KR20240028846A - Optical system and camera module - Google Patents

Abstract

The optical system disclosed in the embodiment of the invention includes first to seventh lenses aligned along the optical axis from the object side to the sensor side, the refractive power of the first lens is negative, and the synthesis of the second to seventh lenses. The refractive power is positive, the refractive power of the seventh lens is negative, the first lens is a spherical lens with a maximum central thickness, and the central thickness of the first lens is the second lens at the center of the object-side surface of the fifth lens. 6 It can be larger than the optical axis distance to the center of the sensor side of the lens.

Description

Optical system and camera module {OPTICAL SYSTEM AND CAMERA MODULE}

The embodiment relates to an optical system for improved optical performance and a camera module including the same.

ADAS (Advanced Driving Assistance System) is an advanced driver assistance system to assist the driver in driving. It senses the situation ahead, judges the situation based on the sensed results, and controls the vehicle's behavior based on the situation judgment. It consists of For example, ADAS sensor devices detect vehicles in front and recognize lanes. Afterwards, when the target lane, target speed, and target ahead are determined, the vehicle's ESC (Electrical Stability Control), EMS (Engine Management System), and MDPS (Motor Driven Power Steering) are controlled. Typically, ADAS can be implemented as an automatic parking system, a low-speed city driving assistance system, and a blind spot warning system.

Sensor devices for detecting the situation ahead in ADAS include GPS sensors, laser scanners, front radar, and Lidar, and the most representative ones are cameras for photographing the front, rear, and sides of the vehicle.

These cameras can be placed outside or inside a vehicle to detect the surrounding conditions of the vehicle. Additionally, the camera may be placed inside the vehicle to detect the situation of the driver and passengers. For example, the camera can photograph the driver from a location adjacent to the driver and detect the driver's health status, drowsiness, drinking, etc. In addition, the camera can photograph the passenger at a location adjacent to the passenger, detect whether the passenger is sleeping, state of health, etc., and provide information about the passenger to the driver.

In particular, the most important element in obtaining an image from a camera is the imaging lens that forms the image. Recently, interest in high performance such as high image quality and high resolution has been increasing, and research is being conducted on optical systems that include multiple lenses to realize this. However, there is a problem that the characteristics of the optical system change when the camera is exposed to harsh environments, such as high temperature, low temperature, moisture, high humidity, etc., outside or inside the vehicle. In this case, the camera has a problem in that it is difficult to uniformly derive excellent optical and aberration characteristics.

Therefore, a new optical system and camera that can solve the above-mentioned problems are required.

The embodiment seeks to provide an optical system and camera module with improved optical characteristics.

The embodiment seeks to provide an optical system and a camera module with excellent optical performance in low to high temperature environments.

Embodiments seek to provide an optical system and a camera module that can prevent or minimize changes in optical properties in various temperature ranges.

The optical system according to an embodiment of the invention includes first to seventh lenses aligned along the optical axis from the object side to the sensor side, the refractive power of the first lens is negative, and the composite of the second to seventh lenses The refractive power is positive, the refractive power of the seventh lens is negative, the first lens is a spherical lens with a maximum central thickness, and the central thickness of the first lens is the second lens at the center of the object-side surface of the fifth lens. 6 It can be larger than the optical axis distance to the center of the sensor side of the lens.

According to an embodiment of the invention, the center spacing between the i-th lens and the i+1 lens is CGi, the center thickness of the i-th lens is CTi, and the value of CTi/CGi may be maximum when i is 1.

According to an embodiment of the invention, the value of CTi/CGi may be minimum when i is 3.

According to an embodiment of the invention, the effective diameter of the first lens is CA1, the effective diameter of the second lens is CA2, the effective diameter of the third lens is CA3, the effective diameter of the fourth lens is CA4, and the equation: CA1 < CA2 < CA3 < CA4 can be satisfied.

According to an embodiment of the invention, the length from the center of the image sensor to the diagonal end is ImgH, the effective diameter of the fifth lens is CA5, the effective diameter of the sixth lens is CA6, and the effective diameter of the seventh lens is CA7. , the equation: CA4 > CA5 > CA6 > (2*Imgh) > CA7 can be satisfied.

According to an embodiment of the invention, the sensor side surface of the fifth lens and the object side surface of the sixth lens may be adhered to each other.

According to an embodiment of the invention, it may include an aperture disposed around the circumference between the first lens and the second lens.

According to an embodiment of the invention, the object-side surface and the sensor-side surface of the third lens may be aspherical on the optical axis, and the object-side surface and sensor-side surface of the seventh lens may be aspherical on the optical axis.

According to an embodiment of the invention, the first to seventh lenses are made of glass, and the number of lenses whose object-side surface and sensor-side surface are spherical on the optical axis is 2 times greater than the number of lenses whose object-side surface and sensor-side surface are aspherical. It could be more than twice that.

According to an embodiment of the invention, the center thickness of the first lens is CT1, the optical axis distance from the center of the object side surface of the first lens to the surface of the image sensor is TTL, and the equation: 0.18 ≤ CT1/TTL ≤ 0.3 can be satisfied.

According to an embodiment of the invention, the maximum of the center thicknesses of the first to seventh lenses is Max_CT, the maximum of the center spacings between the first to seventh lenses is Max_CG, and the equation: 1 < Max_CT/Max_CG < 2 can be satisfied.

An optical system according to an embodiment of the invention includes first to seventh lenses aligned along an optical axis from the object side toward the sensor side; and an aperture disposed between any two of the first lens and the third lens, wherein the first lens has negative refractive power, and the object-side surface and the sensor-side surface of the seventh lens are aspherical, and The composite refractive power of the fourth to seventh lenses is positive, and the difference in effective diameter between the object-side surface and the sensor-side surface of the sixth lens is greater than the effective diameter difference between the object-side surface and the sensor-side surface of each of the first to fourth lenses. It can be big.

According to an embodiment of the invention, the first lens has a meniscus shape convex from the optical axis toward the sensor, and the central thickness of the first lens is greater than the sum of the central thicknesses of two adjacent lenses among the second to seventh lenses. You can.

According to an embodiment of the invention, the lens having the maximum effective diameter among the first to seventh lenses may be disposed between a lens whose object-side surface and sensor-side surface are aspherical on the optical axis and a bonded lens in which two adjacent lenses are joined.

According to an embodiment of the invention, the third lens may be an aspherical lens, and the fifth and sixth lenses may be bonded lenses.

According to an embodiment of the invention, the first to seventh lenses are made of glass, the aperture is disposed around the circumference between the first lens and the second lens, and any one of the first to third lenses is an optical axis. It may be an aspherical lens.

According to an embodiment of the invention, the number of lenses whose object-side surface and sensor-side surface are spherical on the optical axis is more than twice the number of lenses whose object-side surface and sensor-side surface are aspherical, and the effective diameter is smaller than the diagonal length of the image sensor. The number of lenses may be 2 or less.

According to an embodiment of the invention, the fifth and sixth lenses are lenses joined with opposite refractive powers,

The composite focal length of the fifth and sixth lenses may have a positive value.

A camera module according to an embodiment of the invention includes an image sensor; first to seventh lenses aligned along the optical axis from the object side toward the sensor side; An aperture disposed between spherical lenses among the first to seventh lenses: comprising an optical filter between the seventh lens and the image sensor, wherein the first lens has a meniscus shape convex from the optical axis toward the sensor, The first and seventh lenses have negative refractive power, the combined refractive power of the second to seventh lenses is positive, one of the first to fourth lenses is an aspherical lens, and the aspherical lens has two sides on the optical axis. It can be placed between lenses having a convex shape.

According to an embodiment of the invention, the third lens is an aspherical lens and has a meniscus shape convex from the optical axis toward the object, and the second and fourth lenses may have a shape where both sides are convex at the optical axis.

According to an embodiment of the invention, it includes a bonded lens in which two lenses having opposite refractive powers among the fifth to seventh lenses are bonded, and the bonded lens includes a lens that is biconvex on the optical axis and a lens that is biconcave on the optical axis. may include.

According to an embodiment of the invention, the bonded lens is a lens in which the fifth and sixth lenses disposed between the fourth lens and the seventh lens are bonded, and the seventh lens may be an aspherical lens.

According to an embodiment of the invention, the center thickness of the first lens is thicker than the center thickness of the bonded lens, and the center spacing between the third and fourth lenses is the maximum among the center spacings between the first to seventh lenses. It may range from 84% to 95% of the central thickness of the bonded lens.

According to an embodiment of the invention, the number of lenses whose object-side surface and sensor-side surface are spherical is more than twice the number of lenses whose object-side surface and sensor-side surface are aspherical, and at the center of the object-side surface of the first lens. The distance to the surface of the image sensor is TTL, 1/2 of the diagonal length of the image sensor is ImgH, and the maximum effective diameter between the object side and sensor side of the lenses is CA_Max, equation: 2 < TTL / ImgH < 15 and 1 < CA_Max / (2*ImgH) < 3.

The optical system and camera module according to the embodiment may have improved optical characteristics. In detail, in the optical system according to the embodiment, a plurality of lenses may have a set thickness, refractive power, and distance from adjacent lenses. Accordingly, the optical system and camera module according to the embodiment can have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. in a set angle of view range, and can have good optical performance in the periphery of the angle of view.

Additionally, the optical system and camera module according to the embodiment may have good optical performance in a temperature range from low temperature (about -20°C to -40°C) to high temperature (85°C to 105°C). In detail, a plurality of lenses included in the optical system may have set materials, refractive powers, and refractive indices. Accordingly, even when the focal length of each lens changes due to a change in refractive index due to a change in temperature, the lenses can compensate for each other. That is, the optical system can effectively distribute refractive power in a temperature range from low to high temperatures, and prevent or minimize changes in optical properties in the temperature range from low to high temperatures. Therefore, the optical system and camera module according to the embodiment can maintain improved optical properties in various temperature ranges.

Additionally, the optical system and camera module according to the embodiment can satisfy the angle of view set through a combination of an aspherical lens and a spherical lens and implement excellent optical characteristics. Because of this, the optical system can provide a slimmer vehicle camera module. Accordingly, the optical system and camera module can be provided for various applications and devices, and can have excellent optical properties even in harsh temperature environments, for example, when exposed to the exterior of a vehicle or inside a vehicle at high temperatures in the summer.

The invention can improve the reliability of ADAS optical systems and camera modules deployed in vehicles.

1 is a side cross-sectional view of an optical system and a camera module having the same according to an embodiment.
FIG. 2 is a side cross-sectional view for explaining the relationship between the nth and n-1th lenses of FIG. 1.
Figure 3 is a table showing the lens characteristics of the optical system of Figure 1.
FIG. 4 is a table showing the aspheric coefficients of lenses in the optical system of FIG. 1.
Figure 5 is a table showing the thickness of each lens and the spacing between adjacent lenses in the optical system of Figure 1.
FIG. 6 is a table showing CRA (Chief Ray Angle) data at room temperature, low temperature, and high temperature according to the position of the image sensor in the optical system of FIG. 1.
FIG. 7 is a graph showing data on the diffraction MTF (Modulation Transfer Function) of the optical system of FIG. 1 at room temperature.
FIG. 8 is a graph showing data on the diffraction MTF of the optical system of FIG. 1 at low temperature.
FIG. 9 is a graph showing data on the diffraction MTF of the optical system of FIG. 1 at high temperature.
FIG. 10 is a graph showing data on aberration characteristics of the optical system of FIG. 1 at room temperature.
FIG. 11 is a graph showing data on aberration characteristics of the optical system of FIG. 1 at low temperature.
FIG. 12 is a graph showing data on aberration characteristics of the optical system of FIG. 1 at high temperature.
Figure 13 is a graph showing relative illuminance according to the height of the image sensor according to an embodiment.
Figure 14 is an example of a vehicle having an optical system according to an embodiment of the invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. The technical idea of the present invention is not limited to some of the described embodiments, but can be implemented in various different forms, and one or more of the components between the embodiments can be selectively combined as long as it is within the scope of the technical idea of the present invention. , can be used as a replacement. In addition, terms (including technical and scientific terms) used in the embodiments of the present invention, unless explicitly specifically defined and described, are generally understood by those skilled in the art to which the present invention pertains. It can be interpreted as meaning, and the meaning of commonly used terms, such as terms defined in a dictionary, can be interpreted by considering the contextual meaning of the related technology.

The terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention. In this specification, the singular may also include the plural unless specifically stated in the phrase, and when described as "at least one (or more than one) of A and B and C", it is combined with A, B, and C. It can contain one or more of all possible combinations. Additionally, when describing the components of an embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and are not limited to the essence, sequence, or order of the component. And, when a component is described as being 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected, coupled or connected to the other component, but also is connected to the other component. It may also include cases where other components are 'connected', 'coupled', or 'connected' by another component between them. Additionally, when described as being formed or disposed "above" or "below" each component, "above" or "below" refers not only to cases where two components are in direct contact with each other, but also to one This also includes cases where another component described above is formed or placed between two components. In addition, when expressed as "top (above) or bottom (bottom)", it can include not only the upward direction but also the downward direction based on one component.

In the description of the invention, "object side" may refer to the side of the lens facing the object side based on the optical axis (OA), and "sensor side" may refer to the side of the lens facing the imaging surface (image sensor) based on the optical axis. It can refer to the surface of the lens. That one side of the lens is convex may mean a convex shape in the optical axis or paraxial region, and that one side of the lens is concave may mean 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 table for lens data may refer to values (unit, mm) at the optical axis. The vertical direction may mean a direction perpendicular to the optical axis, and the end of the lens or lens surface may mean 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. The paraxial area refers to a very narrow area near the optical axis, and is an area where the distance at which light rays fall from the optical axis (OA) is almost zero. Hereinafter, the meaning of optical axis may include the center of each lens or a very narrow area near the optical axis.

As shown in FIG. 1, the optical system 1000 according to an embodiment of the invention may include a plurality of lens groups LG1 and LG2. In detail, each of the plurality of lens groups LG1 and LG2 includes at least one lens. For example, the optical system 1000 may include a first lens group LG1 and a second lens group LG2 sequentially arranged along the optical axis OA from the object side toward the image sensor 300. .

The number of lenses in each of the first lens group (LG1) and the second lens group (LG2) may be different. The number of lenses of the second lens group (LG2) may be greater than the number of lenses of the first lens group (LG1), for example, 4 times or 5 times the number of lenses of the first lens group (LG1). You can.

The first lens group LG1 may include at least one lens. The first lens group LG1 may have two or less lenses. The first lens group LG1 may preferably include one lens. The second lens group LG2 may include two or more lenses. The second lens group LG2 may have 5 or more lenses, and preferably may have 6 lenses. The optical system 1000 may include n lenses, the nth lens may be the last lens, and the n-1th lens may be the lens closest to the last lens. The n is an integer of 5 or more, for example, may be 5 to 8.

The first lens group LG1 may include at least one lens made of glass. The first lens group LG1 may provide the lens closest to the object side as a glass lens. This glass material has a small amount of expansion and contraction due to changes in external temperature, and its surface is less likely to be scratched, preventing surface damage.

The lens material of the second lens group LG2 may include lenses made of glass. The second lens group LG2 may include five or more lenses made of glass, for example, 5 to 8 lenses made of glass. The lenses of the first and second lens groups (LG1, LG2) may all be made of glass, and the amount of expansion and contraction of the lenses made of glass according to temperature changes is smaller than that of plastic materials, and the optical properties deteriorate through thermal compensation. can be prevented. As another example, among the lenses of the second lens group LG2, one or two lenses closest to the image sensor 300 may be made of plastic or may be provided as an aspherical lens.

The lenses of the first lens group LG1 may be spherical lenses. The lenses of the second lens group LG2 may include at least one aspherical lens and two or more spherical lenses. The aspherical lens is a lens in which the object-side surface and the sensor-side surface are aspherical, and the spherical lens is a lens in which the object-side surface and the sensor-side surface are spherical. In the second lens group LG2, the number of spherical lenses may be more than twice the number of aspherical lenses. The aspherical lenses can prevent spherical aberration within the optical system 1000, and since aberration does not occur even if the effective diameter is increased, it is possible to miniaturize and lighten the camera module.

The aspherical lens may be made of a glass mold material. The lenses of the second lens group LG2 may include at least one non-mold material and at least one mold material. For example, in the second lens group LG2, the number of lenses made of glass non-mold material may be more than twice that of the lenses made of glass mold material. Both the non-mold material and the mold material may be glass materials. The non-mold lens is a finely processed lens without injection molding, and the mold lens is an injection molded lens.

The optical system 1000 is arranged with lenses made of glass, and since the change rate of contraction and expansion of the glass lenses according to temperature changes is smaller than that of plastic materials, heat compensation is possible within the lens barrel, and temperature changes are possible. Deterioration of optical properties can be suppressed. Additionally, since glass lenses include at least two aspherical lenses, the occurrence of various aberrations can be suppressed.

Among the lenses of the optical system 1000, the lens with the maximum Abbe's number may be located in the second lens group (LG2), and the lens with the maximum refractive index may be located in the first lens group (LG1) or the second lens. It may be located in the county (LG2). The maximum Abbe number may be 55 or more, and the maximum refractive index may be 1.70 or more. A lens with the maximum Abbe number can reduce chromatic dispersion, and a lens with the maximum refractive index can increase chromatic dispersion of incident light.

The lens having the maximum effective diameter within the optical system 1000 may be a lens disposed on the sensor side of the aspherical lens closest to the object side. Here, when there are two or more object-side aspherical lenses, one may be located on the object side and one may be located closest to the sensor side. Preferably, the lens having the maximum effective diameter may be a lens made of glass, for example, a spherical lens made of glass. The effective diameter of each lens may be the diameter of the effective area where effective light is incident from each lens, and is the average of the effective diameter of the object side surface and the effective diameter of the sensor side surface. Embodiments of the invention can reduce the weight of the camera module, provide a cheaper manufacturing cost, and suppress deterioration of optical characteristics due to temperature changes by further mixing aspheric lenses in the optical system 1000. You can.

