Camera module and vehicle equipped with same

Abstract

A camera module disclosed in an embodiment of the invention includes a lens barrel having a through hole therein, a lens unit having first to third lenses disposed in the through hole of the lens barrel and having optical axes aligned from an object side to a sensor side, and an image sensor, wherein the material of the second lens is different from the material of the first lens, the refractive index of the second lens is lower than the refractive index of the first lens, and each of the first to third lenses includes first to third flange portions extending from the optical axis toward an inner surface of the lens barrel, an outer diameter of the lens barrel at a position where an upper portion of the first flange portion contacts the lens barrel is a first outer diameter, an outer diameter of the lens barrel at a position where an upper portion of the second flange portion contacts the lens barrel is a second outer diameter, an outer diameter of the lens barrel at a position where an upper portion of the third flange portion contacts the lens barrel is a third outer diameter, and an outer diameter of the lens barrel at a position where an upper portion of the image sensor contacts the lens barrel is a fourth outer diameter, and the third outer diameter may be smaller than the fourth radius and larger than the second outer diameter.

Description

[Technical Field]

[0001] An embodiment of the invention relates to a camera module and a vehicle equipped therewith. [Background technology]

[0002] ADAS (Advanced Driving Assistance System) is an advanced driving assistance system that assists drivers in driving. It senses the situation ahead, determines the situation based on the sensing results, and controls the vehicle's movement based on the situation determination. For example, an ADAS sensor device detects vehicles ahead and recognizes lanes. After determining the target lane, target speed, and forward targets, the vehicle's Electrical Stability Control (ESC), Engine Management System (EMS), Motor Driven Power Steering (MDPS), etc. are controlled. Typically, ADAS is implemented as an automatic parking system, a low-speed city driving assistance system, a blind spot warning system, etc. Sensor devices for detecting the situation ahead in ADAS include GPS sensors, laser scanners, forward radar, LiDAR, etc., but the most representative is a front camera for capturing images of the area ahead of the vehicle.

[0003] The driver condition monitoring system consists of a near-infrared (NIR) camera and an electronic control unit (ECU). The system uses an NIR LED to project infrared light onto the driver's face and captures an image of the driver's face illuminated by the infrared light. The ECU processes the image of the driver's face captured by the NIR camera to detect the eyes, nose, and mouth, and checks the direction the driver is looking and whether their eyes are open or closed. The ECU can determine the driver's condition based on the direction the driver is looking and whether their eyes are open or closed, and thereby determine whether the driver is not paying attention to the road ahead. If the ECU determines that the driver is not paying attention to the road ahead, it will issue a warning signal to the driver via an output device such as a buzzer.

[0004] Recently, research into detection systems that sense the surroundings of a vehicle has been accelerating for the safety and convenience of drivers. Vehicle detection systems are used for a variety of purposes, such as detecting objects around a vehicle to prevent collisions with objects that the driver could not see, as well as detecting open spaces and enabling automatic parking, and provide essential data for automatic vehicle control. Such detection systems typically use radar signals or cameras. Vehicle camera modules are built into front and rear monitoring cameras and black boxes in automobiles to capture photos and videos of objects. Since vehicle camera modules are exposed to the outside, the image quality can deteriorate depending on humidity and temperature. In particular, camera modules have the problem of their optical characteristics changing depending on the ambient temperature and lens material. Summary of the Invention [Problem to be solved by the invention]

[0005] Embodiments of the invention can provide a camera module with a novel lens optics.

[0006] An embodiment of the invention can provide a camera module with a novel lens barrel.

[0007] An embodiment of the invention can provide a camera module having an optical system with at least one thermally compensated lens among its lenses and a lens barrel for suppressing thermal distortion.

[0008] An embodiment of the invention can provide a camera module for reducing thermal deformation due to contact characteristics between a flange portion of at least one of the lenses and an inner wall of the lens barrel.

[0009] Embodiments of the invention can provide mobile devices, such as mobile terminals and vehicles, with camera modules. [Means for solving the problem]

[0010] A camera module according to an embodiment of the invention includes a lens barrel including a through hole, and a lens unit disposed inside the through hole and including a first lens, a second lens, and a third lens, wherein the lens barrel includes a first inner wall, a second inner wall, and a third inner wall inside the through hole, the first lens contacts the first inner wall, the second lens contacts the second inner wall, and the third lens contacts the third inner wall, the first lens comprises a glass material, and the second lens and the third lens comprise a plastic material, the diameter of the first lens is 5 mm or less, the diameters of the second lens and the third lens are 10 mm or less, and the linear expansion coefficient of the lens barrel is 31 ppm / °C to 60 ppm / °C.

[0011] According to an embodiment of the invention, the first lens, the second lens, and the third lens include an effective area where light is incident and an ineffective area where light is not incident, and the diameter of the first lens, the diameter of the second lens, and the diameter of the third lens are defined as the sum of the effective area and the ineffective area.

[0012] According to an embodiment of the invention, the linear expansion coefficient of the lens barrel is greater than that of the first lens and is less than or equal to that of the second lens and the third lens. The linear expansion coefficient of the first lens is greater than 0 ppm / °C to 20 ppm / °C, the linear expansion coefficient of the second lens is 5 ppm / °C to 60 ppm / °C, and the linear expansion coefficient of the third lens is 5 ppm / °C to 60 ppm / °C.

[0013] According to another example of the invention, the diameter of the first lens is 3 mm to 5 mm, the diameters of the second lens and the third lens are 3 mm to 9 mm, and the diameter of the first lens is smaller than the diameters of the second lens and the third lens. According to an embodiment of the invention, the linear expansion coefficient of the first lens is greater than 0 ppm / °C to 10 ppm / °C, the linear expansion coefficient of the second lens is 50 ppm / °C to 60 ppm / °C, and the linear expansion coefficient of the third lens is 50 ppm / °C to 60 ppm / °C.

[0014] In the camera module according to the embodiment, the diameter of the first lens is 3.2 mm to 4.4 mm, the diameters of the second lens and the third lens are 4.5 mm to 8 mm, and the diameter of the first lens is smaller than the diameters of the second lens and the third lens. The linear expansion coefficient of the lens barrel is 29 ppm / °C to 50 ppm / °C or 39 ppm / °C to 60 ppm / °C.

[0015] According to an embodiment of the invention, the camera module is driven in a first mode in which a temperature changes from a first temperature to a second temperature higher than the first temperature, and a second mode in which a temperature changes from the first temperature to a third temperature lower than the first temperature, wherein in the first mode, a distance between the first lens and the first inner wall is 15 μm or less, in the second mode, a distance between the second lens and the second inner wall is 6 μm or less, and in the second mode, a distance between the third lens and the third inner wall is 6 μm or less, the first temperature is 20°C to 30°C, the second temperature is 80°C to 105°C, and the third temperature is -40°C to -30°C.

[0016] A camera module according to another embodiment of the invention includes a barrel including a through-hole, and a lens unit disposed inside the through-hole and including a first lens, a second lens, and a third lens, the lens barrel including a first inner wall, a second inner wall, and a third inner wall inside the through-hole, the first lens contacting the first inner wall, the second lens contacting the second inner wall, and the third lens contacting the third inner wall, the first lens expanding in a first mode changing from a first temperature to a second temperature higher than the first temperature, and the second lens and the third lens expanding in a first mode changing from the first temperature to the third temperature lower than the first temperature. a first temperature of 20°C to 30°C, a second temperature of 80°C to 105°C, and a third temperature of -40°C to -30°C.

[0017] According to an embodiment of the invention, the first lens includes glass, and the second and third lenses include plastic, and the linear expansion coefficient of the lens barrel is greater than that of the first lens and is less than or equal to that of the second and third lenses.

[0018] According to another embodiment of the invention, the linear expansion coefficient of the first lens is greater than 0 ppm / °C and greater than 20 ppm / °C, the linear expansion coefficient of the second lens is between 5 ppm / °C and 60 ppm / °C, the linear expansion coefficient of the third lens is between 5 ppm / °C and 60 ppm / °C, the diameter of the first lens is between 3 mm and 5 mm, the diameters of the second lens and the third lens are between 3 mm and 9 mm, and the diameter of the first lens is smaller than the diameters of the second lens and the third lens.

[0019] According to another embodiment of the invention, the linear expansion coefficient of the first lens is greater than 0 ppm / °C and less than 20 ppm / °C, the linear expansion coefficient of the second lens is between 50 ppm / °C and 60 ppm / °C, the linear expansion coefficient of the third lens is between 50 ppm / °C and 60 ppm / °C, the diameter of the first lens is between 3.2 mm and 4.4 mm, the diameters of the second lens and the third lens are between 4.5 mm and 8 mm, and the diameter of the first lens is smaller than the diameters of the second lens and the third lens.

[0020] According to another embodiment of the invention, the linear expansion coefficient of the lens barrel is 29 ppm / °C to 50 ppm / °C or 39 ppm / °C to 60 ppm / °C.

[0021] According to another embodiment of the invention, in the first mode, the difference between the expansion amount of the lens barrel and the expansion amount of the first lens (barrel expansion amount - first lens expansion amount) is 18 μm or less, and in the second mode, the difference between the contraction amount of the second lens or third lens and the contraction amount of the lens barrel (second or third lens contraction amount - barrel contraction amount) is 9 μm or less.

[0022] According to another embodiment of the present invention, there is provided a camera module including a lens barrel having a through hole, and a lens unit disposed inside the through hole and including a first lens, a second lens, and a third lens, wherein the lens barrel includes a first inner wall, a second inner wall, and a third inner wall inside the through hole, the first lens includes glass, and the second lens and the third lens include plastic materials, and a diameter of at least one of the first lens, the second lens, and the third lens satisfies the following formula:

[0023] Formula: 2 mm ≦ lens diameter ≦ {40 μm / (barrel linear expansion coefficient (ppm / ℃) - lens linear expansion coefficient (ppm / ℃)) × temperature change (℃)} According to another embodiment of the present invention, there is provided a camera module including a lens barrel having a through hole, and a lens unit disposed inside the through hole and including a first lens, a second lens, and a third lens, wherein the lens barrel includes a first inner wall, a second inner wall, and a third inner wall inside the through hole, the first lens comprises a glass material, the second lens and the third lens comprise a plastic material, and a diameter of at least one of the first lens, the second lens, and the third lens satisfies the following formula:

[0024] Formula: 2mm≦Lens diameter≦{Lens decenter size (μm) / (Barrel linear expansion coefficient (ppm / ℃) - Lens linear expansion coefficient (ppm / ℃)) × Temperature change (℃)} [Effects of the Invention]

[0025] According to an embodiment of the invention, it is possible to reduce thermal deformation or temperature-induced shape changes due to material differences between lenses in a camera module.

[0026] According to an embodiment of the present invention, the lens barrel disposed around the lens in the camera module can be provided with a constant thickness, thereby reducing thermal deformation or shape change of the lens due to temperature.

[0027] According to embodiments of the invention, a camera module having a mechanically thermally compensated lens and lens barrel can be provided to improve the reliability of the camera module.

[0028] According to an embodiment of the invention, the contact position and / or contact area of ​​the plastic lens with the lens barrel can be adjusted to suppress thermal deformation, thereby improving the reliability of the camera module.

[0029] According to an embodiment of the invention, by taking into consideration the contact characteristics between the lens flange and the inner surface of the lens barrel, it is possible to suppress changes in optical characteristics due to expansion and contraction of the lens in a direction perpendicular to the optical axis. The embodiment of the invention suppresses changes in the shape of the lens, which is optically sensitive to thermal changes, and can suppress the problem of the lens optical axis shifting and a sudden decrease in optical performance (MTF).

[0030] A camera module according to an embodiment of the present invention may set the linear expansion coefficient of the barrel to minimize decentering of the lens depending on the lens material and diameter. Specifically, the linear expansion coefficient, which is an inherent property of a material, differs depending on the lens material. In this case, when the camera module changes from a high temperature state to a low temperature state, decentering of the lens may occur due to differences in the amount of expansion and contraction caused by differences in the linear expansion coefficients of the lenses included in the camera module and between the lens and the barrel. Therefore, differences in the amount of expansion and contraction between the lens and the barrel may be controlled by taking into account the range of the linear expansion coefficient of each lens depending on the lens material and the lens diameter. That is, a camera module according to an embodiment of the present invention may set the range of the linear expansion coefficient of the barrel to a range in which decentering occurring in high temperature and low temperature states does not significantly affect the optical characteristics of the camera module. Therefore, by setting the camera module to have a linear expansion coefficient of the barrel within a set range for a set linear expansion coefficient of the lens and a set diameter, the decentering of the lens can be adjusted to a decentering range in which the optical characteristics of the camera module are not significantly affected in high temperature and low temperature states.

[0031] Therefore, the camera module according to the embodiment can maintain uniform operational performance at room temperature, high temperature, and low temperature by minimizing the decentering range even in high temperature and low temperature conditions. According to the embodiment of the invention, the optical reliability of the camera module can be improved. Furthermore, the reliability of the camera module and the vehicle camera device including the camera module can be improved. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is an example of a cross-sectional side view of a camera module according to a first embodiment of the invention. [Figure 2] 2 is a partial cross-sectional side view showing the coupling of two lenses closer to the object side and a lens barrel in the camera module of FIG. 1. FIG. [Figure 3] 2 is a partial cross-sectional side view showing the connection between the last lens and the lens barrel closest to the sensor in the camera module of FIG. 1. FIG. [Figure 4] 1 is a perspective view showing a lens barrel according to a first embodiment of the invention. [Figure 5] 5 is an example of a cross-sectional side view of the lens barrel of FIG. 4. [Figure 6] 5 is a side cross-sectional view of a camera module having the lens barrel of FIG. 4 of the invention. [Figure 7] 7 is a partial side cross-sectional view illustrating first and second support portions of the lens barrel of FIG. 6. FIG. [Figure 8] 7 is a partial enlarged view for explaining a third support portion of the lens barrel of FIG. 6. FIG. [Figure 9] 7 is a diagram illustrating the outer diameter of the lens barrel of FIG. 6. [Figure 10] 1A and 1B are diagrams comparing the thermal stress of the comparative example and the camera module of the present invention. [Figure 11] 10A and 10B are diagrams comparing the thermal deformation rates of the camera modules of the comparative example and the invention. [Figure 12] Graphs (A) and (B) compare the diffraction optical performance change rate (MTF) of the comparative example and the camera module of the present invention. [Figure 13] FIG. 10 is a side cross-sectional view illustrating a camera module according to a second embodiment of the present invention. [Figure 14] FIG. 10 is a side cross-sectional view illustrating a camera module according to a second embodiment of the present invention. [Figure 15] 10 is a table for explaining the decentering of a lens portion of a camera module according to a second embodiment of the invention. [Figure 16]10 is a table for explaining the decentering of a lens portion of a camera module according to a second embodiment of the invention. [Figure 17] 10 is a table for explaining the decentering of a lens portion of a camera module according to a second embodiment of the invention. [Figure 18] 10 is a table for comparing the diameter change of the lens in the lens barrel in the camera module according to the third embodiment of the invention. [Figure 19] 10 is a table for comparing the diameter change of the lens in the lens barrel in the camera module according to the third embodiment of the invention. [Figure 20] 1 is a plan view showing an example of a vehicle having a camera module according to an embodiment of the invention; DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The technical concept of the present invention is not limited to some of the described embodiments, but may be embodied in various forms, and one or more components between the embodiments may be selectively combined or substituted within the scope of the technical concept of the present invention. Furthermore, terms (including technical and scientific terms) used in the embodiments of the present invention should be interpreted as meanings that are commonly understood by those skilled in the art to which the present invention pertains, unless otherwise expressly specified. Commonly used terms, such as dictionary-defined terms, should be interpreted in light of the context of the relevant technology.

[0034] The terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention. In this specification, the singular can include the plural unless otherwise specified. For example, "A and (and) at least one (or more) of B and C" refers to one or more of all possible combinations of A, B, and C. Furthermore, when describing components of the embodiments of the present invention, terms such as "first," "second," A, B, (A), and (B) can be used. These terms are used to distinguish the component from other components and do not limit the nature or order of the components. Furthermore, when a component is described as being "coupled," "bonded," or "connected" to another component, it can refer not only to a case where the component is directly coupled or connected to the other component, but also to a case where the component is "coupled," "bonded," or "connected" to the other component via an additional component between the component and the other component. Furthermore, when a component is described as being formed or disposed "above or below" another component, "above or below" refers not only to a case where the two components are in direct contact with each other, but also to a case where one or more additional components are formed or disposed between the two components. Furthermore, when the term "above or below" is used, it can mean not only an upper direction but also a lower direction based on one component. Furthermore, the various embodiments described below can be combined with each other unless otherwise specified. Furthermore, for any missing part in the description of one embodiment of the various embodiments, the description of another embodiment can be applied unless otherwise specified.

[0035] In the description of the invention, the first lens refers to the lens closest to the object side, and the last lens refers to the lens closest to the image side (or sensor surface). The last lens may include a lens adjacent to the image sensor. Unless otherwise specified in the description of the invention, all units for lens radius, thickness / distance, TTL, etc. are in millimeters. In this specification, the shape of a lens is expressed relative to the optical axis of the lens. For example, when the object-side surface of a lens is described as being convex or concave, it means that the object-side surface of the lens is convex or concave near the optical axis, not that the periphery of the optical axis is convex or concave. Therefore, even if the object-side surface of a lens is described as being convex, the portion of the object-side surface of the lens near the optical axis may have a concave shape, or the opposite shape. It should be noted that the thickness and radius of curvature of a lens are measured relative to the optical axis of the lens. That is, a convex lens surface means that the lens surface in the area corresponding to the optical axis has a convex shape, and a concave lens surface means that the lens surface in the area corresponding to the optical axis has a concave shape. Furthermore, the "object-side surface" means the lens surface facing the object side relative to the optical axis, and the "sensor-side surface" means the lens surface facing the sensor side relative to the optical axis.

