Optical system and image pickup device module including the same

Abstract

An optical system according to one embodiment of the present invention includes first to sixth lenses disposed along an optical axis, in which the first lens has a negative (-) refractive power, the second lens has a positive (+) refractive power, the third lens has a positive (+) refractive power, the fourth lens has a negative (-) refractive power, the fifth lens has a positive (+) refractive power, and the sixth lens has a positive (+) refractive power. The sixth lens has a negative (-) refractive power, an aperture is provided between the second lens and the third lens, and a distance between the first lens and the second lens is the largest among distances on the optical axis between adjacent lenses.

Description

Technical Field

[0001] The present embodiment relates to an optical system having improved optical performance and an image pickup device module including the optical system. Background Art

[0002] ADAS (Advanced Driver Assistance System) is an advanced driver assistance system that assists the driver in driving, and includes a configuration for sensing the situation ahead, determining the situation based on the sensing result, and controlling the vehicle's behavior based on the situation. For example, an ADAS sensor device detects the vehicle ahead and identifies the lane. Afterwards, when the target lane, target speed, and target ahead are determined, the vehicle's ESC (Electronic Stability Control), EMS (Engine Management System), MDPS (Motor Driven Power Steering), etc. are controlled. Representative examples of ADAS may include an automatic parking system, a low-speed city driving assistance system, and a blind spot warning system.

[0003] Sensor devices used to detect the front situation in ADAS include GPS sensors, laser scanners, front radars and lidars, and the most representative sensor device is a camera device used to capture the front, rear and sides of the vehicle.

[0004] These cameras can be placed outside or inside the vehicle to monitor the vehicle's surroundings. Additionally, cameras can be placed inside the vehicle to monitor the driver and passengers. For example, a camera can be positioned adjacent to the driver to capture the driver's health, whether the driver is drowsy, or has consumed alcohol. Furthermore, a camera can be positioned adjacent to a passenger to capture the passenger's sleep patterns, health, and other information, providing the driver with information about the passenger.

[0005] In particular, the most important element for capturing images from an imaging device is the imaging lens that forms the image. Recently, interest in high definition and resolution has been increasing, and research into optical systems comprising multiple lenses is underway to achieve this. However, when an imaging device is exposed to harsh environments such as high temperatures, low temperatures, moisture, or high humidity outside or inside a vehicle, the characteristics of the optical system change. In such situations, it is difficult to consistently achieve excellent optical and aberration characteristics for the imaging device.

[0006] In addition, since the vehicle camera module is exposed to the outside, the shooting quality may be degraded by humidity and temperature. In particular, the camera module has a problem in that the optical characteristics vary depending on the ambient temperature and the material of the lens.

[0007] Therefore, a new optical system and imaging device that can solve the above-mentioned problems are needed. Summary of the Invention

[0008] [Technical Issues]

[0009] An object of the present embodiment is to provide an optical system and a camera module having improved optical characteristics.

[0010] Another object of the present embodiment is to provide an optical system and an imaging device module that can provide excellent optical characteristics in a low-temperature or high-temperature environment.

[0011] In addition, an object of the present embodiment is to provide an optical system and an image pickup device module capable of preventing or minimizing changes in optical characteristics within various temperature ranges.

[0012] Furthermore, this embodiment can provide an imaging device system that can predict and compensate for changes in the focal length of a lens within an imaging device module.

[0013] Furthermore, this embodiment can provide an imaging device system capable of predicting temperature changes of at least one lens in an imaging device module and adjusting the optical axis distance.

[0014] In addition, the present embodiment can provide a control system for controlling an image pickup device module applied to a device or structure that is subject to large temperature changes.

[0015] [Technical Solution]

[0016] In order to solve the above technical problems, an optical system according to a first embodiment of the present disclosure includes: a first lens having positive (+) refractive power; a second lens; and a third lens having negative (-) refractive power, wherein the first to third lenses can be arranged sequentially from the object side to the image side, an aperture can be arranged between the first lens and the second lens, and the thickness of the second lens on the optical axis can be greater than the thickness of the third lens.

[0017] In order to solve the above technical problems, an optical system according to a first embodiment includes: a first lens having positive (+) refractive power; a second lens; and a third lens having negative (-) refractive power, wherein the first lens to the third lens can be arranged sequentially from the object side to the image side, and an aperture can be arranged between the first lens and the second lens, and at least two of the first lens to the third lens can have a refractive index of 1.6 or greater.

[0018] The distance between the first lens and the second lens on the optical axis may be greater than the thickness of the third lens.

[0019] A difference in Abbe numbers of at least two of the first to third lenses may be 0 or more and 10 or less.

[0020] The difference in refractive indices of at least two of the first lens to the third lens may be 0 or greater and 0.1 or less.

[0021] The refractive indices of at least two of the first lens to the third lens may be the same.

[0022] The absolute value of the radius of curvature of the object side surface of the first lens may be less than the absolute value of the radius of curvature of the sensor side of the first lens.

[0023] The absolute value of the radius of curvature of the object side surface of the third lens may be greater than the absolute value of the radius of curvature of the sensor side surface of the third lens.

[0024] The following conditional expression may be satisfied. <Conditional expression> 3 < f < 4 (in the above conditional expression, f means the total focal length of the optical system).

[0025] The following conditional expression may be satisfied. <Conditional expression> 1.8 < Fno < 2.2 (in the above conditional expression, Fno means the F-number of the optical system).

[0026] The following conditional expression may be satisfied. <Conditional expression> 1.6 < n1 < 1.7 (in the above conditional expression, n1 means the refractive index of the first lens).

[0027] The following conditional expression may be satisfied. <Conditional expression> 20 < v1 < 30 (in the above conditional expression, v1 means the Abbe number of the first lens). [[ID=

[22]

[0028] The following conditional expression may be satisfied. <Conditional expression> 0.5 < f1 / f2 < 1 (in the above conditional expression, f1 is the focal length of the first lens, and f2 is the focal length of the second lens).

[0029] The following conditional expression may be satisfied. <Conditional expression> 5 < TTL < 6 (in the above conditional expression, TTL is the distance along the optical axis from the object side of the first lens to the image sensor).

[0030] The second lens may have a positive (+) refractive power.

[0031] To solve the above technical problems, an optical system according to another embodiment of the present disclosure includes a first lens to a sixth lens arranged along the optical axis, wherein the first lens may have a negative (-) refractive power, the second lens may have a positive (+) refractive power, the third lens may have a positive (+) refractive power, the fourth lens may have a negative (-) refractive power, the fifth lens may have a positive (+) refractive power, the sixth lens may have a negative (-) refractive power, an aperture may be arranged between the second lens and the third lens, and among the distances on the optical axis between adjacent lenses, the distance between the first lens and the second lens may be the largest.

[0032] At least one of the first lens and the third lens may be made of glass, and at least one of the second lens, the fourth lens, and the fifth lens may be made of plastic.

[0033] Among the first lens to the sixth lens, the second lens may have the largest thickness on the optical axis.

[0034] The second lens may have a meniscus shape protruding toward the sensor.

[0035] The fifth lens may have convex surfaces on both sides.

[0036] The sixth lens may have a meniscus shape protruding toward the sensor.

[0037] The following conditional expression may be satisfied. <Conditional expression> 10 < TTL < 15 (in the above conditional expression, TTL means the distance on the optical axis from the object side of the first lens to the upper surface of the image sensor).

[0038] The following conditional expression may be satisfied. <Conditional expression> 0.3 < ΣCT / TTL < 0.8 (in the above conditional expression, ΣCT means the sum of the central thicknesses of the first lens to the sixth lens, and TTL means the distance on the optical axis from the object side of the first lens to the upper surface of the image sensor).

[0039] The following conditional expression may be satisfied. <Conditional expression> 0.5 < CA_L1 / CA_L6 < 1.5 (in the above conditional expression, CA_L1 means the clear aperture of the first lens, and CA_L6 means the clear aperture of the sixth lens).

[0040] To solve the above technical problems, the optical system according to the first embodiment includes the first lens to the sixth lens arranged along the optical axis, wherein the second lens may have a positive (+) refractive power, the fourth lens may have a negative (-) refractive power, the fifth lens may have a positive (+) refractive power, the sixth lens may have a negative (-) refractive power. Among the first lens to the sixth lens, the second lens may have the largest thickness on the optical axis, the fifth lens has a convex shape on both sides, and the sixth lens may have a meniscus shape protruding toward the sensor side.

[0041] Among the first lens to the sixth lens, the clear aperture of the first lens may be the largest, and among the first lens to the sixth lens, the clear aperture of the third lens may be the smallest.

[0042] Among the distances between adjacent lenses on the optical axis, the distance between the third lens and the fourth lens may be the smallest.

[0043] The distance between the second lens and the third lens on the optical axis can be less than the distance between the fifth lens and the sixth lens.

[0044] The following conditional expression can be satisfied. <Conditional expression> 1.5 < TTL / ImgH < 2.5 (In the above conditional expression, TTL means the distance on the optical axis from the object side of the first lens to the upper surface of the image sensor, and ImgH means 1 / 2 of the maximum diagonal length of the image sensor on the optical axis).

[0045] The following conditional expression can be satisfied. <Conditional expression> 1 < ΣCT / ΣCG < 2.5 (In the above conditional expression, ΣCT means the sum of the central thicknesses of the first lens to the sixth lens on the optical axis, and ΣCG means the sum of the distances between adjacent lenses on the optical axis).

[0046] [Advantageous Effects]

[0047] The optical system and the imaging device module according to the embodiment can have improved optical characteristics. Specifically, in the optical system according to the embodiment, the plurality of lenses can have set thicknesses, refractive powers, and distances from adjacent lenses. Therefore, the optical system and the imaging device module according to the embodiment can have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. within a set field of view, and can have good optical performance in the periphery of the field of view.

[0048] In addition, the optical system and the imaging device module according to the embodiment can have good optical performance within a temperature range from low temperature to high temperature (-40°C to 105°C). Specifically, the plurality of lenses included in the optical system can have set materials, refractive powers, and refractive indices. Therefore, when the refractive index of each lens changes according to temperature change and the focal length of each lens changes due to this, the plastic lens and the glass lens can compensate for each other. In other words, the optical system can effectively perform the distribution of refractive power within a temperature range from low temperature to high temperature, and can prevent or minimize the change in optical characteristics within a temperature range from low temperature to high temperature. Therefore, the optical system and the imaging device module according to the embodiment can maintain improved optical characteristics within various temperature ranges.

[0049] In addition, the optical system and the imaging device module according to the embodiment can satisfy a set field of view by mixing plastic lenses and glass lenses, and can achieve excellent optical characteristics. Therefore, the optical system can provide a thinner vehicle imaging device module. Therefore, the optical system and the imaging device module can be provided for various applications and devices, and can have excellent optical characteristics even in a harsh temperature environment, for example, when exposed to the outside or inside of a vehicle at high temperature in summer.

[0050] Furthermore, variations in the back focal length (BFL) of the camera module can be compensated. Furthermore, at least one lens can be moved along the optical axis in response to temperature changes, minimizing performance variations. Furthermore, ambient temperature information of the camera module can be detected from a device inside or outside the vehicle, and the distance between at least one lens and the sensor can be adjusted within a predictable range for each temperature. Consequently, performance variations depending on the camera module's temperature can be minimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a plan view of a vehicle to which the camera module or the optical system according to the first embodiment is applied.

[0052] Figure 2 and Figure 3 1 is a diagram showing the interior of a vehicle to which the camera module or the optical system according to the first embodiment is applied.

[0053] Figure 4 is a configuration diagram of an optical system according to the first embodiment.

[0054] Figure 5 This is a graph showing the diffraction MTF characteristics of an optical system in a low-temperature (-40°C) environment.

[0055] Figure 6 is a graph showing the diffraction MTF characteristics of an optical system in which a peak reference is compensated according to actuator operation in a low temperature (-40°C) environment.

[0056] Figure 7 This is a graph showing the aberration of an optical system in a low temperature (-40°C) environment.

[0057] Figure 8 This is a graph showing the diffraction MTF characteristics of an optical system at room temperature (20°C).

[0058] Figure 9 This is a graph showing the diffraction MTF characteristics of an optical system in which the peak reference is compensated according to actuator driving at room temperature (20°C).

[0059] Figure 10 This is a graph showing the aberrations of the optical system at room temperature (20°C).

[0060] Figure 11 This graph shows the diffraction MTF characteristics of an optical system in a high temperature (85°C) environment.

[0061] Figure 12 Graph showing the diffraction MTF characteristics of an optical system in which the peak reference is compensated according to actuator driving in a high temperature (85°C) environment.

[0062] Figure 13 This graph shows the aberrations of the optical system in a high temperature (85°C) environment.

[0063] Figure 14 is a side sectional view of an optical system and an image pickup device module having the optical system according to a second embodiment.

[0064] Figure 15 It shows Figure 14 A table of aspheric coefficients of lenses in an optical system.

[0065] Figure 16 It shows Figure 14 A table showing the thickness of each lens of an optical system and the distances between adjacent lenses.

[0066] Figure 17 It shows Figure 14 A table showing sag values ​​of the lens surfaces of the first to sixth lenses of the optical system.

[0067] Figure 18 Is to show about Figure 14 A graph showing the diffraction MTF (Modulation Transfer Function) data of an optical system at low temperatures.

[0068] Figure 19 Is to show about Figure 14 This graph shows the aberration characteristics of an optical system at low temperatures.

[0069] Figure 20 Is to show about Figure 14 A graph showing the diffraction MTF data of an optical system at room temperature.

[0070] Figure 21 Is to show about Figure 14 A graph showing the aberration characteristics of an optical system at room temperature.

[0071] Figure 22 Is to show about Figure 14 A graph showing the diffraction MTF data of an optical system at high temperatures.

[0072] Figure 23 Is to show about Figure 14 This graph shows the aberration characteristics of an optical system at high temperatures.

[0073] Figure 24 Is to show about Figure 14 A graph showing the diffraction MTF data of an optical system at RGB wavelengths.

[0074] Figure 25 Is to show about Figure 14A graph showing the diffraction MTF data of an optical system at IR wavelengths.

[0075] Figure 26 is a cross-sectional side view of an optical system and an image pickup device module having the optical system according to a third embodiment.

[0076] Figure 27 It shows Figure 26 A table of aspheric coefficients of lenses in an optical system.

[0077] Figure 28 It shows Figure 26 A table showing the thickness of each lens in an optical system and the distances between adjacent lenses.

[0078] Figure 29 It shows Figure 26 A table showing sag values ​​of the lens surfaces of the first to sixth lenses in the optical system.

[0079] Figure 30 Is to show about Figure 26 A graph showing the diffraction MTF (Modulation Transfer Function) data of an optical system at low temperatures.

[0080] Figure 31 Is to show about Figure 26 This graph shows the aberration characteristics of an optical system at low temperatures.

[0081] Figure 32 Is to show about Figure 26 A graph showing the diffraction MTF data of an optical system at room temperature.

[0082] Figure 33 Is to show about Figure 26 A graph showing the aberration characteristics of an optical system at room temperature.

[0083] Figure 34 Is to show about Figure 26 A graph showing the diffraction MTF data of an optical system at high temperatures.

[0084] Figure 35 Is to show about Figure 26 This graph shows the aberration characteristics of an optical system at high temperatures.

[0085] Figure 36 Is to show about Figure 26 A graph showing the diffraction MTF data of an optical system at RGB wavelengths.

[0086] Figure 37 Is to show about Figure 26 A graph showing the diffraction MTF data of an optical system at IR wavelengths.

[0087] Figure 38 is a cross-sectional side view of an optical system and an image pickup device module including the optical system according to a fourth embodiment.

[0088] Figure 39 It shows Figure 38 A table of aspheric coefficients of lenses in an optical system.

[0089] Figure 40 It shows Figure 38 A table showing the thickness of each lens of an optical system and the distances between adjacent lenses.

[0090] Figure 41 It shows Figure 38 A table showing sag values ​​of the lens surfaces of the first to sixth lenses in the optical system.

[0091] Figure 42 Is to show about Figure 38 A graph showing the diffraction MTF (Modulation Transfer Function) data of an optical system at low temperatures.

[0092] Figure 43 Is to show about Figure 38 This graph shows the aberration characteristics of an optical system at low temperatures.

[0093] Figure 44 Is to show about Figure 38 A graph showing the diffraction MTF data of an optical system at room temperature.

[0094] Figure 45 Is to show about Figure 38 A graph showing the aberration characteristics of an optical system at room temperature.

[0095] Figure 46 Is to show about Figure 38 A graph showing the diffraction MTF data of an optical system at high temperatures.

[0096] Figure 47 Is to show about Figure 38 This graph shows the aberration characteristics of an optical system at high temperatures.

[0097] Figure 48 Is to show about Figure 38 A graph showing the diffraction MTF data of an optical system at RGB wavelengths.

[0098] Figure 49 Is to show about Figure 38 A graph showing the diffraction MTF data of an optical system at IR wavelengths.

[0099] Figure 50This is a diagram showing an imaging device system according to this embodiment.

[0100] Figure 51 (A) and Figure 51 (B) is a diagram illustrating changes in the focal length of the lens in the camera module according to temperature.

[0101] Figure 52 1 is a cross-sectional side view showing an example of an imaging device module in the imaging device system according to the present embodiment.

[0102] Figure 53 This is a table showing lens correction ratios according to temperature, stored in the storage device of the imaging device system according to the present embodiment.

[0103] Figure 54 Graph showing the lens correction ratio according to temperature in the imaging device system of this embodiment.

[0104] Figure 55 FIG. 1 is a diagram showing a table illustrating a temperature compensation rate according to a reference BFL stored in a storage device of the imaging device system according to the present embodiment.

[0105] Figure 56 Graphs illustrating a focus correction method according to temperature in the imaging device system of this embodiment.

[0106] Figure 57 It is a configuration diagram for explaining some terms in the optical system according to this embodiment. DETAILED DESCRIPTION

[0107] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0108] However, the technical concept of the present disclosure is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical concept of the present disclosure, one or more of the components between the embodiments can be selectively combined or replaced and used.

[0109] In addition, unless clearly and specifically defined and described otherwise, the terms (including technical terms and scientific terms) used in the first embodiment may be interpreted as meanings that can be generally understood by ordinary technicians in the technical field to which the first embodiment belongs, and commonly used terms such as terms defined in a dictionary may be interpreted taking into account the contextual meaning of the relevant technology.

[0110] In addition, the terms used in the first embodiment are used to describe the embodiment and are not intended to limit the present disclosure.

[0111] In this specification, unless otherwise specifically stated in the phrase, the singular may also include the plural, and when it is described as "at least one (or one or more) of A, B, C", it may include one or more of all combinations that can be combined with A, B, C.

[0112] In addition, when describing the components of the first embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish a component from other components and are not intended to limit the nature, order, or sequence of the components.

[0113] In addition, when a component is described as being “connected,” “coupled” or “linked” to another component, it may include not only the case where the component is directly “connected,” “coupled” or “linked” to the other component, but also the case where the component is “connected,” “coupled” or “linked” to the other component through another component between the component and the other component.

[0114] In addition, when it is described as being formed or arranged "above" or "below" each component, "above" or "below" includes not only a case where the two components are in direct contact with each other, but also a case where one or more other components are formed or arranged between the two components. In addition, when expressed as "above" or "below", it can include the meaning of a downward direction as well as an upward direction based on one component.

[0115] In addition, a convex surface of a lens may mean that the lens surface on the optical axis region has a convex shape, and a concave surface of a lens may mean that the lens surface on the optical axis region has a concave shape.

[0116] In addition, the "object side" may refer to the lens surface facing the object side based on the optical axis, and the "sensor side" may refer to the lens surface facing the image sensor based on the optical axis. The "object side" may be the "material side." The "sensor side" may be the "image side."

[0117] In addition, the vertical direction may mean a direction perpendicular to the optical axis, and the end of the lens or the lens surface may mean the farthest end of the effective area of ​​the lens through which incident light passes.

[0118] In addition, the center thickness of the lens may mean the length in the optical axis direction between the object side and the sensor side along the optical axis of the lens.

[0119] Additionally, depending on the measurement method, etc., the size of the clear aperture of the lens surface may have a measurement error of up to ±0.4 mm.

[0120] In addition, in an embodiment, low temperature may mean a specific temperature (-40° C.) or a temperature range of about -40° C. to about 30° C., and room temperature may mean a specific temperature (20° C.) or a temperature range of about 18° C. to about 30° C. In addition, high temperature may mean a specific temperature (85° C.) or a temperature range of about 80° C. to about 105° C.

[0121] Figure 1 is a plan view of a vehicle to which the camera module or the optical system according to the first embodiment is applied, and Figure 2 and Figure 3 1 is a diagram showing the interior of a vehicle to which the camera module or the optical system according to the first embodiment is applied.

[0122] First, refer to Figure 1 The vehicle camera system according to the first embodiment of the present disclosure includes an image generating portion 2110 , a first information generating portion 2120 , second information generating portions 2210 , 2220 , 2230 , 2240 , 2250 , 2260 and a control portion 2140 .

[0123] The image generation unit 2110 may include at least one first camera module 2310 disposed outside or inside the vehicle 2000 and may generate an image of the front of the vehicle 2000. Furthermore, the image generation unit 2110 may use the first camera module 2310 to capture not only the front of the vehicle 2000 but also the surroundings of the vehicle 2000 in one or more directions to generate an image of the surroundings of the vehicle 2000. 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 still images and moving images. The image generation unit 2110 may provide the front image and the surrounding image to the control unit 2140.

[0124] Next, the first information generating unit 2120 may include at least one radar and / or camera device placed in the vehicle 2000, and detect the front of the vehicle 2000 to generate first detection information. Specifically, the first information generating unit 2120 may be placed in the vehicle 2000, and detect the position and speed of the vehicle 2000 located in front of the vehicle 2000, whether there is a pedestrian, and the position of the pedestrian, etc., to generate the first detection information.

[0125] Using the first detection information generated by the first information generating unit 2120, the distance between the vehicle 2000 and the preceding vehicle can be controlled to be maintained at a constant level, and in pre-set specific situations, such as when the driver wants to change the driving lane of the vehicle 2000 or when reverse parking, the driving stability of the vehicle 2000 can be improved. The first information generating unit 2120 can provide the first detection information to the control unit 2140.

[0126] Next, second information generating units 2210, 2220, 2230, 2240, 2250, and 2260 detect each side of vehicle 2000 and generate second detection information based on the front image generated by image generating unit 2110 and the first detection information generated by first information generating unit 2120. Specifically, second information generating units 2210, 2220, 2230, 2240, 2250, and 2260 may include at least one radar and / or camera device provided in vehicle 2000 and may detect the position and speed of vehicles located to the side of vehicle 2000 or capture images. Here, second information generating units 2210, 2220, 2230, 2240, 2250, and 2260 may be positioned at the two front corners, the side mirrors, and the rear center and two rear corners of vehicle 2000, respectively.

[0127] In addition, refer to Figure 2 and Figure 3 , the image generation part 2110 may include at least one second camera module 2320 positioned inside the vehicle 2000. The second camera module 2320 may be positioned adjacent to the driver and the passenger. For example, the second camera module 2320 may be positioned at a first distance d1 from the driver and the passenger to generate an interior image of the vehicle 2000. In this case, the first distance d1 may be approximately 500 mm or greater. In detail, the first distance d1 may be approximately 600 mm or greater. In addition, the second camera module 2320 may have a field of view (FOV) of approximately 55 degrees or greater.

[0128] Image generation unit 2110 can use second camera module 2320 to capture the driver and / or passengers inside vehicle 2000 to generate an interior image of vehicle 2000. The interior image of the vehicle can be a digital image and can include color images, black and white images, infrared images, etc. Furthermore, the interior image can include still images and moving images. Image generation unit 2110 provides the interior image of vehicle 2000 to control unit 2140.

[0129] The control unit 2140 can provide information to the passengers of the vehicle 2000 based on the information provided by the image generation unit 2110. For example, the control unit 2140 can detect the driver's health, whether he or she is sleepy, whether he or she has drunk alcohol, etc. based on the information provided by the image generation unit 2110, and can provide the driver with corresponding information, such as guidance and warnings. In addition, the control unit 2140 can detect the sleeping condition, health status, etc. of the passengers based on the information provided by the image generation unit 2110, and can provide information about the same to the driver and / or passengers.

[0130] The vehicle camera system may include a camera module having an optical system 1000 according to the first embodiment described below, and may provide or process information obtained from the front, rear, sides, or corners of the vehicle 2000 to the user, thereby protecting the vehicle 2000 and objects from autonomous driving or surrounding safety. Furthermore, the vehicle camera system may be placed inside the vehicle 2000 to provide various information to the driver and passengers. In other words, at least one of the first camera module 2310 and the second camera module 2320 may include the optical system 1000, which will be described later.

[0131] The multiple optical systems of the camera module according to the first embodiment can be installed in a vehicle for safety adjustments, enhanced autonomous driving functions, and increased convenience. Furthermore, the optical systems of the camera module are used in vehicles as components for controlling systems such as lane keeping assist systems (LKAS), lane departure warning systems (LDWS), and driver monitoring systems (DMS). Such a vehicle camera module can achieve stable optical performance even under varying ambient temperatures and can provide a competitively priced module, thereby ensuring the reliability of vehicle components.

[0132] The optical system according to the first embodiment will be described in detail below.

[0133] The optical system 1000 according to the first embodiment may include a plurality of lenses 101 and an image sensor 600. Specifically, the optical system 1000 according to the first embodiment may include two or more lenses. For example, the optical system 1000 may include three lenses, and may include a first lens 101, a second lens 102, a third lens 103, and the image sensor 600, arranged sequentially from the object side to the sensor side. The first to third lenses 101 to 103 may be arranged sequentially along the optical axis OA of the optical system 1000.

[0134] In this case, light corresponding to information of the object may pass through the first lens 101 , the second lens 102 , and the third lens 103 and be incident on the image sensor 600 .

[0135] Each of the plurality of lenses 101 to 103 may include an active region and an inactive region. The active region may be a region through which light incident on each of the first to third lenses 101 to 103 passes. In other words, the active region may be a region where the incident light is refracted and optical characteristics are achieved. The active region may be a clear aperture region.

