Optical system and camera module

Abstract

The optical system according to an embodiment of the present invention includes first to seventh lenses disposed along an optical axis, wherein the first lens has negative (−) refractive power, the second lens has negative (−) refractive power, the fifth lens has positive (+) refractive power, the sixth lens has negative (−) refractive power, the seventh lens has positive (+) refractive power, and the thickness of the third lens is the greatest among the first to seventh lenses on the optical axis.

Description

Optical system and camera module

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

[0002] ADAS (Advanced Driving Assistance System) is an advanced driver assistance system that assists the driver in driving. It consists of sensing the situation ahead, judging the situation based on the sensed results, and controlling the vehicle's behavior based on the situation judgment. For example, ADAS sensor devices detect a vehicle ahead and recognize lanes. After the target lane, target speed, and forward target are determined, the vehicle's ESC (Electrical Stability Control), EMS (Engine Management System), and MDPS (Motor Driven Power Steering) are controlled. Representative examples of ADAS can be implemented as automatic parking systems, low-speed city driving assistance systems, and blind spot warning systems.

[0003] Sensor devices for detecting the situation ahead in ADAS include GPS sensors, laser scanners, forward radar, Lidar, etc., and the most representative one is a camera for taking pictures of the front, rear, and sides of the vehicle.

[0004] These cameras can be placed outside or inside a vehicle to detect the vehicle's surroundings. Furthermore, the cameras can be placed inside the vehicle to detect the driver and passengers. For example, the camera can photograph the driver from a position adjacent to the driver and detect the driver's health, drowsiness, and drinking status. Furthermore, the camera can photograph the passenger from a position adjacent to the passenger and detect the passenger's sleepiness, health, and other conditions, and provide the driver with information about the passenger.

[0005] In particular, the most crucial element for capturing an image from a camera is the imaging lens that forms the image. Recently, interest in high-performance features such as high image quality and high resolution has been increasing, and research is being conducted on optical systems comprising multiple lenses to achieve these features. However, there is a problem in that the characteristics of the optical system change when the camera is exposed to harsh environments, such as high temperature, low temperature, moisture, or high humidity, either inside or outside the vehicle. In this case, the camera faces the problem of difficulty in uniformly achieving excellent optical and aberration characteristics.

[0006] Therefore, a new optical system and camera that can solve the above-described problems are required.

[0007] The present invention seeks to provide an optical system and camera module having improved optical characteristics.

[0008] The present invention seeks to provide an optical system and camera module having excellent optical performance in low-temperature to high-temperature environments.

[0009] The present invention seeks to provide an optical system and camera module capable of preventing or minimizing changes in optical properties over a wide temperature range.

[0010] In order to solve the above technical problem, an optical system according to the present embodiment includes 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 fifth lens has positive (+) refractive power, the sixth lens has negative (-) refractive power, and the seventh lens has positive (+) refractive power, and among the first to seventh lenses, the thickness of the third lens is the largest on the optical axis.

[0011] An aperture is arranged between the third lens and the fourth lens, and at least one lens adjacent to the aperture may be made of glass.

[0012] The third lens may have positive (+) refractive power, and the fourth lens may have positive (+) refractive power.

[0013] The thickness of the third lens on the optical axis may be greater than the distance between the third lens and the fourth lens.

[0014] Among the first to seventh lenses on the optical axis, the thicknesses of the second lens and the sixth lens may be the smallest.

[0015] The above sixth lens may have a concave shape on both sides.

[0016] The following condition can be satisfied. <Condition> 18 < TTL < 25 (In the above condition, TTL means the distance from the object side of the first lens to the upper surface of the image sensor on the optical axis.)

[0017] The following condition can be satisfied. <Condition> 75 < FOV_H < 90 (In the above condition, FOV_H means the horizontal angle of view of the optical system.)

[0018] In order to solve the above technical problem, an optical system according to another embodiment of the present invention includes first to seventh lenses arranged along an optical axis, wherein the third lens has positive (+) refractive power, the fourth lens has positive (+) refractive power, the fifth lens has positive (+) refractive power, the sixth lens has negative (-) refractive power, and the seventh lens has positive (+) refractive power, and a thickness of the third lens on the optical axis is greater than a distance between the third lens and the fourth lens.

[0019] An aperture is arranged between the third lens and the fourth lens, at least one lens adjacent to the aperture is made of glass, and the first lens may be made of glass.

[0020] The fifth lens may have a convex shape on both sides, and the sixth lens may have a concave shape on both sides.

[0021] The distance between the first lens and the second lens on the optical axis may be greater than the thickness of the fifth lens.

[0022] The following condition can be satisfied. <Condition> 0.1 < ΣCG / ΣCT < 0.7 (In the above condition, ΣCG is the sum of the spacing between adjacent lenses in the optical system, and ΣCT is the sum of the central thicknesses of each lens in the optical system.)

[0023] The following condition can be satisfied. <Condition> 0.1 < CG1 / ΣCT < 0.5 (In the above condition, CG1 is the center spacing between the first lens and the second lens, and ΣCT is the sum of the center thicknesses of each lens in the optical system.)

[0024] The following condition can be satisfied. <Condition> 5 < F < 6 (In the above condition, F is the total focal length of the optical system.)

[0025] In order to solve the above technical problem, an optical system according to the present embodiment includes 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 fifth lens has positive (+) refractive power, the sixth lens has negative (-) refractive power, and the seventh lens has positive (+) refractive power, the fifth lens has a convex shape on both sides, and the sixth lens has a concave shape on both sides.

[0026] The above fourth lens may have a meniscus shape with a concave object side.

[0027] Among the first to seventh lenses, the effective diameter of the fourth lens may be the smallest.

[0028] The effective diameter of the third lens may be larger than the effective diameter of the fourth lens.

[0029] An aperture is arranged between the third lens and the fourth lens, and at least one lens adjacent to the aperture may be made of glass.

[0030] The above seventh lens may have a biconvex shape.

[0031] The following condition can be satisfied. <Condition> 2 < TTL / ImgH < 5 (In the above condition, TTL is the distance from the object side of the first lens to the upper surface of the image sensor on the optical axis, and ImgH is the maximum diagonal length of the image sensor.)

[0032] The following condition can be satisfied. <Condition> 110 < FOV_H < 130 (In the above condition, FOV_H means the horizontal angle of view of the optical system.)

[0033] In order to solve the above technical problem, an optical system according to another embodiment of the present invention includes first to seventh lenses arranged along an optical axis, wherein the third lens has positive (+) refractive power, the fourth lens has positive (+) refractive power, the fifth lens has positive (+) refractive power, the sixth lens has negative (-) refractive power, and the seventh lens has positive (+) refractive power, and among the first to seventh lenses, the effective diameter of the first lens may be the largest, and the effective diameter of the fourth lens may be the smallest.

[0034] The first lens and the third lens may be made of glass.

[0035] Among the first to seventh lenses on the optical axis, the thickness of the third lens may be the largest.

[0036] Among the distances between adjacent lenses on the optical axis, the distance between the fifth lens and the sixth lens may be the smallest.

[0037] The following condition can be satisfied. <Condition> 0.1 < CG1 / ΣCG < 1 (In the above condition, CG1 is the center spacing between the first lens and the second lens, and ΣCG is the sum of the spacings between adjacent lenses in the optical system.)

[0038] The following condition can be satisfied. <Condition> 8.5 < ImgH < 9.5 (In the above condition, ImgH is the maximum diagonal length of the image sensor.)

[0039] The following condition can be satisfied. <Condition> 0.1 < CT3 / F < 1 (In the above condition, CT3 is the central thickness of the third lens, and F is the total focal length of the optical system.)

[0040] An optical system and camera module according to an embodiment may have improved optical characteristics. Specifically, in the optical system according to an embodiment, a plurality of lenses may have set thicknesses, refractive powers, and spacings from adjacent lenses. Accordingly, the optical system and camera module according to the embodiment may have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. within a set field of view range, and may have good optical performance in the periphery of the field of view.

[0041] In addition, the optical system and camera module according to the embodiment can have good optical performance in a low temperature to high temperature range (-40℃ to 105℃). Specifically, a plurality of lenses included in the optical system can have set materials, refractive powers, and refractive indices. Accordingly, when the refractive index of each lens changes according to a temperature change and the focal length of each lens changes due to this, mutual compensation can be made by the plastic lens and the glass lens. That is, the optical system can effectively perform refractive power distribution in a low temperature to high temperature range, and can prevent or minimize changes in optical characteristics in a low temperature to high temperature range. Therefore, the optical system and camera module according to the embodiment can maintain improved optical characteristics in various temperature ranges.

[0042] Furthermore, the optical system and camera module according to the embodiment can satisfy the set angle of view and implement excellent optical characteristics through a combination of plastic and glass lenses. This allows the optical system to provide a slimmer vehicle camera module. Accordingly, the optical system and camera module can be used in various applications and devices, and can maintain excellent optical characteristics even in harsh temperature environments, such as when exposed to the exterior of a vehicle or in the high temperatures of a vehicle interior during the summer.

[0043] FIG. 1 is a side cross-sectional view of an optical system and a camera module having the same according to a first embodiment.

[0044] FIG. 2 is a table showing aspherical coefficients of lenses in the optical system according to the first embodiment of FIG. 1.

[0045] FIG. 3 is a table showing the Sag values ​​of the lens surfaces of the first to seventh lenses in the optical system according to the first embodiment of FIG. 1.

[0046] FIG. 4 is a graph showing data on the diffraction MTF (Modulation Transfer Function) at room temperature of the optical system of FIG. 1 according to the first embodiment.

[0047] FIG. 5 is a graph showing data on the diffraction MTF at low temperatures of the optical system of FIG. 1 according to the first embodiment.

[0048] FIG. 6 is a graph showing data on the diffraction MTF at high temperatures of the optical system of FIG. 1 according to the first embodiment.

[0049] Fig. 7 is a graph showing data on the aberration characteristics of the optical system of Fig. 1 according to the first embodiment at room temperature.

[0050] Fig. 8 is a side cross-sectional view of an optical system and a camera module having the same according to a second embodiment.

[0051] Fig. 9 is a table showing the aspherical coefficients of lenses in the optical system according to the second embodiment of Fig. 8.

[0052] Fig. 10 is a table showing the Sag values ​​of the lens surfaces of the first to seventh lenses in the optical system according to the second embodiment of Fig. 8.

[0053] Fig. 11 is a graph showing data on the diffraction MTF (Modulation Transfer Function) at room temperature of the optical system of Fig. 8 according to the second embodiment.

[0054] Fig. 12 is a graph showing data on the diffraction MTF at low temperatures of the optical system of Fig. 8 according to the second embodiment.

[0055] Fig. 13 is a graph showing data on the diffraction MTF at high temperatures of the optical system of Fig. 8 according to the second embodiment.

[0056] Fig. 14 is a graph showing data on the aberration characteristics of the optical system of Fig. 8 at room temperature according to the second embodiment.

[0057] Fig. 15 is a side cross-sectional view of an optical system and a camera module having the same according to a third embodiment.

[0058] Fig. 16 is a table showing the aspherical coefficients of lenses in the optical system according to the third embodiment of Fig. 15.

[0059] Fig. 17 is a table showing the Sag values ​​of the lens surfaces of the first to seventh lenses in the optical system according to the third embodiment of Fig. 15.

[0060] Fig. 18 is a graph showing data on the diffraction MTF (Modulation Transfer Function) at room temperature of the optical system of Fig. 15 according to the third embodiment.

[0061] Fig. 19 is a graph showing data on the diffraction MTF at low temperatures of the optical system of Fig. 15 according to the third embodiment.

[0062] Fig. 20 is a graph showing data on the diffraction MTF at high temperatures of the optical system of Fig. 15 according to the third embodiment.

[0063] Fig. 21 is a graph showing data on the aberration characteristics of the optical system of Fig. 15 at room temperature according to the third embodiment.

[0064] Fig. 22 is a side cross-sectional view of an optical system and a camera module having the same according to the fourth embodiment.

[0065] Fig. 23 is a table showing the aspherical coefficients of lenses in the optical system according to the fourth embodiment of Fig. 22.

[0066] Fig. 24 is a table showing the Sag values ​​of the lens surfaces of the first to seventh lenses in the optical system according to the fourth embodiment of Fig. 22.

[0067] Fig. 25 is a graph showing data on the diffraction MTF (Modulation Transfer Function) at room temperature of the optical system of Fig. 22 according to the fourth embodiment.

[0068] Fig. 26 is a graph showing data on the diffraction MTF at low temperatures of the optical system of Fig. 22 according to the fourth embodiment.

[0069] Fig. 27 is a graph showing data on the diffraction MTF at high temperatures of the optical system of Fig. 22 according to the fourth embodiment.

[0070] Fig. 28 is a graph showing data on the aberration characteristics of the optical system of Fig. 22 at room temperature according to the fourth embodiment.

[0071] Figures 29 and 30 are cross-sectional views of lens modules for the first to fourth embodiments.

[0072] Fig. 31 is an example of a vehicle having an optical system according to the first to fourth embodiments of the invention.

[0073] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0074] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0075] In addition, terms (including technical and scientific terms) used in this embodiment may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which this embodiment belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0076] Additionally, the terms used in this embodiment are for the purpose of describing the embodiments and are not intended to limit the present invention.

[0077] In this specification, the singular may also include the plural unless specifically stated otherwise in the phrase, and when it is described as “A and / or at least one (or more) of B, C”, it may include one or more of all combinations that can be combined with A, B, C.

[0078] Additionally, in describing the components of this embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and are not intended to limit the nature, order, or sequence of the components.

[0079] And, when a component is described as being 'connected', 'coupled', or 'connected' to another component, it may include not only cases where the component is 'connected', 'coupled', or 'connected' directly to the other component, but also cases where the component is 'connected', 'coupled', or 'connected' by another component between the component and the other component.

[0080] Additionally, when described as being formed or arranged "above" or "below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when expressed as "above" or "below," the meaning may include not only the upward direction but also the downward direction based on one component.

[0081] In the description of the invention, the "object side" may mean a surface of the lens facing the object side with respect to the optical axis (OA), and the "sensor side" may mean a surface of the lens facing the imaging surface (image sensor) with respect to the optical axis. The "object side" may be the "object side," and the "sensor side" may be the "image side." A convex surface of a lens may mean a convex shape in the optical axis or the paraxial region, and a concave surface of a lens may mean a concave shape in the optical axis or the paraxial region. The radius of curvature, the center thickness, and the optical axis spacing between lenses described in the table for lens data may mean values ​​(unit: mm) in the optical axis. The vertical direction may mean a direction perpendicular to the optical axis, and the end of a lens or lens surface may mean the end of an effective area of ​​a lens through which incident light passes. The size of the effective diameter of the lens surface may have a measurement error of up to ±0.4 mm depending on the measurement method, etc. The above-mentioned near-axis region refers to a very narrow region near the optical axis, and is a region where the distance that a light ray falls from the optical axis (OA) is almost 0. Hereinafter, the meaning of the optical axis may include the center of each lens or a very narrow region near the optical axis.

[0082]

[0083] As shown in FIGS. 1, 8, 15, and 22, 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 modules having the same may be mounted inside or outside a vehicle to monitor the driver or sense external objects or lanes. The material of the lenses may be selected from glass or plastic, and the coefficient of linear expansion of glass material is lower than that of plastic material. Accordingly, glass lenses are employed to suppress changes in the focal imaging position due to temperature changes. However, glass lenses are expensive compared to plastic lenses, and there is a problem that it is difficult to meet the demand for low cost.

[0084] Accordingly, the lenses within the optical system (1000, 1100, 1200, 1300) require a mixed configuration of glass lenses and plastic lenses. By employing these plastic lenses, the optical system (1000, 1100, 1200, 1300) can provide weight reduction and cost reduction by reducing the thickness of the plastic lenses, and the plastic lenses can provide good correction for various aberrations such as spherical aberration and chromatic aberration. In addition, since the plastic lenses can provide aspherical lenses, the distortion portion in the periphery can be minimized.

[0085] The optical system (1000, 1100, 1200, 1300) may include n lenses, where the n-th lens may be the last lens adjacent to the image sensor (600), and the (n-1)-th lens may be the lens closest to the last lens. n is an integer greater than or equal to 5, for example, 5 to 8. The n lenses may have a ratio of glass lenses to plastic lenses in the range of 2:5 to 3:5.

[0086] Within the optical system (1000, 1100, 1200, 1300), at least one lens closest to the object may be made of glass. Two or fewer lenses closest to the object, for example, one lens, may be made of glass. Since the rate of contraction and expansion of glass lenses due to temperature changes is smaller than that of plastic lenses, the glass lenses may be arranged in an area adjacent to the outside within the lens barrel. In addition, if the lens closest to the object is made of glass, the occurrence of scratches due to contact with external structures can be minimized.

[0087] At least one lens disposed adjacent to the stop within the optical system (1000, 1100, 1200, 1300) may be made of glass. The lens disposed closest to the stop on the object side of the stop may be made of glass. Since the lens disposed adjacent to the stop has a large influence in the optical system (1000, 1100, 1200, 1300), the glass lens may be disposed so that the rate of change in contraction and expansion due to temperature change is small.

[0088] At least one lens closest to the image sensor (600) within the optical system (1000, 1100, 1200, 1300) may be made of plastic. For example, at least two lenses closest to the image sensor (600) may be made of plastic, and preferably, at least two lenses adjacent to the image sensor (600) may be made of plastic. That is, since the n-th and n-1-th lenses in the optical system (1000, 1100, 1200, 1300) are arranged as plastic lenses, various aberrations can be corrected for the light incident on the image sensor (600).

[0089] Within the optical system (1000, 1100, 1200, 1300), plastic lenses can be arranged in series, and glass lenses can be arranged in series. Within the optical system (1000, 1100, 1200, 1300), plastic lenses can be arranged between glass lenses. Within the optical system (1000, 1100, 1200, 1300), glass lenses can be arranged between plastic lenses.

[0090]

[0091] Each lens (101-107, 201-207, 301-307, 401-407) can have an object side surface and a sensor side surface. The optical system can have more lenses with aspherical sensor sides and aspherical object sides than the number of plastic lenses. The optical system can have fewer lenses with spherical sensor sides and spherical object sides than the number of lenses with aspherical surfaces on both sides. The optical system (1000, 1100, 1200, 1300) has more aspherical lenses than spherical lenses, so it can correct various aberrations.

[0092] Among the lenses of the optical system (1000, 1100, 1200, 1300), the lens with the highest refractive index can be positioned adjacent to the aperture. The highest refractive index can be 1.8 or higher. The chromatic dispersion of light incident on the lens with the highest refractive index can be increased, and the center thickness can be made thinner than the edge thickness. In addition, since the lens with the highest refractive index is positioned on the object side, it is easy to change the radius of curvature of the second and subsequent lenses, and the center thickness can be increased.

[0093]

[0094] Within the optical system (1000, 1100, 1200, 1300), a lens having a maximum effective diameter can be placed at the center of the object side and the sensor side. The effective diameter of the lens can increase and then decrease as it moves from the object side to the sensor side. The effective diameter of the lens can decrease and then increase and then decrease again as it moves from the object side to the sensor side. Through this, since the light incident on the optical system (1000, 1100, 1200, 1300) is structured to move away from the optical axis and then return to the optical axis, the optical system (1000, 1100, 1200, 1300) can form a stable optical path.

[0095] The effective diameter may be the diameter of the effective area where effective light is incident on each lens. The effective diameter is the length in the direction (X, Y) orthogonal to the optical axis, and is the average of the effective diameter on the object side of each lens and the effective diameter on the sensor side. The "diameter of the lens surface" may mean the "effective diameter of the lens." The "diameter of the lens" may be the diameter of the entire lens including the flange portion of the lens in addition to the effective area of ​​the lens. Although the flanges of the lenses are not illustrated in FIGS. 1, 8, 15, and 22, the flanges may be portions that protrude perpendicular to the optical axis from the side surfaces of the lenses so that the lenses are coupled to the barrel. The flanges may not receive effective light. A spacer may be additionally arranged between the flanges of different lenses so that the lenses are coupled to the barrel.

[0096] Each of the lenses (101-107, 201-207, 301-307, 401-407) may include an effective area and an ineffective area. The effective area may be an area through which light incident on each of the lenses passes. In other words, the effective area may be defined as an effective area or effective diameter through which the incident light is refracted to implement optical characteristics. The ineffective area may be arranged around the periphery of the effective area. The ineffective area may be an area through which effective light is not incident from a plurality of lenses. In other words, the ineffective area may be an area unrelated to the optical characteristics. In addition, an end of the ineffective area may be an area fixed to a lens barrel or the like that accommodates the lens.

[0097]

[0098] Within the optical system (1000, 1100, 1200, 1300), the TTL (Total top length) may be more than 2 times, for example, more than 2 times and less than 5 times, than Imgh. The TTL (Total track length) is the distance from the center of the object-side surface of the first lens to the top surface of the image sensor (600) on the optical axis (OA). Imgh is the distance from the optical axis (OA) to the diagonal end of the image sensor (600) or the maximum diagonal length. Within the optical system (1000, 1100, 1200, 1300), the effective focal length (EFL) is 3 mm or more and 6 mm or less, and the horizontal field of view (FOV_H) is provided to be more than 75 degrees and less than 130 degrees, so that it can be provided as a standard optical system in a vehicle camera module. For example, the optical system and the camera module according to the embodiment can be applied to a camera for an ADAS (Advanced Driving Assistance System) installed inside or outside a vehicle.

[0099] The optical system (1000, 1100, 1200, 1300) can have a TTL / Imgh condition of 2 or more and 5 or less. By setting the TTL / Imgh value to 2 or more and 5 or less in the optical system (1000, 1100, 1200, 1300), a vehicle lens optical system can be provided. Accordingly, the optical system (1000, 1100, 1200, 1300) can provide an image without exaggeration or distortion in the formed image.

[0100]

[0101] The effective diameter of at least one plastic lens within the optical system (1000, 1100, 1200, 1300) may be smaller than the length of the image sensor (600). The effective diameter is the diameter or length of the effective area where light is incident. The length of the image sensor (600) is the maximum length of the diagonal in the direction orthogonal to the optical axis (OA). The number of lenses having an effective diameter larger than the length of the image sensor (600) within the optical system (1000, 1100, 1200, 1300) may be 50% or more or 60% or more, and the number of lenses having an effective diameter smaller than the length of the image sensor (600) may be less than 50% or less than 40%.

[0102] The lens unit (100, 200, 300, 400) may be a mixture of glass lenses and plastic lenses. The number of plastic lenses may be 60% or more of the total number of lenses, and may range from 70% to 80%. Accordingly, if more plastic lenses are placed within the camera module, the weight of the camera module can be reduced, and the plastic material makes it easy to polish and process, resistant to external impacts, competitively priced, and easy to secure materials. In addition, various aberrations can be corrected by the plastic lenses, thereby preventing deterioration of optical performance.

[0103] The embodiment of the invention can reduce the weight of the camera module, provide a lower manufacturing cost, suppress the deterioration of optical characteristics due to temperature change, and allow various types of plastic lenses to replace glass lenses by further mixing plastic lenses into the optical system (1000, 1100, 1200, 1300), and can facilitate polishing and processing of lens surfaces such as aspherical or free-form surfaces.

[0104]

[0105] The effective diameter of the lens closest to the object side within the lens unit (100, 200, 300, 400) may be larger than the effective diameter of the lens closest to the image sensor (600). Accordingly, the brightness of the optical system can be controlled. The effective diameter may be the average effective diameter of the object side and the sensor side of each lens. By controlling the effective diameter size of each lens, the optical system (1000, 1100, 1200, 1300) can control the incident light to compensate for the deterioration of optical characteristics due to resolution and temperature change, improve chromatic aberration control characteristics, and improve the vignetting characteristics of the optical system (1000, 1100, 1200, 1300).

[0106] The lens unit (100, 200, 300, 400) may include 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) aligned from the object side toward the sensor side along the optical axis.

[0107]

[0108] The lens unit (100, 200, 300, 400) may be arranged in a camera module having an inner barrel on one side or the entire inner surface of a lens barrel. The lens unit (100, 200, 300, 400) may be arranged in a camera module having a plurality of inner barrels around different lenses of the lens barrel. The lens unit (100, 200, 300, 400) may be arranged in a camera module having a first inner barrel in contact with the outer surface of at least one lens of the lens barrel and a second inner barrel in contact with the outer surface of at least one lens. The lens unit (100, 200, 300, 400) may be arranged in a camera module having a plurality of inner barrels each of which is arranged between the outer surface of at least one or two or more lenses and the lens barrel. The lens unit (100, 200, 300, 400) may be arranged in a camera module in which the plurality of inner barrels have a material different from a material of the lens barrel.

[0109] Among the lenses constituting the lens unit (100, 200, 300, 400), at least some of the lenses made of glass may be placed in the lens barrel, and at least some of the lenses made of plastic may be placed in the inner barrel placed within the lens barrel. Through this, the optical system (1000, 1100, 1200, 1300) can maintain resolution according to temperature changes. The lens unit (100, 200, 300, 400) may be placed in a camera module having different barrels to minimize decentering of lenses, such as plastic lenses, that expand according to temperature changes. The lens barrel in which the lens unit (100, 200, 300, 400) is placed has a plurality of inner barrels within the lens barrel, thereby maintaining the resolution of the optical system according to temperature changes and suppressing deformation of the lenses. Therefore, the effective diameter of at least some of the glass material lenses included in the lens unit (100, 200, 300, 400) may be smaller than the effective diameter of at least some of the plastic material lenses.

