Optical system and camera module

Abstract

An optical system according to one embodiment of the present invention comprises first to seventh lenses arranged along an optical axis, wherein the first lens has negative (-) refractive power, the third lens has positive (+) refractive power, the fourth lens has negative (-) refractive power, the fifth lens has positive (+) refractive power, the sixth lens has negative (-) refractive power, and, on the optical axis, the thickness of the fifth lens is greater than the thickness of the first lens.

Description

Optical system and camera module

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

[0002] ADAS (Advanced Driving Assistance System) is an advanced driver assistance system designed to assist the driver in driving. It consists of sensing the situation ahead, determining the situation based on the sensed results, and controlling the vehicle's behavior based on the situation determination. For example, ADAS sensor devices detect vehicles ahead and recognize lanes. Subsequently, once a target lane, target speed, or target ahead is determined, the vehicle's ESC (Electrical Stability Control), EMS (Engine Management System), and MDPS (Motor Driven Power Steering) are controlled. Typical examples of ADAS implementation include automatic parking systems, low-speed city driving assistance systems, and blind spot warning systems.

[0003] Sensor devices used to detect the situation ahead in ADAS include GPS sensors, laser scanners, front radar, and Lidar, but the most representative is the camera used to capture images of the front, rear, and sides of the vehicle.

[0004] Such cameras can be positioned outside or inside a vehicle to detect the surrounding conditions of the vehicle. Additionally, cameras can be positioned inside the vehicle to detect the conditions of 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 status, whether they are drowsy, whether they have been drinking, etc. Furthermore, the camera can photograph the passenger from a position adjacent to the passenger and detect whether the passenger is sleeping, their health status, etc., and provide information about the passenger to the driver.

[0005] In particular, the most important element for obtaining an image in a camera is the imaging lens that forms the image. Recently, there has been increasing interest in high performance, such as high image quality and high resolution, and research is being conducted on optical systems containing multiple lenses to achieve this. 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 outside or inside a vehicle. In this case, the camera faces the problem of being unable to uniformly produce excellent optical characteristics and aberration characteristics.

[0006] Therefore, a new optical system and camera capable of solving the aforementioned problem are required.

[0007] The embodiment aims to provide an optical system and a camera module with improved optical properties.

[0008] The embodiment aims to provide an optical system and a camera module having excellent optical performance in low to high temperature environments.

[0009] The embodiments aim to provide an optical system and a camera module capable of preventing or minimizing changes in optical properties over various temperature ranges.

[0010] To solve the above technical problem, the optical system according to the present embodiment includes first to sixth lenses arranged along an optical axis, wherein the first lens has a negative (-) refractive power, the third lens has a positive (+) refractive power, the fourth lens has a negative (-) refractive power, the fifth lens has a positive (+) refractive power, and the sixth lens has a negative (-) refractive power, and the thickness of the fifth lens along the optical axis is greater than the thickness of the first lens.

[0011] The distance between the second lens and the third lens on the optical axis may be smaller than the distance between the third lens and the fourth lens.

[0012] In the above optical axis, the fourth lens may have a meniscus shape that is convex toward the object.

[0013] In the above optical axis, the thickness of the second lens among the first to sixth lenses may be the largest.

[0014] In the above optical axis, the thickness of the fourth lens among the first to sixth lenses may be the smallest.

[0015] The above second lens may have negative (-) refractive power.

[0016] The following conditional expression may be satisfied. <Conditional Expression> 0.5 < L2R1 / L2R2 < 1 (In the above conditional expression, L2R1 is the radius of curvature of the object side of the second lens, and L2R2 is the radius of curvature of the sensor side of the second lens.)

[0017] The following condition can be satisfied. <Condition> 3 < TTL / ImgH < 4 (In the above condition, TTL is the distance from the object side of the first lens to the top plane of the image sensor along the optical axis, and ImgH is half the maximum diagonal length of the image sensor.)

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

[0019] In the above optical axis, the fifth lens has a shape that is convex on both sides, and in the above optical axis, the sixth lens may have a meniscus shape that is concave toward the object side.

[0020] Among the distances between adjacent lenses on the optical axis, the distance between the third lens and the fourth lens may be the largest.

[0021] In the above optical axis, the second lens may have a meniscus shape that is concave toward the object side.

[0022] The following conditional expression may be satisfied. <Conditional Expression> 0.5 < L4R2 / L5R1 < 1 (In the above conditional expression, L4R2 represents the radius of curvature of the sensor side of the fourth lens, and L5R1 represents the radius of curvature of the object side of the fifth lens.)

[0023] The following condition can be satisfied. <Condition> 12 < TTL < 15 (In the above condition, TTL is the distance from the object side of the first lens to the top plane of the image sensor along the optical axis.)

[0024] The following condition can be satisfied. <Condition> 2 < F < 3 (In the above condition, F is the total focal length of the optical system.)

[0025] The optical system and camera module according to the embodiment may have enhanced optical characteristics. Specifically, in the optical system according to the embodiment, a plurality of lenses may have a set thickness, refractive power, and spacing from adjacent lenses. Accordingly, the optical system and camera module according to the embodiment may have enhanced MTF characteristics, aberration control characteristics, resolution characteristics, etc., within a set angle of view range, and may have good optical performance at the periphery of the angle of view.

[0026] In addition, the optical system and camera module according to the embodiment can have good optical performance in a low to high temperature range (-40℃ to 105℃). Specifically, a plurality of lenses included in the optical system may have a set material, refractive power, and refractive index. Accordingly, if the refractive index of each lens changes due to temperature changes and the focal length of each lens changes as a result, mutual compensation can be provided by the plastic lens and the glass lens. That is, the optical system can effectively distribute the refractive power in the low to high temperature range and can prevent or minimize changes in optical characteristics in the low to high temperature range. Therefore, the optical system and camera module according to the embodiment can maintain improved optical characteristics in various temperature ranges.

[0027] In addition, the optical system and camera module according to the embodiment can satisfy the set angle of view through a mixture of plastic and glass lenses and achieve excellent optical characteristics. As a result, the optical system can provide a slimmer automotive camera module. Accordingly, the optical system and camera module can be provided for various applications and devices, and can possess excellent optical characteristics even when exposed to harsh temperature environments, such as the exterior of a vehicle or the interior of a vehicle at high temperatures during the summer.

[0028] FIG. 1 is a side cross-sectional view of an optical system according to a first embodiment and a camera module having the same.

[0029] Figure 2 is a table showing the aspherical coefficients of aspherical lenses in the optical system of Figure 1.

[0030] Figure 3 is a table showing the Sag values ​​of the lens surfaces of the first to sixth lenses in the optical system of Figure 1.

[0031] Figure 4 is a graph showing data for the diffraction MTF (Modulation Transfer Function) of the optical system of Figure 1 at low temperature.

[0032] Figure 5 is a graph showing data for the diffraction MTF of the optical system of Figure 1 at room temperature.

[0033] Figure 6 is a graph showing data for the diffraction MTF at high temperature of the optical system of Figure 1.

[0034] Figure 7 is a graph showing data on the aberration characteristics of the optical system of Figure 1 at low temperature.

[0035] Figure 8 is a graph showing data on the aberration characteristics of the optical system of Figure 1 at room temperature.

[0036] Figure 9 is a graph showing data on the aberration characteristics of the optical system of Figure 1 at high temperatures.

[0037] FIG. 10 is a side cross-sectional view of an optical system according to a second embodiment and a camera module having the same.

[0038] Figure 11 is a table showing the aspherical coefficients of aspherical lenses in the optical system of Figure 10.

[0039] FIG. 12 is a table showing the Sag values ​​of the lens surfaces of the first to sixth lenses in the optical system of FIG. 10.

[0040] Figure 13 is a graph showing data for the diffraction MTF (Modulation Transfer Function) of the optical system of Figure 10 at low temperature.

[0041] Figure 14 is a graph showing data for the diffraction MTF of the optical system of Figure 10 at room temperature.

[0042] Figure 15 is a graph showing data for the diffraction MTF at high temperature of the optical system of Figure 10.

[0043] Figure 16 is a graph showing data on the aberration characteristics of the optical system of Figure 10 at low temperatures.

[0044] Figure 17 is a graph showing data on the aberration characteristics of the optical system of Figure 10 at room temperature.

[0045] Figure 18 is a graph showing data on the aberration characteristics of the optical system of Figure 10 at high temperatures.

[0046] FIG. 19 is an example of a vehicle having an optical system according to an embodiment of the invention.

[0047] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0048] However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0049] In addition, terms used in this embodiment (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which this embodiment belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0050] Furthermore, the terms used in this embodiment are for the purpose of describing the embodiment and are not intended to limit the invention.

[0051] In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as "at least one of A and B and C (or more than one)," it may include one or more of all combinations that can be formed from A, B, and C.

[0052] In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the present embodiment. These terms are used merely to distinguish the components from other components and are not intended to limit the essence, order, or sequence of the components.

[0053] And, where it is stated that a component is 'connected', 'combined', or 'connected' to another component, this may include not only cases where the component is directly 'connected', 'combined', or 'connected' to the other component, but also cases where it is 'connected', 'combined', or 'connected' due to another component located between the component and the other component.

[0054] Furthermore, when described as being formed or placed "above" or "below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above" or "below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0055] In the description of the invention, "object side" may refer to a surface of the lens facing the object side with respect to the optical axis (OA), and "sensor side" may refer to a surface of the lens facing the imaging surface (image sensor) with respect to the optical axis. "Object side" may be the "object side," and "sensor side" may be the "image side." One surface of the lens being convex may refer to a convex shape in the optical axis or paraxial region, and one surface of the lens being concave may refer to a concave shape in the optical axis or paraxial region. The radius of curvature, center thickness, and optical axis spacing between lenses listed in the lens data table may refer to values ​​(unit, mm) in the optical axis. The vertical direction may refer to a direction perpendicular to the optical axis, and the end of the lens or lens surface may refer to the end of the effective area of ​​the lens through which 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 paraxial region refers to a very narrow region near the optical axis, and is a region where the distance of light rays from the optical axis (OA) is almost zero. Hereinafter, the term optical axis may include the center of each lens or a very narrow region near the optical axis.

[0056]

[0057] As shown in FIGS. 1 and FIGS. 10, the optical system (1000, 1100) according to the first and second embodiments of the present invention may include five or more lenses. The optical system (1000, 1100) and the camera module 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 as glass or plastic, and the coefficient of linear expansion of glass material is smaller than that of plastic material. Accordingly, glass lenses are employed to suppress changes in the focusing position due to temperature changes. Due to plastic lenses, good correction of various aberrations such as spherical aberration and chromatic aberration may be possible. In addition, since plastic lenses can provide aspherical lenses, distortion in the periphery can be minimized.

[0058] The optical system (1000, 1100) may include n lenses, the nth lens is the last lens adjacent to the image sensor (300), and the (n-1)th lens may be the lens closest to the last lens. n is an integer greater than or equal to 5, for example, 5 to 6.

[0059] The lens portion may include first to sixth lenses (101-106, 201-206) aligned along the optical axis from the object side toward the sensor side. Each lens (101-106, 201-206) may have an object side and a sensor side. The optical system may have more lenses having an aspherical sensor side and an aspherical object side than glass lenses. The optical system may have fewer lenses having a spherical sensor side and a spherical object side than lenses with aspherical surfaces on both sides. The optical system (1000, 1100) may have more aspherical lenses than spherical lenses.

[0060] Among the lenses of the optical system (1000, 1100), the maximum refractive index may be 1.7 or higher. The chromatic dispersion of incident light can be increased by the lens having the maximum refractive index, and the center thickness may be thinner than the edge thickness.