[0136] The inactive area can be arranged around the active area. The inactive area can be an area where light does not enter. In other words, the inactive area can be an area that is not related to optical properties. Alternatively, the inactive area can be an area fixed to the lens barrel (not shown) that houses the lens. The inactive area can be a non-clear aperture area.

[0137] The image sensor 600 can detect light. Specifically, the image sensor 600 can detect light that has sequentially passed through a plurality of lenses, specifically, the first lens 101 to the third lens 103. The image sensor 600 may include a device capable of detecting incident light, such as a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor).

[0138] Image sensor 600 may include a plurality of pixels having a predetermined size. For example, the pixel size of image sensor 600 may be approximately 3 μm. Image sensor 600 may detect light of a predetermined wavelength. For example, image sensor 600 may detect infrared (IR) light. Specifically, image sensor 600 may detect near-infrared light of approximately 1500 nm or shorter. For example, the image sensor may detect light in a wavelength band of approximately 880 nm to approximately 1000 nm.

[0139] The optical system 1000 according to the first embodiment may further include a cover glass 400 and an optical filter 500 .

[0140] The cover glass 400 may be placed between the plurality of lenses 101 to 103 and the image sensor 600. The cover glass 400 may be placed adjacent to the image sensor 600. The cover glass 400 may have a shape corresponding to the image sensor 600. The cover glass 400 may be provided with a size greater than or equal to that of the image sensor 600 to protect the upper portion of the image sensor 600.

[0141] In addition, the optical filter 500 may be placed between the plurality of lenses 101 to 103 and the image sensor 600. The optical filter 500 may be placed between the last lens (third lens 103) closest to the image sensor 600 among the plurality of lenses 101 to 103 and the image sensor 600. In detail, the optical filter 500 may be placed between the last lens (third lens 103) and the cover glass 400.

[0142] The optical filter 500 can pass light of a set wavelength band and filter light of a different wavelength band. The optical filter 500 can pass light of a wavelength band corresponding to the light received by the image sensor 600 and block light of a wavelength band that does not correspond to the received light. Specifically, the optical filter 500 can pass light of an infrared wavelength band and block ultraviolet light and light of a visible light band. For example, the optical filter 500 can include at least one of an IR pass filter and an IR cut filter.

[0143] The optical system 1000 according to the first embodiment may include an aperture stop (STOP). The aperture stop may be arranged between the first lens 101 and the second lens 102. The aperture stop may be arranged closer to the first lens 101 than the second lens 102. The aperture stop may be spaced apart from the object side of the second lens 102. The aperture stop may control the amount of light incident from the object. The aperture stop may control the amount of light passing through the first lens 101. The aperture stop may control the amount of light incident on the third lens 103. The aperture stop may include an aperture stop.

[0144] Hereinafter, referring to Table 1, a plurality of lenses according to the first embodiment will be described in more detail.

[0145] [Table 1]

[0146]

[0147] Table 1 shows the curvature radius of the first lens 101 to the third lens 103 according to the first embodiment, the thickness of each lens along the optical axis OA, the distance between each lens along the optical axis OA, the refractive index of light in the d-line (587.562 mm) wavelength band, the Abbe number, and the clear aperture (CA) size. The lens data described in Table 1 is data at room temperature (approximately 20° C.).

[0148] Reference Figure 4 1, the first lens 101 of the optical system 1000 according to the first embodiment may be made of plastic and may have positive (+) refractive power on the optical axis OA.

[0149] The first surface S1 on the object side of the first lens 101 on the optical axis OA may have a convex shape, and the second surface S2 on the sensor side may have a convex shape. The first lens 101 may have a convex shape on both sides on the optical axis OA. At least one of the first surface S1 and the second surface S2 may be aspherical. For example, both the first surface S1 and the second surface S2 may be aspherical.

[0150] The second lens 102 may have positive (+) or negative (-) refractive power on the optical axis OA. The second lens 102 may have positive (+) refractive power on the optical axis OA. The second lens (102) may be made of a plastic material.

[0151] The object-side third surface S3 of the second lens 102 on the optical axis OA may have a concave shape, and the sensor-side fourth surface S4 may have a convex shape. The second lens 102 may have a concave meniscus shape on the object side on the optical axis OA. The second lens 102 may have a convex meniscus shape on the sensor side on the optical axis OA. At least one of the third surface S3 and the fourth surface S4 may be aspherical. For example, both the third surface S3 and the fourth surface S4 may be aspherical.

[0152] The third lens 103 may have positive (+) or negative (-) refractive power on the optical axis OA. The third lens 103 may have negative (-) refractive power on the optical axis OA. The third lens 103 may be made of a plastic material.

[0153] The fifth surface S5 on the object side of the third lens 103 on the optical axis OA can have a convex shape, and the sixth surface S6 can be concave. The third lens 103 can have a meniscus shape that is convex toward the object side on the optical axis OA. In contrast, the fifth surface S5 can have a convex shape on the optical axis OA, and the sixth surface S6 can be convex on the optical axis OA. In other words, the third lens 103 can have a biconvex shape on the optical axis OA. In contrast, the fifth surface S5 can have a concave shape on the optical axis OA, and the sixth surface S6 can be convex on the optical axis OA. In other words, the third lens 103 can have a meniscus shape that is convex toward the sensor on the optical axis OA. In contrast, the fifth surface S5 can have a concave shape on the optical axis OA, and the sixth surface S6 can be concave on the optical axis OA. In other words, the third lens 103 can have a shape with both sides concave on the optical axis OA.

[0154] At least one of the fifth surface S5 and the sixth surface S6 may be aspherical. For example, both the fifth surface S5 and the sixth surface S6 may be aspherical. The fifth surface S5 may include at least one inflection point. The fifth surface S5 may include at least one inflection point in the flange region, which is the region outside the clear aperture region. The sixth surface S6 may include at least one inflection point. The sixth surface S6 may include at least one inflection point in the clear aperture region.

[0155] At least two of the first to third lenses 101 to 103 may have a refractive index of 1.6 or greater. At least two of the first to third lenses 101 to 103 may have the same refractive index. The difference in refractive index between at least two of the first to third lenses 101 to 103 may be 0.1 or less. At least two of the first to third lenses 101 to 103 may be high-refractive lenses. When the lenses are made of plastic material, the refractive index of the lenses may be 1.6 or greater and 1.7 or less. For example, the refractive index of the first to third lenses 101 to 103 may all be the same. Thus, when at least two or three of the first to third lenses 101 to 103 have the same refractive index, vehicle optical performance can be ensured, and the lenses can be lightweight and easy to manufacture using plastic lenses.

[0156] The Abbe number of at least two of the first through third lenses 101 through 103 may be 20 or greater and 30 or less. The difference between the Abbe numbers of at least two of the first through third lenses 101 through 103 may be 0 or greater and 10 or less. The Abbe numbers of at least two of the first through third lenses 101 through 103 may be the same. For example, the Abbe numbers of the first through third lenses 101 through 103 may all be the same. Therefore, when the Abbe numbers of at least two or all three of the first through third lenses 101 through 103 are the same, vehicle optical performance can be ensured, and the plastic lenses can be lightweight and easy to manufacture.

[0157] Table 2 below shows sag data according to the vertical height (0.2 mm distance) of the optical axis OA of each of the object side (first surface S1) and the sensor side (second surface S2) of the first lens 101 at room temperature (approximately 20°C).

[0158] Table 3 also shows data regarding lens thickness based on vertical height (0.2 mm distance) from the optical axis OA at room temperature (approximately 20°C). Specifically, D_1 in Table 3 is the center thickness of the first lens 101, which is the thickness of the first lens 101 at the optical axis OA (mm). Furthermore, D_1_ET in Table 3 refers to the thickness of the end of the active area of ​​the first lens 101 in the direction of the optical axis OA (mm). Specifically, D_1_ET refers to the distance (mm) between the end of the active area on the object side (first surface S1) of the first lens 101 and the end of the active area on the sensor side (second surface S2) of the first lens 101 in the direction of the optical axis OA.

[0159] [Table 2]

[0160]

[0161] [Table 3]

[0162] Vertical height from optical axis to optical axis (mm) Thickness of the first lens along the optical axis (mm) 0 1.15(D_1) 0.2 1.13987 0.4 1.10876 0.6 1.05439 0.8 0.97306 1.0 0.86375(D_1_ET)

[0163] [Table 4]

[0164]

[0165]

[0166] Referring to Tables 2 and 3, the thickness of the first lens 101 in the direction of the optical axis OA can be made thinner as it moves from the optical axis OA toward the end of the clear aperture of the first lens 101. Furthermore, Table 4 shows data regarding the tilt angle (degrees) of the first lens on the object side (first surface S1) and the sensor side (second surface S2) of the first lens, according to the vertical height (0.2 mm distance) of the optical axis OA, at room temperature (approximately 20°C). The tilt angle refers to the angle formed by a tangent line contacting the lens surface and a line perpendicular to the optical axis OA.

[0167] Therefore, by controlling incident light, the first lens 101 can have improved aberration control characteristics.

[0168] Table 5 below shows sag data according to the vertical height (0.2 mm distance) of the optical axis OA of each of the object side (third side S3) and the sensor side (fourth side S4) of the second lens 102 at room temperature (about 20°C).

[0169] Table 6 also shows data regarding lens thickness at room temperature (approximately 20°C) based on a vertical height (0.2 mm distance) from the optical axis OA. Specifically, D_2 in Table 6 represents the center thickness of the second lens 102, which is the thickness of the second lens 102 at the optical axis OA (mm). Furthermore, D_2_ET in Table 6 represents the thickness of the end portion of the active area of ​​the second lens 102 in the direction of the optical axis OA (mm). Specifically, it refers to the distance (mm) between the end portion of the active area of ​​the second lens 102 on the object side (third surface S3) and the end portion of the active area of ​​the second lens 102 on the sensor side (fourth surface S4) in the direction of the optical axis OA.

[0170] [Table 5]

[0171]

[0172]

[0173] [Table 6]

[0174] Vertical height from optical axis to optical axis (mm) Thickness of the second lens along the optical axis (mm) 0 1.000(D_2) 0.2 0.996 0.4 0.984 0.6 0.970 0.8 0.962(D_2_ET)

[0175] [Table 7]

[0176]

[0177] Referring to Tables 5 and 6, the thickness of the second lens 102 in the direction of the optical axis OA can be made thinner as it moves from the optical axis OA toward the end of the clear aperture of the second lens 102. Table 7 also shows data regarding the tilt angle (degrees) of the second lens 102 on the object side (third surface S3) and the sensor side (fourth surface S4) of the second lens 102, according to the vertical height (0.2 mm distance) of the optical axis OA at room temperature (approximately 20°C). The tilt angle refers to the angle formed by a tangent line contacting the lens surface and a line perpendicular to the optical axis OA.

[0178] Therefore, the second lens 102 can prevent or minimize a change in optical characteristics according to temperature in a temperature range from low temperature to high temperature.

[0179] Table 8 below shows sag data according to the vertical height (0.2 mm distance) of the optical axis OA of each of the object side (fifth surface S5) and the sensor side (sixth surface S6) of the third lens 103 at room temperature (approximately 20°C).

[0180] Table 9 also shows data regarding lens thickness according to vertical height relative to the optical axis OA at room temperature (approximately 20°C). Specifically, D_3 in Table 9 represents the center thickness of the third lens 103, which is the thickness of the third lens 103 at the optical axis OA (mm). Furthermore, D_3_ET in Table 9 represents the thickness of the end of the active area of ​​the third lens 103 in the direction of the optical axis OA (mm). Specifically, D_3_ET refers to the distance in the direction of the optical axis OA (mm) between the end of the active area of ​​the third lens 103 on the object side (fifth surface S5) and the end of the active area of ​​the third lens 103 on the sensor side (sixth surface S6).

[0181] [Table 8]

[0182]

[0183] [Table 9]

[0184] Vertical height from optical axis to optical axis (mm) Thickness of the third lens along the optical axis (mm) 0 0.800(D_3) 0.2 0.810 0.4 0.839 0.6 0.879 0.8 0.921 1.0 0.959 1.2 0.984 1.4 0.990(D_3_ET)

[0185] [Table 10]

[0186]

[0187] Referring to Tables 8 and 9, the thickness of the third lens 103 in the direction of the optical axis OA can become thicker as it moves from the optical axis OA toward the end of the clear aperture of the third lens 103. Furthermore, Table 10 shows data regarding the tilt angle (degrees) of the third lens 103 on the object side (fifth surface S5) and the sensor side (sixth surface S6) of the third lens 103 according to the vertical height (0.2 mm distance) of the optical axis OA at room temperature (approximately 20°C). The tilt angle refers to the angle formed by a tangent line contacting the lens surface and a line perpendicular to the optical axis OA.

[0188] Therefore, the third lens 103 can prevent or minimize a change in optical characteristics according to temperature in a temperature range from low temperature to high temperature.

[0189] The value of the aspheric coefficient of each lens surface in the optical system 1000 according to the first embodiment is shown in Table 11 below.

[0190] [Table 11]

[0191]

[0192] In addition, the distance (first distance) between the first lens 101 and the second lens 102 in the optical system 1000 according to the first embodiment at room temperature (approximately 20° C.) is shown in Table 12 below.

[0193] [Table 12]

[0194]

[0195]

[0196] Referring to Table 12, the first distance d12 may refer to the distance in the optical axis direction from the sensor side of the first lens 101 to the object side of the second lens 102. The first distance d12 may be the sum of the distance in the optical axis direction from the sensor side of the first lens 101 to the object side of the aperture, and the distance in the optical axis direction from the sensor side of the aperture to the object side of the second lens 102. The first distance d12 may be the first aerial distance d12.

[0197] The first distance may become smaller as it moves from the optical axis OA to the first point L1, which is the end of the clear aperture of the second surface S2. Here, the value represented by the first point L1 is an approximate value of the effective radius value of the second surface S2 having the smaller clear aperture size, of the sensor side (second surface S2) of the first lens 101 and the object side (third surface S3) of the second lens 102 facing each other, and means an approximate value of 1 / 2 of the clear aperture value of the second surface S2 described in Table 2.

[0198] The first distance may have a maximum value at the optical axis OA and a minimum value at the first point L1. The maximum value of the first distance may be about 1 to about 1.3 times the minimum value. For example, in the first embodiment, the maximum value of the first distance may be about 1.03 times the minimum value.

[0199] In addition, the distance (second distance) between the second lens 102 and the third lens 103 in the optical system 1000 according to the first embodiment at room temperature (approximately 20° C.) is shown in Table 13 below.

[0200] [Table 13]

[0201]

[0202]

[0203] Referring to Table 13, the second distance d23 may mean from the sensor side of the second lens to the object side of the third lens along the optical axis direction. The second distance d23 may be a second air distance d23.

[0204] The second distance may increase from the optical axis OA to the second point L2, which is the end of the clear aperture of the fourth surface S4. Here, the value indicated by the second point L2 is an approximate value of the effective radius value of the fourth surface S4 having a smaller clear aperture in the sensor side (fourth surface S4) of the second lens 102 and the object side (fifth surface S5) of the third lens 103 facing each other, and means an approximate value of 1 / 2 of the clear aperture value of the fourth surface S4 described in Table 2.

[0205] The second distance may have a maximum value at the second point L2 and a minimum value at the optical axis OA. The maximum value of the second distance may be about 8 times to about 10 times the minimum value. For example, in the first embodiment, the maximum value of the second distance may be about 9.4 times the minimum value.

[0206] The optical system 1000 according to the first embodiment can satisfy at least one of the mathematical expressions described below. Therefore, the optical system 1000 according to the first embodiment can prevent or minimize changes in optical characteristics according to temperature in the temperature range from low temperature to high temperature, thereby achieving improved optical characteristics at various temperatures. In addition, the optical system 1000 according to the embodiment can have improved distortion and aberration characteristics at various temperatures by satisfying at least one of the mathematical expressions described below. Terms expressed in some mathematical expressions will be referred to Figure 21 Provide a description.

[0207] [Mathematical expression 1]

[0208] 1.2 <L1_CT / L1_ET<1.5

[0209] In Mathematical Expression 1, L1_CT is the thickness (mm) at the center of the first lens 101 and the thickness of the first lens 101 at the optical axis OA at room temperature (approximately 20° C.), and L1_ET means the thickness (mm) of the end portion of the effective area of ​​the first lens 101 in the optical axis OA direction at room temperature (approximately 20° C.). When the optical system 1000 according to the embodiment satisfies Mathematical Expression 1, factors affecting the field of view of the optical system 1000 may be set, and factors affecting the effective focal length (EFL) may be set. In the first embodiment, Mathematical Expression 1 may preferably satisfy 1.3 <L1_CT / L1_ET<1.4。

[0210] [Mathematical expression 2]

[0211] 1 <L2_CT / L2_ET<1.5

[0212] In Mathematical Expression 2, L2_CT is the thickness (mm) at the center of the second lens 102 at room temperature (approximately 20° C.) and the thickness of the second lens 102 at the optical axis OA. In addition, L2_ET means the thickness (mm) of the end portion of the effective area of ​​the second lens 101 in the optical axis OA direction at room temperature (approximately 20° C.). L1_ET may be the thickness of the flange portion outside the clear aperture of the first lens 101. When the optical system 1000 according to the embodiment satisfies Mathematical Expression 2, the optical system 1000 may have improved chromatic aberration reduction characteristics. In the first embodiment, Mathematical Expression 2 may preferably satisfy 1 <L2_CT / L2_ET<1.2。

[0213] [Mathematical expression 3]

[0214] 0.5 <L3_CT / L3_ET<1

[0215] In Mathematical Expression 3, L3_CT is the thickness (mm) at the center of the third lens 103 at room temperature (approximately 20°C) and the thickness of the third lens at the optical axis OA. In addition, L3_ET means the thickness (mm) of the end of the effective area of ​​the third lens 103 in the direction of the optical axis OA at room temperature (approximately 20°C). L3_ET may be the thickness of the flange portion outside the clear aperture of the third lens (103). When the optical system 1000 according to the embodiment satisfies Mathematical Expression 3, the optical system 1000 may have improved aberration reduction characteristics. In the first embodiment, Mathematical Expression 3 may preferably satisfy 0.8 <L3_CT / L3_ET<1。

[0216] [Mathematical expression 4]

[0217] 1.6 <n1<1.7

[0218] In Mathematical Expression 4, n1 is the refractive index of light of the d-line (587.6 nm) wavelength band of the first lens 101. If Mathematical Expression 4 is satisfied, the refractive performance of the first lens 101 disposed closest to the object side in the optical system 1000 can be ensured. In the first embodiment, Mathematical Expression 4 can preferably satisfy 1.62 <n1<1.66。

[0219] [Mathematical expression 5]

[0220] 20 <v1<30

[0221] In Mathematical Expression 5, v1 means the Abbe number of the first lens 101. If Mathematical Expression 5 is satisfied, the refractive performance of the first lens 101 disposed closest to the object side in the optical system 1000 can be ensured. In the first embodiment, Mathematical Expression 5 may preferably satisfy 22 <v1<27。

[0222] [Mathematical expression 6]

[0223] 1.6 <n2<1.7

[0224] In Mathematical Expression 6, n2 is the refractive index of light of the d-line (587.6 nm) wavelength band of the second lens 102. When Mathematical Expression 6 is satisfied, the refractive performance of the second lens 102 disposed closest to the object side in the optical system 1000 can be ensured. In the first embodiment, Mathematical Expression 6 can preferably satisfy 1.62 <n2<1.66。

[0225] [Mathematical expression 7]

[0226] 1.2 <L3S2_max_sag to Sensor<1.5

[0227] In Mathematical Expression 7, L3S2_max_sag to Sensor means the distance (mm) from the point of maximum sag value on the sensor side (sixth surface S6) of the third lens 103 to the image sensor 600 along the optical axis OA direction. When Mathematical Expression 7 is satisfied, the size of the camera module including the optical system 1000 can be minimized. In the first embodiment, Mathematical Expression 7 may preferably satisfy 1.3 <L3S2_max_sag to Sensor<1.4。

[0228] [Mathematical expression 8]

[0229] 1 <BFL / L3S2_max_sag to Sensor<1.5

[0230] In Mathematical Expression 8, L3S2_max_sag to Sensor means the distance (mm) from the point of maximum sag value on the sensor side (sixth surface S6) of the third lens 103 to the image sensor 600 along the optical axis OA. BFL (back focal length) is the distance (mm) from the sensor-side vertex of the lens closest to the image sensor 600 to the upper surface of the image sensor 600 on the optical axis OA at room temperature (approximately 20° C.). When Mathematical Expression 8 is satisfied, the size of the camera module including the optical system 1000 can be minimized. In the first embodiment, Mathematical Expression 8 may preferably satisfy 1 <BFL / L3S2_max_sag to Sensor<1.3。

[0231] [Mathematical expression 9]

[0232] 30<|L3S2_max slope|<35

[0233] In Mathematical Expression 9, the L3S2_max slope angle refers to the maximum angle between a tangent line on the sensor side of the third lens 103 and a line perpendicular to the optical axis OA. When the optical system 1000 according to an embodiment satisfies Mathematical Expression 9, the optical system 1000 can minimize flare. In the first embodiment, Mathematical Expression 9 preferably satisfies 33<|L3S2_max slope|<35.

[0234] [Mathematical expression 10]

[0235] 7 <d23_max / d23_CT<10

[0236] In Mathematical Expression 10, d23_max means the maximum distance (mm) among the distances from the sensor side (fourth surface S4) of the second lens 102 to the object side (fifth surface S5) of the third lens 103 at room temperature (approximately 20° C.), and d23_CT means the distance (mm) from the sensor side (fourth surface S4) of the second lens 102 to the object side (fifth surface S5) of the third lens 103 on the optical axis OA at room temperature (approximately 20° C.). When the optical system 1000 according to the embodiment satisfies Mathematical Expression 10, the optical system 1000 can have improved peripheral field of view characteristics, chromatic aberration, and distortion characteristics. In the first embodiment, Mathematical Expression 10 can preferably satisfy 9 <d23_max / d23_CT<10。

[0237] [Mathematical expression 11]

[0238] 0.1 <L2_CT / L1_CT<1

[0239] In mathematical expression 11, L2_CT means the center thickness of the second lens 102 in the optical axis OA direction at room temperature (approximately 20°C). In addition, L1_CT means the center thickness of the first lens 101 in the optical axis OA direction at room temperature (approximately 20°C). When mathematical expression 11 is satisfied, factors affecting the field of view of the optical system can be set, and factors affecting the effective focal length (EFL) can be set. In the first embodiment, mathematical expression 11 can preferably satisfy 0.5 <L2_CT / L1_CT<1。

[0240] [Mathematical expression 12]

[0241] 1.2 <L2R1 / L2R2<1.5

[0242] In Mathematical Expression 12, L2R1 is the curvature radius of the object side (third surface S3) of the second lens 102 at room temperature (about 20°C), and L2R2 is the curvature radius of the sensor side (fourth surface S4) of the second lens 102 at room temperature (about 20°C). When the optical system 1000 according to the embodiment satisfies Mathematical Expression 12, the optical system 1000 can have improved aberration control characteristics. In the first embodiment, Mathematical Expression 12 can preferably satisfy 1.3 <L2R1 / L2R2<1.4。

[0243] [Mathematical expression 13]

[0244] 0.1 <CA_L1 / CA_L2<1

[0245] In mathematical expression 13, CA_L1 means the size of the clear aperture of the first lens 101, and CA_L2 means the size of the clear aperture of the second lens 102. The size of the clear aperture of each lens means the average value of the lens on the object side and the sensor side. When mathematical expression 13 is satisfied, degradation of optical characteristics due to temperature changes can be suppressed, and the optical system 1000 can control incident light and set factors that affect aberrations. In the first embodiment, mathematical expression 13 can preferably satisfy 0.5 <CA_L1 / CA_L2<1。

[0246] [Mathematical expression 14]

[0247] 0.5 <CA_L2 / CA_L3<1

[0248] In Mathematical Expression 14, CA_L2 means the size of the clear aperture of the second lens 102, and CA_L3 means the size of the clear aperture of the third lens 103. The size of the clear aperture of each lens means the average value of the lens on the object side and the sensor side. When Mathematical Expression 14 is satisfied, degradation of optical characteristics due to temperature changes can be suppressed, and the optical system 1000 can control incident light and set factors that affect aberrations. In the first embodiment, Mathematical Expression 14 can preferably satisfy 0.5 <CA_L2 / CA_L3<0.7。

[0249] [Mathematical expression 15]

[0250] 1 <L_CT_Max / Air_Max<2

[0251] In mathematical expression 15, L_CT_Max means the value having the largest center thickness in the optical axis OA direction among the first lens 101 to the third lens 103. In addition, Air_Max means the larger value of the distance between the first lens 101 and the second lens 102 and the distance between the second lens 102 and the third lens 103 in the optical axis OA direction. When the optical system 1000 according to the embodiment satisfies mathematical expression 15, the optical system 1000 can have good optical performance and TTL reduction characteristics under the set field of view and focal length. In the first embodiment, mathematical expression 15 can preferably satisfy 1.4 <L_CT_Max / Air_Max<1.7。

[0252] [Mathematical expression 16]

[0253] 3<∑L_CT / ∑Air_CT<3.5

[0254] In Mathematical Expression 16, ∑L_CT refers to the sum of the center thicknesses of the first through third lenses 101, 103 along the optical axis OA. Furthermore, ∑Air_CT refers to the sum of the distances between the first and second lenses 101, 102, and between the second and third lenses 102, 103, along the optical axis OA. When the optical system 1000 according to an embodiment satisfies Mathematical Expression 16, it can achieve excellent optical performance and TTL reduction characteristics at a given field of view and focal length. In the first embodiment, Mathematical Expression 16 preferably satisfies 3<∑L_CT / ∑Air_CT<3.2.

[0255] [Mathematical expression 17]

[0256] 10∑Abb / ∑Index<15

[0257] In Mathematical Expression 17, ∑Index refers to the sum of the refractive indices of the first through third lenses 101 through 103 at each d-line at room temperature (approximately 20°C). Additionally, ∑Abb refers to the sum of the Abbe numbers of the first through third lenses 101 through 103 at room temperature (approximately 20°C). When the optical system 1000 according to an embodiment satisfies Mathematical Expression 17, the optical system 1000 can have improved aberration characteristics and resolution. In the first embodiment, Mathematical Expression 17 preferably satisfies 13<∑Abb / ∑Index<15.

