Optical system and camera device including the same

Abstract

An optical system according to an embodiment of the present invention includes, in order from an object side to an image side, a first lens having a negative diopter, a second lens having a negative diopter, a third lens having a positive diopter, a fourth lens having a negative diopter, a fifth lens having a negative diopter, a sixth lens having a positive diopter, and an image sensor having a negative diopter. The fourth lens has positive diopter, the fifth lens has negative diopter, the sixth lens has positive diopter, an aperture is arranged between the third lens and the fourth lens, the first lens to the third lens have negative composite diopter, and the fourth lens to the sixth lens have positive composite diopter.

Description

Technical Field

[0001] Embodiments of the present invention relate to an optical system and a camera device including the optical system. Background Art

[0002] An advanced driver assistance system (ADAS) is an advanced driver assistance system that assists a driver in driving, senses a situation in front of a vehicle, determines a situation based on the sensing result, and controls vehicle behavior based on the determined situation. For example, an ADAS sensor device detects a vehicle in front and identifies a lane. After that, once a target lane, a target speed, and a target in front are determined, an electronic stability control system (ESC), an engine management system (EMS), an electric power steering system (MDPS), etc. of the vehicle are controlled. Representatively, ADAS can be implemented as an automatic parking system, a low-speed urban driving assistance system, a blind spot warning system, etc.

[0003] The ADAS sensor device includes a GPS sensor, a laser scanner, a front radar, a lidar, etc., and the most representative ADAS sensor device is a camera for photographing the front, rear, and sides of a vehicle.

[0004] The camera can be disposed outside or inside the vehicle to detect the surrounding environment of the vehicle. In addition, the camera can be disposed inside the vehicle to detect the situation of a driver and passengers. For example, the camera can photograph the driver from a position near the driver and detect the health condition of the driver, whether the driver is sleepy, whether the driver is drunk, etc. In addition, the camera can photograph the passengers from a position near the passengers, detect whether the passengers are sleeping, the health condition of the passengers, etc., and provide information about the passengers to the driver.

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

[0006] Technical Problem

[0007] The technical problem to be solved by the present invention is to provide an optical system having improved optical characteristics and a camera device including the optical system.

[0008] Another technical problem to be solved by the present invention is to provide an optical system having excellent optical performance in a low temperature to high temperature environment and a camera device including the optical system.

[0009] Another technical problem to be solved by the present invention is to provide an optical system and a camera device including the optical system that can prevent or minimize changes in optical characteristics within various temperature ranges.

[0010] Technical solution

[0011] An optical system according to an embodiment of the present invention includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and an image sensor sequentially arranged from an object side to an image side. Among them, the first lens has a negative diopter, the second lens has a negative diopter, the third lens has a positive diopter, the fourth lens has a positive diopter, the fifth lens has a negative diopter, the sixth lens has a positive diopter. An aperture is provided between the third lens and the fourth lens. The first lens to the third lens have a negative combined diopter, and the fourth lens to the sixth lens have a positive combined diopter.

[0012] The image-side surface of the third lens may be concave, and the object-side surface of the fourth lens may be concave.

[0013] The ratio (R6 / R7) of the radius of curvature R6 of the image-side surface of the third lens to the radius of curvature R7 of the object-side surface of the fourth lens may be -3 or less.

[0014] The effective diameter of the object-side surface of the first lens may be 8 mm or more and 9.5 mm or less.

[0015] The effective diameter of the object-side surface of the first lens may be greater than the diagonal length of the image sensor, and the effective diameter of the image-side surface of the first lens may be less than the diagonal length of the image sensor.

[0016] The ratio of the effective diameter of the object-side surface of the first lens to the diagonal length of the image sensor may be 1.05 or more and 1.3 or less, and the ratio of the effective diameter of the image-side surface of the first lens to the diagonal length of the image sensor may be 0.4 to 0.7.

[0017] At least one of the object-side surface and the image-side surface of the second lens may include a critical point with an inclination angle of 0, and the inclination angle of the image-side surface of the first lens in a region more than four times the distance from the optical axis to the critical point may be 30 degrees or more.

[0018] The ratio of the edge thickness of the first lens to the center thickness of the first lens may be 1.2 or more and 3 or less.

[0019] Among the first distance between the first lens and the second lens, the second distance between the second lens and the third lens, the third distance between the third lens and the fourth lens, the fourth distance between the fourth lens and the fifth lens, and the fifth distance between the fifth lens and the sixth lens, the second distance can be the smallest.

[0020] The fourth distance is the next smallest distance after the second distance.

[0021] The ratio of the back focal length (BFL) to the total track length (TTL) (BFL / TTL) can be from 0.35 to 0.5.

[0022] The ratio (R1 / R2) of the radius of curvature R1 of the object-side surface of the first lens to the radius of curvature R2 of the image-side surface of the first lens can be from 3 to 4.5.

[0023] Advantageous Effects

[0024] The optical system according to an embodiment of the present invention and a camera device including the optical system can have improved optical characteristics. In the optical system according to an embodiment of the present invention, the plurality of lenses can have set thicknesses, refractive powers, and distances between adjacent lenses. Therefore, the optical system according to an embodiment of the present invention and a camera device including the optical system can have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. within a set field of view, and can have excellent optical performance at the periphery of the field of view.

[0025] In addition, the optical system according to an embodiment of the present invention and a camera device including the optical system can have excellent optical performance in a temperature range from low temperature to high temperature (-40°C to 105°C). Specifically, the plurality of lenses included in the optical system can have set materials, refractive powers, and refractive indices. Therefore, when the refractive index of each lens changes due to temperature change and thus the focal length of each lens changes, mutual compensation can be performed by plastic lenses and glass lenses. That is, the optical system can effectively perform the distribution of refractive power in a temperature range from low temperature to high temperature, and prevent or minimize the change of optical characteristics in a temperature range from low temperature to high temperature. Therefore, the optical system according to an embodiment and a camera device including the optical system can maintain improved optical characteristics in various temperature ranges.

[0026] In addition, the optical system according to an embodiment and a camera device including the optical system can satisfy a set field of view and achieve excellent optical characteristics through a combination of plastic lenses and glass lenses. Therefore, the optical system can provide a thinner in-vehicle camera module. Therefore, the optical system and a camera device including the optical system can be set for various applications, devices, etc., and can have excellent optical characteristics even when exposed to a harsh temperature environment (for example, outside a vehicle or inside a vehicle in summer high temperature). Description of the Drawings

[0027] Figure 1 and Figure 2 shows an optical system according to an embodiment of the present invention.

[0028] Figure 3 shows characteristics of an optical system according to an embodiment of the present invention.

[0029] Figure 4 shows the aspherical coefficients of an aspherical lens in an optical system according to an embodiment of the present invention.

[0030] Figure 5 is design data showing the distance between lens surfaces according to the distance along the Y direction from the optical axis in an optical system according to an embodiment of the present invention.

[0031] Figure 6 is design data showing the sag values of lens surfaces according to the distance along the Y direction from the optical axis in the first lens to the sixth lens of an optical system according to an embodiment of the present invention.

[0032] Figure 7 is design data showing the tilt angles of lens surfaces according to the distance along the Y direction from the optical axis in an optical system according to an embodiment of the present invention.

[0033] Figure 8 is a graph showing RI data according to the position of an image sensor in an optical system according to an embodiment of the present invention.

[0034] Figures 9 to 11 shows Figure 1 a graph of data of the diffraction modulation transfer function (MTF) of visible light of an optical system at room temperature, low temperature, and high temperature.

[0035] Figures 12 to 14 shows Figure 1 a graph of data of the diffraction modulation transfer function (MTF) of IR light of an optical system at room temperature, low temperature, and high temperature.

[0036] Figure 15 is an example of a plan view of a vehicle to which an optical system according to an embodiment of the present invention or a camera device including the optical system is applied. Detailed Description of the Invention

[0037] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0038] However, the technical concept of the present invention is not limited to the described embodiments, but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more components in the embodiments can be selectively combined or used interchangeably.

[0039] In addition, unless specifically defined and described explicitly, the terms (including technical terms and scientific terms) used in the embodiments of the present invention can be interpreted as having the meanings that are generally understood by those of ordinary skill in the technical field to which the present invention pertains, and the commonly used terms (such as the terms defined in a dictionary) can be interpreted in consideration of the context meaning of the related technology.

[0040] In addition, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention.

[0041] In this specification, unless otherwise specifically stated in the wording, the singular can also include the plural, and when described as "at least one (or more than one) of A, B, and C", it can include more than one of all combinations in which A, B, and C can be combined.

[0042] In addition, when describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. can be used.

[0043] These terms are only intended to distinguish one component from another, and the nature, order, sequence, etc. of the components are not limited by these terms.

[0044] In addition, when a component is described as "connected", "coupled", or "joined" to another component, it can include not only the case where the component is directly connected, coupled, or joined to the other component, but also the case where the component is "connected", "coupled", or "joined" through yet another component located between the component and the other component.

[0045] In addition, when a component is described as being formed or disposed "above (on) or below (under)" another component, above (on) or below (under) includes not only the case where the two components are in direct contact with each other, but also the case where one or more other components are formed or disposed between the two components. In addition, when expressed as "above (on) or below (under)", it can include not only the meaning of the upward direction based on one component, but also the meaning of the downward direction based on that one component.

[0046] Figure 1 and Figure 2An optical system according to an embodiment of the present invention is shown. Here, the Z direction is the optical axis direction, the X direction is the direction perpendicular to the optical axis direction and parallel to one side of the image sensor, and the Y direction is the direction perpendicular to the optical axis direction and the X direction. Hereinafter, an example in which the ratio of the X-axis length to the Y-axis length of the image sensor is 4:3 is described, but it is not limited thereto. Figure 3 shows the characteristics of the optical system according to an embodiment of the present invention, Figure 4 shows the aspherical coefficient of the aspherical lens in the optical system according to an embodiment of the present invention.

[0047] Referring to Figure 1 and Figure 2 , the optical system 100 according to an embodiment of the present invention may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a filter 170, and an image sensor 180 that are sequentially arranged from the object side to the image side.

