Optical system and camera module comprising the same

Abstract

An optical system provided in an embodiment of the present invention can include first to sixth lenses arranged from an object toward a sensor side along an optical axis. The first lens can have a negative (-) refractive power on the optical axis. An object side surface of the first lens can have a convex shape on the optical axis. An object side surface of the second lens can have a convex shape on the optical axis. An optical axis interval between the second lens and the third lens can be greater than an optical axis interval between the first lens and the second lens.

Description

Technical Field

[0001] Embodiments of the present invention relate to an optical system for improving optical performance and a camera device module including the optical system. Background Technology

[0002] Camera module performs the function of capturing objects and storing them as images or moving images, and is installed in various applications. In particular, camera module is manufactured in an ultra-small size and is used not only in portable devices such as smartphones, tablet PCs, and laptops, but also in drones, vehicles, etc., thus providing a variety of functions. For example, the optical system of the camera module may include an imaging lens that forms an image and an image sensor that converts the formed image into an electrical signal. In this case, the camera module can perform an autofocus (AF) function by automatically adjusting the distance between the image sensor and the imaging lens to align the focal length of the lens; and can perform a zoom function by simultaneously increasing or decreasing the magnification of a distant object through a zoom lens to capture the distant object. Furthermore, the camera module employs image stabilization (IS) technology to compensate for or prevent image jitter caused by camera movement due to unstable fixtures or user movement.

[0003] For such a camera module to acquire an image, the most crucial component is the imaging lens that forms the image. Recently, there has been increasing focus on high resolution, and research has been conducted on optical systems incorporating multiple lenses to achieve this. For example, research has been conducted on using multiple imaging lenses with positive (+) or negative (-) refractive power to achieve high resolution. However, when multiple lenses are included, it becomes difficult to obtain excellent optical and aberration characteristics. Furthermore, when multiple lenses are included, the total length, height, etc., may increase due to the thickness, distance, and size of the multiple lenses, thus increasing the overall size of the module. In addition, the size of image sensors is increasing to achieve high resolution and high image quality. However, as the size of image sensors increases, the total TTL track length of the optical system including multiple lenses also increases, thus increasing the thickness of the camera device, mobile terminal, etc., that includes this optical system. Therefore, a new optical system capable of solving the above problems is needed. Summary of the Invention

[0004] Technical issues

[0005] The embodiments of the present invention aim to provide an optical system with improved optical properties. Embodiments of the present invention can provide an optical system in which lenses made of glass and plastic materials are combined, and a camera module having such an optical system. Embodiments of the present invention can provide an optical system capable of protecting a plastic lens by placing a glass lens on the object side, and a camera module having such an optical system. This embodiment aims to provide an optical system with excellent optical performance in both the central and peripheral portions of the field of view. This embodiment aims to provide an optical system capable of reducing deviations in optical properties caused by thermal changes.

[0006] Technical solutions

[0007] According to an embodiment of the present invention, the camera device module includes: a first lens to a sixth lens disposed along the optical axis from the object toward the sensor side, wherein the first lens may have a negative (-) refractive force on the optical axis, the object-side surface of the first lens may have a convex shape on the optical axis, the object-side surface of the second lens may have a convex shape on the optical axis, and the optical axis distance between the second lens and the third lens may be greater than the optical axis distance between the first lens and the second lens.

[0008] According to an embodiment of the present invention, the center thickness of the sixth lens may be the largest among the center thicknesses of the first to sixth lenses. The third lens may have positive refractive power along the optical axis. The center thickness of the second lens may be greater than the center thickness of the first lens. The refractive index of the third lens may be the largest among the refractive indices of the first to sixth lenses. At least two of the first to sixth lenses may be made of glass, and the center thickness of the first lens may be less than the center thickness of the lens disposed between the lenses made of glass. The first and third lenses may be made of glass, and the second, fourth, fifth, and sixth lenses may be made of plastic.

[0009] According to an embodiment of the present invention, the second and third lenses may each have a meniscus shape convex toward the object along the optical axis. The center thickness of the fifth lens may be the smallest among the center thicknesses of the first to sixth lenses. The effective length of each of the object-side surface and sensor-side surface of each of the third to sixth lenses may be less than the diagonal length of the image sensor.

[0010] An optical system according to an embodiment of the present invention includes: a first lens group comprising a first lens and a second lens disposed along an optical axis from an object toward a sensor side; a second lens group disposed on the sensor side of the first lens group and comprising a third to a sixth lens aligned along an optical axis from an object toward a sensor side; and an aperture stop disposed around a region between the third and fourth lenses, wherein the optical power of the first lens group may have a negative (-) value, and the optical axis distance between the second and third lenses may be greater than the optical axis distance between the first and second lenses.

[0011] According to an embodiment of the present invention, the first lens may have negative (-) refractive power and may have the largest focal length among the first to sixth lenses, and the sixth lens may have positive (+) refractive power. The first lens may have a meniscus shape convex toward the object on the optical axis, and the effective length of the first lens may be the largest among the effective lengths of the first to sixth lenses.

[0012] According to an embodiment of the present invention, the optical axis distance between the second lens and the third lens can be CG2, the center thickness of the sixth lens can be CT6, and it can satisfy the following formula: The optical axis distance between the second and third lenses can be CG2, and the optical axis distance between the first and second lenses can be CG1, and can satisfy the following formula: .

[0013] According to an embodiment of the present invention, the optical axis distance from the sensor-side surface of the sixth lens to the image plane of the image sensor can be BFL, the center thickness of the sixth lens can be CT6, and it can satisfy the following formula: 0.5 The maximum value among the center thicknesses of the first to sixth lenses can be CT_Max, and the maximum value among the optical axis distances between adjacent lenses can be CG_Max, and both can satisfy the following formula: .

[0014] According to an embodiment of the present invention, any one of the lenses in the first lens group may comprise a glass material, and at least one lens in the second lens group may be made of a glass material. The third lens may be a lens made of glass material and may have the largest refractive index among the first to sixth lenses. The optical power of the second lens group may have a positive (+) value, the focal lengths of the third, fourth, fifth, and sixth lenses may be F3, F4, F5, and F6, respectively, and the average value of the focal lengths of the third, fourth, fifth, and sixth lenses may satisfy the following formula: .

[0015] Beneficial effects

[0016] According to an embodiment of the present invention, in a lens of an optical system for moving an object, a glass lens is disposed adjacent to the object side of a plastic lens, thereby providing an effect of preventing cracking or yellowing caused by ultraviolet radiation. Furthermore, by incorporating both a plastic lens and a glass lens in the optical system, price competitiveness can be improved. According to an embodiment of the present invention, the glass lens disposed closest to the object can be made of a material with low ultraviolet transmittance, thereby preventing cracking or yellowing in the plastic lens. The optical system and camera module according to the embodiment can have improved optical characteristics. Specifically, since the optical system is configured with the surface shape, refractive power, and thickness of multiple lenses and the distance between adjacent lenses, the optical system can have improved aberration characteristics and resolution. The optical system and camera module according to the embodiment can have improved distortion and aberration control characteristics and can have good optical performance in both the central and peripheral portions of the field of view (FOV). Furthermore, the reliability of the optical system and camera module for vehicles can be improved. Attached Figure Description

[0017] Figure 1 This is a configuration diagram of the optical system and camera device module according to the first embodiment of the present invention.

[0018] Figure 2 It is shown Figure 1 A table of lens data for an optical system.

[0019] Figure 3 It shows Figure 1 Examples of the aspherical coefficients of lenses in optical systems.

[0020] Figure 4 It is shown Figure 1 A graph of the diffraction MTF (modulation transfer function) data of the optical system.

[0021] Figure 5 It is shown Figure 1 The curves showing the aberration characteristics of the optical system.

[0022] Figure 6 It shows the basis Figure 1 A table of lens data for the second embodiment of the optical system.

[0023] Figure 7 It shows Figure 6 Examples of the aspherical coefficients of lenses.

[0024] Figure 8 It shows having Figure 6 A graph of the diffraction MTF data of the optical system with lens data.

[0025] Figure 9 It shows having Figure 6 A graph showing the aberration characteristics of the optical system based on lens data.

[0026] Figure 10 It shows the basis Figure 1 A table of lens data for the third embodiment of the optical system.

[0027] Figure 11 It shows Figure 10 Examples of the aspherical coefficients of lenses.

[0028] Figure 12 It shows having Figure 10 A graph of the diffraction MTF data of the optical system with lens data.

[0029] Figure 13 It shows having Figure 10 A graph showing the aberration characteristics of the optical system based on lens data.

[0030] Figure 14 This is a graph comparing the distortion characteristics according to an embodiment of the present invention.

[0031] Figure 15 This is a perspective view of a moving object having a camera device module according to an embodiment of the present invention.

[0032] Figure 16 This is a perspective view of a mobile terminal that uses a camera device module according to an embodiment of the present invention. Detailed Implementation

[0033] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The spirit of the invention is not limited to the embodiments described, but can be implemented in various other forms, and one or more components can be selectively combined and substituted within the scope of the spirit of the invention. Furthermore, the terminology used in the embodiments of the invention (including technical and scientific terms), unless specifically defined and explicitly described, can be interpreted in the sense that is generally understood by one of ordinary skill in the art to which this invention pertains, and commonly used terms, such as those defined in dictionaries, should be interpreted in light of the context of the relevant art.

[0034] The terminology used in embodiments of the present invention is for illustrative purposes and is not intended to limit the invention. In this specification, singular forms may also include plural forms unless specifically stated otherwise in the phrase, and where a statement of at least one (or more) of A and / or B, C may include one or more of all combinations that can be combined with A, B, and C. When describing components of embodiments of the invention, terms such as first, second, A, B, (a), and (b) may be used. Such terms are merely for distinguishing components from other components and should not determine the nature, order, or process of the corresponding constituent elements. Furthermore, when describing a component as “connected,” “coupled,” or “joined” to another component, the description may include not only direct connection, coupling, or joining to another component, but also connection, coupling, or joining between the component and another component via another component. When described as being formed or disposed “above” or “below” each component, the description includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or disposed between the two components. Additionally, when expressed as "above" or "below", it can refer to the downward or upward direction relative to a component.

[0035] In the description of this invention, "object-side surface" can mean the surface of the lens facing the object side relative to the optical axis OA, and "sensor-side surface" can mean the surface of the lens facing the imaging surface (image sensor) relative to the optical axis. A convex surface of the lens can mean that the surface has a convex shape on the optical axis or in the paraxial region, and a concave surface of the lens can mean that the surface has a concave shape on the optical axis or in the paraxial region. The radius of curvature, center thickness, and distance between lenses described in the lens data table refer to values ​​on the optical axis, and their units are mm. Vertical direction can mean a direction perpendicular to the optical axis, and the end of the lens or lens surface can mean the end of the effective area of ​​the lens through which the incident light passes. The effective length of the lens surface may be up to approximately [missing information - likely a measurement method or similar]. A measurement error of 0.4 mm. The paraxial region refers to a very narrow area near the optical axis, and is the area where the distance between the light ray and the optical axis OA is essentially zero. In the following description, the concave or convex shape of the lens surface will be referred to with respect to the optical axis, and may also include the paraxial region.

[0036] Figure 1 This is a configuration diagram of an optical system and camera device module according to an embodiment of the present invention.

[0037] Reference Figure 1The optical system 1000 or camera module may include a lens unit 100 having multiple lenses. The lenses of the lens unit 100 may be divided into multiple lens groups LG1 and LG2. For example, the lens unit 100 may include a first lens group LG1 disposed on the object side and a second lens group LG2 disposed on the sensor side of the first lens group LG1. Each lens group in the first lens group LG1 and the second lens group LG2 may include at least one lens, for example, at least two lenses. The number of lenses in the second lens group LG2 may be greater than the number of lenses in the first lens group LG1, and for example, may be in the range of 1.5 to 2.5 times the number of lenses in the first lens group LG1.