[0036] FIG. 1 is an example of a side cross-sectional view of a camera module according to a first embodiment of the invention, FIG. 2 is a partial side cross-sectional view showing the coupling of the two lenses closest to the object side and the lens barrel in the camera module of FIG. 1, and FIG. 3 is a partial side cross-sectional view showing the coupling of the last lens closest to the sensor side and the lens barrel in the camera module of FIG. 1.

[0037] 1 to 3, a camera module 1000 according to a first embodiment of the present invention may include a lens barrel 500, a lens unit 100 having a plurality of lenses 111, 113, and 115, spacing maintaining members 121, 123, 124, and 125 having a light-blocking function, a main board 190, and an image sensor 192. The camera module 1000 may include an optical cover glass 194 and an optical filter 196 between the last lens of the lens unit 100 and the image sensor 192.

[0038] The lens barrel 500 may include a through hole 515 having a first opening 101 that is open at the top and a second opening 102 that is open at the bottom. The first opening 101 and the second opening 102 may correspond to the optical axis direction. The through hole 515 may open the interior of the lens barrel 500 in the optical axis Lz direction and may function as a storage portion in which the lenses 111, 113, and 115 are stored. The through hole 515 may have different upper, lower, and middle widths.

[0039] The lens unit 100 inside the lens barrel 500 is exposed through the first opening 101. More specifically, the lens disposed at the top of the lenses of the lens unit 100 is exposed through the first opening 101. As a result, the external light can be incident on the lens unit 100 inside the lens barrel 500. The image sensor 192 is exposed through the second opening 102. More specifically, the lens disposed at the bottom of the lenses of the lens unit 100 is exposed through the second opening 102. That is, the lens disposed at the bottom is disposed to face the image sensor 192 through the second opening 102. As a result, light that has sequentially passed through the plurality of lenses can be incident on the image sensor 192 outside the lens barrel 500.

[0040] The lens unit 100 may be an optical system in which three or more lenses 111, 113, and 115 are stacked. The lens unit 100 may include an optical system in which five or fewer lenses are stacked. The lens unit 100 may include three or more solid lenses. The lens unit 100 may include at least one plastic lens, or at least one glass lens and one plastic lens. The lens unit 100 according to an embodiment of the invention may have more plastic lenses than glass lenses, or two or more plastic lenses. Here, the lens unit 100 may be stacked with plastic lenses and / or glass lenses. Here, the coefficient of thermal expansion (CTE) of the plastic material may be five or more times higher than that of the glass material, and the change in refractive index as a function of temperature (|dN / dt|) of the plastic material may be ten or more times higher than that of the glass material. Here, dN represents the change in refractive index of the lens, and dT represents the change in temperature.

[0041] For ease of explanation, the lens unit 100 includes a first lens 111, a second lens 113, and a third lens 115, which are stacked from the object side toward the image sensor 192 and aligned along the optical axis Lz.

[0042] The lenses 111, 113, and 115 of the lens unit 100 are coupled to through-holes 515 in the lens barrel 500, for example, from the sensor side toward the object side, or in the opposite direction, or in both directions. In the following description, the lenses 111, 113, and 115 in the through-holes 515 of the lens barrel 500 are coupled to the sensor side toward the object side.

[0043] Each of the lenses 111, 113, and 115 may include an effective area having an effective diameter through which light is incident, and a non-effective area outside the effective area. Flange portions 111A, 113A, and 115A of the lenses 111, 113, and 115 may be the non-effective areas. The non-effective areas may be areas where light is blocked by light-shielding films 121 and 124. The flange portions 111A, 113A, and 115A extend from the effective areas of the lenses 111, 113, and 115 in a direction perpendicular to the optical axis Lz, or in a radial or circumferential direction.

[0044] A first light-blocking film 121 is disposed on the outer periphery between the first lens 111 and the second lens 113, and at least one of a spacing member 123 and a second light-blocking film 124 is disposed on the outer periphery between the second lens 113 and the third lens 115. The first and second light-blocking films 121 and 124 may function as a member for blocking light from non-effective areas, and one of the first and second light-blocking films 121 and 124 may be used as an aperture. The spacing member 123 may maintain the distance between the second and third lenses 113 and 115 and may have a light-blocking function. If the spacing member 123 is not present, flanges of two lenses aligned in the optical axis direction may contact each other or may be contacted by a light-blocking film. At least one or both of the first light-blocking film 121, the spacing member 123, and the second light-blocking film 124 may function as a spacer. The thickness of the first and second light-shielding films 121 and 124 may be thinner than the thickness of the gap maintaining portion 123. Here, a stop may be disposed around the second surface S2 of the first lens 111 or may be used as the second surface S2.

[0045] A support member 125 is disposed around the lower periphery of the third lens 115, and the support member 125 can support the third lens 115 or maintain a distance from the optical filter 196. Here, a portion of the outer surface S30 of the third lens 115 is adhered to the inner wall 511 of the lens barrel 500 with an adhesive.

[0046] The diameter A1 of the first lens 111 may be smaller than the diameter A2 of the second lens 113, and the diameter A2 of the second lens 113 may be smaller than the diameter A3 of the third lens 115. The diameters A1, A2, and A3 of the first, second, and third lenses 111, 113, and 115 may gradually increase from the object side toward the sensor side. The stacked outer shape of the first, second, and third lenses 111, 113, and 115 may have a pyramidal or polygonal shape. The diameters A1, A2, and A3 of the lenses 111, 113, and 115 may be the diameters of an area having an active area and an inactive area. The diameters A1, A2, and A3 of the lenses 111, 113, and 115 may be the diameters of the flange portions 111A, 113A, and 115A, respectively.

[0047] The first lens 111 is the lens closest to the subject, and at least one or both of the first object-side surface S1 into which light enters and the second sensor-side surface S2 from which light exits may be spherical or aspherical. The first surface S1 of the first lens 111 may have a convex shape, and the second sensor-side surface S2 may have a concave shape. The first lens 111 may be made of glass. The first lens 111 may include a first flange portion 111A on its outer side. A portion of the outer surface S10 of the first flange portion 111A may contact the inner wall 511 of the lens barrel 500. The length of the outer surface of the first flange portion 111A that contacts the inner wall 511 of the lens barrel 500 may be 70% or more of the thickness of the first flange portion 111A. The length direction of the contact surface of the first flange portion 111A is parallel to the optical axis Lz or inclined at a predetermined angle, or the first flange portion 111A extends from the outside of the effective diameter of the first lens 111 in a direction X perpendicular to the optical axis Lz. The thickness of the first flange portion 111A may be the distance between two surfaces of the object side and sensor side regions of the first flange portion 111A that contact the optical element. The optical element may be an object disposed inside the lens barrel, such as a lens, a lens barrel, a spacing member, an aperture, or a light-shielding film. The length of the contact surface of the lens barrel 500 with the inner wall 511 is the length from one end of the outer surface of the first flange portion 111A on the object side to the other end on the sensor side.

[0048] Since the first lens 111 is made of a glass material, discoloration caused by plastic materials can be prevented and deformation F1 due to heat can be reduced when the camera module 1000 is exposed to light inside or outside a vehicle. When the camera module 1000 is installed inside a vehicle, the first lens 111 may be made of a glass material or a plastic material.

[0049] The first lens 111 may have a refractive index of 1.7 or more, 1.8 or more, or in the range of 1.7 to 2.3. When expressed as an absolute value, the radius of curvature of the first surface S1 of the first lens 111 at the optical axis Lz may be smaller than the radius of curvature of the second surface S2, for example, 3.3 mm or less. The difference between the radius of curvature of the first surface S1 and the second surface S2 of the first lens 111 may be 1 mm or more, for example, in the range of 1 mm to 3 mm. The center thickness of the first lens 111 may be the thickest among the lenses of the lens unit 100, for example, 1 mm or more. Regarding the effective diameter of the first lens 111, the effective diameter of the first surface S1 may be larger than the effective diameter of the second surface S2.

[0050] The second lens 113 and the third lens 115 may be made of a material different from that of the first lens 111 and may have a refractive index different from that of the first lens 111. The second lens 113 may be made of a plastic material. The second lens 113 may be disposed between the first lens 111 and the third lens 115 and may have a second flange portion 113A on the outer side. The third lens 115 may be made of a plastic material. The third lens 115 may be disposed between the second lens 113 and the optical filter 196 and may have a third flange portion 115A on the outer side. The second lens 113 and the third lens 115 may be injection molded from a plastic material.

[0051] 1 and 2, the second lens 113 includes a third object-side surface S3 and a fourth sensor-side surface S4, and the third surface S3 and the fourth surface S4 may be aspherical. The third surface S3 and the fourth surface S4 of the third lens 113 may have different radii of curvature. The third surface S3 may have a concave shape, and the sensor-side fourth surface S4 may have a convex shape. As another example, the second lens 113 has two surfaces with different radii of curvature, for example, the third surface S3 may have a convex shape and the fourth surface S4 may have a concave shape. Alternatively, the third surface S3 may have a convex shape and the fourth surface S4 may have a convex shape. Alternatively, the third surface S3 may have a concave shape and the fourth surface S4 may have a concave shape.

[0052] The second lens 113 may include a second flange portion 113A on its outer periphery. A portion of the outer surface S20 of the second flange portion 113A may contact the inner wall 511 of the lens barrel 500. The second flange portion 113A extends from outside the effective diameter of the second lens 113 in a direction X perpendicular to the optical axis Lz. The thickness D1 of the second flange portion 113A may be the distance between two surfaces of the object side and sensor side regions of the second flange portion 113A that contact an optical element. The optical element may be an object disposed inside the lens barrel, such as a lens, a lens barrel, a spacing member, an aperture, or a light-shielding film. The thickness D1 of the second flange portion 113A of the second lens 113 may be the distance between the surface of the second flange portion 113A that contacts the first light-shielding film 121 and the surface that contacts the spacing member 123, for example, the distance may be the distance in a direction parallel to the optical axis.

[0053] 2, the outer side S20 of the second flange portion 113A may include a first contact surface S21 that contacts the inner side wall 511 of the lens barrel 500, a first inclined surface S23 between the first contact surface S21 and the object side surface, and a second inclined surface S24 between the first contact surface S21 and the sensor side surface. The outer side S20 of the second flange portion 113A may include a first non-contact surface S22 that extends from the first contact surface S21 in an axial direction parallel to the optical axis Lz and is disposed between the first contact surface S21 and the second inclined surface S24.

[0054] The first contact surface S21 of the second flange portion 113A is disposed on the outermost side of the second flange portion 113A and may be in contact with the inner wall 511 of the lens barrel 500. The first non-contact surface S22 may extend vertically or coplanarly from a lower end of the first contact surface S21 and may be in non-contact with the inner wall 511 of the lens barrel 500. A contact length D2 of the first contact surface S21 may be smaller than a thickness D1 of the second flange portion 113A. The contact length D2 of the first contact surface S21 may be 50% or less of the thickness D1 or may be in a range of 20% to 50%. A direction Lz1 of the contact length D2 may be in the direction of an axis Lz1 parallel to the optical axis Lz or may be inclined at a predetermined angle with respect to the axis Lz1 parallel to the optical axis Lz. The distance between the first non-contact surface S22 and the inner wall 511 may increase as it approaches the sensor. A vertical length D5 of the first non-contact surface S22 may be smaller than a contact length D2 of the first contact surface S21. The length D3 of the first non-contact surface S22 extends further from the lower end of the first contact surface S21 toward the sensor when the second lens 113 is injection molded to be spaced apart from the inner wall 511 of the lens barrel 500. This distance allows the first contact surface S21 and the inner wall 511 of the lens barrel 500 to closely contact each other without interfering with the surface contact of the first contact surface S21 even if structures such as burrs are generated on the first non-contact surface S22. Alternatively, the first non-contact surface S22 may prevent assembly defects of the second lens 113 due to burrs. The length D5 of the first non-contact surface S22 is formed to be 1 / 15 or 1 / 20 of the thickness D1 of the second flange portion 113A. The thickness D1 of the second flange portion 113A may be 0.7 mm or more, for example, in the range of 0.7 mm to 1.2 mm.

[0055] The first inclined surface S23 extends from an object-side end of the first contact surface S21 toward the object side surface of the first flange portion 113A at a first angle R1. The first angle R1 may be 40 degrees or less, for example, in the range of 10 degrees to 40 degrees or 15 degrees to 35 degrees, with respect to an axis Lz1 parallel to the optical axis. If the first angle R1 is smaller than this range, injection molding may be difficult, and if it is larger than this range, problems such as a reduction in the fixing force of the second flange portion 113A of the second lens 113 or distortion may occur.

[0056] The second inclined surface S24 extends from the sensor-side end of the first non-contact surface S22 toward the sensor side of the first flange portion 113A at a second angle R2. The second angle R2 may be 40 degrees or less, for example, in the range of 10 to 40 degrees or 15 to 35 degrees, with respect to an axis Lz1 parallel to the optical axis. The second angle R2 may be equal to or smaller than the first angle R1. If the second angle R2 is smaller than this range, it may be difficult to perform injection molding. If the second angle R2 is larger than this range, it may cause problems such as a reduction in the fixing strength of the second flange portion 113A of the second lens 113 or distortion.

[0057] The refractive index of the second lens 113 may be lower than that of the first lens 111, and may be less than 1.7, for example, in the range of 1.45 to 1.69. The difference in refractive index between the second lens 113 and the first lens 111 may be 0.3 or more. When expressed as an absolute value, the radius of curvature of the concave third surface S3 of the second lens 113 may be larger than the radius of curvature of the convex fourth surface S4, and may be, for example, 7 mm or more or in the range of 5.1 mm to 7 mm. The radius of curvature of the fourth surface S4 may be, in absolute value, 5 mm or less, for example, in the range of 2 mm to 5 mm. The difference between the radius of curvature of the third surface S3 and the fourth surface S4 of the second lens 113 may be 1 mm or more, for example, in the range of 1 mm to 5 mm. The center thickness of the second lens 113 may be the second thickest among the lenses in the lens unit 100, for example, it may be thinner than the center thickness of the first lens 111 but thicker than the center thickness of the third lens 113. The center distance between the second lens 113 and the first lens 111 may be smaller than the thickness of the first lens 111 and may be larger than the center distance between the second and third lenses 113 and 115. Regarding the effective diameter of the second lens 113, the effective diameter of the third surface S3 may be smaller than the effective diameter of the fourth surface S4. The effective diameter of the third surface S4 may be larger than the effective diameter of the second surface S2 and smaller than the effective diameter of the first surface S1.

[0058] Since the second lens 113 is made of plastic, which has a higher thermal expansion coefficient than glass, thermal deformation F2 occurs to a greater extent. In an embodiment of the invention, when there is a difference in the radii of curvature between the third and fourth surfaces S3 and S4 of the second lens 113, a mitigation structure may be provided on the outer surface S20 of the second flange portion 113A to minimize thermal deformation F2 due to the difference in radii of curvature between the two surfaces S3 and S4 and the plastic material. The mitigation structure may optimize the area or vertical length of the first contact surface S21 on the outer surface S20 of the second flange portion 113A based on the thermal deformation F2 due to the difference in radii of curvature between the third and fourth surfaces S3 and S4 on the optical axis of the second lens 113.

[0059] When the radius of curvature of the third surface S3 of the second lens 113 is greater than the radius of curvature of the fourth surface S4 by 1 or more in absolute value on the optical axis Lz, the optical axis center P1 between the third surface S3 and the fourth surface S4 may be located closer to the sensor side than the vertical center P3 of the second flange portion 113A. Also, the center P2 of the length D2 of the first contact surface S21 may be located closer to the object side than the optical axis center P1 of the second lens 113, and closer to the object side than the vertical center P3 of the second flange portion 113A.

[0060] Because the center P2 of the first contact surface S21 is located closer to the object side than the vertical center P3 of the second flange portion 113A, the first contact surface S21 contacts the inner wall 511 of the lens barrel 500 more at the upper outer surface of the second flange portion 113A than at the lower outer surface, thereby mitigating thermal deformation F2 due to the difference in the radii of curvature between the third and fourth surfaces S3 and S4 of the second lens 113 and the plastic material. For example, the upper portion may refer to the object side, and the lower portion may refer to the sensor side. For example, the smaller the radii of curvature, the greater the change in optical performance due to temperature changes, and the more sensitive the lens is to temperature changes. When the difference in radii of curvature is 1 or more, the lens with the smaller radii of curvature is more sensitive to temperature changes and the greater the change in optical performance due to temperature changes. By positioning the center P2 of the first contact surface S21 farther from the surface with the smaller radii of curvature, degradation of optical performance due to temperature changes can be mitigated. Here, the length D2 of the first contact surface S21 is formed within a range of 20% to 50% of the thickness D1 of the second flange portion 113A. The first contact surface S21 makes surface contact with the inner wall 511 of the lens barrel 500 at the outer upper portion of the second flange portion 113A, thereby mitigating thermal deformation F2 transmitted to the outer lower portion of the second flange portion 113A. If the length D2 of the first contact surface S21 is smaller than this range, the position of the second lens 113 may be deformed due to temperature changes. If the length D2 of the first contact surface S21 is larger than this range, the mitigation of the thermal deformation F2 of the second lens 113 may be minimal, making injection molding difficult and increasing thermal stress on the optical axis Lz, which may increase the thermal deformation rate. The vertical length (D2 + D5) of the outer side S20 of the second flange portion 113A is formed within a range of 20% to 50% of the thickness D1 of the second flange portion 113A.

[0061] The vertical length (D2+D5) of the outer side S20 of the second flange portion 113A may be greater than the length D4 between two horizontal straight lines passing through both ends of the first inclined surface S23 of the second flange portion 113A, and may be smaller than the length D3 between two horizontal straight lines passing through both ends of the second inclined surface S24 of the second flange portion 113A.

