Imaging lens system and electronic device

Abstract

An imaging lens system includes: a lens group including a plurality of lenses; and an optical path folding member disposed on the image side of the lens group, wherein -1.2 < fR / PL < -0.40, where fR is the focal length of the last lens in the lens group that is closest to the imaging plane, and PL is the distance from the incident surface of the optical path folding member to the exit surface of the optical path folding member.

Description

Technical Field

[0001] [Cross-reference to related applications]

[0002] This application claims priority to Korean Patent Application No. 10-2022-0159542 filed with the Korean Intellectual Property Office on November 24, 2022, and Korean Patent Application No. 10-2023-0036440 filed with the Korean Intellectual Property Office on March 21, 2023, the entire disclosure of which is incorporated herein by reference for all purposes.

[0003] This disclosure relates to a telephoto imaging lens system that can be mounted on a portable electronic device. Prior Technology

[0004] It may not be easy to make a telephoto imaging lens system with a long focal length (telephoto imaging lens system) have a small thickness and size, and therefore the system may be difficult to install in a small terminal. However, the increasing demand for improved functionality and performance of small terminals (e.g., smartphones) is driving the growing need to install telephoto imaging lens systems in small terminals.

[0005] The above information is provided as background information to aid understanding of this disclosure. No determination or assertion is made as to whether any of the above content is suitable as prior art to this disclosure. Summary of the Invention

[0006] This summary is provided to introduce, in a simplified form, a series of concepts further elaborated in the embodiments below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

[0007] In a general case, an imaging lens system includes: a lens group comprising a plurality of lenses; and an optical path folding member disposed on the image side of the lens group, wherein -1.2 < fR / PL < -0.40, where fR is the focal length of the last lens in the lens group that is closest to the imaging plane, and PL is the distance from the incident surface of the optical path folding member to the exit surface of the optical path folding member.

[0008] The condition 0.80 < f / PL < 2.0 can be satisfied, where f is the focal length of the imaging lens system.

[0009] The condition 0.80 < (|fF|+|fR|) / PL < 2.40 can be satisfied, where fF is the focal length of the foremost lens in the lens group that is closest to the object.

[0010] The condition expression 0.40 < fF / PL < 1.0 can be satisfied.

[0011] The condition expression 0.20 < LFS1 / PL < 0.60 can be satisfied, where LFS1 is the radius of curvature of the object-side surface of the foremost lens in the lens group that is closest to the object.

[0012] The condition 0.20 < LRS2 / PL < 0.60 can be satisfied, where LRS2 is the radius of curvature of the image-side surface of the last lens in the lens group that is closest to the imaging plane.

[0013] The condition expression 0.40 < (LFS1+LRS2) / PL < 0.90 can be satisfied.

[0014] The condition expression 0.10 < TLG / PL < 0.40 can be satisfied, where TLG is the distance from the object-side surface of the foremost lens in the lens group that is closest to the object to the image-side surface of the rearmost lens in the lens group that is closest to the imaging plane.

[0015] The condition 1.05 < TTL / f can be satisfied, where TTL is the distance from the object-side surface of the foremost lens in the lens group, which is closest to the object, to the imaging plane.

[0016] An electronic device may include one or more camera modules, wherein at least one of the one or more camera modules may include an imaging lens system.

[0017] In another general example, an imaging lens system includes: a lens group comprising a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially from the object side toward the imaging plane; and an optical path folding member disposed on the image side of the lens group and comprising four or more reflective surfaces.

[0018] The condition expression 0.5 < f1 / PL < 0.9 can be satisfied, where f1 is the focal length of the first lens and PL is the distance from the incident surface of the optical path folding member to the exit surface of the optical path folding member.

[0019] The conditional expression -0.86 < f5 / PL < -0.46 can be satisfied, where f5 is the focal length of the fifth lens.

[0020] The conditional expression -0.40 < (f1+f2) / PL < -0.10 can be satisfied, where f1 is the focal length of the first lens and f2 is the focal length of the second lens.

[0021] The condition 0.60 < (f1+f2+f3) / PL < 1.20 can be satisfied, where f3 is the focal length of the third lens.

[0022] The condition 1.60 < (f1+f2+f3+f4) / PL < 2.60 can be satisfied, where f4 is the focal length of the fourth lens.

[0023] The condition 1.60 < (f1+f2+f3+f4+f5) / PL < 2.0 can be satisfied, where f5 is the focal length of the fifth lens.

[0024] In another general example, an imaging lens system includes: a lens group comprising a first lens, a second lens, a third lens, a fourth lens having positive refractive power, and a fifth lens having negative refractive power arranged sequentially from the object side toward the imaging plane; and an optical path folding member disposed on the image side of the lens group, wherein 0.7 < BFL / TTL, where BFL is the distance from the image-side surface of the fifth lens to the imaging plane, and TTL is the distance from the object-side surface of the first lens to the imaging plane.

[0025] Other features and characteristics will become apparent from reading the following detailed description, drawings and claims. Simple Explanation of the Diagram

[0026] Figure 1 is a configuration diagram of an imaging lens system according to a first exemplary embodiment. Figure 2 shows the aberration curves of the imaging lens system shown in Figure 1. Figure 3 is a configuration diagram of an imaging lens system according to a second exemplary embodiment. Figure 4 shows the aberration curves of the imaging lens system shown in Figure 3. Figure 5 is a configuration diagram of an imaging lens system according to a third exemplary embodiment. Figure 6 shows the aberration curves of the imaging lens system shown in Figure 5. Figure 7 is a configuration diagram of an imaging lens system according to a fourth exemplary embodiment. Figure 8 shows the aberration curves of the imaging lens system shown in Figure 7. Figure 9 is a configuration diagram of an imaging lens system according to a fifth exemplary embodiment. Figure 10 shows the aberration curves of the imaging lens system shown in Figure 9. Figure 11 is a perspective view of an electronic device according to an exemplary embodiment. Throughout all drawings and detailed descriptions, the same reference numbers refer to the same components. Drawings may not be drawn to scale, and for clarity, illustrative purposes, the relative sizes, proportions, and representations of components may be exaggerated. Implementation

[0027] In the following text, although examples of this disclosure will be described in detail with reference to the accompanying drawings, it should be noted that the examples are not limited thereto.

[0028] The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various modifications, refinements, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding this disclosure. For example, the order of operations described herein is merely illustrative and is not intended to limit the reader to it; rather, as will become apparent upon understanding this disclosure, changes may be made, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in this art may be omitted.

[0029] The features described herein may be implemented in various forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided merely to illustrate some of the many possible ways of implementing the methods, apparatus, and / or systems described herein that will become apparent upon understanding this disclosure.

[0030] Throughout the specification, when an element such as a layer, region, or substrate is described as being "on," "connected to," or "coupled to" another element, the element may be directly "on," directly "connected to," or directly "coupled to" the other element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on," "directly connected to," or "directly coupled to" another element, there may be no other elements in between.

[0031] The term "and / or" as used herein includes any combination of any one or more of the related listed items; similarly, "at least one of..." includes any combination of any one or more of the related listed items.

[0032] Although terms such as "first," "second," and "third" may be used in this document to describe various components, parts, areas, layers, or sections, these components, parts, areas, layers, or sections are not limited by these terms. Specifically, these terms are used only to distinguish individual components, parts, areas, layers, or sections. Therefore, without departing from the teaching content of the examples, the first component, part, area, layer, or section mentioned in the examples described herein may also be referred to as the second component, part, area, layer, or section.

[0033] For ease of explanation, spatially relative terms such as "above," "upper," "below," "lower," and similar expressions are used herein to describe the relationship between one element and another shown in the figures. These spatially relative terms are intended to encompass not only the orientation shown in the figures but also different orientations of the device during use or operation. For example, if the device in the figure is rotated, an element described as "above" or "upper" relative to another element will be described as "below" or "lower" relative to that other element. Therefore, depending on the spatial orientation of the device, the term "above" encompasses both upper and lower orientations. The device may also be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative terms used herein will be explained accordingly.

[0034] The terminology used herein is for illustrative purposes only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the articles "a" and "the" are intended to include the plural form as well. The terms "comprises," "includes," and "has" indicate the presence of the stated features, numbers, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, components, elements, and / or combinations thereof.

[0035] Due to manufacturing techniques and / or tolerances, the shapes shown in the drawings may change. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings, but include shape changes that occur during manufacturing.

[0036] In this document, it should be noted that the use of the term "may" (for example, what an instance may include or implement) means that there exists at least one instance that includes or implements this feature, but not all instances are limited to this.

[0037] As will be apparent upon understanding this disclosure, the features of the instances described herein can be combined in various ways. Furthermore, although the instances described herein have multiple configurations, other configurations are also possible, as will be apparent upon understanding this disclosure.

