Imaging lens system and camera module

Abstract

The present disclosure relates to an imaging lens system including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in order from an object side. The seventh lens has a convex image side surface, the eighth lens has a positive refractive power, and the imaging lens system satisfies the following conditional expressions: 1.10 lt; f3 / flt; f is the focal length of the imaging lens system, and f3 is the focal length of the third lens. The present disclosure also relates to a camera module comprising the imaging lens system.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0146727, filed October 30, 2023, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety for all purposes. TECHNICAL FIELD

[0003] The disclosure relates to an imaging lens system capable of achieving constant optical performance regardless of temperature changes in the surrounding environment. BACKGROUND

[0004] A small monitoring camera can be configured to capture image information within a monitoring area. For example, a small monitoring camera can be installed on a front bumper, a rear bumper, or the like of a vehicle, and can provide a captured image to a driver.

[0005] Early small monitoring cameras were designed to capture images of obstacles adjacent to a vehicle, and thus not only had a relatively low resolution but also a large resolution variation range as the temperature changed from -40 to 80℃. However, as the requirements for autonomous driving functions of vehicles are increasing, there can be a need to develop a monitoring camera having a high resolution and constant optical characteristics even under severe temperature conditions.

[0006] The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure. SUMMARY

[0007] The purpose of the summary is to summarize, in a simple fashion, the disclosure content of the application. The summary is not intended to identify key or essential features of the claimed subject matter, nor is it meant to be used in determining the scope of the claimed subject matter.

[0008] In one general aspect, an imaging lens system includes, arranged in order from an object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. The seventh lens has a convex image side surface, the eighth lens has positive refractive power, and the imaging lens system satisfies the following conditional expression: 1.10 < f3 / f < 1.40, where f is a focal length of the imaging lens system, and f3 is a focal length of the third lens.

[0009] The first lens can have a concave image side surface.

[0010] The second lens can have a convex image side surface.

[0011] The third lens can have a convex image side surface.

[0012] The fourth lens can have a concave image side surface.

[0013] The fifth lens can have a convex image side surface.

[0014] The sixth lens can have a concave image side surface.

[0015] The camera module can include a housing, a lens barrel disposed in the housing and accommodating the imaging lens system, and an image sensor disposed in the housing at an imaging surface of the imaging lens system.

[0016] A coupling point of the lens barrel and the housing can be closer to the object side than an image side surface of the eighth lens, and the camera module can satisfy one or more of the following conditional expressions: 0.60 < BFL / CP < 0.82, and 0.80 < f3 / CP < 1.0, where CP is the coupling point of the lens barrel and the housing, and BFL is a distance from the image side surface of the eighth lens to the imaging surface.

[0017] In another general aspect, an imaging lens system includes, arranged in order from an object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens, wherein the imaging lens system satisfies the following conditional expression: 1.0 < (L1DTn+L4DTn) / (L5DTn+L8DTn) < 1.4, where L1DTn is a rate of change of refractive index as a function of temperature of the first lens, L4DTn is a rate of change of refractive index as a function of temperature of the fourth lens, L5DTn is a rate of change of refractive index as a function of temperature of the fifth lens, and L8DTn is a rate of change of refractive index as a function of temperature of the eighth lens.

[0018] The seventh lens can have a convex image side surface.

[0019] The imaging lens system can satisfy the following conditional expression: 4.0 (10 -6 / °C) < |L3DTn| < 8.0 (10 -6 / °C), where L3DTn is a rate of change of refractive index as a function of temperature of the third lens.

[0020] The camera module can include a housing, a lens barrel disposed in the housing and accommodating the imaging lens system, and an image sensor disposed in the housing at an imaging surface of the imaging lens system, wherein the lens barrel can have a first coefficient of thermal expansion, and the housing can have a second coefficient of thermal expansion different from the first coefficient of thermal expansion.

[0021] In another general aspect, an imaging lens system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in order from an object side, wherein the seventh lens has a convex image-side surface, wherein the eighth lens has positive refractive power, and wherein the imaging lens system satisfies the following conditional expression: 4.0 (10 -6 / °C) < |L3DTn| < 8.0 (10 -6 / °C), where L3DTn is the refractive index changing rate of the third lens according to temperature change.

[0022] Other features and aspects will be apparent from the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a configuration diagram of an imaging lens system according to a first embodiment of the present disclosure.

[0024] Figure 2 yes Figure 1 Aberration curves of the imaging lens system shown in .

[0025] Figure 3 yes Figure 1 MTF curve of the imaging lens system shown in .

[0026] Figure 4 It shows Figure 1 FIG. 1 is a graph showing the back focal length (BFL) of the imaging lens system as a function of temperature.

[0027] Figure 5 is a configuration diagram of an imaging lens system according to a second embodiment of the present disclosure.

[0028] Figure 6 yes Figure 5 Aberration curves of the imaging lens system shown in .

[0029] Figure 7 yes Figure 5 MTF curve of the imaging lens system shown in .

[0030] Figure 8 It shows Figure 5 Graph of BFL according to temperature change of the imaging lens system shown in FIG.

[0031] Figure 9 is a configuration diagram of an imaging lens system according to a third embodiment of the present disclosure.

[0032] Figure 10 yes Figure 9 Aberration curves of the imaging lens system shown in .

[0033] Figure 11 is Figure 9 aberration curves of the imaging lens system shown in FIG. 12.

[0034] Figure 12 is a graph showing Figure 9 aberration curves of the imaging lens system shown in FIG. 12.