[0258] [Mathematical expression 18]

[0259] 1 <CA_L1S1 / CA_min<1.5

[0260] In Mathematical Expression 18, CA_L1S1 is the size of the clear aperture on the object side S1 of the first lens 101, and CA_min is the size of the clear aperture (CA) of the lens surface having the smallest clear aperture (CA) size among the lens surfaces of the plurality of lenses 101 to 103 included in the optical system 1000 at room temperature (approximately 20° C.). When the optical system 1000 according to the embodiment satisfies Mathematical Expression 18, the optical system 1000 can have structural characteristics of optical performance and TTL reduction. In the first embodiment, Mathematical Expression 18 can preferably satisfy 1 <CA_L1S1 / CA_min<1.2。

[0261] [Mathematical expression 19]

[0262] 1.5 <CA_max / CA_min<2

[0263] In Mathematical Expression 19, CA_max is the size of the clear aperture (CA) of the lens surface having the largest clear aperture (CA) size among the lens surfaces of the plurality of lenses 101 to 103 included in the optical system 1000 at room temperature (approximately 20°C). In addition, CA_min is the size of the clear aperture (CA) of the lens surface having the smallest clear aperture (CA) size among the lens surfaces of the plurality of lenses 101 to 103 included in the optical system 1000 at room temperature (approximately 20°C). When the optical system 1000 according to the embodiment satisfies Mathematical Expression 19, the optical system 1000 can have optical performance and structural characteristics of TTL reduction. In the first embodiment, Mathematical Expression 19 can preferably satisfy 1.5 <CA_max / CA_min<1.8。

[0264] [Mathematical expression 20]

[0265] 1 <CA_max / CA_Aver<1.5

[0266] In mathematical expression 20, CA_max is the size of the clear aperture (CA) of the lens surface having the largest clear aperture (CA) size among the lens surfaces of the plurality of lenses 101 to 103 included in the optical system 1000 at room temperature (approximately 20°C). In addition, CA_Aver means the average value (mm) of the clear aperture (CA) sizes of the lens surfaces (object side, sensor side) of the plurality of lenses 101 to 103 included in the optical system 1000 at room temperature (approximately 20°C). When the optical system 1000 according to the embodiment satisfies mathematical expression 20, the optical system 1000 can have optical performance and structural characteristics of TTL reduction. In the first embodiment, mathematical expression 20 can preferably satisfy 1.2 <CA_max / CA_Aver<1.5。

[0267] [Mathematical expression 21]

[0268] 0.5 <CA_min / CA_Aver<1

[0269] In Mathematical Expression 21, CA_min is the size of the clear aperture (CA) of the lens surface having the smallest clear aperture (CA) size among the lens surfaces of the plurality of lenses 101 to 103 included in the optical system 1000 at room temperature (approximately 20°C). In addition, CA_Aver means the average value (mm) of the clear aperture (CA) sizes of the lens surfaces (object side, sensor side) of the plurality of lenses 101 to 103 included in the optical system 1000 at room temperature (approximately 20°C). When the optical system 1000 according to the embodiment satisfies Mathematical Expression 21, the optical system 1000 can be provided in a slim and compact structure, and can have an appropriate size for achieving optical performance in a temperature range from low temperature to high temperature. In the first embodiment, Mathematical Expression 21 can preferably satisfy 0.5 <CA_min / CA_Aver<0.8。

[0270] [Mathematical expression 22]

[0271] 0.5 <CA_max / (2*ImgH)<1

[0272] In mathematical expression 22, CA_max is the size of the clear aperture (CA) of the lens surface having the largest clear aperture (CA) size among the lens surfaces of the plurality of lenses 101 to 103 included in the optical system 1000 at room temperature (approximately 20°C). In addition, ImgH is the value of the vertical distance from the 0 field area of ​​the image sensor 600 overlapping with the optical axis OA to the 1.0 field area of ​​the image sensor 600 at room temperature (approximately 20°C). In other words, ImgH means 1 / 2 of the total diagonal length (mm) of the image sensor 600 at room temperature (approximately 20°C). When the optical system 1000 according to the embodiment satisfies mathematical expression 22, the optical system 1000 can be provided in a slim and compact structure, and can have an appropriate size for achieving optical performance in a temperature range from low temperature to high temperature. In the first embodiment, mathematical expression 22 can preferably satisfy 0.5 <CA_max / (2*ImgH)<0.8。

[0273] [Mathematical expression 23]

[0274] 1.4 <f / L1R1<1.8

[0275] In mathematical expression 23, f means the effective focal length (mm) of the optical system 1000 at room temperature (about 20°C). f may be EFL (effective focal length). In addition, L1R1 is the curvature radius of the object side (first surface S1) of the first lens 101 at room temperature (about 20°C). When the optical system 1000 according to the embodiment satisfies mathematical expression 23, the optical system 1000 may be provided with a TTL reduction structure. In the first embodiment, mathematical expression 23 may preferably satisfy 1.4 <f / L1R1<1.7。

[0276] [Mathematical expression 24]

[0277] 0.5 <EPD / L1R1<1

[0278] In mathematical expression 24, EPD (entrance pupil diameter) means the diameter of the entrance pupil. In addition, L1R1 is the curvature radius of the object side (first surface S1) of the first lens 101 at room temperature (approximately 20°C). When the optical system 1000 according to the embodiment satisfies mathematical expression 24, the optical system 1000 can have incident light control characteristics. In the first embodiment, mathematical expression 24 can preferably satisfy 0.6 <EPD / L1R1<0.8。

[0279] [Mathematical expression 25]

[0280] 0.5 <f1 / f2<1

[0281] In Mathematical Expression 25, f1 is the focal length (mm) of the first lens 101 at room temperature (about 20°C), and f2 is the focal length (mm) of the second lens 102 at room temperature (about 20°C). When the optical system 1000 according to the embodiment satisfies Mathematical Expression 25, the optical system 1000 can have an appropriate refractive power to control the incident light path of the first lens 101 and the second lens 102, and the optical system 1000 can have improved resolution. In the first embodiment, Mathematical Expression 25 can preferably satisfy 0.8 <f1 / f2<1。

[0282] [Mathematical expression 26]

[0283] 5 <TTL<6

[0284] In Mathematical Expression 26, TTL is the distance (mm) from the object side (first surface S1) of the first lens 101 to the upper surface of the image sensor 600 on the optical axis OA at room temperature (approximately 20° C.). If Mathematical Expression 26 is satisfied, a suitable vehicle optical system can be provided. In the first embodiment, Mathematical Expression 26 can preferably satisfy 5 <TTL<5.5。

[0285] [Mathematical expression 27]

[0286] 2 <ImgH<3

[0287] In Mathematical Expression 27, ImgH is the value of the vertical distance from the 0 field area at the center of the upper surface of the image sensor 600 overlapping the optical axis OA to the 1.0 field area of ​​the image sensor 600 at room temperature (approximately 20°C). In other words, ImgH means 1 / 2 of the total diagonal length (mm) of the image sensor 600 at room temperature (approximately 20°C). If Mathematical Expression 27 is satisfied, an optical system having a vehicle sensor size can be provided. In the first embodiment, Mathematical Expression 27 may preferably satisfy 2 <ImgH<2.5。

[0288] [Mathematical expression 28]

[0289] 1.2 <BFL<1.8

[0290] In mathematical expression 28, BFL (back focal length) is the distance (mm) from the vertex on the sensor side of the lens closest to the image sensor 600 to the upper surface of the image sensor 600 on the optical axis OA at room temperature (about 20°C). If mathematical expression 28 is satisfied, the installation space for the filter 500 and the cover glass can be ensured, and the assembly of the components can be improved by the distance between the image sensor 400 and the last lens, and the coupling reliability can be improved. If the BFL is less than the range of mathematical expression 28, some of the light traveling to the image sensor may not be transmitted to the image sensor, which may result in reduced resolution. If the BFL exceeds the range of mathematical expression 28, stray light may be introduced, which may deteriorate the aberration characteristics of the optical system. In the first embodiment, mathematical expression 28 may preferably satisfy 1.3 <BFL<1.6。

[0291] [Mathematical expression 29]

[0292] 3 <f<4

[0293] In Mathematical Expression 29, f means the effective focal length (mm) of the optical system 1000 at room temperature (approximately 20° C.). F may be the effective focal length (EFL). If Mathematical Expression 29 is satisfied, a focal length suitable for the vehicle optical system may be set. In the first embodiment, Mathematical Expression 29 may preferably satisfy 3.5 <f<4。

[0294] [Mathematical expression 30]

[0295] 50 <FOV<70

[0296] In mathematical expression 30, FOV means the field of view (FOV) of the optical system 1000 in an environment of room temperature (about 20°C), low temperature (about -40°C), and high temperature (about 85°C). If mathematical expression 30 is satisfied, a field of view suitable for a vehicle optical system can be provided. In the first embodiment, mathematical expression 30 can preferably satisfy 60 <FOV<70。

[0297] [Mathematical expression 31]

[0298] 1.2 <TTL / CA_max<1.8

[0299] In mathematical expression 31, TTL is the distance (mm) from the object side (first surface S1) of the first lens 101 to the upper surface of the image sensor 600 on the optical axis OA in an environment of room temperature (approximately 20°C). In addition, CA_max is the size (CA) of the clear aperture of the lens surface having the largest clear aperture (CA) size among the lens surfaces of the plurality of lenses 101 to 103 included in the optical system 1000 at room temperature (approximately 20°C). When the optical system 1000 according to the embodiment satisfies mathematical expression 31, the optical system 1000 has good optical performance at the center and periphery of the field of view (FOV) and can be provided in a slim and compact structure. In the first embodiment, mathematical expression 31 may preferably satisfy 1.4 <TTL / CA_max<1.7。

[0300] [Mathematical expression 32]

[0301] 2 <TTL / ImgH<2.5

[0302] In mathematical expression 32, TTL is the distance (mm) from the object side (first surface S1) of the first lens 101 to the upper surface of the image sensor 600 on the optical axis OA in an environment of room temperature (approximately 20°C). In addition, ImgH is the value of the perpendicular distance from the 0 field area at the center of the upper surface of the image sensor 600 overlapping with the optical axis OA to the 1.0 field area of ​​the image sensor 600 at room temperature (approximately 20°C). In other words, ImgH means 1 / 2 of the total diagonal length (mm) of the image sensor 600 at room temperature (approximately 20°C). When the optical system 1000 according to the embodiment satisfies mathematical expression 32, the optical system 1000 can ensure the BFL (back focal length) for applying a relatively large-sized image sensor 600, such as a large image sensor 600 of about 1 inch, and can have a smaller TTL, thereby achieving high quality and having a slim structure. In the first embodiment, mathematical expression 32 can preferably satisfy 2.3 <TTL / ImgH<2.5。

[0303] [Mathematical expression 33]

[0304] 0.2 <BFL / ImgH<0.7

[0305] In mathematical expression 33, BFL (back focal length) is the distance (mm) from the vertex on the sensor side of the lens closest to the image sensor 600 to the upper surface of the image sensor 600 on the optical axis OA at room temperature (approximately 20°C). In addition, ImgH is the value of the vertical distance from the 0 field area at the center of the upper surface of the image sensor 600 overlapping with the optical axis OA to the 1.0 field area of ​​the image sensor 600 at room temperature (approximately 20°C). In other words, ImgH means 1 / 2 of the total diagonal length (mm) of the image sensor 600 at room temperature (approximately 20°C). When the optical system 1000 according to the embodiment satisfies mathematical expression 33, the optical system 1000 can ensure the BFL (back focal length) for applying a relatively large image sensor 600, such as a large image sensor 600 of about 1 inch, and can minimize the distance between the last lens and the image sensor 600 so that it can have good optical characteristics at the center and periphery of the field of view (FOV). In the first embodiment, preferably, mathematical expression 33 can satisfy 0.5 <BFL / ImgH<0.7。

[0306] [Mathematical expression 34]

[0307] 3 <TTL / BFL<4

[0308] In mathematical expression 34, TTL is the distance (mm) from the object side (first surface S1) of the first lens 101 to the upper surface of the image sensor 600 on the optical axis OA in an environment at room temperature (about 20°C). In addition, BFL (back focal length) is the distance (mm) from the top of the sensor side of the lens closest to the image sensor 600 to the upper surface of the image sensor 600 on the optical axis OA at room temperature (about 20°C). When the optical system 1000 according to the embodiment satisfies mathematical expression 34, the optical system 1000 can be set to be slim and compact while ensuring BFL. In the first embodiment, preferably, mathematical expression 34 can satisfy 3.2 <TTL / BFL<3.5。

[0309] [Mathematical expression 35]

[0310] 0.5 <f / TTL<1

[0311] In mathematical expression 35, f means the effective focal length (mm) of the optical system 1000 at room temperature (about 20°C). F may be EFL (effective focal length). In addition, TTL is the distance (mm) from the object side (first surface S1) of the first lens 101 to the upper surface of the image sensor 600 on the optical axis OA in a room temperature (about 20°C) environment. When the optical system 1000 according to the embodiment satisfies mathematical expression 35, the optical system 1000 can be set in a slim and compact manner. In the first embodiment, preferably, mathematical expression 35 can satisfy 0.6 <f / TTL<0.8。

[0312] [Mathematical expression 36]

[0313] 2 <f / BFL<2.5

[0314] In mathematical expression 36, f means the effective focal length (mm) of the optical system 1000 at room temperature (about 20°C). f may be EFL (effective focal length). In addition, BFL (back focal length) is the distance (mm) from the vertex on the sensor side of the lens closest to the image sensor 600 to the upper surface of the image sensor 600 on the optical axis OA at room temperature (about 20°C). When the optical system 1000 according to the embodiment satisfies mathematical expression 36, the optical system 1000 can have a set field of view and an appropriate focal length, and can be provided in a slim and compact manner. In addition, the optical system 1000 can minimize the distance between the last lens and the image sensor 600, so that it can have good optical characteristics in the periphery of the field of view (FOV). In the first embodiment, preferably, mathematical expression 36 can satisfy 2.3 <f / BFL<2.5。

[0315] [Mathematical expression 37]

[0316] 1.3 <f / ImgH<1.8

[0317] In mathematical expression 37, f means the effective focal length (mm) of the optical system 1000 at room temperature (about 20°C). F may be EFL (effective focal length). In addition, ImgH is the value of the perpendicular distance from the 0 field area of ​​the image sensor 600 overlapping with the optical axis OA to the 1.0 field area of ​​the image sensor 600 at room temperature (about 20°C). In other words, ImgH means 1 / 2 of the total diagonal length (mm) of the image sensor 600 at room temperature (about 20°C). When the optical system 1000 according to the embodiment satisfies mathematical expression 37, the optical system 1000 can apply a relatively large-sized image sensor 600, for example, a large image sensor 600 of about 1 inch, and can have improved aberration characteristics. In the first embodiment, preferably, mathematical expression 37 can satisfy 1.5 <f / ImgH<1.7。

[0318] [Mathematical expression 38]

[0319] 2 <f / EPD<2.3

[0320] In mathematical expression 38, f means the effective focal length (mm) of the optical system 1000 at room temperature (about 20° C.). F may be EFL (effective focal length). In addition, EPD (entrance pupil diameter) means the diameter of the entrance pupil. In the first embodiment, preferably, mathematical expression 38 may satisfy 2 <f / EPD<2.1。

[0321] [Mathematical expression 39]

[0322] 1.8 <Fno<2.2

[0323] In Mathematical Expression 39, Fno means the F number of the optical system. When the optical system 1000 according to the embodiment satisfies Mathematical Expression 39, it can take pictures in a dark environment as well as a bright environment, and in particular, it can detect near infrared rays. In the first embodiment, preferably, Mathematical Expression 38 can satisfy 1.9 <Fno<2.1。

[0324] [Mathematical expression 40]

[0325]

[0326] In mathematical expression 40, Z may 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. Additionally, Y may refer to the distance from any position on the aspherical surface to the optical axis in a direction perpendicular to the optical axis. Additionally, c may refer to the curvature of the lens, and K may refer to the conic constant. Furthermore, A, B, C, D, ... may represent aspherical coefficients.

[0327] In other words, in the optical system 1000 according to the embodiment, the first lens 101, the second lens 102, and the third lens 103 can be provided with the same material and can satisfy at least one of the above-mentioned mathematical expressions 1 to 39. Therefore, the optical system 1000 can prevent or minimize the change in optical characteristics according to temperature and can have improved optical characteristics at various temperatures.

[0328] In addition, the optical system 1000 according to the embodiment can prevent or minimize changes in distortion and aberration characteristics at various temperatures by satisfying at least one of Mathematical Expressions 1 to 39, thereby having improved optical characteristics.

[0329] Table 14 below shows items of the above mathematical expressions in the optical system 1000 according to the first embodiment, such as the focal lengths of the first lens 101 to the third lens 103 at room temperature (approximately 20° C.), the TTL (total track length), the BFL (back focal length), the F value, the ImgH, and the effective focal length (EFL) value of the optical system 1000 according to the temperature.

[0330] Table 15 shows result values ​​of the above-described mathematical expressions 1 to 39 in the optical system 1000 according to the first embodiment.

[0331] [Table 14]

[0332]

[0333]

[0334] [Table 15]

[0335]

[0336]

[0337]

[0338] Referring to Table 15, it can be seen that the optical system 1000 according to the first embodiment satisfies at least one of Mathematical Expressions 1 to 39. In detail, it can be seen that the optical system 1000 according to the first embodiment satisfies all of Mathematical Expressions 1 to 39.

[0339] Therefore, the optical system 1000 according to the first embodiment has a field of view of about 60 degrees (60±1 degrees) in a temperature range from low temperature (-40°C) to high temperature (85°C), and can have a field of view of about 60 degrees (60±1 degrees). Figures 5 to 13 Optical properties shown.

[0340] Figures 5 to 13Graphs showing the diffraction MTF characteristics and aberrations of the optical system 1000 according to temperature.

[0341] In detail, Figure 5 is a graph of the diffraction MTF characteristics of the optical system 1000 in a low temperature (-40°C) environment, and Figure 6 Graph showing the diffraction MTF characteristics of the optical system 1000 in which the peak standard is compensated according to actuator driving in a low temperature (-40° C.) environment. Figure 8 is a graph of the diffraction MTF characteristics of the optical system 1000 at room temperature (20°C), and Figure 9 Graph showing the diffraction MTF characteristics of the optical system 1000 in which the peak standard is compensated according to actuator driving in a room temperature (20° C.) environment. Figure 11 is a graph of the diffraction MTF characteristics of the optical system 1000 in a high temperature (85°C) environment, and Figure 12 is a graph of diffraction MTF characteristics of the optical system 1000 in which the peak reference is compensated according to the actuator operation under a high temperature (85° C.) environment.

[0342] in addition, Figure 7 、 Figure 10 and Figure 13 The graphs are respectively the aberrations of the optical system 1000 under low temperature (-40°C), room temperature (20°C) and high temperature (85°C) environments, wherein the spherical aberration (longitudinal spherical aberration), astigmatism field curve and distortion are measured from left to right. Figure 7 、 Figure 10 and Figure 13 In the graph, the X-axis may represent focal length (mm) or distortion (%), and the Y-axis may represent image height. Furthermore, the graph for spherical aberration is for light in the wavelength bands of approximately 920 nm, approximately 940 nm, and approximately 960 nm, and the graphs for astigmatism and distortion are for light in the wavelength band of 940 nm.

[0343] exist Figure 7 、 Figure 10 and Figure 13 In the aberration diagram, the closer each curve is to the Y axis, the better it can explain the aberration correction function, and refer to Figure 7 、 Figure 10 and Figure 13 , it can be seen that the optical system 1000 according to the first embodiment has measurement values ​​close to the Y axis in almost all areas.

[0344] Reference Figures 5 to 13, it can be seen that even when the temperature changes within a range from low temperature (-40°C) to high temperature (85°C), the optical system 1000 according to the first embodiment has little or no change in MTF characteristics and aberration characteristics. In detail, it can be seen that the change in the MTF characteristics at low temperature (-40°C) and high temperature (85°C) is less than 10% of the MTF characteristics at room temperature (22°C).

[0345] In other words, the optical system 1000 according to the first embodiment can maintain excellent optical characteristics in various temperature ranges. In detail, the optical system 1000 may include the same plastic material as the first lens 101 , the second lens 102 , and the third lens 103 .

[0346] At this time, the first lens 101 to the third lens 103 according to the first embodiment are provided with set refractive index, shape, thickness, etc. so that they can mutually compensate for the focal length change caused by the change in refractive index that changes according to temperature. Therefore, the optical system 1000 can prevent or minimize the change in optical characteristics within the temperature range of low temperature (-40°C) to high temperature (85°C), and can maintain improved optical characteristics.

[0347] like Figure 14 、 Figure 26 and Figure 38 As shown, the optical systems 1100, 1200, and 1300 according to the second to fourth embodiments of the present disclosure may include five or more lenses. The optical systems 1100, 1200, and 1300 and camera modules incorporating these optical systems 1100, 1200, and 1300 can be installed inside or outside a vehicle to monitor the driver or sense external objects or lanes. The lens material can be selected from glass or plastic, with the linear expansion coefficient of glass being smaller than that of plastic. Therefore, glass lenses are used to suppress changes in the focal imaging position due to temperature changes. However, compared to plastic lenses, glass lenses are expensive and struggle to meet low-cost requirements. Therefore, the lenses in the optical systems 1100, 1200, and 1300 need to have a hybrid configuration of glass and plastic lenses. By employing these plastic lenses, the optical systems 1100, 1200, and 1300 can achieve weight reduction and cost reduction, as the thickness of the plastic lenses can be reduced and various aberrations, such as spherical aberration and chromatic aberration, can be effectively corrected. In addition, since the plastic lens can provide an aspherical lens, the distortion portion of the peripheral portion can be minimized.

[0348] Optical systems 1100, 1200, and 1300 may include n lenses, wherein the n-th lens may be the last lens adjacent to image sensor 600, and the (n-1)-th lens may be the lens closest to the last lens. n is an integer greater than or equal to 5, for example, 5 to 8. The ratio of glass lenses to plastic lenses in the n lenses may be in the range of 2:4 to 3:4.

[0349] At least one lens closest to the subject in optical systems 1100, 1200, and 1300 can be made of a glass material. Two or fewer lenses (e.g., one lens) closest to the subject can be made of glass. Because the rate of contraction and expansion of a glass lens due to temperature changes is lower than the rate of contraction and expansion of a plastic lens due to temperature changes, the glass lens can be placed in an area near the outside of the lens barrel.

[0350] At least one lens closest to image sensor 600 in optical systems 1100, 1200, and 1300 may be made of plastic. For example, at least two lenses closest to image sensor 600 may be made of plastic, and preferably, at least two lenses adjacent to image sensor 600 may be made of plastic. In other words, since the nth lens and the (n-1)th lens in optical systems 1100, 1200, and 1300 are arranged as plastic lenses, various aberrations can be corrected for incident light from image sensor 600.

[0351] In optical systems 1100, 1200, and 1300, plastic lenses may be arranged in sequence, and glass lenses may be arranged in sequence. In optical systems 1100, 1200, and 1300, plastic lenses may be arranged between glass lenses. In optical systems 1100, 1200, and 1300, glass lenses may be placed between plastic lenses.

[0352] Each lens 201 to 206, 301 to 306, 401 to 406 can have an object side and a sensor side. The optical system can have a greater number of lenses with aspherical sensor and object sides than plastic lenses. The optical system can have a smaller number of lenses with spherical sensor and object sides than lenses with both sides aspherical. Since the optical systems 1100, 1200, and 1300 have more aspherical lenses than spherical lenses, various aberrations can be corrected.

[0353] Among the lenses of optical systems 1100, 1200, and 1300, the lens with the highest refractive index can be positioned adjacent to the object. The maximum refractive index can be 1.8 or higher. This enhances the dispersion of light incident on the lens with the highest refractive index, and allows the center thickness to be made thinner than the edge thickness. Furthermore, since the lens with the highest refractive index is positioned toward the object, it is easy to change the radius of curvature of the second and subsequent lenses, and the center thickness can be increased.

[0354] In optical systems 1100, 1200, and 1300, the lens with the largest clear aperture can be positioned in the center of the object and sensor sides. The clear aperture of the lens can increase and then decrease as it moves from the object side to the sensor side. The clear aperture of the lens can decrease, then increase, and then decrease again as it moves from the object side to the sensor side. In this way, since light incident on optical systems 1100, 1200, and 1300 is configured to move away from the optical axis and then converge onto it, optical systems 1100, 1200, and 1300 can form a stable optical path.

[0355] The clear aperture may be the diameter of the effective area where effective light enters each lens. The clear aperture is the length in the direction (X, Y) orthogonal to the optical axis, and is the average of the clear aperture on the object side and the clear aperture on the sensor side of each lens. "The diameter of the lens surface" may mean "the clear aperture of the lens." "The diameter of the lens" may be the diameter of the entire lens including the flange portion of the lens in addition to the effective area of ​​the lens. Although Figure 14 、 Figure 26 and Figure 38 The flange of the lens is not shown in the figure, but the flange can be a portion protruding from the side of the lens perpendicular to the optical axis to couple the lens to the lens barrel. The flange is not affected by the effective light. Spacers can be additionally arranged between the flanges of different lenses to couple the lenses to the lens barrel.

[0356] Each of lenses 201 to 206, 301 to 306, and 401 to 406 may include an active region and an inactive region. The active region may be the region through which light incident on each lens passes. In other words, the active region may be defined as the effective area or clear aperture where incident light is refracted to achieve the optical properties. The inactive region may be arranged around the active region. The inactive region may be the region where effective light does not enter the plurality of lenses. In other words, the inactive region may be an area unrelated to the optical properties. Furthermore, the ends of the inactive region may be regions fixed to, for example, a lens barrel that houses the lenses.

[0357] In the optical systems 1100, 1200, 1300, the TTL (total top length) can be more than 1.5 times of Imgh, for example, greater than 1.7 times and less than 2.5 times. TTL (total track length) is the distance from the center of the object side of the first lens to the upper surface of the image sensor 600 on the optical axis OA. Imgh is 1 / 2 of the maximum diagonal length of the image sensor 600. In the optical systems 1100, 1200, 1300, the effective focal length (EFL) is set to 2 mm or greater, and the field of view (FOV) is set to 145 degrees or greater and less than 160 degrees, so that the vehicle camera module can be set as an optical system for monitoring the interior of a vehicle. For example, the optical system and the camera module according to the embodiment can be applied to a camera of an ADAS (advanced driver assistance system) installed inside or outside a vehicle.