[0038] One or more embodiments disclosed herein may provide a telephoto imaging lens system with a long focal length that can be mounted in a small terminal.

[0039] In the specification, "first lens" indicates the lens closest to the object (or subject). Additionally, the lens number indicates the order in which the lenses are positioned along the optical axis from the object side. For example, "second lens" indicates the second lens positioned from the object side, and "third lens" indicates the third lens positioned from the object side. In the specification, the radius of curvature, thickness, distance TTL from the object-side surface of the first lens to the imaging plane, height ImgHT of the imaging plane, and focal length of the lenses are all expressed in millimeters (mm).

[0040] Each of the following—lens thickness, inter-lens distance, TTL, and angle of incidence—can be a dimension calculated based on the optical axis of the imaging lens system. Furthermore, in the description of lens shape, a convex surface of the lens can indicate that the paraxial region of the corresponding surface is convex, while a concave surface of the lens can indicate that the paraxial region of the corresponding surface is concave. Therefore, although it is stated that one surface of the lens is convex, the edge portion of the lens can also be concave. Similarly, although it is stated that one surface of the lens is concave, the edge portion of the lens can also be convex.

[0041] The imaging lens system described in this article can be installed in portable electronic devices. For example, it can be installed in smartphones (or portable terminals), laptops, augmented reality devices, virtual reality (VR) devices, portable game consoles, etc. However, the scope and examples of use of the imaging lens system described in this article are not limited to the electronic devices mentioned above. For example, the imaging lens system can be applied to electronic devices that may require high-resolution imaging while providing limited installation space.

[0042] The imaging lens system described herein can reduce the external size of the imaging lens system while ensuring a long back focal length (BFL) (or the distance from the image-side surface of the rearmost lens to the imaging plane). For example, the imaging lens system described herein can reduce the external size of the imaging lens system while ensuring the BFL required for implementing a telephoto imaging lens system by using reflective elements. As another example, the imaging lens system described herein can provide an imaging plane of a considerable size for implementing high resolution. Still as an example, the imaging lens system described herein can have an integrated form that can be mounted in a portable terminal while ensuring a long focal length or long BFL.

[0043] In this specification, "optical path folding component" can refer to any component that allows light to be reflected. For example, "optical path folding component" can be collectively referred to as all reflectors, prisms, etc. Therefore, in this specification, "reflector," "prism," and "optical path folding component" can all refer to the same component or interchangeable components.

[0044] The imaging lens system according to the first aspect of this disclosure may include a lens group and an optical path folding member. In the imaging lens system according to the first aspect, the lens group may include multiple lenses. For example, the lens group may include a first lens, a second lens, a third lens, and a fourth lens arranged sequentially from the object side. As another example, the lens group may include a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially from the object side. However, the number of lenses included in the lens group is not limited to four or five lenses. In the imaging lens system according to the first aspect, the optical path folding member may have a considerable distance (PL) from the incident surface to the exit surface. For example, the PL of the optical path folding member may have a unique relationship with the focal length fR of the last lens (or the lens in the lens group closest to the imaging plane). As a specific example, the imaging lens system according to the first aspect may satisfy the following conditional expression: -1.2 < fR / PL < -0.4.

[0045] An imaging lens system according to a second aspect of this disclosure may include a lens group and an optical path folding member. In the imaging lens system according to the second aspect, the lens group may include multiple lenses. For example, the lens group may include a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially from the object side. In the imaging lens system according to the second aspect, the optical path folding member may include multiple reflective surfaces. For example, the optical path folding member may include four or more reflective surfaces. As a specific example, the optical path folding member may include a first reflective surface, a second reflective surface, a third reflective surface, and a fourth reflective surface. The optical path folding member may include two total internal reflection surfaces and two or more regular reflective surfaces (or specular reflective surfaces). For example, in the optical path folding member, the first and fourth reflective surfaces may be total internal reflection surfaces, while the second and third reflective surfaces may be regular reflective surfaces.

[0046] An imaging lens system according to a third aspect of this disclosure may include a lens group and an optical path folding member. In the imaging lens system according to the third aspect, the lens group may include multiple lenses. For example, the lens group may include a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially from the object side. In the imaging lens system according to the third aspect, the optical path folding member may include multiple reflective surfaces. For example, the optical path folding member may include four or more reflective surfaces. As a specific example, the optical path folding member may include a first reflective surface, a second reflective surface, a third reflective surface, and a fourth reflective surface. The optical path folding member may include an incident surface and an exit surface. The incident surface may be disposed closest to the lens group, while the exit surface may be disposed closest to the imaging plane. The optical path folding member may have an incident surface and a reflective surface integrally formed with each other. For example, the incident surface and the second reflective surface may be the same surface in the optical path folding member.

[0047] An imaging lens system according to the fourth aspect of this disclosure may include a lens group and an optical path folding member. In the imaging lens system according to the fourth aspect, the lens group may include multiple lenses. For example, the lens group may include a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially from the object side. In the imaging lens system according to the fourth aspect, the optical path folding member may include multiple reflective surfaces. For example, the optical path folding member may include four or more reflective surfaces. As a specific example, the optical path folding member may include a first reflective surface, a second reflective surface, a third reflective surface, and a fourth reflective surface. In the imaging lens system according to the fourth aspect, the reflective surfaces of the optical path folding member may have unique geometric relationships. For example, the angle between the first reflective surface and the second reflective surface may be 15 degrees to 30 degrees. As another example, the angle between the third reflective surface and the fourth reflective surface may be 15 degrees to 30 degrees.

[0048] An imaging lens system according to a fifth aspect of this disclosure may include a lens group and an optical path folding member. In the imaging lens system according to the fifth aspect, the lens group may include multiple lenses. For example, the lens group may include a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially from the object side. In the imaging lens system according to the fifth aspect, the optical path folding member may include multiple reflective surfaces. For example, the optical path folding member may include six or more reflective surfaces. As a specific example, the optical path folding member may include a first reflective surface, a second reflective surface, a third reflective surface, a fourth reflective surface, a fifth reflective surface, and a sixth reflective surface. The optical path folding member may include an incident surface and an exit surface. The incident surface may be disposed closest to the lens group, while the exit surface may be disposed closest to the imaging plane. The optical path folding member may have an incident surface and a reflective surface integrally formed with each other. For example, the incident surface, the second reflective surface, and the fourth reflective surface may be the same surface in the optical path folding member. As another example, the exit surface, the third reflective surface, and the fifth reflective surface may be the same surface in the optical path folding member.

[0049] The imaging lens system of the sixth state according to this disclosure can satisfy one or more of the following conditional expressions. However, not only the imaging lens system of the sixth state can satisfy the following conditional expressions. For example, the imaging lens systems of the first to fifth states described above can also satisfy one or more of the following conditional expressions: 0.7 < BFL / TTL 25 < V1-V2 10 mm < f 1.05 < TTL / f.

[0050] In the above conditional expressions, BFL is the distance from the image-side surface of the last lens in the lens group to the imaging plane, TTL is the distance from the object-side surface of the foremost lens (first lens) in the lens group to the imaging plane, V1 is the Abbe number of the first lens, V2 is the Abbe number of the second lens (the lens closest to the first lens on the image side), and f is the focal length of the imaging lens system.

[0051] The imaging lens system according to this disclosure can satisfy the above-described conditional expression in a more limited form as follows: 0.7 < BFL / TTL < 0.9 25 < V1-V2 < 32 12 mm < f < 26 mm 1.05 < TTL / f < 1.4.

[0052] The imaging lens system according to this disclosure can satisfy the above-described conditional expression in a more limited form as follows: 1.2 < TTL / f < 1.4.

[0053] The imaging lens system of the seventh state according to this disclosure can satisfy one or more of the following conditional expressions. However, the imaging lens system of the seventh state can satisfy not only the following conditional expressions. For example, the imaging lens systems of the first to sixth states described above can also satisfy one or more of the following conditional expressions: 0.80 < f / PL < 2.0 0.80 < (|fF|+|fR|) / PL < 2.40 0.40 < fF / PL < 1.0 -1.20 < fR / PL < -0.40 0.20 < LFS1 / PL < 0.60 0.20 < LRS2 / PL < 0.60 0.40 < (LFS1+LRS2) / PL < 0.90 0.10 < TLG / PL < 0.4 0.06 < ImgHT / PL < 0.20 1.20 < (TTL + ImgHT) / PL < 2.40 2.10 < (TTL+f) / PL < 4.10.