[0038] The first lens group LG1 may include two or fewer lenses. For example, the first lens group LG1 may include two lenses. The first lens group LG1 may include a glass lens and a plastic lens, and the glass lens may be disposed on the object side of the plastic lens. Therefore, the glass lens of the first lens group LG1 can block the external exposure of the plastic lens and protect the plastic lens from external heat or impact. That is, the object-side first lens 101 of the first lens group LG1 may be made of a glass material with low ultraviolet transmittance, thereby preventing cracking or yellowing in the plastic lens. The second lens group LG2 may include three or more, but five or fewer lenses. The second lens group LG2 may include a plastic lens and at least one glass lens. Among the lenses of the second lens group LG2, the lens closest to the first lens group LG1 may be made of glass material and can protect the adjacent lens made of plastic material. The second lens group LG2 may, for example, include four lenses.

[0039] Optical system 1000 may include eight or fewer lenses, or seven or fewer lenses. A first lens group LG1 may include a first lens 101 and a second lens 102, and a second lens group LG2 may include a third lens 103 through a sixth lens 106. In optical system 1000, the number of glass lenses may be less than the number of plastic lenses.

[0040] The total trace length (TTL) of the optical system 1000 can be 1.5 times or more the diagonal length of the image sensor 190, and for example, it can be in the range of 1.5 to 3 times or in the range of 2 to 3 times. TTL is the distance along the optical axis OA from the object-side surface of the first lens 101 closest to the object to the image surface of the image sensor 190. ImgH is half the diagonal length of the effective area of ​​the image sensor 190. The first lens group LG1 can have negative (-) refractive power (or optical power). The second lens group LG2 can have a refractive power with a sign opposite to that of the first lens group LG1. The second lens group LG2 can have positive (+) refractive power or positive optical power. The first lens group LG1 and the second lens group LG2 can have different focal lengths to achieve good optical performance in both the central and peripheral portions of the field of view (FOV). Refractive power is optical power and is the reciprocal of focal length. When the focal length is expressed in absolute value, the focal length of the first lens group LG1 can be less than the focal length of the second lens group LG2. The focal length of the second lens group LG2 can be less than five times the focal length of the first lens group LG1, for example, four times or less, or two times or less, the focal length of the first lens group LG1. Therefore, the optical system 1000 according to the embodiment can have improved aberration control characteristics, such as chromatic aberration and distortion aberration, by controlling the refractive power and focal length of each lens group in lens groups LG1 and LG2, and can have good optical performance in the central and peripheral portions of the field of view (FOV).

[0041] The first lens group LG1 may include lenses with a meniscus shape convex toward the object. At least one or all of the lenses in the first lens group LG1 may have object-side and sensor-side surfaces configured to have no critical points from the optical axis to the end of the effective region. Therefore, since the lenses in the first lens group LG1 do not have critical points, the effective length of the lenses in the second lens group LG2 may not be significantly increased. In the two lens surfaces facing each other in the first lens group LG1 and the second lens group LG2, for example, the sensor-side surface of the first lens group LG1 may be concave along the optical axis, and the object-side surface of the second lens group LG2 may be convex along the optical axis. The two lenses facing each other in the first lens group LG1 and the second lens group LG2 may be made of different materials, may have a center thickness of 2 mm or less, and may have refractive forces of opposite signs. The first lens group LG1 may refract light incident through the object side, causing the light to converge, and the second lens group LG2 may refract light exiting through the first lens group LG1 toward the peripheral portion of the image sensor 190.

[0042] In the first lens group LG1 and the second lens group LG2, the lens with the maximum effective length can be disposed in the first lens group LG1, and the lens with the minimum effective length can be disposed in the second lens group LG2. In the first lens group LG1 and the second lens group LG2, the lens with the maximum refractive index can be disposed in the second lens group LG2. In the first lens group LG1 and the second lens group LG2, the lens with the maximum center thickness can be disposed in the second lens group LG2. When the object-side surface or sensor-side surface of the lens has a circular or non-circular shape, the object-side surface or sensor-side surface of the lens can be defined by the effective length, and the effective length represents the maximum effective length in the direction perpendicular to the optical axis.

[0043] The first lens group LG1 may include lenses made of glass and lenses made of plastic. The first lens group LG1 may include spherical lenses and aspherical lenses. The second lens group LG2 may include lenses made of glass and lenses made of plastic, and the number of aspherical lenses may be greater than the number of spherical lenses. In the spherical lenses, the object-side surface and the sensor-side surface may have a spherical shape on the optical axis, and in the aspherical lenses, the object-side surface and the sensor-side surface may have an aspherical shape on the optical axis. The aspherical surface may include a freeform surface. At least one of the lenses in the first lens group LG1 and at least one of the lenses in the second lens group LG2 may be made of glass. Because at least one lens made of glass is provided in the lens unit 100, thermal compensation can be achieved, and the degradation of optical properties due to temperature changes can be prevented. In the optical system 1000, of the at least three lenses adjacent to the object, at least two lenses may be made of glass, and therefore, thermal compensation in the region adjacent to the object can be achieved.

[0044] On the optical axis OA, the first lens group LG1 and the second lens group LG2 can have a predetermined distance between them. The optical axis distance CG2 between the first lens group LG1 and the second lens group LG2 on the optical axis OA is the separation distance on the optical axis OA, and can be the optical axis distance between the sensor-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. The optical axis distance CG2 between the first lens group LG1 and the second lens group LG2 can be greater than the center thicknesses CT1 and CT2 of the first lens 101 and the second lens 102 of the first lens group LG1, and can be greater than the center thickness CT3 of the object-side third lens 103 of the second lens group LG2.

[0045] In the first lens group LG1, the effective length of the lens adjacent to the object can be greater than the average effective length of the second lens group LG2, and can be the largest among the lens units 100. In the optical system 1000, the lens with the largest effective length is a glass lens. In the optical system 1000, the lens with the smallest effective length is a plastic lens. The effective length of each lens is the average of the effective length of the corresponding lens's object-side surface and the effective length of its sensor-side surface. In the optical system, the lens with the largest effective length is the first lens 101. Therefore, the optical system 1000 can increase the amount of incident light, achieve good optical performance in both the central and peripheral portions of the field of view (FOV), and improve thermal compensation, chromatic aberration, and distortion aberrations.

[0046] When multiple lenses in the optical system 1000 are used by combining plastic and glass lenses, the cost can be reduced compared to a configuration made entirely of glass, and the optical path can be easily controlled using aspherical lenses. However, plastic lenses can expand or contract depending on temperature changes, which can affect their optical properties. Furthermore, plastic lenses are susceptible to high-temperature environments and may be affected by ultraviolet (UV) light in terms of optical performance. For example, cracks may appear in the material of a plastic lens due to UV light, or it may be damaged due to yellowing. Such cracks or yellowing in a plastic lens can cause changes in the refractive index and transmittance of the corresponding lens, thus affecting its optical performance. Therefore, when using plastic lenses, glass lenses can be positioned closer to the object side to block UV light, and the degradation of optical performance due to thermal changes can be suppressed using two or more glass lenses.

[0047] In the first lens group LG1, the lens closest to the object can have a negative (-) refractive power, and in the second lens group LG2, the lens closest to the image sensor 190, i.e., the last lens, can have a positive (+) refractive power. In the optical system 1000, the number of lenses with positive (+) refractive power can be equal to the number of lenses with negative (-) refractive power. In the second lens group LG2, the number of lenses with positive (+) refractive power can be greater than the number of lenses with negative (-) refractive power. Therefore, the resolution can be improved by utilizing the refractive power of each lens, as well as the positive and negative focal lengths.

[0048] Each of a plurality of lenses may include an effective region and an ineffective region. The effective region can be the area through which light incident on each lens passes. That is, the effective region can be a region with an effective diameter or effective length, in which incident light is refracted to achieve optical properties. An ineffective region may be disposed around the effective region. The ends of the effective region can be defined as edges or end portions. An ineffective region can be an area in the plurality of lenses where effective light is not incident. That is, an ineffective region can be a region unrelated to optical properties. Furthermore, the end portions of the ineffective region can be areas fixed to a lens barrel (not shown) that houses the lens.

[0049] The optical system 1000 may include an image sensor 190. The image sensor 190 can detect light and convert the detected light into an electrical signal. The image sensor 190 can detect light passing sequentially through multiple lenses 100. The image sensor 190 can be any of a CCD (charge-coupled device), CMOS (complementary metal-oxide-semiconductor), CPD, and CID, and may include elements capable of detecting incident light. The image sensor 190 may be an RGB red, green, and blue sensor for acquiring color images. Furthermore, when multiple image sensors 190 are arranged, the image sensor 190 may include an RGB image sensor and a monochrome image sensor. The diagonal length of the image sensor 190 may exceed 6 mm, for example, it may be greater than 6 mm and less than 20 mm. Preferably, the diagonal length of the image sensor 190 may be less than the TTL (Time To Live). Furthermore, the diagonal length of the image sensor 190 may be less than the effective focal length (EFL) of the optical system 1000.

[0050] The optical system 1000 may include an optical filter 192 disposed between the lens unit 100 and the image sensor 190. The optical filter 192 may be disposed between the second lens group LG2 and the image sensor 190. The optical filter 192 may be disposed between the lens closest to the sensor side among the plurality of lenses 100 and the image sensor 190. For example, when the optical system 100 includes six lenses, the optical filter 192 may be disposed between the sixth lens 106 (which is the last lens) and the image sensor 190. Figure 2 In this context, IR stands for optical filter. Optical filter 192 can filter light corresponding to a specific wavelength range from light that has already passed through lens unit 100. Optical filter 192 can be an infrared (IR) cutoff filter that blocks infrared light or an ultraviolet (UV) cutoff filter that blocks ultraviolet light, but the implementation is not limited to these. Since optical filter 192 is positioned closer to the last lens 106 than to image sensor 190, light loss can be reduced, and an increase in the size of image sensor 190 can be prevented.

[0051] When the optical filter 192 includes an infrared filter, it can block radiant heat emitted from external light from being transferred to the image sensor 190. Furthermore, the optical filter 192 can transmit visible light and reflect infrared light. As another example, a cover glass can also be disposed between the optical filter 192 and the image sensor 190. The cover glass (not shown) can be included between the optical filter 192 and the image sensor 190. The cover glass can protect the image sensor 190. The imaging device module can be an imaging device for capturing RGB images or an imaging device for capturing both RGB and infrared images.

[0052] The optical system 1000 according to the embodiment may include an aperture stop ST. The aperture stop ST can be a light-blocking device that adjusts the amount of light incident on the optical system 1000. For example, the aperture stop ST may be disposed around the sensor-side surface of the third lens 103 or around the object-side surface of the fourth lens 104. The aperture stop ST may be positioned closer to the fourth lens 104 than to the third lens 103. Alternatively, the object-side surface of the fourth lens 104 may perform the function of an aperture stop.

[0053] The optical axis distance SD from the aperture stop ST to the sensor-side surface of the nth lens can be less than the optical axis distance TD from the object-side surface of the first lens 101 to the sensor-side surface of the nth lens. The distance relationship with EFL, ImgH, and TTL can vary depending on the position of the aperture stop ST. At least one or all of the following conditions can be satisfied: and Here, EFL is the effective focal length of the entire optical system, and can be defined as F. The following conditions must be met: The field of view (FOV) of the optical system 1000 can be 100 degrees or less, for example, in the range of 30 degrees to 100 degrees, and for example, in the range of 50 degrees to 80 degrees. The F-number (F#) of the optical system 1000 can be greater than 1 and less than 10, for example, in... Within a certain range, and when the F-number F# is 3 or less, a bright image can be provided. Furthermore, F# can be larger than the entrance pupil diameter EPD. Therefore, the optical system 1000 can have a slim size, control the incident light, and possess improved optical characteristics within the field of view.

