Data storage devices and methods
View Patent ↗A data storage device including: a plastic substrate having a plurality of volumes arranged in tracks along a plurality of vertically stacked, laterally extending layers therein; and, a plurality of micro-holograms each contained in a corresponding one of the volumes; herein, the presence or absence of a micro-hologram in each of the volumes is indicative of a corresponding portion of data stored.
1. A data storage device comprising:
a moldable non-photopolymer plastic substrate having a plurality of volumes arranged along tracks in a plurality of vertically stacked, laterally extending layers; and,
a plurality of micro-holograms each contained in a corresponding one of said volumes;
wherein, the presence or absence of a micro-hologram in each of said volumes is indicative of a corresponding portion of data stored.
2. The device of claim 1 , wherein said substrate is an about 120 mm diameter disc.
3. The device of claim 1 , wherein the substrate comprises a thermoplastic.
4. The device of claim 3 , wherein the substrate has a non-linear functional characteristic.
5. The device of claim 3 , wherein the substrate further comprises a thermal catalyst.
6. The device of claim 1 , wherein said substrate comprises a dye.
7. The device of claim 6 , wherein said dye is a reverse saturable absorber dye.
8. The device of claim 1 , wherein the substrate comprises a poly(ethylene oxide)/polystyrene block copolymer.
9. The device of claim 1 , wherein said substrate comprises a polycarbonate/polyester block copolymer.
10. The device of claim 1 , wherein said substrate comprises an ortho-nitrostilbene containing polymer.
11. The device of claim 1 , wherein said substrate comprises ortho-nitrostilbene and polymethylmethacrylate.
12. The device of claim 1 , wherein said substrate comprises polycarbonate.
13. The device of claim 1 , wherein said micro-holograms are substantially circular.
14. The device of claim 1 , wherein said micro-holograms are oblong.
15. The device of claim 1 , wherein said substrate is a disc having a center, at least one of said layers spirals toward said disc center, and at least one other of said layers spirals from said disc center.
16. The device of claim 1 , wherein each of said layers has a starting and ending point, and at least one of said starting points is substantially vertically aligned with at least one of said ending points.
17. The device of claim 1 , further comprising a second plurality of micro-holograms in said substrate and indicative of tracking information.
18. The device of claim 17 , wherein each of said data indicative and second plurality of micro-holograms has an axis, and the axis of said data indicative micro-holograms is distinct from the axis of said second plurality of micro-holograms.
19. The device of claim 18 , wherein an angle associated with the axis of a given one of said second plurality of micro-holograms is indicative the position thereof in the substrate.
20. A data storage device comprising:
a non-photopolymer plastic substrate having a threshold functional characteristic and a plurality of volumes arranged along tracks in a plurality of vertically stacked, laterally extending layers; and,
a plurality of micro-holograms each substantially contained in a corresponding one of said volumes;
wherein, the presence or absence of a micro-hologram in each of said volumes is indicative of a corresponding portion of data stored.
21. A method for storing data comprising:
providing a plastic substrate having a plurality of volumes arranged along tracks in a plurality of vertically stacked, laterally extending layers; and,
forming a plurality of micro-holograms in said substrate using a single exposure to a substantially single wavelength optical energy;
wherein, each of said micro-holograms is substantially contained in a corresponding one of said volumes and the presence or absence of a micro-hologram in each of said volumes is indicative of a corresponding portion of the data.
22. The method of claim 21 , wherein said micro-holograms are selectively formed dependently upon the data.
23. The method of claim 21 , further comprising selectively erasing select ones of the micro-holograms dependently upon the data.
24. The method of claim 21 , wherein said forming comprises interfering two counter-propagating light beams.
25. The method of claim 24 , further comprising focusing one of said light beams.
26. The method of claim 25 , further comprising reflecting one of said light beams to provide the other of said light beams.
27. The method of claim 24 , further comprising selectively obscuring at least one of the light beams dependently upon the data.
28. The method of claim 21 , further comprising forming a second plurality of holograms having a reflection direction distinct from that of said plurality of holograms.
29. The method of claim 28 , wherein said second plurality of holograms define said tracks.
30. The method of claim 21 , further comprising forming a second plurality of micro-holograms at a given spacing, wherein the spacing is indicative of the position within the substrate thereof.
31. The method of claim 21 , further comprising forming a second plurality of micro-holograms, wherein at least one of said second plurality of micro-holograms is co-located in a common one of the volumes with at least one of the plurality of micro-holograms.
32. The method of claim 21 , further comprising flood illuminating said micro-holograms through a second plastic substrate.
33. The method of claim 32 , wherein said illuminating induces a pattern of refractive index changes in said second plastic substrate.
34. The method of claim 33 , further comprising flood illuminating said second plastic substrate through a third plastic substrate.
35. The method of claim 34 , wherein said illuminating said second plastic substrate through a third plastic substrate duplicates said plurality of micro-holograms in said third substrate.
36. The method of claim 35 , wherein said flood illuminations use laser beams.
37. The method of claim 36 , wherein said laser beams have a central wavelength corresponding to said micro-holograms.
38. The method of claim 37 , wherein said central wavelength is about 532 nm.
39. A method for storing data comprising:
providing a plastic substrate having a plurality of volumes arranged along tracks in a plurality of vertically stacked, laterally extending layers; and,
interfering two counter-propagating light beams in said substrate, thereby forming a plurality of micro-holograms in said substrate,
wherein one of said beams is divergent and the other of the beams is focused where they interfere, a nd each of said micro-holograms is substantially contained in a corresponding one of said volumes and the presence or absence of a micro-hologram in each of said volumes is indicative of a corresponding portion of the data.
40. The method of claim 39 , wherein the focused one of the beams has a smaller spot size and larger power density than the divergent one of the beams where they interfere within the volumes and form the micro-holograms.