[0061]

[0062] The effective diameter may be the diameter of the effective area where effective light is incident from each lens. The effective diameter is the length in the direction (X,Y) perpendicular to the optical axis and is the average of the effective diameter of the object side and the effective diameter of the sensor side of each lens. "Diameter of the lens surface" may refer to the "effective diameter of the lens." "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 lens flange is not illustrated in FIG. 1 and FIG. 10, the flange may be a portion formed to protrude perpendicular to the optical axis from the side of the lens so that the lens can be coupled to the barrel. Effective light may not be incident on the flange. A spacer may be additionally placed between the flanges of different lenses to allow the lenses to be coupled to the barrel.

[0063] Each of the lenses (101-106, 201-206) may include an effective region and an ineffective region. The effective region may be an area through which light incident on each of the lenses passes. That is, the effective region may be defined as an effective area or effective mirror where the incident light is refracted to realize optical properties. The ineffective region may be positioned around the periphery of the effective region. The ineffective region may be an area where effective light is not incident from the plurality of lenses. That is, the ineffective region may be an area unrelated to optical properties. Additionally, the end of the ineffective region may be an area fixed to a lens barrel or the like that accommodates the lens.

[0064]

[0065] Within the optical system (1000, 1100), the Total Top Length (TTL) may be greater than 3 times, for example, greater than 3.5 times and less than or equal to 4 times Imgh. The Total Track Length (TTL) is the distance along the optical axis (OA) from the center of the object side of the first lens to the top plane of the image sensor (300). Imgh is the distance from the optical axis (OA) to the diagonal end of the image sensor (300) or half of the maximum diagonal length. Within the optical system (1000, 1100), the Effective Focal Length (EFL) may be provided as 2 mm or more and the Horizontal Field of View (HFOV) as less than 160 degrees, so that it can be provided as a standard optical system in a vehicle camera module. For example, the optical system and camera module according to the embodiment may be applied to a camera for an Advanced Driving Assistance System (ADAS) installed inside or outside a vehicle.

[0066] The optical system (1000, 1100) may have a TTL / Imgh condition of 3 or higher and 3.5 or higher, for example, 3.5 or higher and 4 or lower. By setting the TTL / Imgh value of the optical system (1000, 1100) to 3.5 or higher and 4 or lower, a vehicle lens optical system can be provided. Accordingly, the optical system (1000, 1100) can provide an image without exaggeration or distortion regarding the formed image.

[0067]

[0068] The effective diameter of at least one glass lens within the optical system (1000, 1100) may be larger than the length of the image sensor (300). The effective diameter is the diameter or length of the effective area where light is incident. The length of the image sensor (300) is the maximum length of the diagonal in the direction orthogonal to the optical axis (OA). There may be four or more lenses within the optical system (1000, 1100) having an effective diameter smaller than the length of the image sensor (300).

[0069]

[0070] The lens section may include plastic lenses. Accordingly, if plastic lenses are placed within the camera module, the weight of the camera module can be reduced. Furthermore, the plastic material is easy to polish and process, resistant to external impact, highly cost-competitive, and easy to secure. Additionally, various aberrations can be corrected by the plastic lenses, thereby preventing degradation of optical performance.

[0071] An embodiment of the invention includes a plastic lens within an optical system (1000, 1100), thereby reducing the weight of the camera module, providing a lower manufacturing cost, suppressing the degradation of optical properties due to temperature changes, allowing various types of plastic lenses to replace glass lenses, and facilitating the polishing and processing of lens surfaces such as aspherical or free-form surfaces.

[0072]

[0073] The effective diameter of the lens closest to the object side within the lens section may be larger than the effective diameter of the lens closest to the image sensor (300). 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 size of the effective diameters of each lens, the optical system (1000, 1100) can control the incident light to compensate for the degradation of optical characteristics due to resolution and temperature changes, improve chromatic aberration control characteristics, and improve the vignetting characteristics of the optical system (1000, 1100).

[0074] The lens portion may be disposed in a camera module having an inner barrel on one side or the entire inner surface of a lens barrel. The lens portion may be disposed in a camera module having a plurality of inner barrels around the circumference of different lenses of the lens barrel. The lens portion may be disposed 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 portion may be disposed in a camera module having a plurality of inner barrels each disposed between the outer surface of at least one or two or more lenses and the lens barrel. The lens portion may be disposed in a camera module in which the plurality of inner barrels have a material different from the material of the lens barrel.

[0075] Among the lenses constituting the lens section, at least some of the plastic lenses may be placed in an inner barrel positioned within the lens barrel. Through this, the optical system (1000, 1100) can maintain resolution in response to temperature changes. The lens section is positioned in a camera module having a different type of barrel to minimize decentering of lenses, such as plastic lenses, that expand in response to temperature changes. The lens barrel in which the lens section is positioned is provided with a plurality of inner barrels within the lens barrel, thereby maintaining the resolution of the optical system in response to temperature changes and suppressing deformation of the lenses.

[0076] In the lens portion, the minimum effective diameter may be in the range of 2mm to 5mm, and the maximum effective diameter may be in the range of 6mm to 8mm. Additionally, the optical system (1000, 1100) can improve resolution and chromatic aberration control characteristics by controlling incident light, and can improve the vignetting characteristics of the optical system (1000, 1100).

[0077] An optical system (1000, 1100) or a camera module may include an image sensor (300). The image sensor (300) may detect light and convert it into an electrical signal. The image sensor (300) may detect light that has passed through a lens section sequentially. The image sensor (300) may include a device capable of detecting incident light, such as a Charge Coupled Device (CCD) or a Complementary Metal Oxide Semiconductor (CMOS).

[0078] Here, the number of lenses having an effective diameter larger than the length of the image sensor (300) is 0 to 2, and the number of lenses having an effective diameter smaller than the length of the image sensor (300) may be 4 to 6.

[0079]

[0080] The optical system (1000, 1100) or camera module may include a filter (400). The filter (400) may be placed between the last lens and the image sensor (300). The filter (400) may be placed between the lens closest to the sensor side among the lenses of the lens unit and the image sensor (300). For example, the filter (400) may be placed between the nth lens and the image sensor (300).

[0081] The cover glass is placed between the filter (400) and the image sensor (300), protects the top of the image sensor (300), and can prevent a decrease in the reliability of the image sensor (300). The cover glass can be removed. The cover glass may be a protective glass.

[0082] The filter (400) may include an infrared filter or an infrared cut-off filter (IR cut-off). The filter (400) may pass light of a set wavelength band and filter light of a different wavelength band. If the filter (400) includes an infrared filter, it may block radiant heat emitted from external light from being transmitted to the image sensor (300). Additionally, the filter (400) may transmit visible light and reflect infrared light.

[0083] The optical system (1000, 1100) according to the embodiment may include an aperture (Stop). The aperture can control the amount of light incident on the optical system (1000, 1100).

[0084] In the optical system (1000, 1100) of the first and second embodiments, the sum of the refractive indices of the lenses in the lens section may be 9 or more, for example, in the range of 9 to 12, and the average refractive index may be in the range of 1.6 to 1.8. The sum of the Abbe numbers of each lens may be 200 or more, for example, in the range of 200 to 250, and the average Abbe number may be 50 or less, for example, in the range of 30 to 50. The sum of the center thicknesses of the entire lens may be 5 mm or more, for example, in the range of 7 mm to 10 mm, and the average of the center thicknesses may be in the range of 1.2 mm to 1.5 mm. The sum of the center spacings between the lenses on the optical axis (OA) may be 3 mm or more, for example, in the range of 3 mm to 5 mm, and may be smaller than the sum of the center thicknesses of the lenses. In addition, the average value of the effective diameter of each lens surface (S1-S12) of the lens section may be 3 mm or more, for example, in the range of 3 mm to 5 mm.

[0085]

[0086] In the optical system according to the first and second embodiments of the invention, the horizontal field of view may be 160 degrees or less, for example, in the range of 140 degrees to 160 degrees. The F number of the optical system or camera module may be 3.0 or less, for example, in the range of 2.0 to 3.0 or in the range of 2.5 to 3.0. The horizontal field of view (FOV_H) is a field 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 to provide a vehicle camera in which various aberrations are well corrected.

[0087] Since the optical system applied to a vehicle camera typically monitors road conditions, it may be designed based on the horizontal angle of view rather than the entire angle of view. The optical system according to the present embodiment is designed with a certain margin based on the inscribed circle of the image sensor. Optical performance can be guaranteed in the area that satisfies the range of the horizontal angle of view (FOV_H).

[0088] For driver monitoring, front / rear recording of the vehicle, or lane detection and detection of sudden objects around the vehicle during vehicle operation, the horizontal field of view may be greater than 140 degrees and less than 160 degrees, for example, in the range of 150 to 160 degrees. This horizontal field of view may be a preset angle for an Advanced Driver Assistance System (ADAS).

[0089] The optical system (1000, 1100) 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) toward the lenses. Hereinafter, the optical system according to the embodiment will be described in detail.

[0090]

[0091] We will now describe an optical system according to the first embodiment of the invention.

[0092] 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 the aspherical coefficients of aspherical lenses in the optical system of FIG. 1, FIG. 3 is a table showing the Sag values ​​of the lens surfaces of the first to sixth lenses in the optical system of FIG. 1, FIG. 4 is a graph showing data on the diffraction MTF (Modulation Transfer Function) of the optical system of FIG. 1 at low temperature, FIG. 5 is a graph showing data on the diffraction MTF of the optical system of FIG. 1 at room temperature, FIG. 6 is a graph showing data on the diffraction MTF of the optical system of FIG. 1 at high temperature, FIG. 7 is a graph showing data on the aberration characteristics of the optical system of FIG. 1 at low temperature, FIG. 8 is a graph showing data on the aberration characteristics of the optical system of FIG. 1 at room temperature, FIG. 9 is a graph showing data on the aberration characteristics of the optical system of FIG. 1 at high temperature.

[0093] Referring to FIG. 1, the optical system (1000) includes a lens portion, and the lens portion may include a first lens (101) to a sixth lens (106). The first to sixth lenses (101 to 106) may be arranged sequentially 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 sixth lens (106) and a filter (400) and be incident on an image sensor (300).

[0094] The first lens (101) may be positioned closest to the object side. The first lens (101) may be positioned furthest from the sensor side. The first lens (101) may have a negative (-) refractive power at the optical axis (OA). The first lens (101) may include plastic or glass material. For example, the first lens (101) may be provided with glass material.

[0095] With respect to the optical axis (OA), the first surface (S1) on the object side of the first lens (101) may be convex, and the fourth surface (S4) on the sensor side may be concave. The first lens (101) may have a meniscus shape that is concave toward the sensor side. The first lens (101) may have a meniscus shape that is convex toward the object side. The first lens (101) is made of glass material and may have a spherical surface. At least one or both of the first surface (S1) and the second surface (S2) may be spherical. At least one or both of the first surface (S1) and the second surface (S2) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0096]

[0097] The second lens (102) may be positioned second from the object side. The second lens (102) may be positioned fifth from the sensor side. The second lens (102) may be positioned between the first lens (101) and the third lens (103). The second lens (102) may have a negative (-) refractive power at the optical axis (OA). The second lens (102) may include plastic or glass material. For example, the second lens (102) may be provided with plastic material.

[0098] With respect to the optical axis (OA), the object-side third surface (S3) of the second lens (102) may be concave, and the sensor-side fourth surface (S4) may be convex. The second lens (102) may have a 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) is made of plastic material and may have an aspherical surface. At least one or both of the third surface (S3) and the fourth surface (S4) may be aspherical.

[0099] At least one or both of the third surface (S3) and the fourth surface (S4) may be provided without a threshold point from the optical axis (OA) to the end of the effective area.

[0100] The aperture (Stop) can be positioned around the perimeter of the sensor-side fourth surface (S4) of the second lens (102). The aperture (Stop) can be positioned around the perimeter of the object-side fifth surface (S5) of the third lens (103). The aperture can reduce TTL within the angle of view range, and the optical system can be miniaturized. Accordingly, a decrease in 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 TTL at a horizontal angle of view (FOV_H) of 140 to 160 degrees.