[0110]

[0111] When the average effective diameter of the lenses made of plastic is PLca_Aver and the average effective diameter of the lenses made of glass is GLca_Aver, the condition of PLca_Aver < GLca_Aver can be satisfied. In addition, the condition of 1 < GLca_Aver / PLca_Aver < 1.5 can be satisfied. In addition, the relationship between the diagonal length of the image sensor (600) and the average effective diameter (PLca_Aver) of the plastic lens can satisfy the condition of 0.5 < PLca_Aver / Imgh < 1. In addition, the relationship between the average effective diameter of the glass material and the length of the image sensor (600) can satisfy the condition of 0.5 < GLca_Aver / Imgh < 1. The difference between the maximum length of the image sensor (600) and the effective diameter of the lenses made of plastic material can be arranged so as not to be large. Accordingly, by placing a plastic lens with a small effective diameter adjacent to the image sensor (600), the plastic lenses can disperse color from the center to the periphery of the image sensor (600).

[0112]

[0113] The average effective diameter of the glass materials may be 7 mm or more, for example, in the range of 7 mm to 9 mm. The average effective diameter of the plastic material may be 6 mm or more, for example, in the range of 6 mm to 7 mm. The lens having the minimum effective diameter may be made of plastic, and the lens having the maximum effective diameter may be made of glass. Within the lens unit (100, 200, 300, 400), the minimum effective diameter may be in the range of 5 mm to 6 mm, and the maximum effective diameter may be in the range of 8 mm to 10 mm. The plastic lens is designed to have a smaller effective diameter than the glass lens, and is arranged so as not to touch the lens barrel, thereby minimizing changes in optical performance due to temperature changes. In addition, the optical system (1000, 1100, 1200, 1300) can improve the resolution and chromatic aberration control characteristics by controlling the incident light, and can improve the vignetting characteristics of the optical system (1000, 1100, 1200, 1300).

[0114]

[0115] The optical system (1000, 1100, 1200, 1300) or camera module may include an image sensor (600). The image sensor (600) can detect light and convert it into an electrical signal. The image sensor (600) can detect light that has sequentially passed through the lens units (100, 200, 300, 400). The image sensor (600) may include an element capable of detecting incident light, such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). Here, the number of lenses having an effective diameter smaller than the length of the image sensor (600) may be 5 to 7.

[0116]

[0117] The optical system (1000, 1100, 1200, 1300) or camera module may include a filter (700). The filter (700) may be positioned between the last lens and the image sensor (600). The filter (700) may be positioned between the lens closest to the sensor side among the lenses of the lens unit (100, 200, 300, 400) and the image sensor (600). For example, the filter (700) may be positioned between the nth lens and the image sensor (600).

[0118] The cover glass is placed between the filter (700) and the image sensor (600), and protects the upper portion of the image sensor (600) and can prevent a decrease in the reliability of the image sensor (600). The cover glass can be removed. The cover glass may be a protective glass.

[0119] The filter (700) may include an infrared filter or an infrared cut-off filter (IR cut-off). The filter (700) may allow light of a set wavelength band to pass through and filter out light of a different wavelength band. When the filter (700) includes an infrared filter, it may block radiant heat emitted from external light from being transmitted to the image sensor (600). In addition, the filter (700) may transmit visible light and reflect infrared light.

[0120] The optical system (1000, 1100, 1200, 1300) according to the embodiment may include an aperture (Stop). The aperture can control the amount of light incident on the optical system (1000, 1100, 1200, 1300). In the lenses arranged between the object and the aperture, the effective diameter of the lens surface tends to increase from the object side to the aperture. In the lens surfaces arranged between the aperture and the sensor, the effective diameter of the lens surfaces tends to decrease from the aperture to the sensor side. The tendency for the effective diameter of the lens surfaces to increase or decrease does not only mean the case where the effective diameter of the lens surfaces increases or decreases. For example, it also includes the case where the effective diameter of the lens surfaces increases and then decreases from the aperture to the sensor side.

[0121]

[0122] In the optical systems (1000, 1100, 1200, 1300) of the first to fourth embodiments, the sum of the refractive indices of the lenses of the lens units (100, 200, 300, 400) may be 10 or more, for example, in the range of 10 to 12, and the average of the refractive indices may be 1.58 to 1.7. The sum of the Abbe numbers of each of the lenses may be 250 or more, for example, in the range of 260 to 310, and the average of the Abbe numbers may be 50 or less, for example, in the range of 35 to 47. The sum of the central thicknesses of the entire lenses may be 10 mm or more, for example, in the range of 12 mm to 15 mm, and the average of the central thicknesses may be in the range of 1.5 mm to 2 mm. The sum of the central spacings between the lenses on the optical axis (OA) may be 5 mm or more, for example, in the range of 5 mm to 6 mm, and may be smaller than the sum of the central thicknesses of the lenses. Additionally, the average value of the effective diameter of each lens surface (S1-S14) of the lens section (100, 200, 300, 400) can be provided in the range of 7 mm or more, for example, 7 mm to 8 mm.

[0123]

[0124] In the optical system according to the first to fourth embodiments of the invention, the angle of view (diagonal) may be 100 degrees or less, for example, in the range of 85 to 95 degrees. The F number of the optical system or the camera module may be 2 or less, for example, in the range of 1.5 to 1.8. In the optical system according to the embodiment of the invention, the maximum angle of view (diagonal) may be 140 degrees or less, for example, in the range of 85 to 135 degrees. The vehicle optical system may have a horizontal field of view (FOV_H) in the Y-axis direction that may be greater than 75 degrees and less than 125 degrees, for example, in the range of 78 to 122 degrees. In addition, the vertical field of view is provided at an angle smaller than the horizontal field of view, and may be 70 degrees or less, for example, in the range of 43 to 68 degrees. The horizontal field of view (FOV_H) is an angle of view based on the horizontal length of the sensor. Accordingly, it is possible to suppress changes in the focus position due to temperature changes, and provide a vehicle camera in which various aberrations are well corrected.

[0125] Because the optical systems used in vehicle cameras typically monitor road conditions, they can be designed based on the horizontal field of view, rather than the entire field of view. The optical system according to this embodiment is designed with a certain margin based on the inscribed circle of the image sensor. This ensures guaranteed optical performance within the range that satisfies the horizontal field of view (FOV_H).

[0126]

[0127] To more effectively prevent scratches caused by foreign substances or objects placed inside a vehicle, a glass lens may be used as the first lens (101, 201, 301, 401), and the object-side surface of the first lens (101, 201, 301, 401) may have a gently curved shape so as not to come into contact with external structures. This minimizes the occurrence of scratches due to contact with external structures.

[0128] The optical system (1000, 1100, 1200, 1300) according to the embodiment may further include a reflective member for changing the path of light. The reflective member may be implemented as a prism that reflects incident light of the optical system (1000, 1100, 1200, 1300) toward the lenses. Hereinafter, the optical system according to the embodiment will be described in detail.

[0129]

[0130] An optical system according to a first embodiment of the invention will be described.

[0131] FIG. 1 is a side cross-sectional view of an optical system according to a first embodiment and a camera module having the same, FIG. 2 is a table showing aspherical coefficients of lenses in the optical system of FIG. 1, FIG. 3 is a table showing Sag values ​​of lens surfaces of first to seventh lenses in the optical system of FIG. 1, FIG. 4 is a graph showing data on diffraction MTF (Modulation Transfer Function) at room temperature of the optical system of FIG. 1, FIG. 5 is a graph showing data on diffraction MTF at low temperature of the optical system of FIG. 1, FIG. 6 is a graph showing data on diffraction MTF at high temperature of the optical system of FIG. 1, and FIG. 7 is a graph showing data on aberration characteristics of the optical system of FIG. 1 at room temperature.

[0132] Referring to FIG. 1, the optical system (1000) includes a lens unit (100), and the lens unit (100) may include a first lens (101) to a seventh lens (107). The first to seventh lenses (101 to 107) may be sequentially arranged along the optical axis (OA) of the optical system (1000). Light corresponding to information about an object may pass through the first lens (101) to the seventh lens (107) and a filter (500) and be incident on an image sensor (600).

[0133] 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 negative (-) refractive power on 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 radius of curvature due to temperature changes in the surrounding environment, and can protect the incident side surface of the optical system (1000).

[0134] The first surface (S1) on the object side of the first lens (101) with respect to the optical axis may be convex, and the second surface (S2) on the sensor side may be concave. The first lens (101) may have a concave meniscus shape toward the sensor side. The first lens (101) may have a convex meniscus shape toward the object side. The first lens (101) is made of glass and may have a spherical surface.

[0135] The refractive index (n1) of the first lens (101) can satisfy the condition of n1>1.5 or n1>1.51. If the refractive index (n1) of the first lens (101) satisfies the condition, the radius of curvature of the first and second lenses (101, 102) can be increased, and lens manufacturing can be facilitated. If the refractive index (n1) of the first lens (101) is smaller than the condition, the lens surface must be formed to be sharply concave or convex in order to increase the refractive power of the first and second lenses (101, 102). In this case, lens manufacturing is not easy, the lens defect rate increases, and it may cause a decrease in yield.

[0136]

[0137] 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 negative (-) refractive power in 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.

[0138] The third surface (S3) on the object side of the second lens (102) with respect to the optical axis (OA) may be concave, and the fourth surface (S4) on the sensor side may be convex. The second lens (102) may have a meniscus shape that is convex toward the sensor side. The second lens (102) may have a meniscus shape that is concave toward 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 aspherical coefficients of the third and fourth surfaces (S3, S4) may be provided as S1 and S2 of L2 in FIG. 2.

[0139] Additionally, due to the refractive characteristics of the first lens (101), the first lens (101) can be further separated from the second lens (102). That is, the center spacing between the first and second lenses (101, 102) can be the largest within the lens unit.

[0140] The third surface (S3) of the second lens (102) may be provided without a critical point from the optical axis (OA) to the end of the effective area. The fourth surface (S4) of the second lens (102) may have a critical point from the optical axis (OA) to the end of the effective area. When the fourth surface (S4) has a critical point, it may be located in a range of 35% to 45%, preferably 38% to 42%, of the effective radius (r42) from the optical axis (OA). The critical point of the fourth surface (S4) may be located in a range of 1 mm to 1.8 mm, preferably 1.2 mm to 1.6 mm from the optical axis (OA).

[0141] The critical point of the fourth surface (S4) is a point where the sign of the slope value with respect to the optical axis (OA) and the direction perpendicular to the optical axis (OA) changes from positive (+) to negative (-) or from negative (-) to positive (+), and may mean a point where the slope value is 0. In addition, the critical point of the fourth surface (S4) may be a point where the slope value of the tangent line passing through the lens surface increases and then decreases, or a point where the slope value decreases and then increases.

[0142]

[0143] 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.

[0144] The object-side fifth surface (S5) of the third lens (103) with respect to the optical axis is convex, and the sensor-side sixth surface (S6) may also be convex. The third lens (103) may have a convex shape on both sides. The third lens (103) may be made of glass and may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0145] The aperture (Stop) may be arranged around the sensor-side sixth surface (S6) of the third lens (103). The aperture (Stop) may be arranged around the object-side seventh surface (S7) of the fourth lens (104). The aperture can reduce the TTL within the field of view range, enabling miniaturization of the optical system. Accordingly, a decrease in the yield by weight of the optical system can be prevented, and production efficiency can be improved. In addition, the optical system can be miniaturized by reducing the TTL at a horizontal field of view (FOV_H) of 75 degrees to 85 degrees.

[0146]

[0147] The fourth lens (104) may be arranged fourth from the object side. The fourth lens (104) may be arranged fourth from the sensor side. The fourth lens (104) may be arranged between the third lens (103) and the fifth lens (105). The fourth lens (104) may have positive (+) or negative (-) refractive power on the optical axis (OA). The fourth lens (104) may have positive (+) refractive power. The fourth lens (104) may have positive (+) refractive power that is the same as the refractive power of the fifth lens (105). The fourth lens (104) may include a plastic or glass material. For example, the fourth lens (104) may be provided with a plastic material.

[0148] The seventh surface (S7) on the object side of the fourth lens (104) with respect to the optical axis may be concave, and the eighth surface (S8) on the sensor side may be convex. The fourth lens (104) may have a meniscus shape in which the sensor side is convex. The fourth lens (104) may have a meniscus shape in which the object side is concave. The fourth lens (104) is made of a plastic material and may have an aspherical surface. At least one or both of the seventh surface (S7) and the eighth surface (S8) may be aspherical. The aspherical coefficients of the seventh and eighth surfaces (S7, S8) may be provided as S1 and S2 of L4 in FIG. 2. The seventh surface (S7) and the eighth surface (S8) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0149]

[0150] The fifth lens (105) may be arranged fifth from the object side. The fifth lens (105) may be arranged 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 on the optical axis (OA). The fifth lens (105) may have positive (+) refractive power. The fifth lens (105) may have positive (+) refractive power that is the same as the refractive power of the fourth lens (104). The fifth lens (105) may include a plastic or glass material. For example, the fifth lens (105) may be provided with a plastic material. The fifth lens (105) may be provided with the same material as the sixth lens (106).

[0151] With respect to the optical axis (OA), the ninth surface (S9) on the object side of the fifth lens (105) may be convex, and the tenth surface (S10) on the sensor side may also be convex. The fifth lens (105) may have a shape in which both sides are convex with respect to the optical axis (OA). The fifth lens (105) may be made of a plastic material and may have an aspherical surface. At least one of the ninth surface (S9) and the tenth surface (S10) may be an aspherical surface. The aspherical coefficients of the ninth and tenth surfaces (S9, S10) may be provided as S1 and S2 of L5 in FIG. 2. At least one of the ninth and tenth surfaces (S9, S10) of the fifth lens (105) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0152]

[0153] The sixth lens (106) may be arranged as the sixth lens from the object side. The sixth lens (106) may be arranged as the second lens from the sensor side. The sixth lens (106) may be arranged between the fifth lens (105) and the seventh lens (107). The sixth lens (106) may have positive (+) or negative (-) refractive power on the optical axis (OA). The sixth lens (106) may have negative (-) 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.

[0154] With respect to the optical axis (OA), the object-side eleventh surface (S11) of the sixth lens (106) may be concave, and the sensor-side twelfth surface (S12) may also be concave. The sixth lens (106) may have a concave shape on both sides with respect to the optical axis (OA). At least one or both of the eleventh surface (S11) and the twelfth surface (S12) may be aspherical. The aspherical coefficients of the eleventh and twelfth surfaces (S11, S12) may be provided as S1 and S2 of L6 in FIG. 2. At least one of the eleventh surface (S11) and the twelfth surface (S12) of the sixth lens (106) may be provided without at least one critical point from the optical axis (OA) to the end of the effective area.

[0155]

[0156] The seventh lens (107) may be arranged closest to the sensor side. The seventh lens (107) may be arranged farthest from the object side. The seventh lens (107) may have positive (+) or negative (-) refractive power on the optical axis (OA). The seventh lens (107) may have positive (+) refractive power. The seventh lens (107) may include a plastic or glass material. For example, the seventh lens (107) may be made of a plastic material.

[0157] The object-side 13th surface (S13) of the seventh lens (107) on the optical axis may be convex, and the sensor-side 14th surface (S14) may also be convex. The seventh lens (107) may have a convex shape on both sides. At least one of the 13th surface (S13) and the 14th surface (S14) may be aspherical. For example, both the 13th surface (S13) and the 14th surface (S14) may be aspherical. The aspherical coefficients of the 13th and 14th surfaces (S13, S14) may be provided as S1 and S2 of L7 in FIG. 2.

[0158] The 13th surface (S13) of the seventh lens (107) may be provided without a critical point from the optical axis (OA) to the end of the effective area. The 14th surface (S14) of the seventh lens (107) may have a critical point from the optical axis (OA) to the end of the effective area. When the 14th surface (S14) has a critical point, it may be located in a range of 60% to 70%, preferably in a range of 62% to 68%, of the effective radius (r72) from the optical axis (OA). The critical point of the 14th surface (S14) may be located in a range of 2.3 mm to 3 mm, preferably in a range of 2.5 mm to 2.8 mm from the optical axis (OA).

[0159] The critical point of the 14th surface (S14) is a point where the sign of the slope value with respect to the optical axis (OA) and the direction perpendicular to the optical axis (OA) changes from positive (+) to negative (-) or from negative (-) to positive (+), and may mean a point where the slope value is 0. In addition, the critical point of the 14th surface (S14) may be a point where the slope value of the tangent line passing through the lens surface increases and then decreases, or a point where the slope value decreases and then increases.

[0160] The seventh lens (107) may be a plastic lens closest to the image sensor (600). In addition, by arranging two or more plastic lenses adjacent to the image sensor (600), aberrations such as spherical aberration and chromatic aberration can be improved by the lens surface having an aspherical surface, and the influence on the resolution can be controlled. In addition, by arranging the plastic lens as the lens adjacent to the image sensor (600), it can be insensitive to assembly tolerances compared to a glass lens. In other words, being insensitive to assembly tolerances means that even if the assembly is slightly different from the design during assembly, the optical performance may not be significantly affected. In addition, by providing the two lenses (106, 107) adjacent to the image sensor (600) as plastic, the optical performance can be improved by the lens surface having an aspherical surface, and for example, aberration characteristics can be improved and resolution deterioration can be prevented.

[0161]

[0162] LensSurfaceRadiusThicknessndvdSemiApertureFocal length1S187.5221.2791.52645.152-8.357 S24.1113.1473.430 2S3-5.7030.9001.63223.250-13.044 S4-19.3380.1003.415 3S5123.3211.91343.5676.300S6-9.5381.0733.675 StopInfinity0.4793.104 4S7-7.2431.9721.54563.10141.963 S8-6.0030.2933.100 5S98.3282.7121.54553.3439.337 S10-11.1970.0713.250 6S11-8.0640.9001.63233.204-5.811 S127.0860.4813.317 7S135.6602.7521.54564.0009.645 S14-50.9050.5954.090 FilterS15Infinity0.5001.52643.872Infinity S16Infinity0.1003.925 Image Infinity-0.1364.626

[0163]

[0164] Table 1 shows the surface number (Surface), radius of curvature (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 (Fcoal length) of the lens according to the first embodiment of the present invention. At this time, the unit of the radius of curvature and thickness or distance may be mm.

[0165]

[0166] Item ValueItem ValueF5.711ET12.9676ΣIndex11.291ET21.7597ΣAbbe309.549ET32.0621ΣCT14. 3367ET41.7473ΣCG5.164ET51.3599CA_max11.517ET62.3762CA_min5.639ET71.632 1CA_Aver7.359F-number1.6638CT_max3.321FOV_D91.680CT_min0.500FOV_V45.3CT_Aver1.792FOV_H80.0EPD3.433ImgH9.252BFL1.059SD10.26TD20.07TTL20.5382

[0167]

[0168] Table 2 shows the items of the mathematical formulas described above in the optical system (1000) of the embodiment, including the total track length (TTL) (mm), back focal length (BFL), effective focal length (F) (mm), ImgH (mm), effective diameter (CA) (mm), thickness (mm), TTL (mm), the optical axis distance from the first surface (S1) to the fourteenth surface (S14) TD (mm), the optical axis distance from the stop (Stop) to the fourteenth surface (S14) SD (mm), the sum of refractive indices, the sum of Abbe numbers, the sum of thicknesses (mm), the sum of spacings between adjacent lenses, the effective diameter characteristics, the diagonal angle of view (FOV_D) (Degree), the vertical angle of view (FOV_V) (Degree), the horizontal angle of view (FOV_H) (Degree), the edge thickness (ET), the F number, etc. of the optical system (1000).

[0169]

[0170] The center thicknesses of the first to seventh lenses (101 to 107) are represented by CT1 to CT7, the edge thicknesses at the ends of the effective areas of each lens are represented by ET1 to ET7, the center gap between two adjacent lenses is represented by CG1 to CG6, and the edge gaps between the edges of each lens are represented by EG1 to EG6. The BFL (Back focal length) is the optical axis distance from the image sensor (600) 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 upper surface of the image sensor (600).

[0171] As shown in FIG. 2, among the lenses of the lens unit (100) in the first embodiment, the lens surfaces of the second, fourth, fifth, sixth, and seventh lenses (102, 104, 105, 106, and 107) may include aspherical surfaces having a 30th-order aspherical coefficient. For example, the second, fourth, fifth, sixth, and seventh lenses (102, 104, 105, 106, and 107) may include lens surfaces having a 30th-order aspherical coefficient. As described above, since the aspherical surface having a 30th-order aspherical coefficient (a value other than "0") can significantly change the aspherical shape of the periphery, the optical performance of the periphery of the field of view (FOV) can be well corrected.

[0172] When comparing the absolute values ​​of the curvature radii of each lens, the curvature radii of the first surface (S1) of the first lens (101) on the optical axis (OA) may be the largest among the lenses, and the curvature radii of the second surface (S2) of the first lens (101) may be the smallest among the lenses. The difference between the maximum curvature radii and the minimum curvature radii may be 21 times or more, for example, 20 to 22 times. The curvature radii of the sensor-side surface of the glass-material lens arranged on the object-side surface of the plastic-material lens may be the smallest among the lenses. The curvature radii of the sensor-side surface of the first lens (101) arranged on the object-side surface of the second lens (102) may be the smallest among the lenses.

[0173] Since the effective diameter of a plastic lens is smaller than that of a glass lens, the lens placed on the object side of the plastic lens can have a strong refractive power to refract light through the plastic lens. In addition, the radius of curvature of the lens surface can be small to increase the refractive power.

[0174] Among the lenses, there may be 8 or more and 10 or fewer surfaces with an absolute value of curvature radius of 10 mm or less on the object side and sensor side. The radius of curvature of the sensor side (second surface (S2)) of the first lens (101), the object side (third surface (S3)) of the second lens (102), the sensor side (sixth surface (S6)) of the third lens (103), the object side (seventh surface (S7)) of the fourth lens (104), the sensor side (eighth surface (S8)) of the fourth lens (104), the object side (ninth surface (S9)) of the fifth lens (105), the object side (eleventh surface (S11)) of the sixth lens (106), the sensor side (twelfth surface (S12)) of the sixth lens (106), and the object side (thirteenth surface (S13)) of the seventh lens (107) may have an absolute value of 10 mm or less. Among the lenses, there may be two or more and four or fewer surfaces with an absolute value of curvature radius of 10 mm or more and 20 mm or less on the object side and the sensor side.

[0175] The absolute values ​​of the curvature radii of the sensor side (fourth surface (S4)) of the second lens (102), the object side (fifth surface (S5)) of the third lens (103), and the sensor side (tenth surface (S10)) of the fifth lens (105) may be 10 mm or more and 20 mm or less. Among the lenses, the number of surfaces having an absolute value of a curvature radius of 50 mm or more among the object side and the sensor side may be one or more and three or less. The absolute values ​​of the curvature radii of the object side (first surface (S1)) of the first lens (101) and the sensor side (fourteenth surface (S14)) of the seventh lens (107) may be 50 mm or more.

[0176] In temperature-compensated designs that require maintaining resolution across temperatures ranging from -40 to 100 degrees Celsius, a larger radius of curvature can be advantageous. Aluminum lens barrels can be used for temperature compensation. Aluminum barrels have large manufacturing tolerances, which can significantly misalign the optical axes of individual lenses during assembly. Therefore, a larger radius of curvature can be used to reduce sensitivity to manufacturing tolerances.

[0177] The shape of the first lens (101) having a spherical shape can be designed to be gentle. If the spherical surface is positioned at the frontmost position in the optical system (1000), the performance of the lens is improved, but the assemblability may be reduced. To improve the assemblability, the shape of the first lens (101) must be designed to be gentle. In order to minimize the influence on the lens placed on the sensor side when assembling the lens in the barrel, the first lens (101) can be designed to have almost no curvature.

[0178] The absolute value of the curvature radius of the first surface (S1) of the first lens (101) may be greater than the absolute value of the curvature radius of the second surface (S2). The absolute value of the curvature radius of the third surface (S3) of the second lens (102) may be less than the absolute value of the curvature radius of the fourth surface (S4). The absolute value of the curvature radius of the fifth surface (S5) of the third lens (103) may be greater than the absolute value of the curvature radius of the sixth surface (S6). The absolute value of the curvature radius of the seventh surface (S7) of the fourth lens (104) may be greater than the absolute value of the curvature radius of the eighth surface (S8). The absolute value of the curvature radius of the ninth surface (S9) of the fifth lens (105) may be less than the absolute value of the curvature radius 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). The absolute value of the radius of curvature of the thirteenth surface (S13) of the seventh lens (107) may be less than the absolute value of the radius of curvature of the fourteenth surface (S14).

[0179] The ratio of the radius of curvature of each lens can satisfy the following conditions.

[0180] Condition 1: 20 < |L1R1 / L1R2| < 23

[0181] Condition 2: 0.1 < |L2R1 / L2R2| < 0.4

[0182] Condition 3: 1 < |L3R1 / L3R2| < 1.5

[0183] Condition 4: 1 < |L4R1 / L4R2| < 1.5

[0184] Condition 5: 0.5 < |L5R1 / L5R2| < 1

[0185] Condition 6: 1 < |L6R1 / L6R2| < 1.5

[0186] Condition 7: 0.1 < |L7R1 / L7R2| < 0.3

[0187]

[0188] When describing the central thickness of the lenses based on the optical axis, the central thickness (CT3) of the third lens (103) is the largest among the lenses, and the central thickness (CT2) of the second lens (102) and the central thickness (CT6) of the sixth lens are the smallest among the lenses. The difference between the maximum and minimum central thicknesses among the lenses may be in the range of 2.0 mm or more and 2.5 mm or less.

