# US 2016/0259147 A1 · Imaging system, image capturing apparatus and electronic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0259147 A1 - Document ID: US20160259147A1 - Status: Published application - Kind: A1 - Application number: 14/727,302 - Filed: 2015-06-01 - Published: 2016-09-08 - Earliest claimed: 2015-03-02 - Assignees: Largan Precision Co., Ltd. - Applicants: Largan Precision Co., Ltd. - Inventors: Chun-Che Hsueh; Wei-Yu Chen - Web page: https://patentgrep.com/patent/US20160259147A1 ## CPC - G02B 13/0045: {having five or more lenses} - G02B 9/60: having five components only - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An imaging system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The second lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof. The third lens element has refractive power. The fourth lens element with refractive power has an image-side surface being concave in a paraxial region thereof. The fifth lens element with refractive power has an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof. ## Claims ### Claim 1 An imaging system comprising, in order from an object side to an image side: a first lens element with positive refractive power having an object-side surface being convex in a paraxial region thereof; a second lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof; a third lens element having refractive power; a fourth lens element with refractive power having an image-side surface being concave in a paraxial region thereof, wherein an object-side surface and the image-side surface of the fourth lens element are aspheric, and the image-side surface of the fourth lens element comprises at least one convex shape in an off-axial region thereof; and a fifth lens element with refractive power having an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof, wherein the object-side surface and the image-side surface of the fifth lens element are aspheric, and the image-side surface of the fifth lens element comprises at least one convex shape in an off-axial region thereof; wherein the imaging system has a total of five lens elements with refractive power, there is an air gap between any two of the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element that are adjacent to each other, a central thickness of the fourth lens element is CT4, an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the fourth lens element and the fifth lens element is T45, a focal length of the imaging system is f, a curvature radius of an object-side surface of the third lens element is R5, a curvature radius of an image-side surface of the third lens element is R6, an Abbe number of the second lens element is V2, an Abbe number of the third lens element is V3, an Abbe number of the fourth lens element is V4, and the following conditions are satisfied: CT4/T34<1.20; CT4/T45<1.60; |f/R5|+|f/R6|<1.10; and 1.75<(V2+V4)/V3. ### Claim 2 (depends on 1) The imaging system of claim 1, wherein the object-side surface of the fourth lens element is convex in a paraxial region thereof. ### Claim 3 (depends on 2) The imaging system of claim 2, wherein the Abbe number of the third lens element is V3, and the following condition is satisfied: V3<30. ### Claim 4 (depends on 2) The imaging system of claim 2, wherein the central thickness of the fourth lens element is CT4, the axial distance between the third lens element and the fourth lens element is T34, and the following condition is satisfied: CT4/T34<1.0. ### Claim 5 (depends on 1) The imaging system of claim 1, wherein the central thickness of the fourth lens element is CT4, the axial distance between the fourth lens element and the fifth lens element is T45, and the following condition is satisfied: CT4/T45<1.48. ### Claim 6 (depends on 1) The imaging system of claim 1, wherein the central thickness of the fourth lens element is CT4, the axial distance between the fourth lens element and the fifth lens element is T45, and the following condition is satisfied: CT4/T45<1.25. ### Claim 7 (depends on 1) The imaging system of claim 1, wherein the third lens element has positive refractive power. ### Claim 8 (depends on 1) The imaging system of claim 1, wherein the first lens element has an image-side surface being concave in a paraxial region thereof. ### Claim 9 (depends on 1) The imaging system of claim 1, wherein a curvature radius of the object-side surface of the fourth lens element is R7, the focal length of the imaging system is f, and the following condition is satisfied: |R7|f|<3.0. ### Claim 10 (depends on 9) The imaging system of claim 9, wherein an f-number of the imaging system is Fno, an axial distance between the object-side surface of the first lens element and an image surface is TL, a half of a maximal field of view of the imaging system is HFOV, and the following conditions are satisfied: 1.6|f1|; |f3|>|f2|; |f3|>|f4|; and |f3|>|f5|. ### Claim 14 (depends on 1) The imaging system of claim 1, wherein a curvature radius of the object-side surface of the fourth lens element is R7, a curvature radius of the image-side surface of the fourth lens element is R8, a curvature radius of the object-side surface of the fifth lens element is R9, a curvature radius of the image-side surface of the fifth lens element is R10, the focal length of the imaging system is f, and the following condition is satisfied: (|R7|+|R8|+|R9|+|R10|)/f<3.5. ### Claim 15 (depends on 1) The imaging system of claim 1, wherein the axial distance between the third lens element and the fourth lens element is T34, the axial distance between the fourth lens element and the fifth lens element is T45, a sum of axial distances between any two of the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element that are adjacent to each other is ΣAT, and the following condition is satisfied: 0.60<(T34+T45)/ΣAT<0.80. ### Claim 16 (depends on 1) The imaging system of claim 1, wherein the Abbe number of the second lens element is V2, the Abbe number of the third lens element is V3, the Abbe number of the fourth lens element is V4, and the following condition is satisfied: V2+V3+V4<90. ### Claim 17 (depends on 1) The imaging system of claim 1, wherein a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, the central thickness of the fourth lens element is CT4, a central thickness of the fifth lens element is CT5, and CT5 is larger than CT1, CT2, CT3, and CT4. ### Claim 18 (depends on 1) The imaging system of claim 1, wherein a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, the central thickness of the fourth lens element is CT4, a central thickness of the fifth lens element is CT5, and the following condition is satisfied: (CT2+CT3+CT4)/CT5<1.25. ### Claim 19 (depends on 1) The imaging system of claim 1, wherein a curvature radius of the image-side surface of the fourth lens element is R8, a curvature radius of the object-side surface of the fifth lens element is R9, and the following condition is satisfied: 1.20