[0062] 1 and 3, the third lens 115 is made of plastic and includes a fifth object-side surface S5 and a sixth sensor-side surface S6, which may be aspherical. The fifth surface S5 may be convex on the optical axis Lz, and the sixth surface S6 may be concave on the optical axis Lz. As another example, the third lens 115 may include two surfaces with different radii of curvature, expressed in absolute values, such as a structure in which the fifth surface S5 is convex and the sixth surface S6 is concave, a structure in which the fifth surface S5 is convex and the sixth surface S6 is convex, or a structure in which the fifth surface S5 is concave and the sixth surface S6 is concave. The third lens 115 may include a third flange portion 115A on its outer side. A portion of the outer surface S30 of the third flange portion 115A may contact the inner wall 511 of the lens barrel 500.

[0063] The third flange portion 115A extends from the outside of the effective diameter of the third lens 115 in a direction X perpendicular to the optical axis Lz, and its thickness T1 may be the distance between two surfaces of the object-side and sensor-side regions of the third flange portion 115A that contact an optical element. The optical element may be an object disposed inside the lens barrel, such as a lens, a lens barrel, a spacing member, an aperture, or a light-shielding film. The thickness T1 of the third flange portion 115A of the third lens 115 may be the distance between the surface of the third flange portion 115A that contacts the second light-shielding film 124 and the surface that contacts the support member 125, for example, the distance may be the distance in a direction parallel to the optical axis.

[0064] 3 , the outer side S30 of the third flange portion 115A may include a second contact surface S31 that contacts an inner side wall 511 of the lens barrel 500, a third inclined surface S33 between the second contact surface S31 and the object side, and a fourth inclined surface S34 between the first contact surface S31 and the sensor side. The outer side S30 of the third flange portion 115A may include a second non-contact surface S32 that extends from the second contact surface S31 in an axial direction parallel to the optical axis Lz and is disposed between the second contact surface S31 and the fourth inclined surface S34. The second contact surface S31 is disposed at the outermost side of the third flange portion 115A and may contact the inner side wall 511 of the lens barrel 500. The second non-contact surface S32 may extend vertically or coplanarly from a lower end of the second contact surface S31 and may not contact the inner side wall 511 of the lens barrel 500. The contact length T2 of the second contact surface S31 may be smaller than the thickness T1 of the third flange portion 115A. The contact length T2 of the second contact surface S31 may be 60% or less of the thickness T1, or may be in a range of 30% to 60%, or may be in a range of 20% to 50%. The direction Lz2 of the contact length T2 may be an axial direction parallel to the optical axis Lz, or may be inclined at a predetermined angle with respect to the axis Lz2 parallel to the optical axis Lz. The distance between the second non-contact surface S32 and the inner wall 511 may increase as it approaches the sensor side. The vertical length T5 of the second non-contact surface S32 may be smaller than the contact length T2 of the second contact surface S31. The length T3 of the second non-contact surface S32 extends further from the lower end of the second contact surface S31 toward the sensor when the third lens 115 is injection molded to be spaced apart from the inner wall 511 of the lens barrel 500. This distance allows the second contact surface S31 and the inner wall 511 of the lens barrel 500 to be in close contact with each other without interfering with the surface contact of the second contact surface S31 even if structures such as burrs are generated on the second non-contact surface S32. Alternatively, the second non-contact surface S32 can prevent assembly defects of the third lens 115 due to burrs. The length T5 of the second non-contact surface S32 is formed to be 1 / 15 or 1 / 20 of the thickness T1 of the third flange portion 115A.The thickness T1 of the third flange portion 115A is smaller than the thickness D1 and may be 0.6 mm or more, for example, in the range of 0.6 mm to 1 mm.

[0065] The third inclined surface S33 extends from an object-side end of the second contact surface S31 toward the object side of the second flange portion 115A at a third angle R3. The third angle R3 may be 40 degrees or less, for example, in the range of 10 to 40 degrees or 15 to 35 degrees, with respect to an axis Lz2 parallel to the optical axis. If the third angle R3 is smaller than this range, it may be difficult to perform injection molding. If it is larger than this range, the fixing force of the third flange portion 115A of the third lens 115 may be reduced or problems may occur with twisting.

[0066] The fourth inclined surface S34 extends from the sensor-side end of the second non-contact surface S32 toward the sensor side of the third flange portion 115A at a fourth angle R4. The fourth angle R4 may be 40 degrees or less, for example, in the range of 10 to 40 degrees or 15 to 35 degrees, with respect to an axis Lz2 parallel to the optical axis. The fourth angle R4 may be equal to or greater than the third angle R3. If the fourth angle R4 is smaller than this range, it may be difficult to perform injection molding, and if it is larger than this range, it may cause problems such as a reduction in the fixing strength of the third flange portion 115A of the third lens 115 or distortion.

[0067] The refractive index of the third lens 115 may be lower than that of the first lens 111, and may be less than 1.7, for example, in the range of 1.45 to 1.69. The second and third lenses 113 and 115 may be made of the same material and have the same refractive index. The difference in refractive index between the third lens 115 and the first lens 111 may be 0.3 or more. In terms of absolute values, the radius of curvature of the convex fifth surface S5 of the third lens 115 may be larger than the radius of curvature of the concave sixth surface S6, and may be, for example, 3 mm or more or in the range of 3 mm to 6.5 mm. The radius of curvature of the sixth surface S6 may be, in absolute value, 4 mm or less, for example, in the range of 1.5 mm to 4 mm. The difference between the radius of curvature of the fifth surface S5 of the third lens 115 and the radius of curvature of the sixth surface S6 may be 1 mm or more, for example, in the range of 1 mm to 5 mm or 2 mm to 5 mm.

[0068] The central thickness of the third lens 115 may be thinner than the central thickness of the first lens 111 and thinner than the central thickness of the second lens 113. The center distance between the third lens 115 and the second lens 113 may be larger than the center distance between the first and second lenses 111 and 113. The center distance between the third lens 115 and the optical filter 196 may be smaller than the center distance between the second and third lenses 113 and 115. Regarding the effective diameter of the third lens 115, the effective diameter of the fifth surface S5 may be smaller than the effective diameter of the sixth surface S6. The effective diameter of the sixth surface S6 may be larger than the effective diameter of the third surface S3 and may be larger than the effective diameter of the first surface S1.

[0069] The third lens 115 is made of plastic, which has a higher thermal expansion coefficient than glass, resulting in greater thermal deformation F3. In an embodiment of the invention, when there is a difference in the radii of curvature between the fifth and sixth surfaces S5 and S6 of the third lens 115, a mitigation structure may be provided on the outer surface S30 of the third flange portion 115A to minimize the thermal deformation F3 caused by the difference in radii of curvature between the two surfaces S5 and S6 and the plastic material. The mitigation structure may optimize the area or vertical length of the second contact surface S31 on the outer surface S30 of the third flange portion 115A based on the thermal deformation F3 caused by the difference in radii of curvature between the fifth and sixth surfaces S5 and S6 on the optical axis of the third lens 115. When the radius of curvature of the fifth surface S5 of the third lens 115 is greater than the radius of curvature of the sixth surface S6 by 1 or more in absolute value on the optical axis Lz, the optical axis center P5 between the fifth surface S5 and the sixth surface S4 may be located closer to the sensor side than the vertical center P6 of the third flange portion 115A. Furthermore, the center P6 of the length T2 of the second contact surface S31 may be located closer to the object side than the optical axis center P5 of the third lens 115 and closer to the object side than the vertical center P7 of the third flange portion 115A. Since the center P6 of the second contact surface S31 is located closer to the object side than the vertical center P7 of the third flange portion 115A, the second contact surface S31 makes more contact with the inner wall 511 of the lens barrel 500 at the upper outer side of the third flange portion 115A than at the lower outer side, thereby mitigating the difference in the radii of curvature of the fifth and sixth surfaces S5 and S6 of the third lens 115 and thermal deformation F3 due to the plastic material. For example, the upper portion may refer to the object side, and the lower portion may refer to the sensor side. For example, the smaller the radius of curvature, the greater the change in optical performance due to temperature changes in the lens. When the difference in the radii of curvature is 1 or more, the lens with the smaller radius of curvature is more sensitive to temperature changes and is therefore a lens with a greater change in optical performance due to temperature changes. By positioning the center P6 of the second contact surface S31 away from the surface with the smaller radius of curvature, it is possible to mitigate the degradation of optical performance due to temperature changes.

[0070] Here, the length T2 of the second contact surface S31 is set to 60% or less of the thickness T1 of the third flange portion 115A, and is set to a range of 20% to 50% or 30% to 60%. The second contact surface S31 makes surface contact with the inner wall 511 of the lens barrel 500 at the outer upper portion of the third flange portion 115A, thereby mitigating thermal deformation F3 transmitted to the outer upper portion of the third flange portion 115A. If the length T2 of the second contact surface S31 is smaller than this range, the mitigation of thermal deformation F3 of the third lens 115 is minimal. If the length T2 is larger than this range, injection molding becomes difficult, thermal stress on the optical axis Lz increases, and the thermal deformation rate increases. The vertical length (T2 + T5) of the outer side S30 of the third flange portion 115A is set to 60% or less of the thickness T1 of the third flange portion 115A, and is set to a range of 20% to 50% or 30% to 60%.

[0071] The vertical length (T2+T5) of the outer side S30 of the third flange portion 115A may be greater than the length T4 between two horizontal lines passing through both ends of the third inclined surface S33 of the third flange portion 113A and may be less than the length T3 between two horizontal lines passing through both ends of the fourth inclined surface S34 of the third flange portion 113A. As another example, in the second and third lenses 11, 3115, when the absolute value of the difference in the radii of curvature of the third and fourth surfaces S3, S4 or the difference in the radii of curvature of the fifth and sixth surfaces S5, S6 is less than 1 on the optical axis Lz, the centers P2, P6 of the first and second contact surfaces S21, S31 are positioned closer to the centers P3, P7 of the flange portions 111A, 113A, 115A.

[0072] Table 1 shows the lens data of the first lens 111 to the third lens 115 according to the embodiment of the invention.

[0073] [Table 1]

[0074] In Table 1, the seventh surface may be the object side surface of an optical filter, the eighth surface may be the sensor side surface, the ninth surface may be the object side surface of a cover glass, and the tenth surface may be the sensor side surface. In the first embodiment of the invention, the lens barrel 500 may be made of a heat dissipating material or a metal material to reduce thermal deformation of the second and third lenses 113 and 115. The lens barrel 500 may have a top view shape of a cylinder or a polygonal prism. The lens barrel 500 may be made of resin, plastic, or metal. The surface of the lens barrel 500 may be coated or painted with a hydrophilic material.

[0075] The first and second light-shielding films 121 and 124, the gap maintaining part 123, or the support member 125 may have an opening therein and may be attached to the flange parts 111A, 113A, and 115A and the inner wall 511 of the lens barrel 500 with an adhesive. The first and second light-shielding films 121 and 124, the gap maintaining part 123, and the support member 125 may include a PE film (Poly Ethylene film) or a polyester (PET) film. As another example, the first and second light-shielding films 121 and 124, the gap maintaining part 123, or the support member 125 may be made of a metal or an alloy with an oxide film formed on its surface. The material contained in the metal or alloy may include at least one of In, Ga, Zn, Sn, Al, Ca, Sr, Ba, W, U, Ni, Cu, Hg, Pb, Bi, Si, Ta, H, Fe, Co, Cr, Mn, Be, B, Mg, Nb, Mo, Cd, Sn, Zr, Sc, Ti, V, Eu, Gd, Er, Lu, Yb, Ru, Y, and La. The oxide film may be an oxide material treated to be a black oxide or a brown oxide using copper.

[0076] The image sensor 192 is disposed on the main board 190. The main board 190 may have the image sensor 192 attached, seated, contacted, fixed, temporarily fixed, supported, or coupled to it in a plane intersecting the optical axis Lz. Alternatively, according to another embodiment, a groove or hole (not shown) capable of accommodating the image sensor 192 may be formed in the main board 190, and the embodiment is not limited to a specific form in which the image sensor 192 is disposed on the main board 180. The main board 190 may be a rigid PCB or an FPCB.

[0077] The image sensor 192 may convert light passing through the lens unit 100 into image data. A sensor holder is disposed at the bottom of the housing 500 to surround the image sensor 192 and protect the image sensor 192 from external foreign objects or impacts. The image sensor 192 may be any one of a CCD (Charge Coupled Device), a CMOS (Complementary Metal-Oxide Semiconductor), a CPD, or a CID. When there are multiple image sensors 192, one of them may be a color (RGB) sensor and the other may be a monochrome sensor.

[0078] The optical filter 196 is disposed between the lens unit 100 and the image sensor 192. The optical filter 196 can filter light corresponding to a specific wavelength range from light passing through the lenses 111, 113, 115, and 117. The optical filter 196 may be an infrared (IR) blocking filter that blocks infrared light or an ultraviolet (UV) blocking filter that blocks ultraviolet light, but embodiments are not limited thereto. The optical filter 196 is disposed on the image sensor 192. A cover glass 194 is disposed between the optical filter 196 and the image sensor 192 to protect the upper part of the image sensor 192 and prevent a decrease in reliability of the image sensor 192.

[0079] The camera module 1000 according to an embodiment of the invention may include a driving member (not shown), which may move or tilt a barrel having at least one of the lenses in the optical axis direction and / or in a direction perpendicular to the optical axis direction. The camera module may include an AF (Auto Focus) function and / or an OIS (Optical Image Stabilizer) function. The camera module 1000 according to an embodiment of the invention may be applied to an infrared camera or a driver monitoring camera. The camera module 1000 may have a field angle of 50 degrees or more, for example, in the range of 50 degrees to 70 degrees. Here, when the lens unit 100 is formed by stacking a plastic lens and at least one glass lens together, thermal deformation due to the plastic lens may be minimized. For example, by arranging the lengths D2 and T2 of the first and second contact surfaces S21 and S31 of the second and third lenses 113 and 115 to be compensated for according to the thermal deformations F2 and F3, the MTF change rate of the diffraction optical performance at a high temperature (e.g., 80 to 90 degrees) compared to a normal temperature (e.g., 20 to 30 degrees) can be 10% or less. The high temperature can include the temperature inside a vehicle.

[0080] 4 and 5, the lens barrel 500 may include an upper barrel portion 550 and a lower barrel portion 510. The upper barrel portion 550 and the lower barrel portion 510 may be integrally formed. The upper barrel portion 550 has an open area 551 therein that is larger in diameter than the opening 101. The open area 551 is open at the top, and a plurality of ribs 555 extend from the center of the optical axis toward the outer periphery. Three or more of the ribs 555 may be spaced apart from one another to support the upper barrel portion 550. The upper barrel portion 550 is connected to another transport device, and the ribs 555 prevent a decrease in rigidity. One surface of the upper barrel portion 550 has a flat surface 559 that is used as a fixed position or a bottom surface. The upper barrel portion 550 has a floor 553 and a sidewall 554, and the ribs 555 are connected to the floor 553 and the sidewall 554. The lower barrel portion 510 extends along the outer circumferential surface of the opening 101 via the floor portion 553. The lower barrel portions 510 of the lens barrel 550 are provided with structures or shapes having different outer diameters, so that even if thermal deformation occurs due to the lenses 111, 113, and 115 inside, it can be effectively suppressed.

[0081] 6, the lower barrel portion 510 may include a first support portion 501 extending perpendicularly to the outer side of the first lens 111, a second support portion 503 extending perpendicularly to the outer side of the second lens 113, and a third support portion 505 extending perpendicularly to the outer side of the third lens 115. The first, second, and third support portions 501, 503, and 505 may include sections where an inner wall 511 and an outer surface 513 of the lower barrel portion 510 are parallel to each other outside the first, second, and third lenses 111, 113, and 115. The first support portion 501 may include a first inclined portion 502 extending inclined toward the second support portion 503, and a second inclined portion 504 extending inclined from a lower end of the second support portion 503 toward an upper end of the third support portion 505. The lower end of the third support portion 505 may include a third inclined portion 506 and a lower end portion 507. 9, the lens barrel 500 extends from the vertical outer surface S51 of the first support part 501 along an inclined surface S52 to the vertical outer surface S53 of the second support part 503, and from the vertical outer surface S53 of the second support part 503 along an outwardly inclined surface S54 to the vertical outer surface S55 of the third support part 505. The lens barrel 500 also extends from the vertical outer surface S55 of the third support part 505 along an inclined outer surface S56 to the vertical outer surface S57 of the lower end part 507. At least one or all of the optical filter 196, the cover glass 194, and / or the image sensor 192 are disposed inside the lower end part 507. The lens barrel 500 has a first outer diameter of the first support part 501 based on the optical axis Lz, and the first outer diameter is the diameter of the lens barrel 500 at a position where the upper part of the first flange part 111A of the first lens 111 contacts the optical axis Lz. The straight line K1 shown in FIG.

[0082] The lens barrel 500 has a second outer diameter of the second support portion 503 based on the optical axis Lz. The second outer diameter is the diameter of the lens barrel 500 at a position where the upper part of the second flange portion 113A of the second lens 113 contacts the optical axis Lz. The diameter of the lens barrel 500 is indicated by a line K2 in FIG. 7. The lens barrel 500 has a third outer diameter of the third support portion 505 based on the optical axis Lz. The third outer diameter is the diameter of the lens barrel 500 at a position where the uppermost surface of the third flange portion 115A of the third lens 115 contacts the optical axis Lz. That is, the diameter of the lens barrel 500 is indicated by a line K3 in FIG. 8. The second outer diameter may be larger than the first outer diameter and smaller than the third outer diameter. That is, looking at the radii on the optical axis Lz, the second radius Z1 may be greater than the first radius Z1 and less than the third radius Z3. Here, the fourth outer diameter of the lower end 507 of the lens barrel 500 may be greater than the first, second, and third outer diameters, may be the largest in the lower barrel portion 510, and may be less than the outer diameter of the upper barrel portion 550.

