Optical assembly including plenoptic microlens array

Patent metadata

Field	Value
Publication number	US-9305956-B2
Application number	US-201514871703-A
Country	US
Kind code	B2
Filing date	Sep 30, 2015
Priority date	Aug 1, 2011
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

An optical assembly includes a solid spacing layer between a plenoptic microlens array (MLA) and a pixel-level MLA, avoiding the need for an air gap. Such an assembly, and systems and methods for manufacturing same, can yield improved reliability and efficiency of production, and can avoid many of the problems associated with prior art approaches. In at least one embodiment, the plenoptic MLA, the spacing layer, and the pixel-level MLA are created from optically transmissive polymer(s) deposited on the photosensor array and shaped using photolithographic techniques. Such an approach improves precision in placement and dimensions, and avoids other problems associated with conventional polymer-on-glass architectures. Further variations and techniques are described.

First claim

What is claimed is:

1. An optical assembly, comprising:
a photosensor array, comprising a plurality of photosensors;
a spacing layer, comprising a solid optically transmissive material, adjoining the photosensor array; and
a plenoptic microlens array adjoining the spacing layer, configured to direct incoming light through the spacing layer and toward the photosensor array, the plenoptic microlens array having a top surface and a bottom surface;
wherein the spacing layer is situated between the photosensor array and the plenoptic microlens array and is configured to separate the photosensor array from the plenoptic microlens array.

2. The optical assembly of claim 1 , wherein the plenoptic microlens array is created using photolithography.

3. The optical assembly of claim 1 , wherein the plenoptic microlens array is created by stamping and curing.

4. The optical assembly of claim 1 , wherein the spacing layer and the plenoptic microlens array are created as successive photolithographically deposited layers.

5. The optical assembly of claim 1 , wherein the spacing layer and the plenoptic microlens array are created from the same material.

6. The optical assembly of claim 1 , wherein the spacing layer and the plenoptic microlens array are created from the same photolithographically deposited layer.

7. The optical assembly of claim 1 , wherein the plenoptic microlens array comprises a plurality of plano-convex microlenses, each plano-convex microlens comprising:
a flat surface abutting the spacing layer; and
a convex surface.

8. The optical assembly of claim 1 , wherein the spacing layer and the plenoptic microlens array are created using photoresist.

9. The optical assembly of claim 1 , wherein the plenoptic microlens array comprises a plurality of layers of microlenses.

10. The optical assembly of claim 1 , wherein the plenoptic microlens array comprises a plurality of microlenses, wherein each microlens corresponds to an integral number of photosensors of the photosensor array.

11. The optical assembly of claim 1 , wherein the plenoptic microlens array comprises a plurality of microlenses, wherein each microlens corresponds to a square comprising an integral number of photosensors of the photosensor array.

12. The optical assembly of claim 1 , wherein the spacing layer adjoins the bottom surface of the plenoptic microlens array.

13. An optical assembly, comprising:
a photosensor array, comprising a plurality of photosensors;
a planarization layer adjoining the photosensor array, the planarization layer having a top surface and a bottom surface;
a spacing layer, comprising a solid optically transmissive material, adjoining the top surface of the planarization layer; and
a plenoptic microlens array adjoining the spacing layer, configured to direct incoming light through the spacing layer and toward the photosensor array, the plenoptic microlens array having a top surface and a bottom surface;
wherein the spacing layer is situated between the planarization layer and the plenoptic microlens array and is configured to separate the planarization layer from the plenoptic microlens array.

14. The optical assembly of claim 13 , wherein:
the spacing layer and the plenoptic microlens array are created from a material having a first index of refraction; and
the planarization layer is created from a material having a second index of refraction different from the first index of refraction.

15. The optical assembly of claim 13 , wherein:
the spacing layer and the plenoptic microlens array are created using photoresist; and
the planarization layer is created using silicon dioxide.

16. The optical assembly of claim 13 , wherein the spacing layer adjoins the bottom surface of the plenoptic microlens array.

17. A method for manufacturing an optical assembly, comprising:
adding a spacing layer to a photosensor array comprising a plurality of photosensors, the spacing layer comprising a solid optically transmissive material, adjoining the photosensor array; and
adding a plenoptic microlens array adjoining the spacing layer, configured to direct incoming light through the spacing layer and toward the photosensor array, the plenoptic microlens array having a top surface and a bottom surface;
wherein the spacing layer is added in such a manner as to be situated between the photosensor array and the plenoptic microlens array and configured to separate the photosensor array from the plenoptic microlens array.

18. The method of claim 17 , wherein the plenoptic microlens array is added using photolithography.

19. The method of claim 17 , wherein adding the spacing layer and adding the plenoptic microlens array comprise adding successive photolithographically deposited layers.

20. The method of claim 17 , wherein the spacing layer and the plenoptic microlens array are created from the same material.

21. The method of claim 17 , wherein the spacing layer and the plenoptic microlens array are created from the same photolithographically deposited layer.

22. The method of claim 17 , wherein adding the plenoptic microlens array comprises adding a plurality of plano-convex microlenses, each plano-convex microlens comprising:
a flat surface abutting the spacing layer; and
a convex surface.

23. The method of claim 17 , wherein adding the spacing layer and the plenoptic microlens array comprise creating the spacing layer and the plenoptic microlens array using photoresist.

24. The method of claim 17 , wherein adding the plenoptic microlens array comprises adding a plurality of layers of microlenses.

25. The method of claim 17 , wherein the spacing layer adjoins the bottom surface of the plenoptic microlens array.

26. The method of claim 17 , wherein adding the plenoptic microlens array comprises adding a plurality of microlenses, wherein each microlens corresponds to an integral number of photosensors of the photosensor array.

27. The method of claim 17 , wherein adding the plenoptic microlens array comprises adding a plurality of microlenses, wherein each microlens corresponds to a square comprising an integral number of photosensors of the photosensor array.

28. The method of claim 17 , wherein adding the plenoptic microlens array comprises:
stamping the plenoptic microlens array; and
curing the plenoptic microlens array.

29. The method of claim 28 , wherein:
stamping the plenoptic microlens array comprises stamping the plenoptic microlens array using a light-transmissive stamp; and
curing the plenoptic microlens array comprises curing the plenoptic microlens array through the light-transmissive stamp.

30. A method for manufacturing an optical assembly, comprising:
adding a planarization layer to a photosensor array comprising a plurality of photosensors, the planarization layer adjoining the photosensor array, the planarization layer having a top surface and a bottom surface;
adding a spacing layer, comprising a solid optically transmissive material, adjoining the top surface of the planarization layer; and
adding a plenoptic microlens array adjoining the spacing layer, configured to direct incoming light through the spacing layer and toward the photosensor array, the plenoptic microlens array having a top surface and a bottom surface;
wherein the spacing layer is situated between the planarization layer and the

Assignees

• Lytro Inc

Inventors

• Pitts Colvin
• Ng Yi-Ren
• Oliver Steven

Classifications

• G02B13/0085

  employing wafer level optics · CPC title

• H04N13/229

  using lenticular lenses, e.g. arrangements of cylindrical lenses · CPC title

• G02B3/0031

  Replication or moulding, e.g. hot embossing, UV-casting, injection moulding · CPC title

• G02B3/0068

  arranged in a single integral body or plate, e.g. laminates or hybrid structures with other optical elements (G02B5/1885, G02B17/002, G02B30/27 take precedence) · CPC title

• B29D11/00807

  Producing lenses combined with electronics, e.g. chips · CPC title