[0035] Figure 13 is a configuration diagram of an imaging lens system according to a fourth embodiment of the present disclosure.

[0036] Figure 14 is Figure 13 aberration curves of the imaging lens system shown in FIG. 12.

[0037] Figure 15 is Figure 13 aberration curves of the imaging lens system shown in FIG. 12.

[0038] Figure 16 is a graph showing Figure 13 aberration curves of the imaging lens system shown in FIG. 12.

[0039] Figure 17 is a configuration diagram of an imaging lens system according to a fifth embodiment of the present disclosure.

[0040] Figure 18 is Figure 17 aberration curves of the imaging lens system shown in FIG. 12.

[0041] Figure 19 is Figure 17 aberration curves of the imaging lens system shown in FIG. 12.

[0042] Figure 20 is a graph showing Figure 17 aberration curves of the imaging lens system shown in FIG. 12.

[0043] Figure 21 is a configuration diagram of an imaging lens system according to a sixth embodiment of the present disclosure.

[0044] Figure 22 is Figure 21 aberration curves of the imaging lens system shown in FIG. 12.

[0045] Figure 23 is Figure 21 aberration curves of the imaging lens system shown in FIG. 12.

[0046] Figure 24 is a graph showing Figure 21 aberration curves of the imaging lens system shown in FIG. 12.

[0047] Figure 25 is a configuration diagram of an imaging lens system according to a seventh embodiment of the present disclosure.

[0048] Figure 26 is an aberration curve of the imaging lens system shown in Figure 25

[0049] Figure 27 is an MTF curve of the imaging lens system shown in Figure 25

[0050] Figure 28 is a curve showing the BFL of the imaging lens system shown in Figure 25

[0051] Figure 29 is a cross-sectional view of a camera module including an imaging lens system according to an embodiment of the present disclosure.

[0052] Throughout the drawings and specific embodiments, the same reference numerals refer to the same elements except where otherwise described. The drawings can not be to scale and the dimensions, proportions, and details of the components can have been exaggerated for the sake of clarity and convenience in the drawings. DETAILED DESCRIPTION

[0053] Hereinafter, while examples of the present disclosure will be described in detail with reference to the accompanying drawings, it should be noted that the examples are not limited thereto.

[0054] The following detailed description is provided to help the reader obtain a thorough understanding of the methods, apparatuses, and / or systems described herein. However, various changes, modifications, and equivalents thereof will become apparent to those skilled in the art after an understanding of the present disclosure. For example, the order of the operations described herein is merely an example, and is not limited to the order set forth herein, except where the order of operations must occur in a specific order, which will be apparent to those skilled in the art after an understanding of the present disclosure. Also, descriptions of features that are well known in the art can be omitted for more clarity and conciseness.

[0055] The features described herein can be implemented in different forms and should not be construed as limited to the examples described herein. Rather, these examples are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the methods, apparatuses, and / or systems described herein to those skilled in the art after an understanding of the present disclosure. The examples described herein are to be considered in a descriptive sense only and not for purposes of limitation.

[0056] ​​​Throughout this specification, where an element such as a layer, region, or substrate is described as being "on" or "connected to" another element, it can be directly on or connected to the other element, or intervening elements can be present. In contrast, where an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. Other embodiments are set forth in the accompanying claims.

[0057] As used herein, the term "and / or" includes any one of the associated listed items, as well as any combination of any two or more of the associated listed items; similarly, the term "at least one of' includes any one of the associated listed items, as well as any combination of any two or more of the associated listed items.

[0058] Although the terms "first," "second," and "third" can be used herein to describe various elements, components, regions, layers, or sections, these elements, components, regions, layers, or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer, or section mentioned in one example can also be called a second element, component, region, layer, or section in another example without departing from the teachings of the examples described herein.

[0059] Spatially relative terms such as "on", "above", "under", "below", and the like can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms can be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "on" other elements or features would then be oriented "below" or "on" the other elements or features. Thus, the term "above" can encompass both an orientation of above and below. The device can be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0060] The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the present disclosure. As used herein, the expressions "a", "an" and "the" are intended to include both singular and plural forms, unless the context clearly indicates otherwise. The expressions "comprises", "comprising", "includes", "including" and "has", "having" as used herein, specify the presence of stated features, numbers, operations, components, elements, and / or a combination thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, components, elements, and / or a combination thereof.

[0061] Due to manufacturing techniques and / or tolerances, variations in the shapes of the structures shown in the drawings can occur. Therefore, the examples described herein are not intended to be limited to the particular shapes of structures shown in the drawings, but include deviations in shapes that occur during manufacturing.

[0062] It should be noted that, in this document, the use of the expression "can", for example with respect to examples that "can include" or "can implement", means that there exists at least one example for which the feature is included or implemented, and that all examples are not limited to this.

[0063] Features of the examples described herein can be combined with each other in a variety of ways, as will be apparent after understanding the disclosure. Also, although the examples described herein have various configurations, other configurations are possible after understanding the disclosure.

[0064] In the present disclosure, the first lens refers to the lens closest to an object (or a subject), and the eighth lens refers to the lens closest to an imaging surface (or an image sensor). In the present disclosure, the units of the radius of curvature, the thickness, the distance from the object side surface of the first lens to the imaging surface (TTL), the height of the imaging surface (IMG HT), and the focal length are expressed in millimeters (mm). Also, the units of the refractive index change rate (DTn) and the thermal expansion coefficient (CTE) described in the present specification can be 10 -6 / °C.