[0189] The central thickness of each lens may satisfy any one of the conditions below.

[0190] Condition 1: CT3, CT4, CT5, CT7 > CT1 > CT2, CT6

[0191] Condition 2: CT1, CT3, CT4, CT5, CT7 > CT2 = CT6

[0192] Condition 3: CT3 > CT1, CT2, CT4, CT5, CT6, CT7

[0193] Condition 4: CT3, CT5, CT7 > CT4 > CT1, CT2, CT6

[0194] Condition 5: CT3, CT7 > CT5 > CT1, CT2, CT4, CT6

[0195] Condition 6: CT3 > CT7 > CT1, CT2, CT4, CT5, CT6

[0196]

[0197] When describing the center spacing (CG) between the lenses, the center spacing (CG1) between the first lens (101) and the second lens (102) may be the maximum, and the center spacing (CG5) between the fifth and sixth lenses (105, 106) may be the minimum. The difference between the maximum center spacing and the minimum center spacing among the spaced lens spacings may be 3.0 mm or more, for example, in the range of 3.0 mm to 3.2 mm.

[0198] The center spacing between each lens can satisfy the conditions below.

[0199] Condition 1: CG1 > CG2, CG3, CG4, CG5, CG6

[0200] Condition 2: CG1, CG3, CG4, CG6 > CG2 > CG5

[0201] Condition 3: CG1 > CG3 > CG2, CG4, CG5, CG6

[0202] Condition 4: CG1, CG3, CG6 > CG4 > CG2, CG5

[0203] Condition 5: CG1, CG2, CG3, CG4, CG6 > CG5

[0204] Condition 6: CG1, CG3 > CG6 > CG2, CG4, CG5

[0205]

[0206] Regarding the effective diameter, the lens having the maximum effective diameter may be placed between the first lens (101) closest to the object and the seventh lens (107) closest to the image sensor (600). The lens having the maximum effective diameter may be a glass lens. The lens having the maximum effective diameter may be the first lens (101). Here, the effective diameter is the average of the effective diameters on the object-side surface and the sensor-side surface of each lens. The lens surface having the maximum effective diameter may be the first surface (S1) of the first lens (101).

[0207] The lens having the minimum effective diameter may be any one of the plastic material lenses, and for example, the effective diameter of the fourth lens (105) may be the minimum within the lens unit (100). The lens surface having the minimum effective diameter may be the eighth surface (S8) of the fourth lens (104). The effective diameter of the plastic material lens may be smaller than the effective diameter of the glass material lens.

[0208] The effective diameter of each lens can satisfy any one of the conditions below.

[0209] Condition 1: CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0210] Condition 2: CA_L1, CA_L3, CA_L7 > CA_L2 > CA_L4, CA_L5, CA_L6,

[0211] Condition 3: CA_L1, CA_L7 > CA_L3 > CA_L2, CA_L4, CA_L5, CA_L6

[0212] Condition 4: CA_L1, CA_L2, CA_L3, CA_L5, CA_L6, CA_L7 > CA_L4

[0213] Condition 5: CA_L1, CA_L2, CA_L3, CA_L7 > CA_L5 > CA_L4, CA_L6

[0214] Condition 6: CA_L1, CA_L2, CA_L3, CA_L5, CA_L7 > CA_L6 > CA_L4

[0215] Condition 7: CA_L1 > CA_L7 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6

[0216]

[0217] In terms of refractive index, the refractive index of the third lens (103) may be the largest among the lenses and may be greater than 1.8, for example, greater than 1.9. The first lens (101) may have the smallest refractive index among the lenses. For example, the refractive index of the first lens (101) may be the smallest among the lenses and may be less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index may be 0.3 or more. The glass material closest to the stop is provided as a high refractive index lens, and the lens adjacent to the glass material lens and the lens adjacent to the image sensor (600) are provided as low refractive index lenses made of plastic material, thereby increasing the incidence efficiency and adjusting the refractive power between the glass material and the plastic material lenses to guide light to the image sensor (600).

[0218] The refractive index of each lens can satisfy any of the conditions below.

[0219] Condition 1: n2, n3, n4, n5, n6, n7 > n1

[0220] Condition 2: n3 > n2 = n6 > n1, n4, n5, n7

[0221] Condition 3: n3 > n1, n2, n4, n5, n6, n7

[0222] Condition 4: n2, n3, n6 > n4 = n5 = n7 > n1

[0223]

[0224] Comparing the Abbe numbers, the Abbe number of the first lens (101) is the largest among the lenses and may be 60 or more. The Abbe number of the second lens (102) is the smallest among the lenses and may be 25 or less. The difference between the maximum Abbe number and the minimum Abbe number may be 40 or more. By providing the Abbe number of the first lens (101) as the largest and the Abbe number of the second lens (102) as the smallest, the color dispersion of light traveling between the lenses made of glass can be controlled, and the color dispersion between the lenses made of glass and plastic can be increased to guide it to the image sensor (600).

[0225] The Abbe number of each lens can satisfy any of the conditions below.

[0226] Condition 1: v1 > v2, v3, v4, v5, v6, v7

[0227] Condition 2: v1, v3, v4, v5, v6, v7 > v2

[0228] Condition 3: v1, v4, v5, v7 > v3 > v2, v6

[0229] Condition 4: v1 > v4 = v7 > v2, v3, v5, v6

[0230] Condition 5: v1, v4, v7 > v5 > v2, v3, v6

[0231] Condition 6: v1, v3, v4, v5, v7 > v6 > v2

[0232]

[0233] The focal lengths (F1, F2, F6) of the first, second, and sixth lenses (101, 102, and 106) may have negative (-) signs. The first, second, and sixth lenses (101, 102, and 106) may have negative (-) refractive power. The focal lengths (F3, F4, F5, F7) of the third, fourth, fifth, and seventh lenses (103, 104, 105, and 107) may have positive (+) signs. The third, fourth, fifth, and seventh lenses (103, 104, 105, and 107) may have positive (+) refractive power. The third, fourth, and fifth lenses (103, 104, and 105) having positive (+) refractive power may be arranged on the sensor side of the second lens (102) having negative (-) refractive power. Through this, light incident from the object side can move away from the optical axis direction and then gather again in the optical axis direction, thereby forming a stable optical path.

[0234] Additionally, the fifth lens (105) and the sixth lens (106), which are adjacently arranged lenses, can satisfy the following conditions.

[0235] Condition 1: Refractive index of lens with positive refractive power < refractive index of lens with negative refractive power

[0236] Condition 2: Dispersion of a lens with positive refractive power > Dispersion of a lens with negative refractive power

[0237] Here, among the plastic lenses, the fifth lens (105) has positive refractive power and the sixth lens (106) has negative refractive power, so that according to conditions 1 and 2, the refractive index of the fifth lens (105) is smaller than the refractive index of the sixth lens (106), and the dispersion value of the fifth lens (105) is larger than the dispersion value of the sixth lens (106). The chromatic aberration occurring in the plastic lens can be corrected by the plastic lens. In addition, since the fifth lens (105) and the sixth lens (106), which are plastic lenses arranged in succession, 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, the chromatic aberration occurring in the plastic lens can be compensated for by the plastic lens.

[0238] Optical systems suffer from chromatic aberration, and chromatic aberration is corrected by using cemented lenses or two lenses arranged in series. As the temperature changes from low to high, the lenses contract and expand repeatedly. Since the amount of change in lens characteristics due to temperature changes is the same for lenses made of the same material, 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, chromatic aberration occurring in a plastic lens is corrected by using the fifth lens (105) and the sixth lens (106).

[0239]

[0240] When comparing the focal lengths in absolute values, the focal length of the fourth lens (104) is the largest among the lenses, and may be 40 or more and 50 or less. Among the lenses, the fourth lens (104) made of plastic may have the largest focal length and the smallest refractive power. The focal length of the sixth lens (106) is the smallest among the lenses, and the absolute value of the focal length of the sixth lens (106) may be 5 or more and 10 or less. Among the lenses, the sixth lens (106) made of plastic may have the smallest focal length and the largest refractive power.

[0241] Among the lenses, the lens having the minimum focal length may be the sixth lens (106). The difference between the maximum focal length and the minimum focal length may be 30 or more or 40 or more. Accordingly, the optical system may have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. in the set field of view range, and may have good optical performance in the periphery of the field of view.

[0242] The absolute value of the focal length of each lens can satisfy any of the conditions below.

[0243] Condition 1: |f2|, |f4|, |f5|, |f7| > |f1| > |f3|, |f6|

[0244] Condition 2: |f4| > |f2| > |f1|, |f3|, |f5|, |f6|, |f7|

[0245] Condition 3: |f1|, |f2|, |f4|, |f5|, |f7| > |f3| > |f6|

[0246] Condition 4: |f4| > |f1|, |f2|, |f3|, |f5|, |f6|, |f7|

[0247] Condition 5: |f2|, |f4|, |f7| > |f5| > |f1|, |f3|, |f6|

[0248] Condition 6: |f1|, |f2|, |f3|, |f4|, |f5|, |f7| > |f6|

[0249] Condition 7: |f2|, |f4| > |f7| > |f1|, |f3|, |f5|, |f6|

[0250]

[0251] Any one of the fifth to seventh lenses (105-107) made of a plastic material and arranged adjacent to the sensor side may have a different refractive power from the other two. For example, the fifth and seventh lenses (105, 107) may have positive (+) refractive power, and the sixth lens (106) may have negative (-) refractive power. The absolute value of the focal length of one lens having a different refractive power from the other two among the fifth to seventh lenses (105-107) may be smaller than the absolute values ​​of the focal lengths of the other two. The refractive power of one lens having a different refractive power from the other two among the fifth to seventh lenses (105-107) may be larger than the refractive powers of the other two. For example, the absolute value of the focal length of the sixth lens (106) having a negative (-) refractive power may be smaller than the absolute values ​​of the focal lengths of the fifth and seventh lenses (105, 107) having a positive (+) refractive power.

[0252] Since the plastic lens disposed adjacent to the image sensor (600) is sensitive to temperature changes, the composite refractive power of the plastic lens can be designed to be close to 0. In other words, the composite refractive power of the plastic lens disposed adjacent to the image sensor (600) can be reduced. Through this, the refractive power of the plastic lens, which is sensitive to temperature changes, can be offset within the plastic lens, thereby minimizing changes in the performance of the overall optical system, and minimizing the influence of the plastic lens on the optical performance of the overall optical system (1000).

[0253] The ratio of the absolute values ​​of the focal lengths of the glass lenses included in the optical system (1000) can satisfy a value of 1 or more and 1.5 or less. For example, the absolute value (|f1| / |f3|) of the ratio of the focal lengths of the first lens (101) and the third lens (103) made of glass can satisfy a value of 1.2 or more and 1.4 or less. In addition, the signs of the focal lengths of the first lens (101) and the third lens (103) made of glass can be different from each other. Through this, the overall refractive power of the optical system (1000) can be greatly affected by the glass lens that is strong against temperature changes.

[0254]

[0255] The thickness (T1) of the first lens (101) may be maximum at the edge and minimum at the center, and the maximum thickness is in the range of 2 to 2.5 times the minimum thickness. The thickness (T2) of the second lens (102) may be maximum at the edge and minimum at the center, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T3) of the third lens (103) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T4) of the fourth lens (104) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1 to 1.5 times the minimum thickness. The thickness (T5) of the fifth lens (105) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T6) of the sixth lens (106) may be minimum at the center and maximum at the edge, and the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T7) of the seventh lens (107) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness.

[0256] The thickness of each lens can satisfy any of the conditions below.

[0257] Condition 1: 0.3 < CT1 / ET1 < 0.5, 2 < ET1 / CT1 < 2.5

[0258] Condition 2: 0.3 < CT2 / ET2 < 0.7, 1.5 < ET2 / CT2 < 2

[0259] Condition 3: 1.5 < CT3 / ET3 < 2, 0.5 < ET3 / CT3 < 2

[0260] Condition 4: 1 < CT4 / ET4 < 1.5, 0.5 < ET4 / CT4 < 1

[0261] Condition 5: 1.5 < CT5 / ET5 < 2, 0.3 < ET5 / CT5 < 0.7

[0262] Condition 6: 0.1 < CT6 / ET6 < 0.5, 2.5 < ET6 / CT6 < 3

[0263] Condition 7: 1.5 < CT7 / ET7 < 2, 0.3 < ET7 / CT7 < 0.8

[0264] Condition 8: 0.8 < ΣCT / ΣET < 1, 1 < ΣET / ΣCT < 1.2

[0265]

[0266] Among the gaps (G1-G6) between the lenses, the first gap (G1) between the first and second lenses (101, 102) may have a minimum in the center and a maximum in the edge. The second gap (G2) between the second and third lenses (102, 103) may have a maximum in the edge and a minimum in the center. The third gap (G3) between the third and fourth lenses (103, 104) may have a maximum in the edge and a minimum in the center. The fifth gap (G5) between the fifth and sixth lenses (105, 106) may have a maximum in the center and a minimum in the edge. The sixth gap (G6) between the sixth and seventh lenses (106, 107) may have a maximum in the center and a minimum in the edge.

[0267]

[0268] FIGS. 4 to 6 are graphs showing the diffraction MTF (Modulation Transfer Function) at room temperature, low temperature, and high temperature in the optical system of FIG. 1, and are graphs showing the modulation ratio according to spatial frequency. As shown in FIGS. 4 to 6, in the first embodiment of the invention, the deviation of the MTF at low temperature or high temperature based on room temperature may be less than 10%, that is, 7% or less.

[0269] Table 3 shows changes in optical characteristics such as EFL and field of view (FOV_H) at room temperature, low temperature, and high temperature in the optical system according to the first embodiment. It can be seen that the change rate of the optical characteristics at low temperature is 5% or less, for example, 3% or less, based on room temperature, and it can be seen that the change rate of the optical characteristics at low temperature is 5% or less, for example, 3% or less, based on room temperature. In addition, Table 3 compares the MTF focus position shift in the optical system according to the first embodiment, and the MTF focus position shift at low and high temperatures can satisfy a range of 10 um or less based on room temperature, and can satisfy a range of 6 um or less, for example.

[0270]

[0271] Room temperature low temperature high temperature low temperature / Room temperature high temperature / Room temperature EFL(F) 5.71145.64645.790698.86 %101.38%FOV_H808080100%100%MTF focus position Shift1.1um-0.9um3.9um--

[0272]

[0273] Therefore, as shown in Table 3, it can be seen that the change in optical characteristics according to the temperature change from low temperature to high temperature, for example, the change rate of effective focal length (EFL) and the change rate of horizontal field of view (FOV_H), is 10% or less, that is, 5% or less, for example, in the range of 0 to 5%. This means that even if at least one or two or more plastic lenses are used, the design can enable temperature compensation for the plastic lenses, thereby preventing a decrease in the reliability of the optical characteristics.

[0274] The optical system of the first embodiment disclosed above can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only at the center of the field of view (FOV) but also at the periphery.

[0275]

[0276] An optical system according to a second embodiment of the invention will be described.

[0277] FIG. 8 is a side cross-sectional view of an optical system according to a second embodiment and a camera module having the same, FIG. 9 is a table showing aspherical coefficients of lenses in the optical system of FIG. 8, FIG. 10 is a table showing Sag values ​​of lens surfaces of first to seventh lenses in the optical system of FIG. 8, FIG. 11 is a graph showing data on diffraction MTF (Modulation Transfer Function) at room temperature of the optical system of FIG. 8, FIG. 12 is a graph showing data on diffraction MTF at low temperature of the optical system of FIG. 8, FIG. 13 is a graph showing data on diffraction MTF at high temperature of the optical system of FIG. 8, and FIG. 14 is a graph showing data on aberration characteristics at room temperature of the optical system of FIG. 8.

[0278] Referring to FIG. 8, the optical system (1100) includes a lens unit (200), and the lens unit (200) may include a first lens (201) to a seventh lens (207). The first to seventh lenses (201 to 207) may be sequentially arranged along the optical axis (OA) of the optical system (1100). Light corresponding to information about an object may pass through the first lens (201) to the seventh lens (207) and a filter (700) and be incident on the image sensor (600).

[0279] 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 negative (-) refractive power on the optical axis (OA). The first lens (201) may include a plastic material or a glass material, and may be made of glass, for example. The first lens (201) made of glass can reduce changes in the center position and radius of curvature due to temperature changes in the surrounding environment, and can protect the incident side surface of the optical system (1100).

[0280] The first surface (S1) on the object side of the first lens (201) is concave with respect to the optical axis, and the second surface (S2) on the sensor side may also be concave. The first lens (201) may have a concave shape on both sides. The first lens (201) is made of glass and may have a spherical surface.

[0281] The refractive index (n1) of the first lens (201) can satisfy the condition of n1>1.5 or n1>1.51. If the refractive index (n1) of the first lens (201) satisfies the condition, the radius of curvature of the first and second lenses (201, 202) can be increased, and lens manufacturing can be facilitated. If the refractive index (n1) of the first lens (201) is smaller than the condition, the lens surface must be formed to be sharply concave or convex in order to increase the refractive power of the first and second lenses (201, 202). In this case, lens manufacturing is not easy, the lens defect rate increases, and it may cause a decrease in yield.

[0282]

[0283] 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 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.

[0284] The object-side third surface (S3) of the second lens (202) is concave with respect to the optical axis (OA), and the sensor-side fourth surface (S4) may also be concave. The second lens (202) may have a concave shape on both sides. 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 aspherical coefficients of the third and fourth surfaces (S3, S4) may be provided as S1 and S2 of L2 in FIG. 9.

[0285] Additionally, due to the refractive characteristics of the first lens (201), the first lens (201) can be further separated from the second lens (202). That is, the center spacing between the first and second lenses (201, 202) can be the largest within the lens unit.

[0286] The third surface (S3) of the second lens (102) may be provided without a critical point from the optical axis (OA) to the end of the effective area. The fourth surface (S4) of the second lens (202) may have a critical point from the optical axis (OA) to the end of the effective area. When the fourth surface (S4) has a critical point, it may be located in a range of 35% to 45%, preferably 38% to 42%, of the effective radius (r42) from the optical axis (OA). The critical point of the fourth surface (S4) may be located in a range of 1 mm to 1.8 mm, preferably 1.2 mm to 1.6 mm from the optical axis (OA).

[0287] The critical point of the fourth surface (S4) is the point where the sign of the slope value with respect to the optical axis (OA) and the direction perpendicular to the optical axis (OA) changes from positive (+) to negative (-) or from negative (-) to positive (+), and may mean the point where the slope value is 0. In addition, the critical point of the fourth surface (S4) may be the point where the slope value of the tangent line passing through the lens surface increases and then decreases, or the point where the slope value decreases and then increases.

[0288]

[0289] The third lens (203) may be arranged third from the object side. The third lens (203) may be arranged fifth from the sensor side. The third lens (203) may be arranged between the second lens (202) and the fourth lens (204). The third lens (203) may have positive (+) refractive power on the optical axis (OA). The third lens (203) may include a plastic or glass material. For example, the third lens (203) may be provided as a glass material.

[0290] The object-side fifth surface (S5) of the third lens (203) with respect to the optical axis is convex, and the sensor-side sixth surface (S6) may also be convex. The third lens (203) may have a convex shape on both sides. The third lens (203) may be made of glass and may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0291] The aperture (Stop) may be arranged around the sensor-side sixth surface (S6) of the third lens (203). The aperture (Stop) may be arranged around the object-side seventh surface (S7) of the fourth lens (204). The aperture can reduce the TTL within the field of view range, enabling miniaturization of the optical system. Accordingly, a decrease in the yield by weight of the optical system can be prevented, and production efficiency can be improved. In addition, the optical system can be miniaturized by reducing the TTL within the horizontal field of view (FOV_H) of 75 degrees to 85 degrees.

[0292]

[0293] 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 have the same positive (+) refractive power as the refractive power of the fifth lens (205). The fourth lens (204) may include a plastic or glass material. For example, the fourth lens (204) may be provided with a plastic material. The fourth lens (204) may be provided with the same material as the fifth lens (205).

[0294] The seventh surface (S7) on the object side of the fourth lens (204) with respect to the optical axis may be concave, and the eighth surface (S8) on the sensor side may be convex. The fourth lens (204) may have a meniscus shape in which the sensor side is convex. The fourth lens (204) may have a meniscus shape in which the object side is concave. The fourth lens (204) is made of a plastic material and may have an aspherical surface. At least one or both of the seventh surface (S7) and the eighth surface (S8) may be aspherical. The aspherical coefficients of the seventh and eighth surfaces (S7, S8) may be provided as S1 and S2 of L4 in FIG. 9. The seventh surface (S7) and the eighth surface (S8) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0295]

[0296] The fifth lens (205) may be arranged as the fifth lens from the object side. The fifth lens (205) may be arranged as the third lens from the sensor side. The fifth lens (205) may be arranged between the fourth lens (204) and the sixth lens (206). The fifth lens (205) may have positive (+) or negative (-) refractive power on the optical axis (OA). The fifth lens (205) may have positive (+) refractive power. The fifth lens (205) may have the same positive (+) refractive power as the refractive power of the fourth lens (204). The fifth lens (205) may include a plastic or glass material. For example, the fifth lens (205) may be provided as a plastic material. The fifth lens (205) may be provided as the same material as the fourth lens (204).

[0297] With respect to the optical axis (OA), the ninth surface (S9) on the object side of the fifth lens (205) may be convex, and the tenth surface (S10) on the sensor side may also be convex. The fifth lens (205) may have a shape in which both sides are convex with respect to the optical axis (OA). The fifth lens (205) may be made of a plastic material and may have an aspherical surface. At least one of the ninth surface (S9) and the tenth surface (S10) may be an aspherical surface. The aspherical coefficients of the ninth and tenth surfaces (S9, S10) may be provided as S1 and S2 of L5 in FIG. 9. At least one or both of the ninth and tenth surfaces (S9, S10) of the fifth lens (205) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0298]

[0299] The sixth lens (206) may be arranged as the sixth lens from the object side. The sixth lens (206) may be arranged as the second lens from the sensor side. The sixth lens (206) may be arranged between the fifth lens (205) and the seventh lens (207). The sixth lens (206) may have positive (+) or negative (-) refractive power on the optical axis (OA). The sixth lens (206) may have negative (-) 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.

[0300] With respect to the optical axis (OA), the object-side eleventh surface (S11) of the sixth lens (206) may be concave, and the sensor-side twelfth surface (S12) may also be concave. The sixth lens (206) may have a concave shape on both sides with respect to the optical axis (OA). At least one or both of the eleventh surface (S11) and the twelfth surface (S12) may be aspherical. The aspherical coefficients of the eleventh and twelfth surfaces (S11, S12) may be provided as S1 and S2 of L6 in FIG. 9. At least one of the eleventh surface (S11) and the twelfth surface (S12) of the sixth lens (206) may be provided without at least one critical point from the optical axis (OA) to the end of the effective area.

[0301]

[0302] The seventh lens (207) may be arranged closest to the sensor side. The seventh lens (207) may be arranged farthest from the object side. The seventh lens (207) may have positive (+) or negative (-) refractive power on the optical axis (OA). The seventh lens (207) may have positive (+) refractive power. The seventh lens (207) may include a plastic or glass material. For example, the seventh lens (207) may be made of a plastic material.

[0303] The object-side 13th surface (S13) of the seventh lens (207) on the optical axis may be convex, and the sensor-side 14th surface (S14) may also be convex. The seventh lens (207) may have a convex shape on both sides. At least one of the 13th surface (S13) and the 14th surface (S14) may be aspherical. For example, both the 13th surface (S13) and the 14th surface (S14) may be aspherical. The aspherical coefficients of the 13th and 14th surfaces (S13, S14) may be provided as S1 and S2 of L7 in FIG. 9.

[0304] The 13th surface (S13) of the 7th lens (107) may be provided without a critical point from the optical axis (OA) to the end of the effective area. The 14th surface (S14) of the 7th lens (207) may have a critical point from the optical axis (OA) to the end of the effective area. When the 14th surface (S14) has a critical point, it may be located in a range of 60% to 70%, preferably in a range of 62% to 68%, of the effective radius (r72) from the optical axis (OA). The critical point of the 14th surface (S14) may be located in a range of 2.3 mm to 3 mm, preferably in a range of 2.5 mm to 2.8 mm from the optical axis (OA).

[0305] The critical point of the 14th surface (S14) is a point where the sign of the slope value with respect to the optical axis (OA) and the direction perpendicular to the optical axis (OA) changes from positive (+) to negative (-) or from negative (-) to positive (+), and may mean a point where the slope value is 0. In addition, the critical point of the 14th surface (S14) may be a point where the slope value of the tangent line passing through the lens surface increases and then decreases, or a point where the slope value decreases and then increases.