[0054] The optical system 1000 according to the embodiment may further include a reflective member (not shown) for changing the path of light. The reflective member may be implemented as a prism that reflects light incident on the first lens group LG1 toward the lens.

[0055] The optical system according to the embodiments will be described in detail below. Figures 1 to 5This is a drawing used to describe an optical system according to a first embodiment. (Refer to...) Figure 1 and Figure 2 In a first embodiment of the present invention, the lens unit 100 may include a first lens 101 to a sixth lens 106. The first lens 101 to the sixth lens 106 may be aligned sequentially along the optical axis OA. Light corresponding to the information of the object may pass through the first lens 101 to the sixth lens 106 and the optical filter 192, and may be incident on the image sensor 190.

[0056] The optical axis distance CG2 between the second lens 102 and the third lens 103 can be the optical axis distance between the first lens group LG1 and the second lens group LG2. Among the first lens 101 to the sixth lens 106, the number of lenses having a meniscus shape convex toward the object side on the optical axis can be two or more. The first lens 101 can have a positive (+) or negative (-) refractive power on the optical axis OA, and preferably has a positive (+) refractive power. The first lens 101 can comprise plastic or glass material. For example, the first lens 101 can be made of glass. Since the first lens 101 is configured as a glass lens, heat-induced degradation of the lens's optical properties can be prevented near the object. On the optical axis OA, the object-side first surface S1 of the first lens 101 can have a convex shape, and the sensor-side second surface S2 can have a concave shape. That is, the first lens 101 can have a meniscus shape convex toward the object side on the optical axis OA. Since the first lens 101 has a meniscus shape convex toward the object side, the amount of incident light can be improved. At least one or both of the first surface S1 and the second surface S2 may be spherical surfaces. Alternatively, the first lens 101 may have a shape in which both surfaces are convex. Alternatively, the first lens 101 may have a shape in which both surfaces are concave.

[0057] The second lens 102 may have a positive (+) or negative (-) refractive power on the optical axis OA. The second lens 102 may have a negative (-) refractive power. The second lens 102 may comprise plastic or glass material. For example, the second lens 102 may be a plastic lens. On the optical axis OA, the object-side third surface S3 of the second lens 102 may have a convex shape, and the sensor-side fourth surface S4 may have a concave shape. That is, the second lens 102 may have a meniscus shape convex toward the object side on the optical axis OA. Alternatively, on the optical axis OA, the third surface S3 may have a convex shape, and the fourth surface S4 may have a convex shape. Alternatively, both the third surface S3 and the fourth surface S4 may have concave shapes. Since the second lens 102, made of plastic material, has a greater center thickness CT1 than the center thickness CT2 of the first lens 101, made of glass material, and has a convex meniscus shape, the increase in the effective length of the third lens 103 can be suppressed. The focal length (in absolute value) of the second lens 102 can be the largest among the lens units 100, and can correct the spherical aberration produced by the first lens 101.

[0058] At least one or both of the third surface S3 and the fourth surface S4 of the second lens 102 can be aspherical surfaces. Figure 3 The configuration is shown in the diagram, where L2 represents the second lens 102, L2S1 represents the third surface, and L2S2 represents the fourth surface. The third surface S3 and the fourth surface S4 of the second lens 102 can be configured to have no critical point from the optical axis to the end of the effective region. A critical point can be a point where the slope of the tangent across the lens surface increases and then decreases, or decreases and then increases. The third surface S3 of the second lens 102 can face the second surface S2 of the first lens 101. That is, the distance between the first lens 101 and the second lens 102, from the center distance to the edge distance, can be 0.5 mm or less. Therefore, the loss of light passing through the first lens 101 and the second lens 102 can be reduced.

[0059] The maximum sagittal value (in absolute terms) of the fourth surface S4 on the sensor side of the second lens 102 can be greater than the center thickness CT2 of the second lens 102, and can be the largest of the absolute sagittal values ​​among the various lens surfaces of the first lens 101 to the sixth lens 106. Here, the sagittal value is the distance from a straight line perpendicular to the optical axis OA at the center of each lens surface in the optical axis direction to that lens surface. When the sagittal value is positive, each lens surface can be located on the sensor side of that straight line, and when the sagittal value is negative, each lens surface can be located on the object side of that straight line.

[0060] The third lens 103 may have a positive (+) or negative (-) refractive power on the optical axis OA, and preferably has a positive (+) refractive power. The third lens 103 may comprise a plastic or glass material. For example, the third lens 103 may be made of glass. On the optical axis OA, the object-side fifth surface S5 of the third lens 103 may have a convex shape, and the sensor-side sixth surface S6 may have a concave shape. That is, the third lens 103 may have a meniscus shape convex toward the object on the optical axis OA. Alternatively, the third lens 103 may have a shape where both surfaces are convex. Alternatively, both the fifth surface S5 and the sixth surface S6 may have concave shapes. Alternatively, the third lens 103 may have a meniscus shape convex toward the sensor side. At least one or both of the fifth surface S5 and the sixth surface S6 of the third lens 103 may be aspherical surfaces. The aspheric coefficients of the fifth surface S5 and the sixth surface S6 are as follows: Figure 3 The settings are shown in the diagram, where L3 represents the third lens 103, L3S1 represents the fifth surface, and L3S2 represents the sixth surface.

[0061] The distance between the second lens 102 and the third lens 103 gradually decreases from the center of the second lens 102 to the edge of the third lens 103. The center distance CG2 between the second lens 102 and the third lens 103 can be greater than the sum of the center thicknesses CT1 and CT2 of the first lens 101 and the second lens 102. The center distance CG2 between the second lens 102 and the third lens 103 can be the largest among the center distances between the lenses. The center distance CG2 between the second lens 102 and the third lens 103 can be greater than the maximum thickness of the lens, such as the maximum center thickness.

[0062] The fourth lens 104 may have a positive (+) or negative (-) refractive power on the optical axis OA. The fourth lens 104 may be the (n-2)th lens and may have a positive (+) refractive power. The fourth lens 104 may comprise plastic or glass material. For example, the fourth lens 104 may be a plastic lens. On the optical axis OA, the object-side seventh surface S7 of the fourth lens 104 may have a convex shape, and the sensor-side eighth surface S8 may have a convex shape. That is, the fourth lens 104 may have a shape where both surfaces are convex on the optical axis OA. Alternatively, the fourth lens 104 may have a meniscus shape convex toward the object side. Alternatively, the fourth lens 104 may have a meniscus shape convex toward the sensor side on the optical axis. Alternatively, the fourth lens 104 may have a shape where both surfaces are concave. At least one or both of the seventh surface S7 and the eighth surface S8 may be aspherical surfaces, and their aspheric coefficient is as follows: Figure 3The configuration is shown in the diagram, where L4 represents the fourth lens 104, L4S1 represents the seventh surface, and L4S2 represents the eighth surface. The fourth lens 104 can have the smallest effective length among the lenses. The maximum effective length of the lens can be greater than twice the minimum effective length, for example, three or four times or more than the minimum effective length. The effective length of the lens can gradually decrease from the first lens 101 to the fourth lens 104, and can gradually increase from the fourth lens 104 to the sixth lens 106. Since the signs of the refractive power of the third lens 103 and the fourth lens 104 are opposite to the signs of the refractive power of the first lens 101 and the second lens 102, the chromatic aberrations produced by the individual lenses can be mutually corrected.

[0063] The fifth lens 105 may have a positive (+) or negative (-) refractive power on the optical axis OA. The fifth lens 105 may be the (n-1)th lens and may have a negative refractive power. The fifth lens 105 may comprise plastic or glass material. For example, the fifth lens 105 may be a plastic lens. On the optical axis OA, the object-side ninth surface S9 of the fifth lens 105 may have a concave shape, and the sensor-side tenth surface S10 may have a concave shape. That is, the fifth lens 105 may have a shape where both surfaces are concave on the optical axis OA. Alternatively, the fifth lens 105 may have a meniscus shape convex toward the sensor side. Alternatively, the fifth lens 105 may have a shape where both surfaces are convex. Alternatively, the fifth lens 105 may have a meniscus shape convex toward the object side on the optical axis OA. At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 105 may be aspherical surfaces, and their aspheric coefficient is as follows: Figure 3 The configuration is shown in the diagram, where L5 represents the fifth lens 105, L5S1 represents the ninth surface, and L5S2 represents the tenth surface. At least one or both of the ninth surface S9 and the tenth surface S10 of the fifth lens 105 can be configured to have no critical points. Furthermore, the distance between the eighth surface S8 of the fourth lens 104 and the ninth surface S9 of the fifth lens 105, from the center to the edge, can be less than 0.1 mm. Because the distance between the fourth lens 104 and the fifth lens 105 is small, the loss of light passing through the fourth lens 104 and the fifth lens 105 can be reduced.

[0064] The sixth lens 106 may have a positive (+) or negative (-) refractive power on the optical axis OA. The sixth lens 106 may be the nth lens and may have a refractive power with a sign opposite to that of the (n-1)th lens, and may, for example, have a positive refractive power. The sixth lens 106 may comprise plastic or glass material. For example, the sixth lens 106 may be a plastic lens. On the optical axis OA, the object-side eleventh surface S11 of the sixth lens 106 may have a convex shape, and the sensor-side twelfth surface S12 may have a convex shape. That is, the sixth lens 106 may have a shape where both surfaces are convex on the optical axis OA. Alternatively, the sixth lens 106 may have a meniscus shape convex toward the object or convex toward the sensor. Alternatively, the sixth lens 106 may have a shape where both surfaces are concave. At least one or both of the eleventh surface S11 and the twelfth surface S12 may be aspherical surfaces, and their aspheric coefficient is as follows: Figure 3 The settings are shown in the diagram, where L6 represents the sixth lens 106, L6S1 represents the eleventh surface, and L6S2 represents the twelfth surface.

[0065] The sixth lens 106 may have a center thickness CT6 greater than the edge thickness. In terms of absolute values ​​of sagittal height, the maximum sagittal height Sag61 of the object-side surface of the sixth lens 106 may be less than the center thickness CT6 of the sixth lens 106, and may be less than the maximum sagittal height Sag21 of the sensor-side surface of the second lens 102. Furthermore, in terms of absolute values ​​of sagittal height, the maximum sagittal height Sag61 of the object-side surface of the sixth lens 106 may be greater than the maximum sagittal height of the sensor-side surface. The fifth lens 105 and the sixth lens 106 can control the path of light refracted towards the image sensor 190 through the fourth lens 104. Therefore, the optical system 1000 according to the embodiment can have improved optical characteristics in the central and peripheral portions of the field of view (FOV).

[0066] Along the optical axis, the radii of curvature of the first surface S1 and the second surface S2 of the first lens 101 can be defined as L1R1 and L1R2, the radii of curvature of the third surface S3 and the fourth surface S4 of the second lens 102 can be defined as L2R1 and L2R2, the radii of curvature of the fifth surface S5 and the sixth surface S6 of the third lens 103 can be defined as L3R1 and L3R2, the radii of curvature of the seventh surface S7 and the eighth surface S8 of the fourth lens 104 can be defined as L4R1 and L4R2, the radii of curvature of the ninth surface S9 and the tenth surface S10 of the fifth lens 105 can be defined as L5R1 and L5R2, and the radii of curvature of the eleventh surface S11 and the twelfth surface S12 of the sixth lens 106 can be defined as L6R1 and L6R2. The radii of curvature can satisfy at least one of the following conditions to improve the aberration characteristics of the optical system.