[0065] The thickness of the lens, the gap between the lenses, and the TTL refer to the distance along the optical axis. Also, in the description of the lens shape, the configuration that one surface is convex means that the paraxial region of the surface is convex, and the configuration that one surface is concave means that the paraxial region of the surface is concave.

[0066] Therefore, even when it is described that one surface of the lens is convex, the edge of the lens can be concave. Similarly, even when it is described that one surface of the lens is concave, the edge of the lens can be convex.

[0067] One aspect of the present disclosure can be to solve the above-described problems, and can provide an imaging lens system capable of achieving high resolution by using both plastic lenses and glass lenses, while suppressing the focal point change amplitude due to rapid temperature deviation to 10 micrometers (μm) or less.

[0068] The imaging lens system according to the first aspect of the present disclosure can include a plurality of lenses. For example, the imaging lens system according to the first aspect can include, arranged in order from the object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. The imaging lens system according to the first aspect can include a lens having a convex image side surface. For example, in the imaging lens system according to the first aspect, the seventh lens can have a convex image side surface. The imaging lens system according to the first aspect can include a lens having positive refractive power. For example, in the imaging lens system according to the first aspect, the eighth lens can have positive refractive power. The imaging lens system according to the first aspect can satisfy a certain conditional expression. For example, the imaging lens system according to the first aspect can satisfy the conditional expression 1.10 < f3 / f < 1.40, where f is a focal length of the imaging lens system, and f3 is a focal length of the third lens.

[0069] The imaging lens system according to the second aspect of the present disclosure can include a plurality of lenses. For example, the imaging lens system according to the second aspect can include, arranged in order from the object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. The imaging lens system according to the second aspect can satisfy a certain conditional expression. For example, the imaging lens system according to the second aspect can satisfy the conditional expression 1.0 < (L1DTn+L4DTn) / L5DTn+L8DTn) < 1.4. In this conditional expression, L1DTn is a rate of change of refractive index according to a change in temperature of the first lens, L4DTn is a rate of change of refractive index according to a change in temperature of the fourth lens, L5DTn is a rate of change of refractive index according to a change in temperature of the fifth lens, and L8DTn is a rate of change of refractive index according to a change in temperature of the eighth lens.

[0070] An imaging lens system according to a third aspect of the disclosure can include a plurality of lenses. For example, the imaging lens system according to the third aspect can include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in order from an object side. The imaging lens system according to the third aspect can include a stop. For example, the imaging lens system according to the third aspect can include a stop disposed between the second lens and the third lens. The imaging lens system according to the third aspect can include a lens having a convex image side. For example, in the imaging lens system according to the third aspect, the seventh lens can have a convex image side. The imaging lens system according to the third aspect can include a lens having positive refractive power. For example, in the imaging lens system according to the third aspect, the eighth lens can have positive refractive power. The imaging lens system according to the third aspect can be configured to minimize a focal length change due to a temperature change. For example, the imaging lens system according to the third aspect can satisfy a conditional expression 4.0 < L3DTn < 8.0 (10 -6 / °C), where L3DTn is a refractive index change rate of the third lens according to a temperature change.

[0071] An imaging lens system according to a fourth aspect of the disclosure can include a first lens to an eighth lens arranged in order from an object side, and can satisfy one or more of the following conditional expressions:

[0072] 2.60 < f2 / f < 4.60

[0073] 1.0 < f3 / f < 1.40

[0074] -2.40 < f4 / f < -1.20

[0075] In the conditional expressions, f2 is a focal length of the second lens, and f4 is a focal length of the fourth lens.

[0076] An imaging lens system according to a fifth aspect of the disclosure includes a first lens to an eighth lens arranged in order from an object side, and can satisfy one or more of the following conditional expressions:

[0077] -1.0 < f1 / f3 < -0.6

[0078] 2.40 < f2 / f3 < 4.20

[0079] -2.0 < f4 / f3 < -1.0

[0080] 1.0 < f5 / f3 < 2.0

[0081] -3.0 < f6 / f3 < -2.0

[0082] 1.60 < f7 / f3 < 5.20

[0083] 0.80 < f7 / f8 < 1.20

[0084] 0.30 < f8 / (f3+f5+f7) < 2.0

[0085] -14.0 < (f1+f2) / (f3+f4) < -3.0

[0086] In the conditional expressions, f1 is the focal length of the first lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, and f8 is the focal length of the eighth lens.

[0087] An imaging lens system according to a sixth aspect of the present disclosure includes first through eighth lenses arranged in order from the object side, and can satisfy one or more of the following conditional expressions:

[0088] 0.80 < BFL / IMG HT < 1.40

[0089] 2.0 < (f3+BFL) / f < 2.40

[0090] -3.80 < R7 / R12 < -2.40

[0091] 0.60 < R7 / R14 < 1.20

[0092] -0.80 < R14 / f7 < -0.30

[0093] -1.0 < R14 / f8 < -0.10

[0094] 0.20 < R15 / f8 < 0.80

[0095] In the conditional expressions, BFL is the distance from the image side surface of the last lens (the eighth lens) to the image plane, IMG HT is the height of the image plane, R7 is the radius of curvature of the object side surface of the fourth lens, R12 is the radius of curvature of the image side surface of the sixth lens, and R14 is the radius of curvature of the image side surface of the seventh lens.