[0101]

[0102] The third lens (103) may be positioned as the third lens from the object side. The third lens (103) may be positioned as the fourth lens from the sensor side. The third lens (103) may be positioned between the second lens (102) and the fourth lens (104). The third lens (103) may have a positive (+) refractive power at the optical axis (OA). The third lens (103) may include plastic or glass material. For example, the third lens (103) may be provided with glass material.

[0103] With respect to the optical axis, the object-side fifth surface (S5) of the third lens (103) may be convex, and the sensor-side sixth surface (S6) may be convex. The third lens (103) may have a shape with both sides convex. The third lens (103) may be made of glass material 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 threshold point from the optical axis (OA) to the end of the effective area.

[0104]

[0105] The fourth lens (104) may be positioned as the fourth lens from the object side. The fourth lens (104) may be positioned as the third lens from the sensor side. The fourth lens (104) may be positioned between the third lens (103) and the fifth lens (105). The fourth lens (104) may have a negative (-) refractive power at the optical axis (OA). The fourth lens (104) may include plastic or glass material. For example, the fourth lens (104) may be provided with plastic material.

[0106] With respect to the optical axis, the object-side seventh surface (S7) of the fourth lens (104) may be convex, and the sensor-side eighth surface (S8) may be concave. The fourth lens (104) may have a meniscus shape with the sensor side being concave. The fourth lens (104) may have a meniscus shape with the object side being convex. The fourth lens (104) may be made of plastic material and may be aspherical. At least one or both of the seventh surface (S7) and the eighth surface (S8) may be aspherical. At least one or both of 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.

[0107]

[0108] The fifth lens (105) may be positioned as the fifth lens from the object side. The fifth lens (105) may be positioned as the second lens from the sensor side. The fifth lens (105) may be positioned between the fourth lens (104) and the sixth lens (106). The fifth lens (105) may have a positive (+) refractive power at the optical axis (OA). The fifth lens (105) may include plastic or glass material. For example, the fifth lens (105) may be provided with plastic material.

[0109] With respect to the optical axis, the object-side ninth surface (S9) of the fifth lens (105) may be convex, and the sensor-side tenth surface (S10) may be convex. The fifth lens (105) may have a shape with both sides convex. The fifth lens (105) may be made of plastic material and may be aspherical. At least one or both of the ninth surface (S9) and the tenth surface (S10) may be aspherical. At least one or both of the ninth surface (S9) and the tenth surface (S10) of the fifth lens (105) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0110]

[0111] The sixth lens (106) may be positioned as the sixth one from the object side. The sixth lens (106) may be positioned closest to the sensor side. The sixth lens (106) may have a negative (-) refractive power at the optical axis (OA). The fifth lens (105) may include plastic or glass material. For example, the sixth lens (106) may be provided with plastic material.

[0112] With respect to the optical axis, the object-side 11th surface (S11) of the 6th lens (106) may be concave, and the sensor-side 12th surface (S12) may be convex. The 6th lens (106) may have a meniscus shape with the sensor side being convex. The 6th lens (106) may have a meniscus shape with the object side being concave. The 6th lens (106) may be made of plastic material and may be aspherical. At least one or both of the 11th surface (S11) and the 12th surface (S12) may be aspherical. At least one or both of the 11th surface (S11) and the 12th surface (S12) of the 6th lens (106) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0113]

[0114] LensSurfaceRadiusThicknessndvdSemiApertureFocal length1S111.2871.4581.83542.7004.223-3.016S21.9461.8331.8462S1-19.9482.2811.64023.5001.800-619.428S2-21.9370.1 531.215StopStopinfinity0.3591.1503S16.4110.6911.67855.5001.2394.064S2-4.6551.0161.2504S14.3370.4001.68018.1001. 731-11.808S22.7240.3131.8275S13.2992.1281.53555.8002.1753.393S2-3.1600.2752.2696S1-2.0230.4501.68018.1002.282-6 .889S2-3.8410.0402.448Filterinfinity0.0862.533infinity0.0002.576Coverinfinity2.2182.595Imageinfinity-0.0023.087

[0115] Table 1 shows the surface number, radius of curvature, thickness of the center of each lens or distance between lens surfaces, index, nd, Abbe number (Abbe,vd), effective radius (Semi Aperture), and focal length of a lens according to the first embodiment of the present invention. At this time, the units of the radius of curvature and the thickness or distance may be mm.

[0116]

[0117] Item ValueItem ValueF2.356ET11.969ΣIndex10.048ET22.379ΣAbbe213.700ET30.400ΣCT7.408ET40.671ΣCG3.948ET50.700CA_max6.069ET60.999CA_min2.4 89F-number2.270CA_Aver4.051FOV_H150.800CT_max2.281ImgH3.64CT_min0.400SD5.312CT_Aver1.235TD11.396EPD1.035TTL13.999BFL2.643

[0118] Table 2 is for items of the mathematical formulas described above in the optical system (1000) of the embodiment, and is for the TTL (Total track length) (mm), BFL (Back focal length), effective focal length (F) (mm), ImgH (mm), effective diameter (CA) (mm), thickness (mm), TTL (mm), optical axis distance from the first plane (S1) to the twelfth plane (S12) TD (mm), optical axis distance from the aperture (Stop) to the twelfth plane (S12) SD (mm), sum of refractive indices, sum of Abbe numbers, sum of thicknesses (mm), sum of spacing between adjacent lenses, effective diameter characteristics, diagonal angle of view (FOV_D) (Degree), vertical angle of view (FOV_V) (Degree), horizontal angle of view (FOV_H) (Degree), edge thickness (ET), F number, etc. of the optical system (1000).

[0119] The center thickness of the first to sixth lenses (101 to 106) is denoted as CT1 to CT6, the edge thickness of the end of the effective area of ​​each lens is denoted as ET1 to ET6, the center gap between two adjacent lenses is denoted as CG1 to CG5, and the edge gap between the edges of each lens is denoted as EG1 to EG5. BFL (Back focal length) is the optical axis distance from the image sensor (300) 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 (101) to the top surface of the image sensor (300).

[0120] As shown in FIG. 2, among the lenses of the lens portion of the first embodiment, the lens surfaces of the second lens (102) and the fourth to sixth lenses (104 to 106) may include an aspherical surface having a 30th-order aspherical coefficient. For example, the second lens (102) and the fourth to sixth lenses (104 to 106) may include a lens surface having a 30th-order aspherical coefficient. As described above, an aspherical surface having a 30th-order aspherical coefficient (a non-zero value) can significantly change the shape of the aspherical surface in the periphery, and thus can effectively correct the optical performance of the periphery of the field of view (FOV).

[0121]

[0122] When compared by the absolute values ​​of the radius of curvature of each lens, the radius of curvature of the fourth surface (S4) of the second lens (102) at the optical axis (OA) may be the maximum among the lenses, and the radius of curvature of the second surface (S2) of the first lens (101) may be the minimum among the lenses. The difference between the maximum radius of curvature and the minimum radius of curvature may be 10 times or more, for example, in the range of 10 to 15 times.

[0123] In temperature-compensated designs that must maintain resolution despite temperature variations ranging from -40 to 85 degrees, a larger radius of curvature can be advantageous. Aluminum barrels may be used for lens barrels in temperature-compensated designs. However, due to the large manufacturing tolerances of aluminum barrels, the optical axes between lenses become significantly misaligned when assembled. Therefore, designing a large radius of curvature can reduce sensitivity to manufacturing tolerances.

[0124]

[0125] The absolute value of the radius of curvature of the first surface (S1) of the first lens (101) may be greater than the absolute value of the radius of curvature of the second surface (S2). The absolute value of the radius of curvature of the third surface (S3) of the second lens (102) may be smaller than the absolute value of the radius of curvature of the fourth surface (S4). The absolute value of the radius of curvature of the fifth surface (S5) of the third lens (103) may be greater than the absolute value of the radius of curvature of the sixth surface (S6). The absolute value of the radius of curvature of the seventh surface (S7) of the fourth lens (104) may be greater than the absolute value of the radius of curvature of the eighth surface (S8). The absolute value of the radius of curvature of the ninth surface (S9) of the fifth lens (105) may be greater than the absolute value of the radius of curvature of the tenth surface (S10). The absolute value of the radius of curvature of the 11th surface (S11) of the 6th lens (106) may be smaller than the absolute value of the radius of curvature of the 12th surface (S12).

[0126] The ratio of the radius of curvature of each lens can satisfy the following conditions.

[0127] Condition 1: 5.5 < |L1R1 / L1R2| < 6

[0128] Condition 2: 0.5 < |L2R1 / L2R2| < 1

[0129] Condition 3: 1 < |L3R1 / L3R2| < 1.5

[0130] Condition 4: 1.5 < |L4R1 / L4R2| < 2

[0131] Condition 5: 1 < |L5R1 / L5R2| < 1.5

[0132] Condition 6: 0.5 < |L6R1 / L6R2| < 1

[0133]

[0134] When describing the center thickness of the lenses based on the optical axis, the center thickness (CT2) of the second lens (102) is the largest among the lenses, and the center thickness (CT4) of the fourth lens (104) is the smallest among the lenses. The difference between the maximum center thickness and the minimum center thickness among the lenses may be in the range of 1.5 mm or more and 2 mm or less.

[0135] The relationship between the center thickness (CT) of the lenses is designed by considering the refractive power and shape of each lens, and if conditions 1 to 6 below are satisfied, an appropriate light path can be established and optical performance improved.

[0136] In the optical system (1000) according to the first embodiment, the center thickness (CT2) of the second lens (102) positioned on the object side of the aperture (STOP) may be the largest, and the center thickness (CT4) of the fourth lens (104) positioned adjacent to the sensor side of the aperture (STOP) may be the smallest. The second lens (102) positioned adjacent to the aperture (STOP) has the smallest absolute value of refractive power among lenses with negative (-) refractive power, and is designed to have the largest center thickness so that light incident on the second lens (102) can be refracted weakly and aberrations can be reduced. The fourth lens (104) is designed to have the smallest center thickness (CT4) so ​​that the optical path can be improved and the overall size and weight of the optical system can be reduced.

[0137] The center thickness (CT5) of the fifth lens (105) may be larger than the center thickness (CT1) of the first lens (101). By establishing a relationship between the first lens (101) and the fifth lens (105) that have similar absolute values ​​of refractive power, the optical path can be set so that light incident on the optical system is spread out and then incident on the image sensor (300), thereby improving aberrations.

[0138] The center thickness of each lens can satisfy any one of the following conditions.

[0139] Condition 1: CT2, CT5 > CT1 > CT3, CT4, CT6

[0140] Condition 2: CT2 > CT1, CT3, CT4, CT5, CT6

[0141] Condition 3: CT1, CT2, CT5 > CT3 > CT4, CT6

[0142] Condition 4: CT1, CT2, CT3, CT5, CT6 > CT4

[0143] Condition 5: CT2 > CT5 > CT1, CT3, CT4, CT6

[0144] Condition 6: CT1, CT2, CT3, CT5 > CT6 > CT4

[0145]

[0146] To describe the center spacing (CG) between the lenses, the center spacing (CG1) between the first lens (101) and the second lens (102) may be maximum, and the center spacing (CG5) between the fifth and sixth lenses (105, 106) may be minimum. The difference between the maximum center spacing and the minimum center spacing among the spaced-out lens spacings may be 1 mm or more, for example, in the range of 1.5 mm to 2 mm.

[0147] The relationship between the center distances (CG) of the lenses is designed by considering the refractive power and shape of each lens, and if conditions 1 to 5 below are satisfied, an appropriate light path can be established and optical performance can be improved.

[0148] The center spacing between each lens can satisfy the following conditions.