[0083] The outer diameter of the lens barrel 500 at the position where the upper portion of the image sensor 192 or the optical filter 196 contacts the lens barrel 500, i.e., the lower end 507, is a fourth outer diameter. The third outer diameter may be smaller than the fourth radius and larger than the second outer diameter. The lower barrel portion 510 has a substantially uniform thickness, and may have a region with a uniform thickness and a region with a smaller non-uniform thickness. The thicknesses B1, B2, and B3 of the first, second, and third support portions 501, 503, and 505 may be the same, and may be equal to or less than 0.6 mm, for example, within a range of 0.5 mm ±0.05 mm. At least one of the thicknesses B1, B2, and B3 of the first, second, and third support portions 501, 503, and 505 may have a different thickness.

[0084] The thickness of the upper portion 509, which protrudes into the barrel to guide the upper periphery of the first lens 111, i.e., the first flange portion 111A, of the first support portion 501, is a maximum thickness B4 and may be 0.8 mm or more, for example, in the range of 0.8 mm to 1.2 mm. The upper portion 509 having such a maximum thickness extends in an inclined manner from the vertical outer surface S51 of the first support portion 501 to the floor portion 553 of the upper barrel portion 550, and the upper portion 509 is the upper portion of the lower barrel portion 510, and extends vertically from the upper end of the inclined outer surface to the first support portion 501. The vertical outer surface of the upper portion 509 is the portion where the periphery of the first lens 111 is disposed. Here, the thickness B5 of the inclined upper portion 509 extending from the first support portion 501 to the upper barrel portion 550 and the thicknesses B6 and B7 of the first and second inclined portions 502 and 504 are either the same or within a range of 0.6 mm or less, for example, 0.5 mm ± 0.05 mm. The thickness B8 of the lower end portion 507 of the lens barrel 500 is either the same as the thicknesses B1 and B6 or within a range of 0.6 mm or less, for example, 0.5 mm ± 0.05 mm. By providing the lens barrel 500, i.e., the lower barrel portion 510, with a uniform thickness, problems such as air bubbles penetrating the barrel during lens injection molding and reducing heat dissipation due to the air bubbles can be solved, lens stress can be suppressed, and lens deformation can be minimized. Here, as shown in FIG. 12, lens deformation can be minimized at the periphery of the lens, improving optical performance (MTF). Figure 12(A) shows a comparative example, which has a barrel shape similar to Figures 11(A) and 12(A), and Figure 12(B) shows an example in which the lens barrel of the present invention is used, which shows that the optical performance (MTF) is improved by more than 30% compared to the comparative example. The thickness of the lens barrel refers to the vertical distance from one surface to the other.

[0085] 7, a horizontal line K1 at the upper end of the first flange portion 111A of the first lens 111 that contacts the lens barrel is located at a boundary portion M1 between the vertical outer surface S51 and the inclined surface S52. Because thermal expansion of the first lens 111 progresses horizontally downward due to the convexity of the first surface S1 and the concavity of the second surface S2, the line K1 and the boundary portion M1 may overlap. A horizontal line K2 at the upper end of the second flange portion 113A of the second lens 113 that contacts the lens barrel is located higher than a boundary portion M2 between the vertical outer surface S53 and the inclined surface S54. Because thermal expansion of the second lens 113 progresses horizontally upward due to the concavity of the third surface S3 and the convexity of the fourth surface S4, the line K2 is located above the boundary portion M2.

[0086] 8, a horizontal line K3 at the upper end of the third flange portion 115A of the third lens 115, which contacts the lens barrel, is positioned higher than a boundary portion M3 between the vertical outer surface S55 and the inclined surface S56. Such line K3 has one or more inflection points due to the convexity of the fifth surface S5 and the concavity of the sixth surface S6 of the third lens 115, and therefore thermal expansion proceeds in a horizontal direction, so line K3 is positioned higher than boundary portion M3.

[0087] 9, based on a straight line Lz3 perpendicular to the outer surface of the lower end 507 of the lens barrel 500, the first support portion 501 may have a first depth G1, the second support portion 503 may have a second support portion G2, and the third support portion 505 may have a third depth G3. The depths may have a relationship of G1>G2>G3.

[0088] Figure 10 shows stress (unit: MPa) for a comparative example and the invention. The comparative example in Figure 10(A) has a structure in which the outer surfaces of the flanges of the first, second, and third lenses are in contact with the inner surface of the lens barrel as vertical surfaces. Figure 10(B) shows an example of contact between flanges 111A, 113A, and 115A of the first, second, and third lenses in Figures 1 to 3 and inner wall 511 of lens barrel 500.

[0089] 10A and 10B show that the stress values ​​for the comparative example and the invention are more different around the optical axis than around the optical axis ST5, ST6, and ST7 at the outside of the first flange ST1, the optical axis periphery ST2 of the third surface S3 of the second lens, and the optical axis periphery S3 of the fifth surface S3 of the third lens. The stress distribution for the invention is shown in FIG. 10B, where ST1 is 3.3, ST2 is 3.4, and ST3 is 4.6, while the comparative example is shown in FIG. 10B, where ST1 is 5.0, ST2 is 4.8, and ST3 is 5.2. This indicates that the stress values ​​for the invention are lower than those for the comparative example. Furthermore, using the second lens as a reference, the stress values ​​for the invention are lower than those for the comparative example.

[0090] FIG. 11 shows the strain (unit: μm / μm) of the comparative example and the invention. Comparing the strain values ​​at SN1, SN2, and SN3 around the optical axis in FIGS. 11A and 11B, it can be seen that the invention is lower than the comparative example. It can also be seen that there is no difference in the strain values ​​at optical axis positions SN4, SN5, SN6, and SN7 of each lens between the comparative example and the invention. Regarding the strain of each lens, in FIG. 11B for the invention, SN1 is 1.06, SN2 is 1.41, and SN3 is 2.2, while in FIG. 11A for the comparative example, SN1 is 1.5, SN2 is 1.6, and SN3 is 2.7.

[0091] In the optical system according to the first embodiment of the present invention, the angle of view (diagonal) may be 70 degrees or less, for example, in the range of 50 to 70 degrees. In the optical system, the distance TTL between the image sensor 190 and the vertex of the first lens 111 may be 11 mm or less, and the wavelength of the light used may be in the range of 870 nm to 1000 nm. Figures 12 (A) and (B) are graphs showing the diffraction MTF (Modulation Transfer Function) at high temperatures for the optical system of the comparative example and the optical system of the present invention, and show that the MTF reduction in spatial frequency for the optical system of the present invention is 30% or less compared to the comparative example.

[0092] 13 and 14 are side cross-sectional views illustrating a camera module according to a second embodiment. Specifically, FIG. 13 is a cross-sectional view illustrating the state of the camera module at a second temperature higher than the first temperature of the camera module of FIG. 1, and FIG. 3 is a cross-sectional view illustrating the state of the camera module at a third temperature lower than the first temperature. In the description of the second embodiment, the same configuration as in the first embodiment can include the description of the first embodiment disclosed above.

[0093] The lenses of the lens unit 100 housed inside the lens barrel 200 are disposed adjacent to the inner wall 511. Specifically, the lenses of the lens unit 100 housed inside the lens barrel 200 are in contact with the inner wall 511 or are spaced apart from it by a distance taking into account tolerances. The lens barrel 500 may include metal or plastic. The thermal expansion coefficient represents the dimensional change of an object with respect to a temperature change and may be defined as a one-dimensional linear expansion coefficient, a two-dimensional area expansion coefficient, a three-dimensional volume expansion coefficient, etc., depending on the standard. The lens barrel 500 may have a linear expansion coefficient (CTE) in a range that varies depending on the material forming the barrel. The linear expansion coefficient is a characteristic inherent to a material, and the lens barrel 500 may have a linear expansion coefficient in a range that varies depending on the material forming the lens barrel 500. For example, the lens barrel 500 may have a linear expansion coefficient of 100 ppm / °C or less. Specifically, the lens barrel 500 may have a linear expansion coefficient of 80 ppm / °C or less. More specifically, the lens barrel 500 may have a linear expansion coefficient of 10 ppm / °C to 80 ppm / °C.

[0094] The linear expansion coefficient of the lens barrel 500 may be the same as or different from the linear expansion coefficient of the lens of the lens unit 100. If the linear expansion coefficient of the lens barrel 500 is different from the linear expansion coefficient of the lens of the lens unit 100, the deformation amounts of the lens barrel 500 and the lens of the lens unit 100 due to temperature changes will differ. As a result, a gap may be generated between the lens of the lens unit 100 housed inside the lens barrel 500 and the lens barrel 500, corresponding to the difference in the deformation amounts. That is, due to the difference in the expansion or contraction amounts of the lens and the lens barrel 500, the lens may be spaced from the side wall of the lens barrel 500, resulting in a gap between the inner wall 511 of the lens barrel 500 and the lens. This may cause decentering of the lens unit, resulting in degradation of the optical characteristics of the camera module. Therefore, the camera module according to the embodiment may set the linear expansion coefficient of the lens barrel 500 to minimize the decentering of the lens unit, defined by the gap between the inner wall 511 of the lens barrel 500 and the lens.

[0095] The linear expansion coefficient of the lens barrel 500 will be described in detail below.

[0096] The lens unit 100 may include a plurality of lenses. More specifically, the lens unit 100 may include a plurality of lenses sequentially arranged in the lens barrel 500. The lens unit 100 may include at least three lenses. The number of lenses of the lens unit 100 included in the camera module 1000 may vary depending on the device and environment to which the camera module including the camera module 1000 is applied.

[0097] 13 and 14, the lens unit 100 includes three lenses, namely, a first lens 111, a second lens 113, and a third lens 115. However, the lens unit 100 of the second embodiment is not limited to three lenses and may include two or more lenses. For example, the lens unit 100 may include a plurality of lenses having different linear expansion coefficients. When the lens unit 100 includes two lenses, the lenses may have different linear expansion coefficients. Alternatively, when the lens unit 100 includes three or more lenses, the lenses may have different linear expansion coefficients. Alternatively, when the lens unit 100 includes three or more lenses, some of the three or more lenses may have the same linear expansion coefficient, and the remaining lenses may have different linear expansion coefficients.

[0098] For convenience of explanation, the following description will focus on a case where the lens unit 100 includes a first lens 111, a second lens 113, and a third lens 115. That is, the description will focus on a case where the lens unit 100 includes three or more lenses, each having a different linear expansion coefficient, or a case where some of the three or more lenses have the same linear expansion coefficient and the remaining lenses have different linear expansion coefficients. The first lens 111, the second lens 113, and the third lens 115 are sequentially arranged along an optical axis Lz of the camera module 1000. For example, the first lens 111, the second lens 113, and the third lens 115 are sequentially arranged inside the lens barrel 500 based on the direction of movement of light moving along the optical axis Lz.

[0099] The first to third lenses 111, 113, and 115 may have first to third effective areas, respectively, and first to third non-effective areas outside the first to third effective areas. The first to third non-effective areas may be areas of first to third flange portions 111A, 113A, and 115. A first flange portion 111A, which is the first non-effective area of ​​the first lens 111, may contact a first inner wall 51 of the lens barrel 500. A second flange portion 113A, which is the second non-effective area of ​​the second lens 113, may contact a second inner wall 52 of the lens barrel 500. A third flange portion 115A of the third lens 115 may contact a third inner wall 53 of the lens barrel 500.

[0100] The first lens 111, the second lens 113, and the third lens 115 may include at least one of glass and plastic. For example, the first lens 111, the second lens 113, and the third lens 115 may all be glass lenses, all be plastic lenses, or include both glass and plastic lenses. For convenience of explanation, the first lens 111 will be described as a glass lens, and the second lens 113 and the third lens 115 will be described as a plastic lens.

[0101] The first lens 111, the second lens 113, and the third lens 115 may have various coefficients of linear expansion (CTE) within a predetermined range depending on the material forming the lens. That is, the first lens 111, the second lens 113, and the third lens 115 may have coefficients of linear expansion within a predetermined range depending on the material forming the lens. More specifically, the coefficient of linear expansion of the first lens 111, which is a glass lens, may be different from the coefficients of linear expansion of the second lens 113 and the third lens 115, which are plastic lenses. The coefficients of linear expansion of the second lens 113 and the third lens 115, which are plastic lenses, may be the same or different. That is, even if the second lens 113 and the third lens 115 are all made of plastic materials, the coefficients of linear expansion of the second lens 113 and the third lens 115 may be the same or different depending on the composition of the resin composition forming the plastic.

[0102] The first lens 111, the second lens 113, and the third lens 115 may have a linear expansion coefficient of more than 0 ppm / °C to 100 ppm / °C or less. Specifically, the first lens 111, the second lens 113, and the third lens 115 may have a linear expansion coefficient of more than 0 ppm / °C to 80 ppm / °C or less. More specifically, the first lens 111, the second lens 113, and the third lens 115 may have a linear expansion coefficient of 5 ppm / °C to 80 ppm / °C.

[0103] As described above, the lens barrel 500, the first lens 111, the second lens 113, and the third lens 115 may have the same or different linear expansion coefficients. For example, the lens barrel 500 may have a different linear expansion coefficient from at least one of the first lens 111, the second lens 113, and the third lens 115. As a result, the lens barrel 500, the first lens 111, the second lens 113, and the third lens 115 may have different deformation amounts due to temperature changes. For example, as shown in FIG. 13 , when the camera module is in a first mode in which the temperature changes from a first temperature to a second temperature, the first lens 111 and the first inner wall 51 may be spaced apart by a first distance G4. In this case, the first mode may be defined as a mode in which the temperature changes from a first temperature to a second temperature higher than the first temperature. In this case, the first temperature may be defined as a room temperature between 20°C and 30°C, and the second temperature may be defined as a high temperature between 80°C and 105°C. For example, the first temperature may be 25°C and the second temperature may be 105°C.

[0104] The expansion and contraction amounts of the lens barrel 500 can be defined by Equation 1 above.

[0105] [Formula 1] Barrel expansion amount = barrel inner wall length x temperature change x barrel linear expansion coefficient Amount of barrel shrinkage = length of barrel inner wall x temperature change x linear expansion coefficient of barrel

[0106] In Equation 1, the length of the inner wall of the barrel can be defined as the minor width of the inner wall of the lens barrel (the inner diameter of the barrel), and in the specification, x represents multiplication.

[0107] The lens expansion and contraction amounts of the lens unit 100 can be defined by the following Equation 2.

[0108] [Formula 2] Lens expansion amount: Lens length x temperature change x linear expansion coefficient of lens Lens contraction amount: Lens length x temperature change x linear expansion coefficient of lens

[0109] In Equation 2, the length of the lens includes the effective area and the ineffective area of ​​the lens, and can be defined as the diameter of the lens in a direction parallel to the length of the inner wall of the lens barrel.

[0110] When the temperature of the camera module changes from the first temperature to the second temperature, which is higher, the lens and the lens barrel 500 may expand by the magnitudes of Equations 1 and 2, respectively. At this time, if the linear expansion coefficient of a glass material is smaller than the linear expansion coefficient of the lens barrel 500, the amount of expansion of the lens barrel 500 is greater than the amount of expansion of the first lens 111 including the glass material. Thus, when the temperature of the camera module changes from the first temperature to the second temperature, the first lens 111 and the first inner wall 51 may be spaced apart by a first distance G4.

[0111] 14, in the second mode in which the camera module changes temperature from a first temperature to a third temperature, which is lower, the second lens 113 and the second inner wall 52 may be spaced apart by a second distance G5, and the third lens 115 and the third inner wall 53 may be spaced apart by a third distance G6. In this case, the second mode may be defined as a mode in which the temperature changes from the first temperature to a third temperature that is lower than the first temperature. The first temperature may be defined as 20°C to 30°C, and the third temperature may be defined as a lower temperature, i.e., -40°C to -30°C. For example, the first temperature may be 25°C, and the third temperature may be -40°C.

[0112] When the camera module changes from the first temperature to the third temperature, the lens and the lens barrel 500 may contract by the magnitudes of Equations 1 and 2, respectively. At this time, if the linear expansion coefficient of plastic is larger than the linear expansion coefficient of the lens barrel 500, the contraction amount of the lens barrel 500 will be smaller than the contraction amount of the second lens 113 and the third lens 115, which include plastic. Thus, when the camera module changes from the first temperature to the third temperature, the second lens 113 and the second inner wall 52 may be spaced apart by a second distance G5, and the third lens 115 and the third inner wall 53 may be spaced apart by a third distance G6.

[0113] When the optical module changes from the first temperature to the second temperature or the third temperature, a gap is generated between the first lens 111, the second lens 113, and the third lens 115 housed inside the lens barrel 500 and the inner wall 511 of the lens barrel 500 by the difference in deformation amount, and as a result, the first lens 111, the second lens 113, and the third lens 115 are decentered by the gap dimension, thereby degrading the optical characteristics of the camera module. Therefore, in the camera module according to the embodiment, the linear expansion coefficients and sizes of the first lens 111, the second lens 113, and the third lens 115 may be set to minimize the decentering of the first lens 111, the second lens 113, and the third lens 115. The linear expansion coefficients and sizes of the first lens 111, the second lens 113, and the third lens 115 will be described in detail below.