[0306] The seventh lens (207) may be a plastic lens closest to the image sensor (600). In addition, by arranging two or more plastic lenses adjacent to the image sensor (600), aberrations such as spherical aberration and chromatic aberration can be improved by the lens surface having an aspherical surface, and the influence on the resolution can be controlled. In addition, by arranging the plastic lens as the lens adjacent to the image sensor (600), it can be insensitive to assembly tolerances compared to a glass lens. In other words, being insensitive to assembly tolerances means that even if the assembly is slightly different 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 (600) as plastic, the optical performance can be improved by the lens surface having an aspherical surface, and for example, aberration characteristics can be improved and resolution deterioration can be prevented.

[0307]

[0308] LensSurfaceRadiusThicknessndvdSemiApertureFocal length1S1-1,188.6120.9001.52644.964-8.396 S24.3913.3943.5142S3-5.6590.9001.63233.250-12.966 S4-19.1580.1003.4553 S5123.3331.91353.6356.488S6-10.2401.7483.743 StopInfinity0.4523.1174S7-7.2461.4471.54563.11450.957 S8-6.1290.4763.1005S98.0482.5651.54553.3809.204 S10-11.4420.0683.2506S11-8.5060.9001.63233.211-6.171 S127.5120.5023.2987S135.7072.2091.54564.00010.098 S14-95.0610.8734.090 FilterS15Infinity0.5001.52643.911Infinity S16Infinity0.1003.960 Image Infinity-0.1364.628

[0309]

[0310] Table 4 shows the surface number (Surface), radius of curvature (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 (Fcoal length) of the lens according to the second embodiment of the present invention. At this time, the unit of the radius of curvature and thickness or distance may be mm.

[0311]

[0312] Item ValueItem ValueF5.794ET12.6605ΣIndex11.000ET21.7309ΣAbbe311.139ET32.0613ΣCT12 .255ET41.2711ΣCG7.262ET51.1722CA_max11.517ET62.3143CA_min5.639ET71.11 74CA_Aver7.359F-number1.681CT_max3.333FOV_D92.260CT_min0.900FOV_V44.9CT_Aver1.751FOV_H80.0EPD3.446ImgH9.256BFL1.337SD9.49TD19.868TTL20.332

[0313]

[0314] Table 5 shows the items of the mathematical formulas described above in the optical system (1100) of the embodiment, including the total track length (TTL) (mm), back focal length (BFL), effective focal length (F) (mm), ImgH (mm), effective diameter (CA) (mm), thickness (mm), TTL (mm), the optical axis distance from the first surface (S1) to the fourteenth surface (S14) TD (mm), the optical axis distance from the stop (Stop) to the fourteenth surface (S14) SD (mm), the sum of refractive indices, the sum of Abbe numbers, the sum of thicknesses (mm), the sum of spacings between adjacent lenses, the effective diameter characteristic, the diagonal angle of view (FOV_D) (Degree), the vertical angle of view (FOV_V) (Degree), the horizontal angle of view (FOV_H) (Degree), the edge thickness (ET), the F number, etc. of the optical system (1100).

[0315]

[0316] The center thicknesses of the first to seventh lenses (201 to 207) are represented by CT1 to CT7, the edge thicknesses at the ends of the effective areas of each lens are represented by ET1 to ET7, the center gap between adjacent two lenses is represented by CG1 to CG6, and the edge gaps between the edges of each lens are represented by EG1 to EG6. Here, the center thickness of the cemented lens (145) is CT45, and the edge thickness is represented by ET45. BFL (Back focal length) is the optical axis distance from the image sensor (600) to the center of the last lens. TTL is the optical axis distance from the center of the first surface (S1) of the first lens (201) to the upper surface of the image sensor (600).

[0317] As shown in Fig. 9, among the lenses of the lens unit (200) in the second embodiment, the lens surfaces of the second, fourth, fifth, sixth, and seventh lenses (202, 204, 205, 206, and 207) may include aspherical surfaces having a 30th-order aspherical surface coefficient. For example, the second, fourth, fifth, sixth, and seventh lenses (202, 204, 205, 206, and 207) may include lens surfaces having a 30th-order aspherical surface coefficient. As described above, the aspherical surface having a 30th-order aspherical surface coefficient (a value other than "0") can significantly change the aspherical shape of the peripheral portion, and thus can effectively correct the optical performance of the peripheral portion of the field of view (FOV).

[0318] When comparing the absolute values ​​of the curvature radii of each lens, the curvature radii of the first surface (S1) of the first lens (201) on the optical axis (OA) may be the largest among the lenses, and the curvature radii of the second surface (S2) of the first lens (201) may be the smallest among the lenses. The difference between the maximum and minimum curvature radii may be 200 times or more, for example, 250 to 300 times. The curvature radii of the sensor-side surface of the glass lens arranged on the object-side surface of the plastic lens may be the smallest among the lenses. The curvature radii of the sensor-side surface of the first lens (201) arranged on the object-side surface of the second lens (202) may be the smallest among the lenses.

[0319] Since the effective diameter of a plastic lens is smaller than that of a glass lens, the lens placed on the object side of the plastic lens can have a strong refractive power to refract light through the plastic lens. In addition, the radius of curvature of the lens surface can be small to increase the refractive power.

[0320] Among the lenses, the number of surfaces having an absolute value of a curvature radius of 10 mm or less among the object-side surface and the sensor-side surface may be 7 or more and 9 or less. The absolute value of the curvature radius of the sensor-side surface (second surface (S2)) of the first lens (201), the object-side surface (third surface (S3)) of the second lens (202), the object-side surface (seventh surface (S7)) of the fourth lens (204), the sensor-side surface (eighth surface (S8)) of the fourth lens (204), the object-side surface (ninth surface (S9)) of the fifth lens (205), the object-side surface (eleventh surface (S11)) of the sixth lens (206), the sensor-side surface (twelfth surface (S12)) of the sixth lens (206), and the object-side surface (thirteenth surface (S13)) of the seventh lens (207) may be 10 mm or less. Among the lenses, there may be three or more and five or fewer surfaces with an absolute value of curvature radius of 10 mm or more and 20 mm or less on the object side and the sensor side.

[0321] The absolute values ​​of the curvature radii of the sensor side (fourth surface (S4)) of the second lens (202), the object side (fifth surface (S5)) of the third lens (203), the sensor side (sixth surface (S6)) of the third lens (203), and the sensor side (tenth surface (S10)) of the fifth lens (205) may be 10 mm or more and 20 mm or less. Among the lenses, the number of surfaces having an absolute value of a curvature radii of 90 mm or more among the object side and the sensor side may be 1 or more and 3 or less. The absolute values ​​of the curvature radii of the object side (first surface (S1)) of the first lens (201) and the sensor side (fourteenth surface (S14)) of the seventh lens (207) may be 90 mm or more.

[0322] In temperature-compensated designs that require maintaining resolution across temperatures ranging from -40 to 100 degrees Celsius, a larger radius of curvature can be advantageous. Aluminum lens barrels can be used for temperature compensation. Aluminum barrels have large manufacturing tolerances, which can significantly misalign the optical axes of individual lenses during assembly. Therefore, a larger radius of curvature can be used to reduce sensitivity to manufacturing tolerances.

[0323] The shape of the first lens (201) having a spherical shape can be designed to be gentle. If the spherical surface is positioned at the frontmost position in the optical system (1100), the performance of the lens is improved, but the assemblability may be reduced. To improve the assemblability, the shape of the first lens (201) must be designed to be gentle. In order to minimize the influence on the lens placed on the sensor side when assembling the lens in the barrel, the first lens (201) can be designed to have almost no curvature.

[0324] The absolute value of the curvature radius of the first surface (S1) of the first lens (101) may be greater than the absolute value of the curvature radius of the second surface (S2). The absolute value of the curvature radius of the third surface (S3) of the second lens (102) may be less than the absolute value of the curvature radius of the fourth surface (S4). The absolute value of the curvature radius of the fifth surface (S5) of the third lens (103) may be greater than the absolute value of the curvature radius of the sixth surface (S6). The absolute value of the curvature radius of the seventh surface (S7) of the fourth lens (104) may be greater than the absolute value of the curvature radius of the eighth surface (S8). The absolute value of the curvature radius of the ninth surface (S9) of the fifth lens (105) may be less than the absolute value of the curvature radius 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). The absolute value of the radius of curvature of the thirteenth surface (S13) of the seventh lens (107) may be less than the absolute value of the radius of curvature of the fourteenth surface (S14).

[0325] The ratio of the radius of curvature of each lens can satisfy the following conditions.

[0326] Condition 1: 250 < |L1R1 / L1R2| < 270

[0327] Condition 2: 0.1 < |L2R1 / L2R2| < 0.4

[0328] Condition 3: 1 < |L3R1 / L3R2| < 1.5

[0329] Condition 4: 1 < |L4R1 / L4R2| < 1.5

[0330] Condition 5: 0.5 < |L5R1 / L5R2| < 1

[0331] Condition 6: 1 < |L6R1 / L6R2| < 1.5

[0332] Condition 7: 0 < |L7R1 / L7R2| < 0.3

[0333]

[0334] When describing the central thickness of the lenses based on the optical axis, the central thickness (CT3) of the third lens (203) is the largest among the lenses, and the central thickness (CT2) of the second lens (202) and the central thickness (CT6) of the sixth lens are the smallest among the lenses. The difference between the maximum and minimum central thicknesses among the lenses may be in the range of 2.0 mm or more and 2.5 mm or less.

[0335] The central thickness of each lens may satisfy any one of the conditions below.

[0336] Condition 1: CT3, CT4, CT5, CT7 > CT1 = CT2 = CT6

[0337] Condition 2: CT3 > CT1, CT2, CT4, CT5, CT6, CT7

[0338] Condition 3: CT3, CT5, CT7 > CT4 > CT1, CT2, CT6

[0339] Condition 4: CT3, CT7 > CT5 > CT1, CT2, CT4, CT6

[0340] Condition 5: CT3 > CT7 > CT1, CT2, CT4, CT5, CT6

[0341]

[0342] When describing the center spacing (CG) between the lenses, the center spacing (CG1) between the first lens (201) and the second lens (202) may be the maximum, and the center spacing (CG5) between the fifth and sixth lenses (205, 206) may be the minimum. The difference between the maximum center spacing and the minimum center spacing among the spaced lens spacings may be 3.0 mm or more, for example, in the range of 3.0 mm to 3.5 mm.

[0343] The center spacing between each lens can satisfy the following conditions.

[0344] Condition 1: CG1 > CG2, CG3, CG4, CG5, CG6

[0345] Condition 2: CG1, CG3, CG4, CG6 > CG2 > CG5

[0346] Condition 3: CG1 > CG3 > CG2, CG4, CG5, CG6

[0347] Condition 4: CG1, CG3, CG6 > CG4 > CG2, CG5

[0348] Condition 5: CG1, CG2, CG3, CG4, CG6 > CG5

[0349] Condition 6: CG1, CG3 > CG6 > CG2, CG4, CG5

[0350]

[0351] Regarding the effective diameter, the lens having the maximum effective diameter may be placed between the first lens (201) closest to the object and the seventh lens (207) closest to the image sensor (600). The lens having the maximum effective diameter may be a glass lens. The lens having the maximum effective diameter may be the first lens (201). Here, the effective diameter is the average of the effective diameters on the object side and the sensor side of each lens. The lens surface having the maximum effective diameter may be the first surface (S1) of the first lens (201).

[0352] The lens having the minimum effective diameter may be any one of the plastic material lenses, and for example, the effective diameter of the fourth lens (205) may be the minimum within the lens unit (200). The lens surface having the minimum effective diameter may be the eighth surface (S8) of the fourth lens (204). The effective diameter of the plastic material lens may be smaller than the effective diameter of the glass material lens.

[0353] The effective diameter of each lens can satisfy any one of the conditions below.

[0354] Condition 1: CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0355] Condition 2: CA_L1, CA_L3, CA_L7 > CA_L2 > CA_L4, CA_L5, CA_L6,

[0356] Condition 3: CA_L1, CA_L7 > CA_L3 > CA_L2, CA_L4, CA_L5, CA_L6

[0357] Condition 4: CA_L1, CA_L2, CA_L3, CA_L5, CA_L6, CA_L7 > CA_L4

[0358] Condition 5: CA_L1, CA_L2, CA_L3, CA_L7 > CA_L5 > CA_L4, CA_L6

[0359] Condition 6: CA_L1, CA_L2, CA_L3, CA_L5, CA_L7 > CA_L6 > CA_L4

[0360] Condition 7: CA_L1 > CA_L7 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6

[0361]

[0362] In terms of refractive index, the refractive index of the third lens (203) may be the largest among the lenses and may be greater than 1.8, for example, greater than 1.9. The first lens (201) may have the smallest refractive index among the lenses. For example, the refractive index of the first lens (201) may be the smallest among the lenses and may be less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index may be 0.3 or more. The glass material closest to the stop is provided as a high refractive index lens, and the lens adjacent to the glass material lens and the lens adjacent to the image sensor (600) are provided as low refractive index lenses made of plastic material, thereby increasing the incidence efficiency and adjusting the refractive power between the glass material and the plastic material lenses to guide light to the image sensor (600).

[0363] The refractive index of each lens can satisfy any of the conditions below.

[0364] Condition 1: n2, n3, n4, n5, n6, n7 > n1

[0365] Condition 2: n3 > n2 = n6 > n1, n4, n5, n7

[0366] Condition 3: n3 > n1, n2, n4, n5, n6, n7

[0367] Condition 4: n2, n3, n6 > n4 = n5 = n7 > n1

[0368]

[0369] Comparing the Abbe numbers, the Abbe number of the first lens (201) is the largest among the lenses and may be 60 or more. The Abbe numbers of the second lens (202) and the sixth lens (206) are the smallest among the lenses and may be 25 or less. The difference between the maximum refractive index and the minimum Abbe number may be 40 or more. By providing the Abbe number of the first lens (201) as the largest and the Abbe numbers of the second lens (202) and the sixth lens (206) as the smallest, the chromatic dispersion of light traveling between the lenses made of glass can be controlled, and the chromatic dispersion between the lenses made of glass and plastic can be increased to guide it to the image sensor (600).

[0370] The Abbe number of each lens can satisfy any of the conditions below.

[0371] Condition 1: v1 > v2, v3, v4, v5, v6, v7

[0372] Condition 2: v1, v3, v4, v5, v7 > v2 = v6

[0373] Condition 3: v1, v4, v5, v7 > v3 > v2, v6

[0374] Condition 4: v1 > v4 = v7 > v2, v3, v5, v6

[0375] Condition 5: v1, v4, v7 > v5 > v2, v3, v6

[0376]

[0377] The focal lengths (F1, F2, F6) of the first, second, and sixth lenses (101, 102, and 106) may have negative (-) signs. The first, second, and sixth lenses (101, 102, and 106) may have negative (-) refractive power. The focal lengths (F3, F4, F5, F7) of the third, fourth, fifth, and seventh lenses (103, 104, 105, and 107) may have positive (+) signs. The third, fourth, fifth, and seventh lenses (103, 104, 105, and 107) may have positive (+) refractive power. The third, fourth, and fifth lenses (103, 104, and 105) having positive (+) refractive power may be arranged on the sensor side of the second lens (102) having negative (-) refractive power. Through this, light incident from the object side can move away from the optical axis direction and then gather again in the optical axis direction, thereby forming a stable optical path.

[0378] Additionally, the fifth lens (105) and the sixth lens (106), which are adjacently arranged lenses, can satisfy the following conditions.

[0379] Condition 1: Refractive index of lens with positive refractive power < refractive index of lens with negative refractive power

[0380] Condition 2: Dispersion of a lens with positive refractive power > Dispersion of a lens with negative refractive power

[0381] Here, among the plastic lenses, the fifth lens (105) has positive refractive power and the sixth lens (106) has negative refractive power, so that according to conditions 1 and 2, the refractive index of the fifth lens (105) is smaller than the refractive index of the sixth lens (106), and the dispersion value of the fifth lens (105) is larger than the dispersion value of the sixth lens (106). The chromatic aberration occurring in the plastic lens can be corrected by the plastic lens. In addition, since the fifth lens (105) and the sixth lens (106), which are plastic lenses arranged in succession, 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, the chromatic aberration occurring in the plastic lens can be compensated for by the plastic lens.

[0382] Optical systems suffer from chromatic aberration, and chromatic aberration is corrected by using cemented lenses or two lenses arranged in series. As the temperature changes from low to high, the lenses contract and expand repeatedly. Since the amount of change in lens characteristics due to temperature changes is the same for lenses made of the same material, 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, chromatic aberration occurring in a plastic lens is corrected by using the fifth lens (105) and the sixth lens (106).

[0383]

[0384] When comparing the focal lengths in absolute values, the focal length of the fourth lens (204) is the largest among the lenses, and may be 45 or more and 55 or less. Among the lenses, the fourth lens (204) made of plastic may have the largest focal length and the smallest refractive power. The focal length of the sixth lens (206) is the smallest among the lenses, and the absolute value of the focal length of the sixth lens (206) may be 5 or more and 10 or less. Among the lenses, the sixth lens (206) made of plastic may have the smallest focal length and the largest refractive power.

[0385] Among the lenses, the lens having the minimum focal length may be the sixth lens (206). The difference between the maximum focal length and the minimum focal length may be 30 or more or 40 or more. Accordingly, the optical system may have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. in the set field of view range, and may have good optical performance in the periphery of the field of view.

[0386] The absolute value of the focal length of each lens can satisfy any of the conditions below.

[0387] Condition 1: |f2|, |f4|, |f5|, |f7| > |f1| > |f3|, |f6|

[0388] Condition 2: |f4| > |f2| > |f1|, |f3|, |f5|, |f6|, |f7|

[0389] Condition 3: |f1|, |f2|, |f4|, |f5|, |f7| > |f3| > |f6|

[0390] Condition 4: |f4| > |f1|, |f2|, |f3|, |f5|, |f6|, |f7|

[0391] Condition 5: |f2|, |f4|, |f7| > |f5| > |f1|, |f3|, |f6|

[0392] Condition 6: |f1|, |f2|, |f3|, |f4|, |f5|, |f7| > |f6|

[0393] Condition 7: |f2|, |f4| > |f7| > |f1|, |f3|, |f5|, |f6|

[0394]

[0395] Any one of the fifth to seventh lenses (105-107) made of a plastic material and arranged adjacent to the sensor side may have a different refractive power from the other two. For example, the fifth and seventh lenses (105, 107) may have positive (+) refractive power, and the sixth lens (106) may have negative (-) refractive power. The absolute value of the focal length of one lens having a different refractive power from the other two among the fifth to seventh lenses (105-107) may be smaller than the absolute values ​​of the focal lengths of the other two. The refractive power of one lens having a different refractive power from the other two among the fifth to seventh lenses (105-107) may be larger than the refractive powers of the other two. For example, the absolute value of the focal length of the sixth lens (106) having a negative (-) refractive power may be smaller than the absolute values ​​of the focal lengths of the fifth and seventh lenses (105, 107) having a positive (+) refractive power.

[0396] Since the plastic lens disposed adjacent to the image sensor (600) is sensitive to temperature changes, the composite refractive power of the plastic lens can be designed to be close to 0. In other words, the composite refractive power of the plastic lens disposed adjacent to the image sensor (600) can be reduced. Through this, the refractive power of the plastic lens, which is sensitive to temperature changes, can be offset within the plastic lens, thereby minimizing changes in the performance of the overall optical system, and minimizing the influence of the plastic lens on the optical performance of the overall optical system (1000).

[0397] The ratio of the absolute values ​​of the focal lengths of the glass lenses included in the optical system (1000) can satisfy a value of 1 or more and 1.5 or less. For example, the absolute value (|f1| / |f3|) of the ratio of the focal lengths of the first lens (101) and the third lens (103) made of glass can satisfy a value of 1.2 or more and 1.4 or less. In addition, the signs of the focal lengths of the first lens (101) and the third lens (103) made of glass can be different from each other. Through this, the overall refractive power of the optical system (1000) can be greatly affected by the glass lens that is strong against temperature changes.

[0398]

[0399] The thickness (T1) of the first lens (201) may be maximum at the edge and minimum at the center, and the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T2) of the second lens (202) may be maximum at the edge and minimum at the center, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T3) of the third lens (203) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T4) of the fourth lens (204) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1 to 1.5 times the minimum thickness. The thickness (T5) of the fifth lens (205) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 2 to 2.5 times the minimum thickness. The thickness (T6) of the sixth lens (206) may be minimum at the center and maximum at the edge, and the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T7) of the seventh lens (207) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness.

[0400] The thickness of each lens can satisfy any of the conditions below.

[0401] Condition 1: 0.3 < CT1 / ET1 < 0.5, 2.5 < ET1 / CT1 < 3

[0402] Condition 2: 0.3 < CT2 / ET2 < 0.7, 1.5 < ET2 / CT2 < 2

[0403] Condition 3: 1.5 < CT3 / ET3 < 2, 0.5 < ET3 / CT3 < 2

[0404] Condition 4: 1 < CT4 / ET4 < 1.5, 0.5 < ET4 / CT4 < 1

[0405] Condition 5: 2 < CT5 / ET5 < 2.5, 0.3 < ET5 / CT5 < 0.7

[0406] Condition 6: 0.1 < CT6 / ET6 < 0.5, 2.5 < ET6 / CT6 < 3

[0407] Condition 7: 1.5 < CT7 / ET7 < 2, 0.3 < ET7 / CT7 < 0.8

[0408] Condition 8: 0.8 < ΣCT / ΣET < 1, 1 < ΣET / ΣCT < 1.2

[0409]

[0410] Among the gaps (G1-G6) between the lenses, the first gap (G1) between the first and second lenses (201, 202) may have a minimum in the center and a maximum in the edge. The second gap (G2) between the second and third lenses (202, 203) may have a maximum in the edge and a minimum in the center. The third gap (G3) between the third and fourth lenses (203, 204) may have a maximum in the edge and a minimum in the center. The fifth gap (G5) between the fifth and sixth lenses (205, 206) may have a maximum in the center and a minimum in the edge. The sixth gap (G6) between the sixth and seventh lenses (206, 207) may have a maximum in the center and a minimum in the edge.

[0411]

[0412] FIGS. 11 to 13 are graphs showing the diffraction MTF (Modulation Transfer Function) at room temperature, low temperature, and high temperature in the optical system of FIG. 8, and are graphs showing the modulation ratio according to spatial frequency. As shown in FIGS. 11 to 13, in the second embodiment of the invention, the deviation of the MTF at low temperature or high temperature based on room temperature may be less than 10%, that is, 7% or less.

[0413] Table 6 shows changes in optical characteristics such as EFL and field of view (FOV_H) at room temperature, low temperature, and high temperature in the optical system according to the second embodiment. It can be seen that the change rate of the optical characteristics at low temperature is 5% or less, for example, 3% or less, based on room temperature, and it can be seen that the change rate of the optical characteristics at low temperature is 5% or less, for example, 3% or less, based on room temperature. In addition, Table 6 compares the MTF focus position shift in the optical system according to the second embodiment, and the MTF focus position shift at low and high temperatures can satisfy a range of 10 um or less based on room temperature, and can satisfy a range of 6 um or less, for example.

[0414] Room temperature low temperature high temperature low temperature / Room temperature high temperature / Room temperature EFL(F) 5.79 365.73 105.85 759 8.91% 101.10% FOV_H 80 80 80 100% 100% MTF focus position Shift 0.6um-1.7um 3.8um--

[0415]

[0416] Therefore, as shown in Table 6, it can be seen that the change in optical characteristics according to the temperature change from low temperature to high temperature, for example, the change rate of effective focal length (EFL) and the change rate of horizontal field of view (FOV_H), is 10% or less, that is, 5% or less, for example, in the range of 0 to 5%. This means that even if at least one or two or more plastic lenses are used, the design can enable temperature compensation for the plastic lenses, thereby preventing a decrease in the reliability of the optical characteristics.

[0417] The optical system of the second embodiment disclosed above can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only at the center of the field of view (FOV) but also at the periphery.

[0418]

[0419] An optical system according to a third embodiment of the invention will be described.

[0420] FIG. 15 is a side cross-sectional view of an optical system according to a third embodiment and a camera module having the same, FIG. 16 is a table showing aspherical coefficients of lenses in the optical system of FIG. 15, FIG. 17 is a table showing Sag values ​​of lens surfaces of the first to seventh lenses in the optical system of FIG. 15, FIG. 18 is a graph showing data on diffraction MTF (Modulation Transfer Function) at room temperature of the optical system of FIG. 15, FIG. 19 is a graph showing data on diffraction MTF at low temperature of the optical system of FIG. 15, FIG. 20 is a graph showing data on diffraction MTF at high temperature of the optical system of FIG. 15, and FIG. 21 is a graph showing data on aberration characteristics of the optical system of FIG. 15 at room temperature.

[0421] Referring to FIG. 15, the optical system (1200) includes a lens unit (300), and the lens unit (300) may include a first lens (301) to a seventh lens (307). The first to seventh lenses (301 to 307) may be sequentially arranged along the optical axis (OA) of the optical system (1200). Light corresponding to information about an object may pass through the first lens (301) to the seventh lens (307) and a filter (700) and be incident on the image sensor (600).

[0422] 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 negative (-) refractive power on 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 radius of curvature due to temperature changes in the surrounding environment, and can protect the incident side surface of the optical system (1200).

[0423] The first surface (S1) on the object side of the first lens (301) with respect to the optical axis may be convex, and the second surface (S2) on the sensor side may be concave. The first lens (301) may have a concave meniscus shape toward the sensor side. The first lens (301) may have a convex meniscus shape toward the object side. The first lens (301) is made of glass and may have a spherical surface.