Each of the lenses may include an effective area and an unactive area. The effective area may be an area through which light incident on each of the lenses passes. That is, the effective area may be defined as an effective area or effective diameter in which the incident light is refracted to realize optical characteristics. The non-effective area may be arranged around the effective area. The non-effective area may be an area where effective light does not enter the plurality of lenses. That is, the non-effective area may be an area unrelated to the optical characteristics. Additionally, the end of the non-effective area may be an area fixed to a lens barrel (not shown) that accommodates the lens.

The total top length (TTL) within the optical system 1000 may be greater than 4 times that of ImgH, for example, greater than 4 times and less than 15 times. Preferably, the condition of 4 < TTL/ImgH < 10 can be satisfied. The total track length (TTL) is the distance on the optical axis (OA) from the center of the object side surface of the first lens to the surface of the image sensor 300. The ImgH is the distance from the optical axis (OA) to the diagonal end of the image sensor 300 or 1/2 of the maximum diagonal length. In the optical system 1000, the effective focal length (EFL) is 10 mm or more and the diagonal angle of view (FOV) is less than 45 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 module for an Advanced Driving Assistance System (ADAS) installed inside or outside a vehicle.

The optical system 1000 may have a value of TTL/(2*ImgH) greater than 2, for example, greater than 2 but less than 7.5, or may have the condition of 2 < TTL/(2*ImgH) < 5. The optical system 1000 sets the value of TTL/(2*ImgH) to be greater than 2, thereby providing a lens optical system for a vehicle. The total number of lenses in the first and second lens groups (LG1 and LG2) is 8 or less. Accordingly, the optical system 1000 can provide an image without exaggeration or distortion for the image being formed.

The length of the image sensor 300 is the maximum length of the diagonal line in the direction perpendicular to the optical axis OA. In the optical system 1000, the number of lenses having an effective diameter larger than the length of the image sensor 300 is more than 70%, and the number of lenses having an effective diameter smaller than the length of the image sensor 300 is 30% or less, for example, 10% to 10%. It may be in the 30% range. At least one of the aspherical lenses in the optical system 1000 may have an effective diameter smaller than the length of the image sensor 300, and at least one of the aspherical lenses may have an effective diameter larger than the length of the image sensor 300.

The effective diameter of the lens closest to the object within the lens unit 100 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. By controlling the effective diameter size of each lens, the optical system 1000 can control incident light to compensate for deterioration in resolution and optical characteristics due to temperature changes, and improve chromatic aberration control characteristics. The optical system 1000 ) can be improved.

The optical system 1000 may include at least one bonded lens 156 therein. The bonded lens 156 may be a lens in which two lenses with different focal lengths are bonded together. The object-side surface and the sensor-side surface of the bonded lens 156 may have an effective diameter larger than the length of the image sensor 300. The effective diameter of the lens(s) disposed on the sensor side rather than the bonded lens 156 may be smaller than the length of the image sensor 300. Additionally, the effective diameters of the lenses located closer to the object than the bonded lens 156 may be larger than the length of the image sensor 300. The sensor side of the bonded lens 156 may be disposed in the range of 100% to 110% of the length of the image sensor 300. The bonded lens 156 may be a lens whose object-side surface and sensor-side surface are spherical.

The optical system 1000 according to the embodiment may include an aperture (ST). The aperture ST can control the amount of light incident on the optical system 1000. The aperture ST may be disposed between any two lenses in the lens unit 100. In lenses disposed between an object and the aperture ST, the effective diameter of the lens surface tends to become smaller as it moves from the object side to the aperture ST. In the lenses disposed between the aperture ST and the image sensor 300, the effective diameter of the lens surfaces tends to become larger or smaller as it moves from the aperture ST to the sensor. 'The effective diameter of the lenses tends to become larger or smaller as it moves from the aperture (ST) to the sensor side' means that, in the lenses disposed between the aperture (ST) and the image sensor 300, the It may include a lens whose effective diameter of the lens surface increases and a lens whose effective diameter decreases as it moves from the aperture ST toward the sensor. In the lenses disposed between the aperture ST and the image sensor, as in an embodiment of the present invention, the effective diameter of the lens surfaces increases and then decreases as it moves from the aperture ST toward the sensor.

A first lens 101 is disposed on the object side of the aperture ST, and a second lens 102, a third lens 103, and a fourth lens 104 are disposed on the sensor side of the aperture ST. You can. When the aperture ST is disposed on the sensor side of the first lens 101, the effective diameter of the sensor side of the first lens (effective diameter of the aperture) < the effective diameter of the object side of the first lens < the effective diameter of the second lens The condition of effective diameter of the object side < effective diameter of the sensor side of the second lens is satisfied. The condition of effective diameter of the sensor-side surface of the second lens 102 < effective diameter of the object-side surface of the third lens < effective diameter of the object-side surface of the fourth lens is satisfied.

The aperture ST may be placed at a set position. For example, the aperture ST may be disposed around the object-side surface of the lens closest to the object side among the lenses of the second lens group LG2. Alternatively, the aperture ST may be disposed around the object-side surface of the object-side lens of the first lens group LG1. Alternatively, at least one lens selected from among the plurality of lenses may function as an aperture. In detail, the object side or the sensor side of one lens selected from among the lenses of the optical system 1000 may function as an aperture to adjust the amount of light.

The optical axis spacing between the first lens group (LG1) and the second lens group (LG2) on the optical axis (OA) is the sensor side of the lens closest to the sensor side among the lenses in the first lens group (LG1). It may be the optical axis spacing between the object side surfaces of the lens closest to the object side among the lenses in the second lens group LG2. The optical axis spacing between the first lens group LG1 and the second lens group LG2 may be smaller than the center spacing between the object-side aspherical lens and the sensor-side spherical lens within the lens unit 100. Additionally, the optical axis spacing between the first lens group LG1 and the second lens group LG2 may be smaller than the center spacing between the object-side spherical lens and the sensor-side aspherical lens. The optical axis spacing between the first lens group LG1 and the second lens group LG2 may be the center spacing between the spherical lenses.

In an embodiment, the optical axis interval between the first lens group (LG1) and the second lens group (LG2) may be less than 1 times the optical axis distance of the first lens group (LG1), for example, the first lens group (LG1) It may be greater than 0 and less than 0.5 times the optical axis distance of LG1). The optical axis distance between the first lens group LG1 and the second lens group LG2 may be less than 0.5 times the optical axis distance of the second lens group LG2, for example, more than 0 times and less than 0.2 times. The optical axis distance of the second lens group LG2 is the optical axis distance between the object side of the lens closest to the object side of the second lens group LG2 and the sensor side of the lens closest to the image sensor 300.

Here, the first lens group LG1 may be a lens located closer to the object than the aperture ST, and the second lens group LG2 may be a lens located closer to the sensor than the aperture ST. The first lens group (LG1) and the second lens group (LG2) can be divided into an object-side lens group and a sensor-side lens group based on the aperture (ST). The sensor-side surface of the first lens group LG1 may be convex on the optical axis, and the object-side surface of the second lens group LG2 may have a convex shape on the optical axis, and may be opposed to each other.

The first lens group LG1 may have negative (-) refractive power, and the second lens group LG2 may have positive (+) refractive power. In the first lens group (LG1), the lens closest to the object side has negative (-) refractive power, and among the lenses in the second lens group (LG2), the lens closest to the sensor side has negative (-) refractive power. You can have That is, the refractive power of the object-side first lens 101 has a negative value, and the composite focal length of the second to seventh lenses 102-107 has a positive value.

When the focal length of the first lens group (LG1) is F_LG1 and the focal length of the second lens group (LG2) is F_LG2, F_LG1 < F_LG2 can be satisfied, and preferably, |F_LG1| > F_LG2 can be satisfied. In other words, F_LG1 < 0 can be satisfied.

Here, in the case where the composite focal length of the first to third lenses 101-103 in the optical system 1000 is set to F13, and the composite focal length of the fourth to seventh lenses 104-107 is set to F47, F13 < F47 can be satisfied, and F13, F47 > 0 can be satisfied. Also, FLG2 < F13, |F_LG1| < F47 can be satisfied.

The first lens group (LG1) diffuses the light incident through the object side, and the second lens group (LG2) is in close contact with the sensor side of the first lens group (LG1) The light emitted through (LG1) can be refracted to the image sensor 300. The optical axis gap between the first lens group LG1 and the second lens group LG2 may be less than 1 mm, for example, 0.8 mm or less.

When expressing the focal length as an absolute value, the focal length of the first lens group LG1 may be 1.5 times or more, for example, 1.5 to 7 times the focal length of the second lens group LG2. The effective focal length (EFL) of the optical system 1000 may be smaller than the absolute value of the focal length of the first lens group LG1. The effective focal length (EFL) of the optical system 1000 may be smaller than the absolute value of the focal distance of the first lens group (LG1) and greater than the absolute value of the focal distance of the second lens group (LG2).

The lens unit 100 may be a mixture of spherical lenses and aspherical lenses. The number of lenses of the aspherical lens may be less than 50% of the total number of lenses, and may range from 10% to 45%. When expressing the absolute value of the focal length, the average of the composite focal lengths of the spherical lenses may be smaller than the average of the composite focal lengths of the aspherical lenses. The average refractive index of the aspherical lenses may be smaller than the average refractive index of the spherical lenses. Additionally, the difference between the average effective diameter of the spherical lenses and the average effective diameter of the aspherical lenses may be 1 mm or more, for example, in the range of 1 mm to 3 mm. Accordingly, when two or more aspherical lenses are disposed within the camera module, the weight of the camera module can be reduced and optical characteristics can be improved.

The average Abbe number of the spherical lenses within the lens unit 100 may be greater than the average Abbe number of the aspherical lenses. Since the lenses adjacent to the image sensor 300 are arranged to have a low Abbe number and a high refractive index, color dispersion can be improved by the lenses adjacent to the image sensor 300. For example, the product of the Abbe number and the refractive index of the nth lens, which is the last lens, may be smaller than the product of the Abbe number and the refractive index of the n-2th, n-3th, n-4th, or n-5th lenses. Additionally, the product of the Abbe number and the refractive index of the n-1th lens may be smaller than the product of the Abbe number and the refractive index of the n-2th, n-3th, n-4th, or n-5th lenses.

In the optical system 1000, the number of lenses with negative (-) refractive power may be smaller than the number of lenses with positive (+) refractive power. The number of lenses with negative (-) refractive power may be less than 50% of the total number of lenses, for example, in the range of 20% to 45%.

The sum of the refractive indices of the lenses of the lens unit 100 of the embodiment may be 8 or more, for example, in the range of 8 to 15, and the average of the refractive indices may be in the range of 1.60 to 1.72. The sum of the Abbe numbers of each of the lenses may be 220 or more, for example, in the range of 220 to 380, and the average of the Abbe numbers may be 55 or less, for example, in the range of 31 to 55. The sum of the central thicknesses of all lenses may be 15 mm or more, for example, in the range of 15 mm to 30 mm or 15 mm to 28 mm. The average of the central thicknesses of the entire lens may be 4 mm or less, for example, in the range of 2.7 mm to 4 mm. The sum of the center spacings between the lenses at the optical axis (OA) may be greater than 5 mm, for example in the range of 5 mm to 20 mm, and may be less than the sum of the center thicknesses of the lenses. Additionally, the average value of the effective diameter of each lens surface of the lens unit 100 may be 8 mm or more, for example, in the range of 8 mm to 15 mm. The difference between the maximum and minimum effective diameters may be less than 5 mm. Therefore, it is possible to provide an optical system in which the difference in effective diameter of each lens surface is not large, and the assembly quality of the lenses assembled in the lens barrel can be improved.

In the case where the number of aspherical lenses in the lens unit 100 is Ma, the number of lenses with an effective diameter smaller than the diagonal length of the image sensor 300 is Mb, and the number of lenses with negative refractive power is Mc, Mb ≤ Ma < The condition of Mc can be satisfied, and preferably the condition of Mb < Ma can be satisfied.

In the case where the number of lens surfaces with an aspherical surface in the lens unit 100 is Ma1, the number of lens surfaces with an effective diameter smaller than the diagonal length of the image sensor 300 is Mb1, and the number of lenses with negative refractive power is Mc. , the condition Mb1 ≤ Mc < Ma1 can be satisfied, and preferably the condition Mb1 < Mc can be satisfied.

The number of lens surfaces having an aspherical surface within the lens unit 100 is Ma1, the number of lens surfaces that are aspherical and have an effective diameter smaller than the diagonal length of the image sensor 300 is Ma2, and the number of lenses with negative refractive power is Mc In this case, the condition Ma2 < Mc < Ma1 can be satisfied.

In the case where the number of spherical lenses in the lens unit 100 is Ga, the number of lenses with an effective diameter larger than the diagonal length of the image sensor 300 is Gb, and the number of lenses with positive refractive power is Gc, Gc < Ga ≤ The condition of Gb can be satisfied, and preferably the condition of Ga < Gb can be satisfied.

The F number of the optical system or camera module according to an embodiment of the invention may be 2.4 or less, for example, in the range of 1.4 to 2.4 or 1.5 to 1.8. In the optical system according to an embodiment of the invention, the maximum angle of view (diagonal) may be 50 degrees or less, for example, in the range of 20 degrees to 55 degrees or 25 degrees to 40 degrees. The horizontal field of view (FOV_H) of the vehicle optical system in the Y-axis direction may be greater than 20 degrees and less than 40 degrees, for example, in the range of 25 degrees to 35 degrees. Additionally, the vertical angle of view is provided at a smaller angle than the horizontal angle of view, and may be 20 degrees or less, for example, in the range of 10 to 20 degrees. At this time, the sensor length in the horizontal direction (Y) may be 8.064 mm ± 0.5 mm, and the sensor height in the vertical direction (X) may be 4.54 mm ± 0.5 mm. The horizontal angle of view (FOV_H) is the angle of view based on the horizontal length of the sensor. Accordingly, it is possible to suppress changes in the focus imaging position due to temperature changes, and it is possible to provide a vehicle camera in which various aberrations are well corrected.

The optical system 1000 or camera module may include an image sensor 300. The image sensor 300 can detect light and convert it into an electrical signal. The image sensor 300 can detect light that sequentially passes through the lens unit 100. The image sensor 300 may include an element capable of detecting incident light, such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

Here, the length of the image sensor 300 is the maximum length in the diagonal direction orthogonal to the optical axis OA, is smaller than the effective diameter of the lens closest to the object side in the first lens group LG1, and is smaller than the effective diameter of the lens closest to the object side in the first lens group LG1. It may be larger than the effective diameter of the lens closest to the sensor within the lens group (LG2). Here, the number of lenses having an effective diameter larger than the length of the image sensor 300 may be 5 to 6, and the number of lenses having an effective diameter smaller than the length of the image sensor 300 may be 1 to 2.

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

The cover glass 400 is disposed between the optical filter 500 and the image sensor 300, protects the upper part of the image sensor 192, and can prevent the reliability of the image sensor 192 from deteriorating. The cover glass 400 can be removed.

The optical filter 500 may include an infrared filter or an infrared cut-off filter. The optical filter 500 may pass light in a set wavelength band and filter light in a different wavelength band. When the optical filter 500 includes an infrared filter, radiant heat emitted from external light can be blocked from being transmitted to the image sensor 300. Additionally, the optical filter 500 can transmit visible light and reflect infrared rays.

Since the embodiment is an optical system applied to a vehicle camera, the first lens can be made of glass even though it is designed using both an aspherical lens and a spherical lens. This has the advantage that glass material is more resistant to scratches than plastic material and is not sensitive to external temperature. In order to more effectively prevent scratches placed inside the vehicle or caused by foreign substances, a glass lens is used as the first lens, and the object-side surface of the first lens may have a concave shape so as not to contact external structures. If the object-side surface of the first lens is designed to have a convex shape, scratches may occur due to contact with an external structure. For driver monitoring when driving a vehicle, photographing the front/rear of the vehicle, or detecting lanes and unexpected objects around the vehicle, the horizontal angle of view may be greater than 20 degrees and less than 40 degrees, for example, in the range of 25 degrees to 35 degrees. This horizontal angle of view may be a preset angle for an advanced driver assistance system (ADAD).

The optical system 1000 according to the embodiment may further include a reflective member (not shown) to change the path of light. The reflective member may be implemented as a prism that reflects incident light from the first lens group LG1 in the direction of the lenses. Hereinafter, the optical system according to the embodiment will be described in detail.

An optical system according to an embodiment of the invention will be described.

FIG. 1 is a side cross-sectional view of an optical system and a camera module having the same according to an embodiment, FIG. 2 is a side cross-sectional view for explaining the relationship between the nth and n-1th lenses according to FIG. 1, and FIG. 3 is the optical system of FIG. 1. is a table showing the lens characteristics, Figure 4 is a table showing the aspherical coefficients of the lenses in the optical system of Figure 1, Figure 5 is a table showing the thickness of each lens and the gap between adjacent lenses in the optical system of Figure 1, and Figure 6 is a table showing the thickness of each lens and the gap between adjacent lenses. A table showing CRA (Chief Ray Angle) data at room temperature, low temperature, and high temperature according to the position of the image sensor in the optical system of Figure 1, and Figures 7 to 9 show the diffraction MTF at room temperature, low temperature, and high temperature of the optical system of Figure 1. It is a graph showing data on (Modulation Transfer Function), and Figures 10 to 12 are graphs showing data on aberration characteristics of the optical system of Figure 1 at room temperature, low temperature, and high temperature.

Referring to FIGS. 1 to 3, the optical system 1000 according to the embodiment includes a lens unit 100, and the lens unit 100 may include first lenses 101 to seventh lenses 107. You can. The first to seventh lenses 101, 102, 103, 104, 105, 106, and 107 may be sequentially aligned along the optical axis OA. Light corresponding to object information may pass through the first to seventh lenses 101 to 107 and the optical filter 500 and be incident on the image sensor 300.

The first lens 101 is the lens closest to the object in the first lens group LG1. The seventh lens 107 is the closest lens to the image sensor 107 in the second lens group LG2 or lens unit 100. The first lens 101 may be a first lens group (LG1), and the second to seventh lenses (102, 103, 104, 105, 106, and 107) may be a second lens group (LG2).

