Search

CN-117761877-B - Optical imaging system

CN117761877BCN 117761877 BCN117761877 BCN 117761877BCN-117761877-B

Abstract

The application discloses an optical imaging system, which comprises an imaging lens group, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are sequentially arranged from an object side to an image side along an optical axis, the first lens has positive focal power, the second lens has negative focal power, the signs of the focal powers of the third lens and the fourth lens are different, the fifth lens has positive focal power, the sixth lens has negative focal power, both the object side surface and the image side surface of the sixth lens have anti-curvature points, and the refractive indexes of the second lens and the fourth lens are larger than 1.6; the plurality of spacing elements includes a second spacing element, a third spacing element, and a fourth spacing element, and the radius of curvature R8 of the image side surface of the fourth lens, the spacing EP23 of the image side surface of the second spacing element and the object side surface of the third spacing element in the optical axis direction, and the spacing EP34 of the image side surface of the third spacing element and the object side surface of the fourth spacing element in the optical axis direction satisfy 11< R8/(EP 23+EP 34) <55.

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 (16)

  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 has positive focal power, the object side is a convex surface, the image side is a concave surface, the second lens has negative focal power, the object side is a convex surface, the image side is a concave surface, the signs of the focal powers of the third lens and 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 fifth lens has positive focal power, the object side and the image side are both convex surfaces, the sixth lens has negative focal power, the object side and the image side of the sixth lens are both anti-curvature points, the object side and the image side of the sixth lens are both concave surfaces, and the refractive indexes of the second lens and the fourth lens are both more than 1.6; A plurality of spacing elements including a second spacing element disposed between and in contact with an image side of the second lens, 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 R8 of the image side surface of the fourth lens, the spacing 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, and 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 satisfy that R8/(EP 23+EP 34) is not more than 11.85 and not more than 54.38.
  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 and a fifth spacer element disposed between and in contact with an image side of the fifth lens, Dis is the outer diameter of the object side of the spacer element of the image side of the lens in the imaging lens group with abbe number greater than 50, f is the effective focal length of the optical imaging system; Wherein, when i is taken as1, D1s represents the outer diameter of the object side surface of the first interval element, and D1s and f satisfy that D1s/f is more than or equal to 0.72 and less than or equal to 0.93; When i is taken as 3, D3s represents the outer diameter of the object side surface of the third spacing element, D3s and f satisfy 0.81≤D3s/f≤1.13, and When i is taken as 5, D5s represents the outer diameter of the object side surface of the fifth spacing element, and D5s and f satisfy that D5s/f is less than or equal to 1.39 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 and a fifth spacer element disposed between and in contact with an image side of the fifth lens, Djm is the outer diameter of the image side of the spacer element of the image side of the positive power lens in the imaging lens group, EPD is the entrance pupil diameter of the optical imaging system; Wherein when j is 1, D1m represents the outer diameter of the image side surface of the first interval element, and D1m and EPD meet that D1m/EPD is less than or equal to 1.28 and less than or equal to 1.65; When j is taken to be 3, D3m represents the outer diameter of the image side surface of the third interval element, and D3m and EPD meet that D3m/EPD is less than or equal to 1.49 and less than or equal to 1.77; when j is taken to be 4, D4m represents the outer diameter of the image side surface of the fourth spacing element, D4m satisfies 2.39≤D4m/EPD≤2.42 with EPD, and When j is taken to be 5, D5m represents the outer diameter of the image side surface of the fifth interval element, and D5m and EPD satisfy that D5m/EPD is less than or equal to 2.44 and less than or equal to 3.22.
  4. 4. The optical imaging system of claim 1, wherein the spacer element further comprises a first spacer element disposed between the first lens and the second lens and in contact with an image side of the first lens, wherein, An on-axis distance TD from an object side surface of the first lens to an image side surface of the sixth lens, an effective focal length f of the optical imaging system, a front end surface of the lens barrel near the object side, and an interval EP01 of the object side surface of the first spacing element in the optical axis direction satisfy 4.63 (td×f)/(EP 01×d0s) 6.70 with an inner diameter d0s of the front end surface of the lens barrel near the object side.
  5. 5. The optical imaging system of claim 1, wherein the spacer element further comprises a first spacer element disposed between the first lens and the second lens and in contact with an image side of the first lens, wherein, The effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the inner diameter d1s of the object side surface of the first spacing element and the inner diameter d1m of the image side surface of the first spacing element satisfy 6.07 < f1 xf 2 </(d 1s xd 1 m) 10.47.
  6. 6. The optical imaging system of claim 1, wherein at least two of the first lens to the fourth lens are meniscus lenses in a paraxial region.
  7. 7. The optical imaging system of claim 1, wherein the radius of curvature R1 of the object-side surface of the first lens and the radius of curvature R2 of the image-side surface of the first lens satisfy R2> R1>0.
  8. 8. The optical imaging system of any of claims 1 to 7, wherein the spacer element further comprises a first spacer element disposed between the first lens and the second lens and in contact with an image side of the first lens, wherein, The radius of curvature R3 of the object side surface of the second lens, the radius of curvature R4 of the image side surface of the second lens, the intervals EP12 of the image side surface of the first interval element and the object side surface of the second interval element along the optical axis direction and the maximum thickness CP2 of the second interval element along the optical axis direction satisfy that (R3+R4)/(EP 12+CP 2) is less than or equal to 30.85 and less than or equal to 76.76.
  9. 9. The optical imaging system according to any one of claims 1 to 7, wherein a radius of curvature R5 of the object side surface of the third lens, a radius of curvature R6 of the image side surface of the third lens, an inner diameter d2s of the object side surface of the second spacing element, and an inner diameter d3s of the object side surface of the third spacing element satisfy 0< |r6/r5|× (d 3s/d2 s) +.5.18.
  10. 10. The optical imaging system according to any one of claims 1 to 7, wherein an effective focal length f4 of the fourth lens, an inner diameter D3m of an image side surface of the third spacing element, and an outer diameter D3m of the image side surface of the third spacing element satisfy 2.37 +.f4|/(d3m+d3m) <25.
  11. 11. The optical imaging system of any of claims 1 to 7, wherein the spacer element 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 maximum thickness CP4 of the fourth spacing element along the optical axis direction, the spacing EP45 of the image side surface of the fourth spacing element and the object side surface of the fifth spacing element along the optical axis direction satisfy that f 5/(CP4+EP 45) is less than or equal to 3.11 and less than or equal to 7.26.
  12. 12. The optical imaging system of any of claims 2 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 fifth spacer element disposed between and in contact with an image side of the fifth lens, The effective focal length f1 of the first lens, the effective focal length f6 of the sixth lens, the distance EP01 between the front end surface of the lens barrel, which is close to the object side, and the object side surface of the first spacing element along the optical axis direction, and the maximum thickness CP5 of the fifth spacing element along the optical axis direction meet the conditions that (f1+f6)/(EP 01+CP5) is less than or equal to 1.09 and less than or equal to 2.21.
  13. 13. The optical imaging system of any of claims 1 to 7, wherein the spacer element 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 and the maximum thickness CP5 of the fifth spacing element along the optical axis direction satisfy that 1.68 is less than or equal to |f5+f6|/CP5 is less than or equal to 15.93.
  14. 14. The optical imaging system according to any one of claims 1 to 7, wherein a radius of curvature R8 of the image side surface of the fourth lens, a radius of curvature R9 of the object side surface of the fifth lens, an inner diameter d4s of the object side surface of the fourth spacing element, and an inner diameter d4m of the image side surface of the fourth spacing element satisfy 5.76 +.r8xr9)/(d4sxd4m) +.38.67.
  15. 15. The optical imaging system of any of claims 1 to 7, wherein the spacer element 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, the radius of curvature R10 of the image side surface of the fifth lens and the radius of curvature R11 of the object side surface of the sixth lens satisfy that (d5sxd5m)/(R10xR11) is 5.02≤8.53.
  16. 16. The optical imaging system according to any one of claims 1 to 7, wherein an inner diameter D0m of a rear end face of the lens barrel near the image side, an outer diameter D0m of the rear end face of the lens barrel near the image side, and a radius of curvature R12 of the image side of the sixth lens satisfy 4.18≤d0m+d0m)/r12≤9.52.