[0358] The optical systems 1100, 1200, and 1300 may have a TTL / Imgh of 1.5 or more and 2.5 or less, for example, 1.7 or more and 2 or less. By setting the TTL / Imgh value to 1.5 or more and 2.5 or less, the optical systems 1100, 1200, and 1300 can provide a vehicle lens optical system, and thus, the optical systems 1100, 1200, and 1300 can provide an image without exaggeration or distortion.

[0359] The clear aperture of at least one plastic lens in optical systems 1100, 1200, or 1300 can be smaller than the length of image sensor 600. The clear aperture is the diameter or length of the active area into which light is incident. The length of image sensor 600 is the maximum length of a diagonal line perpendicular to optical axis OA. The number of lenses in optical systems 1100, 1200, or 1300 with a clear aperture greater than the length of image sensor 600 can be 50% or greater, or 60% or greater, and the number of lenses with a clear aperture less than the length of image sensor 600 can be less than 50% or less than 40%. This allows light to be efficiently guided to image sensor 600 while maintaining a TTL below a specific value. This maximizes light efficiency while achieving miniaturization.

[0360] The lens portion can be a mix of glass and plastic lenses. The number of plastic lenses can be 60% or more of the total number of lenses, and can range from 40% to 85% or 60% to 80%. Therefore, when more plastic lenses are arranged in the camera module, the weight of the camera module can be reduced. Plastic materials are easy to polish and process, resist external impacts, are highly price-competitive, and are readily available. Furthermore, plastic lenses can correct various aberrations, thereby preventing degradation of optical performance.

[0361] The embodiments of the present disclosure can reduce the weight of the camera device module by further mixing plastic lenses into the optical systems 1100, 1200, and 1300, can provide lower manufacturing costs, can suppress the degradation of optical properties caused by temperature changes, various types of plastic lenses can replace glass lenses, and can facilitate the polishing and processing of lens surfaces such as aspheric surfaces or free-form surfaces.

[0362] The lens portion may include a lens of a first material and a lens of a second material arranged along the optical axis OA. The first material may be a glass material, and the second material may be a plastic material. The lens of the first material may be arranged between the lenses of the second material. The lens of the second material may be arranged between the lenses of the first material.

[0363] The lens portion may include a lens of a first material having an aspherical surface, a lens of the first material having a spherical surface, and a lens of a second material having an aspherical surface along the optical axis OA. The first material may be a glass material, and the second material may be a plastic material. The lens of the first material having a spherical surface may be arranged between the lens of the second material having an aspherical surface. The lens of the second material may be arranged between the lens of the first material having an aspherical surface and the lens of the first material having a spherical surface.

[0364] The clear aperture of the lens closest to the object within the lens section can be larger than the clear aperture of the lens closest to image sensor 600. Thus, the brightness of the optical system can be controlled. The clear aperture can be the average of the clear apertures on the object and sensor sides of each lens. By controlling the clear aperture size of each lens, optical systems 1100, 1200, and 1300 can control incident light to compensate for degradation of optical characteristics due to resolution and temperature changes, improve chromatic aberration control characteristics, and improve vignetting characteristics of optical systems 1100, 1200, and 1300.

[0365] The lens portion may include a first lens 201, 301, 401, a second lens 102, 202, 302, a third lens 103, 203, 303, a fourth lens 104, 204, 304, a fifth lens 105, 205, 305, a sixth lens 106, 206, 306 and a seventh lens 107, 207, aligned along the optical axis from the object side toward the sensor side.

[0366] In the lens portion, when the focal length is an absolute value, the focal length of the lens closest to the object can be greater than the focal length of the plastic lens. Here, the plastic lens can be at least one lens arranged on the sensor side of the cemented lens or at least one lens adjacent to the image sensor.

[0367] The lens portion may be disposed in an imaging device module having an inner lens barrel on one side or the entire inner surface of the lens barrel. The lens portion may be disposed in an imaging device module having a plurality of inner lens barrels around different lenses of the lens barrel. The lens portion may be disposed in an imaging device module having a first inner lens barrel in contact with the outer surface of at least one lens and a second inner lens barrel in contact with the outer surface of at least one lens of the lens barrel. The lens portion may be disposed in an imaging device module having a plurality of inner lens barrels, each inner lens barrel being disposed between the outer surface of at least one or two or more lenses and the lens barrel. The lens portion may be disposed in an imaging device module having a plurality of inner lens barrels made of a material different from that of the lens barrel.

[0368] At least some of the lenses made of glass in the lens portion forming the lens may be disposed in the lens barrel, and at least some of the lenses made of plastic may be disposed in the inner lens barrel disposed within the lens barrel. In this way, the optical systems 1100, 1200, 1300 can maintain the resolution according to temperature changes. The lens portion is disposed in an imaging device module having a heterogeneous lens barrel, thereby minimizing the eccentricity of lenses that expand according to temperature changes, such as plastic lenses. The lens barrel in which the lens portion is disposed has a plurality of inner lens barrels within the lens barrel, thereby maintaining the resolution of the optical system according to temperature changes and suppressing deformation of the lens. Therefore, the light transmission aperture of at least some of the glass material lenses included in the lens portion may be smaller than the light transmission aperture of at least some of the plastic material lenses.

[0369] The number of lenses in the lens portion having a light transmission aperture larger than the average light transmission aperture of the plastic lenses may be at least one, for example, at least two. When the average light transmission aperture of the plastic material lens is PLca_Aver and the average light transmission aperture of the glass material lens is GLca_Aver, the condition PLca_Aver < GLca_Aver may be satisfied. Additionally, the condition 1 < GLca_Aver / PLca_Aver < 1.5 may be satisfied. Additionally, the relationship between the length of the image sensor 600 and the average light transmission aperture (PLca_Aver) of the plastic lens may satisfy the condition 1 ≤ PLca_Aver / Imgh < 1.5. Additionally, the relationship between the average light transmission aperture of the glass material and the length of the image sensor 600 may satisfy the condition 1.1 < GLca_Aver / Imgh < 1.5. The difference between the maximum length of the image sensor 600 and the light transmission aperture of the plastic lens may be arranged to be small. Therefore, by disposing a plastic lens having a small light transmission aperture and an aspherical surface adjacent to the image sensor 600, the plastic lens can disperse colors from the center to the periphery of the image sensor 600.

[0370] The average clear aperture of the glass material can be 4 mm or greater, for example, within the range of 4.2 mm to 5 mm. The average clear aperture of the plastic material can be 3 mm or greater, for example, within the range of 3.5 mm to 4 mm. The lens with the smallest clear aperture can be made of plastic, and the lens with the largest clear aperture can be made of glass. The smallest clear aperture within the lens portion can be within the range of 2 mm to 3 mm, and the largest clear aperture can be within the range of 6 mm to 7 mm. The plastic lens is designed to have a smaller clear aperture than the glass lens and is arranged so as not to contact the lens barrel with which the glass lens contacts, thereby minimizing changes in optical performance due to temperature changes. In addition, optical systems 1100, 1200, and 1300 can improve resolution and chromatic aberration control characteristics by controlling incident light, and can also improve the vignetting characteristics of optical systems 1100, 1200, and 1300.

[0371] The optical systems 1100, 1200, and 1300 or the camera module may include an image sensor 600. The image sensor 600 may detect light and convert it into an electrical signal. The image sensor 600 may detect light that has sequentially passed through the lens portion. The image sensor 600 may include a device capable of detecting incident light, such as a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor).

[0372] The optical system 1100, 1200, or 1300 or the camera module may include an optical filter 500. The optical filter 500 may be disposed between the last lens and the image sensor 600. The optical filter 500 may be disposed between the lens closest to the sensor side among the lenses in the lens portion and the image sensor 600. For example, the optical filter 500 may be disposed between the nth lens and the image sensor 600.

[0373] The cover glass is placed between the filter 500 and the image sensor 600, and protects the upper portion of the image sensor 600, and can prevent the reliability of the image sensor 600 from being deteriorated. The cover glass can be removed. The cover glass can be protective glass.

[0374] The optical filter 500 may include an infrared filter or an infrared cut filter (IR cut). The optical filter 500 may pass light of a set wavelength band and filter light of a different wavelength band. When the optical filter 500 includes an infrared filter, it may block radiant heat emitted from external light from being transmitted to the image sensor 600. In addition, the optical filter 500 may transmit visible light and reflect infrared light.

[0375] The optical systems 1100, 1200, and 1300 according to embodiments may include an aperture stop. The aperture can adjust the amount of light incident on the optical systems 1100, 1200, 1200, and 1300. In a lens disposed between an object and an aperture, the clear aperture of the lens surface tends to increase as it moves from the object side to the aperture. In a lens surface disposed between the aperture and a sensor, the clear aperture of the lens surface tends to decrease as it moves from the aperture to the sensor side. The meaning that the clear aperture of the lens surface tends to increase or decrease does not only mean the case where the clear aperture of the lens surface increases or decreases. For example, it also includes the case where the clear aperture of the lens surface increases and then decreases as it moves from the aperture to the sensor.

[0376] In the optical systems 1100, 1200, and 1300 of the second to fourth embodiments, the sum of the refractive indices of the lenses of the lens section can be 9 or greater, for example, within the range of 9.5 to 11, and the average refractive index can be within the range of 1.6 to 1.7. The sum of the Abbe numbers of each lens can be 240 or greater, for example, within the range of 240 to 250, and the average Abbe number can be 45 or less, for example, within the range of 38 to 42. The sum of the center thicknesses of all lenses can be 5 mm or greater, for example, within the range of 6 mm to 8 mm, and the average center thickness can be within the range of 1 mm to 1.5 mm. The sum of the center gaps between the lenses on the optical axis OA can be 4 mm or greater, for example, within the range of 4 mm to 5 mm, and can be smaller than the sum of the center thicknesses of the lenses. Furthermore, the average clear aperture of each lens surface S1 to S14 of the lens section can be set to 3 mm or greater, for example, within the range of 3.5 mm to 4.5 mm.

[0377] In the optical systems according to the second to fourth embodiments of the present disclosure, the F number may be 2.4 or less, for example, in the range of 2 to 2.3. The vehicle optical system may have a horizontal field of view (FOV_H) in the Y-axis direction that is greater than 145 degrees and less than 160 degrees, for example, in the range of 150 to 155 degrees. In addition, the vertical field of view may be set at an angle smaller than the horizontal field of view. Therefore, changes in the focus position due to temperature changes can be suppressed, and a vehicle camera device in which various aberrations are well corrected can be provided.

[0378] Since the embodiments are optical systems for vehicle camera devices, even if a plastic lens and a glass lens are designed together, the first lenses 201, 301, and 401 can be made of glass. This has the advantages of being more scratch-resistant than plastic and less sensitive to external temperatures. The first lenses 201, 301, and 401 can be molded glass lenses having an aspherical surface and made of glass. A molded glass lens can be manufactured by placing an optical glass ingot in a mold having an aspherical surface and then heating and compressing the ingot.

[0379] In order to more effectively prevent scratches caused by foreign objects or objects placed inside the vehicle, a glass lens can be used as the first lens 201, 301, 401, and the object side of the first lens 201, 301, 401 can have a gently curved shape so as not to contact the external structure. This minimizes the occurrence of scratches caused by contact with the external structure. The field of view can be greater than 145 degrees and less than 155 degrees, and for example, can be in the range of 150 degrees to 155 degrees for driver monitoring, front / rear photography of the vehicle, lane detection, and detection of unexpected objects around the vehicle when the vehicle is being driven. This horizontal field of view can be a preset angle for an advanced driver assistance system (ADAS).

[0380] The optical systems 1100, 1200, and 1300 according to the embodiment may further include a reflective member for changing the light path. The reflective member may be implemented as a prism that reflects light incident on the optical systems 1100, 1200, and 1300 toward the lens. Hereinafter, the optical system according to the embodiment will be described in detail.

[0381] An optical system according to a second embodiment of the present disclosure will be described.

[0382] Figure 14 is a side sectional view of an optical system and an image pickup device module having the optical system according to a second embodiment, Figure 15 It shows Figure 14 Table of aspheric coefficients of lenses in optical systems, Figure 16 It shows Figure 14 A table showing the thickness of each lens in an optical system and the distance between adjacent lenses. Figure 17 It shows Figure 14 Table of sag values ​​of the lens surfaces of the first lens to the sixth lens in the optical system, Figure 18 Is to show about Figure 14 The graph of the diffraction MTF (Modulation Transfer Function) data of the optical system at low temperature is shown in FIG. Figure 19 Is to show about Figure 14 A graph showing the aberration characteristics of an optical system at low temperatures. Figure 20 Is to show about Figure 14 A graph of the diffraction MTF data of an optical system at room temperature, Figure 21 Is to show about Figure 14 A graph showing the aberration characteristics of an optical system at room temperature. Figure 22 Is to show about Figure 14 The graph of the diffraction MTF data of the optical system at high temperature is shown in Figure 2. Figure 23 Is to show about Figure 14 A graph showing the aberration characteristics of an optical system at high temperatures. Figure 24 Is to show about Figure 14 A graph showing the diffraction MTF data of the optical system at RGB wavelengths, and Figure 25 Is to show about Figure 14 A graph showing the diffraction MTF data of an optical system at IR wavelengths.

[0383] Reference Figure 14 The optical system 1100 includes a lens portion, and the lens portion may include first to sixth lenses 201 to 206. The first to sixth lenses 201 to 206 may be sequentially arranged along the optical axis OA of the optical system 1100. Light corresponding to information about an object may pass through the first to sixth lenses 201 to 206 and the optical filter 500 and be incident on the image sensor 600.

[0384] The first lens 201 may be positioned closest to the object. The first lens 201 may be positioned furthest from the sensor. The first lens 201 may have negative (-) refractive power along the optical axis OA. The first lens 201 may be made of plastic or glass, and may be, for example, glass. The glass first lens 201 can reduce changes in its center position and radius of curvature due to temperature changes in the surrounding environment, and can protect the incident side of the optical system 1100.

[0385] The first surface S1 on the object side of the first lens 201 based on the optical axis may be convex, and the second surface S2 on the sensor side may be concave. The first lens 201 may have a convex meniscus shape toward the object side. The first lens 201 may be made of glass and have a spherical surface.

[0386] Due to the refractive properties of the first lens 201, the second lens 202 can be further separated from the first lens 201. In other words, the central gap between the first lens 201 and the second lens 202 can be the largest within the lens portion.

[0387] The refractive index n1 of the first lens 201 can satisfy the conditions n1>1.8 or n1>1.82. Since the refractive index n1 of the first lens 201 is the highest among all lenses, the radius of curvature of the first lens 201 and the second lens 202 can be increased, and lens manufacturing can be facilitated. If the refractive index n1 of the first lens 201 is less than this condition, the lens surfaces must be formed into sharp concave or convex shapes to increase the refractive power of the first lens 201 and the second lens 202. In this case, lens manufacturing becomes difficult, the lens defect rate increases, and this leads to a decrease in production yield.

[0388] The second lens 202 may be positioned second from the object side. The second lens 202 may be positioned fifth from the sensor side. The second lens 202 may be positioned between the first lens 201 and the third lens 203. The second lens 202 may have positive (+) refractive power along the optical axis OA. The second lens 202 may be made of plastic or glass. For example, the second lens 202 may be made of plastic.

[0389] The third surface S3 on the object side of the second lens 202 may be concave relative to the optical axis OA, and the fourth surface S4 on the sensor side may be convex. The second lens 202 may have a meniscus shape, in which the sensor side is convex. The second lens 202 may be made of a plastic material and may be aspherical. At least one or both of the third surface S3 and the fourth surface S4 may be aspherical. The aspheric coefficients of the third surface S3 and the fourth surface S4 may be set to Figure 15 At least one or both of the third surface S3 and the fourth surface S4 may be configured to have no critical point from the optical axis OA to the end of the effective area.

[0390] An aperture stop can be arranged around the sensor-side fourth surface S4 of the second lens 202. An aperture stop can be arranged around the object-side fifth surface S5 of the third lens 203. This aperture can reduce the time-to-lose (TTL) within the field of view (FOV), enabling miniaturization of the optical system. This can prevent a decrease in the weight yield of the optical system and improve production efficiency. Furthermore, the optical system can be miniaturized by reducing the TTL within the horizontal field of view (FOV_H) of 130 to 160 degrees.

[0391] The third lens 203 may be positioned third from the object side. The third lens 203 may be positioned fourth from the sensor side. The third lens 203 may be positioned between the second lens 202 and the fourth lens 204. The third lens 203 may have positive (+) refractive power along the optical axis OA. The third lens 203 may be made of plastic or glass. For example, the third lens 203 may be made of glass.

[0392] The fifth surface S5 on the object side of the third lens 203 may be convex relative to the optical axis, and the sixth surface S6 on the sensor side may be convex. The third lens 203 may have a convex shape on both sides. The third lens 203 may be made of glass and may be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 may be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 may be arranged so that there is no critical point from the optical axis OA to the end of the active area.

[0393] Because the third lens 203 has convex sides, the optical system's TTL and number of lenses can be minimized, while efficiently refracting light. Furthermore, when the radius of curvature of the fifth surface S5 of the third lens 203 is L3R1 and the radius of curvature of the sixth surface S6 is L3R2, the condition L3R1 < |L3R2| is satisfied. This allows light to be effectively refracted by the third surface S3, thereby preventing the clear aperture from the fourth lens 204 to the sixth lens 206 from increasing and reducing the TTL. If L3R1 > |L3R2|, significant aberrations may occur on the object side of the third lens 203, reducing the light refraction efficiency on the sensor side, increasing the clear aperture of the rear lens, and potentially increasing the TTL.

[0394] The fourth lens 204 may be positioned fourth from the object side. The fourth lens 204 may be positioned third from the sensor side. The fourth lens 204 may be positioned between the third lens 203 and the fifth lens 205. The fourth lens 204 may have positive (+) or negative (-) refractive power along the optical axis OA. The fourth lens 204 may have negative (-) refractive power. The fourth lens 204 may be made of plastic or glass. For example, the fourth lens 204 may be made of plastic.

[0395] The seventh surface S7 on the object side of the fourth lens 204 may be concave relative to the optical axis, and the eighth surface S8 on the sensor side may be concave. The fourth lens 204 may have a concave shape on both sides. The fourth lens 204 is made of a plastic material and may be aspherical. At least one or both of the seventh surface S7 and the eighth surface S8 may be aspherical. The aspherical coefficients of the seventh surface S7 and the eighth surface S8 may be set to Figure 15 At least one or both of the seventh surface S7 and the eighth surface S8 may be configured to have no critical point from the optical axis OA to the end of the effective area.

[0396] The fifth lens 205 may be positioned fifth from the object side. The fifth lens 205 may be positioned second from the sensor side. The fifth lens 205 may be positioned between the fourth lens 204 and the sixth lens 206. The fifth lens 205 may have positive (+) or negative (-) refractive power along the optical axis OA. The fifth lens 205 may have positive (+) refractive power. The fifth lens 205 may be made of plastic or glass. For example, the fifth lens 205 may be made of plastic.

[0397] Based on the optical axis OA, the fifth lens 205 may have a convex ninth surface S9 on the object side and a convex tenth surface S10 on the sensor side. The fifth lens 205 may have a convex shape on both sides. The fifth lens 205 may be made of a plastic material and may be aspherical. At least one or both of the ninth surface S9 and the tenth surface S10 may be aspherical. The aspherical coefficients of the ninth surface S9 and the tenth surface S10 may be set to Figure 15 At least one or both of the ninth surface S9 and the tenth surface S10 may be provided to have no critical point from the optical axis OA to the end of the effective area.

[0398] The sixth lens 206 may be positioned furthest from the object side. The sixth lens 206 may be positioned closest to the image sensor 600. The sixth lens 206 may have positive (+) or negative (-) refractive power along the optical axis OA. The sixth lens 206 may have negative (-) refractive power. The sixth lens 206 may be made of plastic or glass. For example, the sixth lens 206 may be made of plastic.

[0399] Based on the optical axis OA, the eleventh surface S11 of the sixth lens 206 on the object side may be concave, and the twelfth surface S12 on the sensor side may be convex. The sixth lens 206 may have a meniscus shape with a convex sensor side. At least one or both of the eleventh surface S11 and the twelfth surface S12 may be aspherical. The aspheric coefficients of the eleventh surface S11 and the twelfth surface S12 may be set to Figure 15 At least one or both of the eleventh surface S11 and the twelfth surface S12 may be provided to have no critical point from the optical axis OA to the end of the effective area.

[0400] The sixth lens 206 can be a plastic lens closest to the image sensor 600. In addition, by arranging two or more plastic lenses adjacent to the image sensor 600, aberrations such as spherical aberration and chromatic aberration can be improved by having an aspherical lens surface, and the influence on resolution can be controlled. In addition, by arranging the plastic lens as a lens adjacent to the image sensor 600, the plastic lens can be insensitive to assembly tolerances compared to glass lenses. In other words, being insensitive to assembly tolerances means that even if the components are assembled slightly differently than designed during assembly, the optical performance may not be significantly affected. In addition, by setting the two lenses 205 and 206 adjacent to the image sensor 600 to plastic material, the optical performance can be improved by having an aspherical lens surface, and for example, aberration characteristics can be improved and resolution degradation can be prevented.

[0401] [Table 16]

[0402]

[0403]

[0404] Table 16 shows the surface number (Surface), curvature radius (Radius), center thickness of each lens or distance between lens surfaces (Thickness), refractive index (Index, nd), Abbe number (Abbe, vd), effective radius (Semi Aperture), and focal length (Fcoal length) of the lenses according to the second embodiment of the present disclosure. The units of the curvature radius and thickness or distance may be mm.

[0405] [Table 17]

[0406]

[0407]

[0408] Table 17 shows the terms in the above mathematical expression in the optical system 1100 of the second embodiment, including TTL (total track length) (mm), BFL (back focal length), effective focal length (F) (mm), ImgH (mm), clear aperture (CA) (mm), thickness (mm), TTL (mm), and TD (mm). The above terms are the optical axis distance from the first surface S1 to the twelfth surface S12 of the optical system 1100, the sum of the refractive index, the sum of the Abbe number, the sum of the thickness (mm), the sum of the distances between adjacent lenses, the clear aperture characteristics, the sum of the refractive indices of the glass lenses, the sum of the refractive indices of the plastic materials, the field of view (FOV_H) (degrees), the edge thickness (ET), the F number, etc.

[0409] When the wavelength of light incident on the optical system 1100 changes, focus shift occurs. This phenomenon can be addressed by minimizing focus shift for long wavelengths (IR) and visible light (RGB) through optical design correction. Without design correction for RGB and IR wavelengths, focus shift of approximately 30 μm or greater may occur, potentially failing to maintain optical performance.

[0410] Referring to Table 17, the BFL at the RGB wavelength incident on the optical system 1100 according to the second embodiment is 1.2416um, and the BFL at the IR wavelength is 1.2510(+0.009)um, and the difference between the BFL at the RGB wavelength and the BFL at the IR wavelength is 0.0094um, thereby minimizing the focus shift phenomenon.

[0411] Currently, the application of vehicle surveillance lenses is increasing, and the use of visible light (RGB) and infrared (IR) is emerging as the main performance of vehicle surveillance lenses. During the day, visible light can be used to distinguish colors, while at night, infrared can be used to obtain color images and videos that are as excellent as those during daytime. Therefore, vehicle surveillance lenses should be able to operate stably and achieve high image quality during both daytime and nighttime driving. Optical lenses can be well matched with visible light (RGB) and infrared (IR) chips installed in the vehicle, and can achieve visible light and infrared confocality for dual-use effects during daytime and nighttime.

[0412] The center thicknesses of the first to sixth lenses 201 to 206 are denoted by CT1 to CT6, the edge thicknesses at the ends of the effective regions of each lens are denoted by ET1 to ET6, the center gaps between two adjacent lenses are denoted by CG1 to CG5, and the edge distances between the edges of each lens are denoted by EG1 to EG5. The back focus (BFL) is the optical axis distance from the image sensor 600 to the center of the last lens. The TTL is the optical axis distance from the center of the first surface S1 of the first lens 201 to the top surface of the image sensor 600.

[0413] like Figure 15 As shown, in the lenses of the lens portion of the second embodiment, the lens surfaces of the second lens 202, the fourth lens 204, the fifth lens 205, and the sixth lens 206 may include aspheric surfaces having a 30th-order aspheric coefficient. For example, the second lens 202, the fourth lens 204, the fifth lens 205, and the sixth lens 206 may include lens surfaces having a 30th-order aspheric coefficient. As described above, since an aspheric surface having a 30th-order aspheric coefficient (a non-zero value) can significantly change the aspheric shape of the periphery, optical performance at the periphery of the field of view (FOV) can be well corrected.

[0414] The thicknesses T1 to T6 of the first to sixth lenses 201 to 206 and the distances G1 to G5 between two adjacent lenses may be set. Figure 5 As shown, the thickness T1 to T6 of each lens in the Y-axis direction can be expressed as a distance of 0.1 mm or 0.2 mm or more, and the distance G1 to G5 between each lens can be expressed as a distance of 0.1 mm or 0.2 mm or more.

[0415] When comparing the absolute values ​​of the curvature radii of each lens, the curvature radius of the seventh surface S7 of the fourth lens 204 on the optical axis OA may be the largest among the lenses, and the curvature radius of the eleventh surface S11 of the sixth lens 206 may be the smallest among the lenses. The difference between the maximum curvature radius and the minimum curvature radius may be 5 times or more, for example, 5.5 times to 6 times.

[0416] Since the clear aperture of the plastic lens is smaller than that of the glass lens, the lens placed on the object side of the plastic lens can have a strong refractive power, thereby refracting light using the plastic lens. In addition, the curvature radius of the lens surface can be smaller to enhance the refractive power.

