Imaging lens system

Abstract

The imaging lens system comprises 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 which are sequentially arranged from the object side of the imaging lens system to the imaging surface of the imaging lens system along the optical axis of the imaging lens system, the third lens has a convex image side surface in a paraxial region thereof, and the imaging lens system satisfies the conditional expression 0.3 lt; f / f4lt; f is the focal length of the imaging lens system, and f4 is the focal length of the fourth lens.

Description

[0002] , Cross - reference to related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10 - 2024 - 0121066, filed on September 5, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. Technical field

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

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

[0005] Early small surveillance cameras were designed to capture images of obstacles in neighboring vehicles, and thus not only had relatively low resolution, but the resolution varied greatly according to temperature changes between - 40°C and 80°C. However, as the requirements for the autonomous driving function of vehicles increase, it may be necessary to develop a surveillance camera with high resolution and certain optical characteristics even under harsh temperature conditions. Summary of the utility model

[0006] The present summary section is intended to introduce, in a brief form, a selection of concepts that will be further described in the detailed implementation section below. The present summary section is not intended to identify the key features or essential features of the claimed subject matter, nor is it intended to assist in determining the scope of the claimed subject matter.

[0007] In one 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 sequentially arranged along the optical axis of the imaging lens system from the object side of the imaging lens system toward the imaging surface of the imaging lens system, where the second lens has a positive refractive power, the third lens has a convex image side surface in its paraxial region, and the imaging lens system satisfies the conditional expression 0.3 < f / f4 < 0.4, where f is the focal length of the imaging lens system, and f4 is the focal length of the fourth lens. <​​​​​​​​

[0011] The fifth lens may have a convex object side surface in its paraxial region.

[0012] The sixth lens may have a convex object side surface in its paraxial region.

[0013] The sixth lens may have a concave object side surface in its paraxial region.

[0014] The seventh lens may have a convex object side surface in its paraxial region.

[0015] The eighth lens may have a convex object side surface in its paraxial region.

[0016] 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 sequentially arranged along an optical axis of the imaging lens system from an object side of the imaging lens system toward an imaging surface of the imaging lens system, wherein the second lens has a positive refractive power, and the imaging lens system satisfies the conditional expression 2.0 < TTL / f4 < 3.0, where TTL is a distance along the optical axis from an object side surface of the first lens to the imaging surface, and f4 is a focal length of the fourth lens.

[0017] The object side surface of the first lens may be convex in its paraxial region.

[0018] The second lens may have a concave object side surface in its paraxial region.

[0019] The fourth lens may have a convex object side surface in its paraxial region

[0020] The fifth lens may have a convex object side surface in its paraxial region.

[0021] The sixth lens may have a convex object side surface in its paraxial region. <​​​​​​​​​​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 sequentially arranged along an optical axis of the imaging lens system from an object side of the imaging lens system toward an imaging surface of the imaging lens system, wherein the imaging lens system satisfies a conditional expression -1.6 < R3 / f4 < -0.4, where R3 is a radius of curvature of an object side surface of the second lens at the optical axis, and f4 is a focal length of the fourth lens.

[0026] The second lens may have a positive refractive power.

[0027] Other features and aspects will be apparent from the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a configuration diagram of an imaging lens system according to a first embodiment of the present disclosure.

[0029] Figure 2 shows Figure 1 the aberration curves of the imaging lens system shown in

[0030] Figure 3 is a configuration diagram of an imaging lens system according to a second embodiment of the present disclosure.

[0031] Figure 4 shows Figure 3 the aberration curves of the imaging lens system shown in

[0032] Figure 5 is a configuration diagram of an imaging lens system according to a third embodiment of the present disclosure.

[0033] Figure 6 shows Figure 5 the aberration curves of the imaging lens system shown in

[0034] Figure 7 is a configuration diagram of an imaging lens system according to a fourth embodiment of the present disclosure.

[0035] Figure 8 shows Figure 7 the aberration curves of the imaging lens system shown in

[0036] Figure 9 is a configuration diagram of an imaging lens system according to a fifth embodiment of the present disclosure.

[0037] Figure 10 shows Figure 9 the aberration curves of the imaging lens system shown in

[0038] Figure 11This is a configuration diagram of an imaging lens system according to the sixth embodiment of this disclosure.

[0039] Figure 12 It shows Figure 11 The aberration curves of the imaging lens system are shown.

[0040] Figure 13 This is a configuration diagram of an imaging lens system according to the seventh embodiment of this disclosure.

[0041] Figure 14 It shows Figure 13 The aberration curves of the imaging lens system are shown.

[0042] Throughout the accompanying drawings and detailed embodiments, the same reference numerals refer to the same elements. For purposes of clarity, illustration, and convenience, the drawings may not be drawn to scale, and the relative dimensions, scale, and depiction of elements in the drawings may be exaggerated. Detailed Implementation

[0043] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein, except for operations that must occur in a specific order, as will become apparent upon understanding the disclosure of this application. Furthermore, for clarity and conciseness, descriptions of features well-known in the art may be omitted.

[0044] The features described herein may be implemented in various forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein are provided merely to illustrate some of the many possible ways in which the methods, apparatuses, and / or systems described herein will become apparent upon understanding the disclosure of this application.