Description

Optical imaging system Statement of divisional application The application is a divisional application of China patent application with the application number 202211123850.1, 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, not only are imaging quality requirements of mobile phone lenses higher and higher, but also the appearance and the overall size of the lenses are paid more attention to. On the one hand, the lens is required to have specifications of large aperture, high pixel and the like so as to meet the clear imaging effect under the condition of insufficient light, and on the other hand, customers pursue the characteristics of attractive appearance and miniaturization of the lens. For the limit of the overall dimension of a general lens barrel of the lens, such as a 6P ultra-thin imaging lens with a large image plane, each gear span of the lens barrel is large, the step difference is large, the influence on the performance of an imaging system is easy to be caused, and in addition, the assembly stability caused by the large step difference is poor, so that the overall quality of the lens can be influenced. Therefore, how to make the lens have good imaging quality and structural guarantee the assembling stability under the condition of meeting the requirements of customers on the appearance and the overall size of the lens is one of the key research subjects of designers. Disclosure of Invention The present 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 arranged in 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 power of the third lens and the optical power of the fourth lens are different, the signs of the optical power of the fifth lens and the optical power of the sixth lens are different, the object side surface and the image side surface of the sixth lens each have an inflection point, and refractive indexes of the second lens and the fourth lens are greater than 1.6, a plurality of spacer elements including a first spacer element interposed between the first lens and the second lens and in contact with the image side surface of the first lens and a fifth spacer element interposed between the fifth lens and the sixth lens and in contact with the image side surface of the fifth lens, and a lens barrel for accommodating the imaging lens group and the plurality of spacer elements, an effective focal length f1 of the first lens, an effective focal length f6 of the sixth lens and a spacer element in a direction of 0+5.01 in which a front end face of the first lens and a front end face of the sixth lens near to the optical axis of the first lens and a 5+0.01 and a spacer element in a direction of the first end face of the first lens and a 5+0+5. In one embodiment, the plurality of spacer elements further comprises a second spacer element disposed between the second lens and the third lens and in contact with the image side of the second lens, a third spacer element disposed between the third lens and the fourth lens and in contact with the image side of the third 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< Dis/f <2.0, wherein Dis is the outer diameter of the object side of the spacer element of the lens having an Abbe number greater than 50 in the imaging lens group, f is the effective focal length of the optical imaging system, wherein D1s represents the outer diameter of the object side of the first spacer element when i is taken to be 1, D2s represents the outer diameter of the object side of the second spacer element when i is taken to be 3, D3s represents the outer diameter of the object side of the third spacer element when i is taken to be 4, and D5s represents the outer diameter of the object side of the fifth spacer element when i is taken to be 5. In one embodiment, the plurality of spacer elements further includes a second spacer element disposed between the second lens and the third lens and in contact with an image side of the second lens, a third spacer element disposed between the third lens and the fourth lens and in contact with an image side of the third lens, and a fourth spacer element disposed between the fourth lens and the fifth lens and in contact with an image side of the fourth lens, wherein the optical imaging system satisfies 1< Djm/EPD <4, wherein Djm is an outer diameter of an image side of the spacer element of the imaging le