[0424] The refractive index (n1) of the first lens (301) can satisfy the condition of n1>1.8 or n1>1.85. If the refractive index (n1) of the first lens (301) satisfies the condition, the radius of curvature of the first and second lenses (301, 302) can be increased, and lens manufacturing can be facilitated. If the refractive index (n1) of the first lens (301) is smaller than the condition, the lens surface must be formed to be sharply concave or convex in order to increase the refractive power of the first and second lenses (301, 302). In this case, lens manufacturing is not easy, the lens defect rate increases, and this may cause a decrease in yield.

[0425]

[0426] 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 negative (-) refractive power in 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.

[0427] The third surface (S3) on the object side of the second lens (302) with respect to the optical axis (OA) may be concave, and the fourth surface (S4) on the sensor side may be convex. The second lens (302) may have a meniscus shape that is convex toward the sensor side. The second lens (302) may have a meniscus shape that is concave toward 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 aspherical coefficients of the third and fourth surfaces (S3, S4) may be provided as S1 and S2 of L2 in FIG. 16.

[0428] Additionally, due to the refractive characteristics of the first lens (301), the first lens (301) can be further separated from the second lens (302). That is, the center spacing between the first and second lenses (301, 302) can be the largest within the lens unit.

[0429] The third surface (S3) of the second lens (302) may be provided without a critical point from the optical axis (OA) to the end of the effective area. The fourth surface (S4) of the second lens (302) may have a critical point from the optical axis (OA) to the end of the effective area. When the fourth surface (S4) has a critical point, it may be located in a range of 25% to 35%, preferably in a range of 30% to 35%, of the effective radius (r42) from the optical axis (OA). The critical point of the fourth surface (S4) may be located in a range of 1 mm to 1.8 mm, preferably in a range of 1 mm to 1.4 mm from the optical axis (OA).

[0430] The critical point of the fourth surface (S4) is a point where the sign of the slope value with respect to the optical axis (OA) and the direction perpendicular to the optical axis (OA) changes from positive (+) to negative (-) or from negative (-) to positive (+), and may mean a point where the slope value is 0. In addition, the critical point of the fourth surface (S4) may be a point where the slope value of the tangent line passing through the lens surface increases and then decreases, or a point where the slope value decreases and then increases.

[0431]

[0432] The third lens (303) may be arranged third from the object side. The third lens (303) may be arranged fifth from the sensor side. The third lens (303) may be arranged between the second lens (302) and the fourth lens (304). The third lens (303) may have positive (+) refractive power on 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.

[0433] The object-side fifth surface (S5) of the third lens (303) with respect to the optical axis is convex, and the sensor-side sixth surface (S6) may also be convex. The third lens (303) may have a convex shape on both sides. The third lens (303) may be made of glass and may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0434] The aperture (Stop) may be arranged around the sensor-side sixth surface (S6) of the third lens (303). The aperture (Stop) may be arranged around the object-side seventh surface (S7) of the fourth lens (304). The aperture can reduce the TTL within the field of view range, enabling miniaturization of the optical system. Accordingly, a decrease in the yield by weight of the optical system can be prevented, and production efficiency can be improved. In addition, the optical system can be miniaturized by reducing the TTL within the horizontal field of view (FOV_H) of 115 degrees to 125 degrees.

[0435]

[0436] 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.

[0437] The seventh surface (S7) on the object side of the fourth lens (304) with respect to the optical axis may be concave, and the eighth surface (S8) on the sensor side may be convex. The fourth lens (304) may have a meniscus shape in which the sensor side is convex. The fourth lens (304) may have a meniscus shape in which the object side is concave. The fourth lens (304) is made of a plastic material and may have an aspherical surface. At least one or both of the seventh surface (S7) and the eighth surface (S8) may be aspherical. The aspherical coefficients of the seventh and eighth surfaces (S7, S8) may be provided as S1 and S2 of L4 in FIG. 16. The seventh surface (S7) and the eighth surface (S8) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0438]

[0439] The fifth lens (305) may be arranged as the fifth lens from the object side. The fifth lens (305) may be arranged as the third lens from the sensor side. The fifth lens (305) may be arranged between the fourth lens (304) and the sixth lens (306). The fifth lens (305) may have positive (+) or negative (-) refractive power on the optical axis (OA). The fifth lens (305) may have positive (+) 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. The fifth lens (305) may be provided as the same material as the sixth lens (306).

[0440] With respect to the optical axis (OA), the ninth surface (S9) on the object side of the fifth lens (305) may be convex, and the tenth surface (S10) on the sensor side may also be convex. The fifth lens (305) may have a shape in which both sides are convex with respect to the optical axis (OA). The fifth lens (305) may be made of a plastic material and may have an aspherical surface. At least one of the ninth surface (S9) and the tenth surface (S10) may be an aspherical surface. The aspherical coefficients of the ninth and tenth surfaces (S9, S10) may be provided as S1 and S2 of L5 in FIG. 16. At least one of the ninth and tenth surfaces (S9, S10) of the fifth lens (305) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0441]

[0442] The sixth lens (306) may be arranged as the sixth lens from the object side. The sixth lens (306) may be arranged as the second lens 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 positive (+) or negative (-) refractive power on the optical axis (OA). The sixth lens (306) may have negative (-) 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.

[0443] With respect to the optical axis (OA), the object-side eleventh surface (S11) of the sixth lens (306) may be concave, and the sensor-side twelfth surface (S12) may be concave. The sixth lens (306) may have a concave shape on both sides with respect to the optical axis (OA). At least one or both of the eleventh surface (S11) and the twelfth surface (S12) may be aspherical. The aspherical coefficients of the eleventh and twelfth surfaces (S11, S12) may be provided as S1 and S2 of L6 of FIG. 16. At least one of the eleventh surface (S11) and the twelfth surface (S12) of the sixth lens (306) may be provided without at least one critical point from the optical axis (OA) to the end of the effective area.

[0444]

[0445] The seventh lens (307) may be arranged closest to the sensor side. The seventh lens (307) may be arranged farthest from the object side. The seventh lens (307) may have positive (+) or negative (-) refractive power on the optical axis (OA). The seventh lens (307) may have positive (+) refractive power. The seventh lens (307) may include a plastic or glass material. For example, the seventh lens (307) may be made of a plastic material.

[0446] The object-side 13th surface (S13) of the seventh lens (307) on the optical axis may be convex, and the sensor-side 14th surface (S14) may be convex. The seventh lens (307) may have a convex shape on both sides. At least one of the 13th surface (S13) and the 14th surface (S14) may be aspherical. For example, both the 13th surface (S13) and the 14th surface (S14) may be aspherical. The aspherical coefficients of the 13th and 14th surfaces (S13, S14) may be provided as S1 and S2 of L7 in FIG. 16.

[0447] The 13th surface (S13) of the seventh lens (307) may be provided without a critical point from the optical axis (OA) to the end of the effective area. The 14th surface (S14) of the seventh lens (307) may have a critical point from the optical axis (OA) to the end of the effective area. When the 14th surface (S14) has a critical point, it may be located in a range of 90% to 99%, preferably in a range of 90% to 95%, of the effective radius (r72) from the optical axis (OA). The critical point of the 14th surface (S14) may be located in a range of 2.5 mm to 3.5 mm, preferably in a range of 3 mm to 3.5 mm from the optical axis (OA).

[0448] The critical point of the 14th surface (S14) is a point where the sign of the slope value with respect to the optical axis (OA) and the direction perpendicular to the optical axis (OA) changes from positive (+) to negative (-) or from negative (-) to positive (+), and may mean a point where the slope value is 0. In addition, the critical point of the 14th surface (S14) may be a point where the slope value of the tangent line passing through the lens surface increases and then decreases, or a point where the slope value decreases and then increases.

[0449] The seventh lens (307) may be a plastic lens closest to the image sensor (600). In addition, by arranging two or more plastic lenses adjacent to the image sensor (600), aberrations such as spherical aberration and chromatic aberration can be improved by the lens surface having an aspherical surface, and the influence on the resolution can be controlled. In addition, by arranging the plastic lens as the lens adjacent to the image sensor (600), it can be insensitive to assembly tolerances compared to a glass lens. In other words, being insensitive to assembly tolerances means that even if the assembly is slightly different 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 (600) as plastic, the optical performance can be improved by the lens surface having an aspherical surface, and for example, aberration characteristics can be improved and resolution deterioration can be prevented.

[0450]

[0451] LensSurfaceRadiusThicknessndvdSemiApertureFocal length1S119.1440.9001.87385.758-5.717 S23.8913.2913.581 2S3-5.8131.5291.67193.536-9.675 S4-56.5440.1003.647 3 S5113.4261.92263.7465.500S6-8.1271.1233.836 StopInfinity0.4502.815 4S7-5.8121.7711.54562.812122.582 S8-5.9100.4082.800 5S98.9082.7331.54563.0958.935 S10-9.2950.0503.100 6S11-9.3720.9001.67193.055-5.431 S126.2990.1603.299 7S134.9682.4991.54563.7007.053 S14-13.1601.3813.686 FilterS15Infinity0.5003.972Infinity S16Infinity0.1004.026 Image Infinity-0.1364.626

[0452]

[0453] Table 7 shows the surface number (Surface), radius of curvature (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 (Fcoal length) of the lens according to the third embodiment of the present invention. At this time, the unit of the radius of curvature and thickness or distance may be mm.

[0454]

[0455] Item ValueItem ValueF3.970ET12.3725ΣIndex11.7346ET22.8298ΣAbbe269.2496ET31.8717ΣCT13 .7580ET41.7293ΣCG6.5131ET51.4414CA_max11.517ET62.3129CA_min5.639ET70.94 51CA_Aver7.359F-number1.632CT_max3.426FOV_D139.680CT_min0.900FOV_V66.1 CT_Aver1.965FOV_H120.0EPD2.432ImgH9.252BFL1.845SD10.35TD20.721TTL41.905

[0456]

[0457] Table 8 shows the items of the mathematical formulas described above in the optical system (1200) of the embodiment, including the total track length (TTL) (mm), back focal length (BFL), effective focal length (F) (mm), ImgH (mm), effective diameter (CA) (mm), thickness (mm), TTL (mm), the optical axis distance from the first surface (S1) to the fourteenth surface (S14) TD (mm), the optical axis distance from the stop (Stop) to the fourteenth surface (S14) SD (mm), the sum of refractive indices, the sum of Abbe numbers, the sum of thicknesses (mm), the sum of spacings between adjacent lenses, the effective diameter characteristic, the diagonal angle of view (FOV_D) (Degree), the vertical angle of view (FOV_V) (Degree), the horizontal angle of view (FOV_H) (Degree), the edge thickness (ET), the F number, etc. of the optical system (1200).

[0458]

[0459] The center thicknesses of the first to seventh lenses (301 to 307) are represented by CT1 to CT7, the edge thicknesses at the ends of the effective areas of each lens are represented by ET1 to ET7, the center gap between two adjacent lenses is represented by CG1 to CG6, and the edge gaps between the edges of each lens are represented by EG1 to EG6. The BFL (Back focal length) is the optical axis distance from the image sensor (600) 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 upper surface of the image sensor (600).

[0460] As shown in Fig. 16, among the lenses of the lens unit (300) in the third embodiment, the lens surfaces of the second, fourth, fifth, sixth, and seventh lenses (302, 304, 305, 306, and 307) may include aspherical surfaces having a 30th-order aspherical surface coefficient. For example, the second, fourth, fifth, sixth, and seventh lenses (302, 304, 305, 306, and 307) may include lens surfaces having a 30th-order aspherical surface coefficient. As described above, since the aspherical surface having a 30th-order aspherical surface coefficient (a value other than "0") can significantly change the aspherical shape of the peripheral portion, the optical performance of the peripheral portion of the field of view (FOV) can be well corrected.

[0461] When comparing the absolute values ​​of the curvature radii of each lens, the curvature radii of the fourth surface (S4) of the second lens (302) on the optical axis (OA) may be the largest among the lenses, and the curvature radii of the second surface (S2) of the first lens (301) may be the smallest among the lenses. The difference between the maximum curvature radii and the minimum curvature radii may be 10 times or more, for example, 10 to 15 times. The curvature radii of the sensor-side surface of the glass lens arranged on the object-side surface of the plastic lens may be the smallest among the lenses. The curvature radii of the sensor-side surface of the first lens (301) arranged on the object-side surface of the second lens (302) may be the smallest among the lenses.

[0462] Since the effective diameter of a plastic lens is smaller than that of a glass lens, the lens placed on the object side of the plastic lens can have a strong refractive power to refract light through the plastic lens. In addition, the radius of curvature of the lens surface can be small to increase the refractive power.

[0463] Among the lenses, there may be at least 8 and no more than 12 surfaces with an absolute value of curvature radius of 10 mm or less on the object side and sensor side. The radius of curvature of the sensor side (second surface (S2)) of the first lens (301), the object side (third surface (S3)) of the second lens (302), the sensor side (sixth surface (S6)) of the third lens (303), the object side (seventh surface (S7)) of the fourth lens (304), the sensor side (eighth surface (S8)) of the fourth lens (304), the object side (ninth surface (S9)) of the fifth lens (305), the sensor side (tenth surface (S10)) of the fifth lens (305), the object side (eleventh surface (S11)) of the sixth lens (306), the sensor side (twelfth surface (S12)) of the sixth lens (306), and the object side (thirteenth surface (S13)) of the seventh lens (307) may have an absolute value of 10 mm or less. Among the lenses, there may be two or more and four or fewer surfaces with an absolute value of curvature radius of 10 mm or more and 20 mm or less on the object side and the sensor side.

[0464] The absolute value of the curvature radius of the object-side surface (first surface (S1)) of the first lens (301), the object-side surface (fifth surface (S5)) of the third lens (303), and the sensor-side surface (fourteenth surface (S14)) of the seventh lens (307) may be 10 mm or more and 20 mm or less. Among the lenses, there may be one or more and two or less surfaces of which the absolute value of the curvature radius is 50 mm or more among the object-side and sensor-side surfaces. The absolute value of the curvature radius of the sensor-side surface (fourth surface (S4)) of the second lens (302) may be 50 mm or more.

[0465] In temperature-compensated designs that require maintaining resolution across temperatures ranging from -40 to 100 degrees Celsius, a larger radius of curvature can be advantageous. Aluminum lens barrels can be used for temperature compensation. Aluminum barrels have large manufacturing tolerances, which can significantly misalign the optical axes of individual lenses during assembly. Therefore, a larger radius of curvature can be used to reduce sensitivity to manufacturing tolerances.

[0466] The shape of the first lens (301) having a spherical shape can be designed to be gentle. If the aspherical surface is positioned at the frontmost position in the optical system (1200), the performance of the lens is improved, but the assemblability may be reduced. To improve the assemblability, the shape of the first lens (301) must be designed to be gentle. In order to minimize the influence on the lens placed on the sensor side when assembling the lens in the barrel, the first lens (301) can be designed to have almost no curvature.

[0467] The absolute value of the curvature radius of the first surface (S1) of the first lens (301) may be greater than the absolute value of the curvature radius of the second surface (S2). The absolute value of the curvature radius of the third surface (S3) of the second lens (302) may be less than the absolute value of the curvature radius of the fourth surface (S4). The absolute value of the curvature radius of the fifth surface (S5) of the third lens (303) may be greater than the absolute value of the curvature radius of the sixth surface (S6). The absolute value of the curvature radius of the seventh surface (S7) of the fourth lens (304) may be less than the absolute value of the curvature radius of the eighth surface (S8). The absolute value of the curvature radius of the ninth surface (S9) of the fifth lens (305) may be less than the absolute value of the curvature radius 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 thirteenth surface (S13) of the seventh lens (307) may be less than the absolute value of the radius of curvature of the fourteenth surface (S14).

[0468] The ratio of the radius of curvature of each lens can satisfy the following conditions.

[0469] Condition 1: 2 < |L1R1 / L1R2| < 6

[0470] Condition 2: 0.1 < |L2R1 / L2R2| < 0.2

[0471] Condition 3: 1 < |L3R1 / L3R2| < 1.5

[0472] Condition 4: 0.5 < |L4R1 / L4R2| < 1

[0473] Condition 5: 0.5 < |L5R1 / L5R2| < 1

[0474] Condition 6: 1 < |L6R1 / L6R2| < 1.5

[0475] Condition 7: 0.3 < |L7R1 / L7R2| < 0.5

[0476]

[0477] When describing the central thickness of the lenses based on the optical axis, the central thickness (CT3) of the third lens (303) is the largest among the lenses, and the central thickness (CT1) of the first lens (301) and the central thickness (CT6) of the sixth lens are the smallest among the lenses. The difference between the maximum and minimum central thicknesses among the lenses may be in the range of 2 mm or more and 3 mm or less.

[0478] The central thickness of each lens may satisfy any one of the conditions below.

[0479] Condition 1: CT2, CT3, CT4, CT5, CT7 > CT1 = CT6

[0480] Condition 2: CT3, CT4, CT5, CT7 > CT2 > CT1, CT6

[0481] Condition 3: CT3 > CT1, CT2, CT4, CT5, CT6, CT7

[0482] Condition 4: CT3, CT5, CT7 > CT4 > CT1, CT2, CT6

[0483] Condition 5: CT3 > CT5 > CT1, CT2, CT4, CT6, CT7

[0484] Condition 6: CT3, CT5 > CT7 > CT1, CT2, CT4, CT6

[0485]

[0486] When describing the center spacing (CG) between the lenses, the center spacing (CG1) between the first lens (301) and the second lens (302) may be the maximum, and the center spacing (CG5) between the fifth and sixth lenses (305, 306) may be the minimum. The difference between the maximum center spacing and the minimum center spacing among the spaced lens spacings may be 3.0 mm or more, for example, in the range of 3.0 mm to 3.5 mm.

[0487] The center spacing between each lens can satisfy the conditions below.

[0488] Condition 1: CG1 > CG2, CG3, CG4, CG5, CG6

[0489] Condition 2: CG1, CG3, CG4, CG6 > CG2 > CG5

[0490] Condition 3: CG1 > CG3 > CG2, CG4, CG5, CG6

[0491] Condition 4: CG1, CG3 > CG4 > CG2, CG5, CG6

[0492] Condition 5: CG1, CG2, CG3, CG4, CG6 > CG5

[0493] Condition 6: CG1, CG3, CG4 > CG6 > CG2, CG5

[0494]

[0495] Regarding the effective diameter, the lens having the maximum effective diameter may be placed between the first lens (301) closest to the object and the seventh lens (307) closest to the image sensor (600). The lens having the maximum effective diameter may be a glass lens. The lens having the maximum effective diameter may be the first lens (301). Here, the effective diameter is the average of the effective diameters on the object-side surface and the sensor-side surface of each lens. The lens surface having the maximum effective diameter may be the first surface (S1) of the first lens (301).

[0496] The lens having the minimum effective diameter may be any one of the plastic material lenses, and for example, the effective diameter of the fourth lens (305) may be the minimum within the lens unit (300). The lens surface having the minimum effective diameter may be the eighth surface (S8) of the fourth lens (304). The effective diameter of the plastic material lens may be smaller than the effective diameter of the glass material lens.

[0497] The effective diameter of each lens can satisfy any one of the conditions below.

[0498] Condition 1: CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0499] Condition 2: CA_L1, CA_L3, CA_L7 > CA_L2 > CA_L4, CA_L5, CA_L6

[0500] Condition 3: CA_L1 > CA_L3 > CA_L2, CA_L4, CA_L5, CA_L6, CA_L7

[0501] Condition 4: CA_L1, CA_L2, CA_L3, CA_L5, CA_L6, CA_L7 > CA_L4

[0502] Condition 5: CA_L1, CA_L2, CA_L3, CA_L6, CA_L7 > CA_L5 > CA_L4

[0503] Condition 6: CA_L1, CA_L2, CA_L3, CA_L7 > CA_L6 > CA_L4, CA_L5

[0504] Condition 7: CA_L1, CA_L3 > CA_L7 > CA_L2, CA_L4, CA_L5, CA_L6

[0505]

[0506] In terms of refractive index, the refractive index of the third lens (303) may be the largest among the lenses and may be greater than 1.8, for example, greater than 1.9. The fourth lens (304), the fifth lens (305), and the seventh lens (307) may have the smallest refractive index among the lenses. For example, the refractive indices of the fourth lens (304), the fifth lens (305), and the seventh lens (307) may be the smallest among the lenses and may be less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index may be 0.3 or more. The glass material closest to the stop is provided as a high refractive index lens, and the lens adjacent to the glass material lens and the lens adjacent to the image sensor (600) are provided as low refractive index lenses made of plastic material, thereby increasing the incidence efficiency and adjusting the refractive power between the lenses made of glass material and plastic material to guide light to the image sensor (600).

[0507] The refractive index of each lens can satisfy any of the conditions below.

[0508] Condition 1: n3 > n1 > n2, n4, n5, n6, n7

[0509] Condition 2: n1, n3 > n2 = n6 > n4, n5, n7

[0510] Condition 3: n3 > n1, n2, n4, n5, n6, n7

[0511] Condition 4: n1, n2, n3, n6 > n4 = n5 = n7

[0512]

[0513] Comparing the Abbe numbers, the Abbe numbers of the fourth lens (304), the fifth lens (305), and the seventh lens (307) are the largest among the lenses and may be 50 or more. The Abbe number of the second lens (302) is the smallest among the lenses and may be 20 or less. The difference between the maximum Abbe number and the minimum Abbe number may be 30 or more. By making the Abbe numbers of the fourth lens (304), the fifth lens (305), and the seventh lens (307) the largest and providing the Abbe number of the second lens (302) the smallest, the chromatic dispersion of light traveling between the lenses made of glass can be controlled, and the chromatic dispersion between the lenses made of glass and plastic can be increased to guide it to the image sensor (600).

[0514] The Abbe number of each lens can satisfy any of the conditions below.

[0515] Condition 1: v4, v5, v7 > v1 > v2, v3, v6

[0516] Condition 2: v1, v3, v4, v5, v6, v7 > v2

[0517] Condition 3: v1, v4, v5, v7 > v3 > v2, v6

[0518] Condition 4: v4 = v5 = v7 > v1, v2, v3, v6

[0519] Condition 5: v1, v3, v4, v5, v7 > v6 > v2

[0520]

[0521] The focal lengths (F1, F2, F6) of the first, second, and sixth lenses (301, 302, and 306) may have negative (-) signs. The first, second, and sixth lenses (301, 302, and 306) may have negative (-) refractive power. The focal lengths (F3, F4, F5, F7) of the third, fourth, fifth, and seventh lenses (303, 304, 305, and 307) may have positive (+) signs. The third, fourth, fifth, and seventh lenses (303, 304, 305, and 307) may have positive (+) refractive power. The third, fourth, and fifth lenses (303, 304, and 305) having positive (+) refractive power may be arranged on the sensor side of the second lens (302) having negative (-) refractive power. Through this, light incident from the object side can move away from the optical axis direction and then gather again in the optical axis direction, thereby forming a stable optical path.

[0522] Additionally, the fifth lens (305) and the sixth lens (306), which are adjacently arranged lenses, can satisfy the following conditions.

[0523] Condition 1: Refractive index of lens with positive refractive power < refractive index of lens with negative refractive power

[0524] Condition 2: Dispersion of a lens with positive refractive power > Dispersion of a lens with negative refractive power

[0525] Here, among the plastic lenses, the fifth lens (305) has positive refractive power and the sixth lens (306) has negative refractive power, so that according to conditions 1 and 2, the refractive index of the fifth lens (305) is smaller than the refractive index of the sixth lens (306), and the dispersion value of the fifth lens (305) is larger than the dispersion value of the sixth lens (306). The chromatic aberration occurring in the plastic lens can be corrected by the plastic lens. In addition, since the fifth lens (305) and the sixth lens (306), which are plastic lenses arranged in succession, 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, the chromatic aberration occurring in the plastic lens can be compensated for by the plastic lens.

[0526] Optical systems suffer from chromatic aberration, and chromatic aberration is corrected by using cemented lenses or two lenses arranged in series. As the temperature changes from low to high, the lenses contract and expand repeatedly. Since the amount of change in lens characteristics due to temperature changes is the same for lenses made of the same material, 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, chromatic aberration occurring in a plastic lens is corrected by using the fifth lens (305) and the sixth lens (306).

[0527]

[0528] When comparing the focal lengths in absolute values, the focal length of the fourth lens (304) is the largest among the lenses, and may be 110 or more and 130 or less. Among the lenses, the fourth lens (304) made of plastic may have the largest focal length and the smallest refractive power. The focal length of the sixth lens (306) is the smallest among the lenses, and the absolute value of the focal length of the sixth lens (306) may be 5 or more and 8 or less. Among the lenses, the sixth lens (306) made of plastic may have the smallest focal length and the largest refractive power.

[0529] Among the lenses, the lens having the minimum focal length may be the sixth lens (306). The difference between the maximum focal length and the minimum focal length may be 100 or more or 110 or more. Accordingly, the optical system may have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. within the set angle of view range, and may have good optical performance in the periphery of the angle of view.

[0530] The absolute value of the focal length of each lens can satisfy any of the conditions below.