[0045] Throughout this specification, when an element such as a layer, region, or substrate is described as being "on," "connected to," or "attached to" another element, the element may be directly "on," directly "connected to," or directly "attached to" the other element, or there may be one or more other elements between the element and the other element. Conversely, when an element is described as being "directly on," "directly connected to," or "directly attached to" another element, there are no other elements between the element and the other element.

[0046] As used herein, the term “and / or” includes any one of the associated listed items and any combination of any two or more items.

[0047] Although terms such as “first,” “second,” and “third” may be used herein to describe various components, parts, regions, layers, or sections, these components, parts, regions, layers, or sections are not limited by these terms. Rather, these terms are used only to distinguish one component, part, region, layer, or section from another. Therefore, without departing from the teachings of the examples described herein, the first component, first part, first region, first layer, or first section mentioned in these examples may also be referred to as a second component, second part, second region, second layer, or second section.

[0048] Spatial relative terms such as “above,” “above,” “below,” and “under” may be used herein for descriptive convenience to describe the relationship of one element relative to another, as shown in the accompanying drawings. In addition to covering the orientation depicted in the drawings, these spatial relative terms are intended to also cover different orientations of the device in use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “above” another element would be located “below” or “under” that other element. Thus, depending on the spatial orientation of the device, the term “above” covers both orientations of “above” and “below”. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0049] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the terms “a,” “an,” and “the” are intended to include the plural form as well. The terms “comprising,” “including,” and “having” indicate the presence of the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0050] In this specification, the first lens refers to the lens closest to the object (or the subject being photographed), and the eighth lens refers to the lens closest to the imaging plane (or image sensor). In this specification, the radius of curvature, the thickness of the lens or other component, the distance between lenses or other components, the TTL (distance along the optical axis from the object-side surface of the first lens to the imaging plane), the IMGHT (height of the imaging plane), and the focal length are expressed in millimeters (mm). Furthermore, the rate of change of refractive index (DTn) and coefficient of thermal expansion (CTE) described in this specification are expressed in ppm / °C, where ppm represents parts per million.

[0051] The thickness of the lens or other components, the distance between the lenses or other components, and the TTL are measured along the optical axis.

[0052] Furthermore, in the description of lens shape, stating that the surface of the lens is convex means that the paraxial region of the surface is convex, and stating that the surface of the lens is concave means that the paraxial region of the surface is concave.

[0053] Therefore, even when the surface of the reflecting lens is convex, the edge portion of that surface can be concave. Similarly, even when the surface of the reflecting lens is concave, the edge portion of that surface can be convex.

[0054] The paraxial region of a lens surface is a very narrow area on the lens surface that is close to the optical axis.

[0055] More specifically, the paraxial region of the lens surface is the central portion of the lens surface that surrounds and includes the optical axis of the lens surface, in which light rays incident on the lens surface form a small angle θ with the optical axis, and the approximations sinθ≈θ, tanθ≈θ, and cosθ≈1 are valid.

[0056] The imaging lens system according to the first aspect of the present disclosure may include a plurality of lenses. For example, the imaging lens system according to the first aspect may 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 sequentially arranged along the optical axis of the imaging lens system from the object side of the imaging lens system toward the imaging surface of the imaging lens system. The imaging lens system according to the first aspect may include a lens having a positive refractive power. For example, in the imaging lens system according to the first aspect, the second lens may have a positive refractive power. The imaging lens system according to the first aspect may include a lens having a convex image side surface. For example, in the imaging lens system according to the first aspect, the third lens may have a convex image side surface. The imaging lens system according to the first aspect may satisfy a specific conditional expression. For example, the imaging lens system according to the first aspect may satisfy the conditional expression 0.3 < f / f4 < 0.4, where f is the focal length of the imaging lens system, and f4 is the focal length of the fourth lens.

[0057] The imaging lens system according to the second aspect of the present disclosure may include a plurality of lenses. For example, the imaging lens system according to the second aspect may 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 sequentially arranged along the optical axis of the imaging lens system from the object side of the imaging lens system toward the imaging surface of the imaging lens system. The imaging lens system according to the second aspect may include a lens having a positive refractive power. For example, in the imaging lens system according to the second aspect, the second lens may have a positive refractive power. The imaging lens system according to the second aspect may satisfy a specific conditional expression. For example, the imaging lens system according to the second aspect may satisfy the conditional expression 2.0 < TTL / f4 < 3.0, where TTL is the distance along the optical axis from the object side surface of the first lens to the imaging surface, and f4 is the focal length of the fourth lens.

[0058] The imaging lens system according to the third aspect of the present disclosure may include a plurality of lenses. For example, the imaging lens system according to the third aspect may 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 sequentially arranged along the optical axis of the imaging lens system from the object side of the imaging lens system toward the imaging surface of the imaging lens system. The imaging lens system according to the third aspect may include an aperture stop. For example, the imaging lens system according to the third aspect may include an aperture stop disposed between the fourth lens and the fifth lens. The imaging lens system according to the third aspect may include a lens made of a glass material. For example, in the imaging lens system according to the third aspect, the first lens, the second lens, the fourth lens, the sixth lens, and the seventh lens may be made of a glass material. The imaging lens system according to the third aspect may include a cemented lens.