[0054] In the above conditional expressions, PL is the distance from the incident surface to the exit surface of the optical path folding member, fF is the focal length of the foremost lens in the lens group that is closest to the object, fR is the focal length of the last lens in the lens group that is closest to the imaging plane, LFS1 is the radius of curvature of the object-side surface of the foremost lens, LRS2 is the radius of curvature of the image-side surface of the last lens, TLG is the distance from the object-side surface of the foremost lens to the image-side surface of the last lens, and ImgHT is the height of the imaging plane.

[0055] The imaging lens system of the eighth state according to this disclosure can satisfy one or more of the following conditional expressions. However, not only the imaging lens system of the eighth state can satisfy the following conditional expressions. For example, the imaging lens systems of the first to seventh states described above can also satisfy one or more of the following conditional expressions: 0.50 < f1 / PL < 0.9 -0.86 < f5 / PL < -0.46 -0.40 < (f1+f2) / PL < -0.10 0.60 < (f1+f2+f3) / PL < 1.20 1.60 < (f1+f2+f3+f4) / PL < 2.60 1.0 < (f1+f2+f3+f4+f5) / PL < 2.0 0.24 < R1 / PL < 0.48 0.24 < R10 / PL < 0.48 0.52 < (R1+R10) / PL < 0.96 0.19 < TLG / PL < 0.38 0.09 < ImgHT / PL < 0.19 1.52 < (TTL+ImgHT) / PL < 2.32.

[0056] 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, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, R1 is the radius of curvature of the object-side surface of the first lens, and R10 is the radius of curvature of the image-side surface of the fifth lens.

[0057] If necessary, the imaging lens system according to the first to eighth states may include one or more lenses having the following characteristics. For example, the imaging lens system according to the first state may include one of the first to fifth lenses having the following characteristics. As another example, the imaging lens system according to the second state may include two or more of the first to fifth lenses having the following characteristics. However, the imaging lens system according to the states described above may not necessarily include lenses having the following characteristics.

[0058] The first lens may have refractive power. For example, the first lens may have positive refractive power. The first lens may have a convex surface. For example, the first lens may have a convex object-side surface. The first lens may have a predetermined refractive index. For example, the refractive index of the first lens may be 1.5 or greater than 1.5. As a specific example, the refractive index of the first lens may be greater than 1.5 and less than 1.6. The first lens may have a predetermined Abbe number. For example, the Abbe number of the first lens may be 50 or greater than 50. As a specific example, the Abbe number of the first lens may be greater than 52 and less than 62. The first lens may have a predetermined focal length. For example, the focal length of the first lens may be determined in the range of 7.0 mm to 14.0 mm.

[0059] The second lens may have refractive power. For example, the second lens may have positive or negative refractive power. The second lens may have a concave surface. For example, the object-side surface of the second lens may have a concave shape. The second lens may have a predetermined refractive index. For example, the refractive index of the second lens may be 1.6 or greater than 1.6. As a specific example, the refractive index of the second lens may be greater than 1.6 and less than 1.7. The second lens may have a predetermined Abbe number. For example, the Abbe number of the second lens may be 20 or greater than 20. As a specific example, the Abbe number of the second lens may be greater than 20 and less than 30. The second lens may have a predetermined focal length. For example, the focal length of the second lens may be determined in the range of -16.0 mm to -8.0 mm. As another example, the focal length of the second lens may be greater than 130 mm.

[0060] The third lens may have refractive power. For example, the third lens may have positive refractive power. The third lens may have a convex surface. For example, the third lens may have a convex object-side surface. The third lens may have a predetermined refractive index. For example, the refractive index of the third lens may be 1.6 or greater than 1.6. As a specific example, the refractive index of the third lens may be greater than 1.64 and less than 1.70. The third lens may have a predetermined Abbe number. For example, the Abbe number of the third lens may be 18 or greater than 18. As a specific example, the Abbe number of the third lens may be greater than 18 and less than 30. The third lens may have a predetermined focal length. For example, the focal length of the third lens may be determined in the range of 10 mm to 20 mm. As another example, the focal length of the third lens may be 40 mm or greater than 40 mm.

[0061] The fourth lens may have refractive power. For example, the fourth lens may have positive or negative refractive power. The fourth lens may have a convex surface. For example, the fourth lens may have a convex image-side surface. The fourth lens may have a predetermined refractive index. For example, the refractive index of the fourth lens may be 1.5 or greater than 1.5. As a specific example, the refractive index of the fourth lens may be greater than 1.5 and less than 1.6. The fourth lens may have a predetermined Abbe number. For example, the Abbe number of the fourth lens may be 50 or greater than 50. As a specific example, the Abbe number of the fourth lens may be greater than 50 and less than 60. The fourth lens may have a predetermined focal length. For example, the focal length of the fourth lens may be determined in the range of 10 mm to 24 mm. As another example, the focal length of the fourth lens may be determined in the range of -12 mm to -8.0 mm.

[0062] The fifth lens may have refractive power. For example, the fifth lens may have negative refractive power. The fifth lens may have a concave surface. For example, the fifth lens may have a concave image-side surface. The fifth lens may have a predetermined refractive index. For example, the refractive index of the fifth lens may be 1.6 or greater than 1.6. As a specific example, the refractive index of the fifth lens may be greater than 1.6 and less than 1.7. The fifth lens may have a predetermined Abbe number. For example, the Abbe number of the fifth lens may be 20 or greater than 20. As a specific example, the Abbe number of the fifth lens may be greater than 24 and less than 32. The fifth lens may have a predetermined focal length. For example, the focal length of the fifth lens may be determined in the range of -12.0 mm to -5.0 mm.

[0063] The aspherical surfaces of the first to fifth lenses can be represented by the following Equation 1. In Equation 1, c is the reciprocal of the radius of curvature of the corresponding lens, k is the conic constant, r is the distance from any point on the aspherical surface of the lens to the optical axis, A to H and J indicate the aspherical constants, and Z (or sag (SAG)) is the height from any point on the aspherical surface to the vertex of the aspherical surface in the direction of the optical axis.

[0064] Equation 1

[0065] The electronic device according to the first aspect of this disclosure can be thinned for easy portability or storage. For example, the electronic device according to the first aspect may be a smartphone, a laptop, etc. The electronic device according to the first aspect may include a camera module with a long focal length and capable of implementing high resolution. For example, the electronic device may be equipped with a camera module including one of the imaging lens systems according to the first to eighth aspects described above. However, the imaging lens system included in the camera module is not limited to the imaging lens systems according to the first to eighth aspects described above.

[0066] In the following, exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.

[0067] First, this disclosure describes an imaging lens system according to a first exemplary embodiment with reference to FIG1.

[0068] The imaging lens system 100 according to this exemplary embodiment may include a lens group LG and a prism P as a type of optical path folding member. However, the components of the imaging lens system 100 are not limited to those mentioned above. For example, the imaging lens system 100 may further include a filter IF and an imaging plane IP. The lens group LG and the prism P may be arranged sequentially from the object side. For example, the lens group LG may be disposed on the object side of the prism P, and the prism P may be disposed between the lens group LG and the imaging plane IP.

[0069] Next, we will describe examples of the components mentioned above.

[0070] A lens group LG may include multiple lenses. For example, the lens group LG may include a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, and a fifth lens 150 arranged sequentially from the object side. The first lens 110 to the fifth lens 150 may be arranged at predetermined intervals. For example, the image-side surface of the first lens 110 may not be in contact with the object-side surface of the second lens 120, and the image-side surface of the second lens 120 may not be in contact with the object-side surface of the third lens 130. However, the first lens 110 to the fifth lens 150 need not be arranged so that they do not contact each other. For example, the image-side surface of the first lens 110 may be in contact with the object-side surface of the second lens 120, and the image-side surface of the second lens 120 may be in contact with the object-side surface of the third lens 130.

[0071] Next, the characteristics of the first lens 110 to the fifth lens 150 will be described with reference to one or more exemplary embodiments of this disclosure.

[0072] The first lens 110 may have positive refractive power. The first lens 110 may have a convex object-side surface and a concave image-side surface. The second lens 120 may have negative refractive power. The second lens 120 may have a concave object-side surface and a concave image-side surface. The third lens 130 may have positive refractive power. The third lens 130 may have a convex object-side surface and a convex image-side surface. The fourth lens 140 may have positive refractive power. The fourth lens 140 may have a convex object-side surface and a convex image-side surface. The fifth lens 150 may have negative refractive power. The fifth lens 150 may have a convex object-side surface and a concave image-side surface.

[0073] Next, this disclosure describes one or more examples of a prism P that can serve as an optical path folding member. For reference, the prism described below is an example of one type of optical path folding member described herein and can be modified into another type of optical path folding member.

[0074] The prism P may include multiple surfaces. For example, the prism P may include a first surface PS1, a second surface PS2, a third surface PS3, and a fourth surface PS4. The first surface PS1 to the fourth surface PS4 may be sequentially connected to each other to form a small facet.