[0531] Condition 1: |f2|, |f4|, |f5|, |f7| > |f1| > |f3|, |f6|

[0532] Condition 2: |f4| > |f2| > |f1|, |f3|, |f5|, |f6|, |f7|

[0533] Condition 3: |f1|, |f2|, |f4|, |f5|, |f7| > |f3| > |f6|

[0534] Condition 4: |f4| > |f1|, |f2|, |f3|, |f5|, |f6|, |f7|

[0535] Condition 5: |f2|, |f4| > |f5| > |f1|, |f3|, |f6|, |f7|

[0536] Condition 6: |f1|, |f2|, |f3|, |f4|, |f5|, |f7| > |f6|

[0537] Condition 7: |f2|, |f4|, |f5| > |f7| > |f1|, |f3|, |f6|

[0538]

[0539] Any one of the fifth to seventh lenses (305-307) made of a plastic material and arranged adjacent to the sensor side may have a different refractive power from the other two. For example, the fifth and seventh lenses (305, 307) may have positive (+) refractive power, and the sixth lens (306) may have negative (-) refractive power. The absolute value of the focal length of one lens among the fifth to seventh lenses (305-307) having a different refractive power from the other two may be smaller than the absolute values ​​of the focal lengths of the other two. The refractive power of one lens among the fifth to seventh lenses (305-307) having a different refractive power from the other two may be larger than the refractive powers of the other two. For example, the absolute value of the focal length of the sixth lens (306) having a negative (-) refractive power may be smaller than the absolute values ​​of the focal lengths of the fifth and seventh lenses (305, 307) having a positive (+) refractive power.

[0540] Since the plastic lens disposed adjacent to the image sensor (600) is sensitive to temperature changes, the composite refractive power of the plastic lens can be designed to be close to 0. In other words, the composite refractive power of the plastic lens disposed adjacent to the image sensor (600) can be reduced. Through this, the refractive power of the plastic lens, which is sensitive to temperature changes, can be offset within the plastic lens, thereby minimizing changes in the performance of the overall optical system, and minimizing the influence of the plastic lens on the optical performance of the overall optical system (1200).

[0541] The ratio of the absolute values ​​of the focal lengths of the glass lenses included in the optical system (1200) can satisfy a value of 1 or more and 1.5 or less. For example, the absolute value (|f1| / |f3|) of the ratio of the focal lengths of the first lens (301) and the third lens (303) made of glass can satisfy a value of 1 or more and 1.2 or less. In addition, the signs of the focal lengths of the first lens (301) and the third lens (303) made of glass can be different from each other. Through this, the overall refractive power of the optical system (1200) can be greatly affected by the glass lens that is strong against temperature changes.

[0542]

[0543] The thickness (T1) of the first lens (301) may be maximum at the edge and minimum at the center, and the maximum thickness is in the range of 2 to 3 times the minimum thickness. The thickness (T2) of the second lens (302) may be maximum at the edge and minimum at the center, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T3) of the third lens (303) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T4) of the fourth lens (304) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1 to 1.5 times the minimum thickness. The thickness (T5) of the fifth lens (305) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T6) of the sixth lens (306) may be minimum at the center and maximum at the edge, and the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T7) of the seventh lens (307) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 2.5 to 3 times the minimum thickness.

[0544] The thickness of each lens can satisfy any of the conditions below.

[0545] Condition 1: 0.2 < CT1 / ET1 < 0.5, 2 < ET1 / CT1 < 3

[0546] Condition 2: 0.3 < CT2 / ET2 < 0.7, 1.5 < ET2 / CT2 < 2

[0547] Condition 3: 1.5 < CT3 / ET3 < 2, 0.5 < ET3 / CT3 < 1

[0548] Condition 4: 1 < CT4 / ET4 < 1.5, 0.5 < ET4 / CT4 < 1

[0549] Condition 5: 1.5 < CT5 / ET5 < 2, 0.3 < ET5 / CT5 < 0.7

[0550] Condition 6: 0.1 < CT6 / ET6 < 0.5, 2.5 < ET6 / CT6 < 3

[0551] Condition 7: 2.5 < CT7 / ET7 < 3, 0.3 < ET7 / CT7 < 0.8

[0552] Condition 8: 0.8 < ΣCT / ΣET < 1, 1 < ΣET / ΣCT < 1.2

[0553]

[0554] Among the gaps (G1-G6) between the lenses, the first gap (G1) between the first and second lenses (301, 302) may have a maximum in the center and a minimum in the edge. The second gap (G2) between the second and third lenses (302, 303) may have a maximum in the edge and a minimum in the center. The third gap (G3) between the third and fourth lenses (303, 304) may have a maximum in the edge and a minimum in the center. The fifth gap (G5) between the fifth and sixth lenses (305, 306) may have a minimum in the center and a maximum in the edge. The sixth gap (G6) between the sixth and seventh lenses (306, 307) may have a minimum in the center and a maximum in the edge.

[0555]

[0556] Figures 18 to 20 are graphs showing the diffraction MTF (Modulation Transfer Function) at room temperature, low temperature, and high temperature in the optical system of Figure 15, and are graphs showing the modulation ratio according to the spatial frequency. As shown in Figures 18 to 20, in the third embodiment of the invention, the deviation of the MTF at low temperature or high temperature based on room temperature may be less than 10%, that is, 7% or less.

[0557] Table 9 shows changes in optical characteristics such as EFL 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 change rate of the optical characteristics at low temperature is 5% or less, for example, 3% or less, based on room temperature, and it can be seen that the change rate of the optical characteristics at low temperature is 5% or less, for example, 3% or less, based on room temperature. In addition, Table 9 compares the MTF focus position shift in the optical system according to the third embodiment, and the MTF focus position shift at low and high temperatures can satisfy a range of 10 um or less based on room temperature, and can satisfy a range of 6 um or less, for example.

[0558] Room temperature low temperature high temperature low temperature / Room temperature high temperature / Room temperature EFL(F) 3.96993.92194.042198.79 %301.82%FOV_H120120120100%100%MTF focus position Shift-0.1um-2.9um2.2um--

[0559]

[0560] Therefore, as shown in Table 9, it can be seen that the change in optical characteristics according to the temperature change from low temperature to high temperature, for example, the change rate of effective focal length (EFL) and the change rate of horizontal field of view (FOV_H), is 10% or less, that is, 5% or less, for example, in the range of 0 to 5%. This means that even if at least one or two or more plastic lenses are used, the design can enable temperature compensation for the plastic lenses, thereby preventing a decrease in the reliability of the optical characteristics.

[0561] The optical system of the third embodiment disclosed above can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only at the center of the field of view (FOV) but also at the periphery.

[0562]

[0563] An optical system according to a fourth embodiment of the invention will be described.

[0564] FIG. 22 is a side cross-sectional view of an optical system according to a fourth embodiment and a camera module having the same, FIG. 23 is a table showing aspherical coefficients of lenses in the optical system of FIG. 22, FIG. 24 is a table showing Sag values ​​of lens surfaces of the first to seventh lenses in the optical system of FIG. 22, FIG. 25 is a graph showing data on diffraction MTF (Modulation Transfer Function) at room temperature of the optical system of FIG. 22, FIG. 26 is a graph showing data on diffraction MTF at low temperature of the optical system of FIG. 22, FIG. 27 is a graph showing data on diffraction MTF at high temperature of the optical system of FIG. 22, and FIG. 28 is a graph showing data on aberration characteristics of the optical system of FIG. 22 at room temperature.

[0565] Referring to FIG. 22, the optical system (1300) includes a lens unit (400), and the lens unit (400) may include a first lens (401) to a seventh lens (407). The first to seventh lenses (401 to 407) may be sequentially arranged along the optical axis (OA) of the optical system (1300). Light corresponding to information about an object may pass through the first lens (401) to the seventh lens (407) and a filter (700) and be incident on the image sensor (600).

[0566] 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 negative refractive power on 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 may reduce changes in the center position and radius of curvature due to temperature changes in the surrounding environment, and may protect the incident side surface of the optical system (1300).

[0567] The first surface (S1) on the object side of the first lens (401) with respect to the optical axis may be convex, and the second surface (S2) on the sensor side may be concave. The first lens (401) may have a meniscus shape in which the object side is convex. The first lens (401) may have a meniscus shape in which the sensor side is concave. The first lens (401) is made of glass and may have a spherical surface.

[0568] The refractive index (n1) of the first lens (401) can satisfy the condition of n1>1.8 or n1>1.9. If the refractive index (n1) of the first lens (401) satisfies the condition, the radius of curvature of the first and second lenses (401, 402) can be increased, and lens manufacturing can be facilitated. If the refractive index (n1) of the first lens (401) is smaller than the condition, the lens surface must be formed to be sharply concave or convex in order to increase the refractive power of the first and second lenses (401, 402). In this case, lens manufacturing is not easy, the lens defect rate increases, and it may cause a decrease in yield.

[0569]

[0570] 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 negative refractive power in 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.

[0571] The object-side third surface (S3) of the second lens (402) is concave with respect to the optical axis (OA), and the sensor-side fourth surface (S4) may also be concave. The second lens (402) may have a concave shape on both sides. 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 aspherical coefficients of the third and fourth surfaces (S3, S4) may be provided as S1 and S2 of L2 in FIG. 23. At least one or both of the third surface (S3) and the fourth surface (S4) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0572] Additionally, due to the refractive characteristics of the first lens (401), the first lens (401) can be further separated from the second lens (402). That is, the center spacing between the first and second lenses (401, 402) can be the largest within the lens unit.

[0573]

[0574] The third lens (403) may be arranged third from the object side. The third lens (403) may be arranged fifth from the sensor side. The third lens (403) may be arranged between the second lens (402) and the fourth lens (404). The third lens (403) may have positive (+) refractive power on 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.

[0575] The object-side fifth surface (S5) of the third lens (403) with respect to the optical axis is convex, and the sensor-side sixth surface (S6) may also be convex. The third lens (403) may have a convex shape on both sides. The third lens (403) may be made of glass and may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be spherical. At least one or both of the fifth surface (S5) and the sixth surface (S6) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0576] The aperture (Stop) may be arranged around the sensor-side sixth surface (S6) of the third lens (403). The aperture (Stop) may be arranged around the object-side seventh surface (S7) of the fourth lens (404). The aperture can reduce the TTL within the field of view range, enabling miniaturization of the optical system. Accordingly, a decrease in the yield by weight of the optical system can be prevented, and production efficiency can be improved. In addition, the optical system can be miniaturized by reducing the TTL within the horizontal field of view (FOV_H) of 115 degrees to 125 degrees.

[0577]

[0578] 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 with a plastic material. The fourth lens (404) may be provided with the same material as the fifth lens (405).

[0579] The seventh surface (S7) on the object side of the fourth lens (404) with respect to the optical axis may be concave, and the eighth surface (S8) on the sensor side may be convex. The fourth lens (404) may have a meniscus shape in which the sensor side is convex. The fourth lens (404) may have a meniscus shape in which the object side is concave. The fourth lens (404) is made of a plastic material and may have an aspherical surface. At least one or both of the seventh surface (S7) and the eighth surface (S8) may be aspherical. The aspherical coefficients of the seventh and eighth surfaces (S7, S8) may be provided as S1 and S2 of L4 in FIG. 23. The seventh surface (S7) and the eighth surface (S8) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0580]

[0581] 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 on the optical axis (OA). The fifth lens (405) may have positive (+) refractive power. The fifth lens (405) may include a plastic or glass material. For example, the fifth lens (405) may be provided as a plastic material. The fifth lens (405) may be provided as the same material as the fourth lens (404).

[0582] With respect to the optical axis (OA), the ninth surface (S9) on the object side of the fifth lens (405) may be convex, and the tenth surface (S10) on the sensor side may also be convex. The fifth lens (405) may have a shape in which both sides are convex with respect to the optical axis (OA). The fifth lens (405) may be made of a plastic material and may have an aspherical surface. At least one of the ninth surface (S9) and the tenth surface (S10) may be an aspherical surface. The aspherical coefficients of the ninth and tenth surfaces (S9, S10) may be provided as S1 and S2 of L5 in FIG. 23. At least one or both of the ninth and tenth surfaces (S9, S10) of the fifth lens (405) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0583]

[0584] 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 on the optical axis (OA). The sixth lens (406) may have negative (-) refractive power. The sixth lens (406) may include a plastic or glass material. For example, the sixth lens (406) may be provided as a plastic material.

[0585] With respect to the optical axis (OA), the object-side eleventh surface (S11) of the sixth lens (406) may be concave, and the sensor-side twelfth surface (S12) may be concave. The sixth lens (406) may have a concave shape on both sides with respect to the optical axis (OA). At least one or both of the eleventh surface (S11) and the twelfth surface (S12) may be aspherical. The aspherical coefficients of the eleventh and twelfth surfaces (S11, S12) may be provided as S1 and S2 of L6 of FIG. 23. At least one of the eleventh surface (S11) and the twelfth surface (S12) of the sixth lens (406) may be provided without at least one critical point from the optical axis (OA) to the end of the effective area.

[0586]

[0587] The seventh lens (407) may be arranged closest to the sensor side. The seventh lens (407) may be arranged farthest from the object side. The seventh lens (407) may have positive (+) or negative (-) refractive power on the optical axis (OA). The seventh lens (407) may have positive (+) refractive power. The seventh lens (407) may include a plastic or glass material. For example, the seventh lens (407) may be made of a plastic material.

[0588] The object-side 13th surface (S13) of the seventh lens (407) on the optical axis may be convex, and the sensor-side 14th surface (S14) may also be convex. The seventh lens (407) may have a convex shape on both sides. At least one of the 13th surface (S13) and the 14th surface (S14) may be aspherical. For example, both the 13th surface (S13) and the 14th surface (S14) may be aspherical. The aspherical coefficients of the 13th and 14th surfaces (S13, S14) may be provided as S1 and S2 of L7 in FIG. 23.

[0589] The 13th surface (S13) of the seventh lens (407) may be provided without a critical point from the optical axis (OA) to the end of the effective area. The 14th surface (S14) of the seventh lens (407) may have a critical point from the optical axis (OA) to the end of the effective area. When the 14th surface (S14) has a critical point, it may be located in a range of 80% to 90%, preferably in a range of 80% to 85%, of the effective radius (r72) from the optical axis (OA). The critical point of the 14th surface (S14) may be located in a range of 2.5 mm to 3.5 mm, preferably in a range of 3 mm to 3.5 mm from the optical axis (OA).

[0590] The critical point of the 14th surface (S14) is a point where the sign of the slope value with respect to the optical axis (OA) and the direction perpendicular to the optical axis (OA) changes from positive (+) to negative (-) or from negative (-) to positive (+), and may mean a point where the slope value is 0. In addition, the critical point of the 14th surface (S14) may be a point where the slope value of the tangent line passing through the lens surface increases and then decreases, or a point where the slope value decreases and then increases.

[0591] The seventh lens (407) may be a plastic lens closest to the image sensor (600). In addition, by arranging two or more plastic lenses adjacent to the image sensor (600), aberrations such as spherical aberration and chromatic aberration can be improved by the lens surface having an aspherical surface, and the influence on the resolution can be controlled. In addition, by arranging the plastic lens as the lens adjacent to the image sensor (600), it can be insensitive to assembly tolerances compared to a glass lens. In other words, being insensitive to assembly tolerances means that even if the assembly is slightly different from the design during assembly, the optical performance may not be significantly affected. In addition, by providing the two lenses (406, 407) adjacent to the image sensor (600) as plastic, the optical performance can be improved by the lens surface having an aspherical surface, and for example, aberration characteristics can be improved and resolution deterioration can be prevented.

[0592]

[0593] LensSurfaceRadiusThicknessndvdSemiApertureFocal length1S114.6261.0251.91355.714-6.144 S23.9313.3753.571 2S3-6.1862.5181.67193.437-6.868 S421.9640.0503.270 3 S592.0331.92223.4005.300S6-9.3852.0173.250 StopInfinity0.2892.668 4S7-8.8621.8711.54562.66828.122 S8-5.9980.6642.700 5S97.0502.5851.54563.4007.352 S10-7.8340.0653.371 6S11-6.9420.9001.67193.281-5.134 S127.3510.4603.284 7S135.1992.4171.54563.9007.977 S14-20.4361.6833.650 FilterS15Infinity0.5004.027Infinity S16Infinity0.1004.099 Image Infinity-0.3404.628

[0594]

[0595] Table 10 shows the surface number (Surface), radius of curvature (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 (Fcoal length) of the lens according to the fourth embodiment of the present invention. At this time, the unit of the radius of curvature and thickness or distance may be mm.

[0596]

[0597] Item ValueItem ValueF3.702ET12.1548ΣIndex11.773ET23.8246ΣAbbe262.679ET30.8431ΣCT13. 350ET41.6693ΣCG8.3142ET50.7053CA_max11.517ET62.4668CA_min5.639ET71.184 9CA_Aver7.359F-number1.616CT_max2.585FOV_D134.700CT_min0.900FOV_V66.1CT_Aver1.907FOV_H120.0EPD2.291ImgH9.256BFL1.943SD10.93TD21.953TTL44.166

[0598]

[0599] Table 11 shows the items of the mathematical formulas described above in the optical system (1300) of the embodiment, including the total track length (TTL) (mm), back focal length (BFL), effective focal length (F) (mm), ImgH (mm), effective diameter (CA) (mm), thickness (mm), TTL (mm), the optical axis distance from the first surface (S1) to the fourteenth surface (S14) TD (mm), the optical axis distance from the stop (Stop) to the fourteenth surface (S14) SD (mm), the sum of refractive indices, the sum of Abbe numbers, the sum of thicknesses (mm), the sum of spacings between adjacent lenses, the effective diameter characteristic, the diagonal angle of view (FOV_D) (Degree), the vertical angle of view (FOV_V) (Degree), the horizontal angle of view (FOV_H) (Degree), the edge thickness (ET), the F number, etc. of the optical system (1300).

[0600]

[0601] The center thicknesses of the first to seventh lenses (401 to 407) are represented by CT1 to CT7, the edge thicknesses at the ends of the effective areas of each lens are represented by ET1 to ET7, the center gap between adjacent two lenses is represented by CG1 to CG6, and the edge gaps between the edges of each lens are represented by EG1 to EG6. Here, the center thickness of the cemented lens (145) is CT45, and the edge thickness is represented by ET45. The BFL (Back focal length) is the optical axis distance from the image sensor (600) 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 upper surface of the image sensor (600).

[0602] As shown in Fig. 23, among the lenses of the lens unit (400) in the fourth embodiment, the lens surfaces of the second, fourth, fifth, sixth, and seventh lenses (402, 404, 405, 406, and 407) may include aspherical surfaces having a 30th-order aspherical surface coefficient. For example, the second, fourth, fifth, sixth, and seventh lenses (402, 404, 405, 406, and 407) may include lens surfaces having a 30th-order aspherical surface coefficient. As described above, the aspherical surface having a 30th-order aspherical surface coefficient (a value other than "0") can significantly change the aspherical shape of the peripheral portion, and thus can effectively correct the optical performance of the peripheral portion of the field of view (FOV).

[0603] When comparing the absolute values ​​of the curvature radii of each lens, the curvature radii of the fourth surface (S4) of the second lens (402) on the optical axis (OA) may be the largest among the lenses, and the curvature radii of the second surface (S2) of the first lens (401) may be the smallest among the lenses. The difference between the maximum curvature radii and the minimum curvature radii may be 3 times or more, for example, 4 to 6 times. The curvature radii of the sensor-side surface of the glass-material lens arranged on the object-side surface of the plastic-material lens may be the smallest among the lenses. The curvature radii of the sensor-side surface of the first lens (401) arranged on the object-side surface of the second lens (402) may be the smallest among the lenses.

[0604] Since the effective diameter of a plastic lens is smaller than that of a glass lens, the lens placed on the object side of the plastic lens can have a strong refractive power to refract light through the plastic lens. In addition, the radius of curvature of the lens surface can be small to increase the refractive power.

[0605] Among the lenses, there may be 10 or more, and 12 or fewer, surfaces with an absolute value of curvature radius of 10 mm or less on the object side and sensor side. The sensor side (second surface (S2)) of the first lens (401), the object side (third surface (S3)) of the second lens (402), the object side (seventh surface (S5)) of the third lens (403), the sensor side (sixth surface (S6)) of the third lens (404), the object side (seventh surface (S7)) of the fourth lens (404), the sensor side (eighth surface (S8)) of the fourth lens (404), the object side (ninth surface (S9)) of the fifth lens (405), the sensor side (tenth surface (S10)) of the fifth lens (405), the object side (eleventh surface (S11)) of the sixth lens (406), the sensor side (twelfth surface (S12)) of the sixth lens (406), the object side (thirteenth surface (S13)) of the seventh lens (407) The absolute value of the radius of curvature may be 10 mm or less. Among the lenses, there may be at least one and no more than two surfaces on the object side and the sensor side whose absolute value of the radius of curvature is 10 mm or more and 20 mm or less.

[0606] The absolute value of the curvature radius of the object-side surface (the first surface (S1)) of the first lens (402) may be 10 mm or more and 20 mm or less. Among the lenses, the number of surfaces having an absolute value of a curvature radius of 20 mm or more among the object-side surface and the sensor-side surface may be 1 or more and 3 or less. The absolute value of the curvature radius of the sensor-side surface (the fourth surface (S4)) of the second lens (402) and the sensor-side surface (the fourteenth surface (S14)) of the seventh lens (407) may be 20 mm or more.

[0607] In temperature-compensated designs that require maintaining resolution across temperatures ranging from -40 to 100 degrees Celsius, a larger radius of curvature can be advantageous. Aluminum lens barrels can be used for temperature compensation. Aluminum barrels have large manufacturing tolerances, which can significantly misalign the optical axes of individual lenses during assembly. Therefore, a larger radius of curvature can be used to reduce sensitivity to manufacturing tolerances.

[0608] The shape of the first lens (401) having an aspherical shape can be designed to be gentle. If the aspherical surface is positioned at the frontmost part of the optical system (1300), the performance of the lens is improved, but the assemblability may be reduced. To improve the assemblability, the shape of the first lens (401) must be designed to be gentle. In order to minimize the influence on the lens placed on the sensor side when assembling the lens into the barrel, the first lens (401) can be designed to have almost no curvature.

[0609] The absolute value of the curvature radius of the first surface (S1) of the first lens (401) may be greater than the absolute value of the curvature radius of the second surface (S2). The absolute value of the curvature radius of the third surface (S3) of the second lens (402) may be less than the absolute value of the curvature radius of the fourth surface (S4). The absolute value of the curvature radius of the fifth surface (S5) of the third lens (403) may be less than the absolute value of the curvature radius of the sixth surface (S6). The absolute value of the curvature radius of the seventh surface (S7) of the fourth lens (404) may be greater than the absolute value of the curvature radius of the eighth surface (S8). The absolute value of the curvature radius of the ninth surface (S9) of the fifth lens (405) may be less than the absolute value of the curvature radius 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 smaller than the absolute value of the radius of curvature of the twelfth surface (S12). The absolute value of the radius of curvature of the thirteenth surface (S13) of the seventh lens (407) may be smaller than the absolute value of the radius of curvature of the fourteenth surface (S14).

[0610] The ratio of the radius of curvature of each lens can satisfy the following conditions.

[0611] Condition 1: 1 < |L1R1 / L1R2| < 5

[0612] Condition 2: 0.1 < |L2R1 / L2R2| < 0.4

[0613] Condition 3: 0.5 < |L3R1 / L3R2| < 1

[0614] Condition 4: 1 < |L4R1 / L4R2| < 1.5

[0615] Condition 5: 0.5 < |L5R1 / L5R2| < 1

[0616] Condition 6: 0.5 < |L6R1 / L6R2| < 1

[0617] Condition 7: 0 < |L7R1 / L7R2| < 0.3

[0618]

[0619] When describing the central thickness of the lenses based on the optical axis, the central thickness (CT5) of the fifth lens (405) is the largest among the lenses, and the central thickness (CT6) of the sixth lens (406) is the smallest among the lenses. The difference between the maximum and minimum central thicknesses among the lenses may be in the range of 1.5 mm or more and 2.0 mm or less.

[0620] The central thickness of each lens may satisfy any one of the conditions below.

[0621] Condition 1: CT2, CT3, CT4, CT5, CT7 > CT1 > CT6

[0622] Condition 2: CT5 > CT2 > CT1, CT3, CT4, CT6, CT7

[0623] Condition 3: CT2, CT5, CT7 > CT3 > CT1, CT4, CT6

[0624] Condition 4: CT2, CT3, CT5, CT7 > CT4 > CT1, CT6

[0625] Condition 5: CT5 > CT1, CT2, CT3, CT4, CT6, CT7

[0626] Condition 6: CT1, CT2, CT3, CT4, CT5, CT7 > CT6

[0627] Condition 7: CT2, CT5 > CT7 > CT1, CT3, CT4, CT6

[0628]

[0629]

[0630] When describing the center spacing (CG) between the lenses, the center spacing (CG1) between the first lens (401) and the second lens (402) may be maximum, and the center spacing (CG2) between the second and third lenses (402, 403) may be minimum. The difference between the maximum center spacing and the minimum center spacing among the spaced lens spacings may be 3.0 mm or more, for example, in the range of 3.0 mm to 3.5 mm.

[0631] The center spacing between each lens can satisfy the following conditions.