[0096] An imaging lens system according to a seventh aspect of the present disclosure includes first through eighth lenses arranged in order from the object side, and can satisfy one or more of the following conditional expressions:

[0097] 4.0 < L3DTn < 8.0

[0098] 0.42 < L1DTn / L3DTn < 1.0

[0099] 1.0 < (L1DTn+L4DTn) / (L5DTn+L8DTn) < 1.40

[0100] 0.92 < (L4DTn+L5DTn) / (L6DTn+L7DTn) < 1.20

[0101] In the conditional expression, L6DTn is a rate of change of a refractive index of the sixth lens according to a change in temperature, and L7DTn is a rate of change of a refractive index of the seventh lens according to a change in temperature.

[0102] The imaging lens system according to the eighth aspect of the disclosure includes two or more of the first aspect through the seventh aspect having the following characteristics. For example, the imaging lens system according to the eighth aspect can include the characteristics of the first aspect, and can satisfy one or more conditional expressions according to the fifth aspect. As another example, the imaging lens system according to the eighth aspect can include the characteristics of the second aspect, and can satisfy one or more conditional expressions according to the sixth aspect or the seventh aspect.

[0103] The imaging lens system according to the first aspect through the eighth aspect can include one or more lenses having the following characteristics as needed. As an example, the imaging lens system according to the first aspect can include one of the first lens through the eighth lens having the following characteristics. As another example, the imaging lens system according to the second aspect can include two or more of the first lens through the eighth lens having the following characteristics. However, the imaging lens system according to the above aspects does not necessarily include a lens having the following characteristics. Hereinafter, the characteristics of the first lens through the eighth lens will be described.

[0104] The first lens can have a refractive power. For example, the first lens can have a negative refractive power. The first lens can have a concave shape on one surface. For example, the first lens can have a concave image side surface. The first lens can include a spherical surface or an aspherical surface. For example, both surfaces of the first lens can be spherical. The first lens can be formed of a material having high light transmittance and excellent processing performance. For example, the first lens can be formed of glass. The first lens can be configured to have characteristics that are advantageous to improve aberration. For example, the first lens can have a refractive index of 1.75 or more and an Abbe number of 45 or more.

[0105] The second lens can have a refractive power. For example, the second lens can have a positive refractive power. The second lens can have a convex shape on one surface. For example, the second lens can have a convex image side surface. The second lens can include an aspheric surface. For example, both surfaces of the second lens can be aspheric. The second lens can be formed of a material having high light transmittance and excellent processing performance. For example, the second lens can be formed of a plastic material. The second lens can have a predetermined refractive index. For example, the refractive index of the second lens can be 1.64 or more. The second lens can have a predetermined Abbe number. For example, the Abbe number of the second lens can be greater than 20 and less than 30.

[0106] The third lens can have a refractive power. For example, the third lens can have a positive refractive power. The third lens can have a convex shape on one surface. For example, the third lens can have a convex image side surface. The third lens can include an aspheric surface. For example, both surfaces of the third lens can be aspheric. The third lens can be formed of a material having high light transmittance and excellent processing performance. For example, the third lens can be formed of glass. The third lens can be configured to have a characteristic that is advantageous for improving aberration. For example, the third lens can have a refractive index of 1.70 or more and an Abbe number of 45 or more.

[0107] The fourth lens can have a refractive power. For example, the fourth lens can have a negative refractive power. The fourth lens can have a concave shape on one surface. For example, the fourth lens can have a concave image side surface. The fourth lens can include an aspheric surface. For example, both surfaces of the fourth lens can be aspheric. The fourth lens can be formed of a material having high light transmittance and excellent processing performance. For example, the fourth lens can be formed of a plastic material. The fourth lens can have a predetermined refractive index. For example, the refractive index of the fourth lens can be 1.6 or more. The fourth lens can have a predetermined Abbe number. For example, the Abbe number of the fourth lens can be greater than 20 and less than 30.

[0108] The fifth lens can have a refractive power. For example, the fifth lens can have a positive refractive power. The fifth lens can have a convex shape on one surface. For example, the fifth lens can have a convex image side surface. The fifth lens can include an aspheric surface. For example, both surfaces of the fifth lens can be aspheric. The fifth lens can be formed of a material having high light transmittance and excellent processing performance. For example, the fifth lens can be formed of a plastic material. The fifth lens can have a predetermined refractive index. For example, the refractive index of the fifth lens can be less than 1.6. The fifth lens can have a predetermined Abbe number. For example, the Abbe number of the fifth lens can be greater than 50 and less than 60.

[0109] The sixth lens can have a refractive power. For example, the sixth lens can have a negative refractive power. The sixth lens can have a concave shape on one surface. For example, the sixth lens can have a concave image side surface. The sixth lens can include an aspheric surface. For example, both surfaces of the sixth lens can be aspheric. The sixth lens can be formed of a material having a high light transmittance and excellent processability. For example, the sixth lens can be formed of a plastic material. The sixth lens can have a predetermined refractive index. For example, the refractive index of the sixth lens can be substantially the same as or similar to that of the fourth lens. The sixth lens can have a predetermined Abbe number. For example, the Abbe number of the sixth lens can be substantially the same as or similar to that of the fourth lens.