The first lens 101 may have positive (+) or negative (-) refractive power at the optical axis (OA). The first lens 101 may have negative (-) refractive power. The first lens 101 may include a plastic material or a glass material, for example, a glass material or a glass non-mold material. The first lens 101 made of glass can reduce changes in the center position and radius of curvature due to temperature changes depending on the surrounding environment, and protect the incident side surface of the optical system 1000.

With respect to the optical axis, the object-side first surface S1 of the first lens 101 may be concave, and the sensor-side second surface S2 may be convex. The first lens 101 may have a meniscus shape convex from the optical axis toward the sensor. Differently, at the optical axis OA, the first surface S1 may have a convex shape, and the second surface S2 may have a concave shape. This first lens 101 can be made of a glass material with the thickest thickness, preventing a decrease in rigidity due to external impact, and improving optical performance when the temperature changes to low or high temperatures due to the glass material. It can be kept constant. In addition, since the glass material is spherical, the change in the refractive index of light is not large even if the lens is designed to be thick. Here, the thickness of the lens may be an average of the center thickness and edge thickness. The thickness of the first lens 101 may be the thickest within the lens unit 100. The thickness of the first lens 101 may be thicker than the thickness of the bonded lens 156. The central thickness of the first lens 101 may be thicker than the central thickness of the bonded lens 156. The edge thickness of the first lens 101 may be thicker than the edge thickness of the bonded lens 156.

Since the first surface (S1) is concave and the second surface (S2) is convex on the optical axis, incident light can be refracted in a direction away from the optical axis, and the center spacing between the first and second lenses (101 and 102) It is possible to reduce the effective diameter of the second lens 102. The first surface S1 of the first lens 101 may be provided without a critical point from the optical axis OA to the end of the effective area, that is, the edge. The second surface S2 of the first lens 101 may be provided without a critical point.

The aperture ST may be disposed around the sensor side of the first lens 101. Alternatively, the aperture ST may be disposed around the object-side or sensor-side surface of the second lens 102, or around the object-side surface of the third lens 103.

The second lens 102 may be disposed between the first lens 101 and the third lens 103. The second lens 102 may have positive (+) or negative (-) refractive power at the optical axis (OA). The second lens 102 may have positive (+) refractive power. The second lens 102 may include plastic or glass. For example, the second lens 102 may be made of glass.

Based on the optical axis OA, the object-side third surface S3 of the second lens 102 may be convex, and the sensor-side fourth surface S4 may be convex. The second lens 102 may have a shape in which both sides are convex at the optical axis. Alternatively, the third surface S3 may be convex and the fourth surface S4 may be concave. Alternatively, the second lens 102 may have a concave shape on both sides. The second lens 102 may be provided as a spherical lens made of glass. The third surface S3 and the fourth surface S4 may be spherical. At least one or both of the third surface S3 and the fourth surface S4 may be provided without a critical point from the optical axis OA to the end of the effective area.

The third lens 103 may have positive (+) or negative (-) refractive power at the optical axis (OA). The third lens 103 may have positive (+) refractive power. The third lens 103 may include plastic or glass. For example, the third lens 103 may be made of glass or a glass mold.

Based on 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 concave. The third lens 103 may have a meniscus shape convex from the optical axis toward the object. Alternatively, the third lens 103 may have a meniscus shape that is convex toward the sensor. Alternatively, the third lens 103 may have a concave shape on both sides of the optical axis.

The third lens 103 may be provided as an aspherical lens made of glass. The fifth surface S5 and the sixth surface S6 may be aspherical, and aspheric coefficients may be provided as L3S1 and L3S2 in FIG. 4. At least one or both of the fifth surface S5 and the sixth surface S6 may be provided without a critical point from the optical axis OA to the end of the effective area.

In the optical system 1000, there may be one or more lenses made of glass having an aspherical surface, for example, one to three lenses. The effective radius of the fifth surface (S5) or the sixth surface (S6) of the third lens 103 is the effective radius of the object-side surface or sensor-side surface of the first lens 101 or the seventh lens 107. It can be bigger than others. The effective diameter of the third lens 103 may have the second largest effective diameter within the lens unit 100. The effective diameter of the third lens 103 may have the largest effective diameter among aspherical lenses.

Since the second lens 102 disposed on the sensor side of the aperture ST has positive refractive power (F2 > 0), the second lens 102 can refract incident light in the optical axis direction. It is possible to suppress an increase in the effective diameter of the sensors or rear lenses of the second lens 102. Accordingly, the second lens 102 can prevent a decrease in the yield by weight of the optical system and improve production efficiency. Here, the composite focal length of the second to seventh lenses 102-107 disposed on the sensor side of the aperture ST may have a positive value, and the TTL may be reduced within the angle of view range.

The gap between the second lens 102 and the third lens 103 may gradually increase from the center to the edge. This gap may gradually increase from the optical axis toward the edge due to the shape of the sensor-side surface of the second lens 102 being convex and the object-side surface of the third lens 103 being convex.

The fourth lens 104 may have positive (+) or negative (-) refractive power at the optical axis (OA). The fourth lens 104 may have positive (+) refractive power. The fourth lens 104 may include plastic or glass. For example, the fourth lens 104 may be made of glass.

Based on the optical axis, the object-side seventh surface S7 of the fourth lens 104 may be convex, and the sensor-side eighth surface S8 may be convex. The fourth lens 104 may have a shape in which both sides are convex at the optical axis. Alternatively, at the optical axis OA, the seventh surface S7 may have a concave shape, and the eighth surface S8 may have a concave or convex shape. Alternatively, the fourth lens 104 may have a meniscus shape that is convex toward the sensor.

The fourth lens 104 may be provided as a spherical lens made of glass. The seventh surface (S7) and the eighth surface (S8) may be spherical. 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.

The fifth lens 105 may have positive (+) or negative (-) refractive power at the optical axis (OA). The fifth lens 105 may have positive (+) refractive power. The fifth lens 105 may include plastic or glass. For example, the fifth lens 105 may be made of glass.

Based on the optical axis OA, the ninth surface S9 on the object side of the fifth lens 105 may be convex and the tenth surface S10 on the sensor side may be convex. The fifth lens 105 may have a shape in which both sides are convex at the optical axis OA. Differently, at the optical axis OA, the ninth surface S9 may have a concave shape, and the tenth surface S10 may have a convex shape. Alternatively, the ninth surface S9 may have a concave shape, and the tenth surface S10 may have a concave shape.

The fifth lens 105 may be a spherical lens. The ninth surface S9 and the tenth surface S10 of the fifth lens 105 may be spherical. At least one or both of the ninth surface S9 and the tenth surface S10 may be provided without a critical point from the optical axis OA to the end of the effective area.

The sixth lens 106 may have positive (+) or negative (-) refractive power at the optical axis (OA). The sixth lens 106 may have negative refractive power. The sixth lens 106 may include plastic or glass. For example, the sixth lens 106 may be made of glass.

Based on the optical axis OA, the 11th surface on the object side of the sixth lens 106 may be concave and the 12th surface S12 on the sensor side may be concave. The sixth lens 106 may have a concave shape on both sides of the optical axis OA. Alternatively, the sixth lens 106 may have a meniscus shape that is convex toward the sensor, or a shape that is convex on both sides.

The sixth lens 106 may be spherical. For example, the 11th surface and the 12th surface S12 may be spherical. The 11th surface S11 of the sixth lens 106 may be provided without a critical point from the optical axis OA to the end of the effective area. The twelfth surface S12 may be provided without a critical point from the optical axis OA to the end of the effective area.

The fifth lens 105 and the sixth lens 106 can be bonded and can be defined as a bonded lens 156. The bonding surface between the fifth lens 105 and the sixth lens 106 may be defined as the tenth surface S10. The tenth surface S10 may be the same as the eleventh surface of the sixth lens 106. When the gap between the fifth and sixth lenses 105 and 106 is G5, G5 may be less than 0.01 mm. The gap G5 between the fifth and sixth lenses 105 and 106 may be less than 0.01 mm from the optical axis OA to the end of the effective area. The fifth and sixth lenses 105 and 106 may have opposite refractive powers. The combined refractive power of the fifth and sixth lenses 105 and 106 may have positive (+) refractive power.

The product of the refractive power of the object-side fifth lens 105 of the bonded lens 156 and the refractive power or focal length of the sensor-side sixth lens 106 may be less than 0. Accordingly, the aberration characteristics of the optical system can be improved. If the signs of the refractive powers of the two lenses of the bonded lens 156 are the same, there is a limit to improving the aberration.

The composite refractive power of the bonded lens 156 has positive refractive power, the fourth lens 104 disposed on the object side with respect to the bonded lens 156 has positive refractive power, and the seventh lens 104 disposed on the sensor side has positive refractive power. Lens 107 may have negative refractive power. Accordingly, the fourth lens 104, the bonded lens 156, and the seventh lens 107 can refract some of the incident light in the optical axis direction.

The effective diameter of the bonded lens 156 may be larger than the diagonal length of the image sensor 300. The effective diameter of the fifth lens 105 is the average of the effective diameters of the ninth surface (S9) and the tenth surface (S10), and the effective diameters of each of the ninth surface (S9) and the tenth surface (S10) are the image sensor 300. ) can be larger than the diagonal length of The effective diameter of the sixth lens 106 may be smaller than the effective diameter of the fifth lens 105 and larger than the diagonal length of the image sensor 300.

The effective diameter of the seventh surface (S7) of the fourth lens 104 may be larger than the diagonal length of the image sensor 300, and the effective diameter of the twelfth surface (S12) of the sixth lens 106 may be larger than the diagonal length of the image sensor 300. It may be larger than the diagonal length of (300).

When the sixth lens 106 is a spherical lens and the seventh lens 107 is an aspherical lens, the effective diameter difference between the object-side 11th surface and the sensor-side 12th surface S12 of the sixth lens 106 is It may be the largest within the lens unit 100. For example, if the effective diameter of the 9th surface of the sixth lens 106 and the effective diameter of the 12th surface (S12) on the sensor side are CA61 and CA62, the condition CA61 > CA62 is satisfied, and the difference between CA61 and CA62 is the difference between each lens. It may be the largest of the effective diameter differences between the object side and the sensor side. Accordingly, the difference in effective diameter between the object-side surface and the sensor-side surface of the sixth lens 106 can be maximized, and light can be guided to the effective area of the aspherical lens having a relatively small effective diameter. Accordingly, a slimmer optical system can be provided.

The effective diameter of the sixth lens 106 may satisfy the condition of 1.10 < CA61/CA62 < 1.50.

The bonded lens 156 is made of glass lenses having different refractive indexes, has a spherical refractive surface, and at least one lens disposed on the sensor side of the bonded lens 156 is an aspherical lens, thereby causing spherical aberration. can compensate. Additionally, the lens disposed on the sensor side rather than the bonded lens 156 is an aspherical lens and has a small effective diameter, so light can be guided to the entire area of the image sensor 300 through the aspherical lens. The position of the bonded lens 156 is disposed between the aspherical third lens 103 and the aspherical seventh lens 107, or between the spherical fourth lens 104 and the aspherical seventh lens 107. Because it is located, chromatic aberration correction can be more efficient. By placing a bonded lens 156 within the optical system, TTL can be reduced.

The seventh lens 107 may have positive (+) or negative (-) refractive power at the optical axis (OA). The seventh lens 107 may have negative refractive power. The seventh lens 107 may include plastic or glass. For example, the seventh lens 107 may be made of glass or a glass mold.

On the optical axis, the object-side 13th surface S13 of the seventh lens 107 may be convex, and the sensor-side 14th surface S14 may be concave. The seventh lens 107 may have a meniscus shape convex from the optical axis toward the object. Differently, at the optical axis OA, the 13th surface S13 may have a concave shape, and the 14th surface S14 may have a convex shape. Alternatively, the seventh lens 107 may have a concave shape on both sides. The seventh lens 107 may be made of glass and have aspherical surfaces on both sides. The 13th surface S13 and the 14th surface S14 have an aspherical surface, and aspheric coefficients may be provided as L7S1 and L7S2 in FIG. 4.

The seventh lens 107 may be an aspherical lens closest to the image sensor 300. By arranging the aspherical lens closest to the image sensor 300, deterioration of optical performance can be prevented, aberration characteristics can be improved, and the impact on resolution can be controlled. Additionally, by arranging the aspherical lens as the lens closest to the image sensor 300, it can be insensitive to assembly tolerances compared to the spherical lens. In other words, it is insensitive to assembly tolerances, meaning that even if it is assembled with a slight difference from the design, it may not significantly affect optical performance.

Referring to FIG. 2, at least one or both of the 13th surface S13 and the 14th surface S14 of the seventh lens 107 may have a critical point. The 13th surface S13 of the seventh lens 107 may have at least one critical point from the optical axis OA to the end of the effective area. The critical point of the 13th surface S13 may be located at less than 50% of the effective radius of the optical axis OA, or may be located at 30% to 50%, or 35% to 40% of the effective radius. The critical point of the 13th surface S13 may be located 2.1 mm or less from the optical axis OA, for example, in the range of 1.4 mm to 2.1 mm or 1.6 mm to 2 mm. As another example, the 13th surface S13 may be provided without a critical point.

The 14th surface S14 of the seventh lens 107 may have at least one critical point from the optical axis OA to the end of the effective area. The critical point of the 14th surface S14 may be located at a distance of 65% or more of the effective radius from the optical axis OA, or may be located in the range of 65% to 85% or 70% to 80% of the effective radius. The critical point of the fourteenth surface S14 may be located 3.5 mm or more from the optical axis OA, for example, in the range of 3.5 mm to 4.3 mm or 3.6 mm to 4.2 mm. Since the critical point of the 14th surface (S14) of the seventh lens 107 is disposed further outside than the critical point of the 13th surface (S13), the incident light can be refracted to the periphery of the image sensor 300. .

Back focal length (BFL) is the optical axis distance from the image sensor 300 to the last lens. A tangent line K1 passing through an arbitrary point of the 14th surface S14 of the seventh lens 107 and a normal line K2 perpendicular to the tangent line K1 have a predetermined angle θ1 with the optical axis OA. You can have The maximum tangent angle θ1 on the fourteenth surface S14 in the first direction .

The maximum tangent angle on the 13th surface S13 in the first direction

In FIG. 2, CT7 is the center thickness or optical axis thickness of the seventh lens 107, and ET7 is the edge thickness of the seventh lens 107. CT6 is the center thickness or optical axis thickness of the sixth lens 106, and ET6 is the edge thickness of the sixth lens 106. The edge thickness is the distance in the optical axis direction between the object side and the sensor side at the end of the effective area of each lens. CG6 is the optical axis distance (ie, center spacing) from the center of the sixth lens 106 to the center of the seventh lens 107. That is, CG6 is the distance from the center of the 12th surface (S12) to the center of the 13th surface (S13). EG6 is the distance (ie, edge spacing) in the optical axis direction from the edge of the sixth lens 106 to the edge of the seventh lens 107.

FIG. 3 is an example of lens data of the optical system of the embodiment of FIG. 1. As shown in Figure 3, the radius of curvature at the optical axis (OA) of the first to seventh lenses (101, 102, 103, 104, 105, 106, 107), the center thickness of the lens (CT), the center distance between adjacent lenses (CG), d -You can set the size of the refractive index, Abbe's Number, and clear aperture (CA) in the line.

If the radius of curvature of each lens on the optical axis is expressed as an absolute value, the radius of curvature of the eighth surface S8 of the fourth lens 104 on the optical axis OA is the largest among the lenses, and the radius of curvature of the eighth surface S8 of the fifth lens 105 is the largest among the lenses. The radius of curvature of the surface S9 or the twelfth surface S12 of the sixth lens 106 may be the smallest among the lenses. The difference between the maximum radius of curvature and the minimum radius of curvature may be 5 times or more, for example, in the range of 5 to 20 times. The radius of curvature of the third lens 103, which is an aspherical lens, may be smaller than the radius of curvature of the first, second, and fourth lenses 101, 102, and 104 made of glass. Here, the radius of curvature is the average of the absolute values of the radii of curvature of the object-side surface and the sensor-side surface of each lens.

The radius of curvature of the first lens 101 disposed on the object side of the aperture ST in the optical axis may be larger than the radius of curvature of the second lens 102 disposed on the sensor side of the aperture ST.

The radius of curvature of the seventh lens 107 may be larger than the radius of curvature of the sixth lens 106. The radius of curvature of the seventh lens 107 may be larger than the radius of curvature of the fifth and sixth lenses 105 and 106.

If the third lens 103 is designed as an aspherical surface, thermal compensation can be satisfied and optical performance can be improved, but assembly may not be easier than a spherical lens, and assembly of the aspherical third lens 103 may be difficult. Due to this, the optical characteristics of the lenses disposed closer to the sensor than the third lens 103 may be affected. If the third lens is a spherical lens, even if the third lens is affected by the optical characteristics, the radius of curvature of the third lens at the optical axis may not be significantly changed due to the spherical characteristics. In the present invention, the radius of curvature of the third lens 103 having an aspherical surface is designed to exceed 10 mm and the effective diameter is large, making assembly easy. In addition, when the radius of curvature at the optical axis is large, the shape of the lens is formed gently, Even if it is assembled slightly tilted from the optical axis, the effect on the sensors' lenses may be minimal.

In addition, the reason why the spherical first lens 101 has the second largest radius of curvature after the fourth lens 104 is that the lens disposed on the object side of the aperture ST is the lens most sensitive to optical characteristics. It provides a larger size or increases the thickness. Here, a sensitive lens means a lens that has a significant impact on the optical system even if the assembly is slightly wrong. Therefore, since the lens disposed on the object side of the aperture is the most sensitive to assembly, the curvature radius of the lenses adjacent to the aperture is designed to be largest, and the curvature radius of the first lens, which is sensitive to assembly, is increased.

