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CN-117706743-B - Optical imaging system

CN117706743BCN 117706743 BCN117706743 BCN 117706743BCN-117706743-B

Abstract

An optical imaging system includes an imaging lens group composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in this order from an object side to an image side along an optical axis, wherein the first lens has positive optical power, the second lens has negative optical power, the signs of the optical powers of the third lens and the fourth lens are different from each other, the optical power of the fifth lens is positive, the optical power of the sixth lens is negative, at least one of an object side surface and an image side surface of the sixth lens has an inflection point, and Abbe numbers of the second lens and the fourth lens are smaller than 25, a plurality of spacer elements including the third spacer element and the fourth spacer element, and a lens barrel, a radius of curvature R9 of an object side surface of the fifth lens, a spacing EP34 of an image side surface of the third spacer element and an object side surface of the fourth spacer element in an optical axis direction and a maximum thickness CP4 of the fourth spacer element in the optical axis direction satisfy 11/(R9+Ep 4) 4.

Inventors

  • WU TONG
  • XU WUCHAO
  • CHENG LIBANG
  • DAI FUJIAN
  • ZHAO LIEFENG

Assignees

  • 浙江舜宇光学有限公司

Dates

Publication Date
20260505
Application Date
20220915

Claims (15)

  1. 1. An optical imaging system, comprising: The imaging lens group comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged from an object side to an image side along an optical axis, wherein the first lens is provided with positive focal power, the object side is a convex surface, the image side is a concave surface, the second lens is provided with negative focal power, the object side is a convex surface, the image side is a concave surface, the signs of the focal power of the third lens and the focal power of the fourth lens are different, the object side of the third lens is a convex surface, the image side of the fourth lens is a concave surface, the focal power of the fifth lens is positive, the object side and the image side are both convex surfaces, the focal power of the sixth lens is negative, at least one of the object side and the image side of the sixth lens is provided with an inflection point, the object side and the image side of the sixth lens are both concave surfaces, and the Abbe numbers of the second lens and the fourth lens are less than 25; A plurality of spacing elements including a third spacing element disposed between and in contact with an image side of the third lens and a fourth spacing element disposed between and in contact with an image side of the fourth lens, and A lens barrel for accommodating the imaging lens group and the plurality of spacer elements; the number of lenses having optical power in the optical imaging system is six; The radius of curvature R9 of the object side surface of the fifth lens, the spacing EP34 of the image side surface of the third spacing element and the object side surface of the fourth spacing element along the optical axis direction and the maximum thickness CP4 of the fourth spacing element along the optical axis direction meet 11.60-R9/(EP 34+CP4) 32.73.
  2. 2. The optical imaging system of claim 1, wherein the plurality of spacer elements further comprises a first spacer element disposed between and in contact with an image side of the first lens, a second spacer element disposed between and in contact with an image side of the second lens, and a fifth spacer element disposed between and in contact with an image side of the fifth lens, wherein Dim is an outer diameter of an image side of a spacer element of an image side of a lens in the imaging lens group having an abbe number greater than 50, TD is a distance on the optical axis from an object side of the first lens to an image side of the sixth lens; wherein, when i is taken as 1, D1m represents the outer diameter of the image side surface of the first interval element, and D1m and TD meet that D1m/TD is less than or equal to 0.71 and less than or equal to 0.93; When 3 is taken, D3m represents the outer diameter of the image side surface of the third spacing element, D3m and TD satisfy 0.81≤D3m/TD≤1.21, and When i is taken as 5, D5m represents the outer diameter of the image side surface of the fifth interval element, and D5m and TD satisfy that D5m/TD is less than or equal to 1.51 and less than or equal to 1.76.
  3. 3. The optical imaging system of claim 1, wherein the plurality of spacer elements further comprises a first spacer element disposed between and in contact with an image side of the first lens, a second spacer element disposed between and in contact with an image side of the second lens, and a fifth spacer element disposed between and in contact with an image side of the fifth lens, wherein f is an effective focal length of the optical imaging system and djm is an inner diameter of an image side of a spacer element of the imaging lens group having a negative optical power; Wherein, the When j is taken as 2, d2m represents the inner diameter of the image side surface of the second interval element, and f and d2m are satisfied that f/d2m is less than or equal to 2.14 and less than or equal to 2.34; When j is taken to be 3, d3m represents the inner diameter of the image side surface of the third interval element, and f and d3m are 1.83-1.98; when j is taken to be 4, d4m represents the inner diameter of the image side surface of the fourth interval element, and f and d4m satisfy that 1.20 is less than or equal to f/d4m is less than or equal to 1.33.