[0114] Hereinafter, the linear expansion coefficients of the lenses and the barrels that can minimize the decentering of the camera module 1000 will be described. The linear expansion coefficients of the first lens 111, the second lens 113, and the third lens 115 may be the same or different. More specifically, the linear expansion coefficient of the first lens 111 may be different from the linear expansion coefficients of the second lens 113 and the third lens 115. That is, since the first lens 111 includes a different material from the second lens 113 and the third lens 115, the linear expansion coefficient of the first lens 111 may be different from the linear expansion coefficients of the second lens 113 and the third lens 115. The linear expansion coefficients of the second lens 113 and the third lens 115 may be the same or different. For example, if the second lens 113 and the third lens 115 include compositions having the same composition and composition ratio, the linear expansion coefficients of the second lens 113 and the third lens 115 may be the same. In addition, when the second lens 113 and the third lens 115 contain compositions having different compositions or different composition ratios, the linear expansion coefficient of the second lens 113 and the linear expansion coefficient of the third lens 115 may be different.

[0115] The first lens 111 may have a linear expansion coefficient within a set range. Specifically, the first lens 111 may have a linear expansion coefficient of 20 ppm / °C or less. More specifically, the first lens 111 may have a linear expansion coefficient of greater than 0 ppm / °C to 15 ppm / °C. More specifically, the first lens 111 may have a linear expansion coefficient of greater than 0 ppm / °C to 10 ppm / °C. Because the first lens 111 includes glass, it is difficult to achieve a linear expansion coefficient of the first lens 111 exceeding 20 ppm / °C due to the characteristics of the material. Furthermore, if the linear expansion coefficient of the first lens 111 exceeds 20 ppm / °C, the refractive index, Abbe number, etc. of the first lens 111, which is disposed closest to the object in the camera module, may change, resulting in degradation of the optical characteristics of the camera module.

[0116] The second lens 113 may have a linear expansion coefficient within a predetermined range. Specifically, the second lens 113 may have a linear expansion coefficient of 80 ppm / °C or less. More specifically, the second lens 113 may have a linear expansion coefficient of 40 ppm / °C to 70 ppm / °C. More specifically, the second lens 113 may have a linear expansion coefficient of 50 ppm / °C to 60 ppm / °C. Because the second lens 113 includes plastic, it is difficult to realize a linear expansion coefficient of the second lens 113 exceeding 80 ppm / °C due to the characteristics of the material. Furthermore, if the linear expansion coefficient of the second lens 113 exceeds 80 ppm / °C, the refractive index, Abbe number, etc. of the second lens 113 disposed between the first lens 111 and the third lens 115 in the camera module will change, degrading the optical characteristics of the camera module. The third lens 115 may have a linear expansion coefficient within a predetermined range. Specifically, the third lens 115 may have a linear expansion coefficient of 80 ppm / °C or less. More specifically, the third lens 115 may have a linear expansion coefficient of 40 ppm / °C to 70 ppm / °C. Still more specifically, the third lens 115 may have a linear expansion coefficient of 50 ppm / °C to 60 ppm / °C.

[0117] The second lens 113 and the third lens 115 may have the same linear expansion coefficient within the set range. Alternatively, the second lens 113 and the third lens 115 may have different linear expansion coefficients within the set range. Because the third lens 115 includes plastic, it is difficult to achieve a linear expansion coefficient of the third lens 115 exceeding 80 ppm / °C due to the characteristics of the material. In addition, if the linear expansion coefficient of the third lens 115 exceeds 80 ppm / °C, the refractive index, Abbe number, etc. of the third lens 115, which is disposed closest to the image sensor 192 in the camera module, may change, resulting in degradation of the optical characteristics of the camera module.

[0118] The first lens 111, the second lens 113, and the third lens 115 may have a size within a predetermined range. More specifically, the first lens 111, the second lens 113, and the third lens 115 may have a lens diameter within a predetermined range. Here, the lens diameters of the first lens 111, the second lens 113, and the third lens 115 may be defined as diameters including the effective area and the non-effective area of ​​each lens. More specifically, the diameter of the first lens 111 may be defined as the sum of the diameter of the first effective area and the diameter of the first flange portion, the diameter of the second lens 113 may be defined as the sum of the diameter of the second effective area and the diameter of the second flange portion, and the diameter of the third lens 115 may be defined as the sum of the diameter of the third effective area and the diameter of the third flange portion.

[0119] The diameter A1 of the first lens 111 may be 5 mm or less. Specifically, the diameter A1 of the first lens 111 may be 3 mm to 5 mm. More specifically, the diameter A1 of the first lens 111 may be 3.2 mm to 4.4 mm. If the diameter A1 of the first lens 111 exceeds 5 mm, the amount of expansion or contraction of the first lens 111 increases at high or low temperatures due to the increased diameter of the first lens 111, and the area where the first lens 111 is separated from the sidewall of the lens barrel 500 increases. As a result, the overall decentering of the camera module increases, deteriorating the optical characteristics of the camera module.

[0120] The diameter A2 of the second lens 113 may be 10 mm or less. Specifically, the diameter A2 of the second lens 113 may be 3 mm to 9 mm. More specifically, the diameter A2 of the second lens 113 may be 4.5 mm to 8 mm. If the diameter A2 of the second lens 113 exceeds 10 mm, the amount of expansion or contraction of the second lens 113 at high or low temperatures increases due to the increased diameter of the second lens 113, and the area where the second lens 113 is separated from the sidewall of the lens barrel 500 increases. As a result, the overall decentering of the camera module increases, deteriorating the optical characteristics of the camera module.

[0121] The diameter A3 of the third lens 115 may be 10 mm or less. Specifically, the diameter A3 of the third lens 115 may be 3 mm to 9 mm. More specifically, the diameter A3 of the third lens 115 may be 4.5 mm to 8 mm. If the diameter A3 of the third lens 115 exceeds 10 mm, the amount of expansion or contraction of the third lens 115 at high or low temperatures increases due to the increased diameter of the third lens 115, and the area where the third lens 115 is separated from the sidewall of the lens barrel 500 increases. As a result, the overall decentering of the camera module increases, deteriorating the optical characteristics of the camera module.

[0122] The diameters of the second lens 113 and the third lens 115 may be the same within the set range, or may be different within the set range. That is, the second lens 113 and the third lens 115 are formed to have the same or different diameters in consideration of the optical characteristics of the camera module.

[0123] The linear expansion coefficient of the lens barrel 500 may be different from the linear expansion coefficients of the first lens 111, the second lens 113, and the third lens 115. More specifically, the linear expansion coefficient of the lens barrel 500 may be greater than the linear expansion coefficient of the first lens 111. Furthermore, the linear expansion coefficient of the lens barrel 500 may be equal to or smaller than the linear expansion coefficients of the second lens 113 and the third lens 115. Thus, when the camera module changes from room temperature to a high temperature, the amount of expansion of the lens barrel 500 becomes greater than the amount of expansion of the first lens 111, so that the first lens 111 may be spaced apart from the first inner wall 51 of the lens barrel 500. When the camera module changes from room temperature to low temperature, the contraction amount of the lens barrel 500 becomes smaller than the contraction amount of the second lens 111 and the third lens 115, so the second lens 113 can be separated from the second inner wall 52 of the lens barrel 500, and the third lens 113 can be separated from the third inner wall 53 of the lens barrel 500.

[0124] The lens barrel 500 is determined depending on the linear expansion coefficients of the lenses and the diameters of the lenses. Specifically, the linear expansion coefficient of the lens barrel 500 may be 60 ppm / °C or less, taking into account the linear expansion coefficients of the lenses and the diameters of the lenses. More specifically, when the linear expansion coefficient of the first lens is greater than 0 ppm / °C to 20 ppm / °C and the linear expansion coefficients of the second and third lenses are 50 ppm / °C to 60 ppm / °C, the linear expansion coefficient of the lens barrel 500 may be 29 ppm / °C to 60 ppm / °C. More specifically, the linear expansion coefficient of the lens barrel 500 may be 29 ppm / °C to 50 ppm / °C. More specifically, the linear expansion coefficient of the lens barrel 500 may be 36 ppm / °C to 50 ppm / °C. More specifically, when the linear expansion coefficient of the first lens is greater than 0 ppm / °C to 10 ppm / °C and the linear expansion coefficients of the second and third lenses are 50 ppm / °C to 60 ppm / °C, the linear expansion coefficient of the lens barrel 500 may be 31 ppm / °C to 60 ppm / °C. More specifically, the linear expansion coefficient of the lens barrel 500 may be 39 ppm / °C to 60 ppm / °C. Even more specifically, the linear expansion coefficient of the lens barrel 500 may be 46 ppm / °C to 50 ppm / °C.

[0125] The range of the linear expansion coefficient of the lens barrel 500 corresponds to the linear expansion coefficients of the first, second, and third lenses when the diameter of the first lens is 4.3 mm and the diameters of the second and third lenses are 6.5 mm. The embodiment is not limited thereto, and the linear expansion coefficient of the lens barrel may have various ranges depending on the diameters of the first, second, and third lenses and the linear expansion coefficients of the first, second, and third lenses. That is, in the camera module, the first lens 111 has a linear expansion coefficient of 20 ppm / °C or less, the second lens 113 has a linear expansion coefficient of 60 ppm / °C or less, and the third lens 115 has a linear expansion coefficient of 60 ppm / °C or less. Taking into consideration that the diameter of the first lens 111 is 5 mm or less, the diameter of the second lens 113 is 10 mm or less, and the diameter of the third lens 115 is 10 mm or less, the range of the linear expansion coefficient of the barrel may be set to minimize decentering of the lenses. Specifically, the camera module can set the linear expansion coefficient ranges of the lens barrel 500 so that the first gap G4 of the first lens 111 is 0 μm or more and 18 μm or less, the second gap G5 of the second lens 113 is 0 μm or more and 9 μm or less, and the third gap G6 of the third lens 115 is 0 μm or more and 9 μm or less. More specifically, the camera module can set the linear expansion coefficient ranges of the lens barrel 500 so that the first gap G4 of the first lens 111 is 0 μm or more and 15 μm or less, the second gap G5 of the second lens 113 is 0 μm or more and 6 μm or less, and the third gap G6 of the third lens 115 is 0 μm or more and 6 μm or less.

[0126] If the first distance G4 of the first lens 111 exceeds 18 μm, the optical characteristics are significantly degraded due to decentering of the lens unit 100. Also, if the second distance G5 of the second lens 113 and the third distance G6 of the third lens 115 exceed 9 μm, the optical characteristics are significantly degraded due to decentering of the lens unit 100. If the linear expansion coefficient of the lens barrel 500 exceeds 60 ppm / °C or less than 29 ppm / °C, the difference in the amount of expansion between the first lens 111 and the lens barrel 500 becomes too large at high temperatures, causing the first distance G4 of the first lens 111 to exceed 18 μm. Also, the difference in the amount of contraction between the second lens 113, the third lens 115 and the lens barrel 500 becomes too large at low temperatures, causing the second distance G5 of the second lens 113 and the third distance G6 of the third lens 115 to exceed 9 μm. As a result, the optical characteristics of the camera module 1000 including the lens unit 100 are degraded due to an increase in the overall decentering of the lens unit 100 .

[0127] Hereinafter, the second embodiment will be described in detail with reference to the heat dissipation members of the camera modules according to the second embodiment and the comparative example and the thermal characteristics of the heat dissipation members. The second embodiment is merely provided as an example to explain the present invention in more detail. Therefore, the present invention is not limited to the examples disclosed below.

[0128] [Example 1] A first lens, a second lens, and a third lens were disposed inside the lens barrel. A spacing adjustment member was disposed between the first lens, the second lens, and the third lens to maintain the distance between the lenses. The camera module was then subjected to temperature changes from 25°C to a low temperature of -40°C and a high temperature of 105°C, and the distances between the barrel inner wall 511 and the first, second, and third lenses were observed. The linear expansion coefficient of the first lens was 7.3 ppm / °C, the linear expansion coefficient of the second lens was 60 ppm / °C, and the linear expansion coefficient of the third lens was 60 ppm / °C. The diameter of the first lens was 3.2 mm, the diameter of the second lens was 4.8 mm, and the diameter of the third lens was 4.8 mm. The distances between the first lens, the second lens, and the third lens and the barrel inner wall 511 were measured while the linear expansion coefficient of the lens barrel was changed.

[0129] [Example 2] The distances between the first lens, the second lens, and the third lens and the barrel inner wall 511 were measured while changing the linear expansion coefficient of the lens barrel in the same manner as in Example 1, except that the diameter of the first lens was 4.39 mm.

[0130] [Example 3] The distances between the first lens, the second lens, and the third lens and the barrel inner wall 511 were measured while changing the linear expansion coefficient of the lens barrel, as in Example 1, except that the diameters of the second lens and the third lens were 8 mm.

[0131] [Example 4] The distances between the first lens, the second lens, and the third lens and the barrel inner wall 511 were measured while changing the linear expansion coefficient of the lens barrel, similarly to Example 1, except that the diameter of the first lens was 4.39 mm and the diameters of the second lens and the third lens were 8 mm.

[0132] [Example 5] The distances between the first lens, the second lens, and the third lens and the barrel inner wall 511 were measured while changing the linear expansion coefficient of the lens barrel, similarly to Example 1, except that the diameter of the first lens was 4.3 mm and the diameters of the second lens and the third lens were 6.5 mm.

[0133] [Example 6] The distances between the first lens, the second lens, and the third lens and the barrel inner wall 511 were measured while changing the linear expansion coefficient of the lens barrel in the same manner as in Example 1, except that the linear expansion coefficient of the first lens was 20 ppm / °C and the linear expansion coefficients of the second lens and the third lens were 50 ppm / °C.

[0134] [Example 7] The distances between the first lens, the second lens, and the third lens and the barrel inner wall 511 were measured while changing the linear expansion coefficient of the lens barrel, similarly to Example 1, except that the linear expansion coefficient of the first lens was 20 ppm / °C, the linear expansion coefficients of the second lens and the third lens were 50 ppm / °C, and the diameter of the first lens was 4.39 mm.

[0135] [Example 8] The distances between the first lens, the second lens, and the third lens and the barrel inner wall 511 were measured while changing the linear expansion coefficient of the lens barrel, similarly to Example 1, except that the linear expansion coefficient of the first lens was 20 ppm / °C, the linear expansion coefficients of the second lens and the third lens were 50 ppm / °C, and the diameters of the second lens and the third lens were 8 mm.

[0136] [Example 9] The distances between the first lens, the second lens, and the third lens and the barrel inner wall 511 were measured while changing the linear expansion coefficient of the lens barrel, similarly to Example 1, except that the linear expansion coefficient of the first lens was 20 ppm / °C, the linear expansion coefficients of the second lens and the third lens were 50 ppm / °C, the diameter of the first lens was 4.39 mm, and the diameters of the second lens and the third lens were 8 mm.

[0137] [Example 10] The distances between the first lens, the second lens, and the third lens and the barrel inner wall 511 were measured while changing the linear expansion coefficient of the lens barrel, similarly to Example 1, except that the linear expansion coefficient of the first lens was 20 ppm / °C, the linear expansion coefficients of the second lens and the third lens were 50 ppm / °C, the diameter of the first lens was 4.3 mm, and the diameters of the second lens and the third lens were 6.5 mm.

[0138] FIG. 15 is a table illustrating the linear expansion coefficients and diameters of the first to third lenses in Examples 1 to 10 of the second embodiment. FIG. 16 shows the values ​​of the expansion and contraction amounts of the first, second, and third lenses excluding the lens diameters in Examples 1 to 5 of FIG. 15, and the spacing between the first, second, and third lenses according to changes in the linear expansion coefficient of the lens barrel taking into account the diameters of the first, second, and third lenses in Examples 1 to 5.

[0139] In Figure 16, A represents the difference in the degree of expansion between the first lens and the lens barrel when the temperature changes from 25°C to 105°C, and A (mm) = temperature change (°C) × (barrel CTE (10 -6 mm / ℃)-1st lens CTE(10 -6 B is the difference in the degree of contraction between the second and third lenses and the lens barrel when the temperature changes from 25°C to -40°C, and B (mm) = temperature change (°C) x (barrel CTE (10 -6 mm / ℃)-2nd and 3rd lens CTE(10 -6mm / ℃) condition can be satisfied. C means the product of the first lens diameter and A, rounded to the second decimal place, and C (μm) = A × first lens diameter (mm) × 10 3 D means the product of the diameter of the second and third lenses and B, rounded to the second decimal place, and is given by D (μm) = B × diameter of the second and third lenses (mm) × 10 3 The above conditions can be satisfied.

[0140] FIG. 17 shows the values ​​of the expansion and contraction of the first lens, the second lens, and the third lens excluding the lens diameters in Examples 6 to 10 of FIG. 15, and the spacing between the first lens, the second lens, and the third lens according to the change in the linear expansion coefficient of the barrel taking into account the diameters of the first lens, the second lens, and the third lens in Examples 6 to 10.

[0141] In Figure 17, E represents the difference in the degree of expansion between the first lens and the lens barrel when the temperature changes from 25°C to 105°C, and E (mm) = temperature change (°C) × (barrel CTE (10 -6 mm / ℃)-1st lens CTE(10 -6 F (mm / ℃) is the difference in the degree of contraction between the second and third lenses and the lens barrel when the temperature changes from 25℃ to -40℃, and F (mm) = temperature change (℃) × (barrel CTE (10 -6 mm / ℃)-2nd and 3rd lens CTE(10 -6 mm / ℃) condition can be satisfied. G means the product of the first lens diameter and E, rounded to the second decimal place, and G (μm) = E × first lens diameter (mm) × 10 3 H means the product of the diameter of the second and third lenses and B, rounded to the second decimal place, and is expressed as H (μm) = F × diameter of the second and third lenses (mm) × 10 3 The above conditions can be satisfied.

[0142] 16, in the case of the camera module according to Example 1, when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 65 ppm / °C, the gap between the first lens and the lens barrel is 18 μm or less. When the linear expansion coefficient of the lens barrel is 41 ppm / °C to 60 ppm / °C, the gap between the second lens and the barrel and the third lens and the lens barrel is 9 μm or less. That is, when the linear expansion coefficient of the camera module according to Example 1 is 41 ppm / °C to 60 ppm / °C, the first lens, the second lens, and the third lens are set to decenters that do not affect the optical characteristics.