Since the third lens 103 is provided as an aspherical surface, the radius of curvature at the optical axis does not increase, the difference in the radius of curvature between the object side surface and the sensor side surface does not increase, and heat compensation is possible by the glass material. , assembly can be improved by effective diameter and the influence on optical properties can be reduced.

The radius of curvature of the seventh lens 107 may be larger than the radius of curvature of the sixth lens 106 made of glass. Accordingly, the seventh lens 107 can guide light incident through the first to sixth lenses 101-106 to the entire area of the image sensor 300. When the radius of curvature of the seventh lens 117 is made larger than the radius of curvature of the sixth lens 116, assembly of the final aspherical lens can be improved and changes in optical characteristics can be minimized.

The radii of curvature of the first and second surfaces (S1 and S2) of the first lens 101 are defined as L1R1 and L1R2, and the radii of curvature of the 13th and 14th surfaces (S13 and S14) of the seventh lens 107 are defined as L1R1 and L1R2. are defined as L7R1 and L7R2, and the radii of curvature of each lens surface of the second to sixth lenses 102-106 are defined as L2R1, L2R2, L3R1, L3R2, L4R1, L4R2 (L5R1), L5R2, L6R1, and L6R2. It can be defined.

Condition 1: 0 < |L1R1/L1R2| < 1

Condition 2: 0.5 < |L2R1/L2R2| < 2

Condition 3: 0.2 < L3R1/L3R2 < 1.2

Condition 4: 0 < |L4R1/L4R2| < 0.5

Condition 5: 0 < |L5R1/L5R2| < 0.7

Condition 6: 1 < |L6R1/L6R2| < 2.5

Condition 7: 1.5 < L7R1/L7R2 < 4.5

Condition 8: 1mm ≤ |L3R2-L3R1| ≤10mm

Condition 9: 10mm < L7R1-L7R2 < 50mm

When the difference between the object-side radius of curvature and the sensor-side radius of curvature of the third lens 103 is provided within the above range, the assembling property of the third lens 103 having an aspherical surface is improved and the It can reduce optical effects.

When the center thickness of the first to seventh lenses 101-107 is defined as CT1-CT7 and the edge thickness of the first to seventh lenses 101-107 is defined as ET1-ET7, the first to seventh lenses 101-107 are defined as CT1-CT7. The sum of the center thicknesses of the seventh lenses 101-107 may be defined as ∑CT, and the sum of the edge thicknesses of the first to seventh lenses 101-107 may be defined as ∑ET.

To describe the thickness of the lenses, the central thickness (CT1) of the first lens 101 may be greater than the central thickness (CT2-CT7) of the second to seventh lenses (102-107), and the lens unit 100 ) can have a maximum thickness within. The central thickness (CT7) of the seventh lens 107 may be smaller than the central thickness (CT1-CT6) of the first to sixth lenses (101-106) and may have a minimum thickness within the lens unit 100. You can. The aspherical lens may include a third lens 103 and a seventh lens 107. The central thickness CT1 of the first lens 101 may be greater than 100% of the central thickness CT56 of the bonded lens 156, for example, in the range of 101% to 150%.

The following conditions can be satisfied.

Condition 1: 0.6 < CT1/ET1 < 1.3

Condition 2: 1 < CT2/ET2 < 2.5

Condition 3: 1 < CT3/ET3 < 2

Condition 4: 1.2 < CT4/ET4 < 2.5

Condition 5: 1.5 < CT5/ET5 < 3.5

Condition 6: 0 < CT6/ET6 < 1

Condition 7: 0.5 < CT7/ET7 < 1.2

Condition 8: 0.8 < ∑CT/∑ET < 1.2

Condition 9: 0.24 < CT1/∑CT < 0.44

In this way, the difference between the center thickness and edge thickness of each lens can be set to more than 0.6 mm and less than 4 mm. By arranging aspherical lenses in the third and seventh lenses 103 and 107, light can be effectively guided without increasing the difference between the center thickness and edge thickness of each lens. In addition, by setting the difference between the center thickness and the edge thickness of the third lens 103 to the range of condition 3, the difference in curvature radius between the object side surface and the sensor side surface can not be designed to be large, and the aspherical third lens 103 It can improve assembly efficiency and reduce the impact on optical properties.

Additionally, the difference between the maximum and minimum center thickness in the lenses may be 3 mm or more, for example, in the range of 3 mm to 8 mm or 3 mm to 7 mm. That is, even if the center thickness of the last aspherical lens is provided thin, optical performance may not deteriorate, and the camera module can be provided with a slim thickness. In addition, since the difference between the center thickness and edge thickness of each lens is not large, even if at least one lens is tilted, the impact on optical characteristics can be reduced. It can also reduce the influence on thermal characteristics between the center and edge of the lenses.

The maximum center thickness may be greater than the sum of the center thicknesses of two adjacent lenses. For example, the conditions: (CT2+CT3) < CT1, (CT3 + CT4) < CT1, (CT4 + CT5) < CT1, (CT5 + CT6) < CT1, and (CT6 + CT7) < CT1 may be satisfied.

The center spacing between the first to seventh lenses 101-107 can be defined as CG1-CG6, and the sum of the center spacings between the first to seventh lenses 101-107 can be defined as ∑CG. there is.

The center distance CG3 between the third lens 103 and the fourth lens 104 is the center distance between the aspherical lens and the spherical lens, and is the maximum within the lens unit 100, and the center distance between the spherical lenses. bigger than That is, the gap CG3 between the adjacent object-side aspherical lens and the sensor-side spherical lens may be maximum within the lens unit 100, and may be less than or equal to the center thickness of the bonded lens 156, for example, of the bonded lens 156. It may be at least 84% of the central thickness, such as in the range of 84% to 95%.

The center gap CG6 between the sixth lens 106 and the seventh lens 107 may be smaller than the center gap CG3 and may be the second largest within the lens unit 100 . That is, the gap (CG6) between the adjacent object-side spherical lens and the sensor-side aspherical lens can satisfy the condition of CT7 < CG6 < CG3 < CT1.

The center thickness of each lens and the center distance between adjacent lenses may satisfy the following conditions. (Here, the gap within the bonded lens is excluded)

Condition 1: 10 < CT1/CG1 < 30

Condition 2: 1 < CG6 / CT7 < 3

Condition 3: 1 < CG3/CT3 < 3

Condition 4: (CG6/CT7) < (CG3/CT3)

Condition 5: 0.2 < CG3/∑CG < 0.7

Condition 6: 1 < CT1/CG3 < 2

The maximum center thickness between lenses is 1.1 times or more, for example, 1.1 to 2 times the maximum center spacing, thereby providing a camera module with an aspherical lens applied in the optical system without increasing the center spacing compared to the center thickness of each lens. can do. In condition 3, since the aspherical third lens 103 is provided in a meniscus shape convex toward the object, a large gap between the third and fourth lenses 104 and 105 can be provided.

Here, if the ith center spacing between two adjacent lenses is defined as CGi, and the center thickness of the ith lens disposed on the object side than the CGi is defined as CTi, the following conditions can be satisfied (where , excluding bonded lenses and the gap between bonded lenses).

The ratio of CTi/CGi may be maximum when i is 1 and minimum when i is 3. The reason why the value of CTi/CGi is minimum when i is 3 can be implemented by the third lens 103 made of aspherical glass.

When the optical axis distance from the center of the object-side surface of the first lens 101 to the surface of the image sensor 300 is TTL, the following conditions can be satisfied.

Condition 1: 0 < CT1/TTL < 0.5

Preferably, Condition 1 may satisfy 0.18 ≤ CT1/TTL ≤ 0.3. Since the first lens 101 is a spherical lens made of glass, an optical system that can satisfy thermal compensation according to temperature changes can be designed by having a thick first lens 101 that satisfies condition 1. In other words, condition 1 may be a characteristic that appears when the first lens 101 is designed as spherical glass.

Condition 2: 0.1 < CT2/TTL < 0.5

Condition 3: 0 < CT3/TTL < 0.1

Condition 4: 0 < CT4/TTL < 0.1

Condition 5: 0 < CT5/TTL < 0.15

Condition 6: 0 < CT6/TTL < 0.1

Condition 7: 0 < CT7/TTL < 0.1

The ratio of CT1/TTL in condition 1 may be greater than the values in conditions 2 to 7.

When explaining the effective diameter, the lens with the maximum effective diameter may be the fourth lens 104 that is closest to the object. The fourth lens 104 having the maximum effective diameter may be a spherical lens. The lens with the minimum effective diameter may be the lens closest to the image sensor 300, for example, the seventh lens 107. The fourth lens 104 having the maximum effective diameter may be disposed between the aspherical third lens 103 and the bonded lens 156.

The effective diameters of the first lens 101 to the seventh lens 107 can be defined as CA1, CA2, CA3, CA4, CA5, CA6, and CA7, and the first and second surfaces of the first lens 101 ( The effective diameters of S1 and S2) can be defined as CA11 and CA12, and the effective diameters of the 13th and 14th surfaces (S13 and S14) of the seventh lens 107 can be defined as CA71 and CA72. The effective diameters of the object side and sensor side of the sixth lens can be defined as CA21, CA22, CA31, CA32, CA41, CA42, CA51, CA52, CA61, and CA62.

The effective diameter can satisfy the following conditions.

Condition 1: CA11 < CA21 < CA22

Condition 2: CA71 < CA72

Condition 3: CA22 < CA31 < CA41

Condition 4: (CA11-CA12) < (CA61-CA62)

Condition 5: CA71 < CA61 < CA51 < CA41

Condition 5: CA1 < CA2 < CA3 < CA4

Condition 6: CA4 > CA5 > CA6 > (2*Imgh) > CA7

As in condition 1, even if the effective diameter of the first lens 101 is smaller than that of the second lens 102, heat compensation can be more effective and assembly efficiency can be improved due to the spherical glass material and thick thickness. You can.

When explaining the refractive index, the refractive index of at least one of the first and third lenses 101 and 103 is the maximum among the lenses. Preferably, the refractive index of the first lens 101 may be the maximum and may be 1.72 or more. The difference in refractive index between the first and third lenses 101 and 103 is 0.10 or less. The refractive index of the fourth lens 104 is the smallest among the lenses. The difference between the maximum and minimum refractive indices may be 0.20 or more. By adjusting the refractive index of the spherical lens and the aspherical lens, incident efficiency can be increased and the incident light can be guided to the image sensor 300.

Explaining the Abbe number, the Abbe number of the fourth lens 104 is the largest among lenses and may be 65 or more. The Abbe number of the first lens 101 is the smallest among the lenses. The difference between the maximum refractive index and the minimum Abbe number may be 30 or more. By reducing the Abbe number of the object-side lens of the aperture (ST), increasing the Abbe number of the sensor-side lens, and providing a small Abbe number of the aspherical seventh lens 107 closest to the image sensor 300, glass It is possible to adjust the color dispersion of light traveling between lenses of material and guide it to the image sensor 300 by increasing the color dispersion between the spherical lens and the aspherical lens.

If the effective diameter average of a spherical lens is GL_CA_Aver, and the effective diameter average of an aspherical lens is GM_CA_Aver, the condition of GM_CA_Aver < GL_CA_Aver can be satisfied.

If the average of the center thickness of a spherical lens is GL_CT_Aver, and the average of the center thickness of an aspherical lens is GM_CT_Aver, the condition of GM_CT_Aver < GL_CT_Aver can be satisfied.

If the average refractive index of a spherical lens is GL_nd_Aver, and the average refractive index of an aspherical lens is GM_nd_Aver, the condition of GL_nd_Aver < GM_nd_Aver can be satisfied.

If the average Abbe number of a spherical lens is GL_Ad_Aver, and the average Abbe number of an aspherical lens is GM_Ad_Aver, the condition of GM_Ad_Aver < GL_Ad_Aver can be satisfied.

The focal lengths F1, F6, and F7 of the first, sixth, and seventh lenses (101, 106, and 107) have negative refractive power, and the focal lengths (F2, F3, and F4) of the second, third, and fifth lenses (102, 103, 104, and 105) have negative refractive power. ,F5) may have positive refractive power.

Additionally, the fifth and sixth lenses 105 and 106, which are adjacent lenses, may satisfy the following conditions.

Condition 1: Refractive index of a lens with positive refractive power < Refractive index of a lens with negative refractive power

Condition 2: Dispersion value of a lens with positive refractive power > Dispersion value of a lens with negative refractive power

Here, the fifth lens 105 has positive refractive power and the sixth lens 106 has negative refractive power, and as in Conditions 1 and 2, the refractive index of the fifth lens 105 is equal to the sixth lens 106. ), and the dispersion value of the fifth lens 105 is greater than the dispersion value of the sixth lens 106. Accordingly, chromatic aberration occurring in a spherical lens can be corrected with an aspherical lens. In addition, by satisfying the refractive index difference between the 5th and 6th lenses (105, 106) arranged in succession from 0.01 to 0.15 and the Abbe number difference from 20 to 60, chromatic aberration occurring in the spherical lens can be compensated with a bonded lens. there is. Here, the refractive index difference is rounded to the third decimal place, and the Abbe number difference is rounded to the first decimal place to compare values.

The optical system 1000 generates chromatic aberration, and the chromatic aberration is corrected using a bonded lens 156 or two lenses arranged in series. As the temperature changes from low to high, the lens repeats contraction and expansion. Since lenses made of the same material have the same amount of change in lens characteristics due to temperature changes, it is effective to correct chromatic aberration between lenses made of the same material even if the temperature changes.

In addition, the third lens 103 and the seventh lens 107 are used to correct chromatic aberration occurring in the spherical lens, and the sixth lens 106 and the seventh lens 107 are used to correct the spherical lens. Chromatic aberration between and aspherical lenses can be mutually corrected.

In addition, by arranging glass lenses with a relatively high Abbe number of the fifth lens 105 of the bonded lens 156 disposed on the object side of the aspherical seventh lens 107, chromatic dispersion is reduced by the glass lenses, Aspherical lenses can increase color dispersion.

If the focal length is expressed as an absolute value, the focal length of the third lens 103 is the largest among the lenses and may be 45 or more. The focal length of the sixth lens 106 is the smallest among the lenses. The difference between the maximum and minimum focus distances may be 35 or more. By providing the largest focal length of the object-side aspherical third lens 103 and the smallest focal length of the sixth lens 106 adjacent to the last aspherical lens, improved MTF characteristics and aberration control characteristics in the field of view range set in the optical system , resolution characteristics, etc., and can have good optical performance in the peripheral part of the angle of view.

The sensor side of the seventh lens 107 has a critical point. The critical point is the point at which the trend of the Sag value changes. In other words, it is the point where the Sag value increases and then decreases, or the point where the Sag value decreases and then increases. It can be seen that the sensor side of the seventh lens 107 has a critical point between a point of 3.5 mm and a point of 4.4 mm in a direction perpendicular to the optical axis based on the optical axis. For example, the Sag value of the sensor side of the seventh lens 107 increases in a direction perpendicular to the optical axis to a critical point, and then decreases toward the edge after the critical point. If a critical point exists on the sensor side of the seventh lens 107, that is, the sensor side of the last lens, that is, the lens side closest to the sensor, the TTL can be reduced, making it easy to miniaturize and lighten the optical system.

In Figure 2, Sag51 represents the Sag value of the object-side surface of the fifth lens 105, Sag62 represents the Sag value of the sensor-side surface of the sixth lens 106, and Sag72 represents the Sag value of the sensor-side surface of the seventh lens 105. It represents the Sag value, and the Sag value of the object side of the seventh lens can be expressed as Sag71. The Sag value has a positive value when the lens surface is located closer to the sensor than the center of each lens surface, and has a negative value when it is located closer to the object than the center of each lens surface.

As shown in FIG. 4 , in the embodiment, the lens surfaces of the third and seventh lenses 103 and 107 of the lens unit 100 may include an aspherical surface with a 30th order aspherical coefficient. For example, the third and seventh lenses 103 and 107 may include lens surfaces having a 30th order aspherical coefficient. As described above, an aspheric surface with a 30th order aspheric coefficient (a value other than “0”) can particularly significantly change the aspherical shape of the peripheral area, so the optical performance of the peripheral area of the field of view (FOV) can be well corrected.

As shown in Figure 5, the thickness (T1-T7) of the first to seventh lenses (101, 102, 103, 104, 105, 106, and 107) and the gap (G1-G6) between two adjacent lenses can be set. As shown in Figure 5, in the Y-axis direction, the thickness of each lens (T1-T7) can be expressed at intervals of 0.1mm or 0.2mm or more, and the interval between each lens (G1-G6) can be expressed at intervals of 0.1mm or 0.2mm or more. It can be displayed every time.

The center thickness (CT56) of the bonded lens 156 may be greater than the edge thickness (ET56). The central thickness (CT56) of the bonded lens 156 is the distance from the center of the object-side ninth surface (S9) of the fifth lens 105 to the center of the twelfth surface (S12) of the sixth lens 106, The edge thickness ET56 is the distance from the end of the effective area of the ninth surface S9 to the twelfth surface S12 in the optical axis direction. The maximum thickness of the bonded lens 156 is at the center, the minimum thickness is at the edge, and the maximum thickness may be at least 1 time the minimum thickness, for example, in the range of 1 to 1.5 times. The bonded lens 156 can satisfy the condition of 0mm < CT56-ET56 < 2mm.

As shown in FIG. 6 , the chief ray angle (CRA) in the optical system and camera module of FIG. 1 may be 10 degrees or more, for example, in the range of 10 degrees to 35 degrees or in the range of 10 degrees to 25 degrees. 13 is a graph showing the peripheral light ratio or relative illumination according to the image height in the optical system according to the embodiment, where the peripheral light ratio is 70% or more, for example, 75% or more from the center of the image sensor to the end of the diagonal. You can see that it appears. In other words, it can be seen that there is almost no difference in ambient illuminance (Zoom positions 1, 2, 3) depending on temperature up to 4.4mm from the optical axis.

7 to 9 are graphs showing diffraction MTF (modulation transfer function) at room temperature, low temperature, and high temperature in the optical system of FIG. 1, and are graphs showing luminance ratio (modulation) according to spatial frequency. . 7 to 9, in an embodiment of the invention, the deviation of MTF from low or high temperature based on room temperature may be less than 10%, that is, 7% or less.

