Microlens sheets having multiple interspersed anamorphic microlens arrays
View Patent ↗Microlens sheets include a first array of anamorphic micolenses on a face of a substrate. The microlenses in the first array are defined by a first parametric model along a direction of the first array. A second array of anamorphic micolenses is also provided on the face of the substrate, and interspersed with the first array. The microlenses in the second array are defined by a second parametric model that is different from the first parametric model, along the direction of the first array.
1. A microlens sheet comprising:
a substrate having first and second opposing faces;
a first array of anamorphic non-lenticular microlenses on the first face, the microlenses in the first array being defined by a first nonrandom parametric model along a direction of the first array; and
a second array of anamorphic non-lenticular microlenses on the first face and interspersed with the first array, the microlenses in the second array being defined by a second nonrandom parametric model that is different from the first nonrandom parametric model, along the direction of the first array.
2. A microlens sheet according to claim 1 wherein the microlenses in the first array are defined by a first constant and/or variable nonrandom parametric model along the direction of the first array, and the microlenses in the second array are defined by a second different constant and/or variable nonrandom parametric model along the direction of the first array.
3. A microlens sheet according to claim 1 wherein the direction is a horizontal direction, wherein the first array is also defined by a third parametric model along a vertical direction of the first array and wherein the second array is also defined by a fourth parametric model that is different from the third parametric model, along the vertical direction of the first array.
4. A microlens sheet according to claim 3 wherein the first array is defined by a third constant and/or variable parametric model along the vertical direction of the first array and wherein the second array is defined by a fourth constant and/or variable parametric model along the vertical direction of the first array.
5. A microlens sheet according to claim 4 wherein the third and fourth parametric models comprise constant and/or variable nonrandom parametric models.
6. A microlens sheet according to claim 3 wherein the first array includes a narrower base along the horizontal direction than along the vertical direction.
7. A microlens sheet according to claim 3 wherein the first through fourth parametric models are different constant and/or variable parametric models from one another.
8. A microlens sheet according to claim 7 wherein the variable parametric models comprise variable nonrandom parametric models.
9. A microlens sheet according to claim 3 wherein the substrate includes a periphery thereof and wherein the first and second arrays of anamorphic microlenses extend to the periphery of the substrate.
10. A microlens array according to claim 3 wherein the substrate includes a periphery thereof and wherein the microlens sheet further comprises a third array of microlenses on the first face adjacent the periphery and extending along the vertical direction that is not interspersed with the first and second arrays.
11. A microlens sheet according to claim 3 wherein the third and fourth parametric models comprise nonrandom parametric models.
12. A microlens sheet according to claim 1 wherein the substrate includes a periphery thereof and wherein the first and second arrays of anamorphic microlenses extend to the periphery of the substrate.
13. A microlens array according to claim 1 wherein the substrate includes a periphery thereof and wherein the microlens sheet further comprises a third array of microlenses on the first face adjacent the periphery that is not interspersed with the first and second arrays.
14. A microlens array according to claim 1 further comprising a masking layer on the second face and including an array of apertures therein.
15. A projection screen comprising a microlens sheet according to claim 1 .
16. A master comprising a replica of a microlens sheet according to claim 1 .
17. A stamper comprising an inverted replica of a microlens sheet according to claim 1 .
18. A microlens sheet according to claim 1 wherein the first parametric model produces a first full-width at half maximum (FWHM) angle and a first intensity distribution as a function of angle, and wherein the second parametric model produces a second FWHM angle that is different from the first FWHM angle and a second intensity distribution as a function of angle that is different from the first intensity distribution as a function of angle, the first and second arrays being interspersed so as to create a third FWHM angle for the microlens sheet that is different from the first and second FWHM angles and to create a third intensity distribution as a function of angle for the microlens sheet that is different from the first and second intensity distributions as a function of angle.
19. A microlens sheet according to claim 18 wherein the first and/or second intensity distributions are non-monotonic as a function of angle and wherein the third intensity distribution is monotonic as a function of angle.
20. A microlens sheet according to claim 19 wherein the third FWHM lies between the first and second FWHMs.
21. A microlens sheet according to claim 18 wherein the first and second arrays of microlenses are configured to produce an FWHM angle for the substrate of at least 60° and to produce a monotonically decreasing intensity distribution as a function of angle from 0° up to the half maximum angle.
22. A microlens sheet comprising:
a substrate having first and second opposing faces;
a first array of microlenses on the first face, the first array having a first full-width at half maximum (FWHM) angle and a first intensity distribution as a function of angle; and
a second array of microlenses on the first face and interspersed with the first array, the second array having a second FWHM angle that is different from the first FWHM angle and a second intensity distribution as a function of angle that is different from the first intensity distribution as a function of angle, the first and second arrays being interspersed so as to create a third FWHM angle for the microlens sheet that is different from the first and second FWHM angles and to create a third intensity distribution as a function of angle for the microlens sheet that is different from the first and second intensity distributions as a function of angle,
wherein the first and/or second intensity distributions are non-monotonic as a function of angle and the third intensity distribution is monotonic as a function of angle.
23. A microlens sheet according to claim 22 wherein the third FWHM lies between the first and second FWHMs.
24. A microlens array according to claim 22 wherein the first and second FWHM angles and the first and second intensity distributions as a function of angle are defined along a direction of the first array.
25. A microlens sheet according claim 24 wherein the microlenses in the first array are defined by a first parametric model along the direction of the first array, and wherein the microlenses in the second array are defined by a second parametric model that is different from the first parametric model, along the direction of the first array.
26. A microlens sheet according to claim 25 wherein the microlenses in the first array are defined by a first constant and/or variable parametric model along the direction of the first array, and the microlenses in the second array are defined by a second different constant and/or variable parametric model along the direction of the first array.
27. A microlens sheet according to claim 26 wherein the first and second parametric models comprise constant and/or variable nonrandom parametric models.
28. A microlens sheet according to claim 25 wherein the first and second parametric models comprise nonrandom parametric models.
29. A microlens array according to claim 22 further comprising a masking layer on the second face and including an array of apertures therein.
30. A projection screen comprising a microlens sheet according to claim 22 .
31. A master comprising a replica of a microlens sheet according to claim 22 .
32. A stamper comprising an inverted replica of a microlens sheet according to claim 22 .
33. A microlens sheet according to claim 22 wherein the third FWHM angle is at least 60° and wherein the third intensity distribution as a function of angle monotonically decreases as a function of angle from 0° up to the half maximum angle.
34. A microlens sheet according to claim 22 wherein the first and second parametric models comprise nonrandom parametric models.
35. A microlens sheet comprising:
a substrate having first and second opposing faces; and
a plurality of microlenses on the first face that are configured to produce a full-width at half maximum (FWHM) angle for the substrate of at least 60° and to produce a monotonically decreasing intensity distribution as a function of angle from 0° up to the half maximum angle.
36. A microlens sheet according to claim 35 wherein the substrate defines a horizontal direction and a vertical direction, and wherein the plurality of microlenses on the first face are configured to produce the FWHM angle for the substrate of at least 60° and to produce the monotonically decreasing intensity distribution as a function of angle from 0° up to the half maximum angle along the horizontal direction.
37. A microlens array according to claim 35 further comprising a masking layer on the second face and including an array of apertures therein.
38. A projection screen comprising a microlens sheet according to claim 35 .
39. A master comprising a replica of a microlens sheet according to claim 35 .
40. A stamper comprising an inverted replica of a microlens sheet according to claim 35 .