[0075] A prism P may include an incident surface, four reflecting surfaces, and an exiting surface. For example, the first surface PS1 of the prism P may be the incident surface and the second reflecting surface, the second surface PS2 of the prism P may be the first reflecting surface, the third surface PS3 of the prism P may be the third reflecting surface and the exiting surface, and the fourth surface PS4 of the prism P may be the fourth reflecting surface.

[0076] The first surface PS1 of prism P can receive light emitted from the lens group LG. For example, a portion of the first surface PS1 of prism P can face the rearmost lens in the lens group LG. The first surface PS1 of prism P can reflect light. For example, a portion of the first surface PS1 of prism P can reflect light reflected from the second surface PS2.

[0077] The second surface PS2 of the prism P can reflect light incident through the first surface PS1. For example, the second surface PS2 of the prism P can reflect light incident through a portion of the first surface PS1 to another portion of the first surface PS1.

[0078] The third surface PS3 of the prism P can reflect and emit light. For example, a portion of the third surface PS3 of the prism P can reflect light reflected from the first surface PS1 to the fourth surface PS4, while another portion of the third surface PS3 of the prism P can emit light reflected from the fourth surface PS4 to the imaging plane IP.

[0079] The fourth surface PS4 of prism P can reflect light reflected from the third surface PS3. For example, the fourth surface PS4 of prism P can reflect light reflected from a portion of the third surface PS3 to another portion of the third surface PS3.

[0080] Prism P can achieve both total internal reflection and regular internal reflection. For example, the second surface PS2 and the fourth surface PS4 of prism P can achieve total internal reflection, while the first surface PS1 and the third surface PS3 of prism P can achieve regular internal reflection or specular reflection. For example, the angle of incidence of the first surface PS1 and the third surface PS3 can be greater than the angle of incidence of the second surface PS2 and the fourth surface PS4. As another example, the angle of incidence of the first surface PS1 and the third surface PS3 can be greater than the critical angle of the corresponding surface, while the angle of incidence of the second surface PS2 and the fourth surface PS4 can be less than the critical angle of the corresponding surface.

[0081] The first surface PS1, second surface PS2, third surface PS3, and fourth surface PS4 of the prism P may have predetermined angles. For example, the first surface PS1 and the second surface PS2 may have acute angles. As a specific example, the angle between the first surface PS1 and the second surface PS2 may be 26 degrees to 34 degrees. As another example, the first surface PS1 and the fourth surface PS4 may have obtuse angles. As a specific example, the angle between the first surface PS1 and the fourth surface PS4 may be 146 degrees to 154 degrees. As yet another example, the second surface PS2 and the third surface PS3 may have obtuse angles. As a specific example, the angle between the second surface PS2 and the third surface PS3 may be 146 degrees to 154 degrees. As yet another example, the third surface PS3 and the fourth surface PS4 may have acute angles. As a specific example, the angle between the third surface PS3 and the fourth surface PS4 may be 26 degrees to 34 degrees.

[0082] The filter IF and the imaging plane IP can be positioned adjacent to the exit surface of the prism P.

[0083] A filter IF can block light of a specific wavelength. For example, the filter IF according to this exemplary embodiment can block infrared light. However, the types of light blocked by the filter IF are not limited to infrared light. For example, the filter IF can block ultraviolet light or visible light.

[0084] The imaging plane IP can be located at the point where the light reflected from the fourth reflective surface PS4 of the prism P converges or forms an image, and can be formed by an image sensor IS, etc. For example, the imaging plane IP can be formed on or within the image sensor IS.

[0085] The imaging lens system 100 configured as described above can exhibit the aberration characteristics shown in Figure 2. Tables 1 and 2 respectively show the lens characteristics and aspherical values ​​of the imaging lens system according to this exemplary embodiment.

[0086] Table 1 Surface number Components radius of curvature Thickness / Distance Refractive index Abbe number S1 First lens 3.97648 0.812 1.537 55.7 S2 162.059 0.277 S3 Second lens -32.579 0.222 1.621 26.0 S4 7.393 0.289 S5 Third lens 8.066 0.300 1.679 19.2 S6 -360.182 0.100 S7 Fourth lens 10.124 0.313 1.537 55.7 S8 -36.1606 0.090 S9 Fifth lens 27.0447 0.300 1.621 26.0 S10 3.77351 0.500 S11 Prism infinity 1.500 1.519 64.2 S12 infinity 3.000 1.519 64.2 S13 infinity 5.500 1.519 64.2 S14 infinity 3.500 1.519 64.2 S15 infinity 0.210 1.519 64.2 S16 infinity 0.500 S17 Filter infinity 0.210 1.519 64.2 S18 infinity 1.073 S19 Imaging plane infinity 0.041

[0087] Table 2 Surface number S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 K 0 0 0 0 0 0 -1.438E+01 0 0 5.848E-01 A 0 0 0 0 0 0 1.153E-02 0 0 -4.057E-03 B 0 0 0 0 0 0 2.594E-03 0 0 -7.373E-03 C 0 0 0 0 0 0 -1.417E-03 0 0 4.772E-03 D 0 0 0 0 0 0 0 0 0 2.042E-03 E 0 0 0 0 0 0 0 0 0 0 F 0 0 0 0 0 0 0 0 0 0 G 0 0 0 0 0 0 0 0 0 0 H 0 0 0 0 0 0 0 0 0 0 J 0 0 0 0 0 0 0 0 0 0

[0088] This disclosure will now describe an imaging lens system according to a second exemplary embodiment with reference to FIG3.

[0089] The imaging lens system 200 according to this exemplary embodiment may include a lens group LG and a prism P as a type of optical path folding member. However, the components of the imaging lens system 200 are not limited to those mentioned above. For example, the imaging lens system 200 may further include a filter IF and an imaging plane IP. The lens group LG and the prism P may be arranged sequentially from the object side. For example, the lens group LG may be disposed on the object side of the prism P, and the prism P may be disposed between the lens group LG and the imaging plane IP.

[0090] Next, we will describe examples of the components mentioned above.

[0091] The lens group LG may include multiple lenses. For example, the lens group LG may include a first lens 210, a second lens 220, a third lens 230, a fourth lens 240, and a fifth lens 250 arranged sequentially from the object side. The first lens 210 to the fifth lens 250 may be arranged at predetermined intervals. For example, the image-side surface of the first lens 210 may not be in contact with the object-side surface of the second lens 220, and the image-side surface of the second lens 220 may not be in contact with the object-side surface of the third lens 230. However, the first lens 210 to the fifth lens 250 need not be arranged so that they do not contact each other. For example, the image-side surface of the first lens 210 may be in contact with the object-side surface of the second lens 220, and the image-side surface of the second lens 220 may be in contact with the object-side surface of the third lens 230.

[0092] Next, the characteristics of the first lens 210 to the fifth lens 250 will be described with reference to one or more exemplary embodiments of this disclosure.

[0093] The first lens 210 may have positive refractive power. The first lens 210 may have a convex object-side surface and a concave image-side surface. The second lens 220 may have negative refractive power. The second lens 220 may have a concave object-side surface and a concave image-side surface. The third lens 230 may have positive refractive power. The third lens 230 may have a convex object-side surface and a convex image-side surface. The fourth lens 240 may have positive refractive power. The fourth lens 240 may have a convex object-side surface and a convex image-side surface. The fifth lens 250 may have negative refractive power. The fifth lens 250 may have a convex object-side surface and a concave image-side surface.

[0094] Next, this disclosure describes one or more examples of a prism P that can serve as an optical path folding member. For reference, the prism described below is an example of one type of optical path folding member described herein and can be modified into another type of optical path folding member.

[0095] The prism P may include multiple surfaces. For example, the prism P may include a first surface PS1, a second surface PS2, a third surface PS3, and a fourth surface PS4. The first surface PS1 to the fourth surface PS4 may be sequentially connected to each other to form a small facet.

[0096] A prism P may include an incident surface, four reflecting surfaces, and an exiting surface. For example, the first surface PS1 of the prism P may be the incident surface and the second reflecting surface, the second surface PS2 of the prism P may be the first reflecting surface, the third surface PS3 of the prism P may be the third reflecting surface and the exiting surface, and the fourth surface PS4 of the prism P may be the fourth reflecting surface.

[0097] The first surface PS1 of prism P can receive light emitted from the lens group LG. For example, a portion of the first surface PS1 of prism P can face the rearmost lens in the lens group LG. The first surface PS1 of prism P can reflect light. For example, a portion of the first surface PS1 of prism P can reflect light reflected from the second surface PS2.