Figures 10 to 12 are graphs showing aberration characteristics at room temperature, low temperature, and high temperature in the optical system of Figure 1. 10 to 12 are graphs measuring spherical aberration, astigmatic field curves, and distortion from left to right. 10 to 12, the X-axis may represent focal length (mm) and distortion (%), and the Y-axis may represent the height of the image. In addition, the graph for spherical aberration is a graph for light in the wavelength band of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for astigmatism and distortion is a graph for light in the wavelength band of about 546 nm. . In the aberration diagrams of FIGS. 10 to 12, it can be interpreted that the closer each curve at room temperature, low temperature, and high temperature is to the Y-axis, the better the aberration correction function is. The optical system 1000 according to the embodiment has an aberration correction function in most areas. You can see that the measured values are adjacent to the Y axis. That is, the optical system 1000 according to the embodiment has improved resolution and can have good optical performance not only in the center but also in the periphery of the field of view (FOV). 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 to 27 degrees, and the high temperature is 85 degrees or higher, for example, in the range of 85 to 105 degrees. It can be. Accordingly, it can be seen that the decrease in luminance ratio (modulation) from the low temperature to the high temperature in FIGS. 10 to 12 is less than 10%, for example, 5% or less, or is almost unchanged.

Table 1 compares the changes in optical properties such as EFL, BFL, F number, TTL, and FOV at room temperature, low temperature, and high temperature in the optical system according to the embodiment, and the change rate of optical properties at low temperature based on room temperature is 5% or less, e.g. , it can be seen that it appears to be less than 3%, and the change rate of optical properties at low temperatures based on room temperature is less than 5%, for example, less than 3%.

room temperature low temperature High temperature Low temperature/room temperature High temperature/room temperature EFL(F) 15.1 15.1 15.2 99.89% 100.14% BFL 3.2 3.2 3.2 99.88% 100.14% F# 1.6 1.59 1.6 99.89% 100.15% TTL 36.7 36.6 36.7 99.92% 100.10% FOV 34.3 34.3 34.2 100.11% 99.86%

Therefore, as shown in Table 1, the change in optical properties according to the temperature change from low to high temperature, for example, the rate of change in effective focal length (EFL), TTL, BFL, F number, and diagonal angle of view (FOV) is less than 10%, that is, , 5% or less, for example, it can be seen that it is in the range of 0 to 5%. Even if at least one or two aspherical lenses are used, temperature compensation for the aspherical lenses is designed to prevent deterioration in the reliability of optical characteristics. In this way, since the third lens 103 and the seventh lens 107 are made of an aspherical glass material, it can be seen that thermal compensation is possible according to temperature changes from low to high temperatures in the entire optical system, and these lenses It can be seen that the optical properties are not affected due to the assembling process.

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

The optical system 1000 according to the embodiment disclosed above may satisfy at least one or two of the equations described below. Accordingly, the optical system 1000 according to the embodiment may have improved optical characteristics. For example, when the optical system 1000 satisfies at least one mathematical equation, the optical system 1000 can effectively control aberration characteristics such as chromatic aberration and distortion aberration, not only in the center but also in the periphery of the field of view (FOV). It can have good optical performance. Additionally, the optical system 1000 may have improved resolution. In addition, the meaning of the thickness of the lens at the optical axis (OA) and the distance between the adjacent lenses at the optical axis (OA) described in the equations may refer to the embodiment disclosed above.

[Equation 1]

1 < CT1 / CT2 < 5

In Equation 1, CT1 refers to the central thickness of the first lens 101, and CT2 refers to the thickness (mm) of the second lens 102 at the optical axis (OA). Equation 1 sets the difference in the center thickness of the first and second lenses, thereby improving the chromatic aberration of the optical system. Equation 1 may satisfy 3 < CT1 / CT2 < 4 in the embodiment. By setting the central thickness of the spherical first and second lenses 101 and 102, optical performance in the center and periphery of the field of view (FOV) can be improved.

[Equation 2]

(CT7*CA7) < (CT1*CA1)

CT7 is the central thickness of the seventh lens 107, CA1 is the effective diameter of the first lens 101, and CA7 is the effective diameter of the seventh lens. The effective diameter is the average of the effective diameters of the object side and sensor side of the first and seventh lenses. Preferably, the conditions CT7 < CT1 and CA7 < CA1 may be satisfied. By setting the thickness and effective diameter of the first and seventh lenses, the optical system can improve spherical aberration. In addition, heat compensation is possible by the central thickness and effective diameter of the first lens 101 made of glass according to Equation 2, and the influence on optical characteristics can be reduced.

[Equation 3]

Po1 < 0

In Equation 3, Po1 represents the refractive power of the first lens 101, and can be set to have a shorter effective focal length (F) compared to TTL in the optical system for the performance of the optical system. Accordingly, TTL > F may be satisfied, and for example, TTL may be in the range of 1.5 times or more, for example, 1.5 to 3 times the effective focal length (F).

[Equation 4]

1.7 < n3 < 2.2

N3 is the refractive index at the d-line of the third lens 103. Equation 4 sets the refractive index of the third lens high, so that factors affecting the reduction of third-order aberration (Seidel aberration) of the optical system can be adjusted, and aberrations that may occur as the TTL becomes somewhat longer can be reduced. Equation 4 preferably satisfies 1.72 < n3 < 1.90. If designed lower than the lower limit of Equation 4, performance can be achieved by reducing aberration, and the refractive power of the third lens 103 is weakened and light cannot be collected efficiently, which may deteriorate the performance of the optical system. If it is designed to be higher than the upper limit of Equation 4 above, there is a disadvantage in that it becomes difficult to obtain materials. In addition, if the refractive index of the third lens 103 is designed to be lower than the lower limit of Equation 4, the radius of curvature of the fifth and sixth lenses must be increased to increase the refractive power of the fifth and sixth lenses, and in this case, the lens manufacturing This becomes more difficult, the lens defect rate increases, and yield may decrease.

[Equation 4-1]

1.60 ≤ Aver(n1:n7) ≤ 1.70

In Equation 4-1, Aver(n1:n7) is the average of the refractive index values in the d-line of the first to seventh lenses. When the optical system 1000 according to the embodiment satisfies Equation 4-1, the optical system 1000 can set the resolution and suppress the influence on TTL.

[Equation 4-2]

0.5 < GL_nd_Aver/GM_nd_Aver < 1.5

GL_nd_Aver is the average refractive index of the spherical lenses in the lens unit 100, and GM_nd_Aver is the average refractive index of the aspherical lenses. The fifth to seventh lenses with high refractive index are located on the sensor side to increase color dispersion. Preferably, Equation 4-2 may satisfy 0.7 < GL_nd_Aver/GM_nd_Aver < 1.

[Equation 5]

20 < FOV_H < 40

In Equation 5, FOV_H represents the horizontal angle of view, and the range of the vehicle optical system can be set. Equation 5 preferably satisfies 25 ≤ FOV_H ≤ 35 or satisfies the range of 30 degrees ± 3 degrees, and in this case, the sensor length in the horizontal direction can be based on 8.064 mm ± 0.5 mm. Additionally, when Equation 5 is satisfied, when the temperature changes from room temperature to high, the rate of change of the effective focal distance and the change rate of the angle of view can be set to 5% or less, for example, 0 to 5%. In addition, even if one or more aspherical lenses are mixed with spherical lenses, for example, two or more aspherical lenses are used in the optical system 1000, degradation of optical characteristics can be prevented through temperature compensation of the glass lens.

[Equation 6]

L1R1 < 0

L1R1 represents the radius of curvature of the first surface S1 of the first lens 101 and may be set to be less than 0. If Equation 6 is satisfied, the shape of the optical system can be limited. The object-side surface of the first lens 101 is concave to prevent surface damage when it comes into contact with an external structure. Additionally, since the condition L1R1*L1R2 > 0 is satisfied, incident light can be refracted in a direction away from the optical axis. Accordingly, the embodiment can reduce the center distance between the first and second lenses 101 and 102, and the effective diameter of the second lens 102 can be provided larger than the effective diameter of the first lens 101.

[Equation 6-1]

L3R1 > 0

L2R2 < 0

L3R1 is the radius of curvature of the object-side surface of the third lens 103, and L2R2 is the radius of curvature of the sensor-side surface of the second lens. Since the first lens 101 has a meniscus shape that is convex toward the sensor, it can refract light up to the edge portions of the second and third lenses with large effective diameters. Since the first lens has a meniscus shape that is convex toward the sensor, it can refract the edges of the second and third lenses with large effective diameters and reduce the number of lenses. In addition, since the conditions L3R2 > L3R1 and |L4R1 < L4R2 | are satisfied, light can be adjusted so as not to increase the effective diameter of the fifth to seventh lenses, and TTL can be reduced. If the condition is L3R1 > L3R2, there is a problem in which aberration occurs between the object-side surfaces of the first lens and the second lens, the effective diameter of the sensor-side lenses increases, or the TTL increases. By setting the curvature radii of the first, second, and fourth lenses 101, 102, and 104 to be large, the influence of optical characteristics on incident light can be reduced.

[Equation 7]

0.8 < BFL/L7S2_max_sag to Sensor < 3

BFL is the optical axis distance from the center of the sensor side of the last lens, that is, the seventh lens, to the surface of the image sensor. L7S2_max_sag to Sensor may be the distance in the optical axis direction from the maximum Sag value of the seventh lens 107 to the image sensor 300. If the optical system satisfies Equation 7, TTL can be reduced and conditions for manufacturing a camera module can be set. Additionally, L7S2_max_sag to Sensor can set a space where the optical filter 500 and the cover glass 400 located between the image sensor 300 and the seventh lens 107 can be placed. If the range of Equation 7 is smaller than the lower limit, the space for placing circuit structures such as optical filters and image sensors becomes limited, making the process of assembling circuit structures such as filters and image sensors into the optical system difficult. If the range of Equation 7 is larger than the upper limit, the process of assembling circuit structures such as filters and image sensors into the optical system is easy, but the TTL becomes longer, making miniaturization of the optical system difficult. That is, Equation 7 can set the minimum distance between the image sensor 300 and the last lens, and preferably satisfies the condition L7S2_max_sag to Sensor < BFL. Additionally, if there is no point where the last lens protrudes further in the direction of the image sensor than the center of the sensor side, the value of Equation 6 may be equal to the back focal length (BFL). The BFL is the optical axis distance from the image sensor 300 to the center of the sensor side of the last lens. In detail, if 1 < BFL/L7S2_max_sag to Sensor < 1.2 is satisfied, it is easier to manufacture and reduce TTL.

[Equation 8]

3 < CT1 / CT7 < 7

If Equation 8 is satisfied, the aberration characteristics can be improved and the influence on the reduction of the optical system can be set. Equation 8 preferably satisfies 4 < CT1 / CT7 < 5.5. Equation 8 sets the central thickness of the first lens on the object side of the optical system and the seventh lens having an aspherical surface, and can limit the difference in central thickness between them. Accordingly, chromatic aberration of the optical system can be improved, good optical performance can be achieved at a set angle of view, and TTL (total track length) can be controlled.

[Equation 8-1]

0.4 < CT1/CA11 < 1

In Equation 8-1, the center thickness (CT1) of the first lens 101 and the effective diameter (CA11) of the object side surface (S1) of the first lens 101 can be set. If these are satisfied, the glass material Deterioration of the strength and optical properties of the lens can be prevented. If it is lower than the range of Equation 8-1, the lens may be damaged or injection molding is difficult, and if it is larger than the above range, the TTL may increase and the weight of the optical system may become heavy. Preferably, 0.5 < CT1/CA11 < 0.8 may be satisfied.

[Equation 8-2]

0.4 < CT1/CA41 < 1

In Equation 8-2, the center thickness (CT1) of the first lens 101 and the effective diameter (CA41) of the object side surface (S7) of the fourth lens 104 can be set. If this is satisfied, the maximum center thickness A lens with and a lens with the maximum effective diameter can be set. Preferably, 0.5 < CT1/CA41 < 0.7 may be satisfied.

[Equation 9]

0 < CT3 / CT7 < 3

CT3 is the central thickness of the third lens 103, and CT7 is the central thickness of the seventh lens 107. If the optical system satisfies Equation 9, the ratio of the center thickness of the aspherical lens can be set, the aberration characteristics can be improved, and the influence on the reduction of the optical system can be set. Equation 9 may preferably satisfy 1.2 < CT3 / CT7 < 1.9.

[Equation 10]

1 < CT56 / CT7 < 5

In Equation 10, CT56 is the sum of the center thicknesses of the fifth and sixth lenses, for example, the center thickness of the bonded lens 156. That is, CT56 is the optical axis distance from the center of the object-side surface of the fifth lens 105 to the center of the sensor-side surface of the sixth lens 106. If the optical system satisfies Equation 10, the center thickness of the bonded lens and the seventh lens 107 adjacent to it can be set to improve aberration characteristics, and preferably 3 < CT56 / CT7 < 4. Here, the condition CT56 > ET56 can be satisfied, where ET56 is the edge thickness of the bonded lens.

[Equation 11]

0 < |L2R1 / L4R2| < 1

In Equation 11, L2R1 refers to the radius of curvature of the first surface (S1) of the second lens 102, and L4R2 refers to the radius of curvature of the eighth surface (S8) of the fourth lens 104. When the optical system 1000 according to the embodiment satisfies Equation 11, the aberration characteristics of the optical system 1000 may be improved. Preferably, 0 < |L2R1 / L4R2| < 0.5 can be satisfied.

[Equation 12]

0 < CT56 - ET56 < 2mm

In Equation 12, ET56 is the optical axis distance from the end of the effective area of the object-side surface of the fifth lens 105 to the end of the effective area of the sensor-side surface of the sixth lens 106. If the optical system satisfies Equation 12, the aberration characteristics can be improved by setting the center thickness and edge thickness of the bonded lens, and preferably the condition of CT56 < CT1 can be satisfied. Additionally, the condition ET56 < ET1 can be satisfied.

[Equation 13]

0 < CA11 / CA31 < 2

In Equation 13, CA11 refers to the effective diameter of the first surface (S1) of the first lens 101, and CA31 refers to the effective diameter of the fifth surface (S5) of the third lens 103. If Equation 13 is satisfied, the optical system 1000 can control incident light and set factors affecting aberration. Preferably, 0.5 < CA11 / CA31 < 1 can be satisfied. Since the first and third lenses satisfy Equation 13, the difference in effective diameter between the first and third lenses is not large, which can reduce the effect of assembling and reduce the optical effect of temperature changes.

[Equation 14]

0 < CA72 / CA42 < 2

In Equation 14, CA42 refers to the effective diameter of the eighth surface (S8) of the fourth lens 104, and CA72 refers to the effective diameter of the fourteenth surface (S14) of the seventh lens 107. If Equation 14 is satisfied, the optical system 1000 can control the incident light path and set factors for performance change according to CRA and temperature. Preferably, Equation 14 may satisfy 0.5 < CA72 / CA42 < 1.0.

[Equation 15]

0 < CA12 / CA21 < 2

In Equation 15, CA12 refers to the effective diameter of the second surface (S2) of the first lens 101, and CA21 refers to the effective diameter of the third surface (S3) of the second lens 102. When the optical system 1000 according to the embodiment satisfies Equation 15, the optical system 1000 can control light traveling to the first lens group (LG1) and the second lens group (LG2), and lens sensitivity is reduced. You can set factors that affect . Equation 15 may preferably satisfy 0.5 < CA12 / CA21 < 1.

Since the first and second lenses satisfy Equation 15, the influence on optical characteristics due to assembling and tilt can be suppressed by the curvature radius and effective diameter of the first and second lenses, and heat compensation can be possible. there is.

[Equation 16]

0 < CA31 / CA42 < 2

CA31 refers to the effective diameter of the fifth surface (S5) of the third lens 103, and CA42 refers to the effective diameter of the eighth surface (S8) of the fourth lens 104. If the optical system 1000 according to the embodiment satisfies Equation 16, the sizes of the aspherical lens and the spherical lens can be set. Equation 16 may preferably satisfy 0.5 < CA31 / CA42 < 1.0.

[Equation 17]

0 < CA51 / CA62 < 2

CA51 refers to the effective diameter of the ninth surface (S9) of the fifth lens 105, and CA62 refers to the effective diameter of the twelfth surface (S12) of the sixth lens 106. When the optical system 1000 according to the embodiment satisfies Equation 17, the optical system 1000 can improve chromatic aberration and set the size between the object side and the sensor side within the bonded lens 156. there is. Accordingly, by setting the effective diameter size of the bonded lens disposed closer to the object than the last aspherical lens, light incident through the bonded lens can be effectively guided to the aspherical lens. Equation 17 may preferably satisfy 1 < CA51 / CA62 < 1.6.

Since the bonded lens satisfies Equation 17, the TTL within the optical system can be reduced, the effective diameter of the lenses placed on the sensor side of the bonded lens can be reduced, and a camera module with a slimmer thickness can be provided. there is.

[Equation 18]

0 < CA62 / CA71 < 2

CA71 refers to the effective diameter of the 13th surface (S13) of the seventh lens 107. When the optical system 1000 according to the embodiment satisfies Equation 18, a relationship can be established between the effective diameter of the sensor-side surface of the bonded lens 156 and the effective diameter of the object-side surface of the lens adjacent thereto. Accordingly, the optical system 1000 can improve chromatic aberration and set the size and radius of curvature between the sensor-side surfaces of the sensor-side sixth lens within the bonded lens. Accordingly, the effective diameter size of the fifth and sixth lenses arranged on the object side than the last lens can be set. Equation 18 may preferably satisfy 1 < CA62 / CA71 < 1.2.

