ARRAY-BASED CAMERA LENS SYSTEM

• US 20170261651A1
• Filed: 11/17/2016
• Published: 09/14/2017
• Est. Priority Date: 03/08/2016
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Powell, Karlton D.
• Granted Patent: US 9,945,988 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 13/26 for reproducing with unit magnification
• CPC Class Codes: G02B 27/0075 with means for altering, e.g. increasing, the depth of field or depth of focus
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 3/0062 Stacked lens arrays, i.e. refractive surfaces arranged in at least two planes, without structurally separate optical elements in-between
• CPC Class Codes: G02B 3/0075 characterized by non-optical structures, e.g. having integrated holding or alignment means
• CPC Class Codes: G02B 30/56 by projecting aerial or floating images
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof

Abstract

A lens system includes a first lens array assembly including a first plurality of cells, each cell of the first plurality of cells configured to exhibit a pair of first Fourier transform lenses, and a second lens array assembly including a second plurality of cells, each cell of the second plurality of cells configured to exhibit a pair of second Fourier transform lenses. The first Fourier transform lenses have a first pitch. The second Fourier transform lenses have a second pitch differing from the first pitch. The first and second lens array assemblies are positioned relative to one another along an optical axis of the lens system such that a Fourier transform of light from an object is developed at a plane between the first and second lens array assemblies and an image of the object is provided at an image conjugate distance from the second lens array assembly.

Claims

1. A lens system comprising:

a first lens array assembly comprising a first plurality of cells, each cell of the first plurality of cells configured to exhibit a pair of first Fourier transform lenses; and

a second lens array assembly comprising a second plurality of cells, each cell of the second plurality of cells configured to exhibit a pair of second Fourier transform lenses;

wherein;

the first Fourier transform lenses have a first pitch;

the second Fourier transform lenses have a second pitch differing from the first pitch; and

the first and second lens array assemblies are positioned relative to one another along an optical axis of the lens system such that a representation of a Fourier transform of light from an object is developed at a plane between the first and second lens array assemblies and an image of the object is provided at an image conjugate distance from the second lens array assembly.

2. The lens system of claim 1, wherein:

the image conjugate distance is established via a function of an object conjugate distance for the object, a distance between the first and second lens array assemblies, the first and second pitches, a first focal length of the first plurality of cells, and a second focal length of the second plurality of cells; and

the function establishes that light emanating from the object and passing through the respective cells of the first and second plurality of cells converges at the image conjugate distance.

3. The lens system of claim 1, wherein the first and second lens array assemblies are spaced apart from one another by a gap.

4. The lens system of claim 3, further comprising a positioner coupled to the first lens array assembly, the second lens array assembly, or both the first and second lens array assemblies, the positioner being configured to adjust a size of the gap.

5. The lens system of claim 1, wherein:

the first lens array assembly comprises a first pair of in-tandem microlens arrays, each microlens array of the first pair comprising a respective set of constituent lenslets having the first pitch, each constituent lenslet having a first common focal length;

the second lens array assembly comprises a second pair of in-tandem microlens arrays, each microlens array of the second pair comprising a respective set of constituent lenslets having the second pitch, each constituent lenslet having a second common focal length;

the in-tandem microlens arrays of the first pair are separated from one another along an optical axis of the lens system by the first common focal length;

the in-tandem microlens arrays of the second pair are separated from one another along the optical axis of the lens system by the second common focal length; and

the first and second pairs of in-tandem microlens arrays are positioned relative to one another along the optical axis such that the image is provided at the image conjugate distance.

6. The lens system of claim 5, wherein one or more of the respective sets of constituent lenslets exhibits lenslet-by-lenslet variance within the respective set of constituent lenslets.

7. The lens system of claim 6, wherein the lenslet-by-lenslet variance is a lenslet profile variance.

8. The lens system of claim 1, further comprising an image sensor disposed at the image conjugate distance.

9. The lens system of claim 8, further comprising a positioner configured to adjust a position of the image sensor to dispose the image sensor at the image conjugate distance.

