Optical assembly for a wide field of view point action camera with low field curvature

• US 10,107,989 B1
• Filed: 11/01/2016
• Issued: 10/23/2018
• Est. Priority Date: 03/16/2014
• Status: Active Grant

• Current Assignee: Navitar, Inc. (Ametek Incorporated)
• Original Assignee: Navitar Industries, LLC
• Inventors: Hudyma, Russell, Thomas, Michael
• Primary Examiner(s): Won, Bumsuk
• Assistant Examiner(s): Membrahtu, Ephrem
• Application Number:
  US15/340,960
• Time in Patent Office: 721 Days
• CPC Class Codes: G02B 13/0045 having five or more lenses
• CPC Class Codes: G02B 13/006 at least one element being a compound optical element, e.g. cemented elements
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G02B 13/18 with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration G02B13/002 takes precedence
• CPC Class Codes: G02B 27/0025 for optical correction, e.g. distorsion, aberration
• CPC Class Codes: G02B 5/005 Diaphragms for cameras G03B9/02
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation

Abstract

An optical assembly for a point action camera with a wide field of view includes multiple lens elements configured to provide a field of view in excess of 150 degrees. One or more lens elements has an aspheric surface. The optical assembly exhibits a low inward field curvature of less than 75 microns.

Claims

1. An optical assembly for a point action camera having a wide field of view, comprising multiple lens elements including an aspheric surface, configured to provide a field of view in excess of 150 degrees that comprises an inward field curvature of less than 75 microns,

wherein the optical assembly comprises from object end to image end a first optical group and a second optical group, wherein the first optical group is configured to collect light at said wide field of view and said second optical group is configured to compensate for distortion and astigmatism error, and

wherein said second optical group comprises multiple lens elements including an ultimate or penultimate lens element that is configured with an aspheric departure to compensate for said astigmatism error, and

wherein said optical assembly comprises seven lens elements;

wherein said optical assembly comprises a third optical group disposed between the first and second optical groups, and

wherein the third optical group comprises a biconvex lens.

2. The optical assembly of claim 1, wherein the inward field curvature comprises less than 60 microns.

3. The optical assembly of claim 1, wherein the inward field curvature comprises approximately 50 microns or less.

4. The optical assembly of claim 1, wherein the optical assembly has a longitudinal astigmatism that comprises approximately 0.7 mm or less.

5. The optical assembly of claim 1, wherein the optical assembly has a longitudinal astigmatism that comprises approximately 0.5 mm or less.

6. The optical assembly of claim 1, wherein the optical assembly has a longitudinal astigmatism that comprises approximately 0.3 mm or less.

7. The optical assembly of claim 1, wherein the optical assembly has a longitudinal astigmatism that approximately 0.2 mm or less.

8. The optical assembly of claim 1, wherein the optical assembly has a longitudinal astigmatism that comprises approximately 0.1 mm or less.

9. The optical assembly of claim 1, comprising an aperture stop between said first and second optical groups.

10. The optical assembly of claim 1, wherein said ultimate lens element comprises an aspheric lens surface.

11. The optical assembly of claim 10, wherein said ultimate lens element comprises an object facing side and an image facing side, and wherein said object facing side comprises said aspheric departure.

12. The optical assembly of claim 11, wherein the image facing side of said ultimate lens element comprises an aspheric lens surface.

13. The optical assembly of claim 10, wherein said ultimate lens element comprises an object facing side and an image facing side, and wherein said image facing side comprises said aspheric departure.

14. The optical assembly of claim 1, wherein said second optical group comprises four lens elements.

15. The optical assembly of claim 1, wherein said second optical group comprises from object side to image side, a first singlet, a doublet and a second singlet.

16. The optical assembly of claim 15, wherein said first singlet comprises a biconvex or plano-convex or quasi-plano-convex lens.

17. The optical assembly of claim 16, wherein said second singlet comprises a biconvex, or convexo-plano or convexo-quasi-plano lens.

18. The optical assembly of claim 17, wherein said first optical group comprises two or more convexo-concave or meniscus lenses.

19. The optical assembly of claim 16, wherein said doublet comprises, from object side to image side, a biconcave lens and a biconvex lens.

20. The optical assembly of claim 1, wherein the lateral chromatic aberration is less than approximately three pixels.

21. The optical assembly of claim 1, wherein the lateral chromatic aberration is less than approximately two pixels.

22. The optical assembly of claim 1, wherein the lateral chromatic aberration is less than approximately five microns.

23. The optical assembly of claim 1, wherein the lateral chromatic aberration is less than approximately three microns.

24. A digital camera, comprising

an optical assembly as in claim 1;

and

an image sensor disposed approximately at a focal plane of the optical assembly; and

a digital camera housing including electronics and a user interface, and containing said optical assembly and said image sensor in optically effective relative disposition.

25. The digital camera of claim 24, wherein the inward field curvature comprises less than 60 microns.

26. The digital camera of claim 24, wherein the inward field curvature comprises approximately 50 microns or less.

27. The digital camera of claim 24, wherein the optical assembly has a longitudinal astigmatism that comprises approximately 0.7 mm or less.

28. The digital camera of claim 24, wherein the optical assembly has a longitudinal astigmatism that comprises approximately 0.5 mm or less.

29. The digital camera of claim 24, wherein the optical assembly has a longitudinal astigmatism that comprises approximately 0.3 mm or less.

30. The digital camera of claim 24, wherein the optical assembly has a longitudinal astigmatism that approximately 0.2 mm or less.

31. The digital camera of claim 24, wherein the optical assembly has a longitudinal astigmatism that comprises approximately 0.1 mm or less.