[0632] Condition 1: CG1 > CG2, CG3, CG4, CG5, CG6

[0633] Condition 2: CG1, CG3, CG4, CG5, CG6 > CG2

[0634] Condition 3: CG1 > CG3 > CG2, CG4, CG5, CG6

[0635] Condition 4: CG1, CG3 > CG4 > CG2, CG5, CG6

[0636] Condition 5: CG1, CG3, CG4, CG6 > CG5 > CG2

[0637] Condition 6: CG1, CG3, CG4 > CG6 > CG2, CG5

[0638]

[0639] Regarding the effective diameter, the lens having the maximum effective diameter may be placed between the first lens (401) closest to the object and the seventh lens (407) closest to the image sensor (600). The lens having the maximum effective diameter may be a glass lens. The lens having the maximum effective diameter may be the first lens (401). Here, the effective diameter is the average of the effective diameters of the object-side surface and the sensor-side surface of each lens. The lens surface having the maximum effective diameter may be the first surface (S1) of the first lens (401).

[0640] The lens having the minimum effective diameter may be any one of the plastic material lenses, and for example, the effective diameter of the fourth lens (404) may be the minimum within the lens unit (400). The lens surface having the minimum effective diameter may be the seventh surface (S7) of the fourth lens (404). The effective diameter of the plastic material lens may be smaller than the effective diameter of the glass material lens.

[0641] The effective diameter of each lens can satisfy any one of the conditions below.

[0642] Condition 1: CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6, CA_L7

[0643] Condition 2: CA_L1, CA_L5, CA_L7 > CA_L2 > CA_L3, CA_L4, CA_L6,

[0644] Condition 3: CA_L1, CA_L2, CA_L5, CA_L7 > CA_L3 > CA_L4, CA_L6

[0645] Condition 4: CA_L1, CA_L2, CA_L3, CA_L5, CA_L6, CA_L7 > CA_L4

[0646] Condition 5: CA_L1, CA_L7 > CA_L5 > CA_L2, CA_L3, CA_L4, CA_L6

[0647] Condition 6: CA_L1, CA_L2, CA_L3, CA_L5, CA_L7 > CA_L6 > CA_L4

[0648] Condition 7: CA_L1 > CA_L7 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6

[0649]

[0650] In terms of refractive index, the refractive index of the third lens (403) may be the largest among the lenses and may be greater than 1.8, for example, greater than 1.9. The fourth lens (404), the fifth lens (405), and the seventh lens (407) may have the smallest refractive index among the lenses. For example, the refractive indices of the fourth lens (404), the fifth lens (405), and the seventh lens (407) may be the smallest among the lenses and may be less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index may be 0.3 or more. The glass material closest to the stop is provided as a high refractive index lens, and the lens adjacent to the glass material lens and the lens adjacent to the image sensor (600) are provided as low refractive index lenses made of plastic material, thereby increasing the incidence efficiency and adjusting the refractive power between the lenses made of glass material and plastic material to guide light to the image sensor (600).

[0651] The refractive index of each lens can satisfy any of the conditions below.

[0652] Condition 1: n3 > n1 > n2, n4, n5, n6, n7

[0653] Condition 2: n1, n3 > n2 > n4, n5, n6, n7

[0654] Condition 3: n3 > n1, n2, n4, n5, n6, n7

[0655] Condition 4: n1, n2, n3, n6 > n4 = n5 = n7

[0656] Condition 5: n1, n2, n3 > n6 > n4, n5, n7

[0657]

[0658] Comparing the Abbe numbers, the Abbe numbers of the fourth lens (404) and the seventh lens (407) are the largest among the lenses and may be 50 or more. The Abbe number of the second lens (402) is the smallest among the lenses and may be 20 or less. The difference between the maximum Abbe number and the minimum Abbe number may be 30 or more. By providing the Abbe numbers of the fourth lens (404) and the seventh lens (407) as the largest and the Abbe number of the second lens (402) as the smallest, the chromatic dispersion of light traveling between the lenses made of glass can be controlled, and the chromatic dispersion between the lenses made of glass and plastic can be increased to guide it to the image sensor (600).

[0659]

[0660] The Abbe number of each lens can satisfy any of the conditions below.

[0661] Condition 1: v4, v5, v7 > v1 > v2, v3, v6

[0662] Condition 2: v1, v3, v4, v5, v6, v7 > v2

[0663] Condition 3: v1, v4, v5, v7 > v3 > v2, v6

[0664] Condition 4: v4 = v7 > v1, v2, v3, v5, v6

[0665] Condition 5: v4, v7 > v5 > v1, v2, v3, v6

[0666]

[0667] The focal lengths (F1, F2, F6) of the first, second, and sixth lenses (401, 402, and 406) may have negative (-) signs. The first, second, and sixth lenses (401, 402, and 406) may have negative (-) refractive power. The focal lengths (F3, F4, F5, F7) of the third, fourth, fifth, and seventh lenses (403, 404, 405, and 407) may have positive (+) signs. The third, fourth, fifth, and seventh lenses (403, 404, 405, and 407) may have positive (+) refractive power. The third, fourth, and fifth lenses (403, 404, and 405) having positive (+) refractive power may be arranged on the sensor side of the second lens (402) having negative (-) refractive power. Through this, light incident from the object side can move away from the optical axis direction and then gather again in the optical axis direction, thereby forming a stable optical path.

[0668] Additionally, the fifth lens (405) and the sixth lens (406), which are adjacently arranged lenses, can satisfy the following conditions.

[0669] Condition 1: Refractive index of lens with positive refractive power < refractive index of lens with negative refractive power

[0670] Condition 2: Dispersion of a lens with positive refractive power > Dispersion of a lens with negative refractive power

[0671] Here, among the plastic lenses, the fifth lens (405) has positive refractive power and the sixth lens (406) has negative refractive power, so that according to conditions 1 and 2, the refractive index of the fifth lens (405) is smaller than the refractive index of the sixth lens (406), and the dispersion value of the fifth lens (405) is larger than the dispersion value of the sixth lens (406). The chromatic aberration occurring in the plastic lens can be corrected by the plastic lens. In addition, since the fifth lens (405) and the sixth lens (406), which are plastic lenses arranged in succession, 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, the chromatic aberration occurring in the plastic lens can be compensated for by the plastic lens.

[0672] Optical systems suffer from chromatic aberration, and chromatic aberration is corrected by using cemented lenses or two lenses arranged in series. As the temperature changes from low to high, the lenses contract and expand repeatedly. Since the amount of change in lens characteristics due to temperature changes is the same for lenses made of the same material, it is effective to correct chromatic aberration between lenses made of the same material even when the temperature changes. Therefore, in the fourth embodiment of the present invention, chromatic aberration occurring in a plastic lens is corrected by using the fifth lens (405) and the sixth lens (406).

[0673]

[0674] When comparing the focal lengths in absolute values, the focal length of the fourth lens (404) is the largest among the lenses, and may be 25 or more and 30 or less. Among the lenses, the fourth lens (404) made of plastic may have the largest focal length and the smallest refractive power. The focal length of the sixth lens (406) is the smallest among the lenses, and the absolute value of the focal length of the sixth lens (406) may be 5 or more and 10 or less. Among the lenses, the sixth lens (406) made of plastic may have the smallest focal length and the largest refractive power.

[0675] Among the lenses, the lens having the minimum focal length may be the sixth lens (406). The difference between the maximum focal length and the minimum focal length may be 15 or more or 20 or more. Accordingly, the optical system may have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. in the set field of view range, and may have good optical performance in the periphery of the field of view.

[0676] The absolute value of the focal length of each lens can satisfy any of the conditions below.

[0677] Condition 1: |f2|, |f4|, |f5|, |f7| > |f1| > |f3|, |f6|

[0678] Condition 2: |f4|, |f5|, |f7| > |f2| > |f1|, |f3|, |f6|

[0679] Condition 3: |f1|, |f2|, |f4|, |f5|, |f7| > |f3| > |f6|

[0680] Condition 4: |f4| > |f1|, |f2|, |f3|, |f5|, |f6|, |f7|

[0681] Condition 5: |f4|, |f7| > |f5| > |f1|, |f2|, |f3|, |f6|

[0682] Condition 6: |f1|, |f2|, |f3|, |f4|, |f5|, |f7| > |f6|

[0683] Condition 7: |f4| > |f7| > |f1|, |f2|, |f3|, |f5|, |f6|

[0684]

[0685] Any one of the fifth to seventh lenses (405-407) made of a plastic material and arranged adjacent to the sensor side may have a different refractive power from the other two. For example, the fifth and seventh lenses (405, 407) may have positive (+) refractive power, and the sixth lens (406) may have negative (-) refractive power. The absolute value of the focal length of one lens among the fifth to seventh lenses (405-407) having a different refractive power from the other two may be smaller than the absolute values ​​of the focal lengths of the other two. The refractive power of one lens among the fifth to seventh lenses (405-407) having a different refractive power from the other two may be larger than the refractive powers of the other two. For example, the absolute value of the focal length of the sixth lens (406) having a negative (-) refractive power may be smaller than the absolute values ​​of the focal lengths of the fifth and seventh lenses (405, 407) having a positive (+) refractive power.

[0686] Since the plastic lens disposed adjacent to the image sensor (600) is sensitive to temperature changes, the composite refractive power of the plastic lens can be designed to be close to 0. In other words, the composite refractive power of the plastic lens disposed adjacent to the image sensor (600) can be reduced. Through this, the refractive power of the plastic lens, which is sensitive to temperature changes, can be offset within the plastic lens, thereby minimizing changes in the performance of the overall optical system, and the influence of the plastic lens on the optical performance of the overall optical system (1300) can be minimized.

[0687] The ratio of the absolute values ​​of the focal lengths of the glass lenses included in the optical system (1300) can satisfy a value of 1 or more and 1.5 or less. For example, the absolute value (|f1| / |f3|) of the ratio of the focal lengths of the first lens (401) and the third lens (403) made of glass can satisfy a value of 1.1 or more and 1.2 or less. In addition, the signs of the focal lengths of the first lens (401) and the third lens (403) made of glass can be different from each other. Through this, the overall refractive power of the optical system (1300) can be greatly affected by the glass lens that is strong against temperature changes.

[0688]

[0689] The thickness (T1) of the first lens (401) may be maximum at the edge and minimum at the center, and the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T2) of the second lens (402) may be maximum at the edge and minimum at the center, and the maximum thickness is in the range of 1.5 to 2 times the minimum thickness. The thickness (T3) of the third lens (403) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 2 to 2.5 times the minimum thickness. The thickness (T4) of the fourth lens (404) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 1 to 1.5 times the minimum thickness. The thickness (T5) of the fifth lens (405) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 3.5 to 4 times the minimum thickness. The thickness (T6) of the sixth lens (406) may be minimum at the center and maximum at the edge, and the maximum thickness is in the range of 2.5 to 3 times the minimum thickness. The thickness (T7) of the seventh lens (407) may be maximum at the center and minimum at the edge, and the maximum thickness is in the range of 2 to 2.5 times the minimum thickness.

[0690] The thickness of each lens can satisfy any of the conditions below.

[0691] Condition 1: 0.3 < CT1 / ET1 < 0.5, 2.5 < ET1 / CT1 < 3

[0692] Condition 2: 0.3 < CT2 / ET2 < 0.7, 1.5 < ET2 / CT2 < 2

[0693] Condition 3: 2 < CT3 / ET3 < 2.5, 0.5 < ET3 / CT3 < 2

[0694] Condition 4: 1 < CT4 / ET4 < 1.5, 0.5 < ET4 / CT4 < 1

[0695] Condition 5: 3.5 < CT5 / ET5 < 4, 0.3 < ET5 / CT5 < 0.7

[0696] Condition 6: 0.1 < CT6 / ET6 < 0.5, 2.5 < ET6 / CT6 < 3

[0697] Condition 7: 2 < CT7 / ET7 < 2.5, 0.3 < ET7 / CT7 < 0.8

[0698] Condition 8: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0699]

[0700] Among the gaps (G1-G6) between the lenses, the first gap (G1) between the first and second lenses (401, 402) may have a maximum in the center and a minimum in the edge. The second gap (G2) between the second and third lenses (402, 403) may have a maximum in the edge and a minimum in the center. The third gap (G3) between the third and fourth lenses (403, 404) may have a maximum in the edge and a minimum in the center. The fifth gap (G5) between the fifth and sixth lenses (405, 406) may have a minimum in the center and a maximum in the edge. The sixth gap (G6) between the sixth and seventh lenses (406, 407) may have a minimum in the center and a maximum in the edge.

[0701]

[0702] Figures 25 to 27 are graphs showing the diffraction MTF (Modulation Transfer Function) at room temperature, low temperature, and high temperature in the optical system of Figure 22, and are graphs showing the modulation ratio according to the spatial frequency. As shown in Figures 25 to 27, in the fourth embodiment of the invention, the deviation of the MTF between low temperature and high temperature based on room temperature may be less than 10%, that is, 7% or less.

[0703] Table 12 shows changes in optical characteristics such as EFL 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 change rate of the optical characteristics at low temperature is 5% or less, for example, 3% or less, based on room temperature, and it can be seen that the change rate of the optical characteristics at low temperature is 5% or less, for example, 3% or less, based on room temperature. In addition, Table 12 compares the MTF focus position shift in the optical system according to the fourth embodiment, and the MTF focus position shift at low and high temperatures can satisfy a range of 10 um or less based on room temperature, and can satisfy a range of 6 um or less, for example.

[0704] Room temperature low temperature high temperature low temperature / Room temperature high temperature / Room temperature EFL(F) 3.70 18 3.64 63 3.76 9 89 8.50% 30 1.84% FOV_H 1 2 0 1 2 0 100% 100% MTF focus position Shift 1.0um-1.2um 4.2um--

[0705]

[0706] Therefore, as shown in Table 12, it can be seen that the change in optical characteristics according to the temperature change from low temperature to high temperature, for example, the change rate of effective focal length (EFL) and the change rate of horizontal field of view (FOV_H), is 10% or less, that is, 5% or less, for example, in the range of 0 to 5%. This means that even if at least one or two or more plastic lenses are used, the design can enable temperature compensation for the plastic lenses, thereby preventing a decrease in the reliability of the optical characteristics.

[0707] The optical system of the fourth embodiment disclosed above can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only at the center of the field of view (FOV) but also at the periphery.

[0708]

[0709] The optical systems (1000, 1100, 1200, 1300) according to the first to fourth embodiments disclosed above can satisfy at least one or two or more of the mathematical equations described below. Accordingly, 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 equation, the optical systems (1000, 1100, 1200, 1300) can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only at the center of the field of view (FOV) but also at the periphery. In addition, the optical systems (1000, 1100, 1200, 1300) can have improved resolution. In addition, the thickness of the lens on the optical axis (OA) and the spacing between adjacent lenses on the optical axis (OA) described in the mathematical formulas may refer to the first to fourth embodiments disclosed above.

[0710]

[0711] The optical systems (1000, 1100, 1200, 1300) according to the first to fourth embodiments disclosed above can satisfy at least one or two or more of the mathematical equations described below. Accordingly, 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 equation, the optical systems (1000, 1100, 1200, 1300) can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only at the center of the field of view (FOV) but also at the periphery. In addition, the optical systems (1000, 1100, 1200, 1300) can have improved resolution. In addition, the thickness of the lens on the optical axis (OA) and the spacing between adjacent lenses on the optical axis (OA) described in the mathematical formulas may refer to the first to fourth embodiments disclosed above.

[0712]

[0713] [Mathematical Formula 1]

[0714] 0.05 < F / TTL < 0.3

[0715] In mathematical expression 1, F is the effective focal length of the optical system, and TTL (Total track length) means the distance (mm) on the optical axis (OA) from the vertex of the first surface (S1) of the first lens (101, 201, 301, 401) to the upper surface of the image sensor (600). Accordingly, 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 expression 1, the optical system (1000, 1100, 1200, 1300) can have an appropriate focal length in a set TTL range, and provides an optical system that can form an image while maintaining an appropriate focal length even when the temperature changes from low temperature to high temperature. If it is below the lower limit of mathematical expression 1, the refractive power of the lenses needs to be increased, making it difficult to correct spherical aberration or distortion aberration. If it is above the upper limit of mathematical expression 1, the effective diameter or TTL of the lenses may become longer, which may cause a problem of the imaging lens system becoming larger. In the first and second embodiments, mathematical expression 1 may preferably satisfy 0.06 < F / TTL < 0.29.

[0716]

[0717] [Equation 2]

[0718] 2 < TTL / ImgH < 5

[0719] In mathematical expression 2, TTL (Total track length) means the distance (mm) from the vertex of the first surface (S1) of the first lens (101, 201, 301, 401) to the upper surface of the image sensor (600) on the optical axis (OA), and ImgH means the maximum diagonal length of the image sensor (600). When mathematical expression 2 is satisfied, the optical system (1000, 1100, 1200, 1300) can have TTL for application to the vehicle image sensor (600), thereby providing improved image quality. When it is less than the lower limit of mathematical expression 2, the refractive power of the lenses needs to be increased, making it difficult to correct spherical aberration or distortion aberration, and when it exceeds the upper limit of mathematical expression 2, the effective diameter or TTL of the lenses becomes long, which may cause a problem of the imaging lens system becoming larger. In the first and second embodiments, mathematical expression 2 can preferably satisfy 2.1 < TTL / ImgH < 4.8.

[0720]

[0721] [Equation 3]

[0722] 1 < |F1| / F < 3

[0723] In mathematical expression 3, F1 is the focal length of the first lens (101, 201, 301, 401), and F is the effective focal length of the optical system. When mathematical expression 3 is satisfied, the optical system (1000, 1100, 1200, 1300) can have a set angle of view and an appropriate focal length, and an optical system for a vehicle can be provided. In addition, the angle of view can be set to be large within an appropriate TTL range through the first lens (101, 201, 301, 401) having negative (-) refractive power. When it is less than the lower limit of mathematical expression 3, the effective diameter or TTL of the lenses may become long, which may cause a problem in that the imaging lens system becomes large. If the upper limit of mathematical expression 3 is exceeded, the influence of the first lens (101, 201, 301, 401) becomes small in the entire optical system, and the refractive power of the lenses needs to be increased, which causes a problem in that correction of spherical aberration or distortion aberration becomes difficult. In the first and second embodiments, mathematical expression 3 can preferably satisfy 1.2 < |F1| / F < 1.8.

[0724]

[0725] [Equation 4]

[0726] 1 < |F2| / F < 4

[0727] In mathematical expression 4, F2 is the focal length of the second lens (102, 202, 302, 402), and F is the effective focal length of the optical system. When mathematical expression 4 is satisfied, the optical system (1000, 1100, 1200, 1300) can have a set angle of view and an appropriate focal length, and a vehicle optical system can be provided. When it is less than the lower limit of mathematical expression 4, the effective diameter or TTL of the lenses may become long, which may cause a problem of the large size of the imaging lens system. When it is more than the upper limit of mathematical expression 4, the influence of the second lens (102, 202, 302, 402) becomes small in the entire optical system, and the refractive power of the lenses needs to be increased, which causes a problem of difficulty in correcting spherical aberration or distortion aberration. In the first and second embodiments, mathematical expression 4 preferably satisfies 1.5 < |F2| / F < 2.5 can be satisfied.

[0728]

[0729] [Equation 5]

[0730] L2R1 < 0

[0731] In mathematical expression 5, L2R1 is the radius of curvature of the object-side surface (third surface (S3)) of the second lens (102, 202, 302, 402). When mathematical expression 5 is satisfied, the gap between the first lens (101, 201, 301, 401) and the second lens (102, 202, 302, 402) can be secured during lens assembly, facilitating assembly. In addition, when mathematical expression 5 is satisfied, the influence on incident light and TTL can be controlled.

[0732]

[0733] [Equation 6]

[0734] 1 < F3 / F < 2

[0735] In mathematical expression 6, F3 is the focal length of the third lens (103, 203, 303, 403), and F is the effective focal length of the optical system. When mathematical expression 6 is satisfied, the optical system (1000, 1100, 1200, 1300) can have a set angle of view and an appropriate focal length, and an optical system for a vehicle can be provided. In addition, the third lens (103, 203, 303, 403) made of glass can minimize changes in optical characteristics due to temperature changes of the entire optical system. In the first and second embodiments, mathematical expression 6 can preferably satisfy 1 < F3 / F < 1.5.

[0736]

[0737] [Equation 7]

[0738] 7 < F4 / F < 32

[0739] In mathematical expression 7, F4 is the focal length of the fourth lens (104, 204, 304, 404), and F is the effective focal length of the optical system. When mathematical expression 7 is satisfied, aberration characteristics can be secured, and a stable optical system can be formed by forming a gentle optical path at a short TTL. When it is below the lower limit of mathematical expression 7, the effective diameter or TTL of the lenses may become long, which may cause a problem of the large size of the imaging lens system. When it exceeds the upper limit of mathematical expression 7, the influence of the fourth lens (104, 204, 304, 404) in the entire optical system becomes small, and the refractive power of the lenses needs to be increased, which causes a problem of difficulty in correcting spherical aberration or distortion aberration. In the first embodiment, the second embodiment, and the fourth embodiment, mathematical expression 7 can preferably satisfy 5 < F4 / F < 9. In the third embodiment, mathematical expression 7 can preferably satisfy 30 < F4 / F < 32.

[0740]

[0741] [Equation 8]

[0742] 1.5 < n4 < 1.6

[0743] In mathematical expression 8, n4 is the refractive index of the fourth lens (104, 204, 304, 404). When mathematical expression 8 is satisfied, the fourth lens (104, 204, 304, 404) can minimize chromatic aberration by having a high refractive index among plastic lenses. In the first to fourth embodiments, mathematical expression 8 can preferably satisfy 1.52 < n4 < 1.58.

[0744]

[0745] [Equation 9]

[0746] 1 < F5 / F < 2.5

[0747] In mathematical expression 9, F5 is the focal length of the fifth lens (105, 205, 305, 405), and F is the effective focal length of the optical system. When mathematical expression 9 is satisfied, aberration characteristics can be secured, and a stable optical system can be formed by forming a gentle optical path at a short TTL. When it is below the lower limit of mathematical expression 9, the effective diameter or TTL of the lenses may become long, which may cause a problem of the large size of the imaging lens system. When it is above the upper limit of mathematical expression 9, the influence of the fifth lens (105, 205, 305, 405) in the entire optical system becomes small, and the refractive power of the lenses needs to be increased, which causes a problem of difficulty in correcting spherical aberration or distortion aberration. In the first to fourth embodiments, mathematical expression 9 can preferably satisfy 1.5 < F5 / F < 2.3.

[0748]

[0749] [Equation 10]

[0750] 1.5 < n5 < 1.6

[0751] In mathematical expression 10, n5 is the refractive index of the fifth lens (105, 205, 305, 405). When mathematical expression 10 is satisfied, the fifth lens (105, 205, 305, 405) can minimize chromatic aberration by having a high refractive index among plastic lenses. In the first to fourth embodiments, mathematical expression 10 can preferably satisfy 1.52 < n5 < 1.58.

[0752]

[0753] [Equation 11]

[0754] 1 < |F6| / F < 2

[0755] In mathematical expression 11, F6 is the focal length of the sixth lens (106, 206, 306, 406), and F is the effective focal length of the optical system. When mathematical expression 11 is satisfied, the optical system (1000, 1100, 1200, 1300) can have a set angle of view and an appropriate focal length, and a vehicle optical system can be provided. When it is less than the lower limit of mathematical expression 11, the effective diameter or TTL of the lenses may become long, which may cause a problem of the large size of the imaging lens system. When it is more than the upper limit of mathematical expression 11, the influence of the sixth lens (106, 206, 306, 406) becomes small in the entire optical system, and the refractive power of the lenses needs to be increased, which causes a problem of difficulty in correcting spherical aberration or distortion aberration. In the first to fourth embodiments, mathematical expression 11 preferably satisfies 1 < |F6| / F < 1.5 can be satisfied.

[0756]

[0757] [Equation 12]

[0758] 0.5 < CA_L1S1 / F < 4

[0759] In mathematical expression 12, CA_L1S1 is the effective diameter of the object-side surface (first surface (S1)) of the first lens (101, 201, 301, 401), and F is the effective focal length of the optical system. If it is less than the lower limit of mathematical expression 12, the effective diameter of the lens arranged in the optical system (1000, 1100, 1200, 1300) becomes the largest, which causes a problem in that the TTL becomes long. If it exceeds the upper limit of mathematical expression 12, there is a problem in that the angle of view becomes excessively larger than that satisfied by the optical system (1000, 1100, 1200, 1300). In the first to fourth embodiments, mathematical expression 12 can preferably satisfy 0.5 < CA_L1S1 / F < 3.2.

[0760]

[0761] [Equation 13]

[0762] 1.5 < F / EPD < 2

[0763] In mathematical expression 13, F represents the effective focal length of the optical system, and EPD represents the diameter of the entrance pupil (effective aperture). When mathematical expression 13 is satisfied, an image with a brightness suitable for driver monitoring can be provided, and a large amount of light can be received by the image sensor. In the first to fourth embodiments, mathematical expression 13 preferably satisfies 1.6 < F / EPD < 1.8.

[0764]

[0765] [Equation 14]

[0766] 0.01 < BFL / TTL < 0.1

[0767] In mathematical expression 14, BFL means the optical axis distance from the image sensor (600) to the center of the sensor side of the last lens, and TTL (Total track length) means the distance (mm) on the optical axis (OA) from the vertex of the first surface (S1) of the first lens (101, 201, 301, 401) to the upper surface of the image sensor (600). When mathematical expression 14 is satisfied, the optical system (1000, 1100, 1200, 1300) can have a set angle of view and an appropriate focal length, and an optical system for a vehicle can be provided. In addition, the optical system (1000, 1100, 1200, 1300) can minimize the gap between the last lens and the image sensor (600), and thus can have good optical characteristics at the periphery of the field of view (FOV). In the first to fourth embodiments, mathematical expression 14 can preferably satisfy 0.03 < BFL / TTL < 0.09.