[Equation 18-1]

1mm < (CA61 - CA62) < 3mm

In Equation 18-1, the effective diameter difference between the object-side surface and the sensor-side surface (S12) of the sixth lens may exceed 1 mm, and may be larger than the effective diameter difference between the object-side surface and the sensor-side surface of other lenses, and the optical system It may be the largest difference in effective diameter between the object side and the sensor side of each lens. Accordingly, by maximizing the difference in effective diameter between the object-side surface and the sensor-side surface of the sixth lens, which is a spherical lens adjacent to the aspherical lens, the light refracted through the sixth lens can proceed into the effective area of the aspherical lens.

[Equation 18-2] CA4 > CA5 > CA6

[Equation 18-3] CA41 > (ImgH*2)

[Equation 18-4] CA51 > (ImgH*2)

[Equation 18-5] CA62 > (ImgH*2)

In Equations 18-2 to 18-5, CA5 is the effective diameter of the fifth lens 105, CA6 is the effective diameter of the sixth lens 106, ImgH is 1/2 of the diagonal length of the image sensor 300, CA62 is the effective diameter of the sensor side of the sixth lens. Accordingly, an optical path is set to the area of the image sensor 300 based on the effective diameter of the fifth lens 105, the effective diameter of the object-side surface of the fourth lens 104, and the effective diameter of the object-side surface of the fifth lens 105. I can give it. In the embodiment, the nth lens is provided as an aspherical lens, so the effective diameter ratio of the adjacent spherical lens and the bonded lens can satisfy Equations 18 to 18-5.

[Equation 19]

0.2 < GL_CA_Aver/GM_CA_Aver < 2

In Equation 19, GL_CA_Aver represents the average effective diameter of glass lenses having a spherical surface, and GM_CA_Aver represents the average effective diameter of glass mold lenses having an aspherical surface. By setting the effective diameters of the spherical lens and the aspherical lens in Equation 19, the path of incident light can be effectively guided. Equation 19 may preferably satisfy 1 < GL_CA_Aver/GM_CA_Aver < 1.2. In other words, the difference in effective diameter between the spherical lens and the aspherical lens can be set to be not large.

Here, nGL > nGM can be satisfied. The nGL is the number of spherical glass lenses, and nGM is the number of aspherical glass lenses. In the embodiment, by adding an aspherical lens, the number of lenses can be reduced and optical characteristics can be prevented from being deteriorated.

[Equation 20]

0 < GL_nd_Aver/GM_nd_Aver < 1.60

In Equation 19, GL_nd_Aver is the average refractive index of glass lenses, for example, the average refractive index of the first, second, fourth, fifth, and sixth lenses. GM_nd_Aver is the average refractive index of the 3rd and 7th lenses. Preferably, the refractive index of the spherical lens and the refractive index of the aspherical lens can be set to satisfy the condition of 0.7 < GL_nd_Aver/GM_nd_Aver < 1.

[Equation 20-1]

0 < ΣGM_nd / ΣGL_nd < 1

ΣGM_nd is the sum of the refractive indices of the glass mold lens, and ΣGL_nd is the sum of the refractive indices of the spherical glass lens. Preferably, 0.2 < ΣGM_nd / ΣGL_nd < 0.6 may be satisfied. The optical system can control resolution and color dispersion by setting the difference in refractive index between spherical lenses and aspherical lenses.

[Equation 21]

CA6 or CA7 < CA5

In Equation 21, CA6 represents the effective diameter of the sixth lens 106, CA7 represents the effective diameter of the seventh lens 107, and CA5 represents the effective diameter of the fifth lens. If Equation 21 is satisfied, the optical system sets the effective diameter of the sixth and seventh lenses disposed between the fifth lens 105 and the image sensor 300 to be smaller than the effective diameter of the fifth lens 105, so that the image sensor Light can be guided to the center and periphery of (300) and chromatic aberration can be improved.

[Equation 22]

CG2 < CG6 < CG3

In Equation 22, CG2 is the center spacing between the 2nd and 3rd lenses, CG3 is the center spacing between the 3rd and 4th lenses, and CG6 is the center spacing between the 6th and 7th lenses. If Equation 22 is satisfied, the center spacing from the second lens to the seventh lens can be set, thereby reducing the center spacing and improving the optical performance of the peripheral part of the field of view (FOV).

[Equation 22-1]

G5 < 0.01 or CG5 < 0.01

In Equation 22-1, G5 and CG5 are the distance between the fifth lens 105 and the sixth lens 106 and the center distance. If Equation 22-1 is satisfied, the 5th and 6th lenses can be set as bonded lenses. Here, preferably, CT56 = CT5 + CT6 + CG5 can be satisfied, and can be obtained as the sum of the center thicknesses (CT5, CT6) of the fifth and sixth lenses and the center spacing (CG5) of the fifth and sixth lenses.

[Equation 23]

0 < CT7 / CG6 < 1

In Equation 23, CG6 is the center distance between the sensor-side surface of the sixth lens 106 and the object-side surface of the seventh lens 107. In Equation 23, by setting the center thickness (CT7) of the seventh lens 107 and the center distance between the sixth and seventh lenses, optical performance can be improved at the periphery of the angle of view. Equation 23 may preferably satisfy 0.2 < CT7/CG6 < 0.8.

[Equation 24]

LD34 < LD12

LD12 is the optical axis distance from the object side of the first lens to the sensor side of the second lens, and LD34 is the optical axis distance from the object side of the third lens to the sensor side of the fourth lens. If Equation 24 is satisfied, incident light can be guided to the effective area of the aspherical lens and TTL can be reduced.

[Equation 25]

CG57 < CG14

CG14 represents the sum of center spacings between the first to fourth lenses, and CG46 represents the sum of center spacings between the fifth to seventh lenses. If Equation 25 is satisfied, the incident light can be guided to the aspherical lens by adjusting the center distance between the lenses located on the object side than the bonded lens and the center distance from the bonded lens to the last lens, improving chromatic aberration, TTL can be reduced. Equation 25 can be satisfied by the aspherical lens of the third lens 103.

[Equation 26]

1 < CT6/CT7 < 3

In Equation 26, by setting the center thickness (CT6) of the sixth lens to be thicker than the center thickness (CT7) of the seventh lens, factors affecting aberration can be controlled. Preferably, Equation 26 may satisfy 1 < CT6/CT7 < 1.5.

[Equation 27]

10 < L7R1 / CT7 < 40

In Equation 27, L7R1 means the radius of curvature of the 13th surface of the 7th lens. In Equation 27, the refractive power of the seventh lens can be controlled by setting the radius of curvature of the object-side surface of the seventh lens and the central thickness of the seventh lens. Accordingly, good optical performance can be achieved in the center and periphery of the angle of view. Preferably, Equation 27 can satisfy 18 < L7R1 / CT7 < 30. By adjusting the radius of curvature and center thickness of the seventh lens having an aspherical surface using Equation 27, the TTL of the optical system can be reduced and degradation of optical performance can be prevented.

[Equation 28]

0 < |L5R2/L7R1| < 10

In Equation 28, L5R2 means the radius of curvature of the 10th surface of the 5th lens. In Equation 28, the radius of curvature of the sensor-side surface of the fifth lens and the radius of curvature of the object-side surface of the seventh lens can be set to control the refractive power of the fifth and seventh lenses. Accordingly, good optical performance can be achieved in the center and periphery of the angle of view. Preferably, equation 28 satisfies 0 < |L5R2 / L7R1| < 1 can be satisfied.

[Equation 29]

L1R1*L1R2 > 0

In Equation 29, L1R1 is the radius of curvature of the object-side surface of the first lens, and L1R2 is the radius of curvature of the sensor-side surface of the first lens. If Equation 29 is satisfied, the refractive power of the first lens can be controlled and the incident light can be controlled by the spherical lens. Preferably, L1R1+L1R2 < 0 may be satisfied. By setting the radius of curvature of the first lens according to Equation 29, it is possible to prevent deterioration of assembly of the spherical lens and set the gap between the first and second lenses.

[Equation 30]

0 < |L5R1/L6R2| < 2

L5R1 is the radius of curvature of the object-side surface of the fifth lens, and L6R2 is the radius of curvature of the sensor-side surface of the sixth lens. If Equation 30 is satisfied, the fourth and fifth lenses can be expressed as a bonded lens. The radius of curvature of the interface between the fifth lens and the sixth lens is the same and, for example, may satisfy L6R1/L5R2 = 1.

[Equation 31]

0 < |L6R2/L6R1| < 2

L6R1 refers to the radius of curvature of the object-side surface of the sixth lens, and L6R2 refers to the radius of curvature of the sensor-side surface of the sixth lens. By setting the radius of curvature of the object-side surface and the sensor-side surface of the sixth lens in Equation 31, light can be effectively refracted from the bonded lens toward the aspherical lens. Equation 31 preferably states that 0 < |L6R2 /L6R1| < 1 can be satisfied.

[Equation 31-1]

0 < L7R1 / L7R2 < 1

In Equation 31-1, L7R1 and L7R2 mean the radii of curvature of the object-side surface and the sensor-side surface of the seventh lens. In Equation 31-1, by setting the radius of curvature of the object-side surface and the sensor-side surface of the seventh lens, light can be refracted to the image sensor through the aspherical lens. Equation 31-1 preferably satisfies 0 < L7R1 / L7R2 < 0.5.

[Equation 32]

0 < Max_CT / Max_CG < 5

In Equation 32, the maximum center thickness (CT_Max) among the lenses and the maximum center spacing (CT_Max) between adjacent lenses can be set. If Equation 32 is satisfied, the optical system can have good optical performance at the focal distance at the set angle of view and can reduce TTL. Preferably, the embodiment may satisfy 1 < Max_CT / Max_CG < 2.

[Equation 33]

1 < ΣCT / ΣCG < 5

In Equation 33, ΣCT is the sum of the central thicknesses of the lenses, and ΣCG is the sum of the central spacing between adjacent lenses. If Equation 33 is satisfied, the optical system can have good optical performance at the focal length at the set angle of view and can reduce TTL. Preferably, the embodiment may satisfy 2 < ΣCT / ΣCG < 3.

[Equation 34]

8 < Σnd < 20

Σnd means the sum of the refractive indices at the d-line of each of the plurality of lenses. If Equation 34 is satisfied, TTL can be controlled in the optical system 1000 where an aspherical lens and a spherical lens are mixed, and improved resolution can be achieved. Additionally, when the number of spherical lenses is greater than the number of aspherical lenses, or when the number of spherical lenses with a relatively thick thickness is greater, the sum of TTL and refractive index can be set. Equation 34 may preferably satisfy 10 < Σnd < 13.

[Equation 35]

10 < ΣAbbe / Σnd < 50

ΣAbbe refers to the sum of Abbe's numbers of each of the plurality of lenses. When Equation 35 is satisfied, the optical system 1000 can have improved aberration characteristics and resolution. By setting Equation 35 to the sum of the Abbes sum and the refractive index of the lenses, optical characteristics can be controlled, and preferably 20 < ΣAbbe / Σnd < 40.

[Equation 36]

Distortion < 2

Distortion refers to the maximum value or absolute value of the maximum distortion from the center (0.0F) of the image sensor to the diagonal end (1.0F) based on the optical characteristics detected by the image sensor 300. When the optical system 1000 satisfies Equation 36, the optical system 1000 can improve distortion characteristics and set conditions for image processing. Preferably, Distortion < 1 can be satisfied.

[Equation 37]

0 < ΣCT / ΣET < 2

ΣCT is the sum of the center thicknesses of the lenses, and ΣET is the end thickness of the effective area of the lenses, that is, the sum of the edge thicknesses. If Equation 37 is satisfied, the optical system can have good optical performance at the focal distance at the set angle of view and can reduce TTL. Equation 37 may preferably satisfy 1 < ΣCT / ΣET < 1.5.

[Equation 38]

0.5 < CA11 / CA_Min < 2.5

CA11 is the effective diameter of the object-side surface of the first lens, and CA_Min represents the minimum effective diameter among the object-side surfaces and sensor-side surfaces of the lenses. If Equation 38 is satisfied, the optical system can control incident light, maintain optical performance, and provide a slimmer module. Equation 38 may preferably satisfy 1 < CA11 / CA_Min < 2.

[Equation 39]

1 < CA_Max / CA_Min < 5

CA_Max represents the maximum effective diameter among the object-side and sensor-side surfaces of the lenses. If Equation 39 is satisfied, the optical system can maintain optical performance and set the size for a slim and compact structure. Equation 39 may preferably satisfy 1 < CA_Max / CA_Min < 2.

[Equation 40]

1 < CA_Max / CA_Aver < 3

CA_Aver represents the average of the effective diameters of the object-side surfaces and sensor-side surfaces of the lenses. If Equation 40 is satisfied, the optical system can maintain optical performance and set a size for a slim and compact structure. Equation 40 may preferably satisfy 1 < CA_Max / CA_Aver < 1.5.

[Equation 41]

0.5 < CA_Min / CA_Aver < 2

If Equation 41 is satisfied, the optical system can maintain optical performance and set the size for a slim and compact structure. Equation 41 may preferably satisfy 0.5 < CA_Min / CA_Aver < 1.

[Equation 42]

1 < CA_Max / (2*ImgH) < 3

Equation 42 can be set to the maximum effective diameter of the lens surfaces (CA_Max) and the diagonal length of the image sensor. If this is satisfied, the optical system can maintain good optical performance and set the size for a slim and compact structure. Equation 42 may preferably satisfy 1 < CA_Max / (2*ImgH) < 2.

[Equation 43]

1 < TD / CA_Max < 4

TD is the optical axis distance from the center of the object side of the first lens to the center of the sensor side of the last lens. If Equation 43 is satisfied, the total optical axis distance and maximum effective diameter of the lenses can be set, and the size for good optical performance can be set. Equation 43 may preferably satisfy 2 < TD / CA_Max < 3.

[Equation 43-1]

TD > SD

The SD is the distance from the position of the aperture to the center of the sensor side of the last lens.

[Equation 44]

1 < F/CA61 < 10

In Equation 44, F represents the effective focal length (EFL) of the optical system, and may be 10 mm or more, for example, in the range of 10 mm to 20 mm. By setting the relationship between the effective focal length and the effective diameter of the object side of the last spherical lens in Equation 44, the influence on optical system reduction, such as TTL, can be adjusted. Equation 44 may preferably satisfy 1 < F / CA61 < 2.

[Equation 45]

0 < F / |L1R1| < 1

By setting the effective focal length of the optical system and the radius of curvature of the object-side surface of the first lens in Equation 45, the influence on incident light and TTL can be adjusted. Equation 45 preferably states that 0.5 < F / |L1R1| < 1 can be satisfied.

[Equation 46]

Max(CT/ET) < 3

Max(CT/ET) represents the maximum ratio of the center thickness and edge thickness of each lens. If Equation 46 is satisfied, the optical system can control the effect on the effective focal length. Equation 46 may preferably satisfy 2 < Max(CT/ET) < 3.

The ratio of the center thickness and edge thickness of the aspherical lens within the lens unit may satisfy the condition of 0.50 < GM(CT/ET) < 1.3. The ratio of the center thickness and edge thickness of the spherical lens within the lens unit may satisfy the condition of 0.50 < GL(CT/ET) < 3.

When the conditions of the aspherical lens are less than the lower limit of the above range, it is difficult to manufacture a glass mold lens. In other words, it is manufactured by injecting high-temperature resin and curing it at low temperature. If the thickness difference is large, the shrinkage may not be uniform as the lens cools at low temperature, resulting in a high surface defect rate. In addition, as the temperature changes from -40 degrees to 105 degrees, the aspherical lens contracts and expands, and in this process, the rate of change in the shape of the lens increases significantly, which can deteriorate the performance of the optical system.

[Equation 47]

0 < EPD / |L1R1| < 1

EPD refers to the size (mm) of the entrance pupil of the optical system 1000, and L1R1 refers to the radius of curvature (mm) of the first surface (S1) of the first lens. When the optical system 1000 according to the embodiment satisfies Equation 47, the optical system 1000 can control incident light. Equation 47 preferably states that 0.3 < EPD / |L1R1| < 0.7 can be satisfied.

[Equation 48]

-10 < F1 / F3 < 0

F1 is the focal length of the first lens, and F3 is the focal length of the third lens. If Equation 48 is satisfied, resolution can be improved by controlling the refractive power of the first and third lenses, and TTL and effective focal length (EFL) can be affected.

[Equation 48-1] ｜F6｜<F4

[Equation 48-2] ｜F6｜<F5

[Equation 48-3] ｜F6｜<｜F7｜

In Equations 48-1 to 48-3, F5 is the focal length of the fifth lens, F4 is the focal length of the fourth lens, F6 is the focal length of the sixth lens, and F7 is the focal length of the seventh lens. Accordingly, the absolute value of the focal length of the sixth lens adjacent to the last aspherical lens may be smaller than the focal length of the fourth and fifth lenses and smaller than the focal length of the seventh lens. Accordingly, the refractive power of the last spherical lens can be controlled to effectively guide light to the aspherical lens.

The aperture ST is disposed on the sensor side of the first lens 101. The focal length of the lens placed on the sensor side rather than the aperture (ST) and closest to the aperture (ST) is greater than 0. In an embodiment of the present invention, F2, the focal length of the second lens 102, must be designed to be greater than 0. In this case, the second lens 102 collects light to prevent the effective diameters of the fourth to seventh lenses, which are lenses disposed closer to the sensor than the second lens 102, from increasing. Additionally, TTL can be prevented from becoming longer, enabling miniaturization of the optical system. The composite focal length of the fourth to seventh lenses 104-107 may have positive refractive power.

The composite focal length of the lens placed closer to the sensor than the aperture (ST), that is, the lens placed closer to the sensor than the aperture, is designed to be greater than 0. In an embodiment of the invention, the composite focal length of the second to seventh lenses is designed to be greater than zero. In this case, the optical system can be miniaturized by reducing the TTL at a horizontal angle of view (FOV_H) of 25 to 35 degrees.

[Equation 49]

Po5 * Po6 < 0

Po5 is the refractive power value of the fifth lens, and Po6 is the refractive power value of the sixth lens. That is, the refractive powers of the fifth and sixth lenses are opposite to each other, so aberrations can be improved and light can be effectively guided to the aspherical lens. If the Po4 * Po5 value is greater than 0, the effect of improving chromatic aberration as a bonded lens is not significant.