[0048] Although not shown, a right-angle prism may be further provided at the front end of the first lens 110.

[0049] At least one of the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, and the sixth lens 160 may include an effective region and a non-effective region. The effective region may be a region through which light incident on the lens passes, that is, a region where the incident light is refracted and optical characteristics are achieved. In the present specification, the effective diameter may refer to the diameter of the effective region where the effective light is incident on each surface of each lens. In the present specification, the numerical value of the effective diameter may have a certain error range. For example, for the numerical value of the effective diameter given in the present specification, a range of ±0.4 mm may be regarded as the effective region, and for the numerical value of the effective diameter given in the present specification, a range of ±0.4 mm may be interpreted as the effective diameter. The non-effective region may be provided around the effective region and may be a region where light does not enter, that is, a region irrelevant to the optical characteristics. The non-effective region may be a region fixed to a lens barrel or the like that houses the lens. In the present specification, the diameter of the lens may be the entire diameter of the lens including the flange portion of the lens in addition to the effective region of the lens. Although the flange of the lens is not shown in the present specification, the flange may be a portion formed to protrude from the side surface of the lens in a direction perpendicular to the optical axis so that the lens is combined with the lens barrel. The effective light may not be incident on the flange. A spacer may be additionally provided between the flanges of different lenses so that the lens is combined with the lens barrel.

[0050] According to an embodiment of the present invention, the filter 170 and the image sensor 180 may be sequentially disposed at the rear end of the sixth lens 160. At this time, the filter 170 may be a filter that transmits visible light and blocks infrared (IR) light. Therefore, the filter 170 may block near-infrared light in the light incident on the optical system 100, for example, light having a wavelength of 700 nm to 1100 nm. Accordingly, radiant heat emitted from external light can be prevented from being transferred to the image sensor 180. Alternatively, the filter 170 may be a filter that transmits IR light and blocks visible light.

[0051] The filter 170 may be disposed between the sixth lens 160 and the image sensor 180.

[0052] The image sensor 180 may be coupled to a printed circuit board. The image sensor 180 may detect light and convert the detected light into an electrical signal. The image sensor 180 may detect light that sequentially passes through the first lens to the sixth lens. The image sensor 180 may include a device capable of detecting incident light, such as a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

[0053] The cover glass 190 may be disposed between the filter 170 and the image sensor 180, may protect the upper portion of the image sensor 180, and may prevent a reduction in the reliability of the image sensor 180. The cover glass 190 may be omitted. The cover glass 190 may be a protective glass.

[0054] According to an embodiment of the present invention, the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, and the sixth lens 160 are sequentially disposed along the optical axis.

[0055] In this specification, the "object-side surface" may refer to the surface of the lens that faces the object side with respect to the optical axis OA, and the "image-side surface" may refer to the surface of the lens that faces the imaging surface (i.e., the image sensor) with respect to the optical axis. One surface of the lens that bulges may refer to a shape that bulges in the optical axis or paraxial region, and one surface of the lens that is recessed may refer to a shape that is recessed in the optical axis or paraxial region. The paraxial region is a very narrow region near the optical axis, and is a region where the distance of light to the optical axis OA is almost 0. Hereinafter, the meaning of the optical axis may include the center of each lens or a very narrow region near the optical axis. The radius of curvature, the center thickness, and the optical axis spacing between the lenses listed in the lens data sheet may refer to values on the optical axis (unit: mm). The vertical direction may refer to a direction perpendicular to the optical axis, and the end of the lens or the lens surface may refer to the end of the effective region of the lens through which the incident light passes.

[0056] According to an embodiment of the present invention, the optical system 100 and the camera device including the optical system 100 can be installed inside or outside a vehicle to monitor a driver or sense an external object or a lane. The material of the lens can be selected from glass or plastic, and the linear expansion coefficient of the glass material can be less than that of the plastic material. Therefore, a glass lens can be used to suppress the change in the focal imaging position due to temperature change. However, since the glass lens is more expensive than the plastic lens, there is a problem that it is difficult to meet the low-cost requirement. Therefore, a configuration in which a glass lens and a plastic lens are combined and used in the optical system 100 is required. When the optical system 100 includes a plastic lens, weight reduction and cost reduction can be achieved, and various aberrations such as spherical aberration and chromatic aberration can be excellently corrected due to the plastic lens. In addition, since the plastic lens can provide an aspherical lens, the distortion of the outer periphery can be minimized.

[0057] The optical system 100 can include n lenses. The nth lens can be the last lens adjacent to the image sensor 180, and the (n - 1)th lens can be the lens closest to the last lens. n is an integer greater than or equal to 6, for example, 6 to 8. The ratio of the number of plastic lenses to glass lenses among the n lenses can be in the range of 2:3 to 2:6 or in the range of 3:4 to 3:5.

[0058] In an embodiment of the present invention, the optical system 100 can include a plurality of lens groups LG1 and LG2, and each of the plurality of lens groups LG1 and LG2 can include at least one lens. For example, the optical system 100 can 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 180.

[0059] The number of lenses in each of the first lens group LG1 and the second lens group LG2 can be the same or different. For example, the first lens group LG1 can include three lenses, and the second lens group LG2 can include three lenses. For example, the first lens group LG1 can include a first lens 110, a second lens 120, and a third lens 130, and the second lens group LG2 can include a fourth lens 140, a fifth lens 150, and a sixth lens 160.

[0060] The first lens group LG1 can include at least one glass lens and at least one plastic lens. In the first lens group LG1, the lens closest to the object side (i.e., the first lens 110) can be a glass lens. The amount of change in expansion and contraction of the glass lens due to external temperature change is small, and its surface is not easily scratched, thereby preventing surface damage.

[0061] The second lens group LG2 may include at least one glass lens and at least one plastic lens. In the second lens group LG2, the lens closest to the object side (i.e., the fourth lens 140) may be a glass lens.

[0062] The rate of change of shrinkage and expansion of the glass material due to temperature change is less than that of the plastic material due to temperature change. Therefore, the lens closest to the outside in the first lens group LG1 and the lens closest to the outside in the second lens group LG2 may be made of glass material.

[0063] According to an embodiment of the present invention, the lenses made of plastic material may be continuously arranged in the first lens group LG1, and the lenses made of plastic material may be continuously arranged in the second lens group LG2. In the optical system 100, the lens made of glass material in the second lens group LG2 may be arranged between the lens made of plastic material in the first lens group LG1 and the lens made of plastic material in the second lens group LG2. The plastic lens can be realized to be lightweight, low-cost, easy to design an aspherical surface, and easy to eliminate chromatic aberration.

[0064] According to an embodiment of the present invention, the first lens 110 of the first lens group LG1 may be a lens made of glass material, the second lens 120 and the third lens 130 may be lenses made of plastic material, the fourth lens 140 of the second lens group LG2 may be a lens made of glass material, and the fifth lens 150 and the sixth lens 160 may be lenses made of plastic material. Each lens includes an object-side surface and an image-side surface. The object-side surface and the image-side surface of the lens made of glass material may both be spherical surfaces, and the object-side surface and the image-side surface of the lens made of plastic material may both be aspherical surfaces. According to an embodiment of the present invention, since the number of aspherical surfaces in the optical system 100 is greater than the number of spherical surfaces, various aberrations can be corrected.

[0065] Referring to Figures 1 to 4 , according to an embodiment of the present invention, among the first lens to the sixth lens included in the optical system 100, the first lens 110 arranged closest to the object side may have the maximum refractive index. For example, the refractive index of the first lens 110 may be 1.7 or more. Therefore, the dispersion of the light incident on the first lens 110 can be increased, the central thickness can be made thinner than the edge thickness, the curvature radii of the second lens and subsequent lenses can be easily changed, and the central thickness can be increased.

[0066] Similarly, among the fourth lens to the sixth lens included in the second lens group LG2, the fourth lens 140 arranged closest to the object side may have the maximum refractive index. For example, the refractive index of the fourth lens 140 may be 1.7 or more. Therefore, the dispersion of the light incident on the fourth lens 140 can be increased.

[0067] The first lens group LG1 may have a negative refractive power, and the second lens group LG2 may have a positive refractive power. Among the lenses of the first lens group LG1, the lens closest to the object side may have a negative refractive power, and among the lenses of the second lens group LG2, the lens closest to the sensor side may have a positive refractive power. When the focal length is expressed as an absolute value, the focal length of the first lens group LG1 may be greater than the focal length of the second lens group LG2. For example, it may be 1.1 to 2 times, preferably 1.1 to 1.5 times, and more preferably 1.1 to 1.3 times the focal length of the second lens group LG2. When expressed as an absolute value, the effective focal length (EFL) of the optical system 100 may be less than the focal length of the first lens group LG1. The effective focal length (EFL) of the optical system 100 may be less than the absolute value of the focal length of the second lens group LG2.

[0068] The number of lenses with positive refractive power in the optical system 100 may be the same as the number of lenses with negative refractive power.

[0069] The first lens 110 may be a glass lens, may have a negative refractive power, may include an object-side surface 112 and an image-side surface 114, and the object-side surface 112 of the first lens 110 may be convex toward the object side, and the image-side surface 114 may be concave toward the image side. Here, the convex surface of the lens may refer to the lens surface having a convex shape in the region corresponding to the optical axis, and the concave surface of the lens may refer to the lens surface having a concave shape in the region corresponding to the optical axis. Here, the region corresponding to the optical axis may refer to the optical axis or the paraxial region. In addition, the surface of the lens convex toward the object side may mean that the surface is concave toward the image side, and the surface of the lens convex toward the image side may mean that the surface is concave toward the object side.

[0070] The second lens 120 may have a negative refractive power, include an object-side surface 122 and an image-side surface 124, and the object-side surface 122 of the second lens 120 may be concave toward the object side, and the image-side surface 124 may be concave toward the image side.

[0071] The third lens 130 may have a positive refractive power, include an object-side surface 132 and an image-side surface 134, and the object-side surface 132 of the third lens 130 may be convex toward the object side, and the image-side surface 134 may be concave toward the image side.

[0072] The fourth lens 140 may have a positive refractive power, include an object-side surface 142 and an image-side surface 144, and the object-side surface 142 of the fourth lens 140 may be concave toward the object side, and the image-side surface 144 may be convex toward the image side.