[0143] In the case of the camera module according to Example 2, it can be seen that the gap between the first lens and the lens barrel is 18 μm or less when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 50 ppm / °C. Also, it can be seen that the gap between the second lens and the lens barrel and the gap between the third lens and the lens barrel is 9 μm or less when the linear expansion coefficient of the lens barrel is 41 ppm / °C to 60 ppm / °C.

[0144] That is, in the camera module according to Example 2, when the linear expansion coefficient is 41 ppm / °C to 50 ppm / °C, the first lens, the second lens, and the third lens are set decentered so as not to affect the optical characteristics.

[0145] In the case of the camera module according to Example 3, it can be seen that when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 65 ppm / °C, the gap between the first lens and the barrel is 18 μm or less. When the linear expansion coefficient of the lens barrel is 49 ppm / °C to 60 ppm / °C, it can be seen that the gap between the second lens and the lens barrel and the gap between the third lens and the lens barrel is 9 μm or less. That is, it can be seen that in the camera module according to Example 3, when the linear expansion coefficient is 49 ppm / °C to 50 ppm / °C, the first lens, the second lens, and the third lens are set to decenters that do not affect the optical characteristics.

[0146] In the case of the camera module according to Example 4, it can be seen that when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 50 ppm / °C, the gap between the first lens and the lens barrel is 18 μm or less. Also, when the linear expansion coefficient of the lens barrel is 49 ppm / °C to 60 ppm / °C, it can be seen that the gap between the second lens and the lens barrel and the gap between the third lens and the lens barrel is 9 μm or less. That is, it can be seen that in the camera module according to Example 4, when the linear expansion coefficient is 49 ppm / °C to 50 ppm / °C, the first lens, the second lens, and the third lens are set to decenters that do not affect the optical characteristics.

[0147] In the case of the camera module according to Example 5, when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 60 ppm / °C, the gap between the first lens and the barrel is 0 μm or more and 18 μm or less. Furthermore, when the linear expansion coefficient of the lens barrel is 39 ppm / °C to 60 ppm / °C, the gap between the second lens and the lens barrel and the gap between the third lens and the lens barrel is 0 μm or more and 9 μm or less. That is, in the camera module according to Example 5, when the linear expansion coefficient is 39 ppm / °C to 60 ppm / °C, the first lens, the second lens, and the third lens are decentered so as not to affect the optical characteristics. More specifically, when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 50 ppm / °C, the gap between the first lens and the barrel is 15 μm or less. It can be seen that the gaps between the second lens and the lens barrel and between the third lens and the lens barrel are 5 μm or less when the linear expansion coefficient of the lens barrel is 46 ppm / °C to 60 ppm / °C. That is, it can be seen that in the camera module according to Example 5, when the linear expansion coefficient is 46 ppm / °C to 50 ppm / °C, the first lens, the second lens, and the third lens are set to decenters that do not affect the optical characteristics.

[0148] 17, in the case of the camera module according to Example 6, when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 70 ppm / °C, the gap between the first lens and the lens barrel is 18 μm or less. Also, when the linear expansion coefficient of the lens barrel is 31 ppm / °C to 50 ppm / °C, the gap between the second lens and the lens barrel and the gap between the third lens and the lens barrel is 9 μm or less. That is, in the camera module according to Example 6, when the linear expansion coefficient is 31 ppm / °C to 50 ppm / °C, the first lens, the second lens, and the third lens are decentered so as not to affect the optical characteristics.

[0149] In the case of the camera module according to Example 7, it can be seen that when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 62 ppm / °C, the gap between the first lens and the lens barrel is 18 μm or less. When the linear expansion coefficient of the lens barrel is 31 ppm / °C to 50 ppm / °C, it can be seen that the gap between the second lens and the lens barrel and the gap between the third lens and the lens barrel is 9 μm or less. That is, it can be seen that in the camera module according to Example 7, when the linear expansion coefficient is 31 ppm / °C to 50 ppm / °C, the first lens, the second lens, and the third lens are set to decenters that do not affect the optical characteristics.

[0150] In the case of the camera module according to Example 8, it can be seen that when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 70 ppm / °C, the gap between the first lens and the barrel is 18 μm or less. Also, when the linear expansion coefficient of the lens barrel is 39 ppm / °C to 50 ppm / °C, it can be seen that the gap between the second lens and the lens barrel and the gap between the third lens and the lens barrel is 9 μm or less. That is, it can be seen that in the camera module according to Example 8, when the linear expansion coefficient is 39 ppm / °C to 50 ppm / °C, the first lens, the second lens, and the third lens are set to decenters that do not affect the optical characteristics.

[0151] In the case of the camera module according to Example 9, it can be seen that when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 62 ppm / °C, the gap between the first lens and the lens barrel is 18 μm or less. When the linear expansion coefficient of the lens barrel is 39 ppm / °C to 50 ppm / °C, it can be seen that the gap between the second lens and the lens barrel and the gap between the third lens and the lens barrel is 9 μm or less. That is, it can be seen that in the camera module according to Example 9, when the linear expansion coefficient is 39 ppm / °C to 50 ppm / °C, the first lens, the second lens, and the third lens are set to decenters that do not affect the optical characteristics.

[0152] In the case of the camera module according to Example 10, it can be seen that when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 70 ppm / °C, the gap between the first lens and the lens barrel is 18 μm or less. It can also be seen that when the linear expansion coefficient of the lens barrel is 29 ppm / °C to 50 ppm / °C, the gap between the second lens and the lens barrel and the gap between the third lens and the lens barrel is 9 μm or less. That is, in the camera module according to Example 10, when the linear expansion coefficient is 29 ppm / °C to 50 ppm / °C, the first lens, the second lens, and the third lens are decentered so as not to affect the optical characteristics. More specifically, it can be seen that when the linear expansion coefficient of the lens barrel is 20 ppm / °C to 63 ppm / °C, the gap between the first lens and the lens barrel is 15 μm or less. Furthermore, it can be seen that the gaps between the second lens and the lens barrel and between the third lens and the lens barrel are 5 μm or less when the linear expansion coefficient of the lens barrel is 36 ppm / ° C. to 50 ppm / ° C. That is, it can be seen that in the camera module according to Example 10, when the linear expansion coefficient is 36 ppm / ° C. to 50 ppm / ° C., the first lens, the second lens, and the third lens are set to decenters that do not affect the optical characteristics.

[0153] The camera module according to the second embodiment can set the linear expansion coefficient of the barrel to minimize lens decentering depending on the lens material and diameter. Specifically, the linear expansion coefficient, which is an inherent property of a material, differs depending on the lens material. In this case, due to differences in the linear expansion coefficients between the lenses included in the camera module and between the lenses and the barrel, decentering of the lenses at the inner wall 511 of the lens barrel can occur due to differences in the amounts of expansion and contraction when the camera module changes from a high temperature state to a low temperature state. Therefore, the magnitude of the difference in the amounts of expansion and contraction between the lenses and the barrel can be controlled by taking into account the range of the linear expansion coefficient of each lens depending on the lens material and the lens diameter. That is, the camera module according to the embodiment can set the range of the linear expansion coefficient of the barrel so that decentering occurring at high and low temperature states does not significantly affect the optical characteristics of the camera module. Therefore, by setting the camera module to have a barrel linear expansion coefficient within a range set according to the set linear expansion coefficient of the lens and the set diameter range, the decentering of the lens can be adjusted to a decentering range that does not significantly affect the optical characteristics of the camera module at high and low temperatures. Therefore, the camera module according to the second embodiment can maintain uniform operating performance in any of normal, high and low temperature conditions by minimizing the decentering range in both high and low temperature conditions.

[0154] Hereinafter, a camera module according to the third embodiment will be described with reference to FIGS.

[0155] Fig. 1 is a cross-sectional view of a camera module at a first temperature, Fig. 13 is a cross-sectional view of a camera module at a second temperature higher than the first temperature, and Fig. 14 is a cross-sectional view of a camera module at a third temperature lower than the first temperature. In the description of the third embodiment, the configuration disclosed above can be included in the third embodiment.

[0156] The first temperature may be room temperature, the second temperature may be a high temperature, and the third temperature may be a low temperature. In this case, the first temperature may be 20°C to 30°C, the second temperature may be 80°C to 105°C, and the third temperature may be -40°C to -30°C. For example, the first temperature may be 25°C, the second temperature may be 105°C, and the third temperature may be -40°C. For example, the lens barrel 500 may have a linear expansion coefficient of 100 ppm / °C or less. More specifically, the lens barrel 500 may have a linear expansion coefficient of 80 ppm / °C or less. More specifically, the lens barrel 500 may have a linear expansion coefficient of 10 ppm / °C to 80 ppm / °C. Even more specifically, the lens barrel 500 may have a linear expansion coefficient of 10 ppm / °C to 70 ppm / °C.

[0157] The linear expansion coefficient of the lens barrel 500 may be the same as or different from the linear expansion coefficient of the lenses of the lens unit 100. If the linear expansion coefficient of the lens barrel 500 is different from the linear expansion coefficient of the lenses of the lens unit 100, the deformation amounts of the lenses of the lens barrel 500 and the lens unit 100 due to temperature changes will be different. That is, the lenses of the lens barrel 500 and the lens unit 100 may contract or expand depending on temperature changes. For example, the lenses of the lens barrel 500 and the lens unit 100 may expand when the temperature changes from a first temperature to a second temperature, and may contract when the temperature changes from the first temperature to a third temperature. The lens barrel 500 and the lenses of the lens unit 100 have different linear expansion coefficients, which are inherent characteristics of materials, and therefore the degree of expansion and contraction at the second temperature and the third temperature will be different. As a result, a gap may be generated between the lens of the lens unit 100 housed inside the lens barrel 500 and the lens barrel 500, depending on the difference in deformation between the lens barrel 500 and the lens of the lens unit 100. That is, depending on the difference in the amount of expansion or contraction between the lens and the lens barrel 500, the lens may be spaced apart from the sidewall of the lens barrel 500, and a gap may be generated between the inner wall 511 of the lens barrel 500 and the lens.

[0158] As a result, the decentering of the lens of the lens unit is shifted, deteriorating the optical characteristics of the camera module. Therefore, in a camera module according to a third embodiment described below, the diameter range of the lens can be adjusted to a set range depending on the magnitude of the linear expansion coefficients of the lens barrel 500 and the lens, so as to minimize the decentering of the lens unit, which is defined by the gap between the inner wall 511 of the lens barrel 500 and the lens.

[0159] The diameter range of the lenses will be described in detail below. As shown in Figures 1, 13, and 14, the lens unit 100 may have two or more lenses, for example, a first lens 111, a second lens 113, and a third lens 115. That is, the following description will focus on the case where the lens unit 100 includes three lenses, each of which has a different linear expansion coefficient, or where some of the three or more lenses have the same or similar linear expansion coefficient and the remaining lenses have different linear expansion coefficients.

[0160] The first lens 111, the second lens 113, and the third lens 115 are sequentially arranged along an optical axis Lz of the camera module 1000. For example, the first lens 111, the second lens 113, and the third lens 115 are sequentially arranged inside the lens barrel 500 based on the moving direction of light moving along the optical axis Lz.

[0161] The first to third lenses 111, 113, and 115 may have first to third effective areas and first to third non-effective areas outside the first to third effective areas, respectively. The first to third non-effective areas may be areas of first to third flange portions 111A, 113A, and 115. A first flange portion 111A, which is the first non-effective area of ​​the first lens 111, may contact a first inner wall 51 of the lens barrel 500. A second flange portion 113A, which is the second non-effective area of ​​the second lens 113, may contact a second inner wall 52 of the lens barrel 500. A third flange portion 115A of the third lens 115 may contact a third inner wall 53 of the lens barrel 500.

[0162] The first lens 111, the second lens 113, and the third lens 115 may include at least one of glass and plastic. For example, the first lens 111, the second lens 113, and the third lens 115 may all be glass lenses, all be plastic lenses, or include both glass and plastic lenses. For convenience of explanation, the following description will be focused on the first lens 111 being a glass lens and the second lens 113 and the third lens 115 being plastic lenses.

[0163] The first lens 111, the second lens 113, and the third lens 115 may have a coefficient of linear expansion (CTE) within a predetermined range depending on the material forming the lens. That is, the first lens 111, the second lens 113, and the third lens 115 may have a coefficient of linear expansion within a predetermined range depending on the material forming the lens. More specifically, the coefficient of linear expansion of the first lens 111, which is a glass lens, may be different from the coefficient of linear expansion of the second lens 113 and the third lens 115, which are plastic lenses. The coefficient of linear expansion of the second lens 113 and the third lens 115, which are plastic lenses, may be the same or different. That is, even if the second lens 113 and the third lens 115 are all plastic lenses, the second lens 113 and the third lens 115 may have the same or different coefficients of linear expansion depending on the composition of the resin composition forming the plastic.

[0164] The first lens 111, the second lens 113, and the third lens 115 may have a linear expansion coefficient of more than 0 ppm / °C to 85 ppm / °C or less. Specifically, the first lens 111, the second lens 113, and the third lens 115 may have a linear expansion coefficient of more than 0 ppm / °C to 80 ppm / °C or less. More specifically, the first lens 111, the second lens 113, and the third lens 115 may have a linear expansion coefficient of 3 ppm / °C to 80 ppm / °C. As described above, the lens barrel 500 and the first lens 111, the second lens 113, and the third lens 115 may have the same or different linear expansion coefficients. For example, the lens barrel 500 may have a linear expansion coefficient different from that of at least one of the first lens 111, the second lens 113, and the third lens 115.

[0165] Therefore, the lens barrel 500, the first lens 111, the second lens 113, and the third lens 115 are deformed by different amounts due to temperature changes.

[0166] 13, in the first mode in which the camera module changes temperature from a first temperature to a second temperature, the first lens 111 and the first inner wall 51 may be spaced apart by a first distance G4. In this case, the first mode may be defined as a mode in which the temperature changes from a first temperature to a second temperature that is higher than the first temperature.

[0167] The expansion and contraction amounts of the lens barrel 500 can be calculated using Equation 1 above.

[0168] The lens expansion and contraction amounts of the lens unit 100 can be calculated using Equation 2 above.

[0169] 1 and 13, when the temperature of the camera module changes from the first temperature to the second temperature, the lens and the lens barrel 500 may expand by the magnitudes of Equations 1 and 2, respectively. At this time, if the linear expansion coefficient of glass is smaller than the linear expansion coefficient of the lens barrel 500, the amount of expansion of the lens barrel 500 becomes larger than the amount of expansion of the first lens 111 including the glass. Thus, when the temperature of the camera module changes from the first temperature to the second temperature, the first lens 111 and the first inner wall 51 may be spaced apart by a first distance G4.

[0170] 1 and 14, in the second mode in which the temperature of the camera module changes from a first temperature to a third temperature, the second lens 113 and the second inner wall 52 may be spaced apart by a second distance G5, and the third lens 115 and the third inner wall 53 may be spaced apart by a third distance G6. In this case, the second mode may be defined as a mode in which the temperature changes from the first temperature to a third temperature that is lower than the first temperature.

[0171] When the camera module changes from the first temperature to the third temperature, the lens and the lens barrel 500 may contract by the magnitudes of Equations 1 and 2, respectively. If the linear expansion coefficient of plastic is greater than the linear expansion coefficient of the lens barrel 500, the contraction amount of the lens barrel 500 will be smaller than the contraction amount of the second lens 113 and the third lens 115, which include plastic. Thus, when the camera module changes temperature from the first temperature to the third temperature, the second lens 113 and the second inner wall 52 may be spaced apart by a second distance G5, and the third lens 115 and the third inner wall 53 may be spaced apart by a third distance G6. When the temperature of the camera module changes from the first temperature to the second temperature or the third temperature, the distance between the first lens 111, the second lens 113, and the third lens 115 housed inside the lens barrel 500 and the inner wall 511 of the lens barrel 500 changes by the difference in the amount of deformation, and as a result, the first lens 111, the second lens 113, and the third lens 115 become decentered by the distance, thereby degrading the optical characteristics of the camera module.

[0172] Therefore, in the camera module of the third embodiment, the diameter ranges of the first lens 111, the second lens 113, and the third lens 115 can be set according to the linear expansion coefficients of the lens barrel 500, the first lens 111, the second lens 113, and the third lens 115 so as to minimize the decentering of the first lens 111, the second lens 113, and the third lens 115.

[0173] The ranges of the diameters of the first lens 111, the second lens 113, and the third lens 115 will be described in detail below.

[0174] The distance maintaining members 121, 123, 124, and 125 are disposed inside the lens barrel 500. More specifically, the distance maintaining members are disposed between the first lens 111, the second lens 113, and the third lens 115, respectively. More specifically, a first light-shielding film 121 is disposed between the first lens 111 and the second lens 113. A second light-shielding film 124 and / or a distance maintaining part 123 is disposed between the second lens 113 and the third lens 115. A support member 125 is disposed to maintain the distance between the lower part of the third lens 115 and the optical filter 196.

[0175] Flange portions 111A, 113A, and 115A, which are ineffective regions of the first lens 111, the second lens 113, and the third lens 115, are supported by the first light-shielding film 121, the second light-shielding film 124, the gap maintaining portion 123, and the support member 125. The gaps between the first lens 111, the second lens 113, and the third lens 115 are maintained within a range set by the gap maintaining members 121, 123, 124, and 125.

[0176] The spacing maintaining members 121, 123, 124, and 125 may include an opaque material. The spacing maintaining members 121, 123, 124, and 125 may include a material that does not transmit light, thereby preventing light from being transmitted and refracted in the non-effective areas of the first lens 111, the second lens 113, and the third lens 115.

[0177] The following describes the size of the lens and the linear expansion coefficient of the lens and barrel that can minimize decentering of the camera module 1000 due to temperature changes.