[0098] The second surface PS2 of the prism P can reflect light incident through the first surface PS1. For example, the second surface PS2 of the prism P can reflect light incident through a portion of the first surface PS1 to another portion of the first surface PS1.

[0099] The third surface PS3 of the prism P can reflect and emit light. For example, a portion of the third surface PS3 of the prism P can reflect light reflected from the first surface PS1 to the fourth surface PS4, while another portion of the third surface PS3 of the prism P can emit light reflected from the fourth surface PS4 to the imaging plane IP.

[0100] The fourth surface PS4 of prism P can reflect light reflected from the third surface PS3. For example, the fourth surface PS4 of prism P can reflect light reflected from a portion of the third surface PS3 to another portion of the third surface PS3.

[0101] Prism P can achieve both total internal reflection and regular internal reflection. For example, the second surface PS2 and the fourth surface PS4 of prism P can achieve total internal reflection, while the first surface PS1 and the third surface PS3 of prism P can achieve regular internal reflection or specular reflection. For example, the angle of incidence of the first surface PS1 and the third surface PS3 can be greater than the angle of incidence of the second surface PS2 and the fourth surface PS4. As another example, the angle of incidence of the first surface PS1 and the third surface PS3 can be greater than the critical angle of the corresponding surface, while the angle of incidence of the second surface PS2 and the fourth surface PS4 can be less than the critical angle of the corresponding surface.

[0102] The first surface PS1, the second surface PS2, the third surface PS3, and the fourth surface PS4 of the prism P can form predetermined angles. For example, the first surface PS1 and the second surface PS2 can have an acute angle. As a specific example, the angle between the first surface PS1 and the second surface PS2 can be 26 degrees to 34 degrees. As another example, the first surface PS1 and the fourth surface PS4 can have an obtuse angle. As a specific example, the angle between the first surface PS1 and the fourth surface PS4 can be 146 degrees to 154 degrees. As yet another example, the second surface PS2 and the third surface PS3 can have an obtuse angle. As a specific example, the angle between the second surface PS2 and the third surface PS3 can be 146 degrees to 154 degrees. As yet another example, the third surface PS3 and the fourth surface PS4 can have an acute angle. As a specific example, the angle between the third surface PS3 and the fourth surface PS4 can be 26 degrees to 34 degrees.

[0103] The filter IF and the imaging plane IP can be positioned adjacent to the exit surface of the prism P.

[0104] A filter IF can block light of a specific wavelength. For example, the filter IF according to this exemplary embodiment can block infrared light. However, the types of light blocked by the filter IF are not limited to infrared light. For example, the filter IF can block ultraviolet light or visible light.

[0105] The imaging plane IP can be located at the point where the light reflected from the fourth reflective surface PS4 of the prism P converges or forms an image, and can be formed by an image sensor IS, etc. For example, the imaging plane IP can be formed on or within the image sensor IS.

[0106] The imaging lens system 200 configured as described above can be illustrated with the aberration characteristics shown in Figure 4. Tables 3 and 4 respectively show the lens characteristics and aspherical values ​​of the imaging lens system according to this exemplary embodiment.

[0107] Table 3 Surface number Components radius of curvature Thickness / Distance Refractive index Abbe number S1 First lens 3.94238 0.875 1.537 55.7 S2 349.800 0.292 S3 Second lens -24.564 0.298 1.621 26.0 S4 8.285 0.335 S5 Third lens 8.727 0.300 1.679 19.2 S6 -386.721 0.100 S7 Fourth lens 10.037 0.654 1.537 55.7 S8 -20.5465 0.090 S9 Fifth lens 28.5194 0.300 1.621 26.0 S10 3.51177 0.500 S11 Prism infinity 1.600 1.519 64.2 S12 infinity 2.500 1.519 64.2 S13 infinity 4.000 1.519 64.2 S14 infinity 2.800 1.519 64.2 S15 infinity 0.334 1.519 64.2 S16 infinity 0.500 S17 Filter infinity 0.210 1.519 64.2 S18 infinity 1.188 S19 Imaging plane infinity 0.001

[0108] Table 4 Surface number S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 K 0 0 0 0 0 0 -1.420E+01 0 0 5.697E-01 A 0 0 0 0 0 0 1.104E-02 0 0 -4.340E-03 B 0 0 0 0 0 0 2.123E-03 0 0 -7.661E-03 C 0 0 0 0 0 0 -1.363E-03 0 0 4.859E-03 D 0 0 0 0 0 0 2.927E-04 0 0 1.924E-03 E 0 0 0 0 0 0 0 0 0 0 F 0 0 0 0 0 0 0 0 0 0 G 0 0 0 0 0 0 0 0 0 0 H 0 0 0 0 0 0 0 0 0 0 J 0 0 0 0 0 0 0 0 0 0

[0109] The present disclosure will now be described with reference to FIG5, an imaging lens system according to a third exemplary embodiment.

[0110] The imaging lens system 300 according to this exemplary embodiment may include a lens group LG and a prism P as a type of optical path folding member. However, the components of the imaging lens system 300 are not limited to those mentioned above. For example, the imaging lens system 300 may further include a filter IF and an imaging plane IP. The lens group LG and the prism P may be arranged sequentially from the object side. For example, the lens group LG may be disposed on the object side of the prism P, and the prism P may be disposed between the lens group LG and the imaging plane IP.

[0111] Next, we will describe examples of the components mentioned above.

[0112] The lens group LG may include multiple lenses. For example, the lens group LG may include a first lens 310, a second lens 320, a third lens 330, a fourth lens 340, and a fifth lens 350 arranged sequentially from the object side. The first lens 310 to the fifth lens 350 may be arranged at predetermined intervals. For example, the image-side surface of the first lens 310 may not be in contact with the object-side surface of the second lens 320, and the image-side surface of the second lens 320 may not be in contact with the object-side surface of the third lens 330. However, the first lens 310 to the fifth lens 350 need not be arranged so that they do not contact each other. For example, the image-side surface of the first lens 310 may be in contact with the object-side surface of the second lens 320, and the image-side surface of the second lens 320 may be in contact with the object-side surface of the third lens 330.

[0113] The characteristics of the first lens 310 to the fifth lens 350 will be described next based on one or more exemplary embodiments of this disclosure.

[0114] The first lens 310 may have positive refractive power. The first lens 310 may have a convex object-side surface and a concave image-side surface. The second lens 320 may have negative refractive power. The second lens 320 may have a concave object-side surface and a concave image-side surface. The third lens 330 may have positive refractive power. The third lens 330 may have a convex object-side surface and a convex image-side surface. The fourth lens 340 may have positive refractive power. The fourth lens 340 may have a convex object-side surface and a convex image-side surface. The fifth lens 350 may have negative refractive power. The fifth lens 350 may have a convex object-side surface and a concave image-side surface.

[0115] Next, this disclosure describes one or more examples of a prism P that can serve as an optical path folding member. For reference, the prism described below is an example of one type of optical path folding member described herein and can be modified into another type of optical path folding member.

[0116] The prism P may include multiple surfaces. For example, the prism P may include a first surface PS1, a second surface PS2, a third surface PS3, and a fourth surface PS4. The first surface PS1 to the fourth surface PS4 may be sequentially connected to each other to form a small facet.

[0117] A prism P may include an incident surface, six reflecting surfaces, and an exiting surface. For example, the first surface PS1 of the prism P may be the incident surface and may also be the second and fourth reflecting surfaces; the second surface PS2 of the prism P may be the first reflecting surface; the third surface PS3 of the prism P may be the third reflecting surface and may also be the fifth reflecting surface and the exiting surface; and the fourth surface PS4 of the prism P may be the sixth reflecting surface.

[0118] The first surface PS1 of prism P can receive light emitted from the lens group LG. For example, a portion of the first surface PS1 of prism P can face the rearmost lens in the lens group LG. The first surface PS1 of prism P can reflect light. For example, a portion of the first surface PS1 of prism P can reflect light reflected from the second surface PS2. Additionally, another portion of the first surface PS1 of prism P can reflect light reflected from the third surface PS3.

[0119] The second surface PS2 of the prism P can reflect light incident through the first surface PS1. For example, the second surface PS2 of the prism P can reflect light incident through a portion of the first surface PS1 to another portion of the first surface PS1.

[0120] The third surface PS3 of the prism P can reflect and emit light. For example, a portion of the third surface PS3 of the prism P can reflect light reflected from the first surface PS1 to the fourth surface PS4, while another portion of the third surface PS3 of the prism P can emit light reflected from the fourth surface PS4 to the imaging plane IP.

[0121] The fourth surface PS4 of prism P can reflect light reflected from the third surface PS3. For example, the fourth surface PS4 of prism P can reflect light reflected from a portion of the third surface PS3 to another portion of the third surface PS3.