[0067] Condition 1: Condition 2:

[0068] Condition 3: Condition 4:

[0069] Condition 5:

[0070] Condition 6:

[0071] Condition 7: Condition 8:

[0072] In terms of the absolute value of the radius of curvature of each lens surface, the fourth surface S4 of the second lens 102 can have the smallest value among the lens surfaces, and the tenth surface S10 of the fifth lens 105 can have the largest value among the lens surfaces. In terms of the absolute value of the radius of curvature of each lens (as an average value), the fifth lens 105 can have the largest value among the lenses. By setting the radius of curvature of each lens as described above, good optical performance can be provided at the focal length of each lens.

[0073] The effective lengths of the first lens 101 to the sixth lens 106 can be defined as CA1 to CA8. The effective length CA1 of the first lens 101 can be the maximum effective length in the lens unit 100, and can be 7 mm or greater. The effective length CA4 of the fourth lens 104 can be the minimum effective length in the lens unit 100. The maximum effective length of the lens can be greater than twice the minimum effective length, for example, it can be in the range of three to six times the minimum effective length.

[0074] Along the optical axis, the effective lengths of the first surface S1 and the second surface S2 of the first lens 101 can be defined as CA11 and CA12, the effective lengths of the third surface S3 and the fourth surface S4 of the second lens 102 can be defined as CA21 and CA22, the effective lengths of the fifth surface S5 and the sixth surface S6 of the third lens 103 can be defined as CA31 and CA32, the effective lengths of the seventh surface S7 and the eighth surface S8 of the fourth lens 104 can be defined as CA41 and CA42, the effective lengths of the ninth surface S9 and the tenth surface S10 of the fifth lens 105 can be defined as CA51 and CA52, and the effective lengths of the eleventh surface S11 and the twelfth surface S12 of the sixth lens 106 can be defined as CA61 and CA62. These effective lengths are factors affecting the aberration characteristics of the optical system and can satisfy at least one of the following conditions.

[0075] Condition 1: Condition 2: Condition 3: Condition 3: Condition 4: Condition 5:

[0076] The effective length CA11 of the object-side surface S1 of the first lens 101 can be set to the maximum in the optical system, thereby increasing the amount of incident light. Therefore, the difference between the effective length of the sensor-side surface S12 of the sixth lens 106 and the maximum effective length can be set to 2 mm or greater by the shape of the second lens 102.

[0077] In the first lens 101 to the sixth lens 106, the number of lenses with an effective length smaller than the diagonal length of the image sensor 190 can be three or more. For example, the effective length of the third lens 103 to the sixth lens 106 can be smaller than the diagonal length of the image sensor 190. Among the effective lengths of the respective lens surfaces S1 to S12 of lenses 101 to 106, lens surfaces with an effective length smaller than the effective diagonal length of the image sensor 190 can account for 80% or less of all lens surfaces, for example, in the range of 60% to 80%. For example, the effective length of the fifth surface S5 to the twelfth surface S12 can be smaller than the effective diagonal length of the image sensor 190. Furthermore, the effective length of the fourth surface S3 can be smaller than the effective diagonal length of the image sensor 190.

[0078] The number of lenses having a refractive index greater than 1.6 can be two or more, and the number of lenses having a refractive index less than 1.6 can also be two or more. In the plastic lenses of the lens unit, the fifth lens 105 can have a refractive index of 1.60 or greater, and can refract light incident through the fourth lens 104 towards the entire area of ​​the sixth lens 106. The third lens 103 can have the highest refractive index among the lenses and can reduce light loss caused by the difference between the effective length of the second lens 102 and the effective length of the fourth lens 104. The average refractive index of the first lens 101 to the sixth lens 106 can be 1.60 or greater. In the optical system, the number of lenses having an Abbe number greater than 45 can be greater than the number of lenses having an Abbe number less than 45. The average Abbe number of the first lens 101 to the sixth lens 106 can be 43 or greater. By setting the refractive index and Abbe number of each lens as described above, the influence of chromatic aberration can be controlled.

[0079] When the refractive indices of each lens 101 to 106 are Nd1, Nd2, Nd3, Nd4, Nd5 and Nd6, and the Abbe numbers of each lens 101 to 106 are Vd1, Vd2, Vd3, Vd4, Vd5 and Vd6, at least one of the following conditions can be satisfied.

[0080] Condition 1: Condition 2:

[0081] Condition 3: Condition 4:

[0082] Condition 5: Condition 6:

[0083] Condition 7:

[0084] Based on the refractive index and Abbe number, the optical system 1000 can have improved chromatic aberration control characteristics.

[0085] The center thicknesses of the first lens 101 to the sixth lens 106 can be defined as CT1 to CT6, respectively, and the center distances between the first lens 101 to the sixth lens 106 can be defined as CG1 to CG5, respectively. Furthermore, the edge thicknesses of each lens can be defined as ET1 to ET6. The optical axis distance between the image sensor 190 and the sensor-side surface S12 of the last lens 106 is the back focal length (BFL). Here, the edge thickness of each lens can be the distance between the effective areas of the corresponding lens in the optical axis direction. The optical system can satisfy at least one of the following conditions.

[0086] Condition 1: Condition 2:

[0087] Condition 3: Condition 4:

[0088] Condition 5: Condition 6:

[0089] Condition 7: Condition 8:

[0090] Condition 9:

[0091] The center thickness CT6 of the sixth lens 106 can be the largest among the center thicknesses of the lenses. The center thickness CT5 of the fifth lens 105 can be the smallest among the center thicknesses of the lenses, or it can be 0.5 mm or less. The center distance CG2 between the second lens 102 and the third lens 103 can be the largest among the center distances between adjacent lenses. The center distance CG4 between the fourth lens 104 and the fifth lens 105 can be the smallest among the center distances between lenses. The ratio of the center thicknesses of the glass lenses can satisfy: And preferably, it can satisfy: .

[0092] In lenses 101 to 106, the maximum center thickness can be eight times or less than the minimum center thickness, for example, it can be in the range of two to eight times the minimum center thickness. The number of lenses with a center thickness of 0.8 mm or less can be less than the number of lenses with a center thickness greater than 0.8 mm. The sum of the center thicknesses of the first lens 101 to the sixth lens 106 can be greater than the sum of the center distances between the first lens 101 to the sixth lens 106. The difference between the sum of the center thicknesses of the first lens 101 to the sixth lens 106 and the sum of the center distances between the first lens 101 to the sixth lens 106 can be 3 mm or less. Therefore, the optical system 1000 can control the incident light and can have improved aberration characteristics and resolution.

[0093] When the focal lengths of the lenses 101 to 106 are defined as F1, F2, F3, F4, F5, and F6, the following conditions can be satisfied in terms of absolute values: Furthermore, the focal length (in absolute value) of a lens made of glass can satisfy the following conditions: Furthermore, the average absolute value of the focal lengths of the second lens 102 to the sixth lens 106 arranged sequentially can be 7 mm or less, for example, in the range of 2 mm to 7 mm or in the range of 2 mm to 5 mm. When the focal length is described in absolute value, the focal length F1 of the first lens 101 can be the largest among the lenses, and the focal length F5 of the fifth lens 105 can be the smallest. The maximum focal length can be ten times the minimum focal length or less. The total focal length of the optical system 1000 can be less than the absolute value of the focal length of the first lens 101, and for example, less than the focal length F6 of the sixth lens 106.

[0094] Such an optical system can be applied to camera module systems for vehicles, and can be applied to camera module systems for forward-looking monocular or multi-view cameras, side-view cameras, CMS camera monitoring systems, surround-view cameras, rear-view cameras, OMS occupant monitoring systems, or DMS driver monitoring systems. For example, this invention can be applied to camera module systems for OMS occupant monitoring systems or DMS driver monitoring systems.

[0095] Figure 4 It is shown Figure 1 The diffraction MTF modulation transfer function of the optical system is plotted, and the modulation degree according to the spatial frequency is shown. That is, Figure 4 The diffraction MTF at room temperature is shown, and the graph was obtained by measuring the modulation based on the defocus position in the OMS occupant monitoring system-RGB sensor.

[0096] Figure 5 This is a graph showing the aberration characteristics of the optical system according to the first embodiment of the present invention at room temperature. (Refer to...) Figure 5 In the aberration diagram of the optical system, longitudinal spherical aberration, astigmatism, and distortion are measured from left to right. The X-axis can represent the focal length (mm) and distortion (%), and the Y-axis can represent the image height. Furthermore, the spherical aberration diagram is for light in the wavelength bands of approximately 435 nm, approximately 481 nm, approximately 546 nm, approximately 587 nm, approximately 656 nm, approximately 920 nm, approximately 940 nm, and approximately 960 nm, and the astigmatism and distortion aberration diagrams are for light in the 546 nm wavelength band. The optical system 1000 according to the embodiment can have improved resolution and can have good optical performance not only in the central portion of the FOV but also in the peripheral portion. As confirmed in the embodiment, the lens system according to the embodiment of the invention can satisfactorily correct spherical aberration, astigmatism, distortion aberration, chromatic aberration, and coma using a configuration of seven or fewer lenses, such as six lenses.

[0097] Figures 6 to 9 It shows the use Figure 1 The accompanying drawings show the optical system and camera module according to the second embodiment. In describing the second embodiment, the following are used... Figure 1 The optical system, and the configuration that is the same as that of the first embodiment, may include the configuration and description of the first embodiment, and redundant descriptions of the same configuration and features will be omitted.

[0098] Reference Figure 1 , Figure 6 and Figure 7In the lens unit of the second embodiment, the shapes of the first surface S1 to the twelfth surface S12 of the first lens 101 to the sixth lens 106, which are concave or convex along the optical axis, and the symbols for the optical power of each lens can refer to the first embodiment. For example, the first lens 101 to the third lens 103 may have a meniscus shape convex toward the object, the fourth lens 104 may have two convex surfaces, the fifth lens 105 may have two concave surfaces, and the sixth lens 106 may have two convex surfaces. The first lens 101, the second lens 102, and the fifth lens 105 may have negative optical power, and the third lens 103, the fourth lens 104, and the sixth lens 106 may have positive optical power.

[0099] The first lens 101 and the second lens 102 can constitute a first lens group LG1, and the third lens 103 to the sixth lens 106 can constitute a second lens group LG2. An aperture stop ST can be disposed between the first lens group LG1 and the second lens group LG2. The first lens 101 and the third lens 103 can be made of glass, and the second lens 102, the fourth lens 104, the fifth lens 105, and the sixth lens 106 can be made of plastic.

[0100] Among the first lens 101 to the sixth lens 106, the third lens 103 can have the largest refractive index, the first lens 101 can have the largest effective length, and the absolute value of the focal length of the first lens 101 can be the largest. Among the first surface S1 to the twelfth surface S12 of the lens, the first surface S1 can have the largest effective length, and the seventh surface S7 can have the smallest effective length. Among the effective lengths of the lens surfaces S1 to S12, the lens surfaces with an effective length less than the effective diagonal length of the image sensor 190 can account for 80% or less of all the lens surfaces, for example, in the range of 60% to 80%. For example, the effective lengths of the fifth surface S5 to the twelfth surface S12 can be less than the effective diagonal length of the image sensor 190. Furthermore, the effective length of the fourth surface S3 can be less than the effective diagonal length of the image sensor 190.

[0101] Among the first lens 101 to the sixth lens 106, the center thickness CT6 of the sixth lens 106 can be the largest, the center thickness CT5 of the fifth lens 105 can be the smallest, the edge thickness ET2 of the second lens 102 can be the largest, and the edge thickness ET4 of the fourth lens 104 can be the smallest. Among the first surface S1 to the twelfth surface S12 of the lens, the absolute value of the radius of curvature of the tenth surface S10 of the fifth lens 105 on the optical axis can be the largest. Regarding the optical axis distance between adjacent lenses, the optical axis distance CG2 between the second lens 102 and the third lens 103 can be the largest, and the optical axis distance CG4 between the fourth lens 104 and the fifth lens 105 can be the smallest.