[0178] The linear expansion coefficients of the first lens 111, the second lens 113, and the third lens 115 may be the same or different. More specifically, the linear expansion coefficient of the first lens 111 may be different from the linear expansion coefficients of the second lens 113 and the third lens 115. That is, since the first lens 111 includes a different material from the second lens 113 and the third lens 115, the linear expansion coefficient of the first lens 111 may be different from the linear expansion coefficients of the second lens 113 and the third lens 115.

[0179] The linear expansion coefficient of the second lens 113 and the linear expansion coefficient of the third lens 115 may be the same or different. For example, when the second lens 113 and the third lens 115 contain compositions having the same composition and composition ratio, the linear expansion coefficient of the second lens 113 and the linear expansion coefficient of the third lens 115 may be the same. When the second lens 113 and the third lens 115 contain compositions having different compositions or different composition ratios, the linear expansion coefficient of the second lens 113 and the linear expansion coefficient of the third lens 115 may be different.

[0180] The first lens 111 may have a linear expansion coefficient within a set range. Specifically, the first lens 111 may have a linear expansion coefficient of 20 ppm / °C or less. More specifically, the first lens 111 may have a linear expansion coefficient of more than 0 ppm / °C to 25 ppm / °C. Still more specifically, the first lens 111 may have a linear expansion coefficient of 3 ppm / °C to 18 ppm / °C.

[0181] Because the first lens 111 includes a glass material, it is difficult to realize a linear expansion coefficient of the first lens 111 exceeding 20 ppm / ° C. due to the characteristics of the material. In addition, if the linear expansion coefficient of the first lens 111 exceeds 20 ppm / ° C., the refractive index, Abbe number, etc. of the first lens 111, which is disposed closest to the object in the camera module, change, degrading the optical characteristics of the camera module.

[0182] The second lens 113 may have a linear expansion coefficient within a set range. Specifically, the second lens 113 may have a linear expansion coefficient of 85 ppm / °C or less. More specifically, the second lens 113 may have a linear expansion coefficient of 55 ppm / °C to 85 ppm / °C. Even more specifically, the second lens 113 may have a linear expansion coefficient of 58 ppm / °C to 83 ppm / °C. Because the second lens 113 includes a plastic material, it is difficult to realize a linear expansion coefficient of the second lens 113 exceeding 85 ppm / °C due to the characteristics of the material. Furthermore, if the linear expansion coefficient of the second lens 113 exceeds 85 ppm / °C, the refractive index, Abbe number, etc. of the second lens 113 disposed between the first lens 111 and the third lens 115 in the camera module may change, thereby degrading the optical characteristics of the camera module.

[0183] The third lens 115 may have a linear expansion coefficient within a set range. Specifically, the third lens 115 may have a linear expansion coefficient of 85 ppm / °C or less. More specifically, the third lens 115 may have a linear expansion coefficient of 55 ppm / °C to 85 ppm / °C. Still more specifically, the third lens 115 may have a linear expansion coefficient of 58 ppm / °C to 83 ppm / °C.

[0184] The second lens 113 and the third lens 115 may have the same linear expansion coefficient within the set range, or may have different linear expansion coefficients within the set range.

[0185] Because the third lens 115 includes a plastic material, it is difficult to realize a linear expansion coefficient of the third lens 115 exceeding 85 ppm / ° C. due to the characteristics of the material. In addition, if the linear expansion coefficient of the third lens 115 exceeds 85 ppm / ° C., the refractive index, Abbe number, etc. of the third lens 115, which is disposed closest to the image sensor 192 in the camera module, will change, degrading the optical characteristics of the camera module.

[0186] The lens barrel 500 may have a coefficient of linear expansion within a set range. Specifically, the lens barrel 500 may have a coefficient of linear expansion of 80 ppm / °C or less. More specifically, the lens barrel 500 may have a coefficient of linear expansion of more than 0 ppm / °C to 80 ppm / °C. Still more specifically, the lens barrel 500 may have a coefficient of linear expansion of 10 ppm / °C to 70 ppm / °C.

[0187] Because the lens barrel 500 includes a plastic material, it is difficult to realize a linear expansion coefficient of the lens barrel 500 exceeding 80 ppm / ° C. Due to the characteristics of the material, if the linear expansion coefficient of the lens barrel 500 exceeds 80 ppm / ° C., the difference in the linear expansion coefficient between the lens barrel 500 accommodating the first lens 111, the second lens 113, and the third lens 115 in the camera module and the first lens 111, the second lens 113, and the third lens 115 increases, increasing the decentering of the camera module and degrading the optical characteristics of the camera module.

[0188] The first lens 111, the second lens 113, and the third lens 115 may have a predetermined range of sizes. More specifically, the first lens 111, the second lens 113, and the third lens 115 may have a predetermined range of lens diameters. Here, the lens diameters of the first lens 111, the second lens 113, and the third lens 115 may be defined as diameters including the effective and ineffective areas of each lens, as described above. That is, the diameter of the first lens 111 may be defined as the sum of the diameter of the first effective area and the diameter of the first flange portion 111A, the diameter of the second lens 113 may be defined as the sum of the diameter of the second effective area and the diameter of the second flange portion 113A, and the diameter of the third lens 115 may be defined as the sum of the diameter of the third effective area and the diameter of the third flange portion 113A.

[0189] The diameters of the first lens 111, the second lens 113, and the third lens 115 vary depending on the linear expansion coefficient of the lens barrel 500. More specifically, the diameters of the first lens 111, the second lens 113, and the third lens 115 vary depending on the linear expansion coefficients of the lens barrel 500, the first lens 111, the second lens 113, and the third lens 115. That is, the size of the gap between the lenses and the barrel varies depending on the difference in the amount of contraction and expansion between the lenses 111, 113, and 115 and the lens barrel 500, depending on the linear expansion coefficients of the lens barrel 500, the first lens 111, the second lens 113, and the third lens 115.

[0190] The size of the gap between the first lens 111, the second lens 113, and the third lens 115 changes depending on the linear expansion coefficients of the lens barrel 500, the first lens 111, the second lens 113, and the third lens 115. This changes the size of the decenter, which is defined as the deviation between the center and the optical axis of the first lens 111, the second lens 113, and the third lens 115. In this case, the size of the gap between the lenses 111, 113, and 115 and the lens barrel 500 is limited to a set range to realize optical characteristics or to prevent deterioration of optical characteristics due to lens decentering.

[0191] The diameters of the lenses 111, 113, and 115 are limited to a set range in consideration of the size of the gaps between the lenses 111, 113, and 115 and the lens barrel 500. For example, the size of the gaps between the lenses 111, 113, and 115 and the lens barrel 500 is defined as a distance at which optical characteristics can be realized when the first lens 111, the second lens 113, and the third lens 115 are spaced apart from each other within the barrel. For example, the size of the gaps between the lenses 111, 113, and 115 and the lens barrel 500 may be 40 μm or less. If the size of the gaps between the lenses 111, 113, and 115 and the lens barrel 500 exceeds 40 μm, the lens fixing force in the camera module 1000 decreases due to an increase in the gaps between the lenses 111, 113, and 115, and therefore the optical characteristics of the camera module 1000 deteriorate. That is, the maximum distance between the lenses 111, 113, and 115 and the lens barrel 500 to realize the optical characteristics of the camera module is 40 μm.

[0192] Considering the size of the gap between the lenses 111, 113, and 115 and the lens barrel 500, the maximum diameter of the lenses 111, 113, and 115 can be defined by the following Equation 3.

[0193] [Formula 3] Maximum lens diameter = {40 μm / (barrel linear expansion coefficient (ppm / ℃) - lens linear expansion coefficient (ppm / ℃)) × temperature change (℃)}

[0194] Equation 3 is defined by the following Equations 3-1 and 3-2. That is, the distance between the lenses 111, 113, and 115 and the lens barrel 500 can be defined by the following Equation 1-1.

[0195] [Formula 3-1] Spacing (μm) = {(Barrel linear expansion coefficient (ppm / ℃) × Barrel inner diameter (mm) × Temperature change (℃)) - (Lens linear expansion coefficient (ppm / ℃) × Lens diameter (mm) × Temperature change (℃))}

[0196] Equation 3-1 is based on the assumption that the barrel inner diameter and the lens diameter are the same from the first temperature, and the size of the gap is defined by Equation 3-2.

[0197] [Formula 3-2] Spacing (μm) = {(Barrel linear expansion coefficient (ppm / ℃) - Lens linear expansion coefficient (ppm / ℃)) × Lens inner diameter (Barrel inner diameter) (mm) × Temperature change (℃)}

[0198] The lenses 111, 113, and 115 may have diameters equal to or greater than a set size in consideration of optical performance and mechanical processing. Specifically, the first lens 111, the second lens 113, and the third lens 115 may have diameters equal to or greater than 2 mm. That is, the minimum diameters of the first lens 111, the second lens 113, and the third lens 115 may be 2 mm. That is, when the linear expansion coefficients of the lenses 111, 113, and 115, the linear expansion coefficient of the lens barrel 500, and the minimum diameters of the lenses 111, 113, and 115 are taken into consideration, the diameters of the first lens 111, the second lens 113, and the third lens 115 are defined by the following Equations 4 to 6:

[0199] [Formula 4] 2 mm ≦ First lens diameter ≦ {40 μm / (Barrel linear expansion coefficient (ppm / ℃) - Lens linear expansion coefficient (ppm / ℃)) × Temperature change (℃)}

[0200] In Equation 4, the value of {40 μm / (barrel linear expansion coefficient (ppm / ° C.)−lens linear expansion coefficient (ppm / ° C.))×temperature change (° C.)} is 2 mm or more.

[0201] [Formula 5] 2 mm ≦ Second lens diameter ≦ {40 μm / (Barrel linear expansion coefficient (ppm / ℃) - Lens linear expansion coefficient (ppm / ℃)) × Temperature change (℃)}

[0202] In Equation 5, the value of {40 μm / (barrel linear expansion coefficient (ppm / ° C.)−lens linear expansion coefficient (ppm / ° C.))×temperature change (° C.)} is 2 mm or more.

[0203] [Formula 6] 2 mm ≦ Third lens diameter ≦ {40 μm / (Barrel linear expansion coefficient (ppm / ℃) - Lens linear expansion coefficient (ppm / ℃)) × Temperature change (℃)}

[0204] In Equation 6, the value of {40 μm / (barrel linear expansion coefficient (ppm / ° C.)−lens linear expansion coefficient (ppm / ° C.))×temperature change (° C.)} is 2 mm or more.

[0205] When the first lens 111 expands due to a change from a first temperature to a second temperature, the first lens 111 may have a diameter that satisfies Equation 4. More specifically, the first lens 111 may have a diameter within a set range according to Equation 2.

[0206] For example, when the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 0 ppm / °C to 80 ppm / °C, the diameter of the first lens 111 may be 2 mm to 250 mm. When the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 0 ppm / °C to 10 ppm / °C, the diameter of the first lens 111 may be 2 mm to 186 mm. When the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 10 ppm / °C to 20 ppm / °C, the diameter of the first lens 111 may be 2 mm to 250 mm.

[0207] Preferably, when the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 20 ppm / °C to 30 ppm / °C, the diameter of the first lens 111 may be 2 mm to 42 mm. When the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 30 ppm / °C to 40 ppm / °C, the diameter of the first lens 111 may be 2 mm to 23 mm. When the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 40 ppm / °C to 50 ppm / °C, the diameter of the first lens 111 may be 2 mm to 16 mm.

[0208] Preferably, when the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 50 ppm / °C to 60 ppm / °C, the diameter of the first lens 111 may be 2 mm to 13 mm. When the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 60 ppm / °C to 70 ppm / °C, the diameter of the first lens 111 may be 2 mm to 10 mm. When the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 70 ppm / °C to 80 ppm / °C, the diameter of the first lens 111 may be 2 mm to 9 mm.

[0209] When the second lens 113 and the third lens 115 contract as the temperature changes from the first temperature to the third temperature, they may have lens diameters that satisfy Equations 5 and 6. For example, when the linear expansion coefficients of the second lens 113 and the third lens 115 are 55 ppm / °C to 80 ppm / °C, respectively, and the linear expansion coefficient of the lens barrel 500 is greater than 0 ppm / °C to 80 ppm / °C, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 620 mm, respectively.

[0210] Preferably, when the linear expansion coefficients of the second lens 113 and the third lens 115 are 55 ppm / °C to 80 ppm / °C, respectively, and the linear expansion coefficient of the lens barrel 500 is greater than 0 ppm / °C to 10 ppm / °C, respectively, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 14 mm. When the linear expansion coefficients of the second lens 113 and the third lens 115 are 55 ppm / °C to 80 ppm / °C, respectively, and the linear expansion coefficient of the lens barrel 500 is greater than 10 ppm / °C to 20 ppm / °C, respectively, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 18 mm.

[0211] Preferably, when the linear expansion coefficients of the second lens 113 and the third lens 115 are 55 ppm / °C to 80 ppm / °C, respectively, and the linear expansion coefficient of the lens barrel 500 is greater than 20 ppm / °C to 30 ppm / °C, respectively, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 25 mm. When the linear expansion coefficients of the second lens 113 and the third lens 115 are 55 ppm / °C to 80 ppm / °C, respectively, and the linear expansion coefficient of the lens barrel 500 is greater than 30 ppm / °C to 40 ppm / °C, respectively, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 41 mm.

[0212] Preferably, when the linear expansion coefficients of the second lens 113 and the third lens 115 are 55 ppm / °C to 80 ppm / °C, respectively, and the linear expansion coefficient of the lens barrel 500 is greater than 40 ppm / °C to 50 ppm / °C, respectively, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 124 mm. When the linear expansion coefficients of the second lens 113 and the third lens 115 are 55 ppm / °C to 80 ppm / °C, respectively, and the linear expansion coefficient of the lens barrel 500 is greater than 50 ppm / °C to 60 ppm / °C, respectively, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 620 mm.

[0213] Preferably, when the linear expansion coefficients of the second lens 113 and the third lens 115 are 55 ppm / °C to 80 ppm / °C, respectively, and the linear expansion coefficient of the lens barrel 500 is greater than 60 ppm / °C to 70 ppm / °C, respectively, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 41 mm. When the linear expansion coefficients of the second lens 113 and the third lens 115 are 55 ppm / °C to 80 ppm / °C, respectively, and the linear expansion coefficient of the lens barrel 500 is greater than 70 ppm / °C to 80 ppm / °C, respectively, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 124 mm.

[0214] When the temperature changes from the first temperature to the second temperature or the third temperature, the first lens 111, the second lens 113, and the third lens 115 may have diameters within a range set in consideration of the linear expansion coefficients of the lens barrel 500, the first lens 111, the second lens 113, and the third lens 115, and the intervals between the first lens 111, the second lens 113, and the third lens 115 and the lens barrel 500. Therefore, the camera module including the first lens 111, the second lens 113, and the third lens 115 can have improved optical characteristics by controlling the intervals between the lenses and the barrels in response to temperature changes and controlling the size of the decentering of the lenses.

[0215] The diameters of the lenses 111, 113, and 115 are limited to a range set in consideration of the decentering magnitudes of the first lens 111, the second lens 113, and the third lens 115. The maximum diameters of the lenses 111, 113, and 115 in consideration of the decentering magnitudes of the first lens 111, the second lens 113, and the third lens 115 can be defined by the following Equations 7 to 10.

[0216] [Formula 7] Maximum lens diameter = {Lens decenter size (μm) / (Barrel linear expansion coefficient (ppm / ℃) - Lens linear expansion coefficient (ppm / ℃)) × Temperature change (℃)}

[0217] Here, when the linear expansion coefficients of the lenses 111, 113, and 115 are taken into consideration, taking into account the decentering sizes of the lenses 111, 113, and 115, the linear expansion coefficient of the lens barrel 500, and the minimum diameters of the lenses 111, 113, and 115, the diameters of the first lens 111, the second lens 113, and the third lens 115 can be defined by the following Equations 8 to 10.

[0218] [Formula 8] 2 mm≦first lens diameter≦{size of decenter of first lens (μm) / (barrel linear expansion coefficient (ppm / ℃) - lens linear expansion coefficient (ppm / ℃)) × temperature change (℃)}

[0219] In Equation 8, the value of {size of decenter of first lens (μm) / (barrel linear expansion coefficient (ppm / °C)-lens linear expansion coefficient (ppm / °C))×temperature change (°C)} is 2 mm or more.

[0220] [Formula 9] 2 mm ≦ diameter of second lens ≦ {size of decenter of second lens (μm) / (barrel linear expansion coefficient (ppm / ℃) - lens linear expansion coefficient (ppm / ℃)) × temperature change (℃)}

[0221] In Equation 9, the value of {size of decenter of second lens (μm) / (barrel linear expansion coefficient (ppm / °C)-lens linear expansion coefficient (ppm / °C))×temperature change (°C)} is 2 mm or more.

[0222] [Formula 10] 2 mm≦Third lens diameter≦{Depth of third lens decenter (μm) / (Barrel linear expansion coefficient (ppm / ℃) - Lens linear expansion coefficient (ppm / ℃)) × Temperature change (℃)}

[0223] In Equation 10, the value of {the decenter size of the third lens (μm) / (barrel linear expansion coefficient (ppm / °C)-lens linear expansion coefficient (ppm / °C))×temperature change (°C)} is 2 mm or more.

[0224] In Equations 8 to 10, the first lens 111 may have a diameter that satisfies Equation 8 when it expands due to a change from a first temperature to a second temperature. The allowable decentering size of the first lens 111 is 15 μm or less. That is, the decentering size of the first lens 111 for implementing the optical characteristics of the camera module 1000 is 15 μm or less. Thus, according to Equation 8, the first lens 111 may have a diameter within a range set in consideration of the decentering size of the first lens 111.