10. The lens system of claim 1, wherein:

the first lens array assembly comprises a first array of graded-index microlensing structures;

each graded-index microlensing structure of the first array corresponds with a respective one of the first plurality of cells;

the second lens array assembly comprises a second array of graded-index microlensing structures; and

each graded-index microlensing structure of the second array corresponds with a respective one of the second plurality of cells.

11. A lens system comprising:

a first pair of in-tandem microlens arrays, each microlens array of the first pair comprising a respective set of lenslets, each lenslet having a first common focal length;

a second pair of in-tandem microlens arrays, each microlens array of the second pair comprising a respective set of lenslets, each lenslet having a second common focal length, the first and second pairs of in-tandem microlens arrays separated from one another along an optical axis of the lens system by a gap; and

a positioner coupled to one or both of the first pair and second pair, the positioner configured to adjust a size of the gap;

wherein;

the in-tandem microlens arrays of the first pair are separated from one another along the optical axis by the first common focal length such that the microlens arrays of the first pair are configured to provide a representation of a Fourier transform of light emanating from an object, the representation provided along a plane disposed in the gap;

the in-tandem microlens arrays of the second pair are separated from one another along the optical axis of the lens system by the second common focal length such that the microlens arrays of the second pair are configured to provide an image of the object via Fourier transformation of the representation; and

the in-tandem microlens arrays of the first pair, the second pair, or both the first and second pairs, have different pitches.

12. The lens system of claim 11, wherein one or more of the microlens arrays exhibits lenslet-by-lenslet variance.

13. The lens system of claim 12, wherein the lenslet-by-lenslet variance is a lenslet profile variance.

14. The lens system of claim 11, wherein respective pitches of the in-tandem microlens arrays of the first pair have respective pitches that differ from respective pitches of the in-tandem microlens arrays.

15. The lens system of claim 11, further comprising an aperture array embedded in one of the in-tandem microlens arrays of one or more of the first pair and the second pair.

16. The lens system of claim 11, wherein one or more of the microlens arrays is configured for flip-and-stitch propagation of the light emanating from the object.

17. A camera comprising:

a first pair of in-tandem microlens arrays, each microlens array of the first pair comprising a respective set of lenslets, each lenslet having a first common focal length;

a second pair of in-tandem microlens arrays, each microlens array of the second pair comprising a respective set of lenslets, each lenslet having a second common focal length, the first and second pairs of in-tandem microlens arrays separated from one another by a gap;

an image sensor disposed at an image conjugate distance from the second pair of in-tandem microlens arrays; and

a positioner coupled to, and configured to adjust a position of, one or more of the first pair, the second pair, and the image sensor;

wherein;

the in-tandem microlens arrays of the first pair are separated from one another by the first common focal length such that the microlens arrays of the first pair are configured to provide a representation of a Fourier transform of light emanating from an object, the representation provided along a plane disposed in the gap;

the in-tandem microlens arrays of the second pair are separated from one another by the second common focal length such that the microlens arrays of the second pair are configured to provide an image of the object via Fourier transformation of the representation;

the first and second pairs of in-tandem microlens arrays are positioned relative to one another such that the image of the object is provided at an image conjugate distance from the second pair of in-tandem microlens arrays; and

at least two of the microlens arrays of the first pair and the second pair have different pitches.

18. The lens system of claim 17, wherein the image conjugate distance is established via a function of an object conjugate distance for the object, a distance between the first and second pairs, the first and second common focal lengths, the pitches of the in-tandem microlens arrays of the first and second pairs.

19. The lens system of claim 17, wherein all of the microlens arrays of the first and second pairs have different pitches from one another.

20. The lens system of claim 17, wherein one or more of the microlens arrays exhibits lenslet-by-lenslet profile variance.