[0059] For example, in the imaging lens system according to the third aspect, the sixth lens and the seventh lens may be cemented to each other. Specifically, in the imaging lens system according to the third aspect, the distance between the sixth lens and the seventh lens (the distance along the optical axis from the image side surface of the sixth lens to the object side surface of the seventh lens) may be less than about 0.01 mm, and may be filled with an adhesive, and the radius of curvature of the image side surface of the sixth lens and the radius of curvature of the object side surface of the seventh lens may be substantially equal to each other.

[0060] The imaging lens system according to the fourth aspect of the present disclosure may include a plurality of lenses. For example, the imaging lens system according to the fourth aspect may 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 sequentially arranged along the optical axis of the imaging lens system from the object side of the imaging lens system toward the imaging surface of the imaging lens system. The imaging lens system according to the fourth aspect may include an aperture stop. For example, the imaging lens system according to the fourth aspect may include an aperture stop disposed between the fourth lens and the fifth lens. The imaging lens system according to the fourth aspect may include a lens having specific optical characteristics. For example, in the imaging lens system according to the fourth aspect, the fourth lens may satisfy any one or both of the conditional expressions 1.0 < L4DnT < 4.0 and 5.0 < L4CTE < 9.0 (based on a wavelength of 587.6 nm). In these conditional expressions, L4DnT is the refractive index change rate of the fourth lens according to temperature change expressed in ppm / °C, and L4CTE is the thermal expansion coefficient of the fourth lens expressed in ppm / °C.

[0061] The imaging lens system according to the fifth aspect of the present disclosure may 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 sequentially arranged along the optical axis of the imaging lens system from the object side of the imaging lens system toward the imaging surface of the imaging lens system, and may satisfy any one or any combination of any two or more of the following conditional expressions:

[0062] 0.3 < f / f4 < 0.4 (conditional expression 1)

[0063] -1.0 < L4DnT < 4.0 (ppm / °C) (conditional expression 2)

[0064] 5.0 < L4CTE < 9.0 (ppm / °C) (conditional expression 3)

[0065] 1.65 < Nd4 < 1.90 (conditional expression 4)

[0066] In the above conditional expressions, f is the focal length of the imaging lens system, f4 is the focal length of the fourth lens, L4DnT is the refractive index change rate of the fourth lens according to temperature change, L4CTE is the thermal expansion coefficient of the fourth lens, and Nd4 is the refractive index of the fourth lens.

[0067] The imaging lens system according to the sixth aspect of the present disclosure may 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 sequentially arranged along the optical axis of the imaging lens system from the object side of the imaging lens system toward the imaging surface of the imaging lens system, and may satisfy any one or any combination of any two or more of the following conditional expressions:

[0068] -1.0 < f1 / f4 < -0.20 (Conditional Expression 5)

[0069] 1.2 < f2 / f4 < 3.20 (Conditional Expression 6)

[0070] -8.0 < f3 / f4 < -1.0 (Conditional Expression 7)

[0071] 0.80 < f5 / f4 < 1.80 (Conditional Expression 8)

[0072] -1.0 < f6 / f4 < -0.20 (Conditional Expression 9)

[0073] 0.20 < f7 / f4 < 1.20 (Conditional Expression 10)

[0074] 1.0 < f8 / f4 < 90 (Conditional Expression 11)

[0075] 2.0 < TTL / f4 < 3.0 (Conditional Expression 12)

[0076] 1.2 < R1 / f4 < 2.40 (Conditional Expression 13)

[0077] -1.6 < R3 / f4 < -0.4 (Conditional Expression 14)

[0078] In the above conditional expressions, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third 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, f8 is the focal length of the eighth lens, TTL is the distance along the optical axis from the object side surface of the first lens to the imaging surface, R1 is the curvature radius of the object side surface of the first lens at the optical axis, and R3 is the curvature radius of the object side surface of the second lens at the optical axis.

[0079] The imaging lens system according to the seventh aspect of the present disclosure may 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 sequentially arranged along the optical axis of the imaging lens system from the object side of the imaging lens system toward the imaging surface of the imaging lens system, and may satisfy any one or any combination of any two or more of the following conditional expressions:

[0080] -2.0 < f6 / f < -1.2 (Conditional Expression 15)

[0081] 1.0 < f7 / f < 2.6 (Conditional Expression 16)

[0082] -1.2 < f6 / f7 < -0.6 (Conditional Expression 17)

[0083] -1.6 < (R1 + R3) / R4 < -0.6 (Conditional Expression 18)

[0084] 0.8 < (R5 + R6) / R3 < 1.4 (Conditional Expression 19)

[0085] -1.4 < (R4 + R5) / R7 < -0.8 (Conditional Expression 20)

[0086] In the above conditional expressions, R4 is the radius of curvature of the image-side surface of the second lens at the optical axis, R5 is the radius of curvature of the object-side surface of the third lens at the optical axis, R6 is the radius of curvature of the image-side surface of the third lens at the optical axis, and R7 is the radius of curvature of the object-side surface of the fourth lens at the optical axis.