[0417] The absolute value of the radius of curvature of the first surface S1 of the first lens 201 may be greater than the absolute value of the radius of curvature of the second surface S2. The absolute value of the radius of curvature of the third surface S3 of the second lens 202 may be greater than the absolute value of the radius of curvature of the fourth surface S4. The absolute value of the radius of curvature of the fifth surface S5 of the third lens 203 may be greater than the absolute value of the radius of curvature of the sixth surface S6. The absolute value of the radius of curvature of the seventh surface S7 of the fourth lens 204 may be greater than the absolute value of the radius of curvature of the eighth surface S8. The absolute value of the radius of curvature of the ninth surface S9 of the fifth lens 205 may be greater than the absolute value of the radius of curvature of the tenth surface S10. The absolute value of the radius of curvature of the eleventh surface S11 of the sixth lens 206 may be smaller than the absolute value of the radius of curvature of the twelfth surface S12.

[0418] The ratio of the curvature radius of each lens may satisfy the following conditions.

[0419] Condition 1: 3.5 < |L1R1 / L1R2| < 4.5

[0420] Condition 2: 3<|L2R1 / L2R2|<4

[0421] Condition 3: 2<|L3R1 / L3R2|<3

[0422] Condition 4: 3<|L4R1 / L4R2|<4

[0423] Condition 5: 1<|L5R1 / L5R2|<1.5

[0424] Condition 6: 0.1 <L6R1 / L6R2<1

[0425] When describing the center thickness CT of the lens based on the optical axis, the center thickness CT2 of the second lens 202 is the largest among the lenses, and the center thickness CT4 of the fourth lens 204 is the smallest among the lenses. The difference between the maximum center thickness and the minimum center thickness of the lens may be within a range of 2 mm or more and 2.5 mm or less.

[0426] The center thickness of each lens may satisfy any one of the following conditions.

[0427] Condition 1: CT2, CT3, CT5 > CT1 = CT6 > CT4

[0428] Condition 2: CT2>CT1,CT3,CT4,CT5,CT6

[0429] Condition 3: CT2, CT5 > CT3 > CT1, CT4, CT6

[0430] Condition 4: CT1, CT2, CT3, CT5, CT6 > CT4

[0431] Condition 5: CT2>CT5>CT1,CT3,CT4,CT6

[0432] If the center gaps CG between the lenses are described, the center gap CG1 between the first lens 201 and the second lens 202 may be the largest, and the center gap CG3 between the third lens 203 and the fourth lens 204 may be the smallest. The difference between the maximum center gap and the minimum center gap in the lens distance may be 1 mm or more, for example, in the range of 1.5 mm to 2 mm.

[0433] The center gap between each lens can satisfy the following conditions.

[0434] Condition 1: CG1>CG2,CG3,CG4,CG5

[0435] Condition 2: CG1, CG5 > CG2 > CG3, CG4

[0436] Condition 3: CG1, CG2, CG4, CG5 > CG3

[0437] Condition 4: CG1, CG2, CG5 > CG4 > CG3

[0438] Condition 5: CG1>CG5>CG2,CG3,CG4

[0439] In terms of clear aperture, the lens with the largest clear aperture can be positioned between the first lens 201 closest to the subject and the sixth lens 206 closest to the image sensor 600. The lens with the largest clear aperture can be a glass lens. The lens with the largest clear aperture can be the first lens 201. Here, the clear aperture is the average of the clear apertures on the subject side and the sensor side of each lens. The lens surface with the largest clear aperture can be the first surface S1 of the first lens 201.

[0440] The lens with the smallest clear aperture may be a lens disposed between the aperture stop and the image sensor 600. The lens with the smallest clear aperture may be the third lens 203. The lens surface with the smallest clear aperture may be the fifth surface S5 of the third lens 203. The clear aperture of a lens made of plastic may be smaller than the clear aperture of a lens made of glass. The plastic lens may be placed adjacent to the image sensor.

[0441] The clear aperture of each lens may satisfy any of the following conditions.

[0442] Condition 1: CA_L1>CA_L2,CA_L3,CA_L4,CA_L5,CA_L6

[0443] Condition 2: CA_L1,CA_L5,CA_L6>CA_L2>CA_L3,CA_L4

[0444] Condition 3: CA_L1,CA_L2,CA_L4,CA_L5,CA_L6>CA_L3

[0445] Condition 4: CA_L1,CA_L2,CA_L5,CA_L6>CA_L4>CA_L3

[0446] Condition 5: CA_L1,CA_L6>CA_L5>CA_L2,CA_L3,CA_L4

[0447] Condition 6: CA_L1>CA_L6>CA_L2,CA_L3,CA_L4,CA_L5

[0448] In terms of refractive index, the refractive index of the first lens 201 is the largest among the lenses and can be greater than 1.8, for example, greater than 1.82. One or both of the third lens 203 and the sixth lens 206 can have the smallest refractive index among the lenses. For example, the refractive index of the fifth lens 205 can be the smallest among the lenses and can be less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index can be 0.2 or more. By providing a high-refractive-index lens made of glass closest to the object and setting the lens adjacent to the glass lens and the lens adjacent to the image sensor 600 to be low-refractive-index lenses made of plastic, the incidence efficiency can be improved, and the refractive power between the glass lens and the plastic lens can be adjusted to guide light to the image sensor 600.

[0449] The refractive index of each lens may satisfy any one of the following conditions.

[0450] Condition 1: n1>n2,n3,n4,n5,n6

[0451] Condition 2: n1, n3, n4, n6 > n2 > n5

[0452] Condition 3: n1, n4, n6 > n3 > n2, n5

[0453] Condition 4: n1>n4=n6>n2,n3,n5

[0454] Condition 5: n1, n2, n3, n4, n6 > n5

[0455] When comparing Abbe numbers, the fifth lens 205 has the largest Abbe number among the lenses and can be 50 or greater. The fourth lens 204 and the sixth lens 206 have the smallest Abbe numbers among the lenses and can be 20 or less. The difference between the maximum refractive index and the minimum Abbe number can be 30 or greater. By maximizing the Abbe number of the third lens 203, which is arranged at the center of the optical system 1100, and minimizing the Abbe number of the sixth lens 206, which has a low refractive index and is adjacent to the image sensor 600, the dispersion of light traveling between the glass lens and the plastic lens can be controlled, and the dispersion between the glass lens and the plastic lens can be increased to guide the light to the image sensor 600.

[0456] The Abbe number of each lens may satisfy any one of the following conditions.

[0457] Condition 1: v3, v6 > v1 > v2, v4, v5

[0458] Condition 2: v1, v3, v5 > v2 > v4, v6

[0459] Condition 3: v5 > v3 > v1, v2, v4, v6

[0460] Condition 4: v1, v2, v3, v5 > v4 = v6

[0461] Condition 5: v5 > v1, v2, v3, v4, v6

[0462] The focal lengths F1, F4, and F6 of the first lens 201, the fourth lens 204, and the sixth lens 206 may have a negative (-) sign. The first lens 201, the fourth lens 204, and the sixth lens 206 may have a negative (-) refractive power. The focal lengths F2, F3, and F5 of the second lens 202, the third lens 203, and the fifth lens 205 may have a positive (+) sign. The second lens 202, the third lens 203, and the fifth lens 205 may have a positive (+) refractive power. The second lens 202 and the third lens 203 with positive (+) refractive power may be placed on the sensor side of the first lens 201 with negative (-) refractive power. In this way, light incident from the object side can be moved away from the optical axis direction and then refocused on the optical axis direction, thereby forming a stable optical path.

[0463] In addition, the fifth lens 205 and the sixth lens 206 , which are adjacently arranged lenses, may satisfy the following conditions.

[0464] Condition 1: The refractive index of the lens with positive refractive power < the refractive index of the lens with negative refractive power

[0465] Condition 2: Dispersion value of lens with positive refractive power > dispersion value of lens with negative refractive power

[0466] Here, in the plastic lens, the fifth lens 205 has positive refractive power, and the sixth lens 206 has negative refractive power. Therefore, according to conditions 1 and 2, the refractive index of the fifth lens 205 is smaller than that of the sixth lens 206, and the dispersion value of the fifth lens 205 is larger than that of the sixth lens 206. Chromatic aberrations occurring in the plastic lens can be corrected by the plastic lens. In addition, the fifth lens 205 and the sixth lens 206, which are plastic lenses arranged in series, can compensate for chromatic aberrations occurring in the plastic lens by satisfying a refractive index difference of 0.1 or greater and 0.15 or less, and an Abbe number difference of 20 or greater and 50 or less.

[0467] Optical systems generate chromatic aberration and correct it using a cemented lens or two lenses arranged in series. As the temperature changes from low to high, the lenses repeatedly contract and expand. Because the lens properties of lenses made of the same material change by the same amount in response to temperature changes, correcting chromatic aberration between lenses made of the same material is effective even under temperature fluctuations. Therefore, in the second embodiment of the present disclosure, the fifth lens 205 and the sixth lens 206 can be used to correct chromatic aberration that occurs in plastic lenses.

[0468] When comparing focal lengths in absolute values, the focal length of the sixth lens 206 is the largest among the lenses and may be 10 or more and 20 or less. The focal length of the fourth lens 204 is the smallest among the lenses, and the absolute value of the focal length of the fifth lens 205 may be 3 or more and 5 or less.

[0469] The absolute value of the focal length of each lens may satisfy any one of the following conditions.

[0470] Condition 1: |f2|,|f3|,|f5|,|f6|>|f1|>|f4|

[0471] Condition 2: |f6|>|f2|>|f1|,|f3|,|f4|,|f5|

[0472] Condition 3: |f2|,|f6|>|f3|>|f1|,|f4|,|f5|

[0473] Condition 4: |f1|,|f2|,|f3|,|f5|,|f6|>|f4|

[0474] Condition 5: |f1|,|f4|>|f5|>|f2|,|f3|,|f6|

[0475] Condition 6: |f6|>|f1|,|f2|,|f3|,|f4|,|f5|

[0476] The thickness (T1) of the first lens 201 can be such that the difference between the maximum thickness and the minimum thickness is 1.5 times or greater, for example, within a range of 1.5 times to 1.8 times, and the center thickness CT1 can be the smallest and the edge thickness ET1 can be the largest. The thickness T2 of the second lens 202 can be such that the maximum thickness is 1 to 1.2 times the minimum thickness. The second lens 202 can have a maximum center thickness CT2 and a minimum edge thickness ET2. The thickness T3 of the third lens 203 can be greatest at the center and smallest at the edge, with the maximum thickness ranging from 1.2 to 1.5 times the minimum thickness. The thickness T4 of the fourth lens 204 can be smallest at the center and largest at the edge, with the maximum thickness ranging from 1.5 to 2 times the minimum thickness. The thickness T5 of the fifth lens 205 can be greatest at the center and smallest at the edge, with the maximum thickness ranging from 2.5 to 3 times the minimum thickness. The thickness T6 of the sixth lens 206 may be minimum at the center and maximum at the edge, and the maximum thickness is within a range of 1 to 1.5 times the minimum thickness.

[0477] The thickness of each lens may satisfy any one of the following conditions.

[0478] Condition 1: 0.1 <CT1 / ET1<1,1.5<ET1 / CT1<2

[0479] Condition 2: 1 <CT2 / ET2<1.3,0.8<ET2 / CT2<1

[0480] Condition 3: 1 <CT3 / ET3<1.5,0.5<ET3 / CT3<1

[0481] Condition 4: 0.1 <CT4 / ET4<1,1.5<ET4 / CT4<2

[0482] Condition 5: 2.5 <CT5 / ET5<3,0.1<ET5 / CT5<0.5

[0483] Condition 6: 0.5 <CT6 / ET6<1,1.1<ET6 / CT6<1.5

[0484] Condition 7: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0485] Among the distances G1 to G6 between the lenses, the first distance G1 between the first lens 201 and the second lens 202 may have a maximum value at the center and a minimum value at the edge. The second distance G2 between the second lens 202 and the third lens 203 may have a maximum value at the edge and a minimum value at the center. The third distance G3 between the third lens 203 and the fourth lens 204 may have a maximum value at the edge and a minimum value at the center. The fourth distance G4 between the fourth lens 204 and the fifth lens 205 may have a maximum value at the center and a minimum value at the edge. The fifth distance G5 between the fifth lens 205 and the sixth lens 206 may have a maximum value at the center and a minimum value at the edge.

[0486] Figure 18 、 Figure 20 as well as Figure 22 It shows Figure 14 The graph is a graph of diffraction MTF (Modulation Transfer Function) at room temperature, low temperature and high temperature in the optical system of FIG. , and is a graph showing the brightness ratio (modulation) according to the spatial frequency. Figure 18 、 Figure 20 as well as Figure 22 As shown, in the second embodiment of the present disclosure, the deviation of the MTF at a low temperature or a high temperature based on room temperature may be less than 10%, that is, 7% or less.

[0487] Figure 19 、 Figure 21 and Figure 23 It shows Figure 14 The aberration characteristics of the optical system at room temperature, low temperature and high temperature are shown in the graph. Figure 19 、 Figure 21 and Figure 23 In the aberration curve diagram, longitudinal spherical aberration, astigmatism field curve and distortion are measured. Figure 19 、 Figure 21 and Figure 23 In FIG, the X-axis may represent the focal length (mm) and the degree of distortion (%), and the Y-axis may represent the height of the image. In addition, the graph for spherical aberration is a graph for light in wavelength bands of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for astigmatism field curve and distortion is a graph for light in a wavelength band of about 546 nm. Figure 19 、 Figure 21 and Figure 23, it can be explained that the closer each curve at room temperature, low temperature, and high temperature is to the Y-axis, the better the aberration correction function is, and it can be seen that the optical system 1100 according to the second embodiment has measurement values ​​close to the Y-axis in almost all areas. In other words, the optical system 1100 according to the second embodiment has improved resolution and can have good optical performance not only at the center of the field of view (FOV) but also at the periphery. Here, the low temperature is -20 degrees or lower, for example, in the range of -20 degrees to -40 degrees, the room temperature is in the range of 22 degrees ± 5 degrees or in the range of 18 degrees to 27 degrees, and the high temperature can be 85 degrees or higher, for example, in the range of 85 degrees to 205 degrees. Therefore, it can be seen that at Figure 19 、 Figure 21 and Figure 23 The brightness ratio (modulation) from low temperature to high temperature decreases by less than 10%, for example, 5% or less, or hardly changes.

[0488] The optical system of the second embodiment disclosed above can effectively control aberration characteristics such as chromatic aberration and distortion, and can have good optical performance not only at the center of the field of view (FOV) but also at the periphery.

[0489] An optical system according to a third embodiment of the present disclosure will be described.

[0490] Figure 26 is a cross-sectional side view of an optical system and an image pickup device module having the optical system according to a third embodiment, Figure 27 It shows Figure 26 Table of aspheric coefficients of lenses in optical systems, Figure 28 It shows Figure 26 A table showing the thickness of each lens in an optical system and the distance between adjacent lenses. Figure 29 It shows Figure 26 Table of sag values ​​of the lens surfaces of the first lens to the sixth lens in the optical system, Figure 30 Is to show about Figure 26 The graph of the diffraction MTF (Modulation Transfer Function) data of the optical system at low temperature is shown in FIG. Figure 31 Is to show about Figure 26 A graph showing the aberration characteristics of an optical system at low temperatures. Figure 32 Is to show about Figure 26 A graph of the diffraction MTF data of an optical system at room temperature, Figure 33 Is to show about Figure 26 A graph showing the aberration characteristics of an optical system at room temperature. Figure 34 Is to show about Figure 26 The graph of the diffraction MTF data of the optical system at high temperature is shown in Figure 2. Figure 35Is to show about Figure 26 A graph showing the aberration characteristics of an optical system at high temperatures. Figure 36 Is to show about Figure 26 A graph showing the diffraction MTF data of the optical system at RGB wavelengths, and Figure 37 Is to show about Figure 26 A graph showing the diffraction MTF data of an optical system at IR wavelengths.

[0491] Reference Figure 26 The optical system 1200 includes a lens portion, and the lens portion may include first to sixth lenses 301 to 306. The first to sixth lenses 301 to 306 may be sequentially arranged along the optical axis OA of the optical system 1200. Light corresponding to information about an object may pass through the first to sixth lenses 301 to 306 and the optical filter 500 and be incident on the image sensor 600.

[0492] The first lens 301 may be positioned closest to the object side. The first lens 301 may be positioned farthest from the sensor side. The first lens 301 may have a negative (-) refractive power on the optical axis OA. The first lens 301 may be made of a plastic material or a glass material, and may be, for example, a glass material. The first lens 301 made of a glass material can reduce changes in the center position and curvature radius due to temperature changes in the surrounding environment, and can protect the incident side of the optical system 1200.

[0493] Based on the optical axis, the first surface S1 on the object side of the first lens 301 may be convex, and the second surface S2 on the sensor side may be concave. The first lens 301 may have a meniscus shape that is convex toward the object side. The first lens 301 may be made of glass and may have a spherical surface.

[0494] Due to the refractive properties of the first lens 301, the second lens 302 may be further spaced apart from the first lens 301. In other words, the central gap between the first lens 301 and the second lens 302 may be the largest within the lens portion.

[0495] The second lens 302 may be positioned second from the object side. The second lens 302 may be positioned fifth from the sensor side. The second lens 302 may be positioned between the first lens 301 and the third lens 303. The second lens 302 may have positive refractive power along the optical axis OA. The second lens 302 may be made of plastic or glass. For example, the second lens 302 may be made of plastic.

[0496] The third surface S3 on the object side of the second lens 302 may be concave relative to the optical axis OA, and the fourth surface S4 on the sensor side may be convex. The second lens 302 may have a meniscus shape, in which the sensor side is convex. The second lens 302 may be made of a plastic material and may be aspherical. At least one or both of the third surface S3 and the fourth surface S4 may be aspherical. The aspheric coefficients of the third surface S3 and the fourth surface S4 may be set to Figure 27 At least one or both of the third surface S3 and the fourth surface S4 may be configured to have no critical point from the optical axis OA to the end of the effective area.

[0497] An aperture stop can be arranged around the sensor-side fourth surface S4 of the second lens 302. An aperture stop can be arranged around the object-side fifth surface S5 of the third lens 303. This aperture can reduce the TTL within the field of view and enable miniaturization of the optical system. This can prevent a decrease in the weight yield of the optical system and improve production efficiency. Furthermore, the TTL within the horizontal field of view FOV_H of 130 to 160 degrees can be reduced, further miniaturizing the optical system.

[0498] The third lens 303 may be positioned third from the object side. The third lens 303 may be positioned fourth from the sensor side. The third lens 303 may be positioned between the second lens 302 and the fourth lens 304. The third lens 303 may have positive (+) refractive power along the optical axis OA. The third lens 303 may be made of plastic or glass. For example, the third lens 303 may be made of glass.

[0499] The fifth surface S5 on the object side of the third lens 303, based on the optical axis, may be convex, and the sixth surface S6 on the sensor side may be convex. The third lens 303 may have a shape with both sides convex. The third lens 303 may be made of glass and may be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 may be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 may be arranged so that there is no critical point from the optical axis OA to the end of the active area.

[0500] The fourth lens 304 may be positioned fourth from the object side. The fourth lens 304 may be positioned third from the sensor side. The fourth lens 304 may be positioned between the third lens 303 and the fifth lens 305. The fourth lens 304 may have positive (+) or negative (-) refractive power along the optical axis OA. The fourth lens 304 may have negative (-) refractive power. The fourth lens 304 may be made of plastic or glass. For example, the fourth lens 304 may be made of plastic.

[0501] The seventh surface S7 on the object side of the fourth lens 304 based on the optical axis may be convex, and the eighth surface S8 on the sensor side may be concave. The fourth lens 304 may have a meniscus shape in which the object side is convex. The fourth lens 304 may be made of a plastic material and may be aspherical. At least one or both of the seventh surface S7 and the eighth surface S8 may be aspherical. The aspherical coefficients of the seventh surface S7 and the eighth surface S8 may be set to Figure 27 At least one or both of the seventh surface S7 and the eighth surface S8 may be configured to have no critical point from the optical axis OA to the end of the effective area.

[0502] The fifth lens 305 may be positioned fifth from the object side. The fifth lens 305 may be positioned second from the sensor side. The fifth lens 305 may be positioned between the fourth lens 304 and the sixth lens 306. The fifth lens 305 may have positive (+) or negative (-) refractive power along the optical axis OA. The fifth lens 305 may have positive (+) refractive power. The fifth lens 305 may be made of plastic or glass. For example, the fifth lens 305 may be made of plastic.

[0503] The ninth surface S9 on the object side of the fifth lens 305 may be convex relative to the optical axis OA, and the tenth surface S10 on the sensor side of the fifth lens 305 may be convex. The fifth lens 305 may have a convex shape on both sides. The fifth lens 305 may be made of a plastic material and may be aspherical. At least one or both of the ninth surface S9 and the tenth surface S10 may be aspherical. The aspherical coefficients of the ninth surface S9 and the tenth surface S10 may be set to Figure 27 At least one or both of the ninth surface S9 and the tenth surface S10 may be provided to have no critical point from the optical axis OA to the end of the effective area.

[0504] The sixth lens 306 may be positioned furthest from the object side. The sixth lens 306 may be positioned closest to the image sensor 600. The sixth lens 306 may have positive (+) or negative (-) refractive power along the optical axis OA. The sixth lens 306 may have positive (+) refractive power. The sixth lens 306 may be made of plastic or glass. For example, the sixth lens 306 may be made of plastic.

[0505] Based on the optical axis OA, the eleventh surface S11 of the sixth lens 306 on the object side may be concave, and the twelfth surface S12 on the sensor side may be convex. The sixth lens 306 may have a meniscus shape with a convex sensor side. At least one or both of the eleventh surface S11 and the twelfth surface S12 may be aspherical. The aspheric coefficients of the eleventh surface S11 and the twelfth surface S12 may be set to Figure 27 At least one or both of the eleventh surface S11 and the twelfth surface S12 may be provided to have no critical point from the optical axis OA to the end of the effective area.

[0506] The sixth lens 306 can be a plastic lens closest to the image sensor 600. In addition, by arranging two or more plastic lenses adjacent to the image sensor 600, aberrations such as spherical aberration and chromatic aberration can be improved by having a lens surface with an aspherical surface, and the influence on resolution can be controlled. In addition, by arranging the plastic lens as a lens adjacent to the image sensor 600, the plastic lens can be insensitive to assembly tolerances compared to a glass lens. In other words, being insensitive to assembly tolerances means that even if the assembly is slightly different from the design during assembly, the optical performance may not be significantly affected. In addition, by setting the two lenses 305 and 306 adjacent to the image sensor 600 to plastic material, the optical performance can be improved by having a lens surface with an aspherical surface, and for example, aberration characteristics can be improved and resolution degradation can be prevented.

[0507] [Table 18]

[0508] lens surface radius thickness nd vd Semi-aperture focal length 1 S1 11.367 0.700 1.6200 60.3 3.997 -3.6129 S2 1.834 2.064 1.818 2 S3 -7.062 2.491 1.6400 23.5 1.800 8.1590 S4 -3.436 0.050 1.364 aperture infinity 0.446 1.180 3 S5 6.964 1.268 1.6200 60.3 1.200 3.9215 S6 -3.503 0.169 1.300 4 S7 33.745 0.600 1.6800 18.1 1.376 -3.9621 S8 2.510 0.417 1.555 5 S9 4.736 1.548 1.5350 55.8 1.906 5.0008 S10 -5.508 0.555 2.118 6 S11 -4.404 0.600 1.6800 18.1 2.212 185.3455 S12 -4.494 0.117 2.452 filter infinity 0.300 2.634 infinity 0.600 2.673 Cover infinity 1.573 2.796 image infinity 0.000 3.126

[0509] Table 18 shows the surface number (Surface), curvature radius (Radius), center thickness of each lens or distance between lens surfaces (Thickness), refractive index (Index, nd), Abbe number (Abbe, vd), effective radius (Semi Aperture), and focal length (Fcoal length) of the lenses according to the third embodiment of the present disclosure. The units of the curvature radius and thickness or distance may be mm.

[0510] [Table 19]

[0511] item value item value F 2.3725 F-number 2.2500 ET1 1.5603 FOV_H 152.0000 ET2 2.5017 EPD 1.0546 ET3 0.9143 BFL 2.5905 ET4 1.0355 TD 10.9092 ET5 0.6665 IhD 7.28 ET6 0.5448 SD 5.1581 ΣIndex 9.7750 TTL 13.4993 ΣAbbe 236.1100 GLca_Aver 4.157619 ΣCT 7.2078 PLca_Aver 3.6955537 ΣCG 3.7014 CT_max 2.4910 CA_max 5.815 CT_min 0.600 CA_min 2.500 CT_Aver 1.3013 CA_Aver 3.850 RGB_BFL 2.591 IR_BFL 2.598(+0.007)

[0512] Table 19 shows the terms of the above mathematical expression in the optical system 1200 of the present embodiment, including TTL (total track length) (mm), BFL (back focal length), effective focal length F (mm), ImgH (mm), clear aperture CA (mm), thickness (mm), TTL (mm), TD (mm), and the above terms are the optical axis distance from the first surface S1 to the twelfth surface S12 of the optical system 1200, the sum of the refractive index, the sum of the Abbe number, the sum of the thickness (mm), the sum of the distances between adjacent lenses, the clear aperture characteristics, the sum of the refractive indices of the glass lenses, the sum of the refractive indices of the plastic materials, the field of view (FOV_H) (degrees), the edge thickness ET, the F number, etc.

[0513] When the wavelength of light incident on the optical system 1200 changes, focus shift occurs. This phenomenon can be addressed by minimizing focus shift for the long-wavelength IR and visible RGB regions through optical design correction. Without design correction for RGB and IR wavelengths, focus shift of approximately 30 μm or greater may occur, potentially failing to maintain optical performance.

[0514] Referring to Table 19, the BFL at the RGB wavelength incident on the optical system 1200 according to the third embodiment is 1.2416um, and the BFL at the IR wavelength is 1.2510(+0.009)um, and the difference between the BFL at the RGB wavelength and the BFL at the IR wavelength is 0.0094um, thereby minimizing the focus shift phenomenon.

[0515] Currently, the application of vehicle surveillance lenses is increasing, and the use of visible light (RGB) and infrared (IR) is emerging as key performance features. During the day, visible light can be used to distinguish colors, while at night, infrared can be used to obtain color images and videos that are as good as those during daytime. Therefore, vehicle surveillance lenses must be able to operate stably and achieve high image quality during both daytime and nighttime driving. Optical lenses can be well matched with the visible light (RGB) and infrared (IR) chips installed in the vehicle, and can achieve visible light and infrared confocal focus for dual-use effects during both daytime and nighttime.