[0073] The fifth lens 150 may have a negative refractive power, including an object-side surface 152 and an image-side surface 154, and the object-side surface 152 of the fifth lens 150 may be recessed toward the object side, and the image-side surface 154 may be recessed toward the image side.

[0074] The sixth lens 160 may have a positive refractive power, including an object-side surface 162 and an image-side surface 164, and the object-side surface 162 of the sixth lens 160 may be convex toward the object side, and the image-side surface 164 may be convex toward the image side.

[0075] According to an embodiment of the present invention, in the first lens group LG1, the first lens 110 and the second lens 120 may have negative refractive powers, and the third lens 130 may have a positive refractive power. The Abbe number of the third lens 130 in the first lens group LG1 may be less than the Abbe numbers of the first lens 110 and the second lens 120. The difference between the Abbe number of the third lens 130 and the Abbe number of the first lens 110 or the second lens 120 may be 20 or more, preferably 25 or more. Therefore, the chromatic aberration of the first lens group LG1 can be reduced by the third lens 130.

[0076] According to an embodiment of the present invention, in the second lens group LG2, the fourth lens 140 and the sixth lens 160 may have positive refractive powers, and the fifth lens 150 between the fourth lens 140 and the sixth lens 160 may have a negative refractive power. In addition, in the second lens group LG2, the Abbe number of the fifth lens 150 may be less than the Abbe numbers of the fourth lens 140 and the sixth lens 160. The difference between the Abbe number of the fifth lens 150 and the Abbe number of the fourth lens 140 or the sixth lens 160 may be 20 or more, preferably 25 or more. Therefore, the fifth lens 150 can eliminate the chromatic aberration of the second lens group LG2.

[0077] According to an embodiment of the present invention, the Abbe number of the fourth lens 140 disposed between the third lens 130 and the fifth lens 150 for correcting chromatic aberration may be greater than the Abbe numbers of the third lens 130 and the fifth lens 150. For example, the Abbe number of the fourth lens 140 may be 20 or more greater than the Abbe numbers of the third lens 130 and the fifth lens 150, preferably 25 or more greater. For example, the Abbe number of the fourth lens 140 may be about 49. In addition, the difference between the maximum Abbe number and the minimum Abbe number in the optical system 100 may be 20 or more and 60 or less, preferably 25 or more and 50 or less, more preferably 30 or more and 40 or less. Therefore, an optical system can be obtained that can obtain high-quality and high-pixel images, is applicable to visible light and IR light, and is applicable to temperature changes from -40°C to 85°C.

[0078] The optical system 100 according to an embodiment of the present invention may include an aperture stop. The aperture may control the amount of light incident on the optical system 100. According to an embodiment of the present invention, the aperture stop may be disposed between the first lens group LG1 and the second lens group LG2. That is, the aperture stop may be disposed between the image side surface 134 of the third lens 130 and the object side surface 142 of the fourth lens 140.

[0079] For this purpose, the first lens group LG1 and the second lens group LG2 may have a predetermined spacing on the optical axis OA. The optical axis spacing between the first lens group LG1 and the second lens group LG2 on the optical axis OA may be the optical axis spacing between the image side surface of the lens closest to the sensor side in the first lens group LG1 and the object side surface of the lens closest to the object side in the second lens group LG2. Here, among the lens surfaces of the first lens group LG1 and the second lens group LG2, two surfaces facing each other, for example, the image side surface of the lens located on the object side may be concave, and the object side surface of the lens located on the sensor side may be concave. That is, the image side surface 134 of the third lens 130 may be concave, and the object side surface 142 of the fourth lens 140 may be concave. Therefore, the first lens group LG1 may diffuse the light incident from the object side, and the second lens group LG2 may refract the light diffused by the first lens group LG1 into the area of the image sensor 180.

[0080] As described above, the first lens group LG1 may have a negative refractive power, and the second lens group LG2 may have a positive refractive power. For example, the combined refractive power of the first lens group LG1 is -0.23, and the combined refractive power of the second lens group LG2 is 0.28. Therefore, the first lens group LG1 may diffuse the light incident from the object side, and the second lens group LG2 may refract the light diffused by the first lens group LG1 into the area of the image sensor 180.

[0081] According to an embodiment of the present invention, the ratio (R6 / R7) of the radius of curvature R6 of the image side surface 132 of the third lens 130 to the radius of curvature R7 of the object side surface 141 of the fourth lens 140 may be -3 or less, preferably -5 or less, and more preferably -8 or less. The sensitivity between the image side surface 132 of the third lens 130 and the object side surface 141 of the fourth lens 140 where the aperture is disposed therebetween can be improved, and the divergence angle can be reduced. In particular, the image side surface 134 of the third lens 130 may have a concave but almost flat shape, which can reduce the divergence angle of the light from the image side surface 134 of the third lens 130. In addition, the object side surface 142 of the fourth lens 140 having a positive refractive power may have a concave shape so that the incident angle remains small, thereby reducing aberration.

[0082] According to an embodiment of the present invention, among the first lens to the sixth lens included in the optical system 100, the first lens 110 disposed closest to the object side may have the largest effective diameter, and the effective diameter may tend to decrease from the object-side surface 112 of the first lens 110 to the image-side surface 134 of the third lens 130, and then increase from the object-side surface of the fourth lens 140 to the image-side surface of the sixth lens 160. According to an embodiment of the present invention, the first lens 110 may have the largest effective diameter, and the effective diameters of the third lens to the fifth lens between the second lens 120 and the sixth lens 160 may be smaller than the effective diameter of the second lens 120 and the effective diameter of the sixth lens 160. Therefore, since the light incident on the optical system 100 tends to approach the optical axis and then move away from the optical axis, a stable optical path can be formed, and the light can reach the outer periphery of the image sensor 180 uniformly.

[0083] In addition, when the object-side surface 112 of the first lens 110 has the largest effective diameter in the optical system 100, the amount of light incident on the optical system 100 can be increased to improve the brightness of the optical system 100, the resolution of the optical system 100 and the deterioration of the optical characteristics due to temperature changes can be compensated, the chromatic aberration control characteristics can be improved, and the vignetting characteristics of the optical system 100 can be improved.

[0084] For example, the effective diameter ED of the first lens 110 L1S1 may be 8 mm or more, preferably 8 mm or more and 9.5 mm or less, more preferably 8.5 mm or more and 9 mm or less.

[0085] According to an embodiment of the present invention, the effective diameter of the object-side surface 112 of the first lens 110 may be greater than the diagonal length of the image sensor 180. For example, the diagonal length 2*H of the image sensor 180 included in the optical system 100 according to an embodiment of the present invention imageD may be 7.28 mm, the length of the image sensor 180 in the horizontal direction (i.e., the X-axis direction) may be 5.76 mm, and the length of the image sensor 180 in the vertical direction (i.e., the Y-axis direction) may be 4.46 mm. For example, the effective diameter ED of the object-side surface 112 of the first lens 110 L1S1 and the diagonal length 2*H of the image sensor 180 imageD The ratio may be 1.05 or more and 1.3 or less, preferably 1.1 or more and 1.2 or less, more preferably 1.12 or more and 1.18 or less. When the effective diameter ED of the first lens 110 L1S1 and the diagonal length 2*H of the image sensor 180 imageDWhen the above numerical range is satisfied, the amount of light incident on the object-side surface 112 of the first lens 110 can be maximized within the range where the first lens 110 can be manufactured, and a field of view of more than 150 degrees can be achieved. When it is less than the lower limit of the above numerical range, it is difficult for a sufficient amount of light to reach the outer periphery of the image sensor at a field of view of more than 150 degrees. When it exceeds the upper limit, there are problems such as difficulty in manufacturing the first lens and an increase in the size of the optical system 100.

[0086] According to an embodiment of the present invention, the effective diameter ED of the object-side surface 112 of the first lens 110 L1S1 can be larger than the diagonal length of the image sensor 180, and the effective diameter ED of the image-side surface 114 of the first lens 110 L1S1 can be smaller than the diagonal length of the image sensor 180. For example, the ratio of the effective diameter ED of the image-side surface 114 of the first lens 110 L1S2 to the diagonal length 2*H of the image sensor 180 imageD can be 0.4 or more and 0.7 or less, preferably 0.45 or more and 0.65 or less, more preferably 0.5 or more and 0.6 or less. Therefore, the field of view of the first lens 110 can be expanded. That is to say, an optical system can be realized in which the field of view is more than 150 degrees and the ratio of the amount of light incident on the outer periphery of the image sensor to the amount of light incident on the central portion of the image sensor (i.e., relative illuminance (RI)) is 50% or more, and the field of view is more than 170 degrees and the relative illuminance is 30% or more. Here, the central portion of the image sensor refers to the region close to the 0 field of view of the image sensor, and the outer periphery of the image sensor refers to the region close to the 1 field of view of the image sensor.

[0087] At this time, the ratio of the effective diameter ED of the object-side surface 112 of the first lens 110 L1S1 to the effective diameter ED of the image-side surface 114 of the first lens 110 L1S1 can be 1.5 or more and 3 or less, preferably 1.7 or more and 2.6 or less, more preferably 1.9 or more and 2.3 or less. At this time, the ratio (R1 / R2) of the radius of curvature R1 of the object-side surface 112 of the first lens 110 to the radius of curvature R2 of the image-side surface 114 of the first lens 110 can be 3 to 4.5, preferably 3.25 to 4.25, more preferably 3.5 to 4. Therefore, the field of view of the first lens 110 can be expanded. That is to say, an optical system with a field of view of more than 150 degrees and an RI of 50% or more and a field of view of more than 170 degrees and an RI of 30% or more can be realized.

[0088] According to an embodiment of the present invention, the effective diameter ED of the object-side surface 112 of the first lens 110 L1S1It can be 0.2 times to 1 times of the TTL of the optical system, preferably 0.4 times to 0.8 times, and more preferably 0.5 times to 0.7 times. When the effective diameter ED of the first lens 110 L1S1 and the TTL satisfy the above numerical range, the overall size of the optical system 100 can be balanced and it is easy to manufacture.