[0110] The seventh lens can have a refractive power. For example, the seventh lens can have a positive refractive power. The seventh lens can have a convex shape on one surface. For example, the seventh lens can have a convex image side surface. The seventh lens can include an aspheric surface. For example, both surfaces of the seventh lens can be aspheric. The seventh lens can be formed of a material having a high light transmittance and excellent processability. For example, the seventh lens can be formed of a plastic material. The seventh lens can have a predetermined refractive index. As an example, the refractive index of the seventh lens can be substantially the same as or similar to that of the fifth lens. The seventh lens can have a predetermined Abbe number. For example, the Abbe number of the seventh lens can be substantially the same as or similar to that of the fifth lens.

[0111] The eighth lens can have a refractive power. For example, the eighth lens can have a positive refractive power or a negative refractive power. The eighth lens can have a convex shape on one surface. For example, the eighth lens can have a convex object side surface. The eighth lens can include an aspheric surface. For example, both surfaces of the eighth lens can be aspheric. The eighth lens can be formed of a material having a high light transmittance and excellent processability. For example, the eighth lens can be formed of glass. The eighth lens can have a predetermined refractive index. For example, the refractive index of the eighth lens can be 1.56 or more. The eighth lens can have a predetermined Abbe number. For example, the Abbe number of the eighth lens can be 60 or more.

[0112] The aspheric lens constituting the imaging lens system can be represented by Equation 1 below.

[0113] Equation 1

[0114]

[0115] In Equation 1, c is the reciprocal of the radius of curvature of the corresponding lens, k is a conic constant, r is the distance from an arbitrary point on the aspheric surface to the optical axis, A, B, C, D, and E are aspheric constants, and Z is the height in the optical axis direction from a certain point on the aspheric surface to the vertex of the corresponding aspheric surface.

[0116] The imaging lens system can include lenses formed of different materials. For example, the first lens, the third lens, and the eighth lens can be formed of a different material from the second lens and the fourth lens to the seventh lens. As a specific example, the first lens, the third lens, and the eighth lens are formed of a glass material having a low coefficient of thermal expansion against external impact and temperature change, and the second lens and the fourth lens to the seventh lens are formed of a plastic material that is easy to process. However, the materials of the first lens to the eighth lens are not limited to the above-described example. For example, the first lens and the third lens can be formed of a glass material, and the second lens and the fourth lens to the eighth lens can be formed of a plastic material.

[0117] The imaging lens system can include a stop, an imaging surface, and a filter.

[0118] The stop can be disposed between the lenses. For example, the stop can be disposed between the second lens and the third lens. As another example, the stop can be disposed on an image side of a lens having a positive refractive power, or between a lens having a positive refractive power and a lens having a positive refractive power. The imaging surface can be formed at a point at which light refracted by the first lens to the eighth lens forms an image. The imaging surface can be formed by an image sensor. For example, the imaging surface can be formed on a surface of the image sensor or on an inner side of the image sensor. The filter can be disposed between the eighth lens and the imaging surface. The filter can block light of a specific wavelength. For example, the filter can block light of an infrared wavelength.

[0119] The camera module according to the ninth aspect of the disclosure can include one of the imaging lens systems according to the first aspect to the eighth aspect. For example, the camera module according to the ninth aspect can include the imaging lens system according to the first aspect. The camera module according to the ninth aspect can include a lens barrel and a housing. In the camera module according to the ninth aspect, the lens barrel can be configured to accommodate the imaging lens system, and the housing can be configured to accommodate the lens barrel and an image sensor. In the camera module according to the ninth aspect, the lens barrel and the housing can be formed of different materials or materials having different coefficients of thermal expansion. For example, the lens barrel can be formed of a plastic material, and the housing can be formed of a metal material. As another example, the lens barrel can be formed of a material having a CTE of 6 × 10 -5 / °C, and the housing can be formed of a material having a CTE of 2.3 × 10 -5 / °C.

[0120] Hereinafter, exemplary embodiments of the disclosure will be described in detail with reference to the accompanying illustrative drawings.

[0121] First, an imaging lens system according to a first embodiment will be described with reference to Figure 1 ​

[0122] The imaging lens system 100 can include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a seventh lens 170, and an eighth lens 180.

[0123] The first lens 110 can have a negative refractive power, and can have a convex object side surface and a concave image side surface. The second lens 120 can have a positive refractive power, and can have a concave object side surface and a convex image side surface. The third lens 130 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The fourth lens 140 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The fifth lens 150 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The sixth lens 160 can have a negative refractive power, and can have a convex object side surface and a concave image side surface. The seventh lens 170 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The eighth lens 180 can have a positive refractive power, and can have a convex object side surface and a concave image side surface.

[0124] The imaging lens system 100 can further include a stop ST, a filter IF, and an imaging plane IP. The stop ST can be disposed between the second lens 120 and the third lens 130. The imaging plane IP can be formed on an image sensor IS, and the filter IF can be disposed between the eighth lens 180 and the imaging plane IP.

[0125] Figure 2 Aberration curves of the imaging lens system according to the present embodiment are shown, and Figure 3 and Figure 4 Modulation transfer function (MTF) characteristics and a change amount of back focal length (ΔBFL: µm) according to temperature in the imaging lens system according to the present embodiment are shown.

[0126] Tables 1 and 2 show lens characteristics and aspherical values of the imaging lens system according to the present embodiment.

[0127] Table 1

[0128]

[0129] Table 2

[0130]

[0131] An imaging lens system according to a second embodiment will be described with reference to Figure 5 An imaging lens system according to a second embodiment will be described with reference to

[0132] The imaging lens system 200 can include a first lens 210, a second lens 220, a third lens 230, a fourth lens 240, a fifth lens 250, a sixth lens 260, a seventh lens 270, and an eighth lens 280.