32. The digital camera of claim 24, comprising an aperture stop between said first and second optical groups.

33. The digital camera of claim 32, wherein said ultimate lens element comprises said aspheric departure.

34. The digital camera of claim 33, wherein said ultimate lens element comprises an object facing side and an image facing side, and wherein said object facing side comprises said aspheric departure.

35. The optical assembly of claim 34, wherein the image facing side of said ultimate lens element comprises an aspheric lens surface.

36. The optical assembly of claim 33, wherein said ultimate lens element comprises an object facing side and an image facing side, and wherein said image facing side comprises said aspheric departure.

37. The digital camera of claim 24, wherein said second optical group comprises four lens elements.

38. The digital camera of claim 37, wherein said second optical group comprises from object side to image side, a first singlet, a doublet and a second singlet.

39. The digital camera of claim 38, wherein said first singlet comprises a biconvex or plano-convex or quasi-plano-convex lens.

40. The digital camera of claim 39, wherein said second singlet comprises a biconvex, or convexo-plano or convexo-quasi-plano lens.

41. The digital camera of claim 40, wherein said first optical group comprises two or more convexo-concave or meniscus lenses.

42. The digital camera of claim 38, wherein said doublet comprises, from object side to image side, a biconcave lens and a biconvex lens.

43. The digital camera of claim 24, wherein the lateral chromatic aberration is less than approximately three pixels.

44. The digital camera of claim 24, wherein the lateral chromatic aberration is less than approximately two pixels.

45. The digital camera of claim 24, wherein the lateral chromatic aberration is less than approximately five microns.

46. The digital camera of claim 24, wherein the lateral chromatic aberration is less than approximately three microns.

47. An optical assembly for a point action camera having a wide field of view, comprising multiple lens elements including an aspheric surface, configured to provide a field of view in excess of 150 degrees that comprises an inward field curvature of less than 75 microns,

wherein the optical assembly comprises from object end to image end a first optical group and a second optical group, wherein the first optical group is configured to collect light at said wide field of view and said second optical group is configured to compensate for distortion and astigmatism error, and

wherein said second optical group comprises multiple lens elements including an ultimate or penultimate lens element that is configured with an aspheric departure to compensate for said astigmatism error, and

wherein said optical assembly comprises seven lens elements,

wherein said second optical group comprises from object side to image side, a first singlet, a doublet and a second singlet,

wherein said first singlet comprises a biconvex or plano-convex or quasi-plano-convex lens,

wherein said second singlet comprises a biconvex, or convexo-plano or convexo-quasi-plano lens,

wherein said first optical group comprises two or more convexo-concave or meniscus lenses, and

wherein said first optical group further comprises a biconvex lens.

48. The optical assembly of claim 47, further comprising a third optical group disposed between the first and second optical groups.

49. The optical assembly of claim 48, wherein the third optical group comprises a biconvex lens.

50. A digital camera, comprising

an optical assembly as in claim 47;

and

an image sensor disposed approximately at a focal plane of the optical assembly; and

a digital camera housing including electronics and a user interface, and containing said optical assembly and said image sensor in optically effective relative disposition.

51. The digital camera of claim 50, comprising a third optical group disposed between the first and second optical groups.

52. The digital camera of claim 51, wherein the third optical group comprises a biconvex lens.

53. An optical assembly for a point action camera having a wide field of view, comprising multiple lens elements including an aspheric surface, configured to provide a field of view in excess of 150 degrees that comprises an inward field curvature of less than 75 microns,

wherein the optical assembly comprises from object end to image end a first optical group and a second optical group, wherein the first optical group is configured to collect light at said wide field of view and said second optical group is configured to compensate for distortion and astigmatism error, and

wherein said second optical group comprises multiple lens elements including an ultimate or penultimate lens element that is configured with an aspheric departure to compensate for said astigmatism error, and

wherein said optical assembly comprises seven lens elements,

wherein the optical assembly comprises a single aspheric lens element, which is the only aspheric lens element within the optical assembly.

54. The optical assembly of claim 53, wherein lens elements other than the single aspheric lens element comprise spherical or planar lens surfaces, or both, each without significant aspheric departures.

55. A digital camera, comprising

an optical assembly as in claim 53;

and

an image sensor disposed approximately at a focal plane of the optical assembly; and

a digital camera housing including electronics and a user interface, and containing said optical assembly and said image sensor in optically effective relative disposition.

56. The digital camera of claim 55, wherein lens elements other than the single aspheric lens element comprise spherical or planar lens surfaces, or both, each without significant aspheric departures.

57. An optical assembly for a point action camera having a wide field of view, comprising multiple lens elements including an aspheric surface, configured to provide a field of view in excess of 150 degrees that comprises an inward field curvature of less than 75 microns,

wherein the optical assembly comprises from object end to image end a first optical group and a second optical group, wherein the first optical group is configured to collect light at said wide field of view and said second optical group is configured to compensate for distortion and astigmatism error, and

wherein said second optical group comprises multiple lens elements including an ultimate or penultimate lens element that is configured with an aspheric departure to compensate for said astigmatism error, and

wherein said optical assembly comprises seven lens elements,

wherein the optical assembly comprises a single aspheric lens surface, which is the only aspheric lens surface within the optical assembly.

58. The optical assembly of claim 57, wherein the optical assembly comprises lens surfaces other than the single aspheric lens surface that comprise spherical or planar lens surfaces, or both, each without significant aspheric departures.

59. A digital camera, comprising

an optical assembly as in claim 57;

and

an image sensor disposed approximately at a focal plane of the optical assembly; and

a digital camera housing including electronics and a user interface, and containing said optical assembly and said image sensor in optically effective relative disposition.

60. The digital camera of claim 59, wherein the optical assembly comprises lens surfaces other than the single aspheric lens surface that comprise spherical or planar lens surfaces, or both, each without significant aspheric departures.