[0087] The imaging lens system according to the eighth aspect of the present disclosure may include any combination of any two or more of the first aspect to the seventh aspect having the following characteristics. For example, the imaging lens system according to the eighth aspect may include the characteristics of the first aspect and may satisfy any one or any combination of any two or more of the conditional expressions according to the fifth aspect. As another example, the imaging lens system according to the eighth aspect may include the characteristics of the second aspect and may satisfy any one or any combination of any two or more of the conditional expressions according to the sixth aspect or the seventh aspect.

[0088] An imaging lens system according to the first to eighth aspects may include any one or any combination of any two or more of the first to eighth lenses having the characteristics described below. As an example, an imaging lens system according to the first aspect may include one of the first to eighth lenses having the characteristics described below. As another example, an imaging lens system according to the second aspect may include any combination of any two or more of the first to eighth lenses having the characteristics described below. However, an imaging lens system according to the above aspects does not necessarily include lenses having the characteristics described below. The characteristics of the first to eighth lenses are described below.

[0089] The first lens may have refractive power. For example, the first lens may have negative refractive power. The first lens may have a convex shape on one surface. For example, the first lens may have a convex object-side surface. The first lens may include a spherical or aspherical surface. For example, both surfaces of the first lens may be spherical. The first lens may be made of a material with high light transmittance and excellent processability. For example, the first lens may be made of glass. The first lens may have properties that are beneficial to improving aberrations. For example, the first lens may have a refractive index of 1.78 or greater and an Abbe number of 40 or greater.

[0090] The second lens may have refractive power. For example, the second lens may have positive refractive power. The second lens may have a concave shape on one surface. For example, the second lens may have a concave object-side surface. The second lens may include a spherical surface. For example, both surfaces of the second lens may be spherical. The second lens may be made of a material with high light transmittance and excellent processability. For example, the second lens may be made of glass. The second lens may have a predetermined refractive index. For example, the refractive index of the second lens may be 1.80 or greater. The second lens may have a predetermined Abbe number. For example, the Abbe number of the second lens may be greater than 30 and less than 50.

[0091] The third lens may have refractive power. For example, the third lens may have negative refractive power. The third lens may have a convex shape on one surface. For example, the third lens may have a convex image-side surface. The third lens may include an aspherical surface. For example, both surfaces of the third lens may be aspherical. The third lens may be made of a material different from that of the second lens. For example, the third lens may be made of a plastic material. The third lens may have a predetermined refractive index. For example, the third lens may have a refractive index of 1.50 or greater. The third lens may have a predetermined Abbe number. For example, the Abbe number of the third lens may be greater than 52.

[0092] The fourth lens may have refractive power. For example, the fourth lens may have positive refractive power. The fourth lens may have a convex shape on one surface. For example, the fourth lens may have a convex object-side surface. The fourth lens may include a spherical surface. For example, both surfaces of the fourth lens may be spherical. The fourth lens may be made of a material different from that of the third lens. For example, the fourth lens may be made of glass. The fourth lens may have a predetermined refractive index. For example, the refractive index of the fourth lens may be 1.7 or greater. The fourth lens may have a predetermined Abbe number. For example, the Abbe number of the fourth lens may be greater than 46.

[0093] The fifth lens may have refractive power. For example, the fifth lens may have positive refractive power. The fifth lens may have a convex shape on one surface. For example, the fifth lens may have a convex object-side surface. The fifth lens may include an aspherical surface. For example, both surfaces of the fifth lens may be aspherical. The fifth lens may be made of a material different from that of the fourth lens. For example, the fifth lens may be made of a plastic material. The fifth lens may have a predetermined refractive index. For example, the refractive index of the fifth lens may be less than 1.6. The fifth lens may have a predetermined Abbe number. For example, the Abbe number of the fifth lens may be greater than 52.

[0094] The sixth lens may have refractive power. For example, the sixth lens may have negative refractive power. The sixth lens may have a convex shape on one surface. For example, the sixth lens may have a convex object-side surface. Alternatively, the sixth lens may have a concave object-side surface and a concave image-side surface. The sixth lens may include a spherical or aspherical surface. For example, both surfaces of the sixth lens may be spherical, or one surface may be aspherical. The sixth lens may be made of a material different from that of the fifth lens. For example, the sixth lens may be made of glass. The sixth lens may have a predetermined refractive index. For example, the refractive index of the sixth lens may be greater than 1.6. The sixth lens may have a predetermined Abbe number. For example, the Abbe number of the sixth lens may be less than 30.

[0095] The seventh lens may have refractive power. For example, the seventh lens may have positive refractive power. The seventh lens may have a convex shape on one surface. For example, the seventh lens may have a convex object-side surface. The seventh lens may include a spherical or aspherical surface. For example, both surfaces of the seventh lens may be spherical, or the image-side surface may be aspherical. The seventh lens may be made of the same material as the sixth lens. For example, the seventh lens may be made of glass. The seventh lens may have a predetermined refractive index. For example, the refractive index of the seventh lens may be 1.5 or greater. The seventh lens may have a predetermined Abbe number. For example, the Abbe number of the seventh lens may be greater than 60. Alternatively, the Abbe number of the seventh lens may be greater than 52. The seventh lens may be cemented to the sixth lens. For example, the radius of curvature of the object-side surface of the seventh lens may be substantially equal to the radius of curvature of the image-side surface of the sixth lens.