[0089] The center thickness CT of the object side surface 112 of the first lens 110 represents the distance from the object side surface 112 to the image side surface 114 of the first lens 110. For example, the center thickness of the object side surface 112 of the first lens 110 can represent the distance between the center of curvature of the object side surface 112 and the center of curvature of the image side surface 114 in the first lens 110. The center distance CG of the image side surface 114 of the first lens 110 represents the distance from the image side surface 114 of the first lens 110 to the object side surface 122 of the second lens 120. Specifically, the center distance of the image side surface 114 of the first lens 110 represents the center distance between the center of curvature of the image side surface 114 of the first lens 110 and the center of curvature of the object side surface 122 of the second lens 120, that is, the air gap.

[0090] According to an embodiment of the present invention, the ratio of the edge thickness ET1 of the first lens 110 to the center thickness CT1 of the first lens 110 can be 1.2 or more and 3 or less, preferably 1.3 or more and 2.5 or less, and more preferably 1.5 or more and 2 or less. Therefore, an ultra-wide-angle optical system with a field of view of 150 degrees or more and an RI of 50% or more, and a field of view of 170 degrees or more and an RI of 30% or more can be realized. In addition, as described above, the first lens 110 is a glass lens. When the center thickness CT1 and the edge thickness ET1 in the first lens 110 as a glass lens satisfy the above conditions, even when it is disposed on the outermost side of the optical system 100 and exposed to an environment of frequent jitter and vibration, the risk of breakage can be minimized and it is easy to be combined with the flange.

[0091] According to an embodiment of the present invention, among the first center distance CG1 between the first lens 110 and the second lens 120, the second center distance CG2 between the second lens 120 and the third lens 130, the third center distance CG3 between the third lens 130 and the fourth lens 140, the fourth center distance CG4 between the fourth lens 140 and the fifth lens 150, and the fifth center distance CG5 between the fifth lens 150 and the sixth lens 160, the second center distance CG2 can be the shortest. In this way, since the air gap on the object side surface 132 side of the third lens 130 that functions in eliminating chromatic aberration is minimized, the tolerance sensitivity and imaging performance of the optical system 100 can be improved.

[0092] According to an embodiment of the present invention, among the first center distance CG1 between the first lens 110 and the second lens 120, the second center distance CG2 between the second lens 120 and the third lens 130, the third center distance CG3 between the third lens 130 and the fourth lens 140, the fourth center distance CG4 between the fourth lens 140 and the fifth lens 150, and the fifth center distance CG5 between the fifth lens 150 and the sixth lens 160, the fourth center distance CG4 can be the next shortest distance after the second center distance CG2. In this way, since the air gap on the object side surface 152 side of the fifth lens 150 that functions in eliminating chromatic aberration is minimized, the tolerance sensitivity and imaging performance of the optical system 100 can be improved.

[0093] According to an embodiment of the present invention, among the first center distance CG1 between the first lens 110 and the second lens 120, the second center distance CG2 between the second lens 120 and the third lens 130, the third center distance CG3 between the third lens 130 and the fourth lens 140, the fourth center distance CG4 between the fourth lens 140 and the fifth lens 150, and the fifth center distance CG5 between the fifth lens 150 and the sixth lens 160, the first center distance CG1 can be the largest. At this time, the ratio (R3 / R2) of the radius of curvature R3 of the object side surface 122 of the second lens 120 to the radius of curvature R2 of the image side surface 114 of the first lens 110 can be -5 to -0.5, preferably -3 to -0.5, more preferably -2 to -1. In addition, the ratio (R3 / R2 / CG1) of the radius of curvature R3 of the object side surface 122 of the second lens 120 to the radius of curvature R2 of the image side surface 114 of the first lens 110 with respect to the center distance CG1 between the first lens 110 and the second lens 120 can be -5 to -0.1, preferably -3 to -0.2, more preferably -2 to -0.5. Therefore, the influence of the ghost image of the first lens 110 and the second lens 120 on the entire optical system 100 can be minimized, and the light output from the image side surface 114 of the first lens 110 can be effectively incident on the object side surface 122 of the second lens 120 without loss.

[0094] According to an embodiment of the present invention, among the first lens to the sixth lens, the third lens 130 can have the largest center thickness. In this way, when the center thickness of the third lens 130, which is disposed in front of the aperture stop and has a positive refractive power, is the largest, the amount of light incident on the aperture stop can be maximized. As described above, the third lens 130 is a plastic lens. When the third lens 130, which has the largest center thickness among the first lens to the sixth lens, is a plastic lens, the weight of the entire optical system 100 can be reduced.

[0095] According to an embodiment of the present invention, the central thickness CT3 of the third lens 130 may be more than 0.25 times and less than 0.45 times, preferably more than 0.28 times and less than 0.4 times, and more preferably more than 0.3 times and less than 0.36 times the sum CT_16 of the central thicknesses of the first lens 110 to the sixth lens 160. The third lens may function in condensing light and correcting chromatic aberration, and may maximize the amount of light incident on the aperture stop.

[0096] According to an embodiment of the present invention, the central thickness CT3 of the third lens 130 may be more than twice, preferably more than three times, and more preferably more than 3.5 times the central thickness CT2 of the second lens 120. Therefore, since the optical axes of the second lens 120 and the third lens 130 are easily aligned, the assemblability can be improved. In addition, when the central thickness of the third lens 130 with positive refractive power is more than twice the central thickness of the second lens 120 with negative refractive power, chromatic aberration can be effectively eliminated from the third lens 130.

[0097] According to an embodiment of the present invention, among the first lens to the sixth lens, the sixth lens 160 may have the next largest central thickness after the third lens 130. Thus, when the central thickness of the sixth lens 160, which is disposed closest to the image sensor 180 and has positive refractive power, is large, the amount of light incident on the image sensor 180 can be maximized. As described above, the sixth lens 160 is a plastic lens. When the sixth lens 160, which has the second largest central thickness among the first lens to the sixth lens, is a plastic lens, the weight of the entire optical system 100 can be reduced.

[0098] According to an embodiment of the present invention, the ratio (f5 / f6) of the effective focal length f5 of the fifth lens 150 to the effective focal length f6 of the sixth lens 160 may be -1.02 or less and -0.95 or less, preferably -1.015 or more and -0.97 or less, and more preferably -1.015 or more and -0.98 or less. Therefore, the tolerance sensitivity and the overall optical imaging performance of the optical system 100 can be improved to increase productivity.

[0099] According to an embodiment of the present invention, the ratio (CG5 / (CT5+CT6)) of the center distance CG5 between the fifth lens 150 and the sixth lens 160 to the sum of the center distance CT5 of the fifth lens 150 and the center distance CT6 of the sixth lens 160 may be 0.02 or more and 0.07 or less, preferably 0.04 or more and 0.065 or less, and more preferably 0.05 or more and 0.06 or less. Therefore, the tolerance sensitivity and the overall optical imaging performance of the optical system 100 can be improved to increase productivity.

[0100] According to an embodiment of the present invention, the ratio (F456 / F) of the effective focal lengths F456 of the fourth lens to the sixth lens to the effective focal length F of the optical system 100 may be 1.5 or more and 1.665 or less, preferably 1.55 or more and 1.665 or less, and more preferably 1.6 or more and 1.665 or less. Therefore, the tolerance sensitivity and the overall optical imaging performance of the optical system 100 can be improved to increase the productivity.

[0101] According to an embodiment of the present invention, the distance TTL from the object-side surface 112 of the first lens 110 to the image sensor 180 is 10 mm to 18 mm, preferably 12 mm to 16 mm, and more preferably 13 mm to 15 mm. In addition, the distance BFL from the image-side surface 164 of the sixth lens 160 to the image sensor 180 is 4 mm or more and 8 mm or less, preferably 5 mm or more and 7 mm or less, and more preferably 5.5 mm or more and 6.5 mm or less. In addition, the diagonal length (2*H imageD ) of the image sensor 180 is 7.28 mm. Considering the assembly performance, from the perspective of those skilled in the art, the BFL needs to be implemented as 4 mm or more. For example, in the case of a camera device having an autofocus function, for the assembly of the optical system and the image sensor, the BFL needs to be implemented as 4 mm or more.

[0102] According to an embodiment of the present invention, the total top length (TTL, Total top length) in the optical system 100 may be 1.3 times or more and 2.5 times or less of the diagonal length (2*H imageD ) of the image sensor 180, preferably 1.5 times or more and 2.3 times or less, and more preferably 1.8 times or more and 2.1 times or less. In the optical system 100, the effective focal length (EFL) may be 2 mm or more, preferably 2.1 mm or more, and the field of view (FOV) may be 150 degrees or more, preferably 170 degrees or more, so that it can be set as a standard optical system in an in-vehicle camera module. For example, the optical system according to an embodiment and a camera device including the optical system can be applied to a camera for an advanced driver assistance system (ADAS) provided inside or outside a vehicle.

[0103] Here, the length of the image sensor 180 is the maximum length in the diagonal direction orthogonal to the optical axis OA, which may be less than the effective diameter of the lens closest to the object in the first lens group LG1 and may be greater than the effective diameter of the lens closest to the sensor in the second lens group LG2. Here, the number of lenses having an effective diameter greater than the length of the image sensor 180 may be 1 to 3, and the number of lenses having an effective diameter less than the length of the image sensor 180 may be 3 to 5.

[0104] According to an embodiment of the present invention, the ratio of the TTL of the optical system 100 to the effective focal length F may be 6 or more and 7 or less, preferably 6.2 or more and 6.8 or less, and more preferably 6.4 or more and 6.6 or less. Accordingly, a compact and lightweight optical system 100 can be obtained.

[0105] According to an embodiment of the present invention, the ratio of the BFL of the optical system 100 to the TTL may be 0.35 or more and 0.5 or less, preferably 0.37 or more and 0.48 or less, and more preferably 0.4 or more and 0.45 or less. Accordingly, since not only a compact and lightweight optical system 100 can be obtained, but also the distance BFL between the image-side surface 164 of the sixth lens 160 and the image sensor 180 can be ensured, the assemblability and productivity of the optical system 100 can be improved, and the RI of the image sensor 180 can be improved.

