Optical imaging system
An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially disposed in numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging plane of the optical imaging system, wherein the first to seventh lenses are spaced apart from each other along the optical axis, and the optical imaging system satisfies 0.1<L1w/L7w<0.4, where L1w is a weight of the first lens, L7w is a weight of the seventh lens, and L1w and L7w are expressed in a same unit of measurement.
1. An optical imaging system comprising:
a first lens having positive refractive power and comprising a convex object-side surface and a concave image-side surface, a second lens having negative refractive power and comprising a convex object-side surface and a concave image-side surface, a third lens having negative refractive power, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially disposed in numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging plane of the optical imaging system,
wherein the first to seventh lenses are spaced apart from each other along the optical axis, and
wherein the optical imaging system satisfies 0.01<R1/R4<1.3, where R1 is a radius of curvature of the object-side surface of the first lens, R4 is a radius of curvature of the image-side surface of the second lens, and R1 and R4 are expressed in a same unit of measurement.
2. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.1<L1w/L7w<0.3, where L1w is a weight of the first lens, L7w is a weight of the seventh lens, and L1w and L7w are expressed in a same unit of measurement.
3. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.1<R1/R5<0.7, where R5 is a radius of curvature of an object-side surface of the third lens, and R1 and R5 are expressed in a same unit of measurement.
4. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.05<R1/R6<0.9, where R6 is a radius of curvature of an image-side surface of the third lens, and R1 and R6 are expressed in a same unit of measurement.
5. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.2<R1/R11<1.2, where R11 is a radius of curvature of an object-side surface of the sixth lens, and R1 and R11 are expressed in a same unit of measurement.
6. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.8<R1/R14<1.2, where R14 is a radius of curvature of an image-side surface of the seventh lens, and R1 and R14 are expressed in a same unit of measurement.
7. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.6<(R11+R14)/(2*R1)<3.0, where R11 is a radius of curvature of an object-side surface of the sixth lens, R14 is a radius of curvature of an image-side surface of the seventh lens, and R1,R11, and R14 are expressed in a same unit of measurement.
8. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.1<(R11+R14)/(R5+R6)<1.0, where R5 is a radius of curvature of an object-side surface of the third lens, R6 is a radius of curvature of an image-side surface of the third lens, R11 is a radius of curvature of an object-side surface of the sixth lens, R14 is a radius of curvature of an image-side surface of the seventh lens, and R5, R6, R11, and R14 are expressed in a same unit of measurement.
9. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.4<D13/D57<1.2, where D13 is a distance along the optical axis from an object-side surface of the first lens to an image-side surface of the third lens, D57 is a distance along the optical axis from an object-side surface of the fifth lens to an image-side surface of the seventh lens, and D13 and D57 are expressed in a same unit of measurement.
10. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.1<(1/f1+1/f2+1/f3+1/f4+1/f5+1/f6+1/f7)*f<0.8, where f1 is a focal length of the first lens, f2 is a focal length of the second lens, f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, f5 is a focal length of the fifth lens, f6 is a focal length of the sixth lens, f7 is a focal length of the seventh lens, f is an overall focal length of the optical imaging system, and f1, f2, f3, f4, f5, f6, f7, and f are expressed in a same unit of measurement.
11. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.1<(1/f1+1/f2+1/f3+1/f4+1/f5+1/f6+1/f7)*TTL<1.0, where f1 is a focal length of the first lens, f2 is a focal length of the second lens, f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, f5 is a focal length of the fifth lens, f6 is a focal length of the sixth lens, f7 is a focal length of the seventh lens, TTL is a distance along the optical axis from an object-side surface of the first lens to the imaging plane, and f1, f2, f3, f4, f5, f6, f7, and TTL are expressed in a same unit of measurement.
12. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.2<TD1/D67<0.8, where TD1 is a thickness along the optical axis of the first lens, D67 is a distance along the optical axis from an object-side surface of the sixth lens to an image-side surface of the seventh lens, and TD1 and D67 are expressed in a same unit of measurement.
13. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies SD12<SD34, where SD12 is a distance along the optical axis from an image-side surface of the first lens to an object-side surface of the second lens, SD34 is a distance along the optical axis from an image-side surface of the third lens to an object-side surface of the fourth lens, and SD12 and SD34 are expressed in a same unit of measurement.
14. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies SD56<SD34, where SD34 is a distance along the optical axis from an image-side surface of the third lens to an object-side surface of the fourth lens, SD56 is a distance along the optical axis from an image-side surface of the fifth lens to an object-side surface of the sixth lens, and SD34 and SD56 are expressed in a same unit of measurement.
15. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies SD56<SD67, where SD56 is a distance along the optical axis from an image-side surface of the fifth lens to an object-side surface of the sixth lens, SD67 is a distance along the optical axis from an image-side surface of the sixth lens to an object-side surface of the seventh lens, and SD56 and SD67 are expressed in a same unit of measurement.
16. The optical imaging system of claim 1 , wherein the imaging plane is an imaging plane of an image sensor, and
the optical imaging system further satisfies 0.6<TTL/(2*IMG HT)<0.9, where TTL is a distance along the optical axis from an object-side surface of the first lens to the imaging plane of the image sensor, IMG HT is one-half of a diagonal length of the imaging plane of the image sensor, and TTL and IMG HT are expressed in a same unit of measurement.
17. The optical imaging system of claim 16 , wherein the optical imaging system further satisfies TTL≤6.00 mm, where TTL is expressed in mm.
18. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.2<ΣSD/ΣTD<0.7, where ΣSD is a sum of air gaps along the optical axis between the first to seventh lenses, ΣTD is a sum of thicknesses along the optical axis of the first to seventh lenses, and ΣSD and ΣTD are expressed in a same unit of measurement.
19. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0<min(f1:f3)/max(f4:f7)<0.4, where min(f1:f3) is a minimum value of absolute values of focal lengths of the first to third lenses, max(f4:f7) is a maximum value of absolute values of focal lengths of the fourth to seventh lenses, and min(f1:f3) and max(f4:f7) are expressed in a same unit of measurement.
20. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.4<ΣTD/TTL<0.7, where ΣTD is a sum of thicknesses along the optical axis of the first to seventh lenses, TTL is a distance along the optical axis from an object-side surface of the first lens to the imaging plane, and ΣTD and TTL are expressed in a same unit of measurement.
21. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.81<f12/f123<0.96, where f12 is a composite focal length of the first and second lenses, f123 is a composite focal length of the first to third lenses, and f12 and f123 are expressed in a same unit of measurement.
22. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.6<f12/f1234<0.84, where f12 is a composite focal length of the first and second lenses, f1234 is a composite focal length of the first to fourth lenses, and f12 and f1234 are expressed in a same unit of measurement.
23. The optical imaging system of claim 1 , wherein the fifth lens has a negative refractive power.
24. The optical imaging system of claim 23 , wherein a paraxial region of an object-side surface of the fifth lens is convex.
25. The optical imaging system of claim 23 , wherein a paraxial region of an image-side surface of the fifth lens is concave.
26. The optical imaging system of claim 1 , wherein a paraxial region of an object-side surface of the sixth lens is convex.
27. The optical imaging system of claim 26 , wherein a paraxial region of an image-side surface of the sixth lens is concave.
28. The optical imaging system of claim 1 , wherein a paraxial region of an object-side surface of the seventh lens is concave.
29. The optical imaging system of claim 1 , further comprising a spacer disposed between the sixth and seventh lenses,
wherein the optical imaging system further satisfies 0.5<S6d/f<1.2, where S6d is an inner diameter of the spacer, f is an overall focal length of the optical imaging system, and S6d and f are expressed in a same unit of measurement.
30. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.4<L1TR/L7TR<0.7, where L1TR is an overall outer diameter of the first lens, L7TR is an overall outer diameter of the seventh lens, and L1TR and L7TR are expressed in a same unit of measurement.
31. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.5<L1234TRavg/L7TR<0.75, where L1234TRavg is an average value of overall outer diameters of the first to fourth lenses, L7TR is an overall outer diameter of the seventh lens, and L1234TRavg and L7TR are expressed in a same unit of measurement.
32. The optical imaging system of claim 1 , wherein the optical imaging system further satisfies 0.5<L12345TRavg/L7TR<0.76, where L12345TRavg is an average value of overall outer diameters of the first to fifth lenses, L7TR is an overall outer diameter of the seventh lens, and L12345TRavg and L7TR are expressed in a same unit of measurement.