[0096] The eighth lens may have refractive power. For example, the eighth lens may have positive refractive power. The eighth lens may have a convex shape on one surface. For example, the eighth lens may have a convex object-side surface. The eighth lens may include an aspherical surface. For example, both surfaces of the eighth lens may be aspherical. Alternatively, both surfaces of the eighth lens may be spherical. The eighth lens may be made of a material different from that of the seventh lens. For example, the eighth lens may be made of a plastic material. The eighth lens may have a predetermined refractive index. For example, the refractive index of the eighth lens may be 1.50 or greater. The eighth lens may have a predetermined Abbe number. For example, the Abbe number of the eighth lens may be 52 or greater.

[0097] The aspherical surface of a lens is defined by the following Equation 1:

[0098]

[0099] In Equation 1, c is the curvature of the lens surface, and is equal to the reciprocal of the radius of curvature of the lens surface at the optical axis. k is the quadratic constant, and r is the distance from any point on the aspherical surface of the lens to the optical axis. Furthermore, constants A to H are aspherical surface coefficients. Z (also called sag) is the distance in a direction parallel to the optical axis between a point on the aspherical surface of the lens at a distance r from the optical axis and a tangent plane perpendicular to the optical axis and intersecting the vertex of the aspherical surface.

[0100] An imaging lens system may include lenses made of different materials. For example, the first, second, fourth, sixth, and seventh lenses may be made of materials different from those of the third, fifth, and eighth lenses. As a specific example, the first, second, fourth, sixth, and seventh lenses may be made of glass, which has a low coefficient of thermal expansion due to external impact and temperature changes, and the third, fifth, and eighth lenses may be made of a plastic material that is easy to process. However, the materials of the first through eighth lenses are not limited to the examples described above. For example, the second lens may be changed to be made of a plastic material, and the third lens may be changed to be made of glass.

[0101] An imaging lens system may include an aperture stop, an imaging plane, and a filter.

[0102] An aperture stop can be positioned between two lenses in a lens system. For example, an aperture stop can be positioned between a fourth lens and a fifth lens. As another example, an aperture stop can be positioned on the object side of a lens made of glass material and having positive refractive power. An imaging plane can be formed at the point where the light refracted by the first to eighth lenses forms an image. The imaging plane can be formed by an image sensor. For example, the imaging plane can be formed on the surface of the image sensor or on the inner layer of the image sensor. A filter can be positioned between the eighth lens and the imaging plane. The filter can block light of a specific wavelength. For example, the filter can block infrared wavelengths of light.

[0103] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0104] Figure 1 This is a configuration diagram of an imaging lens system according to a first embodiment of the present disclosure. Figure 2 It shows Figure 1 The aberration curves of the imaging lens system are shown.

[0105] Reference Figure 1 The imaging lens system 100 may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a seventh lens 170, and an eighth lens 180.

[0106] The first lens 110 can have negative refractive power and can have a convex object-side surface and a concave image-side surface. The second lens 120 can have positive refractive power and can have a concave object-side surface and a convex image-side surface. The third lens 130 can have negative refractive power and can have a concave object-side surface and a convex image-side surface. The fourth lens 140 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The fifth lens 150 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The sixth lens 160 can have negative refractive power and can have a convex object-side surface and a concave image-side surface. The seventh lens 170 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The eighth lens 180 can have positive refractive power and can have a convex object-side surface and a concave image-side surface.

[0107] The imaging lens system 100 may further include an aperture stop ST, a filter IF, and an imaging surface IP. The aperture stop ST may be positioned between the fourth lens 140 and the fifth lens 150. The imaging surface IP may be formed on the image sensor IS, and the filter IF may be positioned between the eighth lens 180 and the imaging surface IP.

[0108] Tables 1 and 2 below show the lens characteristics and aspherical values ​​of the imaging lens system 100.

[0109] Table 1

[0110]

[0111] Table 2

[0112]

[0113]

[0114] Figure 3 This is a configuration diagram of an imaging lens system according to a second embodiment of the present disclosure. Figure 4 It shows Figure 3 The aberration curves of the imaging lens system are shown.

[0115] Reference Figure 3 The imaging lens system 200 may 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.

[0116] The first lens 210 can have negative refractive power and can have a convex object-side surface and a concave image-side surface. The second lens 220 can have positive refractive power and can have a concave object-side surface and a convex image-side surface. The third lens 230 can have negative refractive power and can have a concave object-side surface and a convex image-side surface. The fourth lens 240 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The fifth lens 250 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The sixth lens 260 can have negative refractive power and can have a convex object-side surface and a concave image-side surface. The seventh lens 270 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The eighth lens 280 can have positive refractive power and can have a convex object-side surface and a concave image-side surface.

[0117] The imaging lens system 200 may further include an aperture stop ST, a filter IF, and an imaging surface IP. The aperture stop ST may be positioned between the fourth lens 240 and the fifth lens 250. The imaging surface IP may be formed on the image sensor IS, and the filter IF may be positioned between the eighth lens 280 and the imaging surface IP.