[0225] For example, when the decenter size of the first lens 111 is 15 μm, the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C, and the linear expansion coefficient of the lens barrel 500 is greater than 0 ppm / °C to 80 ppm / °C, the diameter of the first lens 111 may be 2 mm to 75 mm. Preferably, when the decenter size of the first lens 111 is 15 μm, the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C, and the linear expansion coefficient of the lens barrel 500 is greater than 0 ppm / °C to 10 ppm / °C, the diameter of the first lens 111 may be 2 mm to 70 mm.

[0226] Preferably, the decenter size of the first lens 111 is 15 μm, and when the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 10 ppm / °C to 20 ppm / °C, the diameter of the first lens 111 may be 2 mm to 75 mm. Preferably, the decenter size of the first lens 111 is 15 μm, and when the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 20 ppm / °C to 30 ppm / °C, the diameter of the first lens 111 may be 2 mm to 15 mm.

[0227] Preferably, the decenter size of the first lens 111 is 15 μm, and when the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 30 ppm / °C to 40 ppm / °C, the diameter of the first lens 111 may be 2 mm to 9 mm. Preferably, the decenter size of the first lens 111 is 15 μm, and when the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 40 ppm / °C to 50 ppm / °C, the diameter of the first lens 111 may be 2 mm to 6 mm.

[0228] Preferably, the decenter size of the first lens 111 is 15 μm, and when the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 50 ppm / °C to 60 ppm / °C, the diameter of the first lens 111 may be 2 mm to 5 mm. Preferably, the decenter size of the first lens 111 is 15 μm, and when the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C and the linear expansion coefficient of the lens barrel 500 is greater than 60 ppm / °C to 70 ppm / °C, the diameter of the first lens 111 may be 2 mm to 4 mm.

[0229] Preferably, the decenter size of the first lens 111 is 15 μm, the linear expansion coefficient of the first lens 111 is 3 ppm / °C to 18 ppm / °C, and when the linear expansion coefficient of the lens barrel 500 is more than 70 ppm / °C to 80 ppm / °C, the diameter of the first lens 111 may be 2 mm to 3 mm.

[0230] The second lens 113 and the third lens 115 may have lens diameters that satisfy Equations 9 and 10, respectively, when they shrink due to a change from the first temperature to the third temperature. The allowable decentering size of the second lens 113 and the third lens 115 is 6 μm or less. That is, the decentering size of the second lens 113 and the third lens 115 to implement the optical characteristics of the camera module 1000 is 6 μm or less.

[0231] For example, when the decenter size of the second lens 113 and the third lens 115 is 6 μm, the linear expansion coefficients of the second lens 113 and the third lens 115 are 3 ppm / °C to 18 ppm / °C, respectively, and the linear expansion coefficient of the lens barrel 500 is greater than 0 ppm / °C to 80 ppm / °C, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 95 mm, respectively.

[0232] Preferably, the decenter size of the second lens 113 and the third lens 115 is 6 μm, the linear expansion coefficients of the second lens 113 and the third lens 115 are 3 ppm / °C to 18 ppm / °C, respectively, and when the linear expansion coefficient of the lens barrel 500 is greater than 0 ppm / °C to 10 ppm / °C, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 2.2 mm. Preferably, the decenter size of the second lens 113 and the third lens 115 is 6 μm, the linear expansion coefficients of the second lens 113 and the third lens 115 are 3 ppm / °C to 18 ppm / °C, respectively, and when the linear expansion coefficient of the lens barrel 500 is greater than 10 ppm / °C to 20 ppm / °C, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 3 mm.

[0233] Preferably, the decenter size of the second lens 113 and the third lens 115 is 6 μm, the linear expansion coefficients of the second lens 113 and the third lens 115 are 3 ppm / °C to 18 ppm / °C, respectively, and when the linear expansion coefficient of the lens barrel 500 is greater than 20 ppm / °C to 30 ppm / °C, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 4 mm. Preferably, the decenter size of the second lens 113 and the third lens 115 is 6 μm, the linear expansion coefficients of the second lens 113 and the third lens 115 are 3 ppm / °C to 18 ppm / °C, respectively, and when the linear expansion coefficient of the lens barrel 500 is greater than 30 ppm / °C to 40 ppm / °C, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 7 mm, respectively. Preferably, the decenter size of the second lens 113 and the third lens 115 is 6 μm, the linear expansion coefficients of the second lens 113 and the third lens 115 are 3 ppm / °C to 18 ppm / °C, respectively, and when the linear expansion coefficient of the lens barrel 500 is greater than 40 ppm / °C to 50 ppm / °C, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 19 mm, respectively.

[0234] Preferably, the decenter size of the second lens 113 and the third lens 115 is 6 μm, the linear expansion coefficients of the second lens 113 and the third lens 115 are 3 ppm / °C to 18 ppm / °C, respectively, and when the linear expansion coefficient of the lens barrel 500 is more than 50 ppm / °C to 60 ppm / °C, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 95 mm, respectively.

[0235] Preferably, the decenter size of the second lens 113 and the third lens 115 is 6 μm, the linear expansion coefficients of the second lens 113 and the third lens 115 are 3 ppm / °C to 18 ppm / °C, respectively, and when the linear expansion coefficient of the lens barrel 500 is greater than 60 ppm / °C to 70 ppm / °C, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 7 mm. Preferably, the decenter size of the second lens 113 and the third lens 115 is 6 μm, the linear expansion coefficients of the second lens 113 and the third lens 115 are 3 ppm / °C to 18 ppm / °C, respectively, and when the linear expansion coefficient of the lens barrel 500 is greater than 70 ppm / °C to 80 ppm / °C, the diameters of the second lens 113 and the third lens 115 may be 2 mm to 19 mm, respectively.

[0236] When the temperature changes from the first temperature to the second temperature or the third temperature, the first lens 111, the second lens 113, and the third lens 115 may have diameters within a range set in consideration of the linear expansion coefficients of the lens barrel 500, the first lens 111, the second lens 113, and the third lens 115, and decentering values ​​of the first lens 111, the second lens 113, and the third lens 115. Therefore, the camera module including the first lens 111, the second lens 113, and the third lens 115 may have improved optical characteristics by controlling the size of the gap between the lens and the barrel and the size of the decentering of the lens in response to temperature changes.

[0237] The heat dissipation members of the camera modules according to the third embodiment and the comparative example and the thermal characteristics of the heat dissipation members will be described in more detail below. These embodiments are merely presented as examples to explain the present invention in more detail. Therefore, the present invention is not limited to these embodiments.

[0238] [Example 1] A first lens, a second lens, and a third lens were disposed inside the barrel. A spacing adjustment member was disposed between the first lens, the second lens, and the third lens to maintain the spacing between the lenses. The camera module was then heated from a first temperature of 25° C. to a second temperature of 105° C. and a third temperature of −40° C., and the diameters of the first lens, the second lens, and the third lens were measured using Equations 4 to 6 at various ranges of the linear expansion coefficient of the barrel.

[0239] [Example 2] A first lens, a second lens, and a third lens were disposed inside the barrel. A spacing adjustment member was disposed between the first lens, the second lens, and the third lens to maintain the spacing between the lenses. The camera module was then heated to a first temperature of 25°C, a second temperature of 105°C, and a third temperature of -40°C, and the diameters of the first lens, the second lens, and the third lens were measured at various ranges of the linear expansion coefficient of the barrel according to Equations 8 to 10. The decentering dimension of the first lens was 15 μm, and the decentering dimensions of the second lens and the third lens were 6 μm.

[0240] FIG. 18 is a table showing the diameters of the first to third lenses according to Example 1 of the third embodiment, and FIG. 19 is a table showing the diameters of the first to third lenses according to Example 2 of the third embodiment.

[0241] In FIGS. 18 and 19, data having negative values ​​and data having values ​​less than 2 mm are merely result values ​​calculated by mathematical formulas and do not actually represent the diameters of the first to third lenses.

[0242] Referring to FIG. 18, the lens according to Example 1 has a diameter range as shown in FIG. 18 when the gaps between the first, second, and third lenses and the barrel are 40 μm. Referring to FIG. 19, the lens according to Example 2 has a diameter range as shown in FIG. 19 when the decentering of the first lens is 15 μm and the decenters of the second and third lenses are 6 μm. The camera module according to the third embodiment can control the lens diameter within a set range by taking into account the range of gaps between the lens and the barrel and / or the decentering of the lens when the temperature changes from room temperature to high temperature or from room temperature to low temperature. Therefore, the camera module according to the third embodiment can prevent deterioration of the optical performance of the lens due to temperature changes, thereby achieving improved optical characteristics.

[0243] FIG. 20 is an example of a plan view of a vehicle to which a camera module according to an embodiment of the invention is applied. Referring to FIG. 20, the vehicle camera system according to the embodiment of the invention includes an image generating unit 11, a first information generating unit 12, second information generating units 21, 22, 23, and 24, and a control unit 14. The image generating unit 11 may include at least one camera module 20 disposed in the vehicle and may capture images of the area in front of the vehicle and / or the driver to generate images of the area in front of the vehicle and / or the interior of the vehicle. The image generating unit 11 may generate images of the area around the vehicle or the driver in one or more directions, as well as images of the area in front of the vehicle, using the camera module 20. The front image and the surrounding image may be digital images and may include color images, black-and-white images, infrared images, etc. The front image and the surrounding image may include still images and video images. The image generating unit 11 provides the driver image, the front image, and the surrounding image to the control unit 14. The first information generator 12 may include at least one radar and / or camera disposed in the host vehicle, and generates first sensing information by sensing the area ahead of the host vehicle. Specifically, the first information generator 12 is disposed in the host vehicle and senses the position and speed of a vehicle ahead of the host vehicle, the presence and position of a pedestrian, etc., to generate the first sensing information.

[0244] The first information generator 12 can use the first sensing information to control the distance between the host vehicle and a vehicle ahead to maintain a constant distance, thereby improving the stability of vehicle operation in specific, pre-set cases, such as when the driver changes lanes or when reversing into parking. The first information generator 12 provides the first sensing information to the controller 14. The second information generators 21, 22, 23, and 24 sense each side of the host vehicle based on the forward image generated by the image generator 11 and the first sensing information generated by the first information generator 12, and generate second sensing information. Specifically, the second information generators 21, 22, 23, and 24 may include at least one radar and / or camera disposed on the host vehicle, and may sense the position and speed of vehicles positioned on the sides of the host vehicle and capture images. Here, the second information generators 21, 22, 23, and 24 may be disposed on both the front and rear sides of the host vehicle, respectively. Such a vehicle camera system may include the following camera modules, and may provide or process information acquired from the front, rear, side, or corner areas of the vehicle to the user to protect the vehicle and objects from autonomous driving or surrounding safety.

[0245] A plurality of optical systems of camera modules according to embodiments of the present invention may be installed in a vehicle to comply with safety regulations, enhance autonomous driving functions, and increase convenience. Furthermore, optical systems of camera modules are applied in vehicles as components for controlling systems such as lane keeping assistance systems (LKAS), lane departure warning systems (LDWS), and driver monitoring systems (DMS). Such vehicle camera modules can achieve stable optical performance even when the ambient temperature changes, and can provide cost-competitive modules to ensure the reliability of vehicle components.

[0246] In an embodiment of the invention, a spacer having a buffer structure is applied to the outside of at least one lens in a vehicle camera module to withstand temperature changes from temperatures below -20°C to temperatures above 70°C, for example, a range of -40°C to 105°C. This provides longitudinal relaxation for lenses with high thermal expansion coefficients, providing elasticity to contract or expand in response to the expansion of lenses made of plastic or glass, thereby suppressing the amount of change in the optical axis direction of the lens's effective diameter region. This reduces changes in the optical characteristics of camera modules using lenses made of plastic or glass. Additionally, a buffer structure can be further included in the outer flange of the lens to suppress elastic deformation of the lens itself.

[0247] The features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment may be combined or modified with other embodiments by a person skilled in the art to which the embodiment belongs. Therefore, such combinations and modifications should be construed as falling within the scope of the present invention. While the above description focuses on the embodiments, these are merely examples and do not limit the present invention. A person skilled in the art to which the present invention belongs may make various modifications and applications not exemplified above within the scope of the present embodiments, provided that such modifications and applications do not deviate from the essential characteristics of the present embodiments. For example, each component specifically presented in the embodiments may be modified. Such modifications and variations should be construed as falling within the scope of the present invention, as defined by the appended claims.

Claims

1. a lens barrel having a through hole therein; a lens unit including a first lens, a second lens, and a third lens, the first lens, the second lens, and the third lens being disposed in the through-hole of the lens barrel and having optical axes aligned from an object side to a sensor side; An image sensor and Including, the second lens and the first lens are made of different materials, The refractive index of the second lens is lower than the refractive index of the first lens, the first lens, the second lens, and the third lens each include a first flange portion, a second flange portion, and a third flange portion extending from the optical axis toward an inner wall of the lens barrel, the lens barrel includes a first support portion disposed on an outer side of the first flange portion, a second support portion disposed on an outer side of the second flange portion, and a third support portion disposed on an outer side of the third flange portion, an outer diameter of the lens barrel at a position where an upper portion of the first flange portion contacts the lens barrel is a first outer diameter; an outer diameter of the lens barrel at a position where an upper portion of the second flange portion contacts the lens barrel is a second outer diameter; an outer diameter of the lens barrel at a position where an upper portion of the third flange portion contacts the lens barrel is a third outer diameter; an outer diameter of the lens barrel at a position where the upper portion of the image sensor contacts the lens barrel is a fourth outer diameter; the third outer diameter is smaller than the fourth outer diameter and larger than the second outer diameter; the first lens on the optical axis includes a first object-side surface and a second sensor-side surface; a third surface on the object side and a fourth surface on the sensor side of the second lens have different radii of curvature on the optical axis; a center of a first contact surface where the second flange portion of the second lens comes into contact with the inner surface of the second support portion is located closer to the third surface or the fourth surface having a larger radius of curvature, based on the center of a thickness of the second flange portion.

2. the first outer diameter is smaller than the third outer diameter; the first lens is made of glass; The camera module of claim 1 , wherein the second lens is made of a plastic material.

3. an optical filter disposed inside a lower end of the lens barrel and between the third lens and an image sensor; The camera module of claim 1 , wherein the third lens is made of a plastic material.

4. The camera module according to claim 1 , wherein a thickness of the first support portion is a minimum distance between an inner surface and an outer surface of the first support portion, and is the same as a thickness of the second support portion.

5. The camera module of claim 3 , wherein a thickness of the second support portion is a minimum distance between an inner surface and an outer surface of the second support portion and is the same as a thickness of the third support portion.

6. a lens barrel having a through hole therein; a first lens, a second lens, and a third lens disposed in the through-hole of the lens barrel, the first lens, the second lens, and the third lens having optical axes aligned from an object side to a sensor side; Including, the second lens and the first lens are made of different materials, The refractive index of the second lens is lower than the refractive index of the first lens, the first lens, the second lens, and the third lens each include a first flange portion, a second flange portion, and a third flange portion extending from the optical axis toward an inner surface of the lens barrel, the lens barrel includes a first support portion disposed outside the first flange portion, a second support portion disposed outside the second flange portion, and a third support portion disposed outside the third flange portion, the first, second, and third support parts include sections at the outside of the first, second, and third lenses where an inner wall and an outer surface of the lens barrel are perpendicular to each other; an outer surface of the first support portion has a first depth, an outer surface of the second support portion has a second depth, and an outer surface of the third support portion has a third depth, based on a virtual straight line on an outer surface of a lower end of the lens barrel that is parallel to the optical axis; the second depth is greater than the first depth and less than the third depth; the first lens on the optical axis includes a first object-side surface and a second sensor-side surface; a third surface on the object side and a fourth surface on the sensor side of the second lens have different radii of curvature on the optical axis; a center of a first contact surface where the second flange portion of the second lens comes into contact with the inner surface of the second support portion is located closer to the third surface or the fourth surface having a larger radius of curvature, based on the center of a thickness of the second flange portion.

7. an optical filter disposed inside a lower end of the lens barrel and between the third lens and an image sensor; the first and second surfaces of the first lens are spherical; The camera module according to claim 6 , wherein a fifth object-side surface and a sixth sensor-side surface of the third lens are aspherical.

8. The camera module according to claim 6 or 7, wherein a thickness of the first support portion is a minimum distance between an inner surface and an outer surface of the first support portion, and is the same as a thickness of the second support portion.

9. The camera module of claim 8 , wherein a thickness of the second support portion is a minimum distance between an inner surface and an outer surface of the second support portion and is the same as a thickness of the third support portion.

10. 10. The camera module of claim 1, further comprising: a first inclined portion extending from the first support portion toward the second support portion and inclined toward the third support portion; and a second inclined portion extending from the second support portion and inclined toward the third support portion.

11. an inner surface of the second support portion contacts an outer surface of the second flange portion; 7. The camera module of claim 1, wherein the length of a first contact surface where the second flange portion of the second lens contacts the inner surface of the second support portion is 20% to 50% of the thickness of the second flange portion.

12. The camera module according to claim 11 , wherein a center of the first contact surface is located closer to an object side than a center of the second flange portion of the second lens.

13. The camera module according to claim 11 , wherein the difference between the radii of curvature of the third surface and the fourth surface is 1 mm or more.

14. the radius of curvature of the third surface is larger than the radius of curvature of the fourth surface; The camera module according to claim 13 , wherein a center of the first contact surface is located closer to an object side than a center of a second flange portion of the second lens.

15. The camera module of claim 14 , wherein the diameter of the first lens is smaller than the diameter of the second lens.

16. The refractive index of the third lens is lower than the refractive index of the first lens; the third flange portion of the third lens includes a second contact surface that contacts an inner surface of a third support portion of the lens barrel; 10. The camera module according to claim 1, wherein the length of the second contact surface is 20% to 50% of the thickness of the third flange portion.

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