a maximum distance between the other two adjacent lenses.

6. The optical system according to claim 1, wherein: The fourth lens and the fifth lens have the largest Abbe number difference among adjacent lenses.

7. The optical system according to any one of claims 1 to 6, satisfying the following conditions: <Condition> 40<FOV_H<60. (In the above conditions, FOV_H refers to the horizontal field of view (horizontality) of the optical system.) 8. The optical system according to any one of claims 1 to 6, satisfying the following conditions: <Condition> 0.3 < CG1 / ΣCG < 0.

5. (In the conditions, CG1 is the distance between the first lens and the second lens on the optical axis, and ΣCG is the sum of the gaps between adjacent lenses on the optical axis.) 9. The optical system according to any one of claims 1 to 6, satisfying the following conditions: <Condition>5<TTL / ImgH<7. (In the conditions, TTL is the distance from the vertex of the object-side surface of the first lens to the image surface of the image sensor along the optical axis, and ImgH is 1 / 2 of the maximum diagonal length of the image sensor.) 10. An optical system comprising first to seventh lenses arranged along an optical axis, wherein: The second lens has negative (-) refractive power; the third lens has positive (+) refractive power; the fourth lens has positive (+) refractive power; The fifth lens element has negative (-) refractive power; the sixth lens element has positive (+) refractive power; The seventh lens has negative (-) refractive power, and the effective diameter of the second lens is the smallest among the first to seventh lenses, and the effective diameter of the fourth lens is the largest among the first to seventh lenses.

Images