[0122] Prism P can achieve both total internal reflection and regular internal reflection. For example, the second surface PS2 and the fourth surface PS4 of prism P can achieve total internal reflection, while the first surface PS1 and the third surface PS3 of prism P can achieve regular internal reflection or specular reflection. For example, the angle of incidence of the first surface PS1 and the third surface PS3 can be greater than the angle of incidence of the second surface PS2 and the fourth surface PS4. As another example, the angle of incidence of the first surface PS1 and the third surface PS3 can be greater than the critical angle of the corresponding surface, while the angle of incidence of the second surface PS2 and the fourth surface PS4 can be less than the critical angle of the corresponding surface.

[0123] The first surface PS1, the second surface PS2, the third surface PS3, and the fourth surface PS4 of the prism P can form predetermined angles. For example, the first surface PS1 and the second surface PS2 can have an acute angle. As a specific example, the angle between the first surface PS1 and the second surface PS2 can be 26 degrees to 34 degrees. As another example, the first surface PS1 and the fourth surface PS4 can have an obtuse angle. As a specific example, the angle between the first surface PS1 and the fourth surface PS4 can be 146 degrees to 154 degrees. As yet another example, the second surface PS2 and the third surface PS3 can have an obtuse angle. As a specific example, the angle between the second surface PS2 and the third surface PS3 can be 146 degrees to 154 degrees. As yet another example, the third surface PS3 and the fourth surface PS4 can have an acute angle. As a specific example, the angle between the third surface PS3 and the fourth surface PS4 can be 26 degrees to 34 degrees.

[0124] The filter IF and the imaging plane IP can be positioned adjacent to the exit surface of the prism P.

[0125] A filter IF can block light of a specific wavelength. For example, the filter IF according to this exemplary embodiment can block infrared light. However, the types of light blocked by the filter IF are not limited to infrared light. For example, the filter IF can block ultraviolet light or visible light.

[0126] The imaging plane IP can be located at the point where the light reflected from the fourth reflective surface PS4 of the prism P converges or forms an image, and can be formed by an image sensor IS, etc. For example, the imaging plane IP can be formed on or within the image sensor IS.

[0127] The imaging lens system 300 configured as described above can be illustrated with the aberration characteristics shown in Figure 6. Tables 5 and 6 respectively show the lens characteristics and aspherical values ​​of the imaging lens system according to this exemplary embodiment.

[0128] Table 5 Surface number Components radius of curvature Thickness / Distance Refractive index Abbe number S1 First lens 3.99514 0.932 1.537 55.7 S2 435.155 0.182 S3 Second lens -34.370 0.220 1.621 26.0 S4 6.889 0.230 S5 Third lens 7.839 0.300 1.679 19.2 S6 -285.403 0.100 S7 Fourth lens 10.311 0.310 1.537 55.7 S8 -106.374 0.090 S9 Fifth lens 19.4246 0.300 1.621 26.0 S10 3.68013 0.500 S11 Prism infinity 1.800 1.519 64.2 S12 infinity 2.300 1.519 64.2 S13 infinity 3.000 1.519 64.2 S14 infinity 3.000 1.519 64.2 S15 infinity 1.888 1.519 64.2 S16 infinity 2.300 1.519 64.2 S17 infinity 1.800 1.519 64.2 S18 infinity 0.300 S19 Filter infinity 0.210 1.519 64.2 S20 infinity 0.885 S21 Imaging plane infinity 0.181

[0129] Table 6 Surface number S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 K 0 0 0 0 0 0 -1.414E+01 0 0 5.805E-01 A 0 0 0 0 0 0 1.255E-02 0 0 -4.177E-03 B 0 0 0 0 0 0 2.459E-03 0 0 -7.802E-03 C 0 0 0 0 0 0 -9.462E-04 0 0 4.997E-03 D 0 0 0 0 0 0 -2.844E-04 0 0 1.960E-03 E 0 0 0 0 0 0 0 0 0 0 F 0 0 0 0 0 0 0 0 0 0 G 0 0 0 0 0 0 0 0 0 0 H 0 0 0 0 0 0 0 0 0 0 J 0 0 0 0 0 0 0 0 0 0

[0130] This disclosure will now describe an imaging lens system according to a fourth exemplary embodiment with reference to FIG7.

[0131] The imaging lens system 400 according to this exemplary embodiment may include a lens group LG and a prism P as a type of optical path folding member. However, the components of the imaging lens system 400 are not limited to those mentioned above. For example, the imaging lens system 400 may further include a filter IF and an imaging plane IP. The lens group LG and the prism P may be arranged sequentially from the object side. For example, the lens group LG may be disposed on the object side of the prism P, and the prism P may be disposed between the lens group LG and the imaging plane IP.

[0132] Next, we will describe examples of the components mentioned above.

[0133] A lens group LG may include multiple lenses. For example, the lens group LG may include a first lens 410, a second lens 420, a third lens 430, a fourth lens 440, and a fifth lens 450 arranged sequentially from the object side. The first lens 410 to the fifth lens 450 may be arranged at predetermined intervals. For example, the image-side surface of the first lens 410 may not be in contact with the object-side surface of the second lens 420, and the image-side surface of the second lens 420 may not be in contact with the object-side surface of the third lens 430. However, the first lens 410 to the fifth lens 450 need not be arranged so that they do not contact each other. For example, the image-side surface of the first lens 410 may be in contact with the object-side surface of the second lens 420, and the image-side surface of the second lens 420 may be in contact with the object-side surface of the third lens 430.

[0134] Next, the characteristics of the first lens 410 to the fifth lens 450 will be described with reference to one or more exemplary embodiments of this disclosure.

[0135] The first lens 410 may have positive refractive power. The first lens 410 may have a convex object-side surface and a concave image-side surface. The second lens 420 may have negative refractive power. The second lens 420 may have a concave object-side surface and a concave image-side surface. The third lens 430 may have positive refractive power. The third lens 430 may have a convex object-side surface and a convex image-side surface. The fourth lens 440 may have positive refractive power. The fourth lens 440 may have a convex object-side surface and a convex image-side surface. The fifth lens 450 may have negative refractive power. The fifth lens 450 may have a convex object-side surface and a concave image-side surface.

[0136] Next, this disclosure describes one or more examples of a prism P that can serve as an optical path folding member. For reference, the prism described below is an example of one type of optical path folding member described herein and can be modified into another type of optical path folding member.

[0137] The prism P may include multiple surfaces. For example, the prism P may include a first surface PS1, a second surface PS2, a third surface PS3, and a fourth surface PS4. The first surface PS1 to the fourth surface PS4 may be sequentially connected to each other to form a small facet.

[0138] A prism P may include an incident surface, six reflecting surfaces, and an exiting surface. For example, the first surface PS1 of the prism P may be the incident surface and may also be the second and fourth reflecting surfaces; the second surface PS2 of the prism P may be the first reflecting surface; the third surface PS3 of the prism P may be the third reflecting surface and may also be the fifth reflecting surface and the exiting surface; and the fourth surface PS4 of the prism P may be the sixth reflecting surface.

[0139] The first surface PS1 of prism P can receive light emitted from the lens group LG. For example, a portion of the first surface PS1 of prism P can face the rearmost lens in the lens group LG. The first surface PS1 of prism P can reflect light. For example, a portion of the first surface PS1 of prism P can reflect light reflected from the second surface PS2. Additionally, another portion of the first surface PS1 of prism P can reflect light reflected from the third surface PS3.

[0140] The second surface PS2 of the prism P can reflect light incident through the first surface PS1. For example, the second surface PS2 of the prism P can reflect light incident through a portion of the first surface PS1 to another portion of the first surface PS1.

[0141] The third surface PS3 of the prism P can reflect and emit light. For example, a portion of the third surface PS3 of the prism P can reflect light reflected from the first surface PS1 to the fourth surface PS4, while another portion of the third surface PS3 of the prism P can emit light reflected from the fourth surface PS4 to the imaging plane IP.

[0142] The fourth surface PS4 of prism P can reflect light reflected from the third surface PS3. For example, the fourth surface PS4 of prism P can reflect light reflected from a portion of the third surface PS3 to another portion of the third surface PS3.

[0143] Prism P can achieve both total internal reflection and regular internal reflection. For example, the second surface PS2 and the fourth surface PS4 of prism P can achieve total internal reflection, while the first surface PS1 and the third surface PS3 of prism P can achieve regular internal reflection or specular reflection. For example, the angle of incidence of the first surface PS1 and the third surface PS3 can be greater than the angle of incidence of the second surface PS2 and the fourth surface PS4. As another example, the angle of incidence of the first surface PS1 and the third surface PS3 can be greater than the critical angle of the corresponding surface, while the angle of incidence of the second surface PS2 and the fourth surface PS4 can be less than the critical angle of the corresponding surface.