[0133] The first lens 210 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The second lens 220 can have a positive refractive power, and can have a concave object side surface and a convex image side surface. The third lens 230 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The fourth lens 240 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The fifth lens 250 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The sixth lens 260 can have a negative refractive power, and can have a convex object side surface and a concave image side surface. The seventh lens 270 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The eighth lens 280 can have a positive refractive power, and can have a convex object side surface and a concave image side surface.

[0134] The imaging lens system 200 can further include a stop ST, a filter IF, and an imaging plane IP. The stop ST can be disposed between the second lens 220 and the third lens 230. The imaging plane IP can be formed on an image sensor IS, and the filter IF can be disposed between the eighth lens 280 and the imaging plane IP.

[0135] Figure 6 Aberration curves of the imaging lens system according to the present embodiment are shown, and Figure 7 and Figure 8 Changes in MTF characteristics and back focal length (ΔBFL: µm) according to temperature in the imaging lens system according to the present embodiment are shown.

[0136] Tables 3 and 4 show lens characteristics and aspherical values of the imaging lens system according to the present embodiment.

[0137] Table 3

[0138]

[0139] Table 4

[0140]

[0141] An imaging lens system according to a third embodiment will be described with reference to Figure 9 An imaging lens system according to a third embodiment will be described with reference to

[0142] The imaging lens system 300 can include a first lens 310, a second lens 320, a third lens 330, a fourth lens 340, a fifth lens 350, a sixth lens 360, a seventh lens 370, and an eighth lens 380.

[0143] The first lens 310 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The second lens 320 can have a positive refractive power, and can have a concave object side surface and a convex image side surface. The third lens 330 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The fourth lens 340 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The fifth lens 350 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The sixth lens 360 can have a negative refractive power, and can have a convex object side surface and a concave image side surface. The seventh lens 370 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The eighth lens 380 can have a positive refractive power, and can have a convex object side surface and a concave image side surface.

[0144] The imaging lens system 300 can further include a stop ST, a filter IF, and an imaging plane IP. The stop ST can be disposed between the second lens 320 and the third lens 330. The imaging plane IP can be formed on an image sensor IS, and the filter IF can be disposed between the eighth lens 380 and the imaging plane IP.

[0145] Figure 10 Aberration curves of the imaging lens system according to the present embodiment are shown, and Figure 11 and Figure 12 The MTF characteristics and the amount of change in back focal length (ΔBFL: µm) according to temperature in the imaging lens system according to the present embodiment are shown.

[0146] Tables 5 and 6 show lens characteristics and aspherical values of the imaging lens system according to the present embodiment.

[0147] Table 5

[0148]

[0149] Table 6

[0150]

[0151] An imaging lens system according to a fourth embodiment will be described with reference to Figure 13 An imaging lens system according to a fourth embodiment will be described with reference to

[0152] The imaging lens system 400 can include a first lens 410, a second lens 420, a third lens 430, a fourth lens 440, a fifth lens 450, a sixth lens 460, a seventh lens 470, and an eighth lens 480.

[0153] The first lens 410 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The second lens 420 can have a positive refractive power, and can have a concave object side surface and a convex image side surface. The third lens 430 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The fourth lens 440 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The fifth lens 450 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The sixth lens 460 can have a negative refractive power, and can have a convex object side surface and a concave image side surface. The seventh lens 470 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The eighth lens 480 can have a positive refractive power, and can have a convex object side surface and a concave image side surface.

[0154] The imaging lens system 400 can further include a stop ST, a filter IF, and an imaging plane IP. The stop ST can be disposed between the second lens 420 and the third lens 430. The imaging plane IP can be formed on an image sensor IS, and the filter IF can be disposed between the eighth lens 480 and the imaging plane IP.

[0155] Figure 14 Aberration curves of the imaging lens system according to the present embodiment are shown, and Figure 15 and Figure 16 Changes in MTF characteristics and back focal length (ΔBFL: µm) according to temperature in the imaging lens system according to the present embodiment are shown.

[0156] Tables 7 and 8 show lens characteristics and aspherical values of the imaging lens system according to the present embodiment.

[0157] Table 7

[0158]

[0159] Table 8

[0160]

[0161] An imaging lens system according to a fifth embodiment will be described with reference to Figure 17 An imaging lens system according to a fifth embodiment will be described with reference to

[0162] The imaging lens system 500 can include a first lens 510, a second lens 520, a third lens 530, a fourth lens 540, a fifth lens 550, a sixth lens 560, a seventh lens 570, and an eighth lens 580.

[0163] The first lens 510 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The second lens 520 can have a positive refractive power, and can have a concave object side surface and a convex image side surface. The third lens 530 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The fourth lens 540 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The fifth lens 550 can have a positive refractive power, and can have a concave object side surface and a convex image side surface. The sixth lens 560 can have a negative refractive power, and can have a convex object side surface and a concave image side surface. The seventh lens 570 can have a positive refractive power, and can have a concave object side surface and a convex image side surface. The eighth lens 580 can have a positive refractive power, and can have a convex object side surface and a concave image side surface.

[0164] The imaging lens system 500 can further include a stop ST, a filter IF, and an imaging plane IP. The stop ST can be disposed between the second lens 520 and the third lens 530. The imaging plane IP can be formed on an image sensor IS, and the filter IF can be disposed between the eighth lens 580 and the imaging plane IP.