[0118] Tables 3 and 4 below show the lens characteristics and aspherical values ​​of the imaging lens system 200.

[0119] Table 3

[0120]

[0121] Table 4

[0122] Face number S5 S6 S10 S11 S15 S16 k -2.393E+00 -1.600E+01 -1.904E+00 -2.696E+01 9.900E+01 -9.900E+01 A 8.639E-03 1.979E-01 -8.370E-02 -1.549E-01 -4.871E-01 -5.833E-01 B -2.897E-03 8.310E-04 -1.447E-02 -1.635E-02 -1.907E-02 1.170E-02 C -5.604E-05 -2.335E-03 -1.780E-03 -1.840E-03 6.698E-04 6.475E-03 D 2.547E-04 6.823E-04 -2.680E-04 -2.326E-04 5.957E-04 8.096E-04 E -3.889E-05 -1.405E-04 -1.609E-05 0 1.062E-04 2.876E-04 F 0 3.020E-05 1.099E-05 0 0 0 G 0 -6.399E-07 1.081E-05 0 0 0

[0123] Figure 5 This is a configuration diagram of an imaging lens system according to a third embodiment of the present disclosure. Figure 6 It shows Figure 5 The aberration curves of the imaging lens system are shown.

[0124] Reference Figure 5 The imaging lens system 300 may 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.

[0125] The first lens 310 can have negative refractive power and can have a convex object-side surface and a concave image-side surface. The second lens 320 can have positive refractive power and can have a concave object-side surface and a convex image-side surface. The third lens 330 can have negative refractive power and can have a concave object-side surface and a convex image-side surface. The fourth lens 340 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The fifth lens 350 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The sixth lens 360 can have negative refractive power and can have a convex object-side surface and a concave image-side surface. The seventh lens 370 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The eighth lens 380 can have positive refractive power and can have a convex object-side surface and a convex image-side surface.

[0126] The imaging lens system 300 may further include an aperture stop ST, a filter IF, and an imaging surface IP. The aperture stop ST may be positioned between the fourth lens 340 and the fifth lens 350. The imaging surface IP may be formed on the image sensor IS, and the filter IF may be positioned between the eighth lens 380 and the imaging surface IP.

[0127] Tables 5 and 6 below show the lens characteristics and aspherical values ​​of the imaging lens system 300.

[0128] Table 5

[0129]

[0130]

[0131] Table 6

[0132] Face number S5 S6 S10 S11 S15 S16 k -2.212E+00 -1.995E+01 -2.176E+00 9.858E+01 9.900E+01 3.451E+00 A 3.008E-02 2.020E-01 -5.356E-02 -6.523E-02 -5.229E-01 -6.110E-01 B -4.039E-03 -5.851E-04 -1.887E-02 -1.443E-02 -3.051E-02 1.787E-03 C 1.811E-04 -1.630E-03 -3.077E-03 -1.839E-03 -1.558E-03 6.103E-03 D 1.861E-04 3.827E-04 -5.813E-04 -1.932E-04 1.685E-04 7.532E-04 E -1.328E-05 -6.055E-05 -1.202E-04 0 5.991E-05 2.880E-04 F 0 8.122E-06 -2.140E-05 0 0 0 G 0 4.255E-06 0 0 0 0

[0133] Figure 7 This is a configuration diagram of an imaging lens system according to the fourth embodiment of this disclosure. Figure 8 It shows Figure 7 The aberration curves of the imaging lens system are shown.

[0134] Reference Figure 7 The imaging lens system 400 may 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.

[0135] The first lens 410 can have negative refractive power and can have a convex object-side surface and a concave image-side surface. The second lens 420 can have positive refractive power and can have a concave object-side surface and a convex image-side surface. The third lens 430 can have negative refractive power and can have a concave object-side surface and a convex image-side surface. The fourth lens 440 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The fifth lens 450 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The sixth lens 460 can have negative refractive power and can have a convex object-side surface and a concave image-side surface. The seventh lens 470 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The eighth lens 480 can have positive refractive power and can have a convex object-side surface and a concave image-side surface.

[0136] The imaging lens system 400 may further include an aperture stop ST, a filter IF, and an imaging surface IP. The aperture stop ST may be positioned between the fourth lens 440 and the fifth lens 450. The imaging surface IP may be formed on the image sensor IS, and the filter IF may be positioned between the eighth lens 480 and the imaging surface IP.

[0137] Tables 7 and 8 below show the lens characteristics and aspherical values ​​of the imaging lens system 400.

[0138] Table 7

[0139]

[0140] Table 8

[0141]

[0142]

[0143] Figure 9 This is a configuration diagram of an imaging lens system according to the fifth embodiment of this disclosure. Figure 10 It shows Figure 9 The aberration curves of the imaging lens system are shown.

[0144] Reference Figure 9 The imaging lens system 500 may 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.