[Equation 49-1] Po1(Po5 * Po6) > 0

[Equation 49-2] F56 > 0

[Equation 49-3] F5*F6 < 0

Po1 is the refractive power value of the first lens, F56 is the composite focal length of the fifth and sixth lenses, F5 is the focal length of the fifth lens, and F6 is the focal length of the sixth lens. When Equations 49-1 to 49-3 are satisfied, it is easy to improve the aberration of the optical system with the fifth lens and the sixth lens, which are bonded lenses, and the incident light can be effectively guided to the aspherical lens.

[Equation 50]

15 < v5-v6 < 60

In Equation 50, v5 is the Abbe number of the fifth lens, and v6 is the Abbe number of the sixth lens. If Equation 50 is satisfied, the difference in Abbe number between at least two lenses forming a bonded lens can be maintained above a certain value, and chromatic aberration can be improved. Equation 50 may preferably satisfy 20 < v5-v6 < 40. If the difference in Abbe numbers of the bonded lenses is less than the lower limit of Equation 50, there may be little improvement in the aberration characteristics of the optical system. Accordingly, if the difference in Abbe number between the object-side lens and the sensor-side lens in the bonded lens is greater than 20 and less than 40, aberration characteristics can be improved.

[Equation 50-1]

(v1*n1) < (v2*n2) < (v4*n4)

v1, v2, and v4 are the Abbe numbers of the first, second, and fourth lenses, and n1, n2, and n4 are the refractive indices at the d-line of the first, second, and fourth lenses.

[Equation 51]

0 < |F1 / F| < 20

Equation 51 sets the relationship between the focal length (F1) of the first lens and the effective focal length (F), so that the TTL of the optical system can be set. Equation 51 preferably states that 1 < |F1 / F| < 5 can be satisfied.

[Equation 52]

0 < | F5/F6 | < 2

By setting the relationship between the focal lengths (F5, F6) of the fifth and sixth lenses in Equation 52, the refractive power and optical path of the last spherical lenses can be adjusted and resolution can be improved. Equation 52 preferably has 1 < | F5/F6 | < 1.5 can be satisfied.

[Equation 53]

0 < | F5/F7 | < 1

By setting the relationship between the focal lengths (F5, F7) of the fifth and seventh lenses in Equation 53, the refractive power and optical path of the spherical lens and the last aspherical lens can be adjusted and resolution can be improved. Equation 53 preferably states that 0.2 < | F5/F7 | < 0.6 can be satisfied.

[Equation 54]

0 < | F6/F1 | < 1.2

By setting the relationship between the focal lengths (F1, F6) of the first and sixth lenses in Equation 54, the refractive power and optical path of the first and last spherical lenses can be adjusted, and the influence of TTL is adjusted to improve resolution. I can do it for you. Equation 54 preferably states that 0.1 < | F6/F1 | < 0.6 can be satisfied.

[Equation 55]

0 < | F27/F| < 2

By setting the relationship between the composite focal length (F27) and the effective focal length (F) of the second to seventh lenses in Equation 55, the refractive power of the second to seventh lenses can be controlled to improve resolution, and the optical system can be provided in a slim and compact size. Equation 55 preferably has 0 < | F27/F | < 0.5 can be satisfied.

[Equation 56]

1 < | F47/F6 | < 5

In Equation 56, the relationship between the composite focal length (F47) of the fourth to seventh lenses and the focal length (F6) of the sixth lens is set, and the composite refractive power of the fourth to seventh lenses and the refractive power of the last spherical lens are adjusted. This can improve resolution and provide an optical system in a slim and compact size. Equation (56) preferably states that 2.5 < | F47/F6 | < 4.5 can be satisfied.

[Equation 57]

0 < | F47/F7 | < 3

In Equation 57, the relationship between the composite focal length (F47) of the fourth to seventh lenses and the focal length (F7) of the seventh lens is set, and the composite refractive power of the fourth to seventh lenses and the refractive power of the last aspherical lens are adjusted. This can improve resolution and provide an optical system in a slim and compact size. Equation 57 preferably has 1 < | F47/F7 | < 2 can be satisfied.

[Equation 58]

0 < |F6 / F| < 5

By setting the relationship between the focal length (F6) of the sixth lens and the effective focal length (F) in Equation 58, the refractive power of the last spherical lens and the total focal length can be adjusted to improve resolution, slim the optical system, and It can be provided in a compact size. Equation 58 preferably states that 0 < |F6 / F| < 1 can be satisfied.

[Equation 59]

F_LG1/F_LG2 < 0

In Equation 59, the relationship between the focal length (F_LG1) of the first lens group (LG1) and the focal length of the second lens group (F_LG2) can be set. The focal length of the first lens group may have a negative value, and the focal length of the second lens group may have a positive value. When Equation 59 is satisfied, the optical system 1000 can improve aberration characteristics such as chromatic aberration and distortion aberration. Equation 59 preferably has 2 < | F_LG1/F_LG2 | < 7 can be satisfied.

[Equation 60]

1 < nGL /nGM < 4

In Equation 60, nGL represents the number of spherical lenses, and nGM represents the number of aspherical lenses. In Equation 60, by arranging the number of aspherical lenses to be 1 times more than the number of spherical lenses, the thickness of the optical system can be reduced and more diverse refractive powers can be provided through the aspherical surface. Equation 60 may preferably satisfy 2 < nGL /nGM < 3.

[Equation 61]

1 < nSS / nAS < 4

nSS is the number of lens surfaces having a spherical surface within the lens unit, and nAS is the number of lens surfaces having an aspherical surface within the lens unit. In Equation 61, by arranging the number of aspherical lens surfaces to be 1 times more than the number of spherical lens surfaces, the thickness of the optical system can be reduced and more diverse refractive power can be provided through the aspherical surface. Equation 60 may preferably satisfy 2 < nSS / nAS < 3.

[Equation 62]

CA1 < CA3 < CA4

The effective diameter (CA3) of the third lens may be larger than the effective diameter (CA1) of the first lens and smaller than the effective diameter (CA4) of the fourth lens. Accordingly, the optical path of 8 or less lenses can be set. Additionally, the effective diameter of the fifth lens may satisfy the condition: CA5 < CA3.

[Equation 62-1]

(Max_CAS/Min_CAS) < (Max_CT/Min_CT)

Max_CAS is the maximum among the effective diameters of the object side and sensor side of the lenses, and Min_CAS is the minimum among the effective diameters of the object side and sensor side of the lenses. Max_CT is the maximum central thickness of the lenses, and Min_CT is the minimum central thickness of the lenses. Equation 62-1 sets the difference in effective diameter of the lenses to be smaller than the difference in the center thickness of the lenses, which can improve the assembling of the lenses. Preferably, 1.5 < (Max_CAS/Min_CAS) / (Max_CT/Min_CT) < 4 may be satisfied.

[Equation 63]

0 < ΣGM_CT / ΣGL_CT < 1

ΣGM_CT is the sum of the central thicknesses of the aspherical lens(s), and ΣGL_CT is the sum of the central thicknesses of the spherical lenses. If Equation 62 is satisfied, the entire TTL can be controlled by setting the relationship between the thickness of the aspherical lens and the thickness of the spherical lens compared to TTL. Equation 63 preferably satisfies 0 < ΣGM_CT / ΣGL_CT < 0.5.

[Equation 64]

10mm < TTL < 50mm

Total track length (TTL) refers to the distance (mm) from the center of the first surface S1 of the first lens 101 to the surface of the image sensor 300 on the optical axis OA. In Equation 64, an optical system for a vehicle can be provided by setting the TTL to exceed 10 mm or 20 mm. Equation 64 preferably satisfies the condition of 22mm < TTL < 40mm or TD < TTL.

[Equation 65]

2mm <ImgH

Equation 65 can set the diagonal length (2*ImgH) of the image sensor 300 and provide an optical system having a sensor size for a vehicle. Equation 65 may preferably satisfy 4mm ≤ ImgH.

[Equation 66]

2mm < BFL < 7mm

In Equation 66, the back focal length (BFL) is set to more than 2 mm and less than 7 mm, so that installation space for the optical filter 500 and cover glass 400 can be secured, and the space between the image sensor 300 and the last lens can be secured. Spacing can improve the assembly of components and improve joint reliability. Equation 66 may preferably satisfy 2.5mm ≤ BFL ≤ 3.5mm. If the BFL is less than the range of Equation 68, some of the light traveling to the image sensor may not be transmitted to the image sensor, which may cause resolution deterioration. If the BFL exceeds the range of Equation 68, stray light may enter and the aberration characteristics of the optical system may deteriorate.

[Equation 67]

0 < BFL/CG3 < 1

In Equation 67, the back focal length (BFL) sets the spacing between the lenses, for example, the center spacing (CG3) between the third and fourth lenses, so that the installation space for the optical filter 500 and the cover glass 400 can be secured. And, through the gap between the image sensor 300 and the last lens, the assembly of components can be improved and the coupling reliability can be improved. In Equation 67, the embodiment may satisfy 0.3 < BFL / CG3 < 0.8. The center gap CG3 between the third and fourth lenses may be the largest within the lens unit.

[Equation 68]

1 < CT1 / BFL < 3

In Equation 68, the back focal length (BFL) is set to be smaller than the distance between the lenses, for example, the center thickness of the first lens, so that installation space for the optical filter 500 and the cover glass 400 can be secured, and the image sensor 300 ) and the final lens can improve the assembly of components and improve joint reliability. In addition, the last lens, the seventh lens, can disperse the incident light into the effective area of the image sensor, but if the BFL does not satisfy Equation 68, some of the ejected light may not be transmitted to the effective area of the image sensor. and, as a result, the resolution may be lowered. Preferably, 2 < CT1 / BFL < 3 may be satisfied.

[Equation 69]

3 < F < 40

Equation 69 can set the overall effective focal length (F) to suit the vehicle optical system. Equation 69 can satisfy 10 < F < 30.

[Equation 70]

FOV < 45

In Equation 70, FOV (Field of view) refers to the diagonal angle of view of the optical system 1000, and can provide a vehicle optical system with an angle of less than 45 degrees. The FOV may preferably satisfy 20 ≤ FOV ≤ 40.

[Equation 71]

1 < TTL / CA_Max < 5

CA_Max refers to the largest effective diameter (mm) among the object side and sensor side of the plurality of lenses, and TTL (Total track length) refers to the image sensor ( 300) means the distance (mm) from the optical axis (OA) to the upper surface. Equation 71 sets the relationship between the total optical axis length and the maximum effective diameter of the optical system, thereby providing an improved optical system for vehicles. Equation 71 may preferably satisfy 2 < TTL / CA_Max ≤ 4.

[Equation 72]

2 <TTL/ImgH<15

Equation 72 can set the total optical axis length (TTL) of the optical system and the diagonal length (ImgH) of the optical axis of the image sensor 300. When the optical system 1000 according to the embodiment satisfies Equation 72, the optical system 1000 can have a TTL for application to the automotive image sensor 300, thereby providing improved image quality. Equation 72 may preferably satisfy 4 < TTL / ImgH ≤ 10.

[Equation 73]

0.1 <BFL/ImgH<2

Equation 73 can set the optical axis spacing between the image sensor 300 and the last lens and the diagonal length from the optical axis of the image sensor 300. When the optical system 1000 according to the embodiment satisfies Equation 73, the optical system 1000 can secure a back focal length (BFL) to apply the size of the vehicle image sensor 300, and the last lens and image The spacing between sensors 300 can be set and good optical characteristics can be achieved in the center and periphery of the field of view (FOV). Equation 73 preferably satisfies the condition of 0.3 < BFL / ImgH < 1 and BFL < ImgH.

[Equation 74]

5 <TTL/BFL<20

Equation 74 can set the total optical axis length (TTL) of the optical system and the optical axis distance (BFL) between the image sensor 300 and the last lens. When the optical system 1000 according to the embodiment satisfies Equation 55, the optical system 1000 can secure BFL. Equation 74 may preferably satisfy 8 < TTL / BFL < 16.

[Equation 75]

1 < TTL/F < 3

Equation 75 can set the total focal length (F) and total optical axis length (TTL) of the optical system 1000. Accordingly, an optical system for a driver assistance system can be provided. Equation 75 may preferably satisfy 1.5 ≤ TTL / F ≤ 2.8. When the optical system 1000 according to the embodiment satisfies Equation 75, the optical system 1000 can have an appropriate focal distance in the set TTL range, maintains the appropriate focal distance even when the temperature changes from low to high, and does not form an image. Provides an optical system that can be used. If it is less than the lower limit of Equation 75, it is necessary to increase the refractive power of the lenses, making correction of spherical aberration or distortion aberration difficult, and if it is more than the upper limit of Equation 75, the effective diameter or TTL of the lenses becomes longer, making it difficult to capture images. A problem may arise where the lens system becomes larger.

[Equation 76]

1 < F/BFL < 10

Equation 76 can set the overall effective focal length (F) of the optical system 1000 and the optical axis spacing (BFL) between the image sensor 300 and the last lens. When the optical system 1000 according to the embodiment satisfies Equation 76, the optical system 1000 can have a set angle of view and an appropriate focal distance, and can provide an optical system for a vehicle. Additionally, the optical system 1000 can minimize the gap between the last lens and the image sensor 300 and thus have good optical characteristics in the peripheral area of the field of view (FOV). Equation 76 may preferably satisfy 3 < F / BFL < 8.

[Equation 77]

1 < F/ImgH < 5

Equation 77 can set the total effective focal length (F) of the optical system 1000 and the diagonal length (ImgH) at the optical axis of the image sensor 300. This optical system 1000 may have improved aberration characteristics in the size of the vehicle image sensor 300. Equation 77 may preferably satisfy 2 < F / ImgH < 4.1.

[Equation 78]

1 < F/EPD < 5

Equation 78 can set the total effective focal length (F) and entrance pupil size of the optical system 1000. Accordingly, the overall brightness of the optical system can be controlled. Equation 78 can preferably set 1 < F / EPD < 3.

[Equation 79]

0 < BFL/TD < 0.3

Equation 79 can establish the relationship between the optical axis distance (TD) and the back focal length (BFL) of the lenses of the optical system 1000. Accordingly, the overall size can be controlled while maintaining the resolution of the optical system. Equation 79 may preferably satisfy 0 < BFL/TD < 0.2. If the condition value of BFL/TD is more than 0.2, BFL is designed to be large compared to TD, so the size of the entire optical system becomes large, making it difficult to miniaturize the optical system, and the distance between the seventh lens and the image sensor becomes longer. , As a result, the amount of unnecessary light may increase through between the seventh lens and the image sensor, and there is a problem of lowering resolution, such as lowering aberration characteristics.

[Equation 80]

0 < EPD/ImgH/FOV < 0.2

Equation 80 can establish the relationship between the entrance pupil size (EPD), the length of half the diagonal length of the image sensor (ImgH), and the angle of view in the diagonal direction. Accordingly, the overall size and brightness of the optical system can be controlled. Equation 80 may preferably satisfy 0 < EPD/ImgH/FOV < 0.1.

[Equation 81]

5 < FOV / F# < 40

Equation 81 can establish the relationship between the angle of view in the diagonal direction of the optical system and the F number. Equation 81 preferably satisfies 10 < FOV / F # < 30. Here, F# can be set to 1.8 or less to provide a bright image.

[Equation 82]

1 < ΣGL_CT / F# < 20

Equation 82 can establish the relationship between the sum of the central thicknesses of the glass lenses of the optical system (ΣGL_CT) and the F number (F#). Preferably, in Equation 82, the embodiment may satisfy 1 < ΣGL_CT / F# < 5, and the second embodiment may satisfy 5 < ΣGL_CT / F# < 15.

[Equation 83]

1 < ΣGM_CT / F# < 5

Equation 83 can establish the relationship between the sum of the central thicknesses of the aspherical lenses of the optical system (ΣGM_CT) and the F number (F#). Equation 83 may preferably satisfy 1 < ΣGM_CT / F# < 3.

[Equation 84]

1 < ΣGL_nd / F# < 10

Equation 84 can establish the relationship between the sum of refractive indices (ΣGL_nd) and the F number (F#) of the spherical lenses of the optical system. Equation 84 may preferably satisfy 3 < ΣGL_nd / F# < 10.

[Equation 85]

1 < ΣGM_nd / F# < 10

Equation 84 can establish the relationship between the refractive index sum (ΣGM_nd) and the F number (F#) of the aspherical lenses of the optical system. Equation 84 may preferably satisfy 1 < ΣGM_nd / F# < 5.

[Equation 86]

|Max_Sag62| < |Max_Sag51|

Max_Sag62 is the maximum distance in the optical axis direction from the straight line perpendicular to the optical axis on the sensor side of the sixth lens to the sensor side of the sixth lens, and Max_Sag51 is the maximum distance in the optical axis direction from the straight line perpendicular to the optical axis on the object side of the fifth lens. This is the maximum distance in the optical axis direction to the object side of the fifth lens. If Equation 86 is satisfied, light can be guided from the last spherical lens to the last aspherical lens by the radius of curvature of the sensor side of the sixth lens, and the effective diameters of the fifth and sixth lenses can be adjusted.

[Equation 87]

|Max_Sag72| < |Max_Sag62|

Max_Sag72 is the maximum distance in the optical axis direction from the straight line perpendicular to the optical axis from the sensor side of the seventh lens to the sensor side of the seventh lens. If Equation 87 is satisfied, light can be guided from the last spherical lens to the last aspherical lens by the radius of curvature of the sensor side of the sixth lens, and the effective diameters of the sixth and seventh lenses can be adjusted.

[Equation 87-1]

|Max_Sag41| < |Max_Sag52|

|Max_Sag52| < |Max_Sag51|

|Max_Sag72| < |Max_Sag71|

Equation 87-1 can satisfy at least one of the above equations.