[0149] Condition 1: CG1 > CG2, CG3, CG4, CG5

[0150] Condition 2: CG1, CG3 > CG2 > CG4, CG5

[0151] Condition 3: CG1 > CG3 > CG2, CG4, CG5

[0152] Condition 4: CG1, CG2, CG3 > CG4 > CG5

[0153] Condition 5: CG1, CG2, CG3, CG4 > CG5

[0154]

[0155] To explain the effective diameter, the effective diameter of the first lens (101) is maximum, and the lens having the maximum effective diameter may be a lens made of glass material. Here, the effective diameter is the average of the effective diameter of the object side of each lens and the effective diameter of the sensor side. The lens surface having the maximum effective diameter may be the first surface (S1) of the first lens (101).

[0156] The effective diameter of the third lens (103) may be the minimum within the lens portion. The lens surface having the minimum effective diameter may be the fourth surface (S4) of the second lens (102).

[0157] The effective diameter of each lens can satisfy any one of the following conditions.

[0158] Condition 1: CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6

[0159] Condition 2: CA_L1, CA_L4, CA_L5, CA_L6 > CA_L2 > CA_L3

[0160] Condition 3: CA_L1, CA_L2, CA_L4, CA_L5, CA_L6 > CA_L3

[0161] Condition 4: CA_L1, CA_L5, CA_L6 > CA_L4 > CA_L2, CA_L3

[0162] Condition 5: CA_L1, CA_L6 > CA_L5 > CA_L2, CA_L3, CA_L4

[0163] Condition 6: CA_L1 > CA_L6 > CA_L2, CA_L3, CA_L4, CA_L5

[0164]

[0165] Regarding the refractive index, the refractive index of the first lens (101) is the maximum among the lenses and may be greater than 1.7, for example, greater than 1.8. The fifth lens (105) may have the minimum refractive index among the lenses. For example, the refractive index of the fifth lens (105) may be the minimum among the lenses and may be less than 1.7, for example, less than 1.6. The difference between the maximum refractive index and the minimum refractive index may be 0.2 or greater.

[0166] The refractive index of each lens can satisfy any one of the following conditions.

[0167] Condition 1: n1 > n2, n3, n4, n5, n6

[0168] Condition 2: n1, n3, n4, n6 > n2 > n5

[0169] Condition 3: n1, n4, n6 > n3 > n2, n5

[0170] Condition 4: n1 > n4 = n6 > n2, n3, n5

[0171] Condition 5: n1, n2, n3, n4, n6 > n5

[0172]

[0173] When comparing the Abbe numbers, the Abbe number of the fourth lens (104) is the maximum among the lenses and may be 60 or more. The Abbe number of the fifth lens (105) is the minimum among the lenses and may be 25 or less. The difference between the maximum Abbe number and the minimum Abbe number may be 50 or more.

[0174] The Abbe number of each lens can satisfy any one of the following conditions.

[0175] Condition 1: v3, v5 > v1 > v2, v4, v6

[0176] Condition 2: v1, v3, v5 > v2 > v4, v6

[0177] Condition 3: v5 > v3 > v1, v2, v4, v6

[0178] Condition 4: v1, v2, v3, v5 > v4 = v6

[0179] Condition 5: v5 > v1, v2, v3, v4, v6

[0180]

[0181] The focal lengths (F3, F5) of the third and fifth lenses (103, 105) may have a positive (+) sign. The third and fifth lenses (103, 105) may have a positive (+) refractive power. The focal lengths (F1, F2, F4, F6) of the first, second, fourth, and sixth lenses (101, 102, 104, 106) may have a negative (-) sign. The first, second, fourth, and sixth lenses (101, 102, 104, 106) may have a negative (-) refractive power.

[0182]

[0183] When comparing the absolute values ​​of the focal lengths, the focal length of the second lens (102) is the largest among the lenses and may be 600 or more and 650 or less. Among the lenses, the second lens (102), which is made of plastic, may have the largest focal length and the smallest refractive power. The focal length of the first lens (101) is the smallest among the lenses, and the absolute value of the focal length of the first lens (101) may be 2 or more and 5 or less. Among the lenses, the sixth lens (106), which is made of plastic, may have the smallest focal length and the largest refractive power.

[0184] Among the lenses, the lens having the minimum focal length may be the first lens (101). The difference between the maximum focal length and the minimum focal length may be 600 or more or 650 or more. Accordingly, the optical system may have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. within the angle of view range set in the optical system, and may have good optical performance at the periphery of the angle of view.

[0185] The absolute value of the focal length of each lens can satisfy any one of the following conditions.

[0186] Condition 1: |f2|, |f3|, |f4|, |f5|, |f5| > |f1|

[0187] Condition 2: |f2| > |f1|, |f3|, |f4|, |f5|, |f6|

[0188] Condition 3: |f2|, |f4|, |f6| > |f3| > |f1|, |f5|

[0189] Condition 4: |f2| > |f4| > |f1|, |f3|, |f5|, |f6|

[0190] Condition 5: |f2|, |f3|, |f4|, |f6| > |f5| > |f1|

[0191] Condition 6: |f2|, |f4| > |f6| > |f1|, |f3|, |f5|

[0192]

[0193] 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 1 to 1.5 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 to 1.5 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 minimum at the center and maximum at the edge, and the maximum thickness is in the range of 1.5 to 2 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 3 to 3.5 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 to 2.5 times the minimum thickness.

[0194] The thickness of each lens can satisfy any one of the following conditions.

[0195] Condition 1: 0.5 < CT1 / ET1 < 1, 1 < ET1 / CT1 < 1.5

[0196] Condition 2: 0.5 < CT2 / ET2 < 1, 1 < ET2 / CT2 < 1.5

[0197] Condition 3: 1.5 < CT3 / ET3 < 2, 0.5 < ET3 / CT3 < 1

[0198] Condition 4: 0.5 < CT4 / ET4 < 1, 1.5 < ET4 / CT4 < 2

[0199] Condition 5: 3 < CT5 / ET5 < 3.5, 0.1 < ET5 / CT5 < 0.5

[0200] Condition 6: 0.1 < CT6 / ET6 < 0.5, 2 < ET6 / CT6 < 2.5

[0201] Condition 7: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0202]

[0203] Among the gaps (G1-G5) between the lenses, the first gap (G1) between the first and second lenses (101, 102) may have a maximum center and a minimum edge. The second gap (G2) between the second and third lenses (102, 103) may have a minimum center and a maximum edge. The third gap (G3) between the third and fourth lenses (103, 104) may have a maximum edge and a minimum center. The fourth gap (G4) between the fourth and fifth lenses (104, 105) may have a minimum edge and a maximum center. The fifth gap (G5) between the fifth and sixth lenses (105, 106) may have a minimum edge and a maximum center.

[0204]

[0205] FIGS. 4 to 6 are graphs showing the modulation transfer function (MTF) of the diffraction at low, room, and high temperatures in the optical system of FIG. 1, and graphs showing the modulation of luminance according to spatial frequency. As shown in FIGS. 4 to 6, in the first embodiment of the invention, the deviation of the MTF from low or high temperatures relative to room temperature may be less than 5%, i.e., 3% or less.

[0206] FIGS. 7 to 9 are graphs showing the aberration characteristics of the optical system of FIG. 1 at low, room, and high temperatures. The aberration graphs of FIGS. 7 to 9 show the longitudinal spherical aberration, astigmatic field curves, and distortion measured from left to right. In FIGS. 7 to 9, the X-axis may represent focal length (mm) and distortion (%), and the Y-axis may represent the height of the image. Additionally, the graph for longitudinal spherical aberration is for light in the wavelength bands of approximately 435 nm, approximately 486 nm, approximately 546 nm, approximately 587 nm, and approximately 656 nm, and the graphs for astigmatic field curves and distortion are for light in the wavelength band of approximately 546 nm. In the aberration diagrams of FIGS. 7 to 9, it can be interpreted that the closer the curves at low temperature, room temperature, and high temperature are to the Y-axis, the better the aberration correction function is. In the optical system (1000) according to the first embodiment, it can be seen that the measured values ​​are adjacent to the Y-axis in almost all areas. That is, the optical system (1000) according to the first embodiment has improved resolution and can have good optical performance not only in the center of the field of view (FOV) but also in the periphery. Here, the low temperature is -20 degrees or lower, for example, in the range of -20 to -40 degrees; the room temperature is in the range of 22 degrees ± 5 degrees or 18 degrees to 27 degrees; and the high temperature is 85 degrees or higher, for example, in the range of 85 degrees to 105 degrees. Accordingly, it can be seen that the decrease in luminance modulation from low temperature to high temperature in FIGS. 7 to 9 is less than 10%, for example, 5% or less, or hardly changes.

[0207] Table 3 shows the changes in optical properties, such as EFL, BFL, and F-number, at low, room, and high temperatures in the optical system according to the first embodiment. It can be seen that the rate of change in optical properties at low temperatures relative to room temperature is 5% or less, for example, 3% or less. Additionally, Table 3 compares the Center MTF in the optical system according to the first embodiment, and the Center MTF at low and high temperatures can satisfy a range of 3% or less, for example, 2% or less, relative to room temperature.

[0208] Room Temperature Low Temperature High Temperature Low Temperature / Room Temperature High Temperature / Room Temperature EFL(F) 2.3554mm 2.3501mm 2.3608mm 99.77% 100.22% BFL 2.62mm 2.639mm 2.644mm 100.72% 100.91% F-number 2.27 2.27 2.232 100% 98.32% Center MTF 84% 85% 83%--

[0209] 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.

[0210] We will now describe an optical system according to the second embodiment of the invention.

[0211] FIG. 10 is a side cross-sectional view of an optical system according to a second embodiment and a camera module having the same, FIG. 11 is a table showing the aspherical coefficients of aspherical lenses in the optical system of FIG. 10, FIG. 12 is a table showing the Sag values ​​of the lens surfaces of the first to sixth lenses in the optical system of FIG. 10, FIG. 13 is a graph showing data on the diffraction MTF (Modulation Transfer Function) of the optical system of FIG. 10 at low temperature, FIG. 14 is a graph showing data on the diffraction MTF of the optical system of FIG. 10 at room temperature, FIG. 15 is a graph showing data on the diffraction MTF of the optical system of FIG. 10 at high temperature, FIG. 16 is a graph showing data on the aberration characteristics of the optical system of FIG. 10 at low temperature, FIG. 17 is a graph showing data on the aberration characteristics of the optical system of FIG. 10 at room temperature, and FIG. 18 is a graph showing data on the aberration characteristics of the optical system of FIG. 10 at high temperature.

[0212] Referring to FIG. 10, the optical system (1100) includes a lens portion, and the lens portion may include a first lens (201) to a sixth lens (206). The first to sixth lenses (201 to 206) may be arranged sequentially 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 sixth lens (206) and a filter (400) and be incident on an image sensor (300).

[0213] The first lens (201) may be positioned closest to the object side. The first lens (201) may be positioned furthest from the sensor side. The first lens (201) may have a negative (-) refractive power at the optical axis (OA). The first lens (201) may include plastic or glass material. For example, the first lens (201) may be provided with glass material.

[0214] With respect to the optical axis (OA), the first surface (S1) on the object side of the first lens (201) may be convex, and the fourth surface (S4) on the sensor side may be concave. The first lens (201) may have a meniscus shape that is concave toward the sensor side. The first lens (201) may have a meniscus shape that is convex toward the object side. The first lens (201) is made of glass material and may have a spherical surface. At least one or both of the first surface (S1) and the second surface (S2) may be spherical. At least one or both of the first surface (S1) and the second surface (S2) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0215]

[0216] The second lens (202) may be positioned second from the object side. The second lens (202) may be positioned fifth from the sensor side. The second lens (202) may be positioned between the first lens (201) and the third lens (203). The second lens (202) may have a negative (-) refractive power at the optical axis (OA). The second lens (202) may include plastic or glass material. For example, the second lens (202) may be provided with plastic material.