[0144] The first surface PS1, the second surface PS2, the third surface PS3, and the fourth surface PS4 of the prism P can form predetermined angles. For example, the first surface PS1 and the second surface PS2 can have an acute angle. As a specific example, the angle between the first surface PS1 and the second surface PS2 can be 26 degrees to 34 degrees. As another example, the first surface PS1 and the fourth surface PS4 can have an obtuse angle. As a specific example, the angle between the first surface PS1 and the fourth surface PS4 can be 146 degrees to 154 degrees. As yet another example, the second surface PS2 and the third surface PS3 can have an obtuse angle. As a specific example, the angle between the second surface PS2 and the third surface PS3 can be 146 degrees to 154 degrees. As yet another example, the third surface PS3 and the fourth surface PS4 can have an acute angle. As a specific example, the angle between the third surface PS3 and the fourth surface PS4 can be 26 degrees to 34 degrees.

[0145] The filter IF and the imaging plane IP can be positioned adjacent to the exit surface of the prism P.

[0146] A filter IF can block light of a specific wavelength. For example, the filter IF according to this exemplary embodiment can block infrared light. However, the types of light blocked by the filter IF are not limited to infrared light. For example, the filter IF can block ultraviolet light or visible light.

[0147] The imaging plane IP can be located at the point where the light reflected from the fourth reflective surface PS4 of the prism P converges or forms an image, and can be formed by an image sensor IS, etc. For example, the imaging plane IP can be formed on or within the image sensor IS.

[0148] The imaging lens system 400 configured as described above can be illustrated with the aberration characteristics shown in Figure 8. Tables 7 and 8 respectively show the lens characteristics and aspherical values ​​of the imaging lens system according to this exemplary embodiment.

[0149] Table 7 Surface number Components radius of curvature Thickness / Distance Refractive index Abbe number S1 First lens 5.96036 1.529 1.537 55.7 S2 237.688 0.351 S3 Second lens -54.829 0.399 1.621 26.0 S4 10.602 0.257 S5 Third lens 11.976 0.450 1.679 19.2 S6 -472.747 0.113 S7 Fourth lens 15.360 0.862 1.537 55.7 S8 -36.1138 0.135 S9 Fifth lens 49.7849 0.450 1.621 26.0 S10 5.30902 0.750 S11 Prism infinity 2.500 1.519 64.2 S12 infinity 3.000 1.519 64.2 S13 infinity 3.750 1.519 64.2 S14 infinity 3.750 1.519 64.2 S15 infinity 0.318 1.519 64.2 S16 infinity 3.200 1.519 64.2 S17 infinity 2.600 1.519 64.2 S18 infinity 0.450 S19 Filter infinity 0.210 1.519 64.2 S20 infinity 2.898 S21 Imaging plane infinity 0.003

[0150] Table 8 Surface number S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 K 0 0 0 0 0 0 -1.418E+01 0 0 5.614E-01 A 0 0 0 0 0 0 1.897E-02 0 0 -5.641E-03 B 0 0 0 0 0 0 3.404E-03 0 0 -1.169E-02 C 0 0 0 0 0 0 -2.238E-03 0 0 7.465E-03 D 0 0 0 0 0 0 0 0 0 2.819E-03 E 0 0 0 0 0 0 0 0 0 0 F 0 0 0 0 0 0 0 0 0 0 G 0 0 0 0 0 0 0 0 0 0 H 0 0 0 0 0 0 0 0 0 0 J 0 0 0 0 0 0 0 0 0 0

[0151] This disclosure will now describe an imaging lens system according to a fifth exemplary embodiment with reference to FIG9.

[0152] The imaging lens system 500 according to this exemplary embodiment may include a lens group LG and a prism P as a type of optical path folding member. However, the components of the imaging lens system 500 are not limited to those mentioned above. For example, the imaging lens system 500 may further include a filter IF and an imaging plane IP. The lens group LG and the prism P may be arranged sequentially from the object side. For example, the lens group LG may be disposed on the object side of the prism P, and the prism P may be disposed between the lens group LG and the imaging plane IP.

[0153] Next, we will describe examples of the components mentioned above.

[0154] The lens group LG may include multiple lenses. For example, the lens group LG may include a first lens 510, a second lens 520, a third lens 530, and a fourth lens 540 arranged sequentially from the object side. The first lens 510 to the fourth lens 540 may be arranged at predetermined intervals. For example, the image-side surface of the first lens 510 may not be in contact with the object-side surface of the second lens 520, and the image-side surface of the second lens 520 may not be in contact with the object-side surface of the third lens 530. However, the first lens 510 to the fourth lens 540 need not be arranged so that they do not contact each other. For example, the image-side surface of the first lens 510 may be in contact with the object-side surface of the second lens 520, and the image-side surface of the second lens 520 may be in contact with the object-side surface of the third lens 530.

[0155] Next, the characteristics of the first lens 510 to the fourth lens 540 will be described with reference to one or more exemplary embodiments of this disclosure.

[0156] The first lens 510 may have positive refractive power and a convex object-side surface and a concave image-side surface. The second lens 520 may have positive refractive power and a convex object-side surface and a concave image-side surface. The third lens 530 may have positive refractive power and a convex object-side surface and a concave image-side surface. The fourth lens 540 may have negative refractive power and a convex object-side surface and a concave image-side surface.

[0157] Next, this disclosure describes one or more examples of a prism P that can serve as an optical path folding member. For reference, the prism described below is an example of one type of optical path folding member described herein and can be modified into another type of optical path folding member.

[0158] The prism P may include multiple reflective surfaces. For example, the prism P may include a first reflective surface and a second reflective surface. The first and second reflective surfaces may be substantially parallel to each other. There may be a considerable distance between the first and second reflective surfaces. For example, the distance from the first reflective surface to the second reflective surface may be greater than the height ImgHT of the imaging plane. As another example, the distance from the first reflective surface to the second reflective surface may be greater than four times the height ImgHT of the imaging plane.

[0159] The filter IF and the imaging plane IP can be positioned adjacent to the exit surface of the prism P.

[0160] A filter IF can block light of a specific wavelength. For example, the filter IF according to this exemplary embodiment can block infrared light. However, the types of light blocked by the filter IF are not limited to infrared light. For example, the filter IF can block ultraviolet light or visible light.

[0161] The imaging plane IP can be located at the point where the light reflected from the prism P converges or forms an image, and can be formed by an image sensor IS, etc. For example, the imaging plane IP can be formed on or within the image sensor IS.

[0162] The imaging lens system 500 configured as described above can be illustrated with the aberration characteristics shown in Figure 10. Tables 9 and 10 respectively show the lens characteristics and aspherical values ​​of the imaging lens system according to this exemplary embodiment.

[0163] Table 9 Surface number Components radius of curvature Thickness / Distance Refractive index Abbe number S1 First lens 5.818 1.795 1.537 55.7 S2 25.349 0.100 S3 Second lens 20.693 1.159 1.667 20.3 S4 26.185 0.100 S5 Third lens 9.53363 0.811 1.537 55.7 S6 15.1724 0.103 S7 Fourth lens 28.8904 0.405 1.619 26.0 S8 5.47386 1.500 S9 Prism infinity 3.750 1.518 64.2 S10 infinity 17.250 1.518 64.2 S11 infinity 4.500 1.518 64.2 S12 infinity 0.300 S13 Filter infinity 0.210 1.518 64.2 S14 infinity 0.295 S15 Imaging plane infinity 0.005

[0164] Table 10 Surface number S1 S2 S3 S4 K 0.344928349 0 0 -99 A 9.70164E-05 -1.76601E-05 2.55457E-05 -0.001531536 B 2.73181E-05 -2.14958E-06 6.19014E-06 0.002042309 C -4.91204E-06 -2.90562E-07 8.79374E-07 -0.000863204 D 9.3407E-07 -8.86232E-09 6.91697E-08 0.000207981 E -8.39693E-08 1.21392E-09 3.18914E-09 -2.99433E-05 F 2.35343E-09 1.51258E-10 1.24428E-10 2.68181E-06 G -5.10444E-11 -5.95195E-13 2.71575E-11 -1.43975E-07 H 2.31185E-11 -1.48893E-12 6.20088E-12 3.15609E-09 J -1.5758E-12 -1.59842E-13 8.88953E-13 7.55353E-11 Surface number S5 S6 S7 S8 K -1.17E+01 0 0 5.900E-01 A -2.948E-03 6.24731E-05 -0.000103984 -1.125E-03 B 2.041E-03 1.08429E-05 -1.15055E-05 -1.025E-03 C -6.022E-04 1.98602E-06 -1.68379E-06 1.389E-03 D -1.099E-05 2.64153E-07 -2.29467E-07 -9.991E-04 E 4.42323E-05 1.79879E-08 -2.61396E-08 0.00039859 F -1.05033E-05 -3.00074E-09 -1.60817E-09 -9.29334E-05 G 1.13117E-06 -1.53564E-09 1.86611E-10 1.25407E-05 H -5.9262E-08 -4.38528E-10 -8.04452E-11 -9.0042E-07 J 1.22222E-09 -1.07522E-10 -1.71932E-11 2.64504E-08

[0165] Tables 11 to 13 show the optical characteristic values ​​and conditional expression values ​​of the imaging lens systems according to the first to fifth exemplary embodiments described above.

