Optical imaging lens group including seven lenses +−+−−+−, +−−−−+−, +−++−+−, +−+−++−or +++−++− refractive powers
The disclosure provides an optical imaging lens group. The optical imaging lens group sequentially includes from an object side to an image side along an optical axis of the optical imaging lens group: a first lens with a positive refractive power; a second lens with a refractive power, an image-side surface of the second lens is a concave surface; a third lens with a refractive power; a fourth lens with a refractive power, an image-side surface of the fourth lens is a concave surface; a fifth lens with a refractive power; a sixth lens with a refractive power, an image-side surface of the sixth lens is a concave surface; and a seventh lens with a negative refractive power. A maximum field of view FOV of the optical imaging lens group and an effective focal length f of the optical imaging lens group satisfy tan(FOV/2)*f>5 mm.
1. An optical imaging lens group, sequentially comprising from an object side to an image side along an optical axis of the optical imaging lens group:
a first lens with a positive refractive power;
a second lens with a refractive power, an image-side surface of the second lens thereof is a concave surface;
a third lens with a refractive power;
a fourth lens with a refractive power, an image-side surface of the fourth lens thereof is a concave surface;
a fifth lens with a refractive power;
a sixth lens with a refractive power, an image-side surface of the sixth lens thereof is a concave surface; and
a seventh lens with a negative refractive power, an object-side surface of the seventh lens is a convex surface and an image-side surface of the seventh lens is a concave surface;
wherein a maximum field of view FOV of the optical imaging lens group and an effective focal length f of the optical imaging lens group satisfy tan(FOV/2)*f>5 mm; and
a curvature radius R12 of the image-side surface of the sixth lens and a curvature radius R14 of an image-side surface of the seventh lens satisfy 1<R12/R14<2;
a curvature radius R2 of an image-side surface of the first lens, a curvature radius R3 of an object-side surface of the second lens, and a spacing distance T12 between the first lens and the second lens on the optical axis satisfy |R2−R3|/T12≤3.92;
an effective focal length f6 of the sixth lens and an effective focal length f7 of the seventh lens satisfy −2<f6/f7<−1.
2. The optical imaging lens group according to claim 1 , wherein the optical imaging lens group is arranged on an electronic photosensitive element, and ImgH is a half of a diagonal length of an effective pixel region of the electronic photosensitive element, and a spacing distance TTL from an object-side surface of the first lens to an imaging surface of the electronic photosensitive element on the optical axis and ImgH satisfy TTL/ImgH<1.5.
3. The optical imaging lens group according to claim 1 , wherein a curvature radius R11 of an object-side surface of the sixth lens and the effective focal length f of the optical imaging lens group satisfy R11/f<0.5.
4. The optical imaging lens group according to claim 1 , wherein a center thickness CT3 of the third lens on the optical axis and a center thickness CT4 of the fourth lens on the optical axis satisfy 100*|CT3−CT4<10.
5. The optical imaging lens group according to claim 1 , wherein a spacing distance T45 between the fourth lens and the fifth lens on the optical axis and a spacing distance T56 between the fifth lens and the sixth lens on the optical axis satisfy T45/T56<1.5.
6. The optical imaging lens group according to claim 1 , wherein an on-axis spacing distance SAG62 from an intersection point of the image-side surface of the sixth lens and the optical axis to an effective radius vertex of the image-side surface of the sixth lens and a center thickness CT6 of the sixth lens on the optical axis satisfy −1.5<SAG62/CT6<−0.9.
7. The optical imaging lens group according to claim 1 , wherein ImgH is a half of a diagonal length of an effective pixel region of the electronic photosensitive element, and an effective semi-diameter DT11 of an object-side surface of the first lens and ImgH satisfy DT11/ImgH<0.4.
8. The optical imaging lens group according to claim 1 , wherein an effective radius DT61 of an object-side surface of the sixth lens, an effective radius DT52 of an image-side surface of the fifth lens, an effective radius DT51 of an object-side surface of the fifth lens and an effective radius DT42 of the image-side surface of the fourth lens satisfy 2<(DT61−DT52)/(DT51−DT42)<20.
9. The optical imaging lens group according to claim 1 , wherein an edge thickness ET5 of the fifth lens and a center thickness CT5 of the fifth lens on the optical axis satisfy 0.8<ET5/CT5<1.2.
10. The optical imaging lens group according to claim 1 , wherein each of an object-side surface of the sixth lens and the image-side surface of the sixth lens has at least one critical point, and a vector height YT61 along the optical axis from the center of the object-side surface of the sixth lens to the critical point of the object-side surface of the sixth lens closest to the optical axis and a vector height YT62 along the optical axis from the center of the image-side surface of the sixth lens to the critical point of the image-side surface of the sixth lens closest to the optical axis satisfy 0.8<YT61/YT62<1.3.
11. The optical imaging lens group according to claim 1 , wherein a distance OT from a shot object to an object-side surface of the first lens on the optical axis and a spacing distance TTL from the object-side surface of the first lens to the imaging surface of an electronic photosensitive element on the optical axis satisfy OT/TTL<30.
12. The optical imaging lens group according to claim 1 , wherein an abbe number V3 of the third lens and an abbe number V4 of the fourth lens satisfy V3>V4.
13. The optical imaging lens group according to claim 1 , wherein a maximum distortion DISTmax of the optical imaging lens group satisfies 5%<|DISTmax|<50%.