[0217] With respect to the optical axis (OA), the object-side third surface (S3) of the second lens (202) may be concave, and the sensor-side fourth surface (S4) may be convex. The second lens (202) may have a meniscus shape that is convex toward the sensor side. The second lens (202) may have a meniscus shape that is concave toward the object side. The second lens (202) is made of plastic material and may have an aspherical surface. At least one or both of the third surface (S3) and the fourth surface (S4) may be aspherical.

[0218] At least one or both of the third surface (S3) and the fourth surface (S4) may be provided without a threshold point from the optical axis (OA) to the end of the effective area.

[0219] The aperture (Stop) can be positioned around the perimeter of the sensor-side fourth surface (S4) of the second lens (202). The aperture (Stop) can be positioned around the perimeter of the object-side fifth surface (S5) of the third lens (203). The aperture can reduce TTL within the angle of view range, and the optical system can be miniaturized. Accordingly, a decrease in 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 TTL at a horizontal angle of view (FOV_H) of 140 to 160 degrees.

[0220]

[0221]

[0222] The third lens (203) may be positioned as the third lens from the object side. The third lens (203) may be positioned as the fourth lens from the sensor side. The third lens (203) may be positioned between the second lens (202) and the fourth lens (204). The third lens (203) may have a positive (+) refractive power at the optical axis (OA). The third lens (203) may include plastic or glass material. For example, the third lens (203) may be provided with glass material.

[0223] With respect to the optical axis, the object-side fifth surface (S5) of the third lens (203) may be convex, and the sensor-side sixth surface (S6) may be convex. The third lens (203) may have a shape with both sides convex. The third lens (203) may be made of glass material 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 threshold point from the optical axis (OA) to the end of the effective area.

[0224]

[0225] The fourth lens (204) may be positioned as the fourth lens from the object side. The fourth lens (204) may be positioned as the third lens from the sensor side. The fourth lens (204) may be positioned between the third lens (203) and the fifth lens (205). The fourth lens (204) may have a negative (-) refractive power at the optical axis (OA). The fourth lens (204) may include plastic or glass material. For example, the fourth lens (204) may be provided with plastic material.

[0226] With respect to the optical axis, the object-side seventh surface (S7) of the fourth lens (204) may be convex, and the sensor-side eighth surface (S8) may be concave. The fourth lens (204) may have a meniscus shape with the sensor side being concave. The fourth lens (204) may have a meniscus shape with the object side being convex. The fourth lens (204) may be made of plastic material and may be aspherical. At least one or both of the seventh surface (S7) and the eighth surface (S8) may be aspherical. At least one or both of 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.

[0227]

[0228] The fifth lens (205) may be positioned as the fifth lens from the object side. The fifth lens (205) may be positioned as the second lens from the sensor side. The fifth lens (205) may be positioned between the fourth lens (204) and the sixth lens (206). The fifth lens (205) may have a positive (+) refractive power at the optical axis (OA). The fifth lens (205) may include plastic or glass material. For example, the fifth lens (205) may be provided with plastic material.

[0229] With respect to the optical axis, the object-side ninth surface (S9) of the fifth lens (205) may be convex, and the sensor-side tenth surface (S10) may be convex. The fifth lens (205) may have a shape with both sides convex. The fifth lens (205) may be made of plastic material and may be aspherical. At least one or both of the ninth surface (S9) and the tenth surface (S10) may be aspherical. At least one or both of the ninth surface (S9) and the tenth surface (S10) of the fifth lens (205) may be provided without a threshold point from the optical axis (OA) to the end of the effective area.

[0230]

[0231] The sixth lens (206) may be positioned sixth from the object side. The sixth lens (206) may be positioned closest to the sensor side. The sixth lens (206) may have a positive (+) refractive power at the optical axis (OA). The fifth lens (205) may include plastic or glass material. For example, the sixth lens (206) may be provided with plastic material.

[0232] With respect to the optical axis, the object-side 11th surface (S11) of the 6th lens (206) may be concave, and the sensor-side 12th surface (S12) may be convex. The 6th lens (206) may have a meniscus shape with the sensor side being convex. The 6th lens (206) may have a meniscus shape with the object side being concave. The 6th lens (206) may be made of plastic material and may be aspherical. At least one or both of the 11th surface (S11) and the 12th surface (S12) may be aspherical. At least one or both of the 11th surface (S11) and the 12th surface (S12) of the 6th lens (206) may be provided without a critical point from the optical axis (OA) to the end of the effective area.

[0233]

[0234] LensSurfaceRadiusThicknessndvdSemiApertureFocal length1S117.7962.3141.64057.7005.419-3.673S21.9721.660 1.868 2S1-79.1122.2991.64023.5001.700-3015.584S2-83.4010.144 1.099 StopStopinfinity0.534 1.050 3S17.5580.6811.69050.0001.1323.956S2-4.2280.650 1.200 4S17.5290.4841.70018.1001.556-6.514S22.7400.076 1.741 5S13.2401.6961.53555.8001.7993.482S2-3.6191.811 2.029 6S1-1.4620.5701.68018.1002.3416519.426S2-1.6940.040 2.572 Filterinfinity0.300 2.783 infinity0.040 2.825 Coverinfinity0.899 2.834 Imageinfinity0.001 3.100

[0235] Table 4 shows the surface number, radius of curvature, thickness of the center of each lens or distance between lens surfaces, index, nd, Abbe number (Abbe,vd), effective radius (Semi Aperture), and focal length of the lens according to the second embodiment of the present invention. At this time, the units of the radius of curvature and the thickness or distance may be mm.

[0236] Item ValueItem ValueF2.398ET12.811ΣIndex9.885ET22.389ΣAbbe223.200ET30.418ΣCT8.044ET40.853ΣCG4.876ET50.687CA_max7.287ET60.683CA_min2.33 2F-number2.170CA_Aver4.076FOV_H152.000CT_max2.314ImgH3.64CT_min0.484SD6.009CT_Aver1.341TD12.960EPD1.103TTL14.200BFL1.280

[0237] Table 5 is for the items of the mathematical formulas described above in the optical system (1100) of the embodiment, and is for the TTL (Total track length) (mm), BFL (Back focal length), effective focal length (F) (mm), ImgH (mm), effective diameter (CA) (mm), thickness (mm), TTL (mm), optical axis distance from the first plane (S1) to the twelfth plane (S12) TD (mm), optical axis distance from the aperture (Stop) to the twelfth plane (S12) SD (mm), sum of refractive indices, sum of Abbe numbers, sum of thicknesses (mm), sum of spacing between adjacent lenses, effective diameter characteristics, diagonal angle of view (FOV_D) (Degree), vertical angle of view (FOV_V) (Degree), horizontal angle of view (FOV_H) (Degree), edge thickness (ET), F number, etc.

[0238] The center thickness of the first to sixth lenses (201 to 206) is denoted as CT1 to CT6, the edge thickness of the end of the effective area of ​​each lens is denoted as ET1 to ET6, the center gap between two adjacent lenses is denoted as CG1 to CG5, and the edge gap between the edges of each lens is denoted as EG1 to EG5. BFL (Back focal length) is the optical axis distance from the image sensor (300) 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 top surface of the image sensor (300).

[0239] As shown in FIG. 11, among the lenses of the lens portion of the second embodiment, the lens surfaces of the second lens (202) and the fourth to sixth lenses (204 to 206) may include an aspherical surface having a 30th-order aspherical coefficient. For example, the second lens (202) and the fourth to sixth lenses (204 to 206) may include a lens surface having a 30th-order aspherical coefficient. As described above, an aspherical surface having a 30th-order aspherical coefficient (a non-zero value) can significantly change the shape of the aspherical surface in the periphery, and thus can effectively correct the optical performance of the periphery of the field of view (FOV).

[0240]

[0241] When compared by the absolute values ​​of the radius of curvature of each lens, the radius of curvature of the fourth surface (S4) of the second lens (202) at the optical axis (OA) may be the maximum among the lenses, and the radius of curvature of the eleventh surface (S11) of the sixth lens (206) may be the minimum among the lenses. The difference between the maximum radius of curvature and the minimum radius of curvature may be 50 times or more, for example, in the range of 50 to 60 times.

[0242] In temperature-compensated designs that must maintain resolution despite temperature variations ranging from -40 to 85 degrees, a larger radius of curvature can be advantageous. Aluminum barrels may be used for lens barrels in temperature-compensated designs. However, due to the large manufacturing tolerances of aluminum barrels, the optical axes between lenses become significantly misaligned when assembled. Therefore, designing a large radius of curvature can reduce sensitivity to manufacturing tolerances.

[0243]

[0244] The absolute value of the radius of curvature of the first surface (S1) of the first lens (201) may be greater than the absolute value of the radius of curvature of the second surface (S2). The absolute value of the radius of curvature of the third surface (S3) of the second lens (202) may be smaller than the absolute value of the radius of curvature of the fourth surface (S4). The absolute value of the radius of curvature of the fifth surface (S5) of the third lens (203) may be greater than the absolute value of the radius of curvature of the sixth surface (S6). The absolute value of the radius of curvature of the seventh surface (S7) of the fourth lens (204) may be greater than the absolute value of the radius of curvature of the eighth surface (S8). The absolute value of the radius of curvature of the ninth surface (S9) of the fifth lens (205) may be smaller than the absolute value of the radius of curvature of the tenth surface (S10). The absolute value of the radius of curvature of the 11th surface (S11) of the 6th lens (206) may be smaller than the absolute value of the radius of curvature of the 12th surface (S12).

[0245] The ratio of the radius of curvature of each lens can satisfy the following conditions.

[0246] Condition 1: 9 < |L1R1 / L1R2| < 9.5

[0247] Condition 2: 0.5 < |L2R1 / L2R2| < 1

[0248] Condition 3: 1.5 < |L3R1 / L3R2| < 2

[0249] Condition 4: 2.5 < |L4R1 / L4R2| < 3

[0250] Condition 5: 0.5 < |L5R1 / L5R2| < 1

[0251] Condition 6: 0.5 < |L6R1 / L6R2| < 1

[0252]

[0253] When describing the center thickness of the lenses based on the optical axis, the center thickness (CT1) of the first lens (201) is the maximum among the lenses, and the center thickness (CT4) of the fourth lens (204) is the minimum among the lenses. The difference between the maximum center thickness and the minimum center thickness among the lenses may be in the range of 1.5 mm or more and 2 mm or less.

[0254] The relationship between the center thickness (CT) of the lenses is designed by considering the refractive power and shape of each lens, and if conditions 1 to 6 below are satisfied, an appropriate light path can be established and optical performance improved.

[0255] The thickness (CT5) of the fifth lens (205) may be greater than the thickness (CT1) of the first lens (201). By establishing a relationship between the first lens (201) and the fifth lens (205) that have similar absolute values ​​of refractive power, the optical path can be set so that light incident on the optical system is spread out and then incident on the image sensor (300), thereby improving aberrations.

[0256] The center thickness of each lens can satisfy any one of the following conditions.

[0257] Condition 1: CT1 > CT2, CT3, CT4, CT5, CT6

[0258] Condition 2: CT1 > CT2 > CT3, CT4, CT5, CT6

[0259] Condition 3: CT1, CT2, CT5 > CT3 > CT4, CT6

[0260] Condition 4: CT1, CT2, CT3, CT5, CT6 > CT4

[0261] Condition 5: CT1, CT2 > CT5 > CT3, CT4, CT6

[0262] Condition 6: CT1, CT2, CT3, CT5 > CT6 > CT4

[0263]

[0264] To describe the center spacing (CG) between the lenses, the center spacing (CG5) between the fifth lens (205) and the sixth lens (206) may be maximum, and the center spacing (CG4) between the fourth and fifth lenses (204, 205) may be minimum. The difference between the maximum center spacing and the minimum center spacing among the spaced-out lens spacings may be 1 mm or more, for example, in the range of 1.5 mm to 2 mm.

[0265] The relationship between the center distances (CG) of the lenses is designed by considering the refractive power and shape of each lens, and if conditions 1 to 5 below are satisfied, an appropriate light path can be established and optical performance can be improved.

