Wide angle lens and camera system for peripheral field of view imaging including eight lenses of ---++-++ or nine lenses of ----++-++ refractive powers
Wide angle lens for imaging objects disposed away from the optical axis towards the periphery of the field of view.
1. A wide angle lens having an angular field of view, FOV, of more than 150 degrees spanning an optical axis and a central half-field of view, FOV 1/2 , spanning the optical axis such that a ratio of the angular range FOV 1/2 of the central half field of view versus the angular range of the field of view FOV is FOV/FOV 1/2 =2, the lens being constructed and arranged such that a ratio of a diameter (D 1 ) at an image plane of an image circle of the field of view versus the diameter (D 1/2 ) of an image circle of the central half-field of view is D 1 /D 1/2 >2 and comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a longitudinal spherical aberration throughout the region of interest less than half of the longitudinal spherical aberration on-axis.
2. A wide angle lens of claim 1 wherein D 1 /D 1/2 ≥2.2.
3. The wide angle lens of claim 1 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein angular mapping of the field of view in the region of interest onto the image plane is substantially linear.
4. The wide angle lens of claim 1 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a field curvature for tangential rays on-axis greater than the field curvature for tangential rays throughout the region of interest.
5. The wide angle lens of claim 1 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a field curvature for tangential rays throughout the region of interest less than one quarter of the field curvature for tangential rays on-axis.
6. The wide angle lens of claim 1 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a modulation transfer function of at least 55% at 187 lp/mm for sagittal rays in the region of interest.
7. The wide angle lens of claim 1 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a modulation transfer function of at least 76% at 93 lp/mm for sagittal rays in the region of interest.
8. The wide angle lens of claim 1 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a modulation transfer function of at least 36% at 187 lp/mm for tangential rays in the region of interest.
9. The wide angle lens of claim 1 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a modulation transfer function of at least 65% at 93 lp/mm for tangential rays in the region of interest.
10. The wide angle lens of claim 1 , wherein the lens comprises all spherical surfaces.
11. The wide angle lens of claim 1 , wherein an effective focal length is 1 mm or less.
12. The wide angle lens of claim 1 , wherein an f-number is 2.4 or less.
13. The wide angle lens of claim 1 , wherein an f-theta distortion is 34% or less at full field.
14. The wide angle lens of claim 1 , wherein a chief ray angle at an image plane of the wide angle lens is less than 4.5 degrees from a normal to a surface at an image plane.
15. The wide angle lens of claim 1 , wherein a back focal length is 1 mm or less.
16. A wide angle lens having an angular field of view, FOV, of more than 150 degrees spanning an optical axis and a central half-field of view, FOV 1/2 , spanning the optical axis such that a ratio of the angular range FOV 1/2 of the central half field of view versus the angular range of the field of view FOV is FOV/FOV 1/2 =2, the lens being constructed and arranged such that a ratio of a diameter (D 1 ) at an image plane of an image circle of the field of view versus the diameter (D 1/2 ) of an image circle of the central half-field of view is D 1 /D 1/2 >2, wherein the full field of view spanning the optical axis is 200 degrees.
17. A camera system comprising the wide angle lens according to claim 16 and comprising an image sensor having an imaging surface area placed at the image plane.
18. A wide angle lens of claim 16 , wherein D 1 /D 1/2 ≥2.2.
19. A wide angle lens of claim 16 , wherein D 1 /D 1/2 ≥2.5.
20. A wide angle lens of claim 16 , wherein D 1 /D 1/2 ≥3.
21. The wide angle lens of claim 16 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein angular mapping of the field of view in the region of interest onto the image plane is substantially linear.
22. The wide angle lens of claim 16 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a longitudinal spherical aberration on-axis greater than the longitudinal spherical aberration throughout the region of interest.
23. The wide angle lens of claim 16 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a longitudinal spherical aberration throughout the region of interest less than half of the longitudinal spherical aberration on-axis.
24. The wide angle lens of claim 16 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a field curvature for tangential rays on-axis greater than the field curvature for tangential rays throughout the region of interest.
25. The wide angle lens of claim 16 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a field curvature for tangential rays throughout the region of interest less than one quarter of the field curvature for tangential rays on-axis.
26. The wide angle lens of claim 16 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a modulation transfer function of at least 55% at 187 lp/mm for sagittal rays in the region of interest.
27. The wide angle lens of claim 16 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a modulation transfer function of at least 76% at 93 lp/mm for sagittal rays in the region of interest.
28. The wide angle lens of claim 16 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a modulation transfer function of at least 36% at 187 lp/mm for tangential rays in the region of interest.
29. The wide angle lens of claim 16 , comprising a region of interest disposed between the FOV 1/2 and FOV, wherein the lens has a modulation transfer function of at least 65% at 93 lp/mm for tangential rays in the region of interest.
30. The wide angle lens of claim 16 , wherein the lens comprises all spherical surfaces.
31. The wide angle lens of claim 16 , wherein an effective focal length is 1 mm or less.
32. The wide angle lens of claim 16 , wherein an f-number is 2.4 or less.
33. The wide angle lens of claim 16 , wherein an f-theta distortion is 34% or less at full field.
34. The wide angle lens of claim 16 , wherein a chief ray angle at an image plane of the wide angle lens is less than 4.5 degrees from a normal to a surface at an image plane.
35. The wide angle lens of claim 16 , wherein a back focal length is 1 mm or less.
36. A camera system comprising the wide angle lens according to claim 1 and comprising an image sensor having an imaging surface area placed at the image plane.
37. A wide angle lens of claim 1 , wherein D 1 /D 1/2 ≥2.2.
38. A wide angle lens of claim 1 , wherein D 1 /D 1/2 ≥2.5.
39. A wide angle lens of claim 1 , wherein D 1 /D 1/2 ≥3.