[0145] The first lens 510 can have negative refractive power and can have a convex object-side surface and a concave image-side surface. The second lens 520 can have positive refractive power and can have a concave object-side surface and a convex image-side surface. The third lens 530 can have negative refractive power and can have a concave object-side surface and a convex image-side surface. The fourth lens 540 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The fifth lens 550 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The sixth lens 560 can have negative refractive power and can have a concave object-side surface and a concave image-side surface. The seventh lens 570 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The eighth lens 580 can have positive refractive power and can have a concave object-side surface and a convex image-side surface.

[0146] The imaging lens system 500 may further include an aperture stop ST, a filter IF, and an imaging surface IP. The aperture stop ST may be positioned between the fourth lens 540 and the fifth lens 550. The imaging surface IP may be formed on the image sensor IS, and the filter IF may be positioned between the eighth lens 580 and the imaging surface IP.

[0147] Tables 9 and 10 below show the lens characteristics and aspherical values ​​of the imaging lens system 500.

[0148] Table 9

[0149]

[0150]

[0151] Table 10

[0152] Face number S5 S6 S10 S11 S15 S16 k -2.239E+00 -3.940E+00 1.461E+01 -4.151E-02 -8.042E+00 9.900E+01 A -2.757E-01 -1.297E-01 -1.089E-01 -1.167E-01 -6.332E-01 -8.184E-01 B 3.302E-02 2.586E-02 -1.679E-02 -2.118E-02 -6.182E-02 -3.722E-02 C -2.058E-03 -2.371E-03 -1.955E-03 -1.808E-03 -7.685E-03 7.518E-04 D 2.627E-04 3.720E-04 -4.136E-04 -2.542E-04 -1.188E-03 -2.752E-04 E 1.997E-05 -1.002E-04 -8.182E-06 0 -1.068E-04 1.746E-04 F 0 3.559E-05 -2.432E-06 0 0 0 G 0 -1.244E-05 2.161E-05 0 0 0

[0153] Figure 11 This is a configuration diagram of an imaging lens system according to the sixth embodiment of this disclosure. Figure 12 It shows Figure 11 The aberration curves of the imaging lens system are shown.

[0154] Reference Figure 11 The imaging lens system 600 may 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.

[0155] The first lens 610 can have negative refractive power and can have a convex object-side surface and a concave image-side surface. The second lens 620 can have positive refractive power and can have a concave object-side surface and a convex image-side surface. The third lens 630 can have negative refractive power and can have a concave object-side surface and a convex image-side surface. The fourth lens 640 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The fifth lens 650 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The sixth lens 660 can have negative refractive power and can have a concave object-side surface and a concave image-side surface. The seventh lens 670 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The eighth lens 680 can have positive refractive power and can have a concave object-side surface and a convex image-side surface.

[0156] The imaging lens system 600 may further include an aperture stop ST, a filter IF, and an imaging surface IP. The aperture stop ST may be positioned between the fourth lens 640 and the fifth lens 650. The imaging surface IP may be formed on the image sensor IS, and the filter IF may be positioned between the eighth lens 680 and the imaging surface IP.

[0157] Tables 11 and 12 below show the lens characteristics and aspherical values ​​of the imaging lens system 600.

[0158] Table 11

[0159]

[0160]

[0161] Table 12

[0162] Face number S5 S6 S10 S11 S15 S16 k -2.217E+00 -3.771E+00 2.524E+01 -4.791E-01 -6.007E+01 8.667E+01 A -2.967E-01 -1.480E-01 -1.033E-01 -1.047E-01 -6.106E-01 -8.814E-01 B 3.800E-02 2.887E-02 -1.562E-02 -1.906E-02 -6.114E-02 -4.293E-02 C -2.369E-03 -2.528E-03 -1.741E-03 -1.582E-03 -7.291E-03 5.949E-04 D 3.539E-04 2.884E-04 -3.560E-04 -2.379E-04 -9.597E-04 -6.490E-04 E -2.145E-05 -7.223E-05 3.069E-07 0 -5.038E-05 -7.005E-05 F 0 -7.974E-06 -8.804E-07 0 0.000E+00 0 G 0 9.521E-06 2.693E-05 0 0 0

[0163] Figure 13 This is a configuration diagram of an imaging lens system according to the seventh embodiment of this disclosure. Figure 14 It shows Figure 13 The aberration curves of the imaging lens system are shown.

[0164] Reference Figure 13 The imaging lens system 700 may 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.

[0165] The first lens 710 can have negative refractive power and can have a convex object-side surface and a concave image-side surface. The second lens 720 can have positive refractive power and can have a concave object-side surface and a convex image-side surface. The third lens 730 can have negative refractive power and can have a concave object-side surface and a convex image-side surface. The fourth lens 740 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The fifth lens 750 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The sixth lens 760 can have negative refractive power and can have a concave object-side surface and a concave image-side surface. The seventh lens 770 can have positive refractive power and can have a convex object-side surface and a convex image-side surface. The eighth lens 780 can have positive refractive power and can have a convex object-side surface and a concave image-side surface.

[0166] The imaging lens system 700 may further include an aperture stop ST, a filter IF, and an imaging surface IP. The aperture stop ST may be positioned between the fourth lens 740 and the fifth lens 750. The imaging surface IP may be formed on the image sensor IS, and the filter IF may be positioned between the eighth lens 780 and the imaging surface IP.