[0106] Figure 5 is design data showing the distance between lens surfaces according to the distance along the Y direction from the optical axis in the optical system according to an embodiment of the present invention, Figure 6 is design data showing the sagittal height values of the lens surfaces according to the distance along the Y direction from the optical axis in the first lens to the sixth lens of the optical system according to an embodiment of the present invention, Figure 7 is design data showing the tilt angle of the lens surface according to the distance along the Y direction from the optical axis in the optical system according to an embodiment of the present invention. In Figures 5 to 7Among them, L1, L2, L3, L4, L5 and L6 respectively represent the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150 and the sixth lens 160. S1 and S2 respectively represent the object-side surface and the image-side surface. L1S1, L1S2, L2Sl, L2S2, L3S1, L3S2, L4S1, L4S2, L5S1, L5S2, L6S1 and L6S2 respectively represent the object-side surface 112 and the image-side surface 114 of the first lens 110, the object-side surface 122 and the image-side surface 124 of the second lens 120, the object-side surface 132 and the image-side surface 134 of the third lens 130, the object-side surface 142 and the image-side surface 144 of the fourth lens 140, the object-side surface 152 and the image-side surface 154 of the fifth lens 150, and the object-side surface 162 and the image-side surface 164 of the sixth lens 160. The air gap (air) between L1 and L2 represents the distance between the first lens 110 and the second lens 120. The air gap between L2 and L3 represents the distance between the second lens 120 and the third lens 130. The air gap between L3 and L4 represents the distance between the third lens 130 and the fourth lens 140. The air gap between L4 and L5 represents the distance between the fourth lens 140 and the fifth lens 150. The air gap between L5 and L6 represents the distance between the fifth lens 150 and the sixth lens 160.

[0107] Referring to Figures 1 to 7 , among the first center distance CG1 between the first lens 110 and the second lens 120, the second center distance CG2 between the second lens 120 and the third lens 130, the third center distance CG3 between the third lens 130 and the fourth lens 140, the fourth center distance CG4 between the fourth lens 140 and the fifth lens 150, and the fifth center distance CG5 between the fifth lens 150 and the sixth lens 160, the second center distance CG2 can be the smallest. At this time, with respect to the second center distance CG2 between the second lens 120 and the third lens 130, the maximum distance D23max between the second lens 120 and the third lens 130 can be 1.01 times or more and 4 times or less of the second center distance CG2. Therefore, since the air gap on the object-side surface 132 side of the third lens 130 that functions in chromatic aberration correction is minimized, and the light output from the image-side surface 124 of the second lens 120 is incident on the object-side surface 132 of the third lens 130 almost perpendicularly, the light is refracted uniformly within the third lens 130, and the chromatic aberration correction performance of the third lens 130 can be maximized.

[0108] According to an embodiment of the present invention, among the first center distance CG1 between the first lens 110 and the second lens 120, the second center distance CG2 between the second lens 120 and the third lens 130, the third center distance CG3 between the third lens 130 and the fourth lens 140, the fourth center distance CG4 between the fourth lens 140 and the fifth lens 150, and the fifth center distance CG5 between the fifth lens 150 and the sixth lens 160, the fourth center distance CG4 may be the next smallest distance after the second center distance CG2. At this time, with respect to the fourth center distance CG4 between the fourth lens 140 and the fifth lens 150, the maximum distance D45max between the fourth lens 140 and the fifth lens 150 may be 1.01 times or more and 4 times or less of the fourth center distance CG4. In this way, since the air gap on the object side surface 152 side of the fifth lens 150, which plays a role in eliminating chromatic aberration, is minimized, and the light output from the image side surface 144 of the fourth lens 140 is incident on the object side surface 152 of the fifth lens 150 almost perpendicularly, the light is refracted uniformly within the fifth lens 150, and the chromatic aberration correction performance of the fifth lens 150 can be maximized.

[0109] In addition, the sag value refers to the distance on the optical axis between an arbitrary point on the lens surface and a point on the optical axis. In this specification, Sagn1 may refer to the distance on the optical axis between an arbitrary point on the object side surface of the nth lens and a point on the optical axis, and Sagn2 may refer to the distance on the optical axis between an arbitrary point on the image side surface of the nth lens and a point on the optical axis. For example, Sag11 may refer to the distance on the optical axis between an arbitrary point on the object side surface 112 of the first lens 110 and a point on the optical axis, and Sag12 may refer to the distance on the optical axis between an arbitrary point on the image side surface 114 of the first lens 110 and a point on the optical axis. The sag value may refer to the absolute value.

[0110] According to an embodiment of the present invention, at least one of the maximum sag value of the object side surface 112 of the first lens 110 or the maximum sag value of the image side surface 114 may be greater than the maximum sag value of the remaining lens surfaces in the optical system 100. For example, the maximum sag value of the object side surface 112 and the maximum sag value of the image side surface 114 of the first lens 110 may each be greater than the maximum sag value of the remaining lens surfaces in the optical system 100. For example, the maximum sag value of the object side surface 112 and the maximum sag value of the image side surface 114 of the first lens 110 may be 1 mm or more. As described above, since the first lens 110 is a glass lens, even when it has a maximum sag value of 1 mm or more, its optical performance can be maintained. When the maximum sag value of the object side surface 112 and the maximum sag value of the image side surface 114 of the first lens 110 are 1 mm or more, an ultra-wide-angle optical system of 150 degrees or more can be achieved.

[0111] In addition, according to an embodiment of the present invention, at least one surface of at least one of the first lens to the sixth lens forming the optical system 100 includes a critical point. The critical point may refer to a point where the trend of the sag value changes. The point where the trend of the sag value changes may be a point where the sag value increases and then decreases, or a point where the sag value decreases and then increases. The critical point may refer to a point where the tilt angle becomes 0. The tilt angle may be defined as the angle formed by the normal of the tangent of the lens surface and the optical axis.

[0112] According to an embodiment of the present invention, at least one of the six surfaces of the first lens 110, the second lens 120, and the third lens 130 includes a critical point. Light is refracted more effectively near the critical point. That is, compared with the light passing through the lens surface that does not include the critical point, the light passing through the lens surface that includes the critical point can be refracted more effectively. Therefore, when at least one of the six surfaces of the first lens 110, the second lens 120, and the third lens 130 includes a critical point, the light incident through the effective diameter of the object side surface 112 of the first lens 110 can be refracted within as wide a range as possible between the first lens and the third lens, the light can reach the peripheral pixels of the image sensor 180 uniformly through the aperture Stop, and the performance of the optical system 100 can be improved.

[0113] For example, according to an embodiment of the present invention, the image side surface 124 of the second lens 120 may include a critical point. More specifically, according to an embodiment of the present invention, the critical point of the image side surface 124 of the second lens 120 may be a point where the perpendicular distance from the optical axis is 0.1 mm or more and 0.6 mm or less, preferably 0.2 mm or more and 0.5 mm or less, and more preferably 0.3 mm or more and 0.4 mm or less. For example, when the optical axis is the starting point and the end of the image side surface 124 of the second lens 120 is the ending point, the critical point of the image side surface 124 of the second lens 120 may be set at a position of 6% or more and 38% or less, preferably 12% or more and 32% or less, and more preferably 19% or more and 25% or less. Here, the end of the lens surface may refer to the end of the effective area of the lens surface, and the position of the critical point may be a position set based on the direction perpendicular to the optical axis.

[0114] In this way, when the critical point exists on one or more surfaces (for example, three surfaces) of the total six surfaces of the first lens to the third lens, the light can be evenly distributed in the first lens to the third lens, output through the image side surface 134 of the third lens 130, and incident on the object side surface 142 of the fourth lens 140 through the aperture Stop.

[0115] As described above, among the first lens to the sixth lens included in the optical system 100, the object-side surface 112 of the first lens 110 may have the largest effective diameter, and the ratio of the effective diameter of the object-side surface 112 of the first lens 110 to the effective diameter of the image-side surface 114 of the first lens 110 may be 1.5 to 2.5, preferably 1.8 to 2.3, more preferably 2 to 2.3, and the ratio (R1 / R2) of the radius of curvature R1 of the object-side surface 112 of the first lens 110 to the radius of curvature R2 of the image-side surface 114 of the first lens 110 may be 3 to 4.5, preferably 3.25 to 4.25, more preferably 3.5 to 4. At this time, in a region more than four times the distance from the optical axis to the critical point of the image-side surface 124 of the second lens 120, the tilt angle of the image-side surface 114 of the first lens 110 may be 30 degrees or more. Therefore, the field of view of the first lens 110 can be enlarged. That is, an optical system having a field of view of 150 degrees or more and an RI of 50% or more, and a field of view of 170 degrees or more and an RI of 30% or more can be realized.

[0116] According to an embodiment of the present invention, an optical system in which an image sensor has a horizontal viewing angle of 150 degrees or more, a diagonal viewing angle of 175 degrees or more, and an F number of 2.4 or less (for example, in the range of 1.4 to 2.4, for example, in the range of 1.8 to 2.3) can be obtained. At this time, the sensor length in the horizontal direction X may be 5.76 mm ± 0.5 mm, the sensor height in the vertical direction Y may be 4.46 mm ± 0.5 mm, and the sensor length in the diagonal direction may be 7.28 mm ± 0.5 mm. Therefore, the change in the focus imaging position due to temperature change can be suppressed, and a vehicle-mounted camera that well corrects various aberrations can be provided.

[0117] Table 1 is a table showing the chief ray angle (CRA) data and RI data according to the position of the image sensor in the optical system according to an embodiment of the present invention. Figure 8 is a graph showing the RI data according to the position of the image sensor in the optical system according to an embodiment of the present invention.

