Optical apparatus with structure for liquid invariant performance

Patent metadata

Field	Value
Publication number	US-10031334-B2
Application number	US-201113578158-A
Country	US
Kind code	B2
Filing date	Feb 9, 2011
Priority date	Feb 9, 2010
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

A phase-adjusting element configured to provide substantially liquid-invariant extended depth of field for an associated optical lens. One example of a lens incorporating the phase-adjusting element includes the lens having surface with a modulated relief defining a plurality of regions including a first region and a second region, the first region having a depth relative to the second region, and a plurality of nanostructures formed in the first region. The depth of the first region and a spacing between adjacent nanostructures of the plurality of nanostructures is selected to provide a selected average index of refraction of the first region, and the spacing between adjacent nanostructures of the plurality of nanostructures is sufficiently small that the first region does not substantially diffract visible light.

First claim

The invention claimed is:

1. A lens comprising a surface having a surface relief comprising a plurality of regions including at least one pair of first and second adjacent regions, the first and second regions being configured to differently affect phase of light passing through said regions to thereby induce a desired phase difference and provide desired extension of a depth of field of the lens, wherein
the first region of the lens is recessed relative to the second region of the lens and has a depth in a range of 1 to 1.5 microns relative to the second region,
the first region comprises a plurality of structures including first structures extending outward from a base of the first region, wherein a height of the first structures is equal to the depth of the first region, the pattern of structures providing surface roughness in said first region to prevent liquid from entering said first region thereby maintaining said phase difference for light passing through the first and second regions.

2. The lens as claimed in claim 1 , wherein spacing between features of said pattern is sufficiently small to prevent liquid from penetrating between the features.

3. The lens as claimed in claim 1 , wherein the first region, being the region having said pattern defining the surface roughness, has a depth relative to the second region.

4. The lens as claimed in claim 3 , wherein the first region has certain average refractive index defined by said depth of the first region and density of features of said pattern within the first region.

5. The lens as claimed in claim 4 , wherein said pattern is in the form of an array of nanostructures extending away from the base of said region.

6. The lens as claimed in claim 3 , wherein a lateral width of the first region is large compared to wavelengths of visible light, such that the surface relief does not cause diffraction of light of the visible range.

7. The lens as claimed in claim 5 , wherein spacing between the features of the pattern is less than approximately a shortest wavelength of visible light in free space.

8. The lens as claimed in claim 5 , comprising second nanostructures of a height that is less than or equal to the depth of the first region.

9. The lens as claimed in claim 1 , wherein the first region has one of the following configurations: the first region is a circular region, the first region is an annular region, and the first region comprises a plurality of concentric zones.

10. The lens as claimed in claim 2 , wherein the pattern has one of the following arrangements of features: the features are equally spaced, or spacing between adjacent features decreases from a largest spacing at a center of the first region to smallest spacing at edges of the first region.

11. The lens as claimed in claim 5 , wherein the nanostructures are either uniformly spaced apart from one another, or are arranged with varying spacing between them such that spacing adjacent nanostructures decreases from a largest spacing at a center of the first region to smallest spacing at edges of the first region.

12. The lens as claimed in claim 1 , wherein the lens is an ophthalmic contact lens.

13. The lens as claimed in claim 12 , wherein said pattern is in the form of an array of nanostructures extending away from the base of the first region, spacing between the adjacent nanostructures being sufficiently small to prevent liquid from penetrating between the nanostructures at atmospheric pressure; the first region having a depth relative to the second region, the certain average refractive index of the first region being defined by said depth of the first region and by density of the nanostructures within the first region.

14. A lens having a depth of field, the lens comprising:
a phase-adjusting region formed in a lens surface of the lens, the phase-adjusting region extending into the lens and being recessed relative to the lens surface by a depth in a range of 1 to 1.5 microns and configured to extend the depth of field of the lens; and
a plurality of nanostructures disposed in the phase-adjusting region, the plurality of nanostructures extending away from a base of the phase-adjusting region, a height of first nanostructures of the plurality of nanostructures being equal to said depth of the phase-adjusting region.

15. The lens as claimed in claim 14 , wherein the nanostructures are of a height that is less than or equal to the depth of the phase-adjusting region.

16. The lens as claimed in claim 14 , wherein the phase-adjusting region comprises one or more a circular or annular regions.

17. The lens as claimed in claim 14 , further comprising:
at least one additional phase-adjusting region; and
at least one corresponding additional plurality of nanostructures formed in the at least one additional phase-adjusting region.

18. The lens as claimed in claim 14 , wherein the nanostructures are either uniformly spaced apart from one another, or the spacing between the adjacent nanostructures decreases from a largest spacing at a center of the phase-adjusting region to smallest spacing at edges of the phase-adjusting region.

19. The lens as claimed in claim 14 , wherein a density of the plurality of nanostructures and the depth of the phase-adjusting region are selected based at least in part on a predetermined desired average refractive index of the phase-adjusting region.

20. The lens as claimed in claim 14 , wherein the lens is an ophthalmic contact lens with the extended depth of field, where the plurality of nanostructures prevent liquid from entering the phase-adjusting region.

21. The lens as claimed in claim 14 , wherein a lateral width of the phase-adjusting region is large compared to wavelengths of visible light to prevent diffraction of light of the visible range.

22. An imaging apparatus comprising:
a lens; and
a phase-adjusting optical element associated with the lens and configured to extend a depth of field of the lens, the phase-adjusting optical element comprising a surface relief on the lens surface including at least one first region and at least one second region, the at least one first region being recessed relative to the at least one second region by a depth in the range of 1 to 1.5 microns and comprising a plurality of nanostructures extending away from a base of said first region, a height of first nanostructures of the plurality of nanostructures being equal to said depth of the first region.

23. The imaging apparatus as claimed in claim 22 , further comprising:
a detector optically coupled to the lens and configured to detect light passing through the lens; and
a processor coupled to the detector and configured to produce an image from the light detected by the detector.

24. The imaging apparatus as claimed in claim 22 , comprising second nanostructures of a height that is less than or equal to a depth of the at least one first region.

25. The imaging apparatus as claimed in claim 22 , wherein a density of the plurality of nanostructures and a depth of the at least one first region are selected based at least in part on a predetermined desired average refractive index of the at least one first region.

26. The imaging apparatus as claimed in claim 22 , wherein:
said surface relief on the lens defines a plurality of the recessed regions; and
a corresponding plurality of groups of the nanostructures, each group of the nanostructures formed in a respecti

Assignees

• Zalevsky Zeev
• Limon Ofer
• Holden Brien Vision Inst

Inventors

• Zalevsky Zeev
• Limon Ofer

Classifications

• G02B27/0037

  with diffracting elements (G02B27/0056 takes precedence; holographic optical elements G02B5/32; zone systems G02B5/1876) · CPC title

• G02B5/18

  Diffraction gratings {(holographic optical elements G02B5/32, G03H; integrally combined with optical fibres G02B6/02057; for coupling light guides G02B6/34; integrally combined with optical integrated light guides G02B6/12; grating systems G02B27/44)} · CPC title

• G02C7/06

  bifocal; multifocal {; progressive (G02C7/041 takes precedence)} · CPC title

• Y10S977/932

  for electronic or optoelectronic application · CPC title

• G02C7/049

  Contact lenses having special fitting or structural features achieved by special materials or material structures · CPC title