[0102] The first surface S1 to the twelfth surface S12 can have a shape without a critical point from the optical axis OA to the end of the effective region. The third and fourth surfaces S3 and S4 of the second lens 102, the seventh and eighth surfaces S7 and S8 of the fourth lens 104, the ninth and tenth surfaces S10 of the fifth lens 105, and the eleventh and twelfth surfaces S11 and S12 of the sixth lens 106 can have aspherical shapes on the optical axis, and can have, for example... Figure 7 The aspherical coefficients shown are as follows.

[0103] An aperture stop ST can be positioned around the region between the third lens 103 and the fourth lens 104. The aperture stop ST can be positioned closer to the seventh surface S7 than to the sixth surface S6. Therefore, an increase in the effective length of the fourth lens 104 can be prevented. An optical filter 192 can be positioned between the sixth lens 106 and the image sensor 190. The optical filter 192 can be positioned closer to the sixth lens 106 than to the image sensor 190.

[0104] The sagittal value Sag22 of the fourth surface S4 of the second lens 102 can be the largest among the absolute values ​​of the sagittal values ​​of the first surface S1 to the twelfth surface S12. The sagittal value Sag61 of the eleventh surface S11 of the sixth lens 106 can be greater than the absolute value of the sagittal value of the twelfth surface S12. Therefore, the sixth lens 106, which has the maximum thickness, can refract light incident through the eleventh surface S11 towards the entire area of ​​the image sensor 190.

[0105] The FOV, TTL, TD, SD, BFL, etc. of the optical system 1000 can refer to the first embodiment. The formulas and conditions for optical characteristics such as refractive index, Abbe number, effective length, focal length, and radius of curvature of the first lens 101 to the sixth lens 106 can include the contents disclosed in the first embodiment.

[0106] Figure 8 It is shown Figure 6The diffraction MTF curve of the optical system is plotted, and the modulation index according to the spatial frequency is shown. That is, Figure 8 The diffraction MTF at room temperature is shown, and the graph was obtained by measuring the modulation based on the defocus position in an OMS-RGB sensor. Figure 9 This is a graph showing the aberration characteristics of the optical system according to the second embodiment of the present invention at room temperature. (Refer to...) Figure 9 In the aberration graph of the optical system, spherical aberration, astigmatism, and distortion aberration are measured from left to right. The X-axis can represent the focal length (mm) and distortion (%), and the Y-axis can represent the image height. Furthermore, the spherical aberration graph is for light in the wavelength bands of approximately 435 nm, approximately 481 nm, approximately 546 nm, approximately 587 nm, approximately 656 nm, approximately 920 nm, approximately 940 nm, and approximately 960 nm, and the astigmatism and distortion aberration graphs are for light in the 546 nm wavelength band. The optical system 1000 according to the embodiment can have improved resolution and can have good optical performance not only in the central portion of the field of view (FOV) but also in the peripheral portion. As confirmed in the embodiment, the lens system according to the embodiment of the invention can satisfactorily correct spherical aberration, astigmatism, distortion aberration, chromatic aberration, and coma using a configuration of seven or fewer lenses, such as six lenses.

[0107] Figures 10 to 13 It shows the use Figure 1 The accompanying drawings show the optical system and camera module according to the third embodiment. In describing the third embodiment, the following are used... Figure 1 The optical system, and the configuration that is the same as that of the first embodiment, may include the configuration and description of the first embodiment, and redundant descriptions of the same configuration and features will be omitted.

[0108] Reference Figure 1 , Figure 10 and Figure 11 In the lens unit of the third embodiment, the shapes of the first surface S1 to the twelfth surface S12 of the first lens 101 to the sixth lens 106, which are concave or convex along the optical axis, and the symbols for the optical power of each lens can be referred to in the third embodiment. For example, the first lens 101 to the third lens 103 may have a meniscus shape convex toward the object, the fourth lens 104 may have two convex surfaces, the fifth lens 105 may have two concave surfaces, and the sixth lens 106 may have two convex surfaces. The first lens 101, the second lens 102, and the fifth lens 105 may have negative optical power, and the third lens 103, the fourth lens 104, and the sixth lens 106 may have positive optical power.

[0109] The first lens 101 and the second lens 102 can constitute a first lens group LG1, and the third lens 103 to the sixth lens 106 can constitute a second lens group LG2. An aperture stop ST can be disposed between the first lens group LG1 and the second lens group LG2. The first lens 101 and the third lens 103 can be made of glass, and the second lens 102, the fourth lens 104, the fifth lens 105, and the sixth lens 106 can be made of plastic.

[0110] Among the first lens 101 to the sixth lens 106, the third lens 103 can have the largest refractive index, the first lens 101 can have the largest effective length, and the absolute value of the focal length of the first lens 101 can be the largest. Among the first surface S1 to the twelfth surface S12 of the lens, the first surface S1 can have the largest effective length, and the seventh surface S7 can have the smallest effective length. Among the effective lengths of the lens surfaces S1 to S12, the lens surfaces with an effective length less than the effective diagonal length of the image sensor 190 can account for 80% or less of all the lens surfaces, for example, in the range of 60% to 80%. For example, the effective lengths of the fifth surface S5 to the twelfth surface S12 can be less than the effective diagonal length of the image sensor 190. Furthermore, the effective length of the fourth surface S3 can be less than the effective diagonal length of the image sensor 190.

[0111] Among the first lens 101 to the sixth lens 106, the center thickness CT6 of the sixth lens 106 can be the largest, the center thickness CT5 of the fifth lens 105 can be the smallest, the edge thickness ET2 of the second lens 102 can be the largest, and the edge thickness ET4 of the fourth lens 104 can be the smallest. Among the first surface S1 to the twelfth surface S12 of the lens, the absolute value of the radius of curvature of the tenth surface S10 of the fifth lens 105 on the optical axis can be the largest. Regarding the optical axis distance between adjacent lenses, the optical axis distance CG2 between the second lens 102 and the third lens 103 can be the largest, and the optical axis distance CG4 between the fourth lens 104 and the fifth lens 105 can be the smallest. The first surface S1 to the twelfth surface S12 can have a shape without a critical point from the optical axis OA to the end of the effective region. The third and fourth surfaces S3 and S4 of the second lens 102, the seventh and eighth surfaces S7 and S8 of the fourth lens 104, the ninth and tenth surfaces S10 of the fifth lens 105, and the eleventh and twelfth surfaces S11 and S12 of the sixth lens 106 may have aspherical shapes on the optical axis, and may have, for example, the following... Figure 11 The aspherical coefficients shown are as follows.

[0112] The sagittal value Sag22 of the fourth surface S4 of the second lens 102 can be the largest among the absolute values ​​of the sagittal values ​​of the first surface S1 to the twelfth surface S12. The sagittal value Sag61 of the eleventh surface S11 of the sixth lens 106 can be greater than the absolute value of the sagittal value of the twelfth surface S12. Therefore, the sixth lens 106, which has the maximum thickness, can refract light incident through the eleventh surface S11 towards the entire area of ​​the image sensor 190.

[0113] An aperture stop ST can be positioned around the region between the third lens 103 and the fourth lens 104. The aperture stop ST can be positioned closer to the seventh surface S7 than to the sixth surface S6. Therefore, an increase in the effective length of the fourth lens 104 can be prevented. An optical filter 192 can be positioned between the sixth lens 106 and the image sensor 190. The optical filter 192 can be positioned closer to the sixth lens 106 than to the image sensor 190.

[0114] The FOV, TTL, TD, SD, BFL, etc. of the optical system 1000 can refer to the first embodiment. The formulas and conditions for optical characteristics such as refractive index, Abbe number, effective length, focal length, and radius of curvature of the first lens 101 to the sixth lens 106 can include the contents disclosed in the first embodiment.

[0115] Figure 12 It is shown Figure 10 The diffraction MTF curve of the optical system is plotted, and the modulation index according to the spatial frequency is shown. That is, Figure 12 The diffraction MTF at room temperature is shown, and the graph was obtained by measuring the modulation based on the defocus position in an OMS-RGB sensor. Figure 13 This is a graph showing the aberration characteristics of the optical system according to the third embodiment of the present invention at room temperature. (Refer to...) Figure 13In the aberration graph of the optical system, spherical aberration, astigmatism, and distortion aberration are measured from left to right. The X-axis can represent the focal length (mm) and distortion (%), and the Y-axis can represent the image height. Furthermore, the spherical aberration graph is for light in the wavelength bands of approximately 435 nm, approximately 481 nm, approximately 546 nm, approximately 587 nm, approximately 656 nm, approximately 920 nm, approximately 940 nm, and approximately 960 nm, and the astigmatism and distortion aberration graphs are for light in the 546 nm wavelength band. The optical system 1000 according to the embodiment can have improved resolution and can have good optical performance not only in the central portion of the field of view (FOV) but also in the peripheral portion. As confirmed in the embodiment, the lens system according to the embodiment of the invention can satisfactorily correct spherical aberration, astigmatism, distortion aberration, chromatic aberration, and coma using a configuration of seven or fewer lenses, such as six lenses.

[0116] The optical systems disclosed above according to the first to third embodiments can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance not only in the central part of the field of view but also in the peripheral part. Figure 14 As shown, in the optical systems according to the first to third embodiments, Figure 14 It is a graph showing the distortion percentage from the image height at the center of the image sensor (i.e., from 0.0 field of view to 1.0 field of view), and it can be seen that the distortion is close to 0 up to 0.5 field of view, and is generally in the range of 0% to -40%.

[0117] The optical system 1000 disclosed above according to embodiments can satisfy at least one, two, or more of the formulas described below. Therefore, the optical system 1000 according to embodiments can have improved optical characteristics. For example, when the optical system 1000 satisfies these formulas, the optical system 1000 can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance in both the central and peripheral portions of the field of view (FOV). The optical system 1000 can have improved resolution and can have a thinner and more compact structure. In the following, the units for values ​​such as thickness, distance, effective length, radius of curvature, and focal length of the first lens 101 to the sixth lens 106 are mm.

[0118] [Formula 1]

[0119] When the center thickness CT1 of the first lens 101 and the center thickness CT2 of the second lens 102 satisfy Equation 1, the optical system 1000 can improve aberration characteristics. Furthermore, by allowing the center thickness CT2 of the plastic second lens 102 to be greater than twice the center thickness CT1 of the first lens 101 made of glass material, aberration characteristics can be improved. Preferably, Equation 1 can satisfy: .

[0120] [Equation 2]

[0121] When the center thickness CT2 and edge thickness ET2 of the second lens 102 satisfy Equation 2, the optical system 1000 can have improved chromatic aberration control characteristics. Preferably, Equation 2 can satisfy: The edge thickness ET2 of the second lens 102 can be the largest among the edge thicknesses of the lenses.

[0122] [Formula 3]

[0123] In Equation 3, by making the center thickness CT6 of the sixth lens greater than the sum of the center thicknesses of the first lens and the second lens, light loss in the first lens 101 made of glass and the second lens 102 made of plastic can be reduced, and light can be refracted through the sixth lens 106 with the maximum thickness toward the entire area of ​​the image sensor 190.

[0124] [Formula 4]

[0125] When the center thicknesses of the fifth lens 105 and the sixth lens 106 satisfy Equation 4, the optical system 1000 can have improved chromatic aberration control characteristics. Equation 4 can satisfy: 6.5.

[0126] [Formula 5]

[0127] When the center thicknesses of the first lens 101 and the sixth lens 106 satisfy Equation 5, the optical system 1000 can have improved chromatic aberration control characteristics. Equation 5 can satisfy... 5.

[0128] [Formula 6]

[0129] When the optical axis distance CG2 between the second lens 102 and the third lens 103 and the center thickness CT6 of the sixth lens 106 satisfy Equation 6, the increase in the effective length of the second lens group LG2 and the shape of the second lens 102 can be suppressed. Equation 6 can satisfy... .