[0768]

[0769] [Equation 15]

[0770] 0.1 < CT3 / F < 1

[0771] In mathematical expression 15, CT3 is the central thickness of the third lens (103, 203, 303, 403), and F is the effective focal length of the optical system. When mathematical expression 15 is satisfied, the entire optical system (1000, 1100, 1200, 1300) can have a short focal length within an appropriate TTL. In the first to fourth embodiments, mathematical expression 15 can preferably satisfy 0.5 < CT3 / F < 0.9.

[0772]

[0773] [Equation 16]

[0774] 0.5 < CT_Max / CG_Max < 1.5

[0775] In mathematical expression 16, CT_Max is the maximum central thickness among the lenses, and CG_Max is the maximum gap between adjacent lenses. When mathematical expression 16 is satisfied, the optical system can have good optical performance at the focal length at the set angle of view, and can reduce the TTL. In the first to fourth embodiments, mathematical expression 16 can preferably satisfy 0.6 < CT_Max / CG_Max < 1.2.

[0776]

[0777] [Equation 17]

[0778] 1.5 < CA_max / CA_min < 2.5

[0779] In mathematical expression 17, CA_max represents the maximum effective diameter among the object-side and sensor-side surfaces of the lenses, and CA_Min represents the minimum effective diameter among the object-side and sensor-side surfaces of the lenses. When mathematical expression 17 is satisfied, the optical system can set a size for a slim and compact structure while maintaining optical performance. In the first to fourth embodiments, mathematical expression 17 can preferably satisfy 1.5 < CA_max / CA_min < 2.2.

[0780]

[0781] [Equation 18]

[0782] 0.1 < ΣCG / ΣCT < 0.7

[0783] In mathematical expression 18, ΣCT is the sum of the central thicknesses of the lenses, and ΣCG is the sum of the spacings between adjacent lenses. When mathematical expression 18 is satisfied, the optical system can have good optical performance at the focal length at the set angle of view, and can reduce the TTL. In the first to fourth embodiments, mathematical expression 18 can preferably satisfy 0.3 < ΣCG / ΣCT < 0.7.

[0784]

[0785] [Equation 19]

[0786] 0.1 < CG1 / ΣCG < 1

[0787] In mathematical expression 19, CG1 is the center spacing between the first lens (101, 201, 301, 401) and the second lens (102, 202, 302, 402), and ΣCG is the sum of the spacings between adjacent lenses. When mathematical expression 19 is satisfied, the light emitted from the first lens (101, 201, 301, 401), which has a large influence in the entire optical system, sets an optical path for entering the remaining lenses, and the optical system can have good optical performance at the set angle of view and focal length. In the first to fourth embodiments, mathematical expression 19 can preferably satisfy 0.2 < CG1 / ΣCG < 0.7.

[0788]

[0789] [Equation 20]

[0790] 0.1 < CG1 / ΣCT < 0.5

[0791] In mathematical expression 20, CG1 is the center spacing 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 expression 20 is satisfied, the light emitted from the first lens (101, 201, 301, 401), which has a large influence in the entire optical system, sets an optical path for entering the remaining lenses, and the optical system can have good optical performance at the set angle of view and focal length. In the first to fourth embodiments, mathematical expression 20 can preferably satisfy 0.1 < CG1 / ΣCT < 0.3.

[0792]

[0793] [Equation 21]

[0794] 75 < FOV_H < 130

[0795] In mathematical expression 21, FOV_H represents the horizontal angle of view (Degree) of the optical system (1000, 1100, 1200, 1300), and can provide an angle of view suitable for a vehicle optical system. In the first to fourth embodiments, preferably, 75 < FOV_H < 125 can be satisfied.

[0796]

[0797] [Equation 22]

[0798] 1.5 < TTL / CA_max < 4

[0799] In mathematical expression 22, TTL (Total track length) means the distance (mm) from the vertex of the first surface (S1) of the first lens (101, 201, 301, 401) to the upper surface of the image sensor (600) on the optical axis (OA), and CA_max represents the maximum effective diameter among the object-side surfaces and the sensor-side surfaces of the lenses. When mathematical expression 22 is satisfied, the optical system can maintain good optical performance and set a size for a slim and compact structure. In the first to fourth embodiments, mathematical expression 22 can preferably satisfy 1.8 < TTL / CA_max < 3.9.

[0800]

[0801] [Equation 23]

[0802] 15 < TTL < 45

[0803] In mathematical expression 23, TTL (Total track length) means the distance (mm) from the center of the first surface (S1) of the first lens (101, 201, 301, 401) to the upper surface of the image sensor (600) on the optical axis (OA). When mathematical expression 23 is satisfied, a suitable vehicle optical system can be provided. In the first to fourth embodiments, mathematical expression 23 can preferably satisfy 20 < TTL < 45.

[0804]

[0805] [Equation 24]

[0806] 8.5 < ImgH < 9.5

[0807] Mathematical expression 24 indicates that ImgH represents the maximum diagonal length of the image sensor (600). Mathematical expression 24 can set the diagonal size of the image sensor (600) and provide an optical system having a sensor size for a vehicle. In the first to fourth embodiments, Mathematical expression 24 preferably satisfies 9 < ImgH < 9.3.

[0808]

[0809] [Equation 25]

[0810] 1 < BFL < 2

[0811] In mathematical expression 25, BFL is the optical axis distance from the image sensor (600) to the center of the sensor side of the last lens. When mathematical expression 25 is satisfied, the installation space of the filter (700) and the cover glass can be secured, and the assemblability of the components can be improved through the gap between the image sensor (600) and the last lens, and the joint reliability can be improved. When the BFL is less than the range of mathematical expression 25, some of the light traveling to the image sensor may not be transmitted to the image sensor, which may cause a decrease in resolution. When the BFL exceeds the range of mathematical expression 25, stray light may be introduced, which may deteriorate the aberration characteristics of the optical system.

[0812] In the first and second embodiments, mathematical expression 25 can preferably satisfy 1 < BFL < 1.5, and in the third and fourth embodiments, mathematical expression 25 can preferably satisfy 1.8 < BFL < 2.

[0813]

[0814] [Equation 26]

[0815] 3 < F < 6

[0816] Mathematical expression 26 can set the overall focal length (F) to suit the vehicle optical system. In the first to fourth embodiments, Mathematical expression 26 can satisfy 3.5 < F < 5.8.

[0817]

[0818] [Equation 27]

[0819]

[0820] In mathematical expression 27, Z can represent Sag, which is the distance from any position on the aspherical surface to the vertex of the aspherical surface along the optical axis. Y can represent the distance from any position on the aspherical surface to the optical axis in the direction perpendicular to the optical axis. c can represent the curvature of the lens, and K can represent the conic constant. In addition, A, B, C, D, E, and F can represent aspheric constants.

[0821]

[0822] The optical systems (1000, 1100, 1200, 1300) according to the first to fourth embodiments may satisfy at least one or two or more mathematical expressions from mathematical expressions 1 to 27. In this case, the optical systems (1000, 1100, 1200, 1300) may have improved optical characteristics. Specifically, when the optical systems (1000, 1100, 1200, 1300) satisfy at least one or two or more mathematical expressions from mathematical expressions 1 to 27, the optical systems (1000, 1100, 1200, 1300) may have improved resolution and may improve aberration and distortion characteristics. In addition, the optical system (1000, 1100, 1200, 1300) can secure a BFL (Back focal length) for applying a vehicle image sensor (600), compensate for the deterioration of optical characteristics due to temperature change, and minimize the gap between the last lens and the image sensor (600), thereby providing good optical performance in the center and periphery of the field of view (FOV).

[0823]

[0824] Table 13 shows the result values ​​for the mathematical expressions 1 to 26 described above in the optical system (1000, 1100, 1200, 1300) of the embodiment. Referring to Table 13, it can be seen that the optical system (1000, 1100, 1200, 1300) satisfies at least one, two or more, or three or more of the mathematical expressions 1 to 26. In detail, it can be seen that the optical system (1000, 1100, 1200, 1300) according to the embodiment satisfies all of the mathematical expressions 1 to 26. Accordingly, the optical system (1000, 1100, 1200, 1300) can have good optical performance and excellent optical characteristics at the center and periphery of the field of view (FOV).

[0825] Mathematical formulaExample 1Example 2Example 3Example 4Example 10.05 < F / TTL < 0.30.280.280.190.0822 < TTL / ImgH < 52.222.22.294.7731 < |F1| / F < 31.461.451.441.6641 < |F2| / F < 42.282.242.441.865L2R1 < 0SatisfiedSatisfiedSatisfiedSatisfied61 < F3 / F < 21.11.121.391.4377 < F4 / F < 327.358.830.887.681.5 < n4 < 1.61.541.541.541.5491 < F5 / F < 2.51.631.592.251.99101.5 < n5 < 1.61.541.541.541.54111 < |F6| / F < 21.0171.0651.3681.387120.5 < CA_L1S1 / F < 40.9020.8572.9013.087131.5 < F / EPD < 21.6641.6811.6321.616140.01 < BFL / TTL < 0.10.0520.0660.0870.044150.1 < CT3 / F < 10.5810.5750.8630.549160.5 < CT_Max / CG_Max < 1.51.0550.9821.0410.766171.5 < CA_max / CA_min < 2.51.6621.6012.0422.042180.1 < ΣCG / ΣCT < 0.70.3730.5130.4730.623190.1 < CG1 / ΣCG < 10.6090.540.3640.259200.1 < CG1 / ΣCT < 0.50.2270.2770.1720.1612175 < FOV_H <1308080>120120221.5 < TTL / CA_max < 41.9932.0483.8353.8352315 < TTL < 4520.53820.33221.18544.166248.5 < ImgH < 9.59.2529.2569.2529.256251 < BFL < 21.0591.3371.8451.943263 < F < 65.7115.7943.973.702

[0826]

[0827] Figures 29 and 30 are cross-sectional views of a lens module according to the present embodiment.

[0828] A lens module according to the present embodiment may include a lens unit (500) having a plurality of lenses, a first lens barrel (20) having a plurality of lenses stacked inside, a second lens barrel (30) coupled to the first lens barrel (20) and having a plurality of lenses stacked inside, a retainer (10) coupled to the first lens barrel (20), and a spacer (111, 112, 113, 114) arranged between flange portions of adjacent lenses.

[0829] The lens unit (500) may include an optical system in which three or more lenses are laminated, or an optical system in which five or more lenses are laminated. The lens unit (500) may include three to nine lenses. The lens unit (500) may include a plurality of solid lenses. The lens unit (500) may include lenses of different materials, for example, lenses made of plastic and lenses made of glass. The number of lenses made of glass may be greater or less than the number of lenses made of plastic. The lenses of the lens unit (500) may be made of the same glass or plastic material.

[0830] A part of the lens unit (500) may be stacked on the first lens barrel (20), and the remainder of the lens unit (500) may be stacked on the second lens barrel (30). The plurality of lenses stacked on the first lens barrel (20) may be referred to as a first lens group (LG1), and the plurality of lenses stacked on the second lens barrel (30) may be referred to as a second lens group (LG2). The first lens (501) and the second lens (502) may be arranged inside the first lens barrel (20). The third lens (503), the fourth lens (504), the fifth lens (505), the sixth lens (506), and the seventh lens (507) may be arranged in sequence inside the second lens barrel (30). The lens unit (500) may be aligned with the first lens (501), the second lens (502), the third lens (503), the fourth lens (504), the fifth lens (505), the sixth lens (506), and the seventh lens (507) along the optical axis from the object side toward the image sensor (600).

[0831] The average effective diameter of the first lens group (LG1) may be larger than the average effective diameter of the second lens group (LG2). The number of lenses included in the first lens group (LG1) may be smaller than the number of lenses included in the second lens group (LG2). The average center thickness of the lenses included in the first lens group (LG1) may be larger than the average center thickness of the lenses included in the second lens group (LG2). The number of glass lenses included in the first lens group (LG1) may be larger than the number of glass lenses included in the second lens group (LG2). The number of plastic lenses included in the first lens group (LG1) may be larger than the number of plastic lenses included in the second lens group (LG2).

[0832] Among the lenses included in the lens unit (500), the effective diameter of the lens that is arranged closest to the object side in the first lens barrel (20) may be the largest. The effective diameter of the lens that is arranged closest to the object side in the first lens barrel (20) may be larger than the effective diameter of the lens that is arranged closest to the sensor side in the first lens barrel (20). Among the lenses included in the lens unit (500), the effective diameter of the lens that is arranged closest to the object side in the second lens barrel (30) may be the smallest. The effective diameter of the lens that is arranged closest to the object side in the second lens barrel (30) may be smaller than the effective diameter of the lens that is arranged closest to the sensor side in the second lens barrel (30). The effective diameter of the lens that is arranged closest to the sensor side in the first lens barrel (20) may be larger than the effective diameter of the lens that is arranged closest to the object side in the second lens barrel (30).

[0833] The first lens barrel (20) can be penetrated from one end facing the object side to the other end facing the sensor side. A retainer (10) can be coupled to one end of the first lens barrel (20). A screw thread (21) for coupling with the retainer (10) can be formed on the outer circumference of the first lens barrel (20). A screw thread (11) for coupling with the first lens barrel (20) can be formed on the inner circumference of the retainer (10). The retainer (10) can be coupled to the first lens barrel (20) by any one of a force-fit method, adhesive decoration, and screw coupling.

[0834] The retainer (10) can be formed to surround a portion of the lens that is positioned closest to the object side of the first lens barrel (20) and the first lens barrel (20). The retainer (10) can prevent foreign substances from entering the first lens barrel (20). The retainer (10) can press the first lens group (LG1) positioned in the first lens barrel (20) inward to fix the position with respect to the first lens barrel (20). A guard ring for buffering or the like can be positioned between the retainer (10) and the first lens (501) or between the retainer (10) and the first lens barrel (20).

[0835] In the first lens barrel (20), an opening facing one end and an opening facing the other end may be connected to each other. Here, one end may refer to the object side, and the other end may refer to the sensor side. The diameter of the opening facing one end of the first lens barrel (20) may be larger than the diameter of the opening facing the other end. The first lens group (LG1) may be stacked by sequentially inserting the second lens (502) and the first lens (501) through the opening facing one end of the first lens barrel (20).

[0836] In the second lens barrel (30), an opening facing one end and an opening facing the other end may be connected to each other. Here, one end may refer to the object side, and the other end may refer to the sensor side. The diameter of the opening facing one end of the second lens barrel (30) may be smaller than the diameter of the opening facing the other end. In the second lens group, a third lens (503), a fourth lens (504), a fifth lens (505), a sixth lens (506), and a seventh lens (507) may be sequentially inserted and stacked through the opening facing the other end of the second lens barrel (30). Alternatively, the third lens (503), the first spacer (111), the fourth lens (504), the fifth lens (505), the second spacer (112), the sixth lens (506), the third spacer (113), the seventh lens (507), and the fourth spacer (114) may be sequentially inserted and stacked through an opening facing the other end of the second lens barrel (30).

[0837] Through this, performance can be improved by reducing sensitivity to decenter tolerance that occurs between one assembled lens and the other assembled lens by separating the lens barrel into two and then performing optical axis alignment (AA, Active Align) for each lens group.

[0838] One end of the second lens barrel (30) may be coupled to the other end of the first lens barrel (20). The other end of the first lens barrel (20) may be engaged and coupled to one end of the second lens barrel (30). An opening facing one end of the second lens barrel (30) may include a hole formed at one side and a center of the one side. An opening facing one end of the second lens barrel (30) may be inserted into the opening facing the other end of the first lens barrel (20). An opening facing one end of the second lens barrel (30) may be inserted inside the opening facing the other end of the first lens barrel (20). The inner surface of the opening of the first lens barrel (20) may face the outer surface of the opening of the second lens barrel (30). One side of the opening facing one end of the second lens barrel (30) can face the sensor side of the lens that is positioned closest to the sensor side in the first lens barrel (20).

[0839] One end of the second lens barrel (30) may include a wing portion (32) extending in a direction perpendicular to the optical axis. The wing portion (32) may be formed at a position closer to one end than the other end of the second lens barrel (30). The wing portion (32) may serve as a guide for fixing the position of the second lens barrel (30) when it is coupled to a lens holder or bobbin.

[0840] The opening facing the other end of the first lens barrel (20) may include a first protrusion (22). The first protrusion (22) may be connected to the opening facing the other end of the first lens barrel (20). The first recessed portion (24) may be formed in a ring shape in the outer region of the first protrusion (22). The first protrusion (22) may be connected to the first recessed portion (24).

[0841] The first protrusion (22) of the first lens barrel (20) can be inserted into the second recessed portion (33) of the second lens barrel (30). The first protrusion (22) of the first lens barrel (20) can be formed in a shape corresponding to the second recessed portion (33) of the second lens barrel (30). The first recessed portion (24) of the first lens barrel (20) can be in contact with the second protrusion (36) of the second lens barrel (30).

[0842] One end of the second lens barrel (30) may have a hole formed in the opening through which the third lens (503) is exposed. A second recessed portion (33) may be formed in a ring shape on the outer area of ​​the opening facing one end of the second lens barrel (30). The second lens barrel (30) may have a second protrusion (36) formed in a protruding manner on the outer area of ​​the second recessed portion (33). The second protrusion (36) may come into contact with the first recessed portion (24) of the first lens barrel (20). The opening of the second lens barrel (30) is inserted into the opening of the first lens barrel (20), and the first protrusion (22) of the first lens barrel (20) is inserted into the second recessed portion (33) of the second lens barrel (30), so that the first lens barrel (20) and the second lens barrel (30) can be fixed to each other.

[0843] A first chamfered portion (23) may be formed at the boundary surface connecting the first recessed portion (24) of the first lens barrel (20) and the outer surface of the first lens barrel (20). A second chamfered portion (35) may be formed at the boundary surface connecting the second protrusion (36) and one surface of the wing portion. An adhesive (35) may be placed between the first chamfered portion (23) and the second chamfered portion (35). An adhesive (35) may be placed in the space formed by the first chamfered portion (23) and the second chamfered portion (35).

[0844] After assembling the first lens group (LG1) to the first lens barrel (20) and assembling the second lens group to the second lens barrel (30), the first lens group (LG1) of the first lens barrel (20) can be aligned along the optical axis based on the second lens group (LG2) arranged in the second lens barrel (30). After aligning the optical axis of the first lens group (LG1), an adhesive (35) is applied to the first chamfered portion (23) and the second chamfered portion (35), UV cured, and then optical inspection can be performed. Through this, the sensitivity to the decenter tolerance that occurs between the lens groups assembled in each lens barrel can be reduced, and the optical performance can be improved.

[0845] The image sensor (600) may be arranged on the optical axis of the lens unit (500) or on an axis orthogonal to the optical axis of the lens unit (500). In this case, a reflective member such as a prism may be arranged between the lens unit (500) and the image sensor (600). The image sensor (600) may perform a function of converting light passing through the lens unit (500) into image data. The image sensor (600) may be any one of a CCD (Charge Coupled Device), a CMOS (Complementary Metal-Oxide Semiconductor), a CPD, and a CID. When there are multiple image sensors (600), one may be a color (RGB) sensor, and the other may be a black and white sensor.

[0846] The camera module may include a cover glass and an optical filter disposed between the last lens of the lens unit (500) and the image sensor (600). The optical filter may be disposed between the lens unit (500) and the image sensor (600). The optical filter may filter light corresponding to a specific wavelength range of light passing through the lenses. The optical filter may be an infrared (IR) blocking filter that blocks infrared rays or an ultraviolet (UV) blocking filter that blocks ultraviolet rays, but the embodiment is not limited thereto. The optical filter may be disposed above the image sensor (600). The optical filter is disposed within the opening of the second lens barrel (30) to filter light of a specific wavelength that travels downward through the lens barrel.

[0847]

[0848] FIG. 91 is an example of a plan view of a vehicle to which a camera module or optical system according to an embodiment of the invention is applied. Referring to FIG. 91, a vehicle camera system according to an embodiment of the invention includes an image generating unit (71), a first information generating unit (72), a second information generating unit (81, 82, 83, 84, 85, 86), and a control unit (74). The image generating unit (71) may include at least one camera module (91) disposed in the vehicle, and may capture images of the front of the vehicle and / or the driver to generate a front image or an interior image of the vehicle. The image generating unit (71) may capture images of the surroundings of the vehicle in one or more directions as well as the front of the vehicle using the camera module (91), to generate an image of the surroundings of the vehicle. Here, the front image and the surrounding images may be digital images, and may include color images, black and white images, infrared images, etc. In addition, the front image and the surrounding images may include still images and moving images. The image generation unit (71) provides the driver image, the front image, and the surrounding image to the control unit (74). Next, the first information generation unit (72) may include at least one radar and / or camera placed in the vehicle, and detects the front of the vehicle to generate first detection information. Specifically, the first information generation unit (72) is placed in the vehicle, and detects the position and speed of vehicles located in front of the vehicle, the presence and position of pedestrians, etc. to generate first detection information.

[0849] By using the first detection information generated by the first information generating unit (72), the distance between the own vehicle and the vehicle in front can be controlled to be maintained at a constant level, and the stability of vehicle operation can be improved in specific preset cases, such as when the driver wants to change the driving lane of the own vehicle or when backing up and parking. The first information generating unit (72) provides the first detection information to the control unit (74). The second information generating unit (81, 82, 83, 84, 85, 86) detects each side of the own vehicle based on the front image generated by the image generating unit (71) and the first detection information generated by the first information generating unit (72), and generates second detection information. Specifically, the second information generating unit (81, 82, 83, 84, 85, 86) may include at least one radar and / or camera disposed in the own vehicle, and may detect the position and speed of vehicles located on the side of the own vehicle or capture images. Here, the second information generation units (81, 82, 83, 84, 85, 86) can be placed at the front two corners, side mirrors, and rear center and rear two corners of the vehicle, respectively.

[0850] At least one information generating unit of these vehicle camera systems may be equipped with an optical system and a camera module having the same as described in the embodiments disclosed above, and may provide or process information acquired through the front, rear, each side or corner area of ​​the vehicle to a user to enable autonomous driving or to protect the vehicle and objects from surrounding safety.

[0851] The optical system of the camera module according to an embodiment of the invention can be installed in multiple units within a vehicle to enhance safety regulations, autonomous driving functions, and convenience. Furthermore, the optical system of the camera module is used as a component for controlling systems such as the Lane Keeping Assistance System (LKAS), Lane Departure Warning System (LDWS), and Driver Monitoring System (DMS). These vehicle camera modules can achieve stable optical performance even under ambient temperature changes and offer competitive pricing, thereby ensuring the reliability of vehicle components.

[0852]

[0853] The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiments pertain. Therefore, the contents related to such combinations and modifications should be construed as falling within the scope of the present invention.

[0854] In addition, although the above description focuses on examples, these are merely examples and do not limit the present invention. Those skilled in the art to which the present invention pertains will appreciate that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the present invention. For example, each component specifically shown in the examples can be modified and implemented. In addition, differences related to such modifications and applications should be interpreted as being included within the scope of the present invention defined in the appended claims.

Claims

1. Including first to seventh lenses arranged along the optical axis, The above first lens has a negative (-) refractive power, The above second lens has negative (-) refractive power, The above fifth lens has positive (+) refractive power, The above sixth lens has a negative (-) refractive power, The above seventh lens has positive (+) refractive power, An optical system in which the third lens among the first to seventh lenses has the largest thickness on the optical axis.

2. In paragraph 1, An aperture is placed between the third lens and the fourth lens, An optical system wherein at least one lens adjacent to the aperture is made of glass.

3. In paragraph 1, The above third lens has positive (+) refractive power, The above fourth lens is an optical system having positive (+) refractive power.

4. In paragraph 1, An optical system in which the thickness of the third lens on the optical axis is greater than the distance between the third lens and the fourth lens.

5. In paragraph 1, An optical system in which the thickness of the second lens and the sixth lens among the first to seventh lenses on the optical axis is the smallest.

6. In paragraph 1, The above sixth lens is an optical system having a concave shape on both sides.

7. In any one of paragraphs 1 to 6, An optical system that satisfies the following conditions. <Conditional expression> 18 < TTL < 25 (In the above conditional expression, TTL means the distance on the optical axis from the object side of the first lens to the upper surface of the image sensor.) 8. In any one of paragraphs 1 to 6, An optical system that satisfies the following conditions. <Conditional expression> 75 < FOV_H < 90 (In the above conditional expression, FOV_H refers to the horizontal angle of view of the optical system.) 9. Including the first to seventh lenses arranged along the optical axis, The above third lens has positive (+) refractive power, The above fourth lens has positive (+) refractive power, The above fifth lens has positive (+) refractive power, The above sixth lens has a negative (-) refractive power, The above seventh lens has positive (+) refractive power, An optical system in which the thickness of the third lens on the optical axis is greater than the distance between the third lens and the fourth lens.

10. In paragraph 9, An aperture is placed between the third lens and the fourth lens, At least one lens adjacent to the aperture is made of glass, The above first lens is an optical system made of glass.

Images