[0266] The center spacing between each lens can satisfy the following conditions.

[0267] Condition 1: CG5 > CG1 > CG2, CG3, CG4

[0268] Condition 2: CG1, CG5 > CG2 > CG3, CG4

[0269] Condition 3: CG1, CG2, CG5 > CG3 > CG4

[0270] Condition 4: CG1, CG2, CG3, CG5 > CG4

[0271] Condition 5: CG5 > CG1, CG2, CG3, CG4

[0272]

[0273] To explain the effective diameter, the effective diameter of the first lens (201) is maximum, and the lens having the maximum effective diameter may be a lens made of glass material. Here, the effective diameter is the average of the effective diameter of the object side of each lens and the effective diameter of the sensor side. The lens surface having the maximum effective diameter may be the first surface (S1) of the first lens (201).

[0274] The effective diameter of the third lens (203) may be the minimum within the lens portion. The lens surface having the minimum effective diameter may be the fourth surface (S4) of the second lens (202).

[0275] The effective diameter of each lens can satisfy any one of the following conditions.

[0276] Condition 1: CA_L1 > CA_L2, CA_L3, CA_L4, CA_L5, CA_L6

[0277] Condition 2: CA_L1, CA_L4, CA_L5, CA_L6 > CA_L2 > CA_L3

[0278] Condition 3: CA_L1, CA_L2, CA_L4, CA_L5, CA_L6 > CA_L3

[0279] Condition 4: CA_L1, CA_L5, CA_L6 > CA_L4 > CA_L2, CA_L3

[0280] Condition 5: CA_L1, CA_L6 > CA_L5 > CA_L2, CA_L3, CA_L4

[0281] Condition 6: CA_L1 > CA_L6 > CA_L2, CA_L3, CA_L4, CA_L5

[0282]

[0283] Regarding the refractive index, the refractive index of the fourth lens (204) is the maximum among the lenses and may be greater than 1.6, for example, greater than 1.65. The fifth lens (205) may have the minimum refractive index among the lenses. For example, the refractive index of the fifth lens (205) may be the minimum among the lenses and may be less than 1.7, for example, less than 1.6. The difference between the maximum refractive index and the minimum refractive index may be 0.15 or greater.

[0284] The refractive index of each lens can satisfy any one of the following conditions.

[0285] Condition 1: n3, n4, n6 > n1 = n2 > n5

[0286] Condition 2: n4 > n3 > n1, n2, n5, n6

[0287] Condition 3: n4 > n1, n2, n3, n5, n6

[0288] Condition 4: n1, n2, n3, n4, n6 > n5

[0289] Condition 5: n3, n4 > n6 > n1, n2, n5

[0290]

[0291] When comparing the Abbe numbers, the Abbe number of the first lens (201) is the maximum among the lenses and may be 50 or more. The Abbe number of the sixth lens (206) is the minimum 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.

[0292] The Abbe number of each lens can satisfy any one of the following conditions.

[0293] Condition 1: v1 > v2, v3, v4, v5, v6

[0294] Condition 2: v1, v3, v5 > v2 > v4, v6

[0295] Condition 3: v1, v5 > v3 > v2, v4, v6

[0296] Condition 4: v1, v2, v3, v5 > v4 = v6

[0297] Condition 5: v1 > v5 > v2, v3, v4, v6

[0298]

[0299] The focal lengths (F3, F5, F6) of the 3rd, 5th, and 6th lenses (203, 205, 206) may have a positive (+) sign. The 3rd, 5th, and 6th lenses (203, 205, 206) may have a positive (+) refractive power. The focal lengths (F1, F2, F4) of the 1st, 2nd, and 4th lenses (201, 202, 204) may have a negative (-) sign. The 1st, 2nd, and 4th lenses (201, 202, 204) may have a negative (-) refractive power.

[0300]

[0301] When comparing the absolute values ​​of the focal lengths, the focal length of the 6th lens (206) is the largest among the lenses and may be 6000 or more to 7000 or less. Among the lenses, the 6th lens (206), which is made of plastic, may have the largest focal length and the smallest refractive power. The focal length of the 5th lens (205) is the smallest among the lenses, and the absolute value of the focal length of the 5th lens (205) may be 3 or more to 5 or less. Among the lenses, the 5th lens (205), which is made of plastic, may have the smallest focal length and the largest refractive power.

[0302] Among the lenses, the lens having the minimum focal length may be the first lens (201). The difference between the maximum focal length and the minimum focal length may be 6000 or more or 6500 or more. Accordingly, the optical system may have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. within the angle of view range set in the optical system, and may have good optical performance at the periphery of the angle of view.

[0303] The absolute value of the focal length of each lens can satisfy any one of the following conditions.

[0304] Condition 1: |f2|, |f3|, |f4|, |f5| > |f1| > |f5|

[0305] Condition 2: |f6| > |f2| > |f1|, |f3|, |f4|, |f5|

[0306] Condition 3: |f2|, |f4|, |f6| > |f3| > |f1|, |f5|

[0307] Condition 4: |f2|, |f6| > |f4| > |f1|, |f3|, |f5|

[0308] Condition 5: |f1|, |f2|, |f3|, |f4|, |f6| > |f5|

[0309] Condition 6: |f6| > |f1|, |f2|, |f3|, |f4|, |f5|

[0310]

[0311] 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 1 to 1.5 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 to 1.5 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 minimum at the center and maximum at the edge, and the maximum thickness is in the range of 1.5 to 2 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 1 to 1.5 times the minimum thickness.

[0312] The thickness of each lens can satisfy any one of the following conditions.

[0313] Condition 1: 0.5 < CT1 / ET1 < 1, 1 < ET1 / CT1 < 1.5

[0314] Condition 2: 0.5 < CT2 / ET2 < 1, 1 < ET2 / CT2 < 1.5

[0315] Condition 3: 1.5 < CT3 / ET3 < 2, 0.5 < ET3 / CT3 < 1

[0316] Condition 4: 0.5 < CT4 / ET4 < 1, 1.5 < ET4 / CT4 < 2

[0317] Condition 5: 2 < CT5 / ET5 < 2.5, 0.1 < ET5 / CT5 < 0.5

[0318] Condition 6: 0.5 < CT6 / ET6 < 1, 1 < ET6 / CT6 < 1.5

[0319] Condition 7: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0320]

[0321] Among the gaps (G1-G5) between the lenses, the first gap (G1) between the first and second lenses (201, 202) may have a maximum center and a minimum edge. The second gap (G2) between the second and third lenses (202, 203) may have a minimum center and a maximum edge. The third gap (G3) between the third and fourth lenses (203, 204) may have a maximum edge and a minimum center. The fourth gap (G4) between the fourth and fifth lenses (204, 205) may have a minimum edge and a maximum center. The fifth gap (G5) between the fifth and sixth lenses (205, 206) may have a minimum edge and a maximum center.

[0322]

[0323] FIGS. 13 to 15 are graphs showing the modulation transfer function (MTF) of the diffraction at low, room, and high temperatures in the optical system of FIG. 10, and graphs showing the modulation of luminance according to spatial frequency. As shown in FIGS. 13 to 15, in the second embodiment of the invention, the deviation of the MTF from low or high temperatures relative to room temperature may be less than 5%, i.e., 3% or less.

[0324] FIGS. 16 to 18 are graphs showing the aberration characteristics of the optical system of FIG. 10 at low, room, and high temperatures. The aberration graphs of FIGS. 16 to 18 show the longitudinal spherical aberration, astigmatic field curves, and distortion measured from left to right. In FIGS. 16 to 18, the X-axis may represent focal length (mm) and distortion (%), and the Y-axis may represent the height of the image. Additionally, the graph for longitudinal spherical aberration is for light in the wavelength bands of approximately 435 nm, approximately 486 nm, approximately 546 nm, approximately 587 nm, and approximately 656 nm, and the graphs for astigmatic field curves and distortion are for light in the wavelength band of approximately 546 nm. In the aberration diagrams of FIGS. 16 to 18, it can be interpreted that the aberration correction function is better as the curves at low temperature, room temperature, and high temperature are closer to the Y-axis. In the optical system (1100) according to the second embodiment, it can be seen that the measured values ​​are adjacent to the Y-axis in almost all areas. That is, the optical system (1100) according to the second embodiment has improved resolution and can have good optical performance not only in the center of the field of view (FOV) but also in the periphery. Here, the low temperature is -20 degrees or lower, for example, in the range of -20 to -40 degrees; the room temperature is 22 degrees ± 5 degrees or 18 degrees to 27 degrees; and the high temperature is 85 degrees or higher, for example, in the range of 85 degrees to 105 degrees. Accordingly, it can be seen that the decrease in luminance modulation from low temperature to high temperature in FIGS. 16 to 18 is less than 10%, for example, 5% or less, or hardly changes.

[0325] Table 6 shows the changes in optical properties, such as EFL, BFL, and F-number, at low, room, and high temperatures in the optical system according to the second embodiment. It can be seen that the rate of change in optical properties at low temperatures relative to room temperature is 5% or less, for example, 3% or less. Additionally, Table 6 compares the Center MTF in the optical system according to the second embodiment, and the Center MTF at low and high temperatures can satisfy a range of 3% or less, for example, 2% or less, relative to room temperature.

[0326] Room Temperature Low Temperature High Temperature Low Temperature / Room Temperature High Temperature / Room Temperature EFL(F) 2.398mm 2.3877mm 2.4079mm 99.57% 100.41% BFL 1.28mm 1.277mm 1.2827mm 99.76% 100.21% F-number 2.17 2.16 2.18 99.53% 100.46% Center MTF 84.4% 84% 83.3%--

[0327] 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.

[0328] The optical system (1000, 1100) according to the first and second embodiments disclosed above may satisfy at least one or two of the mathematical formulas described below. Accordingly, the optical system (1000, 1100) according to the first and second embodiments may have improved optical characteristics. For example, if the optical system (1000, 1100) satisfies at least one mathematical formula, the optical system (1000, 1100) can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and may have good optical performance not only at the center of the field of view (FOV) but also at the periphery. In addition, the optical system (1000, 1100) may have improved resolution. Furthermore, regarding the meaning of the thickness of the lens at the optical axis (OA) and the spacing of adjacent lenses at the optical axis (OA) described in the mathematical formulas, one may refer to the first and second embodiments disclosed above.

[0329]

[0330] The optical system (1000, 1100) according to the first and second embodiments disclosed above may satisfy at least one or two of the mathematical formulas described below. Accordingly, the optical system (1000, 1100) according to the first and second embodiments may have improved optical characteristics. For example, if the optical system (1000, 1100) satisfies at least one mathematical formula, the optical system (1000, 1100) can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and may have good optical performance not only at the center of the field of view (FOV) but also at the periphery. In addition, the optical system (1000, 1100) may have improved resolution. Furthermore, regarding the meaning of the thickness of the lens at the optical axis (OA) and the spacing of adjacent lenses at the optical axis (OA) described in the mathematical formulas, one may refer to the first and second embodiments disclosed above.

[0331]

[0332] [Mathematical Formula 1]

[0333] 0.1 < F / TTL < 0.2

[0334] In Equation 1, F represents the effective focal length of the optical system, and TTL (Total track length) represents the distance (mm) along the optical axis (OA) from the vertex of the first surface (S1) of the first lens (101, 201) to the top surface of the image sensor (300). Accordingly, an optical system for a driver assistance system can be provided. When the optical system (1000, 1100) according to the embodiment satisfies Equation 1, the optical system (1000, 1100) can have an appropriate focal length within the set TTL range and can form an image while maintaining an appropriate focal length even as the temperature changes from low to high temperature. If it is below the lower limit of Equation 1, it is necessary to increase the refractive power of the lenses, making it difficult to correct spherical aberration or distortion aberration; if it exceeds the upper limit of Equation 1, the effective diameter or TTL of the lenses becomes longer, which may cause a problem where the imaging lens system becomes larger. In the first and second embodiments, mathematical formula 1 can preferably satisfy 0.16 < F / TTL < 0.17.