[0130] [Formula 7]

[0131] When the refractive indices Nd1 and Nd3 of the first lens 101 and the third lens 103, both made of glass, at the d-line satisfy Equation 7, the light path from the first lens 101 to the third lens 103 can be adjusted, and the increase in TTL can be suppressed. Preferably, the refractive index of the third lens 103 can satisfy... .

[0132] [Formula 8]

[0133] When the optical axis distance CG1 between the first lens 101 and the second lens 102, and the optical axis distance CG2 between the second lens 102 and the third lens 103, satisfies Equation 8, the optical axis distance of the first lens group LG1 can be reduced. Preferably, Equation 8 can satisfy... .

[0134] [Formula 9]

[0135] When the center thickness CT4 of the fourth lens 104 and the optical axis distance CG4 between the fourth and fifth lenses satisfy Equation 9, the increase in the effective length of the fifth lens can be suppressed, and the impact on TTL can be reduced. Equation 9 can satisfy: .

[0136] [Formula 10]

[0137] When the optical axis distance CG5 between the fifth and sixth lenses and the center thickness of the fifth lens satisfy Equation 10, the optical path traveling through the fifth lens 105 and the sixth lens 106 can be adjusted, thereby providing good optical performance in the central and peripheral portions of the field of view (FOV). Furthermore, distortion in the optical system 1000 can be reduced, thus providing improved optical performance. Preferably, Equation 10 can satisfy: .

[0138] [Equation 11]

[0139] When the center thickness CT6 of the sixth lens and the optical axis distance CG5 between the fifth and sixth lenses satisfy Equation 11, the optical system 1000 can improve aberration characteristics and control the reduction of the size of the optical system 1000, such as the reduction of the total TTL track length. Preferably, Equation 11 can satisfy... .

[0140] [Equation 12]

[0141] When the optical axis distances between the fourth, fifth, and sixth lenses satisfy Equation 12, the optical system 1000 can have improved aberration characteristics. Furthermore, the optical system 1000 can exhibit good optical performance at a predetermined field of view and can control the total TTL track length. Preferably, Equation 12 can satisfy... .

[0142] [Equation 13]

[0143] When the optical axis distance CG1 between the first lens 101 and the second lens 102 and the optical axis distance CG4 between the fourth lens 104 and the fifth lens 105 satisfy Equation 13, the optical system 1000 can reduce the optical axis distance of the second lens group LG2. Preferably, Equation 13 can satisfy... .

[0144] [Formula 14]

[0145] When the radius of curvature L5R2 of the tenth surface S10 of the fifth lens 105 on the optical axis and the radius of curvature L6R1 of the eleventh surface S11 of the sixth lens 106 on the optical axis satisfy Equation 14, the effective length of the sixth lens 106 can be set to be greater than the effective length of the fifth lens 105, and the aberration characteristics of the optical system 1000 can be improved. Preferably, Equation 14 can satisfy... .

[0146] [Formula 15]

[0147] When the radius of curvature L1R1 of the object-side surface of the first lens and the radius of curvature L2R1 of the object-side surface of the second lens satisfy Equation 15, the degradation of the characteristics of the first lens due to the glass material can be prevented, and the amount of incident light can be increased. Preferably, it can satisfy... .

[0148] [Formula 16]

[0149] When the effective length CA11 of the first surface S1 of the first lens 101 and the effective length CA22 of the fourth surface S4 of the second lens 102 satisfy Equation 16, the optical system 1000 can control the incident light, maintain optical performance, and has improved aberration control characteristics. Preferably, Equation 16 can satisfy... The effective length CA11 of the first surface S1 of the first lens 101 can be the largest among the effective lengths of the lens surface.

[0150] [Equation 17]

[0151] When the effective length CA31 of the fifth surface S5 of the third lens 103 and the effective length CA52 of the tenth surface S10 of the fifth lens 105 satisfy Equation 17, the optical system 1000 can control the path of light incident on the second lens group LG2 and improve aberration characteristics. Preferably, Equation 17 can satisfy... .

[0152] [Formula 18]

[0153] When the effective length CA22 of the fourth surface S4 of the second lens 102 and the effective length CA31 of the fifth surface S5 of the third lens 103 satisfy Equation 18, the difference in effective length between the first lens group LG1 and the second lens group LG2 can be reduced, and light loss can be suppressed. Furthermore, the optical system 1000 can improve chromatic aberration and control vignetting to achieve optimal optical performance. Preferably, Equation 18 can satisfy... .

[0154] [Formula 19]

[0155] When the effective length CA42 of the eighth surface S8 of the fourth lens 104 and the effective length CA52 of the tenth surface S10 of the fifth lens 105 satisfy Equation 19, a light path traveling toward the second lens group LG2 can be configured. Furthermore, the optical system 1000 can improve chromatic aberration. Preferably, Equation 19 can satisfy... .

[0156] [Formula 20]

[0157] When the effective length CA62 of the twelfth surface S12 of the sixth lens 106 and the effective length CA11 of the first surface S1 of the first lens 101 satisfy Equation 20, the effective length and optical path between the incident-side lens and the last lens can be set. Therefore, the size and field of view of the optical system 1000 can be set. Preferably, Equation 20 can satisfy... .

[0158] [Equation 21]

[0159] When the product of the effective length and center thickness of the first lens 101 in Equation 21 is greater than the product of the effective length and center thickness of the sixth lens 106, the optical system 1000 can increase the amount of incident light while maintaining optical performance. Preferably, it can satisfy... .

[0160] [Equation 22]

[0161] In Equation 22, It is the average of the effective lengths of the first lens 101 and the second lens 102. When Equation 22 is satisfied, the effective lengths of the second and third lenses can be controlled, and the TTL can be reduced. Equation 22 can satisfy... .

[0162] [Equation 23]

[0163] In Equation 23, This is the average of the effective lengths of the fourth lens 104 and the fifth lens 105. When the effective lengths of the first and second lenses (which are greater than the effective lengths of the other lenses) and the fourth and fifth lenses (which are less than the effective lengths of the other lenses) satisfy Equation 23, the light travel path can be adjusted. Equation 23 can satisfy... .

[0164] [Equation 24]

[0165] The effective lengths of the third, fourth, and fifth lenses are indicated, and the effective lengths of the third, fourth, and fifth lenses can be less than the effective lengths of the first, second, and sixth lenses. When Equation 24 is satisfied, light incident through the first lens 101 and the second lens 102 can be refracted toward the effective areas of the third lens 103, the fourth lens 104, and the fifth lens 105, and then guided toward the entire area of ​​the sixth lens 106.

[0166] [Equation 25]

[0167] When the center thickness CT6 of the sixth lens and the optical axis distance BFL between the sixth lens and the image sensor 190 satisfy Equation 25, the optical path can be adjusted according to the center thickness CT6 of the sixth lens, and the mounting space for the optical filter 190 can be ensured. Preferably, it can satisfy... .

[0168] [Equation 26]

[0169] When the radius of curvature of the sensor-side surface of the fourth lens and the radius of curvature of the object-side surface of the fifth lens satisfy Equation 26, the optical system 1000 can adjust the refractive power of the fourth and fifth lenses and suppress the increase in the effective length of the sixth lens 106. Preferably, Equation 26 can satisfy... .

[0170] [Equation 27]

[0171] When the radius of curvature L5R2 of the tenth surface S10 of the fifth lens and the center thickness CT5 of the fifth lens satisfy Equation 27, the optical system 1000 can control the refractive power of the fifth lens and improve the optical performance of the light incident on the second lens group LG2. Preferably, Equation 27 can satisfy... And it can meet the conditions .

[0172] [Equation 28]

[0173] When the radius of curvature L4R1 of the seventh surface S7 of the fourth lens and the radius of curvature L6R1 of the eleventh surface S11 of the sixth lens 106 satisfy Equation 28, the shape and refractive power of the fourth and sixth lenses can be controlled to improve optical performance, and the optical performance of the second lens group LG2 can also be improved. Preferably, Equation 28 can satisfy... Preferably, the conditions can be met. and .

[0174] [Equation 29]

[0175] Equation 29 can be used to set the radii of curvature L1R1 and L1R2 of the first surface S1 and the second surface S2 on the object side of the first lens, and when Equation 29 is satisfied, the lens size and resolution can be set. Preferably, Equation 29 can satisfy... Preferably, it can satisfy... and .

[0176] [Formula 30]

[0177] Equation 30 can be used to set the radii of curvature L2R1 and L2R2 of the object-side third surface S3 and fourth surface S4 of the second lens 102, and when Equation 30 is satisfied, the resolution of the second lens can be determined. Preferably, Equation 30 can satisfy... Preferably, it can satisfy... and .

[0178] [Equation 31]

[0179] In Equation 31, the maximum center thickness CT_Max and the maximum optical axis distance CG_Max of the lens can be set. When Equation 31 is satisfied, the optical system 1000 can have good optical performance at a predetermined field of view and focal length, and the size of the optical system 1000 can be reduced, for example, the total TTL track length can be reduced. Preferably, Equation 31 can satisfy... .

[0180] [Equation 32]

[0181] In Equation 32, This represents the sum of the center thicknesses (mm) of multiple lenses, and This represents the sum of the distances (mm) between any two adjacent lenses on the optical axis OA among a plurality of lenses. When the optical system 1000 according to the embodiment satisfies Equation 32, the optical system 1000 can have good optical performance at a predetermined field of view and focal length, and the size of the optical system 1000 can be reduced, for example, the total TTL track length can be reduced. Preferably, Equation 32 can satisfy... .

[0182] [Equation 33]

[0183] In Equation 33, This represents the sum of the refractive indices of the multiple lenses at the d-line. When the optical system 1000 according to the embodiment satisfies Equation 33, the TTL of the optical system 1000 can be controlled, and improved resolution can be provided. Here, the average refractive index of the first to sixth lenses can be 1.50 or greater. Preferably, Equation 33 can satisfy... And it can meet the conditions , where n is the total number of lenses.

[0184] [Equation 34]

[0185] In Equation 34, This represents the sum of the Abbe numbers of multiple lenses. When the optical system 1000 according to the embodiment satisfies Equation 34, the optical system 1000 can have improved aberration characteristics and resolution. Preferably, Equation 34 can satisfy... Preferably, the conditions can be met. .

[0186] [Formula 35]

[0187] When the optical axis distance CG2 between the second and third lenses and the effective length CA31 of the object-side surface of the third lens 103 satisfy Equation 35, the radius of curvature of the sensor-side surface of the second lens can be controlled. Preferably, it can satisfy... .

[0188] [Formula 36]

[0189] In Equation 36, This represents the maximum value of the ratio of the center thickness to the edge thickness of each lens, and the shape of the third or sixth lens can be set. Preferably, it can satisfy... .

[0190] [Formula 37]

[0191] When Equation 37 satisfies the effective length CA11 of the first surface S1 of the first lens and the minimum effective length CA_Min of the lens surface, the amount of light incident through the first lens 101 can be controlled, and a thin optical system can be provided while maintaining optical performance. Preferably, Equation 37 can satisfy... .

[0192] [Formula 38]

[0193] In Equation 38, the minimum effective length CA_min of the object-side surface and sensor-side surface of the multiple lenses, as well as half the diagonal length of the image sensor, can be set. When the optical system 1000 according to the embodiment satisfies Equation 38, a thin and compact optical system can be provided while maintaining optical performance. Preferably, Equation 38 can satisfy... .

[0194] [Formula 39]

[0195] In Equation 39, the maximum effective length CA_Max and the total effective focal length on the object-side and sensor-side surfaces of multiple lenses can be set, and when Equation 39 is satisfied, a thin and compact optical system can be provided. Preferably, Equation 39 can satisfy... .