[0167] Tables 13 and 14 below show the lens characteristics and aspherical values ​​of the imaging lens system 700.

[0168] Table 13

[0169]

[0170] Table 14

[0171] Face number S5 S6 S10 S11 S12 S14 k -2.603E+00 -4.489E+00 3.222E+01 -1.942E+01 1.058E+01 -3.785E+01 A -2.751E-01 -2.480E-01 2.007E-02 -8.888E-02 7.513E-02 3.232E-02 B 2.986E-02 4.032E-02 -1.101E-02 -3.630E-02 -3.807E-02 -1.256E-03 C -5.057E-03 -7.651E-03 -1.168E-03 1.454E-04 4.783E-03 3.722E-03 D 1.694E-04 7.026E-04 -8.446E-05 3.358E-04 7.755E-05 -1.805E-04 E -4.705E-05 -2.493E-04 3.997E-06 0 1.915E-04 2.306E-04 F 0 5.276E-05 8.086E-06 0 4.695E-05 -5.261E-05 G 0 1.231E-05 1.067E-05 0 4.843E-06 6.586E-05

[0172] Tables 15 to 17 below show the optical characteristic values ​​and conditional expression values ​​of the imaging lens systems 100 to 700 according to the first to seventh embodiments.

[0173] Table 15

[0174]

[0175] Table 16

[0176]

[0177] Table 17

[0178]

[0179] This disclosure describes an imaging lens system with certain optical characteristics (focal length) over a wide temperature range, from high-temperature environments of 80°C to low-temperature environments of -40°C.

[0180] While this disclosure includes specific examples, it will be apparent upon understanding this disclosure that various changes in form and detail may be made to these examples without departing from the spirit and scope of the claims and their equivalents. The description of features or aspects in each example should be considered applicable to similar features or aspects in other examples. Suitable results may still be achieved if the described techniques are performed in a different order, and / or if components in the described system, architecture, device, or circuit are combined in different ways and / or replaced or supplemented by other components or their equivalents. Therefore, the scope of this disclosure is not limited by the specific embodiments but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents should be understood to be included in this 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 are arranged sequentially along the optical axis of the imaging lens system from the object side of the imaging lens system toward the imaging surface of the imaging lens system. The second lens has positive refractive power. The third lens has a convex image-side surface in its paraxial region, and The imaging lens system satisfies the following conditional expression: 0.3 <f / f4<0.4 Where f is the focal length of the imaging lens system, and f4 is the focal length of the fourth lens.

2. The imaging lens system according to claim 1, characterized in that, The first lens has a convex object-side surface in its paraxial region.

3. The imaging lens system according to claim 1, characterized in that, The second lens has a concave object-side surface in its paraxial region.

4. The imaging lens system according to claim 1, characterized in that, The fourth lens has a convex object-side surface in its paraxial region.

5. The imaging lens system according to claim 1, characterized in that, The fifth lens has a convex object-side surface in its paraxial region.

6. The imaging lens system according to claim 1, characterized in that, The sixth lens has a convex object-side surface in its paraxial region.

7. The imaging lens system according to claim 1, characterized in that, The sixth lens has a concave object-side surface in its paraxial region.

8. The imaging lens system according to claim 1, characterized in that, The seventh lens has a convex object-side surface in its paraxial region.

9. The imaging lens system according to claim 1, characterized in that, The eighth lens has a convex object-side surface in its paraxial region.

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 are arranged sequentially along the optical axis of the imaging lens system from the object side of the imaging lens system toward the imaging surface of the imaging lens system. The second lens has positive refractive power, and The imaging lens system satisfies the following conditional expression: 2.0 <TTL / f4<3.0 Wherein, TTL is the distance along the optical axis from the object side of the first lens to the imaging surface, and f4 is the focal length of the fourth lens.

11. The imaging lens system according to claim 10, characterized in that, The object-side surface of the first lens is convex in its paraxial region.

12. The imaging lens system according to claim 10, characterized in that, The second lens has a concave object-side surface in its paraxial region.

13. The imaging lens system according to claim 10, characterized in that, The fourth lens has a convex object-side surface in its paraxial region.

14. The imaging lens system according to claim 10, characterized in that, The fifth lens has a convex object-side surface in its paraxial region.

15. The imaging lens system according to claim 10, characterized in that, The sixth lens has a convex object-side surface in its paraxial region.

16. The imaging lens system according to claim 10, characterized in that, The sixth lens has a concave object-side surface in its paraxial region.

17. The imaging lens system according to claim 10, characterized in that, The seventh lens has a convex object-side surface in its paraxial region.

18. The imaging lens system according to claim 10, characterized in that, The eighth lens has a convex object-side surface in its paraxial region.

19. 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 are arranged sequentially along the optical axis of the imaging lens system from the object side of the imaging lens system toward the imaging surface of the imaging lens system. The imaging lens system satisfies the following conditional expression: -1.6 <R3 / f4<-0.4 Wherein, R3 is the radius of curvature of the object side of the second lens at the optical axis, and f4 is the focal length of the fourth lens.

20. The imaging lens system according to claim 19, characterized in that, The second lens has positive refractive power.

Images