  4. 4. The optical imaging system of claim 1, wherein the plurality of spacer elements further comprises a first spacer element disposed between the first lens and the second lens and in contact with an image side surface of the first lens, wherein, The combined focal length f12 of the first lens and the second lens, the front end face of the lens barrel close to the object side and the interval EP01 of the object side face of the first interval element along the optical axis direction and the maximum thickness CP1 of the first interval element along the optical axis direction meet that f 12/(EP 01+CP1) is less than or equal to 5.14 and less than or equal to 6.70.
  5. 5. The optical imaging system of claim 1, wherein the plurality of spacer elements further comprises a first spacer element disposed between and in contact with an image side of the first lens and a second spacer element disposed between and in contact with an image side of the second lens, The radius of curvature R3 of the object side of the second lens, the radius of curvature R4 of the image side of the second lens, the inner diameter d1m of the image side of the first spacing element and the inner diameter d2s of the object side of the second spacing element satisfy that 9.47 is less than or equal to (R3X R4)/(d 1m X d2 s) is less than or equal to 33.52.
  6. 6. The optical imaging system of claim 1, wherein at least two of the first to third lenses are meniscus lenses in a paraxial region.
  7. 7. The optical imaging system of claim 1, wherein the radius of curvature R2 of the image side of the first lens and the radius of curvature R12 of the image side of the sixth lens satisfy R2> R12>0.
  8. 8. The optical imaging system of any of claims 1 to 7, wherein the plurality of spacer elements further comprises a second spacer element disposed between and in contact with an image side of the second lens, wherein, The combined focal length f23 of the second lens and the third lens and the inner diameter d2m of the image side surface of the second spacing element satisfy that 4.51 is more than or equal to |f23|/d2m is more than or equal to 11.05.
  9. 9. The optical imaging system according to any one of claims 1 to 7, wherein a combined focal length f34 of the third lens and the fourth lens, an outer diameter D3s of an object side surface of the third spacing element, and an outer diameter D3m of an image side surface of the third spacing element satisfy 3.32 +.f34 +./(d3s+d3m) +.23.04.
  10. 10. The optical imaging system of any of claims 1 to 7, wherein an effective focal length f4 of the fourth lens, an inner diameter D4s of an object side of the fourth spacing element, and an outer diameter D4s of the object side of the fourth spacing element satisfy 1.50 +.f4 +./(d4s+d4s) +.17.32.
  11. 11. The optical imaging system of any of claims 2 to 7, wherein the plurality of spacer elements further comprises a fifth spacer element disposed between and in contact with an image side of the fifth lens, wherein, The effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, the maximum thickness CP3 of the third spacing element along the optical axis direction and the maximum thickness CP5 of the fifth spacing element along the optical axis direction meet that (f5+f6)/(CP 3+CP5) is less than or equal to 0.98 and less than or equal to 10.72.
  12. 12. The optical imaging system of any of claims 1 to 7, wherein the plurality of spacer elements further comprises a fifth spacer element disposed between and in contact with an image side of the fifth lens, wherein, The radius of curvature R10 of the image side surface of the fifth lens, the radius of curvature R11 of the object side surface of the sixth lens, the spacing EP45 between the image side surface of the fourth spacing element and the object side surface of the fifth spacing element along the optical axis direction satisfies that-12.44 is less than or equal to (R10+R11)/EP 45 is less than or equal to-5.98.
  13. 13. The optical imaging system of any of claims 1 to 7, wherein the plurality of spacer elements further comprises a fifth spacer element disposed between and in contact with an image side of the fifth lens, wherein, The inner diameter d5s of the object side surface of the fifth spacing element, the inner diameter d5m of the image side surface of the fifth spacing element and the air space T56 between the fifth lens and the sixth lens on the optical axis satisfy that (d5s+d5m)/T56 is not less than 23.37 and not more than 31.09.
  14. 14. The optical imaging system according to any one of claims 1 to 7, wherein an inner diameter D0s of a front end face of the lens barrel near the object side, an outer diameter D0s of a front end face of the lens barrel near the object side, and an entrance pupil diameter EPD of the optical imaging system satisfy 3.19 +≤d0s+d0s)/EPD +.3.90.
  15. 15. The optical imaging system of any of claims 1 to 7, wherein the plurality of spacer elements further comprises a first spacer element disposed between and in contact with an image side of the first lens and a second spacer element disposed between and in contact with an image side of the second lens, The effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the intervals EP12 of the image side surface of the first spacing element and the object side surface of the second spacing element along the optical axis direction, and the intervals EP23 of the image side surface of the second spacing element and the object side surface of the third spacing element along the optical axis direction satisfy that 6.87 is less than or equal to |f1+f2|/(EP 12+EP 23) is less than or equal to 17.51.