Max_Sag41 is the maximum distance in the optical axis direction from the straight line perpendicular to the optical axis from the object-side surface of the fourth lens to the object-side surface of the fourth lens. Max_Sag52 is the maximum distance in the optical axis direction from the straight line perpendicular to the optical axis from the sensor side of the fifth lens to the sensor side of the fifth lens. Max_Sag71 is the maximum distance in the optical axis direction from the straight line perpendicular to the optical axis from the object-side surface of the seventh lens to the object-side surface of the seventh lens.

[Equation 88]

In Equation 93, Z is Sag and can mean the distance in the optical axis direction from any position on the aspherical surface to the vertex of the aspherical surface. The Y may refer to the distance from any position on the aspherical surface to the optical axis in a direction perpendicular to the optical axis. The c may refer to the curvature of the lens, and K may refer to the Conic constant. Additionally, A, B, C, D, E, and F may mean aspheric constants.

The optical system 1000 according to the embodiment may satisfy at least one or two of Equations 1 to 44. At least one or two or more of Equations 1 to 44 may satisfy at least one or two or more of Equations 45 to 87. In this case, the optical system 1000 may have improved optical characteristics. In detail, when the optical system 1000 satisfies at least one of Equations 1 to 44 and/or at least one of Equations 45 to 87, the optical system 1000 has improved resolution and can improve aberration and distortion characteristics. You can. In addition, the optical system 1000 can secure a back focal length (BFL) for applying the automotive image sensor 300, compensate for the decrease in optical characteristics due to temperature changes, and the last lens and image sensor 300. ) can be minimized, allowing for good optical performance in the center and periphery of the field of view (FOV).

Table 2 shows the items of the above-described equations in the optical system 1000 of the embodiment, including the total track length (mm), back focal length (BFL), and effective focal length (F) of the optical system 1000 ( mm), ImgH (mm), effective diameter (CA) (mm), thickness (mm), TTL (mm), TD (mm), which is the optical axis distance from the first surface (S1) to the fourteenth surface (S14), Focal distance of each of the first to seventh lenses (F1, F2, F3, F4, F5, F6, F7) (mm), sum of refractive index, sum of Abbe number, sum of thickness (mm), sum of spacing between adjacent lenses , diagonal angle of view (FOV) (Degree), edge thickness (ET), focal length of the first and second lens groups, F number, etc.

item Example item Example F 15.138 ET1 9.066 F1 -31.303 ET2 1.424 F2 30.367 ET3 2.303 F3 65.717 ET4 1.477 F4 35.095 ET5 1.535 F5 13.344 ET6 3.631 F6 -11.681 ET7 2.362 F7 -29.278 CT56 6.101 F_LG1 -31.303 ET56 5.166 F_LG2 11.041 F-number 1.597 F13 35.793 FOV (diagonal) 34.263 F47 42.399 E.P.D. 9.481 F56 173.247 BFL 3.200 Σnd 11.676 TD 33.458 ΣAbbe 349.671 ImgH 4.626 ΣCT 24.118 SD 24.979 ΣCG 9.339 TTL 36.658 ΣET 21.798 Sensor size 3840*2160

Table 3 shows the result values for Equations 1 to 44 described above in the optical system 1000 of the embodiment. Referring to Table 3, it can be seen that the optical system 1000 satisfies at least one, two, or three of Equations 1 to 44. In detail, it can be seen that the optical system 1000 according to the embodiment satisfies all of Equations 1 to 44 above. Accordingly, the optical system 1000 can have good optical performance in the center and periphery of the field of view (FOV) and can have excellent optical characteristics.

math equation Example One 1 < CT1 / CT2 < 5 3.377 2 (CT7*CA7) < (CT1*CA1) Satisfaction 3 Po1 < 0 -0.032 4 1.7 < n3 < 2.2 1.694 5 20 <FOV_H<40 30.00 6 L1R1 < 0 -18.523 7 0.8 < BFL / Max_Sag72 to Sensor < 3 1.045 8 3 < CT1 / CT7 < 7 4.864 9 0 < CT3 / CT7 < 3 1.617 10 1 < CT56 / CT7 < 5 3.392 11 0 < |L2R1 / L4R2| < 1 0.326 12 0 < (CT45 - ET45) < 2 1.181 13 0 < CA11 / CA31 < 2 0.908 14 0 < CA72 / CA42 < 2 0.681 15 0 < CA12 / CA21 < 2 0.965 16 0 < CA31 / CA42 < 2 0.976 17 0 < CA51 / CA62 < 2 1.339 18 0 < CA62 / CA71 < 2 1.076 19 0.2 < GL_CA_Aver/GM_CA_Aver < 2 1.034 20 0 < GL_nd_Aver/GM_nd_Aver < 1.60 0.948 21 CA6, CA7 < CA5 Satisfaction 22 CG2 < CG6 <CG3 Satisfaction 23 0 < CT7 / CG6 < 1 0.593 24 LD34<LD12 Satisfaction 25 CG57 < CG14 Satisfaction 26 1 < CT6/CT7 < 3 1.195 27 10 < L7R1/CT7 < 40 27.581 28 0 < |L5R2 / L7R1| < 10 0.527 29 L1R1*L1R2 < 0 1722.987 30 0 < |L5R1 /L6R2| < 2 0.934 31 0 < |L6R2/L6R1| < 2 0.504 32 0 < Max_CT / Max_CG < 5 0.673 33 1 < ΣCT / ΣCG < 5 2.582 34 8 < ΣIndex <20 11.676 35 10 < ΣAbbe / Σnd <50 29.947 36 Distortion < 2 Satisfaction 37 0 < ΣCT / ΣET < 2 1.106 38 0.5 < CA11 / CA_Min < 2.5 1.349 39 1 < CA_Max / CA_Min < 5 1.551 40 1 < CA_Max / CA_Aver < 3 1.162 41 0.5 < CA_Min / CA_Aver < 2 0.749 42 1 < CA_Max / (2*ImgH) < 3 1.478 43 1 < TD / CA_Max < 4 2.446 44 1 < F/CA61 < 10 1.292

Table 4 shows the result values for Equations 45 to 87 described above in the optical system 1000 of the embodiment. Referring to Table 4, it can be seen that the optical system 1000 satisfies at least one, two, or three of Equations 45 to 87. In detail, it can be seen that the optical system 1000 according to the embodiment satisfies all of Equations 1 to 87 above. Accordingly, the optical system 1000 can have good optical performance in the center and periphery of the field of view (FOV) and can have excellent optical characteristics.

math equation Example 45 0 < F / |L1R1| < 1 0.817 46 Max (CT/ET) < 3 2.650 47 0 <EPD/|L1R1| < 1 0.512 48 -10 < F1 / F3 < 0 -0.476 49 Po5 * Po6 < 0 Satisfaction 50 15 < v4-v5 < 60 18.212 51 0 < |F1 / F| < 20 2.068 52 0 < | F5 /F6 | < 2 1.142 53 0 < | F5 /F7 | < 1 0.456 54 0 < | F6/F1 | < 1.2 0.373 55 0 < | F27 / F1| < 2 0.353 56 1 < | F47/F6 | < 5 3.630 57 0< | F47/F7 | < 3 1.448 58 0 < |F6 / F| < 5 0.772 59 F_LG1/F_LG2 < 0 Satisfaction 60 1 < nGL /nGM < 4 2.500 61 1 < nSS / nAS <4 2.500 62 CA5 < CA3 < CA1 Satisfaction 63 0 < ΣGM_CT / ΣGL_CT < 1 0.113 64 10 < TTL < 50 36.658 65 2 <ImgH 4.626 66 2<BFL<7 3.200 67 0.1< BFL / CG3 < 1 0.575 68 1 < CT1 / BFL < 3 2.587 69 3 < F < 40 15.138 70 FOV < 45 34.263 71 1 < TTL / CA_Max < 5 2.680 72 2 <TTL/ImgH<15 7.924 73 0.1 <BFL/ImgH<2 0.692 74 5 <TTL/BFL<20 11.455 75 1 < TTL/F < 3 2.422 76 1 < F/BFL < 10 4.731 77 1 < F/ImgH < 5 3.272 78 1 < F/EPD < 5 1.597 79 0 < BFL/TD < 0.3 0.0956 80 0 < EPD/Imgh/FOV < 0.2 0.0142 81 5 < FOV / F# < 40 21.459 82 1 < ΣGL_CT / F# < 20 12.316 83 1 < ΣGM_CT / F# < 5 1.395 84 1 < ΣGL_nd / F# < 10 5.142 85 1 < ΣGM_nd / F# < 10 2.171 86 |Max_Sag62 | < |Max_Sag51| Satisfaction 87 |Max_Sag72| < |Max_Sag62| Satisfaction

Figure 14 is an example of a top view of a vehicle to which a camera module or optical system is applied according to an embodiment of the invention.

Referring to FIG. 14, the vehicle camera system according to an embodiment of the invention includes an image generator 11, a first information generator 12, and a second information generator 21, 22, 23, 24, 25, 26. ) and a control unit 14. The image generator 11 may include at least one camera module 31 disposed in the host vehicle, and may capture a front image of the host vehicle and/or the driver to generate a front image of the host vehicle or an image of the interior of the vehicle. You can. The image generator 11 may use the camera module 31 to capture not only the front of the vehicle but also the surroundings of the vehicle in one or more directions to generate an image surrounding the vehicle. Here, the front image and peripheral image may be digital images and may include color images, black-and-white images, and infrared images. Additionally, the front image and surrounding image may include still images and moving images. The image generator 11 provides the driver image, front image, and surrounding image to the control unit 14. Next, the first information generator 12 may include at least one radar or/and a camera disposed in the host vehicle, and generates first detection information by detecting the front of the host vehicle. Specifically, the first information generator 12 is disposed in the host vehicle and generates first detection information by detecting the location and speed of vehicles located in front of the host vehicle, the presence and location of pedestrians, etc.

The first detection information generated by the first information generator 12 can be used to control the distance between the own vehicle and the vehicle in front to be kept constant, and when the driver wants to change the driving lane of the own vehicle or reverse parking. The stability of vehicle operation can be improved in certain preset cases, such as when driving. The first information generation unit 12 provides first detection information to the control unit 14. The second information generators 21, 22, 23, 24, 25, and 26 are based on the front image generated by the image generator 11 and the first sensed information generated by the first information generator 12, Second sensing information is generated by detecting each side of the vehicle. Specifically, the second information generators 21, 22, 23, 24, 25, and 26 may include at least one radar or/and camera disposed on the host vehicle, and may include positions of vehicles located on the sides of the host vehicle. and speed can be detected or video taken. Here, the second information generation units 21, 22, 23, 24, 25, and 26 may be disposed at both front corners, side mirrors, and the rear center and rear corners of the vehicle, respectively.

At least one information generator of these vehicle camera systems may include an optical system described in the embodiment(s) disclosed above and a camera module having the same, and may include information acquired through the front, rear, each side, or corner area of the vehicle. It can be provided to the user or processed to protect vehicles and objects from automatic driving or surrounding safety.

The optical system of the camera module according to an embodiment of the invention can be mounted in multiple instances in a vehicle to improve safety regulations, strengthen autonomous driving functions, and increase convenience using ADAS (Advanced Driving Assistance System). Additionally, the optical system of the camera module is used in vehicles as a control component for lane keeping assistance systems (LKAS), lane departure warning systems (LDWS), and driver monitoring systems (DMS). These automotive camera modules can provide stable optical performance despite changes in ambient temperature and provide price-competitive modules to ensure the reliability of automotive components.

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. illustrated in each embodiment can be combined or modified and implemented in other embodiments by a person with ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

In addition, although the above description has been made focusing on the examples, this is only an example and does not limit the present invention, and those skilled in the art will understand the above examples without departing from the essential characteristics of the present embodiment. You will be able to see that various modifications and applications are possible. For example, each component specifically shown in the examples can be modified and implemented. And these variations and differences in application should be construed as being included in the scope of the present invention as defined in the appended claims.

1st lens: 101 2nd lens: 102
Third lens: 103 Fourth lens: 104
5th lens: 105 6th lens: 106
7th lens: 107 Lens section: 100
Image sensor: 300 Cover glass: 400
Filter: 500 Optics: 1000

Claims (24)

It includes first to seventh lenses aligned along the optical axis from the object side toward the sensor side,
The refractive power of the first lens is negative,
The composite refractive power of the second to seventh lenses is positive,
The refractive power of the seventh lens is negative,
The first lens is a spherical lens with a maximum central thickness,
An optical system in which the central thickness of the first lens is greater than the optical axis distance from the center of the object-side surface of the fifth lens to the center of the sensor-side surface of the sixth lens. According to paragraph 1,
The center spacing between the ith lens and the i+1 lens is CGi,
The central thickness of the ith lens is CTi,
An optical system in which the value of CTi/CGi is maximum when i is 1. According to clause 2,
The value of CTi/CGi is minimum when i is 3. According to claim 1,
The effective diameter of the first lens is CA1,
The effective diameter of the second lens is CA2,
The effective diameter of the third lens is CA3,
The effective diameter of the fourth lens is CA4,
Equation: CA1 < CA2 < CA3 < CA4
An optical system that satisfies . According to clause 4,
The length from the center of the image sensor to the diagonal end is ImgH,
The effective diameter of the fifth lens is CA5,
The effective diameter of the sixth lens is CA6,
The effective diameter of the seventh lens is CA7,
Equation: CA4 > CA5 > CA6 > (2*Imgh) > CA7
An optical system that satisfies . According to any one of claims 1 to 5,
An optical system in which the sensor-side surface of the fifth lens and the object-side surface of the sixth lens are adhered to each other. According to any one of claims 2 to 5,
An optical system comprising an aperture disposed around the circumference between the first lens and the second lens. According to any one of claims 2 to 5,
The object side and sensor side of the third lens are aspherical at the optical axis,
An optical system in which the object-side surface and the sensor-side surface of the seventh lens are aspherical on the optical axis. According to any one of claims 2 to 5,
The first to seventh lenses are made of glass,
An optical system in which the number of lenses whose object-side and sensor-side surfaces are spherical on the optical axis is more than twice the number of lenses whose object-side and sensor-side surfaces are aspherical. According to any one of claims 1 to 3,
The central thickness of the first lens is CT1,
The optical axis distance from the center of the object side of the first lens to the surface of the image sensor is TTL,
Equation: 0.18 ≤CT1/TTL≤0.3
An optical system that satisfies . According to any one of claims 1 to 3,
The maximum central thickness of the first to seventh lenses is Max_CT,
The maximum center spacing between the first to seventh lenses is Max_CG,
Equation: 1 < Max_CT / Max_CG < 2
An optical system that satisfies . First to seventh lenses aligned along the optical axis from the object side toward the sensor side; And
It includes an aperture disposed between any two of the first lens and the third lens,
The refractive power of the first lens is negative,
The seventh lens has an aspherical surface on the object side and a sensor side on the optical axis,
The composite refractive power of the fourth to seventh lenses is positive,
An optical system wherein the effective diameter difference between the object-side surface and the sensor-side surface of the sixth lens is greater than the effective diameter difference between the object-side surface and the sensor-side surface of each of the first to fourth lenses. According to claim 12,
The first lens has a meniscus shape convex from the optical axis toward the sensor,
An optical system in which the central thickness of the first lens is greater than the sum of the central thicknesses of two adjacent lenses among the second to seventh lenses. According to claim 12,
An optical system in which the lens having the maximum effective diameter among the first to seventh lenses is disposed between a lens whose object-side surface and sensor-side surface are aspherical on the optical axis and a bonded lens in which two adjacent lenses are joined. The method according to any one of claims 12 to 14,
The third lens is an aspherical lens at the optical axis,
An optical system in which the fifth and sixth lenses are bonded lenses. The method according to any one of claims 12 to 14,
The first to seventh lenses are made of glass,
The aperture is disposed around the perimeter between the first lens and the second lens,
An optical system wherein one of the first to third lenses is an aspherical lens on the optical axis. According to claim 16,
The number of lenses whose object and sensor sides are spherical on the optical axis is more than twice the number of lenses whose object and sensor sides are aspherical.
An optical system in which the number of lenses with an effective diameter smaller than the diagonal length of the image sensor is two or less. The method according to any one of claims 12 to 14,
The fifth and sixth lenses are lenses bonded with opposite refractive powers,
An optical system in which the composite focal length of the fifth and sixth lenses has a positive value. image sensor;
first to seventh lenses aligned along the optical axis from the object side toward the sensor side;
An aperture disposed between spherical lenses among the first to seventh lenses: and
Includes an optical filter between the seventh lens and the image sensor,
The first lens has a meniscus shape convex from the optical axis toward the sensor,
The first and seventh lenses have negative refractive power,
The composite refractive power of the second to seventh lenses is positive,
Any one of the first to fourth lenses is an aspherical lens,
The aspherical lens is a camera module disposed between lenses having a meniscus shape with both sides convex at the optical axis. According to clause 19,
The third lens is an aspherical lens and has a meniscus shape convex from the optical axis toward the object,
The second and fourth lenses are camera modules having convex shapes on both sides of the optical axis. According to clause 19,
Among the fifth to seventh lenses, it includes a bonded lens in which two lenses having opposite refractive powers are bonded together,
The bonded lens is a camera module including a lens whose sides are convex on the optical axis and a lens whose sides are concave on the optical axis. According to claim 20,
The bonded lens is a lens in which the fifth and sixth lenses disposed between the fourth lens and the seventh lens are bonded,
A camera module in which the seventh lens is an aspherical lens. The method of claim 21 or 22,
The central thickness of the first lens is thicker than the central thickness of the bonded lens,
The center spacing between the third and fourth lenses is the maximum among the center spacings between the first to seventh lenses, and is in the range of 84% to 95% of the center thickness of the bonded lens. According to any one of claims 19 to 22,
The number of lenses whose object-side and sensor-side surfaces are spherical is more than twice the number of lenses whose object-side and sensor-side surfaces are aspherical.
The distance from the center of the object side of the first lens to the surface of the image sensor is TTL,
1/2 of the diagonal length of the image sensor is ImgH,
The maximum effective diameter of the lenses on the object side and the sensor side is CA_Max,
Equation: 2 < TTL / ImgH < 15
1 < CA_Max / (2*ImgH) < 3
A camera module that satisfies the requirements.

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