[0166] Table 11 project First exemplary embodiment Second exemplary embodiment Third exemplary embodiment Fourth exemplary embodiment Fifth exemplary embodiment f 15,000 13.992 16.420 23.000 27.188 f1 7.576 7.417 7.502 11.357 13.637 f2 -9.689 -9.948 -9.229 -14.283 136.425 f3 11.615 12.564 11.233 17.196 45.523 f4 14.761 12.649 17.517 20.182 -10.978 f5 -7.102 -6.483 -7.370 -9.613 - TTL 18.736 16.878 20.827 27.975 32.283 BFL 16.034 13.634 18.163 23.429 26.310

[0167] Table 12 conditional expression First exemplary embodiment Second exemplary embodiment Third exemplary embodiment Fourth exemplary embodiment Fifth exemplary embodiment BFL / TTL 0.856 0.808 0.872 0.837 0.815 V1-V2 29.76 29.76 29.76 29.76 35.365 f 15.00 13.99 16.42 23.00 27.188 TTL / f 1.249 1.206 1.268 1.216 1.187

[0168] Table 13 conditional expression First exemplary embodiment Second exemplary embodiment Third exemplary embodiment Fourth exemplary embodiment Fifth exemplary embodiment f / f1 1.9799 1.8864 2.1888 2.0253 1.9937 TTL / f 1.2491 1.2062 1.2684 1.2163 1.1874 f / PL 1.1111 1.2837 1.6257 1.7692 1.0662 (|fF|+|fR|) / PL 1.0872 1.2753 1.4724 1.6130 0.9653 fF / PL 0.5612 0.6805 0.7427 0.8736 0.5348 fR / PL -0.5260 -0.5948 -0.7297 -0.7395 -0.4305 LFS1 / PL 0.2946 0.3617 0.3956 0.4585 0.2282 LRS2 / PL 0.2795 0.3222 0.3644 0.4084 0.2147 (LFS1+LRS2) / PL 0.5741 0.6839 0.7599 0.8669 0.4428 f1 / PL 0.5612 0.6805 0.7427 0.8736 0.5348 f5 / PL -0.5260 -0.5948 -0.7297 -0.7395 0.0000 (f1+f2) / PL -0.1565 -0.2322 -0.1710 -0.2251 5.8848 (f1+f2+f3) / PL 0.7039 0.9204 0.9412 1.0977 7.6700 (f1+f2+f3+f4) / PL 1.7973 2.2746 2.4027 2.2331 8.2489 (f1+f2+f3+f4+f5) / PL 1.2712 1.6799 1.6730 1.4937 8.2489 R1 / PL 0.2946 0.3617 0.3956 0.4585 0.2282 R10 / PL| 0.2795 0.3222 0.3644 0.4084 - (R1+R10) / PL 0.5741 0.6839 0.7599 0.8669 - TLG / PL 0.2002 0.2976 0.2637 0.3497 0.1754 ImgHT / PL 0.1481 0.1835 0.0990 0.0923 0.1647 (TTL+ImgHT) / PL 1.5360 1.7319 2.1610 2.2442 1.4307 (TTL+f) / PL 2.4990 2.8321 3.6877 3.9211 2.3322

[0169] Next, an electronic device according to one or more exemplary embodiments of the present disclosure will be described with reference to FIG11.

[0170] An electronic device according to one or more exemplary embodiments of this disclosure may include an imaging lens system according to one or more exemplary embodiments of this disclosure. For example, the electronic device may include one or more of the imaging lens systems according to the first to fifth exemplary embodiments. As a specific example, the electronic device may include the imaging lens system 100 according to the first exemplary embodiment.

[0171] The electronic device according to an exemplary embodiment may be a portable terminal 1000 as shown in FIG11. However, the type of electronic device is not limited to the portable terminal 1000. For example, the electronic device according to another exemplary embodiment may be a laptop computer.

[0172] The portable terminal 1000 may include one or more camera modules 10 and 20. For example, two camera modules 10 and 20 may be installed at predetermined intervals in the body 1002 of the portable terminal 1000. The first camera module 10 and the second camera module 20 can capture images of objects in the same direction. For example, the first camera module 10 and the second camera module 20 may be mounted parallel to each other on a surface of the electronic device 1000.

[0173] At least one of the first camera module 10 and the second camera module 20 may include an imaging lens system according to one of the first exemplary embodiments to the fifth exemplary embodiments. For example, the first camera module 10 may include an imaging lens system 100 according to the first exemplary embodiment.

[0174] The first camera module 10 can capture images of objects positioned at a long distance. In other words, the focal length of the first camera module 10 can be greater than the focal length of the second camera module 20.

[0175] In summary, one or more embodiments disclosed herein can provide an imaging lens system that can be installed in a small or thin terminal.

[0176] In addition, one or more embodiments disclosed herein may provide a camera module with a telephoto imaging lens system.

[0177] Although specific examples have been shown and illustrated above, it will become 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 examples illustrated herein should be considered illustrative only and not for limiting purposes. Descriptions of features or manner in each example should be considered applicable to similar features or manner in other examples. Suitable results may be achieved if the described technology is implemented in a different order, and / or if components in the described system, architecture, apparatus, 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 defined by the detailed description but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents should be construed as included in this disclosure.

[0178] 10: First camera module / Camera module 20: Second camera module / Camera module 100, 200, 300, 400, 500: Imaging lens system 110, 210, 310, 410, 510: First lens 120, 220, 320, 420, 520: Second lens 130, 230, 330, 430, 530: Third lens 140, 240, 340, 440, 540: Fourth lens 150, 250, 350, 450: Fifth lens 1000: Portable terminal / electronic device 1002:Ontology IF: Filter IP: Imaging Plane IS: Image Sensor LG: Lens Group P: Prism PS1: First Surface PS2: Second Surface PS3: The Third Surface PS4: Fourth Surface / Fourth Reflective Surface

Claims

1. An imaging lens system, comprising: The first lens includes positive refractive power; the second lens includes positive refractive power; the third lens includes a convex object side surface. A fourth lens, including a refractive force; and an optical path folding member, disposed on the image side of the fourth lens and including four or more reflective surfaces, wherein the first lens to the fourth lens are arranged sequentially from the object side toward the imaging plane, wherein the imaging lens system has a total of four lenses containing refractive forces, wherein the imaging lens system satisfies 0.7 < BFL / TTL < 0.9, where BFL is the distance from the image side surface of the last lens closest to the imaging plane to the imaging plane, and TTL is the distance from the object side surface of the first lens to the imaging plane, and wherein the imaging lens system satisfies -1.2 < fR / PL < -0.40 or 1.52 < (TTL+ImgHT) / PL < 2.32, where fR is the focal length of the last lens, ImgHT is the height of the imaging plane, and PL is the distance from the incident surface of the optical path folding member to the exit surface of the optical path folding member.

2. The imaging lens system as claimed in claim 1, wherein the first lens has a convex object-side surface.

3. The imaging lens system as claimed in claim 1, wherein the second lens has a convex object-side surface.

4. The imaging lens system of claim 1, wherein the second lens has a concave image-side surface.

5. The imaging lens system as claimed in claim 1, wherein the third lens has a concave image-side surface.

6. The imaging lens system of claim 1, wherein the fourth lens has a concave image-side surface.

7. The imaging lens system as claimed in claim 1, wherein 10 mm < f, where f is the focal length of the imaging lens system.

8. The imaging lens system as claimed in claim 1, wherein 1.05 < TTL / f, where f is the focal length of the imaging lens system.

9. The imaging lens system as claimed in claim 1, wherein 0.80 < f / PL < 2.0, where f is the focal length of the imaging lens system.

10. The imaging lens system of claim 1, wherein 0.10 < TLG / PL < 0.4, where TLG is the distance from the object-side surface of the first lens to the image-side surface of the last lens.

11. An electronic device comprising: One or more camera modules, wherein at least one of the one or more camera modules includes the imaging lens system as described in claim 1.

Images