[0516] The center thicknesses of the first to sixth lenses 301 to 306 are denoted by CT1 to CT6, the edge thicknesses at the ends of the effective regions of each lens are denoted by ET1 to ET6, the center gaps between two adjacent lenses are denoted by CG1 to CG5, and the edge distances between the edges of each lens are denoted by EG1 to EG5. The back focal length (BFL) is the optical axis distance from the image sensor 600 to the center of the last lens. The TTL is the optical axis distance from the center of the first surface S1 of the first lens 301 to the top surface of the image sensor 600.

[0517] like Figure 27 As shown, in the lenses of the lens portion of the third embodiment, the lens surfaces of the second lens 302, the fourth lens 304, the fifth lens 305, and the sixth lens 306 may include aspheric surfaces having a 30th-order aspheric coefficient. For example, the second lens 302, the fourth lens 304, the fifth lens 305, and the sixth lens 306 may include lens surfaces having a 30th-order aspheric coefficient. As described above, since an aspheric surface having a 30th-order aspheric coefficient (non-zero value) can significantly change the aspheric shape of the periphery, it can effectively correct the optical performance of the periphery of the field of view (FOV).

[0518] The thicknesses T1 to T6 of the first to sixth lenses 301 to 306 and the distances G1 to G5 between two adjacent lenses may be set. Figure 15 As shown, the thickness T1 to T6 of each lens in the Y-axis direction can be expressed as a distance of 0.1 mm or 0.2 mm or more, and the distance G1 to G5 between each lens can be expressed as a distance of 0.1 mm or 0.2 mm or more.

[0519] When comparing the absolute values ​​of the curvature radii of each lens, the curvature radius of the seventh surface S7 of the fourth lens 304 on the optical axis OA may be the largest among the lenses, and the curvature radius of the second surface S2 of the first lens 301 may be the smallest among the lenses. The difference between the maximum curvature radius and the minimum curvature radius may be 25 times or more, for example, 26 times to 30 times.

[0520] Since the clear aperture of the plastic lens is smaller than that of the glass lens, the lens arranged on the object side of the plastic lens can have a strong refractive power to refract light into the plastic lens. In addition, the curvature radius of the lens surface can be smaller to enhance the refractive power.

[0521] The absolute value of the radius of curvature of the first surface S1 of the first lens 301 may be greater than the absolute value of the radius of curvature of the second surface S2. The absolute value of the radius of curvature of the third surface S3 of the second lens 302 may be greater than the absolute value of the radius of curvature of the fourth surface S4. The absolute value of the radius of curvature of the fifth surface S5 of the third lens 303 may be greater than the absolute value of the radius of curvature of the sixth surface S6. The absolute value of the radius of curvature of the seventh surface S7 of the fourth lens 304 may be greater than the absolute value of the radius of curvature of the eighth surface S8. The absolute value of the radius of curvature of the ninth surface S9 of the fifth lens 305 may be smaller than the absolute value of the radius of curvature of the tenth surface S10. The absolute value of the radius of curvature of the eleventh surface S11 of the sixth lens 306 may be smaller than the absolute value of the radius of curvature of the twelfth surface S12.

[0522] The ratio of the curvature radius of each lens may satisfy the following conditions.

[0523] Condition 1: 6 < |L1R1 / L1R2| < 6.5

[0524] Condition 2: 2<|L2R1 / L2R2|<3

[0525] Condition 3: 1.5 < |L3R1 / L3R2| < 2.5

[0526] Condition 4: 10 < |L4R1 / L4R2| < 15

[0527] Condition 5: 0.1 < |L5R1 / L5R2| < 1

[0528] Condition 6: 0.1 < |L6R1 / L6R2| < 1

[0529] When describing the center thickness CT of the lens based on the optical axis, the center thickness CT2 of the second lens 302 is the largest among the lenses, and the center thickness CT4 of the fourth lens 304 and the center thickness CT6 of the sixth lens 306 are the smallest among the lenses. The difference between the maximum center thickness and the minimum center thickness of the lens may be within a range of 2 mm or more and 2.5 mm or less.

[0530] The center thickness of each lens may satisfy any one of the following conditions.

[0531] Condition 1: CT2, CT3, CT5 > CT1 > CT4, CT6

[0532] Condition 2: CT2>CT1,CT3,CT4,CT5,CT6

[0533] Condition 3: CT2, CT5 > CT3 > CT1, CT4, CT6

[0534] Condition 4: CT1, CT2, CT3, CT5 > CT4 = CT6

[0535] Condition 5: CT2>CT5>CT1,CT3,CT4,CT6

[0536] If the center gaps CG between the lenses are described, the center gap CG1 between the first lens 301 and the second lens 302 may be the largest, and the center gap CG3 between the third lens 303 and the fourth lens 304 may be the smallest. The difference between the maximum center gap and the minimum center gap in the lens distance may be 1 mm or more, for example, in the range of 1.5 mm to 2 mm.

[0537] The center gap between each lens can satisfy the following conditions.

[0538] Condition 1: CG1>CG2,CG3,CG4,CG5

[0539] Condition 2: CG1, CG5 > CG2 > CG3, CG4

[0540] Condition 3: CG1, CG2, CG4, CG5 > CG3

[0541] Condition 4: CG1, CG2, CG5 > CG4 > CG3

[0542] Condition 5: CG1>CG5>CG2,CG3,CG4

[0543] In terms of clear aperture, the lens with the largest clear aperture can be positioned between the first lens 301 closest to the subject and the sixth lens 306 closest to the image sensor 600. The lens with the largest clear aperture can be a glass lens. The lens with the largest clear aperture can be the first lens 301. Here, the clear aperture is the average of the clear apertures on the subject side and the sensor side of each lens. The lens surface with the largest clear aperture can be the first surface S1 of the first lens 301.

[0544] The lens with the smallest clear aperture may be a lens disposed between the aperture stop and the image sensor 600. The lens with the smallest clear aperture may be the third lens 303. The lens surface with the smallest clear aperture may be the fifth surface S5 of the third lens 303. The clear aperture of a lens made of plastic may be smaller than the clear aperture of a lens made of glass. The plastic lens may be placed adjacent to the image sensor.

[0545] The clear aperture of each lens may satisfy any of the following conditions.

[0546] Condition 1: CA_L1>CA_L2,CA_L3,CA_L4,CA_L5,CA_L6

[0547] Condition 2: CA_L1,CA_L5,CA_L6>CA_L2>CA_L3,CA_L4

[0548] Condition 3: CA_L1,CA_L2,CA_L4,CA_L5,CA_L6>CA_L3

[0549] Condition 4: CA_L1,CA_L2,CA_L5,CA_L6>CA_L4>CA_L3

[0550] Condition 5: CA_L1,CA_L6>CA_L5>CA_L2,CA_L3,CA_L4

[0551] Condition 6: CA_L1>CA_L6>CA_L2,CA_L3,CA_L4,CA_L5

[0552] In terms of refractive index, the fourth lens 304 and the sixth lens 306 have the largest refractive index among the lenses and may be greater than 1.65, for example, greater than 1.67. The fifth lens 305 may have the smallest refractive index among the lenses. For example, the refractive index of the fifth lens 305 may be the smallest among the lenses and may be less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index may be 0.2 or more. By providing a high-refractive-index lens made of glass closest to the object and configuring the lens adjacent to the glass lens and the lens adjacent to the image sensor 600 as low-refractive-index lenses made of plastic, the incidence efficiency can be improved, and the refractive power between the glass lens and the plastic lens can be adjusted to guide light to the image sensor 600.

[0553] The refractive index of each lens may satisfy any one of the following conditions.

[0554] Condition 1: n2, n4, n6 > n1 = n3 > n3, n5

[0555] Condition 2: n4, n6 > n2 > n1, n3, n5

[0556] Condition 3: n4 = n6 > n1, n2, n3, n5

[0557] Condition 4: n1, n2, n3, n4, n6 > n5

[0558] When comparing Abbe numbers, the first and third lenses 301 and 303 have the largest Abbe numbers among the lenses and can be 55 or greater. The fourth and sixth lenses 304 and 306 have the smallest Abbe numbers among the lenses and can be 20 or less. The difference between the maximum refractive index and the minimum Abbe number can be 30 or greater. By maximizing the Abbe number of the third lens 303, which is positioned at the center of the optical system 1200, and minimizing the Abbe number of the sixth lens 306, which has a low refractive index and is adjacent to the image sensor 600, the dispersion of light traveling between the glass lens and the plastic lens can be controlled, and the dispersion between the glass lens and the plastic lens can be increased to guide the light toward the image sensor 600.

[0559] The Abbe number of each lens may satisfy any of the following conditions.

[0560] Condition 1: v1 = v3 > v2, v4, v5, v6

[0561] Condition 2: v1, v3, v5 > v2 > v4, v6

[0562] Condition 3: v1, v2, v3, v5 > v4 = v6

[0563] Condition 4: v1, v3 > v5 > v2, v4, v6

[0564] The focal length F1 of the first lens 301 and the focal length F4 of the fourth lens 304 may have a negative (-) sign. The first lens 301 and the fourth lens 304 may have negative (-) refractive power. The focal length F2 of the second lens 302, the focal length F3 of the third lens 303, the focal length F5 of the fifth lens 305, and the focal length F6 of the sixth lens 306 may have a positive (+) sign. The second lens 302, the third lens 303, the fifth lens 305, and the sixth lens 306 may have positive (+) refractive power. The second lens 302 and the third lens 303 with positive (+) refractive power may be arranged on the sensor side of the first lens 301 with negative (-) refractive power. In this way, light incident from the object side can be moved away from the optical axis direction and then gathered again in the optical axis direction, thereby forming a stable optical path.

[0565] When comparing focal lengths in absolute values, the focal length of the sixth lens 306 is the largest among the lenses and may be 150 or more and 200 or less. The focal length of the first lens 301 is the smallest among the lenses, and the absolute value of the focal length of the first lens 301 may be 3 or more and 5 or less.

[0566] The absolute value of the focal length of each lens may satisfy any one of the following conditions.

[0567] Condition 1: |f2|,|f3|,|f4|,|f5|,|f6|>|f1|

[0568] Condition 2: |f6|>|f2|>|f1|,|f3|,|f4|,|f5|

[0569] Condition 3: |f2|,|f4|,|f5|,|f6|>|f3|>|f1|

[0570] Condition 4: |f2|,|f5|,|f6|>|f4|>|f1|,|f3|

[0571] Condition 5: |f2|,|f6|>|f5|>|f1|,|f3|,|f4|

[0572] Condition 6: |f6|>|f1|,|f2|,|f3|,|f4|,|f5|

[0573] The thickness T1 of the first lens 301 may be at least twice the difference between the maximum and minimum thicknesses, for example, within a range of 2 to 2.5 times. The thickness CT1 may be minimum at the center and the thickness ET1 may be maximum at the edge. The thickness T2 of the second lens 302 may be maximum within a range of 1 to 1.2 times the minimum thickness. The thickness CT2 of the second lens 302 may be minimum at the center and maximum at the edge. The thickness T3 of the third lens 303 may be maximum at the center and minimum at the edge, with the maximum thickness within a range of 1.2 to 1.5 times the minimum thickness. The thickness T4 of the fourth lens 304 may be minimum at the center and maximum at the edge, with the maximum thickness within a range of 1.5 to 2 times the minimum thickness. The thickness T5 of the fifth lens 305 may be maximum at the center and minimum at the edge, with the maximum thickness within a range of 2 to 2.5 times the minimum thickness. The thickness T6 of the sixth lens 306 may be minimum at the center and maximum at the edge, with the maximum thickness within a range of 1 to 1.5 times the minimum thickness.

[0574] The thickness of each lens may satisfy any one of the following conditions.

[0575] Condition 1: 0.1 <CT1 / ET1<0.5,2<ET1 / CT1<2.5

[0576] Condition 2: 0.5 <CT2 / ET2<1,1<ET2 / CT2<1.5

[0577] Condition 3: 1 <CT3 / ET3<1.5,0.5<ET3 / CT3<1

[0578] Condition 4: 0.1 <CT4 / ET4<1,1.5<ET4 / CT4<2

[0579] Condition 5: 2 <CT5 / ET5<2.5,0.1<ET5 / CT5<0.5

[0580] Condition 6: 1 <CT6 / ET6<1.5,0.5<ET6 / CT6<1

[0581] Condition 7: 0.5 < ΣCT / ΣET < 1, 1 < ΣET / ΣCT < 1.5

[0582] Among the distances G1 to G6 between the lenses, the first distance G1 between the first lens 301 and the second lens 302 may have a maximum value at the center and a minimum value at the edge. The second distance G2 between the second lens 302 and the third lens 303 may have a maximum value at the edge and a minimum value at the center. The third distance G3 between the third lens 303 and the fourth lens 304 may have a maximum value at the edge and a minimum value at the center. The fourth distance G4 between the fourth lens 304 and the fifth lens 305 may have a maximum value at the center and a minimum value at the edge. The fifth distance G5 between the fifth lens 305 and the sixth lens 306 may have a maximum value at the center and a minimum value at the edge.

[0583] Figure 30 、 Figure 32 and Figure 34 It shows Figure 26 The graph is a graph of diffraction MTF (Modulation Transfer Function) at room temperature, low temperature and high temperature in the optical system of FIG. , and is a graph showing the brightness ratio (modulation) according to the spatial frequency. Figure 30 、 Figure 32 and Figure 34 As shown, in the third embodiment of the present disclosure, the deviation of the MTF at a low temperature or a high temperature based on room temperature may be less than 10%, that is, 7% or less.

[0584] Figure 31 、 Figure 33 and Figure 35 It shows Figure 26 Graphs showing aberration characteristics of an optical system at room temperature, low temperature, and high temperature. Figure 31 、 Figure 33 and Figure 35 The aberration curve graph is a graph that measures longitudinal spherical aberration, astigmatism field curve and distortion. Figure 31 、 Figure 33 and Figure 35 In FIG, the X-axis may represent the focal length (mm) and the degree of distortion (%), and the Y-axis may represent the height of the image. In addition, the graph for spherical aberration is a graph for light having wavelength bands of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for astigmatism field curve and distortion is a graph for light having a wavelength band of about 546 nm. Figure 31 、 Figure 33 and Figure 35, it can be explained that the closer the corresponding curves at room temperature, low temperature, and high temperature are to the Y-axis, the better the aberration correction function. It can be seen that the optical system 1200 according to the third embodiment has measurement values ​​close to the Y-axis in almost all areas. In other words, the optical system 1200 according to the third embodiment has improved resolution and can have good optical performance not only in the center of the field of view (FOV) but also in the periphery. Here, the low temperature is -20 degrees or lower, for example, in the range of -20 degrees to -40 degrees, the room temperature is in the range of 22 degrees ± 5 degrees or in the range of 18 degrees to 27 degrees, and the high temperature can be 85 degrees or higher, for example, in the range of 85 degrees to 305 degrees. Therefore, it can be seen that at Figure 31 、 Figure 33 and Figure 35 The brightness ratio (modulation) from low temperature to high temperature decreases by less than 10%, for example, by 5% or less, or hardly changes.

[0585] The optical system of the third embodiment disclosed above can effectively control aberration characteristics such as chromatic aberration and distortion, and can have good optical performance not only at the center of the field of view (FOV_H) but also at the periphery.

[0586] An optical system according to a fourth embodiment of the present disclosure will be described.

[0587] Figure 38 is a cross-sectional side view of an optical system and an image pickup device module having the optical system according to a fourth embodiment, Figure 39 It shows Figure 38 Table of aspheric coefficients of lenses in optical systems, Figure 40 It shows Figure 38 A table showing the thickness of each lens of an optical system and the distance between adjacent lenses. Figure 41 It shows Figure 38 Table of sag values ​​of the lens surfaces of the first lens to the sixth lens in the optical system, Figure 42 Is to show about Figure 38 The graph of the diffraction MTF (Modulation Transfer Function) data of the optical system at low temperature is shown in FIG. Figure 43 Is to show about Figure 38 A graph showing the aberration characteristics of an optical system at low temperatures. Figure 44 Is to show about Figure 38 A graph of the diffraction MTF data of an optical system at room temperature, Figure 45 Is to show about Figure 38 A graph showing the aberration characteristics of an optical system at room temperature. Figure 46 Is to show about Figure 38 The graph of the diffraction MTF data of the optical system at high temperature is shown in Figure 2. Figure 47Is to show about Figure 38 A graph showing the aberration characteristics of an optical system at high temperatures. Figure 48 Is to show about Figure 38 A graph showing the diffraction MTF data of the optical system at RGB wavelengths, and Figure 49 Is to show about Figure 38 A graph showing the diffraction MTF data of an optical system at IR wavelengths.

[0588] Reference Figure 38 The optical system 1300 includes a lens portion, and the lens portion may include first to sixth lenses 401 to 406. The first to sixth lenses 401 to 406 may be sequentially arranged along the optical axis OA of the optical system 1300. Light corresponding to information about an object may pass through the first to sixth lenses 401 to 406 and the optical filter 500 and be incident on the image sensor 600.

[0589] The first lens 401 may be positioned closest to the object side. The first lens 401 may be positioned farthest from the sensor side. The first lens 401 may have a negative (-) refractive power on the optical axis OA. The first lens 401 may be made of a plastic material or a glass material, and may be, for example, a glass material. The first lens 401 made of a glass material can reduce changes in the center position and curvature radius due to temperature changes in the surrounding environment, and can protect the incident side of the optical system 1300.

[0590] Based on the optical axis, the first surface S1 on the object side of the first lens 401 may be convex, and the second surface S2 on the sensor side may be concave. The first lens 401 may have a meniscus shape that is convex toward the object side. The first lens 401 may be made of glass and may have a spherical surface.

[0591] Due to the refractive properties of the first lens 401, the second lens 402 can be further separated from the first lens 401. In other words, the center gap between the first lens 401 and the second lens 402 can be the largest within the lens portion.

[0592] The refractive index n1 of first lens 401 can satisfy the conditions n1>1.55 or n1>1.6. Since the refractive index n1 of first lens 401 is the highest among all lenses, the radius of curvature of first lens 401 and second lens 402 can be increased, which facilitates lens manufacturing. If the refractive index n1 of first lens 401 is less than this condition, the lens surfaces must be formed into sharp concave or convex shapes to increase the refractive power of first lens 401 and second lens 402. In this case, lens manufacturing becomes difficult, the lens defect rate increases, and this can lead to reduced production yields.

[0593] The second lens 402 may be positioned second from the object side. The second lens 402 may be positioned fifth from the sensor side. The second lens 402 may be positioned between the first lens 401 and the third lens 403. The second lens 402 may have positive (+) refractive power along the optical axis OA. The second lens 402 may be made of plastic or glass. For example, the second lens 402 may be made of plastic.

[0594] The third surface S3 on the object side of the second lens 402 may be concave relative to the optical axis OA, and the fourth surface S4 on the sensor side may be convex. The second lens 402 may have a meniscus shape, in which the sensor side is convex. The second lens 402 may be made of a plastic material and may be aspherical. At least one or both of the third surface S3 and the fourth surface S4 may be aspherical. The aspheric coefficients of the third surface S3 and the fourth surface S4 may be set to Figure 39 At least one or both of the third surface S3 and the fourth surface S4 may be configured to have no critical point from the optical axis OA to the end of the effective area.

[0595] An aperture stop can be arranged around the sensor-side fourth surface S4 of the second lens 402. An aperture stop can be arranged around the object-side fifth surface S5 of the third lens 403. This aperture can reduce the time-to-lose (TTL) within the field of view (FOV_H), enabling miniaturization of the optical system. This can prevent a decrease in the weight yield of the optical system and improve production efficiency. Furthermore, the optical system can be miniaturized by reducing the TTL within the horizontal field of view (FOV_H) of 130 to 160 degrees.

[0596] The third lens 403 may be positioned third from the object side. The third lens 403 may be positioned fourth from the sensor side. The third lens 403 may be positioned between the second lens 402 and the fourth lens 404. The third lens 403 may have positive (+) refractive power along the optical axis OA. The third lens 403 may be made of plastic or glass. For example, the third lens 403 may be made of glass.

[0597] The fifth surface S5 on the object side of the third lens 403 may be convex relative to the optical axis, and the sixth surface S6 on the sensor side may be convex. The third lens 403 may have a convex shape on both sides. The third lens 403 may be made of glass and may be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 may be spherical. At least one or both of the fifth surface S5 and the sixth surface S6 may be arranged so that there is no critical point from the optical axis OA to the end of the active area.

[0598] The fourth lens 404 may be positioned fourth from the object side. The fourth lens 404 may be positioned third from the sensor side. The fourth lens 404 may be positioned between the third lens 403 and the fifth lens 405. The fourth lens 404 may have positive (+) or negative (-) refractive power along the optical axis OA. The fourth lens 404 may have negative (-) refractive power. The fourth lens 404 may be made of plastic or glass. For example, the fourth lens 404 may be made of plastic.

[0599] Based on the optical axis, the seventh surface S7 on the object side of the fourth lens 404 may be convex, and the eighth surface S8 on the sensor side may be concave. The fourth lens 404 may have a meniscus shape in which the object side is convex. The fourth lens 404 may be made of a plastic material and may be aspherical. At least one or both of the seventh surface S7 and the eighth surface S8 may be aspherical. The aspherical coefficients of the seventh surface S7 and the eighth surface S8 may be set to Figure 39 At least one or both of the seventh surface S7 and the eighth surface S8 may be configured to have no critical point from the optical axis OA to the end of the effective area.

[0600] The fifth lens 405 may be positioned fifth from the object side. The fifth lens 405 may be positioned second from the sensor side. The fifth lens 405 may be positioned between the fourth lens 404 and the sixth lens 406. The fifth lens 405 may have positive (+) or negative (-) refractive power along the optical axis OA. The fifth lens 405 may have positive (+) refractive power. The fifth lens 405 may include a plastic material or a glass material. For example, the fifth lens 405 may be configured as a plastic material.

[0601] Based on the optical axis OA, the ninth surface S9 on the object side of the fifth lens 405 may be convex, and the tenth surface S10 on the sensor side may be convex. The fifth lens 405 may have a convex shape on both sides. The fifth lens 405 may be made of a plastic material and may be aspherical. At least one or both of the ninth surface S9 and the tenth surface S10 may be aspherical. The aspherical coefficients of the ninth surface S9 and the tenth surface S10 may be set to Figure 39 At least one or both of the ninth surface S9 and the tenth surface S10 may be provided to have no critical point from the optical axis OA to the end of the effective area.

[0602] The sixth lens 406 may be positioned furthest from the object side. The sixth lens 406 may be positioned closest to the image sensor 600. The sixth lens 406 may have positive (+) or negative (-) refractive power along the optical axis OA. The sixth lens 406 may have negative (-) refractive power. The sixth lens 406 may be made of plastic or glass. For example, the sixth lens 406 may be made of plastic.

[0603] Based on the optical axis OA, the eleventh surface S11 of the sixth lens 406 on the object side may be concave, and the twelfth surface S12 on the sensor side may be convex. The sixth lens 406 may have a meniscus shape with a convex sensor side. At least one or both of the eleventh surface S11 and the twelfth surface S12 may be aspherical. The aspheric coefficients of the eleventh surface S11 and the twelfth surface S12 may be set to Figure 39 At least one or both of the eleventh surface S11 and the twelfth surface S12 may be provided to have no critical point from the optical axis OA to the end of the effective area.

[0604] The sixth lens 406 can be a plastic lens closest to the image sensor 600. In addition, by arranging two or more plastic lenses adjacent to the image sensor 600, aberrations such as spherical aberration and chromatic aberration can be improved by having an aspherical lens surface, and the influence on resolution can be controlled. In addition, by arranging the plastic lens as a lens adjacent to the image sensor 600, the plastic lens can be insensitive to assembly tolerances compared to a glass lens. In other words, being insensitive to assembly tolerances means that even if the assembly is slightly different from the design during assembly, the optical performance may not be significantly affected. In addition, by setting the two lenses 405 and 406 adjacent to the image sensor 600 to plastic material, the optical performance can be improved by having an aspherical lens surface, and for example, aberration characteristics can be improved and resolution degradation can be prevented.

[0605] [Table 20]

[0606]

[0607] Table 20 shows the surface number (Surface), curvature radius (Radius), center thickness of each lens or distance between lens surfaces (Thickness), refractive index (Index, nd), Abbe number (Abbe, vd), effective radius (Semi Aperture), and focal length (Fcoal length) of the lenses according to the fourth embodiment of the present disclosure. The units of the curvature radius and thickness or distance may be mm.

[0608] [Table 21]

[0609] item value item value F 2.3345 F-number 2.23 ET1 1.5873 FOV_H 152.0 ET2 1.9753 EPD 1.0449 ET3 0.8944 BFL 2.2413 ET4 0.9953 TD 11.2593 ET5 0.6385 IhD 7.28 ET6 0.9478 SD 5.7336 ΣIndex 9.7040 TTL 13.5002 ΣAbbe 242.45 GLca_Aver 4.372 ΣCT 7.1445 PLca_Aver 3.751 ΣCG 4.1073 CT_max 2.0330 CA_max 6.242 CT_min 0.600 CA_min 2.504 CT_Aver 1.1908 CA_Aver 3.959 RGB_BFL 2.241 IR_BFL 2.249(+0.008)

[0610] Table 21 shows the terms of the above mathematical expression in the optical system 1300 of the fourth embodiment, including TTL (total track length) (mm), BFL (back focal length), effective focal length F (mm), ImgH (mm), clear aperture CA (mm), thickness (mm), TTL (mm), TD (mm), and the above terms are the optical axis distance from the first surface S1 to the twelfth surface S12 of the optical system 1300, the sum of the refractive index, the sum of the Abbe number, the sum of the thickness (mm), the sum of the distances between adjacent lenses, the clear aperture characteristics, the sum of the refractive indices of the glass lenses, the sum of the refractive indices of the plastic materials, the field of view (FOV_D) (degrees), the edge thickness ET, the F number, etc.

[0611] When the wavelength of light incident on the optical system 1300 changes, focus shift occurs. This phenomenon can be addressed by minimizing focus shift for the long-wavelength IR and visible RGB regions through optical design correction. Without design correction for RGB and IR wavelengths, focus shift of approximately 30 μm or greater may occur, potentially failing to maintain optical performance.