[0196] [Formula 40]

[0197] In Equation 40, the ratio between the center thickness of the glass lens and the effective diameter of the object-side surface can be set. Therefore, degradation of optical performance in the imaging device module due to heat can be prevented. Preferably, it can satisfy... .

[0198] [Formula 41]

[0199] In Equation 41, the maximum effective length CA_Max of the object-side surface and sensor-side surface of multiple lenses, as well as the diagonal length of the image sensor 190, can be set. Furthermore, when Equation 41 is satisfied, the optical system 1000 can exhibit good optical performance in both the central and peripheral portions of the field of view (FOV), and can provide a thin and compact optical system. Preferably, Equation 41 can satisfy... .

[0200] [Equation 42]

[0201] In Equation 42, TD is the maximum optical axis distance (mm) from the object-side surface of the first lens to the sensor-side surface of the last lens. For example, TD is the distance along the optical axis OA from the first surface S1 of the first lens 101 to the twelfth surface S12 of the sixth lens 106. When the optical system 1000 according to the embodiment satisfies Equation 42, a thin and compact optical system can be provided. Preferably, Equation 42 can satisfy... .

[0202] [Formula 43]

[0203] In Equation 43, the total effective focal length F of the optical system 1000 and the radius of curvature L5R2 of the tenth surface S10 of the fifth lens 105 can be set. Furthermore, when Equation 43 is satisfied, the size of the optical system 1000 can be reduced, for example, the total TTL track length can be reduced. Preferably, Equation 43 can satisfy... .

[0204] [Formula 44]

[0205] In Equation 44, the radius of curvature L1R1 of the first surface S1 of the first lens and the total effective focal length F can be set. Furthermore, when Equation 44 is satisfied, the size of the optical system 1000 can be reduced, for example, the total TTL track length can be reduced. Preferably, Equation 44 can satisfy... .

[0206] [Formula 45]

[0207] In Equation 45, the incident pupil diameter EPD of the optical system 1000 and the radius of curvature of the sensor-side surface of the sixth lens can be set. When the optical system 1000 satisfies Equation 45, the optical system 1000 can control the overall brightness and has good optical performance in the center and peripheral parts of the field of view (FOV). Preferably, Equation 45 can satisfy... .

[0208] [Formula 46]

[0209] Equation 46 represents the relationship between the incident pupil of the optical system and the radius of curvature of the first surface S1 of the first lens, and can control the incident light. Preferably, Equation 46 can satisfy... .

[0210] [Formula 47]

[0211] In Equation 47, the focal lengths F1 and F2 of the first and second lenses can be set. Therefore, by adjusting the refractive power applied to the incident light by the first and second lenses, the resolution can be improved, and the TTL can be controlled. Preferably, Equation 47 can satisfy... And it can meet the conditions and .

[0212] [Formula 48]

[0213] In Equation 48, by setting the combined focal length F12 of the first lens and the second lens and the total focal length F, the optical system 1000 can improve resolution by adjusting the refractive force applied to the incident light, and can control the total TTL trajectory length of the optical system 1000. Preferably, Equation 48 can satisfy... The combined focal length F12 of the first and second lenses is the focal length of the first lens group LG1, and and .

[0214] [Formula 49]

[0215] In Equation 49, the combined focal length F12 of the first and second lenses and the combined focal length F36 of the third to sixth lenses can be set. When Equation 49 is satisfied, resolution can be improved by controlling the refractive power of the first lens group and the refractive power of the second lens group, and the optical system can be provided in a thin and compact size. Furthermore, when Equation 49 is satisfied, the optical system 1000 can improve aberration characteristics such as chromatic aberration and distortion aberration. Preferably, Equation 49 can satisfy... Here, the conditions are met. .

[0216] [Formula 50]

[0217] In Equation 50, the focal length F1 of the first lens 101 and the combined focal length F12 of the first and second lenses can be set to improve the resolution of the first lens group. Equation 50 can satisfy... .

[0218] [Equation 51]

[0219] In Equation 51, the focal length F1 of the first lens and the combined focal length F36 of the third to sixth lenses can be set to adjust the resolution of the second lens group. Preferably, Equation 51 can satisfy... .

[0220] [Equation 52]

[0221] In Equation 52, the average refractive power of the third to sixth lenses can be set, thereby adjusting the size of the optical system and the resolution of the second lens group. The following conditions can be satisfied. .

[0222] [Formula 53]

[0223] In Equation 53, the focal length F1 of the first lens and the focal length F4 of the fourth lens can be set to control the refractive power of the light incident on the first and second lens groups, and to adjust the size and resolution of the optical system. Preferably, Equation 53 can satisfy... ,and .

[0224] [Formula 54]

[0225] In Equation 54, the total TTL track length refers to the distance along the optical axis OA from the center of the first surface S1 of the first lens to the image surface of the image sensor 190. Preferably, Equation 54 can satisfy... .

[0226] [Formula 55]

[0227] Equation 55 can be achieved by adjusting the diagonal size of the image sensor 190. The setting is greater than 4 mm to provide an optical system with high resolution. Preferably, Equation 55 can satisfy... or .

[0228] [Formula 56]

[0229] Equation 56 sets the back focal length of the BFL to less than 2.5 mm, thereby ensuring mounting space for the optical filter 192, improving component assemblability and coupling reliability through the distance between the image sensor 190 and the last lens. Preferably, Equation 56 can satisfy... .

[0230] [Formula 57]

[0231] In Equation 57, the total focal length F can be set according to the optical system, and preferably it can satisfy... or .

[0232] [Formula 58] Spend

[0233] In Equation 58, FOV refers to the field of view of the optical system 1000, and can provide an optical system with a field of view of less than 120 degrees. FOV can be 30 degrees or greater, for example, in the range of 30 to 100 degrees.

[0234] [Formula 59]

[0235] In Equation 59, by setting the maximum effective length CA_Max and TTL on the object-side and sensor-side surfaces of multiple lenses, a thin and compact optical system can be provided. Preferably, Equation 59 can satisfy... .

[0236] [Formula 60]

[0237] Equation 60 can be used to set the total optical axis length TTL of the optical system and the diagonal length ImgH of the image sensor 190 from the optical axis. When the optical system 1000 according to the embodiment satisfies Equation 60, the optical system 1000 can achieve high image quality and have a slim structure. Preferably, Equation 60 can satisfy... .

[0238] [Formula 61]

[0239] Equation 61 can set the optical axis distance between the image sensor 190 and the last lens, as well as the diagonal length of the image sensor 190 from the optical axis. When the optical system 1000 according to the embodiment satisfies Equation 61, the optical system 1000 can ensure the back focal length of the BFL and minimize the distance between the last lens and the image sensor 190, thereby having good optical characteristics in the center and peripheral portions of the FOV. Preferably, Equation 61 can satisfy... .

[0240] [Formula 62]

[0241] Equation 62 can set the total optical axis length (TTL) of the optical system and the optical axis distance (BFL) between the image sensor 190 and the last lens. When the optical system 1000 according to the embodiment satisfies Equation 62, the optical system 1000 can ensure the BFL and can be provided in a thin and compact form. Equation 62 can satisfy... .

[0242] [Formula 63]

[0243] Equation 63 allows setting the total focal length F and total optical axis length TTL of the optical system 1000. Therefore, a thin and compact optical system can be provided. Preferably, Equation 63 can satisfy... .

[0244] [Formula 64]

[0245] Equation 64 can be used to set the total focal length F of the optical system 1000 and the optical axis distance BFL between the image sensor 190 and the last lens. When the optical system 1000 according to the embodiment satisfies Equation 64, the optical system 1000 can have a predetermined field of view and an appropriate focal length, and can be provided as a thin and compact optical system. Furthermore, the optical system 1000 can minimize the distance between the last lens and the image sensor 190, thereby exhibiting good optical characteristics in the peripheral portion of the FOV. Preferably, Equation 64 can satisfy... .

[0246] [Formula 65]

[0247] Equation 65 can be used to set the total focal length F of the optical system 1000 and the diagonal length ImgH of the image sensor 190 from the optical axis. Such an optical system 1000 can have improved aberration characteristics. Preferably, Equation 65 can satisfy... .

[0248] [Formula 66]

[0249] Equation 66 allows setting the total focal length F and the entrance pupil diameter EPD of the optical system 1000. Therefore, the overall brightness of the optical system can be controlled. Preferably, Equation 66 can satisfy... .

[0250] [Formula 67]

[0251] In Equation 67, the optical axis distance BFL between the image sensor 190 and the last lens, and the optical axis distance TD between the lenses can be set, and when Equation 67 is satisfied, the optical system 1000 can be provided as a thin and compact optical system. Preferably, Equation 67 can satisfy... .when When the value exceeds 0.3, the BFL is designed to be larger relative to the TD, thus increasing the overall size of the optical system and making it difficult to miniaturize. Furthermore, because the distance between the sixth lens and the image sensor increases, the amount of unwanted light passing between them may increase, leading to problems such as deterioration of aberration characteristics and reduced resolution.

[0252] [Formula 68]

[0253] In Equation 68, the relationship between the incident pupil diameter EPD, the length ImgH corresponding to half the maximum diagonal length of the image sensor, and the field of view (FOV) can be set. Therefore, the overall size and brightness of the optical system can be controlled. Preferably, Equation 68 can satisfy... .

[0254] [Formula 69]

[0255] Equation 69 can set the relationship between the field of view and the F-number of the optical system. Preferably, Equation 69 can satisfy... .

[0256] [Formula 70]

[0257] When the refractive indices Nd1 and Nd2 of the first and second lenses at the d-line in Equation 70 satisfy the above-mentioned range, the optical system can improve the resolution of the incident light. Preferably, the condition can be satisfied. In other words, the refractive index of the glass and plastic lenses adjacent to the object can be set.

[0258] [Formula 71]

[0259] When the refractive indices Nd3 and Nd4 of the third and fourth lenses at the d-line in Equation 71 satisfy the above-mentioned range, the optical system can improve the resolution of the incident light for the second lens group LG2. Preferably, Equation 71 can satisfy... In other words, the refractive index of the glass lens and plastic lens adjacent to the aperture stop can be set.

[0260] [Equation 72]

[0261] When the refractive index Nd1 and Abbe number Vd1 of the first lens and the refractive index Nd3 and Abbe number Vd3 of the third lens satisfy Equation 72, the dispersion of light transmitted through the first and third lenses made of glass material can be controlled.

[0262] [Formula 73]

[0263] When the refractive index Nd1 and Abbe number Vd1 of the first lens and the refractive index Nd3 and Abbe number Vd3 of the third lens satisfy Equation 73, the dispersion of light transmitted through the first lens made of glass and the third lens made of plastic can be controlled.

[0264] [Formula 74]

[0265] When the refractive index Nd2 and Abbe number Vd2 of the second lens satisfy Equation 74, the dispersion of light transmitted through the first lens made of glass and the second lens made of plastic can be controlled.

[0266] [Formula 75]

[0267] TD_LG2 is the optical axis distance of the second lens group, TD_LG1 is the optical axis distance of the first lens group, and n is the total number of lenses. According to Equation 75, the optical axis distance of each lens group can be set based on the total number of lenses. The optical axis distance of the first lens group is the distance from the object-side surface of the first lens to the sensor-side surface of the second lens, and the optical axis distance of the second lens group is the distance from the object-side surface of the third lens to the sensor-side surface of the sixth lens.

[0268] [Formula 76]

[0269] According to Equation 76, the sum of the thicknesses of the lenses and the sum of the distances between the lenses can be set based on the total number of lenses.

[0270] [Formula 77]

[0271] Preferably, based on the field of view and the number of lenses n, Equation 77 can be used to set the total optical axis length, and the conditions can be met. .