[0118] [Table 1]

[0119] Field of view CRA RI(%) 0 0.00 100.0％ 0.1 2.15 99.5％ 0.2 4.30 98.2％ 0.3 6.44 95.9％ 0.4 8.57 92.8％ 0.5 10.68 88.8％ 0.6 12.75 84.2％ 0.7 14.75 78.4％ 0.8 16.48 67.5％ 0.9 18.20 53.1％ 1 19.98 36.8％

[0120] Referring to Table 1 and Figure 8 , in the optical system according to an embodiment of the present invention, at a 1 field of view at the end of the diagonal length of the image sensor, the chief ray angle (CRA) 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. As Figure 8As shown, a graph of the relative illuminance according to the image height in an optical system according to an embodiment is shown. It can be seen that the relative illuminance ratio from the center to the end of the diagonal of the image sensor is 36% or more. Figures 9 to 11 is a graph showing Figure 1 the data of the diffraction modulation transfer function (MTF) of visible light of the optical system Figures 12 to 14 is a graph showing Figure 1 the data of the diffraction modulation transfer function (MTF) of IR light of the optical system Figure 1 at room temperature, low temperature, and high temperature. Table 2 shows Figure 1 the diffraction modulation transfer function (MTF) values of visible light of the optical system

[0121] [Table 2]

[0122]

[0123] [Table 3]

[0124]

[0125] Figures 9 to 11 is a graph showing Figure 1 the diffraction modulation transfer function (MTF) of visible light of the optical system Figures 9 to 11 at room temperature, low temperature, and high temperature, and is a graph showing the luminance ratio (modulation) according to the spatial frequency. As

[0126] Figures 12 to 14 is a graph showing Figure 1 the diffraction modulation transfer function (MTF) of IR light of the optical system Figures 12 to 14 at room temperature, low temperature, and high temperature, and is a graph showing the luminance ratio (modulation) according to the spatial frequency. As shown, it can be seen that in the embodiments of the present invention, the MTF deviation between low temperature and high temperature based on room temperature is low.

[0127] In Table 4, the changes in the optical characteristics of visible light such as EFL, BFL, F-number F#, TTL, and field of view (FOV) of the optical system according to an embodiment of the present invention at room temperature, low temperature, and high temperature are compared. In Table 5, the changes in the optical characteristics of IR light such as EFL, BFL, F-number F#, TTL, and field of view (FOV) of the optical system according to an embodiment of the present invention at room temperature, low temperature, and high temperature are compared.

[0128] [Table 4]

[0129] Room temperature (22 °C) Low temperature (-40 °C) High temperature (85 °C) EFL 2.15 2.14 2.16 BFL 5 4.98 5.01 F# 2.20 2.19 2.22 TTL 14 13.96 14.04 FOV 176 176.62 175.01

[0130] [Table 5]

[0131] Room temperature (22 °C) Low temperature (-40 °C) High temperature (85 °C) EFL 2.16 2.15 2.18 BFL 5 4.98 5.01 F# 2.20 2.19 2.22 TTL 14 13.96 14.04 FOV 174.94 175.78 173.75

[0132] Referring to Table 4 and Table 5, it can be seen that: not only in the visible light region but also in the IR light region, the rate of change of the optical properties at low temperature based on room temperature is 5% or less, for example, 3% or less, and the rate of change of the optical properties at high temperature based on room temperature is 5% or less, for example, 3% or less. In particular, since the difference in the temperature change between EFL and BFL remains constant, temperature compensation can be performed, thereby preventing a decrease in the reliability of the optical characteristics due to temperature changes.

[0133] The optical system 100 according to an embodiment of the present invention can satisfy at least one or two or more of the following expressions. Therefore, the optical system 100 according to an embodiment of the present invention can have improved optical characteristics. For example, when the optical system 100 according to an embodiment of the present invention satisfies at least one expression, the optical system 100 can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have excellent optical performance not only in the central part of the field of view (FOV) but also in its outer periphery. In addition, the optical system 100 can have improved resolution.

[0134] [Expression 1-1]

[0135] 1 < F LG1 / F LG2

[0136] [Expression 1-2]

[0137] 1.1 ≤ F LG1 / F LG2 ≤ 2

[0138] [Expression 1-3]

[0139] 1.1 ≤ F LG1 / F LG2 ≤ 1.5

[0140] [Expression 1-4]

[0141] 1.1 ≤ F LG1 / F LG2 ≤ 3

[0142] Here, F LG1 is the effective focal length of the first lens group, and F LG2 is the effective focal length of the second lens group. When Expressions 1-1 to 1-4 are satisfied, the first lens group can diffuse the light incident from the object side, and the second lens group can refract the light diffused by the first lens group into the area of the image sensor. When F LG1 / F LG2 is less than the lower limit or exceeds the upper limit of Expressions 1-1 to 1-4, the RI of the image sensor may be significantly reduced or the quality may deteriorate.

[0143] [Expression 2-1]

[0144] V3 < V1

[0145] [Expression 2-2]

[0146] V3 < V2

[0147] [Expression 2-3]

[0148] V5 < V4

[0149] [Expression 2-4]

[0150] V5 < V6

[0151] [Expression 2-5]

[0152] V3 = V5

[0153] Here, V1 is the Abbe number of the first lens 110, V2 is the Abbe number of the second lens 120, V3 is the Abbe number of the third lens 130, V4 is the Abbe number of the fourth lens 140, and V5 is the Abbe number of the fifth lens 150. When Expressions 2-1 to 2-5 are satisfied, the third lens 130 can eliminate the chromatic aberration of the first lens group, and the fifth lens 150 can eliminate the chromatic aberration of the second lens group.

[0154] [Expression 3-1]

[0155] 20 ≤ Vmax - Vmin ≤ 60

[0156] [Expression 3-2]

[0157] 25 ≤ Vmax - Vmin ≤ 50

[0158] [Expression 3-3]

[0159] 30 ≤ Vmax - Vmin ≤ 40

[0160] Here, Vmax is the maximum Abbe number among the first lens to the sixth lens, and Vmin is the minimum Abbe number among the first lens to the sixth lens. When the expressions 3-1 to 3-3 are satisfied, an image of high quality and high pixels can be obtained, and an optical system applicable to both visible light and IR light and applicable to temperature variations from -40°C to 85°C can be obtained. When Vmax - Vmin is less than the lower limit or exceeds the upper limit of the expressions 3-1 to 3-3, the optical characteristics may vary according to high and low temperature environments, making it difficult to apply to a wide range of temperature variations.

[0161] [Expression 4-1]

[0162] R6 / R7 ≤ -3

[0163] [Expression 4-2]

[0164] R6 / R7 ≤ -5

[0165] [Expression 4-3]

[0166] -10 ≤ R6 / R7 ≤ -8

[0167] Here, R6 is the radius of curvature of the image-side surface of the third lens 130, and R7 is the radius of curvature of the object-side surface of the fourth lens 140. When the expressions 4-1 to 4-3 are satisfied, the sensitivity between the image-side surface 132 of the third lens 130 and the object-side surface 141 of the fourth lens 140 can be improved, and the divergence angle can be reduced. When R6 / R7 is less than the lower limit or exceeds the upper limit of the expressions 4-1 to 4-3, the incident angle of the object-side surface 142 of the fourth lens 140 may increase, resulting in an increase in aberration.

[0168] [Expression 5-1]

[0169] 8mm ≤ ED L1S1

[0170] [Expression 5-2]

[0171] 8mm ≤ ED L1S1 ≤ 9.5mm

[0172] [Expression 5-3]

[0173] 8.5mm ≤ ED L1S1 ≤ 9mm

[0174] Here, ED L1S1is the effective diameter of the object-side surface of the first lens 110. When Expressions 5-1 to 5-3 are satisfied, the brightness of the optical system 100 can be increased by increasing the amount of light incident on the optical system 100, and the deterioration of the resolution and optical characteristics of the optical system 100 due to temperature changes can be compensated. When ED L1S1 is less than the lower limit of Expressions 5-1 to 5-3, the amount of light incident on the optical system decreases, making it difficult to achieve an ultra-wide-angle optical system. When ED L1S1 exceeds the upper limit, there is a problem that the size of the optical system increases.

[0175] [Expression 6-1]

[0176] 1.05 ≤ ED L1S1 / 2*H imageD ≤ 1.3

[0177] [Expression 6-2]

[0178] 1.1 ≤ ED L1S1 / 2*H imageD ≤ 1.2

[0179] [Expression 6-3]

[0180] 1.12 ≤ ED L1S1 / 2*H imageD ≤ 1.18

[0181] Here, H imageD is half of the diagonal length of the image sensor 180. When Expressions 6-1 to 6-3 are satisfied, the amount of light incident on the object-side surface 112 of the first lens 110 can be maximized within the range where the first lens 110 can be manufactured, and a field of view of more than 150 degrees can be achieved. When ED L1S1 / 2*H imageD is less than the lower limit of Expressions 6-1 to 6-3, it is difficult for a sufficient amount of light to reach the outer periphery of the image sensor at a field of view of more than 150 degrees. When ED L1S1 / 2*H imageD exceeds the upper limit, there are problems that it is difficult to manufacture the first lens and the size of the optical system 100 increases.

[0182] [Expression 7-1]

[0183] 0.4 ≤ ED L1S2 / 2*H imageD ≤ 0.7

[0184] [Expression 7-2]

[0185] 0.45 ≤ ED L1S2 / 2*H imageD≤0.65

[0186] [Expression 7-3]

[0187] 0.5ED L1S2 / 2*H imageD ≤0.6

[0188] Here, ED L1S2 is the effective diameter of the image-side surface 114 of the first lens 110. When Expressions 7-1 to 7-3 are satisfied, the field of view of the first lens 110 can be widened. When ED L1S2 / 2*H imageD is less than the lower limit or exceeds the upper limit of Expressions 7-1 to 7-3, it may be difficult to make sufficient light reach the outer periphery of the image sensor, or it may be difficult to achieve an FOV of more than 150 degrees.

[0189] [Expression 8-1]

[0190] 1.5≤ED L1S1 / ED L1S2 ≤3

[0191] [Expression 8-2]

[0192] 1.7≤ED L1S1 / ED L1S2 ≤2.6

[0193] [Expression 8-3]

[0194] 1.9≤ED L1S1 / ED L1S2 ≤2.3

[0195] When Expressions 8-1 to 8-3 are satisfied, the field of view of the first lens 110 can be widened. When ED L1S1 / ED L1S2 is less than the lower limit or exceeds the upper limit of Expressions 8-1 to 8-3, it may be difficult to make sufficient light reach the outer periphery of the image sensor, or it may be difficult to achieve an FOV of more than 150 degrees.