[0165] Figure 18 Aberration curves of the imaging lens system according to the present embodiment are shown, and Figure 19 and Figure 20 Changes in MTF characteristics and back focal length (ΔBFL: µm) according to temperature in the imaging lens system according to the present embodiment are shown.

[0166] Tables 9 and 10 show lens characteristics and aspherical values of the imaging lens system according to the present embodiment.

[0167] Table 9

[0168]

[0169] Table 10

[0170]

[0171] An imaging lens system according to a sixth embodiment will be described with reference to Figure 21 An imaging lens system according to a sixth embodiment will be described with reference to

[0172] The imaging lens system 600 can include a first lens 610, a second lens 620, a third lens 630, a fourth lens 640, a fifth lens 650, a sixth lens 660, a seventh lens 670, and an eighth lens 680.

[0173] The first lens 610 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The second lens 620 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The third lens 630 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The fourth lens 640 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The fifth lens 650 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The sixth lens 660 can have a negative refractive power, and can have a convex object side surface and a concave image side surface. The seventh lens 670 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The eighth lens 680 can have a positive refractive power, and can have a convex object side surface and a convex image side surface.

[0174] The imaging lens system 600 can further include a stop ST, a filter IF, and an imaging plane IP. The stop ST can be disposed between the second lens 620 and the third lens 630. The imaging plane IP can be formed on an image sensor IS, and the filter IF can be disposed between the eighth lens 680 and the imaging plane IP.

[0175] Figure 22 Aberration curves of the imaging lens system according to the present embodiment are shown, and Figure 23 and Figure 24 The MTF characteristics and the amount of change in back focal length (ΔBFL: µm) according to temperature in the imaging lens system according to the present embodiment are shown.

[0176] Tables 11 and 12 show lens characteristics and aspherical values of the imaging lens system according to the present embodiment.

[0177] Table 11

[0178]

[0179] Table 12

[0180]

[0181] An imaging lens system according to a seventh embodiment will be described with reference to Figure 25 An imaging lens system according to a seventh embodiment will be described with reference to

[0182] The imaging lens system 700 can include a first lens 710, a second lens 720, a third lens 730, a fourth lens 740, a fifth lens 750, a sixth lens 760, a seventh lens 770, and an eighth lens 780.

[0183] The first lens 710 can have a negative refractive power, and can have a convex object side surface and a concave image side surface. The second lens 720 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The third lens 730 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The fourth lens 740 can have a negative refractive power, and can have a concave object side surface and a concave image side surface. The fifth lens 750 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The sixth lens 760 can have a negative refractive power, and can have a convex object side surface and a concave image side surface. The seventh lens 770 can have a positive refractive power, and can have a convex object side surface and a convex image side surface. The eighth lens 780 can have a positive refractive power, and can have a convex object side surface and a convex image side surface.

[0184] The imaging lens system 700 can further include a stop ST, a filter IF, and an imaging plane IP. The stop ST can be disposed between the second lens 720 and the third lens 730. The imaging plane IP can be formed on an image sensor IS, and the filter IF can be disposed between the eighth lens 780 and the imaging plane IP.

[0185] Figure 26 Aberration curves of the imaging lens system according to the present embodiment are shown, and Figure 27 and Figure 28 Changes in MTF characteristics and back focal length according to temperature (ΔBFL: µm) in the imaging lens system according to the present embodiment are shown.

[0186] Tables 13 and 14 show lens characteristics and aspherical values of the imaging lens system according to the present embodiment.

[0187] Table 13

[0188]

[0189] Table 14

[0190]

[0191] Tables 15 to 18 show optical characteristic values and conditional expression values of the imaging lens system according to the first embodiment to the seventh embodiment.

[0192] Table 15

[0193]

[0194] Table 16

[0195]

[0196] Table 17

[0197]

[0198] Table 18

[0199]

[0200] Will refer to Figure 29 A camera module according to one or more embodiments is described.

[0201] The camera module 10 according to one or more embodiments of the present disclosure may include a lens barrel 20, a housing 30, and an image sensor IS. Furthermore, the camera module 10 may include an imaging lens system. For example, the camera module 10 according to one or more embodiments may include one of the imaging lens systems 100, 200, 300, 400, 500, 600, and 700 according to the first to seventh embodiments. For example, the first to eighth lenses of the imaging lens system may be sequentially housed within the lens barrel 20. The housing 30 may be configured to house the lens barrel 20 and the image sensor IS.

[0202] The lens barrel 20 and the housing 30 may be coupled together using a coupling means such as an adhesive. A coupling point CP between the lens barrel 20 and the housing 30 may be positioned closer to the object side than the image side surface of the final lenses 180, 280, 380, 480, 580, 680, and 780 of the imaging lens system. For example, the distance from the image side surface of the final lenses 180, 280, 380, 480, 580, 680, and 780 of the imaging lens system to the coupling point CP between the lens barrel 20 and the housing 30 may be greater than zero.

[0203] The camera module 10 according to one or more embodiments of the present disclosure may satisfy one or more of the following conditional expressions:

[0204] 0.60 < BFL / CP < 0.82

[0205] 0.80 < f3 / CP < 1.0

[0206] In the conditional expression, BFL is a distance from an image-side surface of the last lens 180, 280, 380, 480, 580, 680, and 780 of the imaging lens system 100, 200, 300, 400, 500, 600, and 700 housed in the lens barrel 20 to an imaging surface, and f3 is a focal length of the third lens 130, 230, 330, 430, 530, 630, and 730 of the imaging lens system 100, 200, 300, 400, 500, 600, and 700.