[0612] Referring to Table 21, the BFL at the RGB wavelength incident on the optical system 1300 according to the fourth embodiment is 2.241um, and the BFL at the IR wavelength is 2.249(+0.008)um, and the difference between the BFL at the RGB wavelength and the BFL at the IR wavelength is 0.008um, thereby minimizing the focus shift phenomenon.

[0613] Currently, the application of vehicle surveillance lenses is increasing, and the use of visible light (RGB) and infrared (IR) is emerging as key performance features. During the day, visible light can be used to distinguish colors, while at night, infrared can be used to obtain color images and videos that are as good as those during daytime. Therefore, vehicle surveillance lenses must be able to operate stably and achieve high image quality during both daytime and nighttime driving. Optical lenses can be well matched with the visible light (RGB) and infrared (IR) chips installed in the vehicle, and can achieve visible light and infrared confocal focus for dual-use effects during both daytime and nighttime.

[0614] The center thicknesses of the first to sixth lenses 401 to 406 are denoted by CT1 to CT6, the edge thicknesses at the ends of the effective regions of each lens are denoted by ET1 to ET6, the center gaps between two adjacent lenses are denoted by CG1 to CG5, and the edge distances between the edges of each lens are denoted by EG1 to EG5. The back focus (BFL) is the optical axis distance from the image sensor 600 to the center of the last lens. The TTL is the optical axis distance from the center of the first surface S1 of the first lens 401 to the top surface of the image sensor 600.

[0615] like Figure 39 As shown, in the lenses of the lens portion of the fourth embodiment, the lens surfaces of the second lens 402, the fourth lens 404, the fifth lens 405, and the sixth lens 406 may include aspheric surfaces having a 30th-order aspheric coefficient. For example, the second lens 402, the fourth lens 404, the fifth lens 405, and the sixth lens 406 may include lens surfaces having a 30th-order aspheric coefficient. As described above, since an aspheric surface having a 30th-order aspheric coefficient (non-zero value) can significantly change the aspheric shape of the periphery, it can effectively correct the optical performance of the periphery of the field of view (FOV).

[0616] The thicknesses T1 to T6 of the first to sixth lenses 401 to 406 and the distances G1 to G5 between two adjacent lenses may be set. Figure 40 As shown, the thickness T1 to T6 of each lens in the Y-axis direction can be expressed as a distance of 0.1 mm or 0.2 mm or more, and the distance G1 to G5 between each lens can be expressed as a distance of 0.1 mm or 0.2 mm or more.

[0617] When comparing the absolute values ​​of the curvature radii of each lens, the curvature radius of the seventh surface S7 of the fourth lens 404 on the optical axis OA may be the largest among the lenses, and the curvature radius of the eleventh surface S11 of the sixth lens 406 may be the smallest among the lenses. The difference between the maximum curvature radius and the minimum curvature radius may be 5 times or more, for example, 5.5 times to 6 times.

[0618] Since the clear aperture of the plastic lens is smaller than that of the glass lens, the lens arranged on the object side of the plastic lens can have a strong refractive power, thereby refracting light into the plastic lens. In addition, the curvature radius of the lens surface can be smaller to enhance the refractive power.

[0619] The absolute value of the radius of curvature of the first surface S1 of the first lens 401 may be greater than the absolute value of the radius of curvature of the second surface S2. The absolute value of the radius of curvature of the third surface S3 of the second lens 402 may be greater than the absolute value of the radius of curvature of the fourth surface S4. The absolute value of the radius of curvature of the fifth surface S5 of the third lens 403 may be greater than the absolute value of the radius of curvature of the sixth surface S6. The absolute value of the radius of curvature of the seventh surface S7 of the fourth lens 404 may be greater than the absolute value of the radius of curvature of the eighth surface S8. The absolute value of the radius of curvature of the ninth surface S9 of the fifth lens 405 may be greater than the absolute value of the radius of curvature of the tenth surface S10. The absolute value of the radius of curvature of the eleventh surface S11 of the sixth lens 406 may be smaller than the absolute value of the radius of curvature of the twelfth surface S12.

[0620] The ratio of the curvature radius of each lens may satisfy the following conditions.

[0621] Condition 1: 6 < |L1R1 / L1R2| < 6.5

[0622] Condition 2: 1.8 < |L2R1 / L2R2| < 2.2

[0623] Condition 3: 1.8 < |L3R1 / L3R2| < 2.2

[0624] Condition 4: 10 < |L4R1 / L4R2| < 15

[0625] Condition 5: 0.1 < |L5R1 / L5R2| < 1

[0626] Condition 6: 0.8 <L6R1 / L6R2<1.2

[0627] When describing the center thickness CT of the lens based on the optical axis, the center thickness CT2 of the second lens 402 is the largest among the lenses, and the center thicknesses CT4 of the fourth lens 404 and the sixth lens 406 are the smallest among the lenses. The difference between the maximum center thickness and the minimum center thickness of the lens may be within a range of 2 mm or more and 2.5 mm or less.

[0628] The center thickness of each lens may satisfy any one of the following conditions.

[0629] Condition 1: CT2, CT3, CT5 > CT1 > CT4, CT6

[0630] Condition 2: CT2>CT1,CT3,CT4,CT5,CT6

[0631] Condition 3: CT2, CT5 > CT3 > CT1, CT4, CT6

[0632] Condition 4: CT1, CT2, CT3, CT5 > CT4 = CT6

[0633] Condition 5: CT2>CT5>CT1,CT3,CT4,CT6

[0634] If the center gaps CG between the lenses are described, the center gap CG1 between the first lens 401 and the second lens 402 may be the largest, and the center gap CG3 between the third lens 403 and the fourth lens 404 may be the smallest. The difference between the maximum center gap and the minimum center gap in the lens distance may be 1 mm or more, for example, in the range of 1.5 mm to 2 mm.

[0635] The center gap between each lens can satisfy the following conditions.

[0636] Condition 1: CG1>CG2,CG3,CG4,CG5

[0637] Condition 2: CG1, CG5 > CG2 > CG3, CG4

[0638] Condition 3: CG1, CG2, CG4, CG5 > CG3

[0639] Condition 4: CG1, CG2, CG5 > CG4 > CG3

[0640] Condition 5: CG1>CG5>CG2,CG3,CG4

[0641] Regarding the clear aperture, the lens with the largest clear aperture can be positioned between the first lens 401 closest to the subject and the sixth lens 406 closest to the image sensor 600. The lens with the largest clear aperture can be a glass lens. The lens with the largest clear aperture can be the first lens 401. Here, the clear aperture is the average of the clear apertures on the subject side and the sensor side of each lens. The lens surface with the largest clear aperture can be the first surface S1 of the first lens 401.

[0642] The lens with the smallest clear aperture may be a lens disposed between the aperture stop and the image sensor 600. The lens with the smallest clear aperture may be the third lens 403. The lens surface with the smallest clear aperture may be the fifth surface S5 of the third lens 403. The clear aperture of a lens made of plastic may be smaller than the clear aperture of a lens made of glass. The lens made of plastic may be disposed adjacent to the image sensor.

[0643] The clear aperture of each lens may satisfy any of the following conditions.

[0644] Condition 1: CA_L1>CA_L2,CA_L3,CA_L4,CA_L5,CA_L6

[0645] Condition 2: CA_L1,CA_L5,CA_L6>CA_L2>CA_L3,CA_L4

[0646] Condition 3: CA_L1,CA_L2,CA_L4,CA_L5,CA_L6>CA_L3

[0647] Condition 4: CA_L1,CA_L2,CA_L5,CA_L6>CA_L4>CA_L3

[0648] Condition 5: CA_L1,CA_L6>CA_L5>CA_L2,CA_L3,CA_L4

[0649] Condition 6: CA_L1>CA_L6>CA_L2,CA_L3,CA_L4,CA_L5

[0650] In terms of refractive index, the sixth lens 406 has the largest refractive index among the lenses and may be greater than 1.6, for example, greater than 1.65. The fifth lens 405 may have the smallest refractive index among the lenses. The refractive index of the fifth lens 405 may be less than 1.6, for example, less than 1.55. The difference between the maximum refractive index and the minimum refractive index may be 0.2 or more. By providing a high-refractive-index lens made of glass closest to the object and configuring the lens adjacent to the glass lens and the lens adjacent to the image sensor 600 as low-refractive-index lenses made of plastic, the incidence efficiency can be improved, and the refractive power between the glass lens and the plastic lens can be adjusted to guide light to the image sensor 600.

[0651] The refractive index of each lens may satisfy any one of the following conditions.

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

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

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

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

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

[0657] When comparing Abbe numbers, the third lens 403 has the largest Abbe number among the lenses and can be 50 or greater. The sixth lens 406 has the smallest Abbe number among the lenses and can be 20 or less. The difference between the maximum refractive index and the minimum Abbe number can be 30 or greater. By maximizing the Abbe number of the third lens 403, which is positioned at the center of the optical system 1300, and minimizing the Abbe number of the sixth lens 406, which has a low refractive index and is adjacent to the image sensor 600, the dispersion of light traveling between the glass lens and the plastic lens can be controlled, and the dispersion between the glass lens and the plastic lens can be increased to guide the light toward the image sensor 600.

[0658] The Abbe number of each lens may satisfy any one of the following conditions.

[0659] Condition 1: v3 > v1 > v2, v4, v5, v6

[0660] Condition 2: v1, v3, v5 > v2 = v4 > v6

[0661] Condition 3: v3 > v1, v2, v4, v5, v6

[0662] Condition 4: v1, v3 > v5 > v2, v4, v6

[0663] The focal lengths (F1, F4, F6) of the first lens 401, the fourth lens 404, and the sixth lens 406 may have a negative (-) sign. The first lens 401, the fourth lens 404, and the sixth lens 406 may have a negative (-) refractive power. The focal lengths F2, F3, F5 of the second lens 402, the third lens 403, and the fifth lens 405 may have a positive (+) sign. The second lens 402, the third lens 403, and the fifth lens 405 may have a positive (+) refractive power. The second lens 402 and the third lens 403 having positive (+) refractive power may be placed on the sensor side of the first lens 401 having negative (-) refractive power. In this way, light incident from the object side can move away from the optical axis direction and then converge again toward the optical axis direction, thereby forming a stable optical path.

[0664] In addition, the fifth lens 405 and the sixth lens 406 , which are adjacently positioned lenses, may satisfy the following conditions.

[0665] Condition 1: The refractive index of the lens with positive refractive power < the refractive index of the lens with negative refractive power

[0666] Condition 2: Dispersion of a lens with positive refractive power > Dispersion of a lens with negative refractive power

[0667] Here, in the plastic lens, the fifth lens 405 has positive refractive power, and the sixth lens 206 has negative refractive power. Therefore, according to conditions 1 and 2, the refractive index of the fifth lens 405 is smaller than that of the sixth lens 406, and the dispersion value of the fifth lens 405 is larger than that of the sixth lens 406. Chromatic aberrations occurring in the plastic lens can be corrected by the plastic lens. In addition, since the fifth lens 405 and the sixth lens 406, as consecutively arranged plastic lenses, satisfy a refractive index difference of 0.1 or greater and 0.15 or less, and an Abbe number difference of 20 or greater and 50 or less, chromatic aberrations occurring in the plastic lens can be compensated by the plastic lens.

[0668] Optical systems have chromatic aberration, which is corrected by using a cemented lens or two lenses arranged in series. As the temperature changes from low to high, the lenses repeatedly contract and expand. Because the amount of change in lens characteristics due to temperature changes is the same for lenses made of the same material, correcting chromatic aberration between lenses made of the same material is effective even when the temperature fluctuates. Therefore, in the fourth embodiment of the present disclosure, chromatic aberration occurring in plastic lenses can be corrected by using the fifth lens 405 and the sixth lens 406.

[0669] When comparing focal lengths in absolute values, the focal length of the second lens 402 is the largest among the lenses and may be 10 or more and 20 or less. The focal length of the fourth lens 404 is the smallest among the lenses, and the absolute value of the focal length of the third lens 403 may be 3 or more and 5 or less.

[0670] The absolute value of the focal length of each lens may satisfy any one of the following conditions.

[0671] Condition 1: |f2|,|f3|,|f4|,|f5|,|f6|>|f1|>|f5|

[0672] Condition 2: |f2|>|f1|,|f3|,|f4|,|f5|,|f6|

[0673] Condition 3: |f2|,|f4|,|f6|>|f3|>|f1|,|f5|

[0674] Condition 4: |f2|,|f6|>|f4|>|f1|,|f3|,|f5|

[0675] Condition 5: |f1|,|f2|,|f3|,|f4|,|f6|>|f5|

[0676] Condition 6: |f2|>|f6|>|f1|,|f3|,|f4|,|f5|

[0677] The thickness T1 of the first lens 401 may be such that the difference between the maximum and minimum thicknesses is 1.5 times or greater, for example, within a range of 1.5 to 1.8 times. The thickness CT1 may be smallest at the center and the thickness ET1 may be largest at the edge. The thickness T2 of the second lens 402 may be such that the maximum thickness is 1 to 1.2 times the minimum thickness. The second lens 402 may have a maximum thickness CT2 at the center and a minimum thickness ET2 at the edge. The thickness T3 of the third lens 403 may be largest at the center and smallest at the edge, with the maximum thickness ranging from 1.2 to 1.5 times the minimum thickness. The thickness T4 of the fourth lens 404 may be smallest at the center and largest at the edge, with the maximum thickness ranging from 1.5 to 2 times the minimum thickness. The thickness T5 of the fifth lens 405 may be largest at the center and smallest at the edge, with the maximum thickness ranging from 2.5 to 3 times the minimum thickness. The thickness T6 of the sixth lens 406 may be smallest at the center and largest at the edge, with the maximum thickness ranging from 1 to 1.5 times the minimum thickness.

[0678] The thickness of each lens may satisfy any one of the following conditions.

[0679] Condition 1: 0.1 <CT1 / ET1<0.5,2<ET1 / CT1<2.5

[0680] Condition 2: 0.8 <CT2 / ET2<1.2,0.9<ET2 / CT2<1.3

[0681] Condition 3: 1.2 <CT3 / ET3<1.6,0.5<ET3 / CT3<1

[0682] Condition 4: 0.1 <CT4 / ET4<1,1.5<ET4 / CT4<2

[0683] Condition 5: 3 <CT5 / ET5<3.5,0.1<ET5 / CT5<0.5

[0684] Condition 6: 0.5 <CT6 / ET6<1,1.4<ET6 / CT6<1.8

[0685] Condition 7: 1 < ΣCT / ΣET < 1.5, 0.5 < ΣET / ΣCT < 1

[0686] Among the distances G1 to G6 between the lenses, the first distance G1 between the first lens 401 and the second lens 402 may have a maximum value at the center and a minimum value at the edge. The second distance G2 between the second lens 402 and the third lens 403 may have a maximum value at the edge and a minimum value at the center. The third distance G3 between the third lens 403 and the fourth lens 404 may have a maximum value at the edge and a minimum value at the center. The fourth distance G4 between the fourth lens 404 and the fifth lens 405 may have a maximum value at the center and a minimum value at the edge. The fifth distance G5 between the fifth lens 405 and the sixth lens 406 may have a maximum value at the center and a minimum value at the edge.

[0687] Figure 42 、 Figure 44 and Figure 46 It shows Figure 38 The graph is a graph of diffraction MTF (Modulation Transfer Function) at room temperature, low temperature and high temperature in the optical system of FIG. , and is a graph showing the brightness ratio (modulation) according to the spatial frequency. Figure 42 、 Figure 44 and Figure 46 As shown, in the fourth embodiment of the present disclosure, the deviation of the MTF at a low temperature or a high temperature based on room temperature may be less than 10%, that is, 7% or less.

[0688] Figure 43 、 Figure 45 and Figure 47 It shows Figure 38 The aberration characteristics of the optical system at room temperature, low temperature and high temperature are shown in the graph. Figure 43 、 Figure 45 and Figure 47 In the aberration curve diagram, longitudinal spherical aberration, astigmatism field curve and distortion are measured. Figure 43 、 Figure 45 and Figure 47 In FIG, the X-axis may represent the focal length (mm) and the degree of distortion (%), and the Y-axis may represent the height of the image. In addition, the graph for spherical aberration is a graph for light in wavelength bands of about 435 nm, about 486 nm, about 546 nm, about 587 nm, and about 656 nm, and the graph for astigmatism field curve and distortion is a graph for light in a wavelength band of about 546 nm. Figure 43 、 Figure 45 and Figure 47, it can be explained that the closer each curve at room temperature, low temperature, and high temperature is to the Y-axis, the better the aberration correction function is, and it can be seen that the optical system 1300 according to the fourth embodiment has measurement values ​​close to the Y-axis in almost all areas. In other words, the optical system 1300 according to the fourth embodiment has improved resolution and can have good optical performance not only in the center of the field of view (FOV) but also in the periphery. Here, the low temperature is -20 degrees or lower, for example, in the range of -20 degrees to -40 degrees, the room temperature is in the range of 22 degrees ± 5 degrees or in the range of 18 degrees to 27 degrees, and the high temperature can be 85 degrees or higher, for example, in the range of 85 degrees to 405 degrees. Therefore, it can be seen that at Figure 43 、 Figure 45 and Figure 47 The brightness ratio (modulation) from low temperature to high temperature decreases by less than 10%, for example, by less than 5%, or hardly changes.

[0689] The optical system of the fourth embodiment disclosed above can effectively control aberration characteristics such as chromatic aberration and distortion, and can have good optical performance not only in the center of the field of view (FOV_H) but also in the periphery.

[0690] The optical systems 1100, 1200, and 1300 according to the second to fourth embodiments disclosed above can satisfy at least one, two, or more of the mathematical expressions described below. Therefore, the optical systems 1100, 1200, and 1300 according to the second to fourth embodiments can have improved optical properties. For example, when the optical systems 1100, 1200, and 1300 satisfy at least one of the mathematical expressions, they can effectively control aberration characteristics such as chromatic aberration and distortion, and can exhibit good optical performance not only at the center of the field of view (FOV) but also at the periphery. Furthermore, the optical systems 1100, 1200, and 1300 can have improved resolution. The thickness of the lenses at the optical axis OA and the distance between adjacent lenses at the optical axis OA described in the mathematical expressions can refer to the second to fourth embodiments disclosed above.

[0691] [Mathematical expression 41]

[0692] 0.3<ΣCT / TTL<0.8

[0693] Mathematical expression 41 can set the relationship between the sum of the center thicknesses (ΣCT) of the first to sixth lenses 201 to 206, 301 to 306, 401 to 406 and TTL, where TTL is the distance (mm) from the center of the first surface S1 of the first lens 201, 301, 401 to the upper surface of the image sensor 600 on the optical axis OA. In order to reduce TTL, a large amount of light refraction must occur. In order to refract a large amount of light, the refractive power of the lens must increase, and in order to increase the refractive power, the lens becomes thicker. When it is less than the lower limit of mathematical expression 41, the sum of the lens thicknesses decreases and the refractive power weakens. When it exceeds the upper limit of mathematical expression 41, there is a problem that the sum of the lens thicknesses increases too much, resulting in an increase in TTL. In the second to fourth embodiments, mathematical expression 41 can preferably satisfy 0.4<ΣCT / TTL<0.7.

[0694] [Mathematical expression 42]

[0695] 0.1<ΣCG / TTL<0.5

[0696] Mathematical expression 42 can set the relationship between the sum of the distances between adjacent lenses (ΣCG) in the first to sixth lenses 201 to 206, 301 to 306, and 401 to 406 and TTL, where TTL is the distance (mm) from the center of the first surface S1 to the upper surface of the image sensor 600 on the optical axis OA. In order to reduce TTL, a large amount of light refraction must occur. In order to refract light in large quantities, the refractive power of the lens must be increased, and in order to increase the refractive power, the lens becomes thicker. When it is less than the lower limit of mathematical expression 42, the sum of the lens thicknesses becomes smaller, and the refractive power becomes less than the desired refractive power. If the upper limit of mathematical expression 42 is exceeded, there is a problem that the sum of the lens thicknesses increases too much, thereby increasing TTL. In the second to fourth embodiments, mathematical expression 42 can preferably satisfy 0.2<ΣCG / TTL<0.4.

[0697] [Mathematical expression 43]

[0698] 1<ΣCT / ΣCG<2.5

[0699] In Mathematical Expression 43, ΣCT is the sum of the lens center thicknesses, and ΣCG is the sum of the distances between adjacent lenses. When Mathematical Expression 43 is satisfied, the optical system can achieve excellent optical performance at a focal length within a given field of view, while also reducing TTL. In the second to fourth embodiments, Mathematical Expression 43 preferably satisfies 1.5 < ΣCT / ΣCG < 2.

[0700] [Mathematical expression 44]

[0701] 5<ΣIndex<15

[0702] In Mathematical Expression 44, ΣIndex refers to the sum of the refractive indices of the d-line of each of the multiple lenses. When Mathematical Expression 44 is satisfied, the TTL in the hybrid optical systems 1100, 1200, and 1300 of plastic and glass lenses can be controlled, and improved resolution can be achieved. In the second to fourth embodiments, Mathematical Expression 44 preferably satisfies 8<ΣIndex<12.

[0703] [Mathematical expression 45]

[0704] 20<ΣAbb / ΣIndex<30

[0705] In Mathematical Expression 45, ΣAbb refers to the sum of the Abbe numbers of each of the multiple lenses, and ΣIndex refers to the sum of the refractive indices of each of the multiple lenses at the d-line. If Mathematical Expression 45 is satisfied, the optical systems 1100, 1200, and 1300 can have improved aberration characteristics and resolution. By adjusting the sum of the Abbe numbers and the sum of the refractive indices of the lenses in Mathematical Expression 45, the optical characteristics can be controlled. In the second to fourth embodiments, Mathematical Expression 45 can preferably satisfy 20 < ΣAbb / ΣIndex < 25.

[0706] [Mathematical expression 46]

[0707] 0.1<ΣCT / ΣET<1

[0708] In Mathematical Expression 46, ΣCT is the sum of the central thickness of the lens, and ΣET is the sum of the edge thicknesses, that is, the sum of the end thicknesses of the lens' effective area. When Mathematical Expression 46 is satisfied, the optical system can achieve excellent optical performance at a focal length within a given field of view, while also reducing TTL. In the second to fourth embodiments, Mathematical Expression 46 preferably satisfies 0.4 < ΣCT / ΣET < 0.7.

[0709] [Mathematical expression 47]

[0710] 0.1 <CT1 / ET1<1

[0711] In mathematical expression 47, CT1 is the center thickness of the first lens 201, 301, 401, and ET1 is the edge thickness of the first lens 201, 301, 401. In this way, a factor affecting the field of view of the optical system can be set, and a factor affecting the effective focal length (EFL) can be set. In the second to fourth embodiments, mathematical expression 47 can preferably satisfy 0.3 <CT1 / ET1<0.6。

[0712] [Mathematical Expression 48]

[0713] 2 < CT5 / ET5 < 3.5

[0714] In Mathematical Expression 48, CT5 is the central thickness of the fifth lenses 105, 205, 305, and ET5 is the edge thickness of the fifth lenses 105, 205, 305. In this way, a factor affecting the field of view of the optical system can be set, and a factor affecting the effective focal length (EFL) can be set. In the second to fourth embodiments, Mathematical Expression 48 preferably satisfies 2 < CT5 / ET5 < 3.2.

[0715] [Mathematical Expression 49]

[0716] 0.5 < CT6 / ET6 < 1.5

[0717] In Mathematical Expression 49, CT6 is the central thickness of the sixth lenses 106, 206, 306, and ET6 is the edge thickness of the sixth lenses 106, 206, 306. In this way, a factor affecting the field of view of the optical system can be set, and a factor affecting the effective focal length (EFL) can be set. In the second to fourth embodiments, Mathematical Expression 49 preferably satisfies 0.5 < CT6 / ET6 < 1.2.

[0718] [Mathematical Expression 50]

[0719] 1 < GLCa_AVER / PLCa_AVER < 1.5

[0720] In Mathematical Expression 50, GLCa_AVER represents the average light transmission aperture of the glass lenses, and PLCa_AVER represents the average light transmission aperture of the plastic lenses. The lens barrel in which the lens part is arranged has at least one inner lens barrel in the lens barrel, and at least some of the plastic material lenses included in the lens part can be arranged in the inner lens barrel. In the case of plastic material lenses, due to a larger expansion amount at high temperatures, a wider space is required in the lens barrel. In Mathematical Expression 50, by setting the light transmission aperture sizes of the glass lenses and the plastic lenses, deterioration of optical characteristics due to temperature changes can be suppressed, and the optical systems 1100, 1200, 1300 can control incident light and set a factor affecting aberration. In the second to fourth embodiments, Mathematical Expression 50 preferably satisfies 1 < GLCa_AVER / PLCa_AVER < 1.2.

[0721] Here, nGL < nPL can be satisfied. nGL is the number of glass material lenses, and nPL is the number of plastic lenses. Additionally, the condition nPL - nGL = 0 or 1 can be satisfied.