[0196] [Expression 9-1]

[0197] 3≤R1 / R2≤4.5

[0198] [Expression 9-2]

[0199] 3.25≤R1 / R2≤4.25

[0200] [Expression 9-3]

[0201] 3.5≤R1 / R2≤4

[0202] When the expressions 9-1 to 9-3 are satisfied, the field of view of the first lens 110 can be widened. When R1 / R2 is less than the lower limit or exceeds the upper limit of the expressions 9-1 to 9-3, it may be difficult to make sufficient light reach the outer periphery of the image sensor, or it may be difficult to achieve a FOV of more than 150 degrees.

[0203] [Expression 10-1]

[0204] 0.2 ≤ ED L1S1 / TTL ≤ 1

[0205] [Expression 10-2]

[0206] 0.4 ≤ ED L1S1 / TTL ≤ 0.8

[0207] [Expression 10-3]

[0208] 0.4 ≤ ED L1S1 / TTL ≤ 0.8

[0209] When ED L1S1 / TTL is less than the lower limit or exceeds the upper limit of the expressions 10-1 to 10-3, it is difficult to balance the overall size of the optical system 100 and it may not be easy to manufacture.

[0210] [Expression 11-1]

[0211] 1.2 ≤ ET1 / CT1 ≤ 3

[0212] [Expression 11-2]

[0213] 1.3 ≤ ET1 / CT1 ≤ 2.5

[0214] [Expression 11-3]

[0215] 1.5 ≤ ET1 / CT1 ≤ 2

[0216] Here, ET1 is the edge thickness of the first lens 110, and CT1 is the center thickness of the first lens 110. When the expressions 11-1 to 11-3 are satisfied, an ultra-wide-angle optical system with a field of view of more than 150 degrees and an RI of more than 50% and a field of view of more than 170 degrees and an RI of more than 30% can be achieved. When ET1 / CT1 is less than the lower limit of the expressions 11-1 to 11-3, it may be difficult to combine with the flange, and the risk of the first lens breaking may increase. When ET1 / CT1 exceeds the upper limit of the expressions 11-1 to 11-3, the productivity may decrease, and it may be difficult to combine with the flange.

[0217] [Expression 12-1]

[0218] -5 ≤ R3 / R2 ≤ -0.5

[0219] [Expression 12-2]

[0220] -3 ≤ R3 / R2 ≤ -0.5

[0221] [Expression 12-3]

[0222] -2 ≤ R3 / R2 ≤ -1

[0223] Here, R2 is the radius of curvature of the image-side surface 114 of the first lens 110, and R3 is the radius of curvature of the object-side surface 122 of the second lens 120. When Expressions 12-1 to 12-3 are satisfied, the influence of the ghost image of the first lens 110 and the second lens 120 on the entire optical system 100 can be minimized. When R3 / R2 is less than the lower limit or exceeds the upper limit of Expressions 12-1 to 12-3, a part of the light output from the image-side surface 114 of the first lens 110 may be lost, thereby reducing the imaging efficiency.

[0224] [Expression 13-1]

[0225] 0.25 ≤ CT3 / CT_16 ≤ 0.45

[0226] [Expression 13-2]

[0227] 0.28 ≤ CT3 / CT_16 ≤ 0.4

[0228] [Expression 13-3]

[0229] 0.3 ≤ CT3 / CT_16 ≤ 0.36

[0230] Here, CT3 is the center thickness of the third lens 130, and CT_16 is the sum of the center thicknesses of the first lens to the sixth lens. When Expressions 13-1 to 13-3 are satisfied, the third lens 130 can function in condensing light and correcting chromatic aberration, and maximize the amount of light incident on the aperture stop. When CT3 / CT_16 is less than the lower limit of Expressions 13-1 to 13-3, the third lens 130 cannot fully perform chromatic aberration correction, and when CT3 / CT_16 exceeds the upper limit, the amount of light incident through the aperture may decrease.

[0231] [Expression 14-1]

[0232] 2 ≤ CT3 / CT2 ≤ 10

[0233] [Expression 14-2]

[0234] 3 ≤ CT3 / CT2 ≤ 10

[0235] [Expression 14-3]

[0236] 3.5 ≤ CT3 / CT2 ≤ 10

[0237] Here, CT2 is the central thickness of the second lens 120. When Expressions 14-1 to 14-3 are satisfied, since it is easy to align the optical axes of the second lens 120 and the third lens 130, the assemblability can be improved. When CT3 / CT2 is less than the lower limit of Expressions 14-1 to 14-3, it is difficult to effectively eliminate chromatic aberration in the third lens 130. When CT3 / CT1 exceeds the upper limit, the overall size of the optical system 100 may increase excessively.

[0238] [Expression 15-1]

[0239] -1.02 ≤ f5 / f6 ≤ -0.95

[0240] [Expression 15-2]

[0241] -1.015 ≤ f5 / f6 ≤ -0.97

[0242] [Expression 15-3]

[0243] -1.015 ≤ f5 / f6 ≤ -0.98

[0244] Here, f5 is the effective focal length of the fifth lens 150, and f6 is the effective focal length of the sixth lens 160. When Expressions 15-1 to 15-3 are satisfied, the tolerance sensitivity and overall optical imaging performance of the optical system 100 can be improved, thereby improving productivity. When f5 / f6 is less than the lower limit or exceeds the upper limit of Expressions 15-1 to 15-3, the imaging performance may deteriorate because the proper ratio between the effective focal lengths of the fifth lens 150 and the sixth lens 160 is deviated.

[0245] [Expression 16-1]

[0246] 0.02 ≤ CG5 / (CT5 + CT6) ≤ 0.07

[0247] [Expression 16-2]

[0248] 0.04 ≤ CG5 / (CT5 + CT6) ≤ 0.065

[0249] [Expression 16-3]

[0250] 0.05 ≤ CG5 / (CT5 + CT6) ≤ 0.06

[0251] Here, CG5 is the center distance between the fifth lens 150 and the sixth lens 160, CT5 is the center thickness of the fifth lens 150, and CT6 is the center thickness of the sixth lens 160. When Expressions 16-1 to 16-3 are satisfied, the tolerance sensitivity and overall optical imaging performance of the optical system 100 can be improved, thereby improving productivity. When CG5 / (CT5 + CT6) is less than the lower limit or exceeds the upper limit of Expressions 16-1 to 16-3, the imaging performance may deteriorate due to the deteriorated assemblability of the optical system 100 and the deviation from the appropriate ratio between the effective focal length of the fifth lens 150 and the effective focal length of the sixth lens 160.

[0252] [Expression 17-1]

[0253] 1.5 ≤ F456 / F ≤ 1.665

[0254] [Expression 17-2]

[0255] 1.55 ≤ F456 / F ≤ 1.665

[0256] [Expression 17-3]

[0257] 1.6 ≤ F456 / F ≤ 1.665

[0258] Here, F456 is the combined effective focal length of the fourth lens to the sixth lens, and F is the total effective focal length of the optical system 100. When Expressions 17-1 to 17-3 are satisfied, the tolerance sensitivity and overall optical imaging performance of the optical system 100 can be improved, thereby improving productivity. When F456 / F is less than the lower limit or exceeds the upper limit of Expressions 17-1 to 17-3, the assemblability of the optical system 100 may deteriorate, and the imaging performance may deteriorate.

[0259] [Expression 18-1]

[0260] 1.3 ≤ TTL / 2*H imageD ≤ 2.5

[0261] [Expression 18-2]

[0262] 1.5 ≤ TTL / 2*H imageD ≤ 2.3

[0263] [Expression 18-3]

[0264] 1.8 ≤ TTL / 2*H imageD ≤ 2.1

[0265] When Expressions 18-1 to 18-3 are satisfied, a vehicle-mounted optical system with an effective focal length of 2 mm or more and a field of view of 150 degrees or more can be obtained. When TTL / 2*HimageD When it is less than the lower limit of Expression 18-1 to Expression 18-3, it may be difficult to obtain an effective focal length of more than 2 mm, when TTL / 2*H imageD When it exceeds the upper limit, the total length of the optical system may become too large.

[0266] [Expression 19-1]

[0267] 6 ≤ TTL / F ≤ 7

[0268] [Expression 19-2]

[0269] 6.2 ≤ TTL / F ≤ 6.8

[0270] [Expression 19-3]

[0271] 6.4 ≤ TTL / F ≤ 6.6

[0272] When Expression 19-1 to Expression 19-3 are satisfied, an in-vehicle optical system with an effective focal length of more than 2 mm and a field of view of more than 150 degrees can be obtained. When TTL / F is less than the lower limit of Expression 19-1 to Expression 19-3, it may be difficult to obtain a field of view of more than 150 degrees, and when TTL / F exceeds the upper limit, the total length of the optical system may become too large.

[0273] [Expression 20-1]

[0274] 0.35 ≤ BFL / TTL ≤ 0.5

[0275] [Expression 20-2]

[0276] 0.37 ≤ BFL / TTL ≤ 0.48

[0277] [Expression 20-3]

[0278] 0.4 ≤ BFL / TTL ≤ 0.45

[0279] When Expression 20-1 to Expression 20-3 are satisfied, since not only a compact and lightweight optical system 100 can be obtained, but also the distance BFL between the image side surface 164 of the sixth lens 160 and the image sensor 180 can be guaranteed, the assemblability and productivity of the optical system 100 can be improved, and the RI of the image sensor 180 can be improved. When BFL / TTL is less than the lower limit of Expression 20-1 to Expression 20-3, the assemblability of the optical system 100 may be limited, and when BFL / TTL exceeds the upper limit, the RI of the image sensor 180 may decrease.