[0207] The lens barrel 20 and the housing 30 can be formed of different materials. For example, the lens barrel 20 can be formed of a plastic material, and the housing 30 can be formed of a metal material. As another example, the lens barrel 20 is formed of a material having a CTE of 6 x 10 -5 / °C, and the housing 30 can be formed of a material having a CTE of 2.3 x 10 -5 / °C.

[0208] The camera module 10 configured as described above can minimize a focal length change due to a temperature change through the lens barrel 20, the housing 30, and the imaging lens system 100, 200, 300, 400, 500, 600, 700.

[0209] According to one or more aspects and embodiments disclosed herein, the imaging lens system can achieve constant optical characteristics (focal length) in a wide temperature range from a high temperature environment of 80°C to a low temperature environment of -40°C.

[0210] While specific examples have been shown and described in the foregoing detailed description, various modifications to the examples will be apparent to those of ordinary skill in the art, and the generic principles and features described herein can be applied to other examples without the use of the features and functions of the described examples. The examples described herein are to be understood as illustrative examples only and are not intended to limit the scope of the disclosure. Descriptions of features or aspects in each example should be considered as available for inclusion in other examples, unless the context explicitly excludes them. Proper results can be achieved if the described techniques are performed in a different order, and / or if components in the described systems, architectures, devices, or circuits are combined in a different manner, or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the specific embodiments discussed above, but by the appended claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.

Claims

1. An imaging lens system, characterized in that The imaging lens system includes: A first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in sequence from the object side, wherein the seventh lens has a convex image side surface, wherein the eighth lens has a positive refractive power, and wherein the imaging lens system satisfies the following conditional expression: 1.10 < f3 / f < 1.40, where f is the focal length of the imaging lens system, and f3 is the focal length of the third lens.

2. The imaging lens system according to claim 1, wherein: The first lens has a concave image side surface.

3. The imaging lens system according to claim 1, wherein: The second lens has a convex image side surface.

4. The imaging lens system according to claim 1, wherein: The third lens has a convex image side surface.

5. The imaging lens system according to claim 1, wherein: The fourth lens has a concave image side surface.

6. The imaging lens system according to claim 1, wherein: The fifth lens has a convex image side surface.

7. The imaging lens system according to claim 1, wherein: The sixth lens has a concave image side surface.

8. A camera module, characterized in that The camera module includes: A housing; A lens barrel disposed in the housing and accommodating the imaging lens system according to any one of claims 1 to 7; and An image sensor disposed in the housing at the imaging plane of the imaging lens system.

9. The camera module according to claim 8, wherein: The connection point between the lens barrel and the housing is closer to the object side than the image side surface of the eighth lens, and wherein the camera module satisfies one or more of the following conditional expressions: 0.60 < BFL / CP < 0.82, and 0.80 < f3 / CP < 1.0, where CP is the connection point between the lens barrel and the housing, and BFL is the distance from the image side surface of the eighth lens to the imaging plane.

10. An imaging lens system, characterized in that The imaging lens system includes: A first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in sequence from the object side, wherein the imaging lens system satisfies the following conditional expression: 1.0 < (L1DTn + L4DTn) / (L5DTn + L8DTn) < 1.4, where L1DTn is the refractive index change rate of the first lens according to temperature change, L4DTn is the refractive index change rate of the fourth lens according to temperature change, L5DTn is the refractive index change rate of the fifth lens according to temperature change, and L8DTn is the refractive index change rate of the eighth lens according to temperature change.

11. The imaging lens system according to claim 10, wherein: The first lens has a concave image side surface.

12. The imaging lens system according to claim 10, wherein: The second lens has a convex image side surface.

13. The imaging lens system according to claim 10, wherein: The third lens has a convex image side surface.

14. The imaging lens system according to claim 10, wherein: The fourth lens has a concave image side surface.

15. The imaging lens system according to claim 10, wherein: The fifth lens has a convex image side surface.

16. The imaging lens system according to claim 10, wherein: The sixth lens has a concave image side surface.

17. The imaging lens system according to claim 10, wherein: The seventh lens has a convex image side surface.

18. The imaging lens system according to claim 10, wherein: The imaging lens system satisfies the following conditional expression: 4.0(10 -6 / ℃)<|L3DTn|<8.0(10 -6 / ℃), where L3DTn is the refractive index change rate of the third lens according to temperature change.

19. A camera module, characterized in that The camera module includes: A housing; A lens barrel disposed in the housing and accommodating the imaging lens system according to any one of claims 10 to 18; and An image sensor disposed in the housing at the imaging plane of the imaging lens system, The lens barrel has a first thermal expansion coefficient, and the housing has a second thermal expansion coefficient different from the first thermal expansion coefficient.

20. An imaging lens system, characterized in that The imaging lens system comprises: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are arranged in order from the object side. The seventh lens has a convex image-side surface. wherein the eighth lens has positive refractive power, and Wherein, the imaging lens system satisfies the following conditional expression: 4.0(10 -6 / ℃)<|L3DTn|<8.0(10 -6 / ℃), Wherein, L3DTn is the refractive index change rate of the third lens according to temperature change.

21. A camera module, characterized in that The camera module includes: case; a lens barrel provided in the housing and accommodating the imaging lens system according to claim 20; and An image sensor is provided in the housing at an imaging surface of the imaging lens system.

Images