[0335]

[0336] [Mathematical Formula 2]

[0337] 3 < TTL / ImgH < 4

[0338] In Equation 2, TTL (Total track length) refers to the distance (mm) along the optical axis (OA) from the vertex of the first surface (S1) of the first lens (101, 201) to the top surface of the image sensor (300), and ImgH refers to half of the maximum diagonal length of the image sensor (300). When Equation 2 is satisfied, the optical system (1000, 1100) can have a TTL for application to the vehicle image sensor (300), thereby providing improved image quality. If it is below the lower limit of Equation 2, it is necessary to increase the refractive power of the lenses, making it difficult to correct spherical aberration or distortion aberration; if it exceeds the upper limit of Equation 2, the effective aperture or TTL of the lenses becomes longer, which may cause a problem where the imaging lens system becomes larger. In the first and second embodiments, mathematical formula 2 can preferably satisfy 3.5 < TTL / ImgH < 4.

[0339]

[0340] [Mathematical Formula 3]

[0341] 1 < |F1| / F < 2

[0342] In Equation 3, F1 is the focal length of the first lens (101, 201), and F is the effective focal length of the optical system. If Equation 3 is satisfied, the optical system (1000, 1100) can have a set angle of view and an appropriate focal length, and an optical system for vehicles can be provided. Additionally, the angle of view can be set large within an appropriate TTL range through the first lens (101, 201) having negative (-) refractive power. If it is below the lower limit of Equation 3, the effective aperture or TTL of the lenses becomes longer, which may cause a problem where the imaging lens system becomes large. If it exceeds the upper limit of Equation 3, the influence of the first lens (101, 201) in the entire optical system decreases, and it becomes necessary to increase the refractive power of the lenses, which makes it difficult to correct spherical aberration or distortion aberration. In the first and second embodiments, Equation 3 is preferably 1.2 < |F1| / F < 1.6 can be satisfied.

[0343]

[0344] [Mathematical Formula 4]

[0345] 20 < |F2| / F < 1300

[0346] In Equation 4, F2 is the focal length of the second lens (102, 202), and F is the effective focal length of the optical system. If Equation 4 is satisfied, the optical system (1000, 1100) can have a set angle of view and an appropriate focal length, and an optical system for vehicles can be provided. If it is below the lower limit of Equation 4, the effective aperture or TTL of the lenses becomes longer, which may cause a problem where the imaging lens system becomes large. If it exceeds the upper limit of Equation 4, the influence of the second lens (102, 202) in the entire optical system decreases, and it becomes necessary to increase the refractive power of the lenses, which makes it difficult to correct spherical aberration or distortion aberration. In the first embodiment, Equation 4 preferably satisfies 250 < |F2| / F < 270. In the second embodiment, Equation 4 preferably satisfies 1200 < |F2| / F < 1300 can be satisfied.

[0347]

[0348] [Mathematical Formula 5]

[0349] 1.5 < F3 / F < 2

[0350] In Equation 5, F1 is the focal length of the third lens (103, 203), and F is the effective focal length of the optical system. When Equation 5 is satisfied, the optical system (1000, 1100) can have a set angle of view and an appropriate focal length, and a vehicle optical system can be provided. In addition, the angle of view can be set large within an appropriate TTL range through the third lens (103, 203). If it is below the lower limit of Equation 5, the effective aperture or TTL of the lenses becomes longer, which may cause a problem where the imaging lens system becomes large. If it exceeds the upper limit of Equation 5, the influence of the third lens (103, 203) in the entire optical system decreases, and it is necessary to increase the refractive power of the lenses, which makes it difficult to correct spherical aberration or distortion aberration. In the first and second embodiments, Equation 5 can preferably satisfy 1.6 < F3 / F < 1.8.

[0351]

[0352] [Mathematical Formula 6]

[0353] 1.6 < n1 < 1.9

[0354] In Equation 6, n1 is the refractive index of the first lens (101, 201). When Equation 6 is satisfied, the first lens (101, 201) positioned closest to the object side has a high refractive index, thereby minimizing chromatic aberration. In the first and second embodiments, Equation 6 can preferably satisfy 1.63 < n1 < 1.85.

[0355]

[0356] [Mathematical Formula 7]

[0357] 48 < v3 < 60

[0358] In Equation 7, v3 is the Abbe number of the third lens (103, 203). If Equation 7 is satisfied, chromatic aberration can be minimized by using a low-dispersion material for the third lens (103, 203) positioned adjacent to the aperture (STOP). In the first and second embodiments, Equation 7 can preferably satisfy 49 < v3 < 56.

[0359]

[0360] [Mathematical Formula 8]

[0361] 15 < v4 ​​< 20

[0362] In Equation 8, v4 is the Abbe number of the fourth lens (104, 204). If Equation 8 is satisfied, chromatic aberration can be minimized by using a low-dispersion material for the fourth lens (104, 204) positioned adjacent to the aperture (STOP). In the first and second embodiments, Equation 8 can preferably satisfy 17 < v4 ​​< 19.

[0363]

[0364] [Mathematical Formula 9]

[0365] 0.5 < L2R1 / L2R2 < 1

[0366] In Equation 9, L2R1 is the radius of curvature of the object side (third surface (S3)) of the second lens (102, 202), and L2R2 is the radius of curvature of the sensor side (fourth surface (S4)) of the second lens (102, 202). When Equation 9 is satisfied, the lens surface of the second lens (102, 202) can be designed to be close to a flat plane so that the focal length has a large value. In the first and second embodiments, Equation 9 can preferably satisfy 0.8 < L2R1 / L2R2 < 1.

[0367]

[0368] [Mathematical Formula 10]

[0369] 0.5 < L4R2 / L5R1 < 1

[0370] In Equation 10, L4R2 is the radius of curvature of the sensor side (eighth surface (S8)) of the fourth lens (104,204), and L5R1 is the radius of curvature of the object side (ninth surface (S9)) of the fifth lens (105,205). When Equation 10 is satisfied, the radius of curvature of the mutually facing surfaces of the fourth lens (104,204) and the fifth lens (105,205) is designed to be similar, thereby improving the chromatic aberration correction performance of the fourth lens (104,204) and allowing the refractive power of the fifth lens (105,205) to be set significantly. In the first and second embodiments, Equation 10 can preferably satisfy 0.7 < L4R2 / L5R1 < 0.9.

[0371]

[0372] [Mathematical Formula 11]

[0373] 1 < L5R2 / L6R1 < 3

[0374] In Equation 11, L5R2 is the radius of curvature of the sensor side (10th surface (S10)) of the 5th lens (105,205), and L6R1 is the radius of curvature of the object side (11th surface (S11)) of the 6th lens (106,206). When Equation 11 is satisfied, the radius of curvature of the mutually facing surfaces of the 5th lens (105,205) and the 6th lens (106,206) is designed to be similar, thereby allowing the refractive power of the 5th lens (105,205) and the 6th lens (106,206) to be set to be large. In the 1st and 2nd embodiments, Equation 11 can preferably satisfy 1.3 < L5R2 / L6R1 < 2.5.

[0375]

[0376] [Mathematical Formula 12]

[0377] 0.1 < CA_min / CA_max < 0.5

[0378] In Equation 12, CA_min represents the minimum effective diameter among the object sides and sensor sides of the lenses, and CA_max represents the maximum effective diameter among the object sides and sensor sides of the lenses. When Equation 12 is satisfied, the optical system can set a size for a slim and compact structure while maintaining optical performance. In the first and second embodiments, Equation 12 can preferably satisfy 0.3 < CA_min / CA_max < 0.5.

[0379]

[0380] [Mathematical Formula 14]

[0381] 1 < CA_L1S1 / F < 8

[0382] In Equation 14, CA_L1S1 is the effective aperture of the object side (first surface (S1)) of the first lens (101, 201), and F is the effective focal length of the optical system. If the value is less than the lower limit of Equation 14, there is a problem that the effective aperture of the lens placed closest to the object side of the optical system (1000, 1100) becomes excessively large, and consequently, the TTL becomes long. If the value exceeds the upper limit of Equation 14, there is a problem that the angle of view becomes excessively large compared to what is satisfied by the optical system (1000, 1100). In the first embodiment, Equation 14 can preferably satisfy 2.5 < CA_L1S1 / F < 2. In the second embodiment, Equation 14 can preferably satisfy 7 < CA_L1S1 / F < 8.

[0383]

[0384] [Mathematical Formula 15]

[0385] 2 < F / EPD < 3

[0386] In Equation 15, F is the effective focal length of the optical system, and EPD represents the diameter of the entrance pupil (effective aperture). When Equation 15 is satisfied, an image with brightness suitable for driver monitoring can be provided, and a large amount of light can be received by the image sensor. In the first and second embodiments, Equation 15 can preferably satisfy 2 < F / EPD < 2.5.

[0387]

[0388] [Mathematical Formula 16]

[0389] 0.01 < BFL / TTL < 0.2

[0390] In Equation 16, BFL represents the optical axis distance from the image sensor (300) to the center of the sensor side of the last lens, and TTL (Total track length) represents the distance (mm) along the optical axis (OA) from the vertex of the first surface (S1) of the first lens (101, 201) to the top surface of the image sensor (300). When Equation 16 is satisfied, the optical system (1000, 1100) can have a set angle of view and an appropriate focal length, and an optical system for vehicles can be provided. In addition, the optical system (1000, 1100) can minimize the gap between the last lens and the image sensor (300), thereby having good optical characteristics at the periphery of the angle of view (FOV). In the first and second embodiments, Equation 16 can preferably satisfy 0.08 < BFL / TTL < 0.19.

[0391]

[0392] [Mathematical Formula 17]

[0393] 1 < CT_Max / CG_Max < 1.5

[0394] In Equation 17, CT_Max is the maximum center thickness among the lenses, and CG_Max is the maximum distance between adjacent lenses. If Equation 17 is satisfied, the optical system can have good optical performance at the focal length at the set angle of view and can reduce TTL. In the first and second embodiments, Equation 17 can preferably satisfy 1 < CT_Max / CG_Max < 1.3.

[0395]

[0396] [Mathematical Formula 18]

[0397] 0.5 < ΣCG / ΣCT < 1

[0398] In Equation 18, ΣCT is the sum of the center thicknesses of the lenses, and ΣCG is the sum of the spacings between adjacent lenses. If Equation 18 is satisfied, the optical system can have good optical performance at a focal length at a set angle of view and can reduce TTL. In the first and second embodiments, Equation 18 can preferably satisfy 0.5 < ΣCG / ΣCT < 0.7.

[0399]

[0400] [Mathematical Formula 19]

[0401] 0.1 < CG1 / ΣCG < 0.5

[0402] In Equation 19, CG1 is the center distance between the first lens (101, 201) and the second lens (102, 202), and ΣCG is the sum of the distances between adjacent lenses. When Equation 19 is satisfied, the light emitted from the first lens (101, 201), which has a significant influence on the entire optical system, establishes a light path incident on the remaining lenses, and the optical system can have good optical performance at the set angle of view and focal length. In the first and second embodiments, Equation 19 preferably satisfies 0.3 < CG1 / ΣCG < 0.5.

[0403]

[0404] [Mathematical Formula 20]

[0405] 0.1 < CG1 / ΣCT < 0.5

[0406] In Equation 20, CG1 is the center distance between the first lens (101, 201) and the second lens (102, 202), and ΣCT is the sum of the center thicknesses of the lenses. When Equation 20 is satisfied, the light emitted from the first lens (101, 201), which has a large influence on the entire optical system, establishes a light path incident on the remaining lenses, and the optical system can have good optical performance at the set angle of view and focal length. In the first and second embodiments, Equation 20 can preferably satisfy 0.1 < CG1 / ΣCT < 0.3.