[0280] [Expression 21]

[0281] 1.01 ≤ D23_max / CG2 ≤ 4

[0282] Here, D23_max is the maximum distance between the second lens 120 and the third lens 130, and CG2 is the center distance between the second lens 120 and the third lens 130. When Expression 21 is satisfied, since the air gap on the object side surface 132 side of the third lens 130 that functions in chromatic aberration correction is minimized, and the light output from the image side surface 124 of the second lens 120 is incident on the object side surface 132 of the third lens 130 almost perpendicularly, the light can be refracted uniformly within the third lens 130, and the chromatic aberration correction performance of the third lens can be maximized. When D23_max / CG2 is less than the lower limit of Expression 21, it is difficult to assemble the optical system. When D23_max / CG2 exceeds the upper limit of Expression 21, it is difficult for the light to be refracted uniformly within the third lens 130. Therefore, the chromatic aberration correction performance of the third lens 130 may be reduced.

[0283] [Expression 22]

[0284] 1.01 ≤ D45_max / CG4 ≤ 4

[0285] Here, D45_max is the maximum distance between the fourth lens 140 and the fifth lens 150, and CG2 is the center distance between the fourth lens 140 and the fifth lens 150. When Expression 22 is satisfied, since the air gap on the object side surface 152 side of the fifth lens 150 that functions in chromatic aberration correction is minimized, and the light output from the image side surface 144 of the fourth lens 140 is incident on the object side surface 152 of the fifth lens 150 almost perpendicularly, the light can be refracted uniformly within the fifth lens 150, and the chromatic aberration correction performance of the fifth lens 150 can be maximized. When D45_max / CG4 is less than the lower limit of Expression 22, it is difficult to assemble the optical system. When D45_max / CG4 exceeds the upper limit of Expression 22, it is difficult for the light to be refracted uniformly within the fifth lens 150. Therefore, the chromatic aberration correction performance of the fifth lens 150 may be reduced.

[0286] [Expression 23-1]

[0287] 1 mm ≤ |maxsag11|

[0288] [Expression 23-2]

[0289] 1 mm ≤ |maxsag12|

[0290] Here, maxsag11 is the maximum sag value of the object-side surface 112 of the first lens 110, and maxsag12 is the maximum sag value of the image-side surface 114 of the first lens 110. When the expressions 23-1 and 23-2 are satisfied, an ultra-wide-angle optical system of more than 150 degrees can be achieved. When |maxsag11| or |maxsag12| is less than the lower limit of the expressions 23-1 and 23-2, it may be difficult to achieve an ultra-wide-angle optical system of more than 150 degrees.

[0291] [Expression 24-1]

[0292] 0.9 ≤ |P2| / |P3| ≤ 1.1

[0293] [Expression 24-2]

[0294] 0.915 ≤ |P2| / |P3| ≤ 1

[0295] [Expression 24-3]

[0296] 0.93 ≤ |P2| / |P3| ≤ 0.98

[0297] Here, P2 is the refractive power of the second lens 120, and P3 is the refractive power of the third lens 130. As described above, the second lens 120 has a negative refractive power, and the third lens 130 has a positive refractive power. When the refractive powers of the second lens 120 and the third lens 130 satisfy the expressions 24-1 to 24-3, the chromatic aberration cancellation effect of the third lens 130 can be improved. When |P2| / |P3| is less than the lower limit or exceeds the upper limit of the expressions 24-1 to 24-3, light may not be refracted effectively in the third lens 130, so the chromatic aberration cancellation performance may be reduced.

[0298] [Expression 25-1]

[0299] 0.7 ≤ |P4| / |P5| ≤ 1

[0300] [Expression 25-2]

[0301] 0.75 ≤ |P4| / |P5| ≤ 0.9

[0302] [Expression 25-3]

[0303] 0.78 ≤ |P4| / |P5| ≤ 0.85

[0304] Here, P4 is the refractive power of the fourth lens 140, and P5 is the refractive power of the fifth lens 150. As described above, the fourth lens 140 has a negative refractive power, and the fifth lens 150 has a positive refractive power. When the refractive powers of the fourth lens 140 and the fifth lens 150 satisfy Expressions 25-1 to 25-3, the chromatic aberration elimination effect of the fifth lens 150 can be improved. When |P4| / |P5| is less than the lower limit or exceeds the upper limit of Expressions 25-1 to 25-3, light may not be effectively refracted in the fifth lens 150, and thus the chromatic aberration elimination performance may be reduced.

[0305] Figure 15 is an example of a plan view of a vehicle to which an optical system according to an embodiment of the present invention or a camera device including the optical system is applied.

[0306] Referring to Figure 15 , the in-vehicle camera system according to an embodiment of the present invention includes an image generation unit 11, a first information generation unit 12, second information generation units 21, 22, 23, 24, 25, and 26, and a control unit 14. The image generation unit 11 may include at least one camera module 31 provided in the vehicle, and the image generation unit 11 may capture an image of the front of the vehicle and / or the driver to generate an image of the front of the vehicle or the interior of the vehicle. The image generation unit 11 may generate an image of the surroundings of the vehicle and the front of the vehicle by capturing the surroundings of the vehicle and the front of the vehicle in one or more directions using the camera device 31. Here, the front image and the surrounding image may be digital images, and may include color images, black-and-white images, infrared images, etc. In addition, the front image and the surrounding image may include still images and moving images. The image generation unit 11 may provide the driver image, the front image, and the surrounding image to the control unit 14. Secondly, the first information generation unit 12 may include at least one radar and / or camera provided in the vehicle, and detect the front of the vehicle to generate first detection information. Specifically, the first information generation unit 12 may be provided in the vehicle, and may detect the position and speed of the vehicle located in front of the vehicle and the presence and position of pedestrians, etc., to generate first detection information.

[0307] Using the first detection information generated by the first information generation unit 12, the distance between the vehicle and the vehicle ahead can be controlled to remain at a constant level, and in specific preset situations, for example, when the driver wants to change the driving lane of the vehicle or when reverse parking, the stability of vehicle operation can be increased. The first information generation unit 12 can provide the first detection information to the control unit 14. The second information generation units 21, 22, 23, 24, 25, and 26 can detect each side of the vehicle and generate second detection information based on the front image generated in the image generation unit 11 and the first detection information generated in the first information generation unit 12. Specifically, the second information generation units 21, 22, 23, 24, 25, and 26 can include at least one radar and / or camera provided in the vehicle, and can detect the position and speed of the vehicle located on the side of the vehicle or capture an image. Here, the second information generation units 21, 22, 23, 24, 25, and 26 can be provided at the front corners, side mirrors, rear center, and rear corners of the host vehicle.

[0308] At least one information generation unit of these in-vehicle camera systems can include the optical system described in the above embodiments and a camera module having the optical system, and use the information obtained through the front, rear, each side, or corner area of the vehicle to provide the information to the user or process the information to protect the vehicle and objects from the impact of autonomous driving or surrounding safety.

[0309] The multiple optical systems of the camera device according to an embodiment of the present invention can be installed in a vehicle for safety regulations, enhancing autonomous driving capabilities, and increasing convenience. In addition, the optical system of the camera device can be applied to the vehicle as a control component such as a lane keeping assist system (LKAS), a lane departure warning system (LDWS), and a driver monitoring system (DMS). Such a vehicle camera module can achieve stable optical performance even under changing ambient temperatures and provide a price-competitive module, thereby ensuring the reliability of vehicle components.

[0310] The features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. In addition, the features, structures, effects, etc. shown as examples in each embodiment can be combined or modified by those of ordinary skill in the art to which the embodiment belongs in other embodiments and implemented. Therefore, the content related to these combinations and modifications should be interpreted as being included within the scope of the present invention.

[0311] In addition, although the above has been described mainly by way of examples, these are merely examples and do not limit the present invention. Those of ordinary skill in the art to which the present invention pertains will recognize that various modifications and applications not shown above as examples can be made without departing from the basic features of the present invention. For example, each component specifically shown in the examples can be modified and implemented. In addition, the differences associated with these modifications and applications should be construed as being included within the scope of the present invention defined in the appended claims.

[0312] [Reference Signs]

[0313] 110: First lens 120: Second lens

[0314] 130: Third lens 140: Fourth lens

[0315] 150: Fifth lens 160: Sixth lens

[0316] 170: Filter 180: Image sensor

[0317] 190: Cover glass

Claims

1. An optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and an image sensor sequentially arranged from the object side to the image side. Among them, The first lens has a negative refractive power, the second lens has a negative refractive power, the third lens has a positive refractive power, the fourth lens has a positive refractive power, the fifth lens has a negative refractive power, and the sixth lens has a positive refractive power. An aperture is disposed between the third lens and the fourth lens. The first lens to the third lens have a negative combined refractive power, and The fourth lens to the sixth lens have a positive combined refractive power.

2. The optical system according to claim 1, wherein The image-side surface of the third lens is concave, and the object-side surface of the fourth lens is concave.

3. The optical system according to claim 2, wherein The ratio (R6 / R7) of the radius of curvature R6 of the image-side surface of the third lens to the radius of curvature R7 of the object-side surface of the fourth lens is -3 or less.

4. The optical system according to claim 1, wherein, The effective diameter of the object-side surface of the first lens is 8 mm or more and 9.5 mm or less.

5. The optical system according to claim 1, wherein, The effective diameter of the object-side surface of the first lens is greater than the diagonal length of the image sensor, and the effective diameter of the image-side surface of the first lens is less than the diagonal length of the image sensor.

6. The optical system according to claim 5, wherein, The ratio of the effective diameter of the object-side surface of the first lens to the diagonal length of the image sensor is 1.05 or more and 1.3 or less, and the ratio of the effective diameter of the image-side surface of the first lens to the diagonal length of the image sensor is 0.4 to 0.

7.

7. The optical system according to claim 1, wherein, At least one of the object-side surface and the image-side surface of the second lens includes a critical point with an inclination angle of 0, and The inclination angle of the image-side surface of the first lens in a region more than four times the distance from the optical axis to the critical point is 30 degrees or more.

8. The optical system according to claim 1, wherein, The ratio of the edge thickness of the first lens to the center thickness of the first lens is 1.2 or more and 3 or less.

9. The optical system according to claim 1, wherein, Among the first distance between the first lens and the second lens, the second distance between the second lens and the third lens, the third distance between the third lens and the fourth lens, the fourth distance between the fourth lens and the fifth lens, and the fifth distance between the fifth lens and the sixth lens, the second distance is the smallest.

10. The optical system according to claim 9, wherein, The fourth distance is the next smallest distance after the second distance.

Images