[0722] [Mathematical expression 51]

[0723] 1.5 <CA_L1S1 / CA_L1S2<2.5

[0724] In mathematical expression 51, CA_L1S1 means the clear aperture of the first surface S1 of the first lens 201, 301, 401, and CA_L1S2 means the clear aperture of the second surface S2 of the first lens 201, 301, 401. When mathematical expression 51 is satisfied, degradation of optical characteristics due to temperature changes can be suppressed, and the optical systems 1100, 1200, 1300 can control incident light and set factors that affect aberrations. In the second to fourth embodiments, mathematical expression 51 can preferably satisfy 1.8 <CA_L1S1 / CA_L1S2<2.3。

[0725] [Mathematical expression 52]

[0726] 0.5 <CA_L1 / CA_L6<1.5

[0727] In mathematical expression 52, CA_L1 means the clear aperture of the first lens 201, 301, 401, and CA_L6 means the clear aperture of the sixth lens (106, 206, 306). The lens barrel in which the lens portion is arranged has at least one inner barrel in the lens barrel, and at least some of the plastic material lenses included in the lens portion can be arranged in the inner barrel. In the case of plastic material lenses, due to the large amount of expansion at high temperatures, a wider space is required in the lens barrel. Therefore, if the mathematical expression 52 setting the relationship between the clear aperture of the first lens 201, 301, 401 made of glass and the clear aperture of the sixth lens 106, 206, 306 made of plastic is satisfied, the deterioration of optical characteristics due to temperature changes can be suppressed, and the optical systems 1100, 1200, 1300 can control the incident light and set factors affecting aberrations. In the second to fourth embodiments, mathematical expression 52 can preferably satisfy 0.9 <CA_L1 / CA_L6<1.4。

[0728] [Mathematical expression 53]

[0729] 0.5 <CA_L1 / ImgH<1

[0730] Mathematical expression 53 can set the relationship between the size of the clear aperture (CA_L1) of the first lens 201, 301, 401 and the maximum diagonal length ImgH of the image sensor. If mathematical expression 53 is satisfied, the TTL applicable to the vehicle optical system is satisfied, and the set field of view can be satisfied. If it is less than the lower limit of mathematical expression 53, the clear aperture of the lens arranged in the optical system 1100, 1200, 1300 becomes the largest, and there is a problem that the TTL becomes longer. If it exceeds the upper limit of mathematical expression 53, there is a problem that the field of view becomes too large than the field of view satisfied by the optical system 1100, 1200, 1300. In the second to fourth embodiments, mathematical expression 53 can preferably satisfy 0.6 <CA_L1 / ImgH<0.9。

[0731] [Mathematical expression 54]

[0732] 0.5 <CT_Max / CG_Max<2

[0733] In mathematical expression 54, CT_Max is the maximum center thickness of the lens, and CG_Max is the maximum distance between adjacent lenses. When mathematical expression 54 is satisfied, the optical system can have good optical performance at the focal length in the set field of view and can reduce TTL. In the second to fourth embodiments, mathematical expression 54 can preferably satisfy 0.7 <CT_Max / CG_Max<1.7。

[0734] [Mathematical expression 55]

[0735] 2 <CA_max / CA_min<3

[0736] In mathematical expression 55, CA_max represents the largest clear aperture of the lens on the object side and the sensor side, and CA_Min represents the smallest clear aperture of the lens on the object side and the sensor side. When mathematical expression 55 is satisfied, the optical system can be sized for a slim and compact structure while maintaining optical performance. In the second to fourth embodiments, mathematical expression 55 can preferably satisfy 2.1 <CA_max / CA_min<2.5。

[0737] [Mathematical expression 56]

[0738] 1 <CA_max / CA_Aver<2

[0739] In mathematical expression 56, CA_max represents the largest clear aperture on the object side and the sensor side of the lens, and CA_Aver represents the average value of the clear apertures on the object side and the sensor side of the lens. When mathematical expression 56 is satisfied, the optical system can be sized for a slim and compact structure while maintaining optical performance. In the second to fourth embodiments, mathematical expression 56 can preferably satisfy 1.3 <CA_max / CA_Aver<1.6。

[0740] [Mathematical expression 57]

[0741] 0.5 <CA_min / CA_Aver<1

[0742] In Mathematical Expression 57, CA_Min represents the smallest clear aperture on the object side and the sensor side of the lens, and CA_Aver represents the average value of the clear apertures on the object side and the sensor side of the lens. If Mathematical Expression 57 is satisfied, the optical system can maintain optical performance and be sized for a slim and compact structure. In the second to fourth embodiments, Mathematical Expression 57 can preferably satisfy 0.5 <CA_min / CA_Aver<0.8。

[0743] [Mathematical expression 58]

[0744] 0.1 <CA_max / ImgH<1

[0745] In mathematical expression 58, CA_max represents the largest clear aperture of the lens on the object side and the sensor side, and Imgh represents the maximum diagonal length of the image sensor 600. If mathematical expression 58 is satisfied, the optical system can maintain good optical performance and be sized for a slim and compact structure. In the second to fourth embodiments, mathematical expression 58 can preferably satisfy 0.5 <CA_max / ImgH<1。

[0746] [Mathematical expression 59]

[0747] 10 <TTL<15

[0748] In Mathematical Expression 59, TTL (Total Track Length) means the distance (mm) from the center of the first surface S1 of the first lens 201, 301, 401 to the upper surface of the image sensor 600 on the optical axis OA. When Mathematical Expression 59 is satisfied, a suitable vehicle optical system can be provided. In the second to fourth embodiments, Mathematical Expression 59 can preferably satisfy 12 <TTL<14。

[0749] [Mathematical expression 60]

[0750] 5 < ImgH < 9

[0751] In mathematical expression 60, ImgH means the maximum diagonal length of image sensor 600. Mathematical expression 60 can set the diagonal size (ImgH) of image sensor 600 and can provide an optical system with a vehicle sensor size. In the second to fourth embodiments, mathematical expression 60 can preferably satisfy 6 < ImgH < 8.

[0752] [Mathematical expression 61]

[0753] 1 < BFL < 3

[0754] In mathematical expression 61, BFL is the distance along the optical axis from image sensor 600 to the center of the sensor side of the last lens. When mathematical expression 61 is satisfied, the installation space for filter 500 and cover glass can be ensured, and the assembly of components can be improved by the distance between image sensor 600 and the last lens, and the bonding reliability can be increased. In the second to fourth embodiments, mathematical expression 61 can preferably satisfy 1 < BFL < 2.6. When BFL is less than the range of mathematical expression 61, some of the light traveling to the image sensor may not be transmitted to the image sensor, resulting in a reduction in resolution. When BFL exceeds the range of mathematical expression 61, stray light is introduced, which deteriorates the aberration characteristics of the optical system.

[0755] [Mathematical expression 62]

[0756] 2 < F < 5

[0757] Mathematical expression 62 can set the total focal length F suitable for the vehicle optical system. In the second to fourth embodiments, mathematical expression 62 can satisfy 2 < F < 3.

[0758] [Mathematical expression 63]

[0759] 130 < FOV < 170

[0760] In mathematical expression 63, FOV (field of view) means the field of view (degrees) of optical systems 1100, 1200, 1300 and can provide a field of view suitable for the vehicle optical system. In the second to fourth embodiments, FOV can preferably satisfy 145 < FOV < 160. <​​​​​​In mathematical expression 64, CA_max means the largest clear aperture (mm) of the object side and the sensor side of the plurality of lenses, and TTL (total track length) means the distance (mm) from the vertex of the first surface S1 of the first lens 201, 301, 401 to the upper surface of the image sensor 600 on the optical axis OA. Mathematical expression 64 sets the relationship between the total optical axis length and the maximum clear aperture of the optical system, thereby providing an improved vehicle optical system. In the second to fourth embodiments, mathematical expression 64 may preferably satisfy 2 <TTL / CA_max<2.5。

[0764] [Mathematical Expression 65]

[0765] 1.5 <TTL / ImgH<2.5

[0766] Mathematical expression 65 means that TTL (Total Track Length) means the distance (mm) from the vertex of the first surface S1 of the first lens to the upper surface of the image sensor 600 on the optical axis OA, and ImgH means the maximum diagonal length of the image sensor 600. When mathematical expression 65 is satisfied, the optical systems 1100, 1200, and 1300 can have TTL applied to the vehicle image sensor 600, thereby providing improved image quality. In the second to fourth embodiments, mathematical expression 65 can preferably satisfy 1.5 <TTL / ImgH<2。

[0767] [Mathematical Expression 66]

[0768] 0.1 <BFL / ImgH<1

[0769] Mathematical expression 66 means that BFL is the optical axis distance from the image sensor 600 to the center of the sensor side of the last lens, and ImgH means the maximum diagonal length of the image sensor 600. When mathematical expression 66 is satisfied, the optical systems 1100, 1200, and 1300 can ensure a BFL (back focal length) of the size of the image sensor 600 for the application vehicle, can set the distance between the last lens and the image sensor 600, and can have good optical characteristics at the center and periphery of the field of view (FOV). In the second to fourth embodiments, mathematical expression 66 can preferably satisfy 0.1 <BFL / ImgH<0.5。

[0770] [Mathematical Expression 67]

[0771] 5 <TTL / BFL<15

[0772] Mathematical expression 67 means that TTL (Total Track Length) is the distance (mm) from the vertex of the first surface S1 of the first lens 201, 301, 401 to the upper surface of the image sensor 600 on the optical axis OA, and BFL means the optical axis distance from the image sensor 600 to the center of the sensor side of the last lens. When mathematical expression 67 is satisfied, the optical systems 1100, 1200, and 1300 can ensure BFL. In the second to fourth embodiments, mathematical expression 67 can preferably satisfy 5 <TTL / BFL<12。

[0773] [Mathematical expression 68]

[0774] 5 <TTL / F<8

[0775] Mathematical expression 68 means that TTL (total track length) is the distance (mm) from the vertex of the first surface S1 of the first lens to the upper surface of the image sensor 600 on the optical axis OA, and F is the effective focal length of the optical system. Therefore, an optical system for a driver assistance system can be provided. When the optical systems 1100, 1200, 1300 according to the embodiments satisfy mathematical expression 68, the optical systems 1100, 1200, 1300 can have an appropriate focal length within the set TTL range, and provide an optical system that can form an image while maintaining an appropriate focal length even when the temperature changes from a low temperature to a high temperature. If it is less than the lower limit of mathematical expression 68, the refractive power of the lens must be increased, making it difficult to correct spherical aberration or distortion, and if it exceeds the upper limit of mathematical expression 68, the clear aperture or TTL of the lens becomes longer, so that there may be a problem that the shooting lens system becomes larger. In the second to fourth embodiments, mathematical expression 68 can preferably satisfy 5 <TTL / F<6.5。

[0776] [Mathematical Expression 69]

[0777] 0.5 <F / BFL<2

[0778] In mathematical expression 69, F is the effective focal length of the optical system, and BFL means the optical axis distance from the image sensor 600 to the center of the sensor side of the last lens. If mathematical expression 69 is satisfied, the optical systems 1100, 1200, 1300 can have a set field of view and an appropriate focal length, and a vehicle optical system can be provided. In addition, the optical systems 110, 1200, 1300 can minimize the distance between the last lens and the image sensor 600, so that they can have good optical characteristics at the periphery of the field of view (FOV). In the second to fourth embodiments, mathematical expression 69 can preferably satisfy 0.5 <F / BFL<1.8。

[0779] [Mathematical expression 70]

[0780] 0.1 <F / ImgH<1

[0781] In the mathematical expression 70, F is the effective focal length of the optical system, and ImgH means the maximum diagonal length of the image sensor 600. Such optical systems 110, 1200, 1300 can have improved aberration characteristics in the size of the vehicle image sensor 600. In the second to fourth embodiments, the mathematical expression 70 can preferably satisfy 0.1 <F / ImgH<0.5。

[0782] [Mathematical expression 71]

[0783]

[0784] In Mathematical Expression 71, Z may refer to the distance from any position on the aspheric surface to the vertex of the aspheric surface having sag along the optical axis. Y may refer to the distance from any position on the aspheric surface to the optical axis in a direction perpendicular to the optical axis. c may refer to the curvature of the lens, and K may refer to the conic constant. In addition, A, B, C, D, E, and F may refer to aspheric coefficients.

[0785] The optical systems 1100, 1200, and 1300 according to the second to fourth embodiments may satisfy at least one or two or more of the mathematical expressions 41 to 71. In this case, the optical systems 1100, 1200, and 1300 may have improved optical characteristics. Specifically, when the optical systems 1100, 1200, and 1300 satisfy at least one or more of the mathematical expressions 41 to 71, the optical systems 1100, 1200, and 1300 may have improved resolution and may improve aberration and distortion characteristics. In addition, the optical systems 110, 1200, and 1300 may ensure a BFL (back focal length) suitable for the application of the vehicle image sensor 600, may compensate for degradation of optical characteristics due to temperature changes, and may minimize the distance between the last lens and the image sensor 600, thereby achieving good optical performance at the center and periphery of the field of view (FOV).

[0786] Table 22 shows the result values ​​for the above-mentioned mathematical expressions 41 to 70 in the optical systems 1100, 1200, and 1300 according to the embodiment. Referring to Table 22, it can be seen that the optical systems 1100, 1200, and 1300 satisfy at least one, two or more, or three or more of the mathematical expressions 41 to 70. In detail, it can be seen that the optical systems 1100, 1200, and 1300 according to the embodiment satisfy all of the mathematical expressions 41 to 70. Therefore, the optical systems 1100, 1200, and 1300 can have good optical performance at the center and periphery of the field of view (FOV) and can have excellent optical characteristics.

[0787] [Table 22]

[0788]

[0789]

[0790] In the following, reference is made to Figures 50 to 56 In the present embodiment, a camera module that adjusts the distance between lenses or the distance between a lens and an image sensor according to temperature changes in an optical system will be described. The camera module according to the present embodiment can minimize performance changes according to temperature.

[0791] Reference Figure 50 According to this embodiment, the camera system may include a camera module 11000, a temperature compensation part 211 that provides a driving signal to the camera module 11000, a temperature sensor 213 that detects the ambient temperature of the camera module 11000, and a storage part 215 that stores a compensation rate according to temperature changes.

[0792] The driving portion 140 may be implemented as a first driving portion 141 that moves one lens of the second lens holder 1030 in the direction of the optical axis Lz. As another example, the driving portion 140 may be implemented as a second driving portion 151 that moves the main board 700 in the direction of the optical axis Lz.

[0793] As another example, the driving section 140 may be implemented as a third driving section 161 that moves one lens of the first lens holder 1010 in the direction of the optical axis Lz. The driving section 140 may be implemented as a single driving section, but as another example, may be implemented as two or more driving sections, for example, as a first driving section 141 and a second driving section 151, as a first driving section 141 and a third driving section 161, or as a second driving section 151 and a third driving section 161.

[0794] The actuator may be a VCM (Voice Coil Motor) type drive having a magnet and a coil, and may further include a support member, and a yoke or / and a Hall sensor may be arranged outside the magnet.

[0795] The camera module 11000 may be configured such that a plurality of lenses 101, 102, and 103 may be stacked along the optical axis Lz from the object side toward the sensor side. The stack may include, for example, a first lens 101, a second lens 102, and a third lens 103. The first lens 101 may be the lens closest to the object side or the first lens. The third lens 103 may be defined as the lens closest to the sensor or the last lens.

[0796] The camera module 11000 may be configured with only a plastic lens. When a plastic lens is used in a vehicle, the price can be reduced compared to a glass lens, and the incident side surface and the output side surface can be set to an aspherical surface so that light path control can be facilitated. Here, the coefficient of thermal expansion (CTE) of the plastic material can be 5 times higher than that of the glass material, and the change value of the refractive index as a function of temperature can be 10 times lower than that of the glass material. In the case where the expansion and contraction according to temperature are relatively large, for example, in a plastic lens, as in Figure 51 In (A) and (B), plastic lenses 111 and 112 can expand or contract according to temperature changes. For example, when the object side is convex and / or the sensor side is concave, as in (A), they can expand toward the object side. And when the object side is concave and / or the sensor side is convex, as in (B), they can expand toward the sensor side. These lenses 111 and 112 can have different positions of the incident and output side surfaces or the height of the optical axis Lz. Therefore, lenses 111 and 112 can affect optical characteristics according to temperature changes.

[0797] For heat dissipation efficiency, the first lens holder 1010 can be made of a plastic material or a metal material. For heat dissipation efficiency, the second lens holder 1030 can be made of a plastic material or a metal material. If the lens holders 1010 and 1030 are made of metal, they can improve the heat dissipation effect of the camera module 11000, or if they are made of the same material as the plastic lens, they can reduce the difference in thermal expansion coefficient. The metal material can be selected from, for example, Al, Ag, or Cu, and can be Al or an Al alloy. A hydrophilic material can be coated or applied to the surfaces of the first lens holder 101 and the second lens holder 103. In an embodiment of the present disclosure, the material of the second lens holder 1030 can be made of metal to compensate for the BFL.

[0798] Each of lenses 101, 102, and 103 may include an active region having a clear aperture through which light enters, and a flange serving as an inactive region outside the active region. The inactive region may be an area where light is blocked by light shielding portions 131 and 133. The flange may extend circumferentially relative to the optical axis Lz within the active regions of lenses 101, 102, and 103. At least one of lenses 101, 102, and 103 may not have a flange portion or may have a relatively short length. The third lens 103 may have a flange 117A on its outer periphery, which may be coupled to the inner side of the second lens holder 1030.

[0799] The temperature sensor 213 can detect the ambient temperature of the camera module 11000. The detected temperature can be the temperature inside or outside the camera module 11000, and can detect temperatures within a range of -50°C to 125°C. The camera module 11000 can be used in mobile devices such as vehicles, aircraft, ships, or portable terminals. For example, when used in a vehicle, the temperature may vary significantly due to the external environment. In this case, the reference temperature may be the temperature inside the vehicle.

[0800] The temperature compensating part 211 controls the driving mode of the driving part based on the temperature detected by the temperature sensor 213. The storing part 215 may match and store the detected temperature and the temperature compensation rate based on the temperature.

[0801] For example, Figure 53As shown, the temperature compensation rate of the zone segments can be set to a first mode (states 1 to 3) based on the reference temperature, which is used to compensate when the temperature is lower than the reference (Ref) temperature; and a second mode (states 5 to 8) which is used to compensate when the temperature is higher than the reference (Ref) temperature. The reference (Ref) temperature can be an indoor temperature, for example, in the range of 10 degrees to 30 degrees or in the range of 15 degrees to 25 degrees, and preferably 20 degrees ± 10 degrees. The first mode (states 1 to 3) is a temperature lower than the reference (Ref) temperature, and the temperature of each segment can be divided into at least three segments ranging from 10 degrees to -50 degrees, and the first segment (state 1) can be in the range of 10 degrees to -10 degrees, the second segment (state 2) can be in the range of -10 degrees to -30 degrees, and the third segment (state 3) can be in the range of -30 degrees to -50 degrees. The reference temperature of each of the first to third sections (states 1 to 3) can be 0 degrees, -20 degrees, and -40 degrees, and the temperature deviation of each section can be ±10 degrees. The second mode is a temperature higher than the reference (Ref) temperature, and the temperature of the subsection can be divided into at least four sections from 30 degrees to 100 degrees, and the subsection observation temperature, the first section (state 5) has a range of 30 degrees to 50 degrees, the second section (state 6) has a range of 50 degrees to 70 degrees, the third section (state 7) has a range of 70 degrees to 90 degrees, and the fourth section (state 8) can be a range of 90 degrees to 110 degrees. The reference temperature of the subsections of the first to fourth sections (states 5 to 8) can be 40 degrees, 60 degrees, 80 degrees, and 100 degrees, and the temperature deviation of the subsection can be ±10 degrees.

[0802] Another example of the present disclosure is that the temperature compensation rate of each section can be compensated by the average temperature change of each section (states 1 to 8). For example, in the first section (state 1) below the reference temperature, the temperature compensation rate can be set to the average of the temperature compensation rate of 10 degrees and the temperature compensation rate of -10 degrees, and in this way, the average temperature compensation rate of each section in the second to third sections below the reference temperature can be set. In addition, in the first section (state 5) above the reference temperature, the temperature compensation rate of the section can be set to the average of the temperature compensation rate of 30 degrees and the temperature compensation rate of 50 degrees, and in this way, the average temperature compensation rate of each section in the second to fourth sections above the reference temperature can be compensated.

[0803] Another example of the present disclosure is that when calculating the average temperature compensation rate, in each segment below the reference temperature, more weight can be given to the compensation rate of the relatively low temperature, and in each segment above the reference temperature, more weight can be given to the compensation rate of the relatively high temperature. For example, in the first segment below the reference temperature (state 1), the temperature compensation rate of 10 degrees can be given a weight of 30%, the temperature compensation rate of -10 degrees can be given a weight of 70%, and the temperature compensation rate can be set to the average of these, and in this way, the average temperature compensation rate with added weight can be set for each segment from the second segment to the third segment below the reference temperature. In addition, in the first segment above the reference temperature (state 5), the temperature compensation rate of 30 degrees can be given a weight of 30%, and the temperature compensation rate of 50 degrees can be given an additional weight of 70%, and the temperature compensation rate of the corresponding segment can be set to the average of these, and in this way, each segment from the second segment to the fourth segment above the reference temperature can be compensated using the average temperature compensation rate.

[0804] The temperature compensation portion 211 may determine a driving mode with a matching temperature by comparing the detected temperature with a reference pattern, a temperature compensation rate of each segment (states 1 to 3) of the first mode, and a temperature compensation rate of each segment (states 1 to 3) in the second mode stored in the storage portion 215. Alternatively, the temperature compensation portion 211 may control the position of the BFL based on an average temperature compensation rate of each segment.

[0805] The temperature compensation unit 211 can control at least one of the driving units 141, 151, and 161 according to the driving mode. For example, when the first driving unit 141 is driven by the first control signal F1, the optical axis Lz distance between the sensor side of the third lens 103 and the image sensor 600, namely, the back focus (BFL), can increase or decrease. Preferably, since the third lens 103 contracts or expands according to temperature changes, the reference BFL can decrease or increase.

[0806] In one section, the third lens 103 may contract, thereby increasing the BFL from a reference value, and the temperature compensation unit 211 may control the driving units 141 and 151 to increase the BFL according to the temperature compensation rate of the BFL. Conversely, in a section of the second mode where the detected temperature is higher than the reference temperature, the third lens 103 may expand, which causes the BFL to decrease from the reference value, and the temperature compensation unit 211 may control the first driving units 141 and 151 to decrease the BFL according to the temperature compensation rate of the BFL.

[0807] When the first control signal F1 is input, the first drive section 141 can move the third lens 103 upward or downward along the optical axis Lz. When the second control signal F2 is input, the second drive section 151 can move the main board 700 upward or downward along the optical axis Lz. When the third control signal F3 is input, the third drive section 161 can move the first lens holder 1010 or any of the internal lenses 101, 102, 103 upward or downward along the optical axis Lz. Here, when the third drive section 161 is driven, the change in the total track length (TTL) of the camera module 11000 can be controlled according to temperature changes, or the TTL can be reduced or increased according to changes in the backlight fuse (BFL). The TTL is the distance from the object side of the first lens 101 to the optical axis Lz of the image sensor 600.

[0808] like Figure 54 As shown, embodiments of the present disclosure drive the first drive unit 141 or the second drive unit 151 to increase or decrease the BFL according to temperature changes or BFL changes of the last lens 300 within the following region: a point connecting the minimum -5% and maximum -14.3% when the temperature is as low as -40 degrees Celsius, and a point connecting the minimum 5% and minimum 14.3% when the temperature is as high as 100 degrees Celsius, thereby maintaining a constant reference BFL. Therefore, changes in the optical performance of the camera module due to temperature changes can be suppressed.

[0809] When a control signal based on the temperature detected by temperature compensator 211 is input, first actuator 141A and second actuator 141B cause magnet 41 to move upward or downward along optical axis Lz along with second lens holder 1030 due to the electromagnetic interaction between coil 42 and magnet 41. At this time, spring member 45 supports movement of second lens holder 1030 in the direction of optical axis Lz, and the optical axis distance (BFL) between lens L3 of second lens holder 1030 and image sensor 600 increases or decreases. Therefore, even if the last lens L3 expands or contracts due to temperature, the distance (BFL) between the last lens L3 of second lens holder 1030 and image sensor 600 can be kept constant. Consequently, even if the temperature varies depending on the configuration, camera module 11000 can suppress changes in optical performance.

[0810] Reference Figure 56The BFL compensation method of the temperature compensation part 211 detects the ambient temperature of the camera module 11000 through the temperature sensor 213 (S1), and compares and matches the detected ambient temperature with the temperature compensation table stored in the storage part 215 (S2). At this time, if the ambient temperature is in the reference mode, it is controlled to be maintained at the reference BFL (S3), and if the first temperature is lower than the reference temperature, a driving force is provided to the first driving part 141 or the second driving part 151 of the camera module to increase the BFL (S4), and if the second temperature is higher than the reference temperature, a driving force is provided to the first driving part 141 or the second driving part 151 of the camera module to reduce the BFL (S5).

Claims

1. An optical system comprising: The first to sixth lenses are arranged along the optical axis, The first lens has negative (-) refractive power. The second lens has positive (+) refractive power. Among them, the third lens has positive (+) refractive power, Among them, the fourth lens has negative (-) refractive power, Among them, the fifth lens has positive (+) refractive power, Among them, the sixth lens has negative (-) refractive power, wherein an aperture is arranged between the second lens and the third lens, and Among the distances between adjacent lenses on the optical axis, the distance between the first lens and the second lens is the largest.

2. The optical system according to claim 1, in, At least one of the first lens and the third lens is made of glass, and At least one of the second lens, the fourth lens and the fifth lens is made of plastic.

3. The optical system according to claim 1, in, The second lens among the first to sixth lenses has the largest thickness along the optical axis.

4. The optical system according to claim 1, in, The second lens has a meniscus shape that is convex toward the sensor.

5. The optical system according to claim 1, in, The fifth lens has convex surfaces on both sides.

6. The optical system according to claim 1, in, The sixth lens has a meniscus shape that is convex toward the sensor.

7. The optical system according to any one of claims 1 to 6, in, The following conditional expressions are satisfied, <conditional expression> 10 <TTL<15, (In the above conditional expressions, TTL refers to the distance from the object side of the first lens to the upper surface of the image sensor on the optical axis).

8. The optical system according to any one of claims 1 to 6, in, The following conditional expressions are satisfied, <conditional expression> 0.3<ΣCT / TTL<0.8, (In the above conditional expressions, ΣCT refers to the sum of the center thicknesses of the first to sixth lenses, and TTL refers to the distance from the object side of the first lens to the upper surface of the image sensor on the optical axis).

9. The optical system according to any one of claims 1 to 6, in, The following conditional expressions are satisfied, <conditional expression> 0.5 <CA_L1 / CA_L6<1.5, (In the above conditional expressions, CA_L1 refers to the clear aperture of the first lens, and CA_L6 refers to the clear aperture of the sixth lens).

10. An optical system comprising: The first to sixth lenses are arranged along the optical axis, The second lens has positive (+) refractive power. Among them, the fourth lens has negative (-) refractive power, Among them, the fifth lens has positive (+) refractive power, Among them, the sixth lens has negative (-) refractive power, Among the first to sixth lenses, the second lens has the largest thickness on the optical axis. Wherein, the fifth lens has a convex shape on both sides, and The sixth lens has a meniscus shape that is convex toward the sensor side.

Images