Description

Optical imaging system Statement of divisional application The application is a divisional application of China patent application with the application number 202211123589.5, which is filed in 2022, 09 and 15 days and has the name of an optical imaging system. Technical Field The application relates to the field of optical elements, in particular to an optical imaging system. Background In recent years, with the popularization of mobile phones in daily life, people have not only increased requirements on imaging quality of mobile phone lenses, but also focused on the appearance of the lenses, so that ultra-thin large-image-plane mobile phone lenses gradually become a development trend of industry. However, the ultra-thin large-image-surface lens often has the limit of the external dimension of the lens barrel, and particularly for a plurality of imaging lenses, the design difficulty is high. For example, for a 6P imaging lens with a large aperture and a large image plane and with ultra-thin characteristics, the whole lens barrel is thinner, the gear span of the two rear lenses is larger, the offset is larger, the performance of the imaging system is easily affected, and the light converging capability needs to be further enhanced. Meanwhile, when the offset of the imaging lens is large, the problem of unstable assembly is easy to occur, so that the overall quality of the lens is affected. Therefore, how to improve the assembly stability and the flare problem of the lens with larger aberration under the condition of meeting the requirements of customers on the appearance and the overall size of the lens, so that the lens has good imaging quality and is one of the key research subjects of designers. Disclosure of Invention The application provides an optical imaging system comprising an imaging lens group composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged from an object side to an image side along an optical axis, wherein the first lens has positive optical power, the signs of the optical power of the third lens and the optical power of the fourth lens are different, the optical power of the fifth lens is positive, the optical power of the sixth lens is negative, at least one of the object side and the image side of the sixth lens has an inflection point, and Abbe numbers of the second lens and the fourth lens are smaller than 25, a plurality of spacing elements including a third spacing element which is arranged between the third lens and the fourth lens and is in contact with the image side of the third lens and a fifth spacing element which is arranged between the fifth lens and the sixth lens and is in contact with the image side of the fifth lens, and a lens barrel for accommodating the imaging lens group and the plurality of spacing elements, an effective focal length f5 of the fifth lens, an effective focal length f6 of the sixth lens and a spacing element of the fifth lens which is in a maximum thickness of 3+5+5 in a direction of a maximum thickness of 3+5 (a maximum thickness of 3+5+5) of the optical axis and a maximum thickness of the third lens is satisfied in a direction of 3+5. In one embodiment, the plurality of spacer elements further comprises a first spacer element disposed between the first lens and the second lens and in contact with the image side of the first lens, a second spacer element disposed between the second lens and the third lens and in contact with the image side of the second lens, and a fourth spacer element disposed between the fourth lens and the fifth lens and in contact with the image side of the fourth lens, wherein the optical imaging system satisfies 0.5< Dim/TD <2.0, wherein Dim is the outer diameter of the image side of the spacer element of the lens having an Abbe number greater than 50 in the imaging lens group, TD is the distance on the optical axis from the object side of the first lens to the image side of the sixth lens, wherein D1m represents the outer diameter of the image side of the first spacer element when i is taken 1, D2m represents the outer diameter of the image side of the second spacer element when i is taken 2, D3m represents the outer diameter of the image side of the third spacer element when i is taken 3, D4m represents the outer diameter of the image side of the fourth spacer element when i is taken 4, and D5 when i is taken 5. In one embodiment, the plurality of spacer elements further comprises a first spacer element disposed between the first lens and the second lens and in contact with the image side of the first lens, a second spacer element disposed between the second lens and the third lens and in contact with the image side of the second lens, and a fourth spacer element disposed between the fourth lens and the fifth lens and in contact with the image side of the fourth lens, wherein the optical imaging system satisfies 1<f/djm <3, wherein f is an effectiv