MULTIFOCAL LENS WITH A DIFFRACTIVE OPTICAL POWER REGION

• US 20090046349A1
• Filed: 07/02/2008
• Published: 02/19/2009
• Est. Priority Date: 07/03/2007
• Status: Active Grant

• Current Assignee: Carl Zeiss Vision International GMBH (Carl-Zeiss-Stiftung)
• Original Assignee: Pixeloptics Incorporated
• Inventors: Blum, Ronald D., Clarke, Roger, Kokonaski, William, Haddock, Joshua N., Mattison-Shupnick, Mark
• Granted Patent: US 8,317,321 B2
• Time in Patent Office: Days
• US Class Current: 359/319
• CPC Class Codes: G02B 5/1895 such optical elements having dioptric power
• CPC Class Codes: G02C 2202/20 Diffractive and Fresnel lenses or lens portions
• CPC Class Codes: G02C 7/06 bifocal; multifocal ; progressive G02C7/041 takes precedence
• CPC Class Codes: G02C 7/061 Spectacle lenses with progressively varying focal power
• CPC Class Codes: G02C 7/083 Electrooptic lenses

Abstract

A lens system is presented having a diffractive optical power region. The diffractive optical power region has a plurality of concentric surface relief diffractive structures. A greater portion of light incident on a diffractive structure near the center point contributes to the optical power than light incident on a diffractive structure peripherally spaced therefrom.

Claims

5-1. The lens system of claim 1, wherein the fraction is non-zero at the peripheral edge of the diffractive optical power region.

13. A lens system comprising:

a diffractive optical power region comprising a plurality of concentric surface relief diffractive structures having a series of crests and adjacent troughs forming a sawtooth pattern, wherein each concentric surface relief diffractive structure extends from a trough to an adjacent crest of the sawtooth pattern, wherein the distance between a first crest and a first adjacent trough near the center point is greater than the distance between a second crest and a second adjacent trough spaced from the center point.

14. The lens system of claim 13, wherein the distances between the crests and troughs adjacent thereto are measured in an axis of rotational symmetry of the concentric surface relief diffractive structures.

15. The lens system of claim 13, wherein the distances between the crests and troughs adjacent thereto decrease monotonically as the distance of the diffractive structure increases from the center point.

16. The lens system of claim 13, wherein the distance between a crest and a trough adjacent thereto near a peripheral edge of the diffractive optical power region is approximately zero.

17. The lens system of claim 13, wherein the distances are scaled by a function having a range of from zero and one.

18. The lens system of claim 13, wherein the sawtooth pattern is approximated by a piecewise function.

19. The lens system of claim 13, wherein the optical power is constant.

20. The lens system of claim 13, wherein the optical power is progressive.

21. The lens system of claim 13, wherein the diffractive optical power region is cropped.

22. A lens system, comprising:

a diffractive optical power region having a center and a peripheral edge, wherein the diffractive optical power region focuses light to a focal point, wherein the amount of light focused on the focal point from the center is greater than the amount of light focused on the focal point from the peripheral edge.

23. The lens system of claim 22, wherein the amount of light focused on the focal point monotonically decreases as the distance increases from the center point.

24. The lens system of claim 22, wherein the amount of light focused on the focal point is scaled by a function having a range of from zero to one.

25. The lens system of claim 22, wherein the amount of light focused on the focal point is approximately zero at the peripheral edge of the diffractive optical power region.

26. The lens system of claim 22, wherein the amount of light focused on the focal point is non-zero at the peripheral edge of the diffractive optical power region.

27. The lens system of claim 22, wherein the diffractive optical power region is cropped.

28. The lens system of claim 22, wherein the lens system is static.

29. The lens system of claim 22, wherein the lens system is dynamic.

30. An electro-active lens system, comprising:

a controller for applying voltages;

a plurality of individually addressable electrodes electrically connected to the controller, and

electro-active material disposed between the individually addressable electrodes, wherein when the controller applies voltages to the plurality of individually addressable electrodes, the refractive index of electro-active material is altered to provide an optical power, wherein a greater portion of light incident near the geometric center of the plurality of individually addressable electrodes contributes to the optical power than light incident spaced from the geometric center of the plurality of individually addressable electrodes.

31. The electro-active lens system of claim 30, wherein the plurality of individually addressable electrodes are transparent.

32. The electro-active lens system of claim 30, wherein the electro-active material comprises cholesteric liquid crystal.

33. The electro-active lens system of claim 30, wherein the portion contributed to the optical power monotonically decreases as the radial distance from the geometric center of the individually addressable electrodes increases.

34. The electro-active lens system of claim 30, wherein the portion is scaled by a function having a range of from zero to one.

35. The electro-active lens system of claim 30, wherein the portion is approximately zero at the peripheral edge of the plurality of individually addressable electrodes.

36. The electro-active lens system of claim 30, wherein the portion is non-zero at the peripheral edge of the plurality of individually addressable electrodes.

37. The electro-active lens system of claim 30, wherein the optical power is constant.

38. The electro-active lens system of claim 30, wherein the optical power is progressive.

39. The electro-active lens system of claim 30, wherein the diffractive optical power region is cropped.

40. A lens system, comprising:

a diffractive optical power region comprising a first region having a plurality of concentric surface relief diffractive structures for focusing light of a specific wavelength λ

to a focal length f, wherein the radius of the n^th concentric surface relief diffractive structure from the center point is greater than √

{square root over (2nλ

f)}.

41. The lens system of claim 40, wherein the diffractive optical power region provides a progression of decreasing optical power.

42. The lens system of claim 40, wherein the diffractive optical power region further comprises a second region having a plurality of concentric surface relief diffractive structures, wherein the radius of the n^th concentric surface relief diffractive structure of the second region from the center point thereof is approximately equal to √

{square root over (2nλ

f)}.

43. The lens system of claim 42, wherein the second region provides a constant optical power.

44. The lens system of claim 40, wherein the second region is positioned radially interior to the first region.

45. The lens system of claim 40, wherein the radial widths of at least some of the surface relief diffractive structures of the first region are equal to one another.

46. A lens system, comprising:

a diffractive optical power region comprising a first region having a plurality of concentric surface relief diffractive structures for focusing light of a specific wavelength λ

to a focal length f, wherein the radius of the n^th concentric surface relief diffractive structure from the center point is less than √

{square root over (2nλ

f)}.

47. The lens system of claim 46, wherein the diffractive optical power region provides a progression of increasing optical power.

48. The lens system of claim 46, wherein the diffractive optical power region further comprises a second region having a plurality of concentric surface relief diffractive structures, wherein the radius of the n^th concentric surface relief diffractive structure of the second region from the center point thereof is approximately equal to √

{square root over (2nλ

f)}.

49. The lens system of claim 48, wherein the second region provides a constant optical power.

50. The lens system of claim 46, wherein the second region is positioned radially interior to the first region.

51. The lens system of claim 46, wherein the radial widths of at least some of the surface relief diffractive structures of the first region are equal to one another.