[0272] [Formula 78]

[0273] [Formula 79]

[0274] [Formula 80]

[0275] In Equation 80, the number of glass lenses GLn and the number of plastic lenses PLn in the lens unit can be set. In Equations 74 to 80, n is the total number of lenses, and the relationships between the optical axis distance TD_LG1 of the first lens group LG1, the optical axis distance TD_LG2 of the second lens group LG2, the maximum center thickness CT_Max of the lens, the maximum center distance CG_max, FOV, TTL, and the optical axis distance TD of the lens can be set according to the total number of lenses. Therefore, the chromatic aberration, resolution, size, etc., of an optical system with seven or fewer lenses can be controlled.

[0276] [Formula 81]

[0277]

[0278] In Equation 81, Z can represent the sag, and can refer to the distance from any position on the aspherical surface to the vertex of the aspherical surface in the direction of the optical axis. Y can refer to the distance from any position on the aspherical surface to the optical axis in the direction perpendicular to the optical axis. c can represent the curvature of the lens, and K can represent the conic constant. In addition, A, B, C, D, E, F, etc. can represent aspherical constants.

[0279] The optical system 1000 according to the embodiment can satisfy at least one or two or more of Equations 1 to 80. In this case, the optical system 1000 can have improved optical characteristics. Specifically, when the optical system 1000 satisfies at least one or two or more of Equations 1 to 80, the optical system 1000 can have improved resolution and improved aberration and distortion characteristics. Furthermore, the optical system 1000 can ensure that the BFL (Browser-Fluid Field) is suitable for using an image sensor 190 with a large size, and can minimize the distance between the last lens and the image sensor 190, thereby achieving good optical performance in the central and peripheral portions of the FOV. In addition, when the optical system 1000 satisfies at least one of Equations 1 to 80, the optical system 1000 can include an image sensor 190 with a relatively large size and can have a relatively small TTL (Total Time-Limited) value, thereby providing a thinner and more compact optical system and a camera module having the optical system.

[0280] Table 1 relates to the terms of the above formula in the optical system 1000 according to the embodiment, and relates to the TTL, BFL, F value corresponding to the total effective focal length, ImgH, focal lengths F1, F2, F3, F4, F5 and F6 of the first lens to the sixth lens, edge thickness mm, combined focal length, etc. of the optical system 1000.

[0281] [Table 1]

[0282]

[0283] Table 2 involves Figure 1 The optical system 1000 contains the results of Equations 1 to 40 described above. Referring to Table 2, it can be seen that the optical system 1000 satisfies at least one, two or more, or three or more of Equations 1 to 40. In detail, it can be seen that the optical system 1000 according to the embodiment satisfies all of Equations 1 to 40. Therefore, the optical system 1000 can improve the optical performance and optical characteristics at the central and peripheral portions of the field of view (FOV).

[0284] [Table 2]

[0285]

[0286]

[0287] Table 3 involves Figure 1 The optical system 1000 contains the results of equations 41 to 80 described above. Referring to Table 3, the optical system 1000 can satisfy at least one, two, or more of equations 1 to 40, and can satisfy at least one, two, or more, or three or more of equations 41 to 80. In detail, it can be seen that the optical system 1000 according to the embodiment satisfies all of equations 1 to 80. Therefore, the optical system 1000 can improve the optical performance and optical characteristics at the central and peripheral portions of the FOV.

[0288] [Table 3]

[0289]

[0290]

[0291]

[0292] Figure 15 This is an example of a plan view of a vehicle employing a camera device module or optical system according to an embodiment of the present invention. (Refer to...) Figure 15According to an embodiment of the present invention, a camera system for a vehicle 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 disposed in the vehicle and may capture the front side of the vehicle and / or the driver to generate a front image of the vehicle or an interior image of the vehicle. The image generation unit 11 may generate a surrounding image of the vehicle by capturing the surrounding environment of the vehicle in one or more directions and the front side of the vehicle using the camera module 31. Here, the front image and the surrounding image may be digital images and may include color images, black and white images, infrared images, etc. Furthermore, the front image and the surrounding image may include static images and dynamic images. The image generation unit 11 provides the driver image, the front image, and the surrounding image to the control unit 14. Subsequently, the first information generation unit 12 may include at least one radar and / or camera device disposed in the vehicle and may detect the front side of the vehicle to generate first sensing information. Specifically, the first information generation unit 12 is installed in the vehicle and can detect the position and speed of vehicles in front of the vehicle, the presence and position of pedestrians, etc., to generate first sensing information.

[0293] The first sensing information generated by the first information generation unit 12 can be used to perform control, thereby maintaining a constant distance between the vehicle and the vehicle in front, and improving the vehicle's driving stability under predetermined specific conditions (e.g., when the driver intends to change the vehicle's driving lane or during reversing). The first information generation unit 12 provides the first sensing information to the control unit 14. The second information generation units 21, 22, 23, 24, 25, and 26 generate second sensing information by detecting various side areas of the vehicle based on the forward image generated by the image generation unit 11 and the first sensing information generated by the first information generation unit 12. Specifically, the second information generation units 21, 22, 23, 24, 25, and 26 may include at least one radar and / or camera device installed in the vehicle, and can detect the position and speed of vehicles located in the side areas of the vehicle or capture their images. Here, the second information generation units 21, 22, 23, 24, 25, and 26 may be respectively installed at the two front corners, side mirrors, rear center, and two rear corners of the vehicle.

[0294] At least one information generation unit of the vehicle camera system may include an optical system according to the above-disclosed embodiments and a camera module having the optical system, and information acquired through the front, rear, side or corner areas of the vehicle may be provided to the user or processed to protect the vehicle and objects or protect the vehicle and objects from surrounding safety risks during autonomous driving.

[0295] For safety regulations, to enhance autonomous driving capabilities, and to improve convenience, the optical systems of various camera device modules according to embodiments of the present invention can be installed in vehicles. Furthermore, the optical systems of the camera device modules are used in vehicles as control components for systems such as Lane Keeping Assist System (LKAS), Lane Departure Warning System (LDWS), and Driver Monitoring System (DMS). Such camera device modules for vehicles can achieve stable optical performance even under varying ambient temperatures and can be provided at a competitive cost, thereby ensuring the reliability of components used in vehicles.

[0296] Figure 16 This is an accompanying drawing illustrating a camera device module applied to a mobile terminal according to an embodiment. (Refer to...) Figure 16 The mobile terminal 1 may include a camera module 10 disposed on its rear surface. The camera module 10 may include an image capture function. Furthermore, the camera module 10 may include at least one of an autofocus function, a zoom function, and an OIS function. The camera module 10 can process image frames of still or moving images acquired by the image sensor 190 in image capture mode or video call mode. The processed image frames may be displayed on a display unit (not shown) of the mobile terminal 1 and may be stored in a memory (not shown). Additionally, although not shown in the figures, the camera module may also be disposed on the front surface of the mobile terminal 1. For example, the camera module 10 may include a first camera module 10A and a second camera module 10B. In this case, at least one of the first camera module 10A and the second camera module 10B may include the aforementioned optical system 1000. Therefore, the camera module 10 can have a thin structure and improved distortion and aberration characteristics. Furthermore, the camera module 10 can have good optical performance in the central and peripheral portions of the field of view (FOV).

[0297] Furthermore, the mobile terminal 1 may also include an autofocus device 31. The autofocus device 31 may include an autofocus function using a laser. The autofocus device 31 can be used primarily under conditions where the autofocus function of the image using the camera module 10 disclosed above is degraded (e.g., in close-range environments of 10 m or less, or in dark environments). The autofocus device 31 may include a light-emitting unit and a light-receiving unit, the light-emitting unit including a vertical-cavity surface-emitting laser (VCSEL) semiconductor device, and the light-receiving unit (e.g., a photodiode) configured to convert light energy into electrical energy.

[0298] In addition, the mobile terminal 1 may also include a flash module 33. The flash module 33 may include a light-emitting element configured to emit light in the flash module. The flash module 33 can be operated by the camera device of the mobile terminal or by user control.

[0299] 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 one embodiment. Furthermore, the features, structures, effects, etc., exemplified in each embodiment can be implemented or modified by those skilled in the art in combination with other embodiments. Therefore, anything relating to such combinations and modifications should be interpreted as being included within the scope of the present invention. Moreover, although embodiments have been primarily described above, they are merely examples and do not limit the present invention, and those skilled in the art will understand that various modifications and applications not illustrated above can be made without departing from the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments can be implemented using modifications. Differences related to such modifications and applications should be interpreted as being included within the scope of the present invention as defined by the appended claims.

Claims

1. An optical system, comprising: The first to sixth lenses are positioned along the optical axis from the object towards the sensor side. The first lens has a negative (-) refractive force along the optical axis. The object-side surface of the first lens has a convex shape along the optical axis. The object-side surface of the second lens has a convex shape along the optical axis, and The optical axis distance between the second lens and the third lens is greater than the optical axis distance between the first lens and the second lens.

2. The optical system according to claim 1, in, The center thickness of the sixth lens is the greatest among the center thicknesses of the first lens to the sixth lens.

3. The optical system according to claim 2, in, The third lens has positive refractive power along the optical axis, and The third lens has a crescent shape that protrudes toward the object along the optical axis.

4. The optical system according to claim 2, in, The center thickness of the second lens is greater than the center thickness of the first lens, and The second lens has a meniscus shape that protrudes toward the object along the optical axis.

5. The optical system according to any one of claims 2 to 4, in, The refractive index of the third lens is the largest among the refractive indices of the first lens to the sixth lens.

6. The optical system according to any one of claims 1 to 4, in, At least two of the first to sixth lenses are made of glass. The center thickness of the first lens is less than the center thickness of the lens disposed between the lenses made of the glass material.

7. The optical system according to any one of claims 1 to 4, in, The first lens and the third lens are made of glass material, and The second lens, the fourth lens, the fifth lens, and the sixth lens are made of plastic material.

8. The optical system according to any one of claims 1 to 4, in, The center thickness of the fifth lens is the smallest among the center thicknesses of the first lens to the sixth lens.

9. The optical system according to any one of claims 1 to 4, in, The effective length of the object-side surface and sensor-side surface of each of the third to sixth lenses is less than the diagonal length of the image sensor.

10. An optical system comprising: A first lens group, comprising a first lens and a second lens disposed along the optical axis from the object toward the sensor side; A second lens group is disposed on the sensor side of the first lens group and includes a third to a sixth lens aligned along the optical axis from the object toward the sensor side. as well as An aperture stop is disposed around the region between the third lens and the fourth lens. Wherein, the optical power of the first lens group has a negative (-) value, and The optical axis distance between the second lens and the third lens is greater than the optical axis distance between the first lens and the second lens.

11. The optical system according to claim 10, in, The first lens has negative (-) refractive power and has the largest focal length among the focal lengths of the first lens to the sixth lens, and The sixth lens has a positive (+) refractive power.

12. The optical system according to claim 10, in, One of the lenses in the first lens group is made of glass. At least one lens in the second lens group is made of glass. The first lens has a meniscus shape that bulges toward the object along the optical axis, and The effective length of the first lens is the largest among the effective lengths of the first lens to the sixth lens.

13. The optical system according to any one of claims 10 to 12, in, The optical axis distance between the second lens and the third lens is CG2. The center thickness of the sixth lens is CT6, and Among them, the following equation is satisfied: 。 14. The optical system according to claim 11 or 12, in, The third lens has the largest refractive index among the first to the sixth lenses. The optical axis distance between the second lens and the third lens is CG2. Wherein, the optical axis distance between the first lens and the second lens is CG1, and Wherein, the following equation is satisfied: 。 15. The optical system according to any one of claims 10 to 12, in, The optical axis distance from the sensor-side surface of the sixth lens to the image surface of the image sensor is BFL. The center thickness of the sixth lens is CT6, and Among them, the following equation is satisfied: 。

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