[0407]

[0408] [Mathematical Formula 21]

[0409] 140 < FOV_H < 160

[0410] In mathematical formula 21, FOV_H represents the horizontal angle of view (Degree) of the optical system (1000, 1100) and can provide an angle of view suitable for a vehicle optical system. In the first and second embodiments, preferably, 148 < FOV_H < 153 can be satisfied.

[0411]

[0412] [Mathematical Formula 22]

[0413] 1 < TTL / CA_max < 3

[0414] In Equation 22, TTL (Total track length) represents the distance (mm) along the optical axis (OA) from the vertex of the first surface (S1) of the first lens (101, 201) to the top surface of the image sensor (300), and CA_max represents the maximum effective diameter among the object sides and sensor sides of the lenses. When Equation 22 is satisfied, the optical system can maintain good optical performance and set a size for a slim and compact structure. In the first and second embodiments, Equation 22 preferably satisfies 1.5 < TTL / CA_max < 2.5.

[0415]

[0416] [Mathematical Formula 23]

[0417] 5 < TTL / CA_min < 7

[0418] In Equation 23, TTL (Total track length) represents the distance (mm) along the optical axis (OA) from the vertex of the first surface (S1) of the first lens (101, 201) to the top surface of the image sensor (300), and CA_min represents the minimum effective diameter among the object sides and sensor sides of the lenses. When Equation 23 is satisfied, the optical system can maintain good optical performance and set a size for a slim and compact structure. In the first and second embodiments, Equation 23 preferably satisfies 5.5 < TTL / CA_min < 6.5.

[0419]

[0420] [Mathematical Formula 24]

[0421] 12 < TTL < 15

[0422] In Equation 24, TTL (Total track length) refers to the distance (mm) along the optical axis (OA) from the center of the first surface (S1) of the first lens (101, 201) to the top surface of the image sensor (300). If Equation 24 is satisfied, a suitable automotive optical system can be provided. In the first and second embodiments, Equation 24 can preferably satisfy 13 < TTL < 15.

[0423]

[0424] [Mathematical Formula 25]

[0425] 3 < ImgH < 4

[0426] In mathematical formula 25, ImgH means half of the maximum diagonal length of the image sensor (300). Mathematical formula 25 can set the diagonal size of the image sensor (300) and can provide an optical system having a sensor size for a vehicle. In the first and second embodiments, mathematical formula 25 can preferably satisfy 3.5 < ImgH < 4.

[0427]

[0428] [Mathematical Formula 26]

[0429] 1 < BFL < 3

[0430] In Equation 26, BFL is the optical axis distance from the image sensor (300) to the center of the sensor side of the last lens. If Equation 26 is satisfied, installation space for the filter (400) and cover glass can be secured, and the assembly of components and coupling reliability can be improved through the gap between the image sensor (300) and the last lens. If BFL is less than the range of Equation 26, some light proceeding to the image sensor may not be transmitted to the image sensor, which may cause a decrease in resolution. If BFL exceeds the range of Equation 26, stray light may be introduced, which may degrade the aberration characteristics of the optical system. In the first and second embodiments, Equation 26 preferably satisfies 1 < BFL < 2.7.

[0431]

[0432] [Mathematical Formula 27]

[0433] 2 < F < 3

[0434] Equation 27 can set the total focal length (F) to suit the automotive optical system. In the first and second embodiments, Equation 27 can satisfy 2 < F < 2.5.

[0435]

[0436] [Mathematical Formula 28]

[0437]

[0438] In Equation 28, Z represents Sag, which can mean the distance in the direction of the optical axis from any position on the aspherical surface to the vertex of the aspherical surface. Y represents the distance in the direction perpendicular to the optical axis from any position on the aspherical surface to the optical axis. c can represent the curvature of the lens, and K can represent the conic constant. Additionally, A, B, C, D, E, and F can represent the aspheric constants.

[0439]

[0440] The optical system (1000, 1100) according to the first and second embodiments may satisfy at least one or two of the mathematical formulas 1 to 28. In this case, the optical system (1000, 1100) may have improved optical characteristics. Specifically, when the optical system (1000, 1100) satisfies at least one or two of the mathematical formulas 1 to 28, the optical system (1000, 1100) may have improved resolution and may improve aberration and distortion characteristics. In addition, the optical system (1000, 1100) may secure a Back Focal Length (BFL) for applying a vehicle image sensor (300), compensate for the degradation of optical characteristics due to temperature changes, and minimize the gap between the last lens and the image sensor (300), thereby having good optical performance in the center and periphery of the field of view (FOV).

[0441]

[0442] Table 7 shows the result values ​​for the above-described Equations 1 to 27 in the optical system (1000, 1100) of the embodiment. Referring to Table 7, it can be seen that the optical system (1000, 1100) satisfies at least one, two or more, or three or more of Equations 1 to 27. Specifically, it can be seen that the optical system (1000, 1100) according to the embodiment satisfies all of Equations 1 to 27. Accordingly, the optical system (1000, 1100) can have good optical performance and excellent optical characteristics at the center and periphery of the field of view (FOV).

[0443] Mathematical formula: Example 1, Example 2 10.1 < F / TTL < 0.2 0.168 < TTL / ImgH < 43.842 3.901 < |F1| / F < 21.280 1.532 < |F2| / F < 1300 262.949 < F3 / F < 21.725 1.650 < n1 < 1.9 1.835 < v3 < 60 55.500 < v4 < 20 18.100 < v4 < 20 18.100 < v4 < 20 0.5 < L2R1 / L2R2 < 10.909 0.949 < L4R2 / L5R1 < 10.826 0.846 < L5R2 / L6R1 < 31.562 2.476 < CA_min / CA_max < 0.5 0.410 < CA_min / CA_avg < 10.614 0.572 < CA_L1S1 / F < 81.793 7.422 < F / EPD < 32.276 2.174 < 0.01 < BFL / TTL < 0.2 0.189 < CT_Max / CG_Max < 1.5 1.244 < 0.5 < ΣCG / ΣCT < 10.533 0.606 < 0.1 < CG1 / ΣCG < 0.5 0.464 < 0 < CG1 / ΣCT < 0.5 0.247 < 0 < CG1 / ΣCT < 0.5 0.225 < 140 < FOV_H < 160 150.800 < 152.000 < TTL / CA_max < 32.306 1.949 < 5 < TTL / CA_min < 75.624 6.090 < 12 < TTL < 15 13.999 < 14.200 < 3 < ImgH < 43.6 43.6 < 42 < 1 < BFL < 32.6 431.280 < 2 < F < 32.356 2.398

[0444] FIG. 19 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. 19, a vehicle camera system according to an embodiment of the invention includes an image generation unit (11), a first information generation unit (12), a second information generation unit (21, 22, 23, 24, 25, 26), and a control unit (14). The image generation unit (11) may include at least one camera module (31) disposed in the vehicle and may generate a front image of the vehicle or an interior image of the vehicle by photographing the front of the vehicle and / or the driver. The image generation unit (11) may generate an image of the vehicle's surroundings by photographing the vehicle's surroundings in one or more directions as well as the front of the vehicle using the camera module (31). Here, the front image and the surrounding image may be digital images and may include color images, black and white images, and infrared images. Additionally, the front image and the surrounding image may include still images and video images. The image generation unit (11) provides the driver image, the front image, and the surrounding image to the control unit (14). Subsequently, the first information generation unit (12) may include at least one radar and / or camera placed on the vehicle and generates first detection information by detecting the front of the vehicle. Specifically, the first information generation unit (12) is placed on the vehicle and generates first detection information by detecting the position and speed of vehicles located in front of the vehicle, the presence and location of pedestrians, etc. Using the first detection information generated by the first information generation unit (12), control can be made to maintain a constant distance between the vehicle and the vehicle in front, and the stability of vehicle operation can be enhanced in specific cases that are pre-set, such as when the driver intends to change the driving lane of the vehicle or when reverse parking. The first information generation unit (12) provides the first detection information to the control unit (14). The second information generation unit (21, 22, 23, 24, 25, 26) generates second detection information by detecting each side of the vehicle based on the front image generated by the image generation unit (11) and the first detection information generated by the first information generation unit (12).Specifically, the second information generating unit (21, 22, 23, 24, 25, 26) may include at least one radar or / and camera positioned on the vehicle and may detect the position and speed of vehicles located on the side of the vehicle or capture images. Here, the second information generating unit (21, 22, 23, 24, 25, 26) may be positioned at both front corners, side mirrors, and at the rear center and both rear corners of the vehicle, respectively.

[0445] At least one information generating unit among such vehicle camera systems may be equipped with an optical system and a camera module having the same as described in the embodiment disclosed above, and may provide to or process information obtained through the front, rear, each side, or corner area of ​​the vehicle to protect the vehicle and objects from autonomous driving or surrounding safety.

[0446] The optical system of the camera module according to an embodiment of the invention can be mounted in multiple units within a vehicle to comply with safety regulations, enhance autonomous driving functions, and increase convenience. Furthermore, the optical system of the camera module is applied within the vehicle as a component for control, such as a Lane Keeping Assistance System (LKAS), Lane Departure Warning System (LDWS), and Driver Monitoring System (DMS). Such a vehicle camera module can achieve stable optical performance even with changes in ambient temperature and provides a cost-competitive module, thereby ensuring the reliability of vehicle components.

[0447]

[0448] 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 only one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment may be combined or modified and implemented in other embodiments by a person skilled in the art to which the embodiments belong. Therefore, details regarding such combinations and modifications should be interpreted as being included within the scope of the present invention.

[0449] Furthermore, although the invention has been described above with reference to embodiments, this is merely illustrative and does not limit the invention. Those skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments may be modified and implemented. Differences related to such modifications and applications should be interpreted as being included within the scope of the invention as defined in the appended claims.

Claims

1. Includes first to sixth lenses arranged along the optical axis, and The first lens above has a negative (-) refractive power, and The above third lens has a positive (+) refractive power, and The above-mentioned fourth lens has a negative (-) refractive power, and The above-mentioned fifth lens has a positive (+) refractive power, and The above-mentioned sixth lens has a negative (-) refractive power, and An optical system in which the thickness of the fifth lens at the above optical axis is greater than the thickness of the first lens.

2. In Paragraph 1, An optical system in which the distance between the second lens and the third lens on the above optical axis is smaller than the distance between the third lens and the fourth lens.

3. In Paragraph 1, The optical system in which the fourth lens on the above optical axis has a meniscus shape that is convex toward the object.

4. In Paragraph 1, An optical system in which the second lens has the largest thickness among the first to sixth lenses on the above optical axis.

5. In Paragraph 1, An optical system in which the thickness of the fourth lens among the first to sixth lenses is the smallest on the optical axis.

6. In Paragraph 1, The above second lens is an optical system having negative (-) refractive power.

7. In any one of paragraphs 1 through 6, An optical system satisfying the following condition. <Condition> 0.5 < L2R1 / L2R2 < 1 (In the above conditional equation, L2R1 is the radius of curvature of the object side of the second lens, and L2R2 is the radius of curvature of the sensor side of the second lens.) 8. In any one of paragraphs 1 through 6, An optical system satisfying the following condition. <Condition> 3 < TTL / ImgH < 4 (In the above conditional equation, TTL is the distance from the object side of the first lens to the top plane of the image sensor along the optical axis, and ImgH is half the maximum diagonal length of the image sensor.) 9. Includes first to sixth lenses arranged along the optical axis, and The first lens above has a negative (-) refractive power, and The above third lens has a positive (+) refractive power, and The above-mentioned fifth lens has a positive (+) refractive power, and The above-mentioned sixth lens has a negative (-) refractive power, and The thickness of the second lens on the above optical axis is greater than the thickness of the first lens, and An optical system in which the thickness of the fifth lens at the above optical axis is greater than the thickness of the first lens.

10. In Paragraph 9, In the above optical axis, the fifth lens has a shape with both sides convex, and The optical system in which the sixth lens at the above optical axis has a meniscus shape that is concave toward the object.

Images