Augmented reality display having liquid crystal variable focus element and roll-to-roll method and apparatus for forming the same
View Patent ↗A display device includes a waveguide assembly comprising a waveguide configured to outcouple light out of a major surface of the waveguide to form an image in the eyes of a user. An adaptive lens assembly has a major surface facing the output surface and a waveplate lens and a switchable waveplate assembly. The switchable waveplate assembly includes quarter-wave plates on opposing sides of a switchable liquid crystal layer, and electrodes on the quarter-wave plates in the volume between the quarter-wave plates. The electrodes can selectively establish an electric field and may serve as an alignment structure for molecules of the liquid crystal layer. Portions of the adaptive lens assembly may be manufactured by roll-to-roll processing in which a substrate roll is unwound, and alignment layers and liquid crystal layers are formed on the substrate as it moves towards a second roller, to be wound on that second roller.
1. A display device comprising:
a waveguide assembly comprising a waveguide configured to output light to display an image; and
an adaptive lens assembly having a major surface facing a major surface of the waveguide, the adaptive lens assembly comprising:
a waveplate lens; and
a switchable waveplate assembly comprising:
a first non-liquid crystal quarter-wave plate and a second non-liquid crystal quarter-wave plate defining a volume therebetween;
a cell wall extending from the first non-liquid crystal quarter-wave plate to the second non-liquid crystal quarter-wave plate and further defining the volume therebetween; and
a liquid crystal layer disposed in the volume between the first quarter-wave plate and the second quarter-wave plate, wherein liquid crystal molecules of the liquid crystal layer have selectively switchable orientations.
2. An adaptive lens assembly comprising:
a waveplate lens; and
a switchable waveplate assembly comprising:
a first non-liquid crystal quarter-wave plate and a second non-liquid crystal quarter-wave plate defining a volume therebetween;
a cell wall extending from the first non-liquid crystal quarter-wave plate to the second non-liquid crystal quarter-wave plate and further defining the volume therebetween; and
a liquid crystal layer disposed in the volume between the first quarter-wave plate and the second quarter-wave plate, wherein liquid crystal molecules of the liquid crystal layer have selectively switchable orientations.
3. The display device of claim 1 , wherein the switchable waveplate assembly further comprises an electrode pattern disposed in the volume between the first quarter-wave plate and the second quarter-wave plate, the electrode pattern comprising a conductive material configured to selectively establish an electric field to change the orientations of the liquid crystal molecules.
4. The display device of claim 3 , wherein the electrode pattern is disposed on the first quarter-wave plate and another electrode pattern is disposed in the volume on the second quarter-wave plate.
5. The display device of claim 1 , wherein the waveplate lens comprises a liquid crystal polymer layer.
6. The display device of claim 5 , wherein the adaptive lens assembly further comprises an alignment layer disposed between the waveplate lens and the first quarter-wave plate, wherein the alignment layer at least partially determines orientations of liquid crystal molecules in the liquid crystal polymer layer.
7. The display device of claim 5 , wherein the waveplate lens comprises an other liquid crystal polymer layer on the liquid crystal polymer layer.
8. The display device of claim 1 , wherein the cell wall comprises an inkjet printable material.
9. The display device of claim 1 , wherein the waveplate lens and the switchable waveplate assembly constitute an adaptive lens subassembly, wherein the adaptive lens assembly comprises a plurality of adaptive lens subassemblies, each adaptive lens subassembly comprising:
a waveplate lens; and
a switchable waveplate assembly.
10. The display device of claim 1 , further comprising an other adaptive lens assembly on the opposite side of the waveguide assembly from the adaptive lens assembly, wherein the other adaptive lens assembly comprises an associated waveplate lens and an associated switchable waveplate assembly.
11. The display device of claim 2 , wherein the switchable waveplate assembly further comprises an electrode pattern disposed in the volume between the first quarter-wave plate and the second quarter-wave plate, the electrode pattern comprising a conductive material configured to selectively establish an electric field to change the orientations of the liquid crystal molecules.
12. The display device of claim 11 , wherein the electrode pattern is disposed on the first quarter-wave plate and an other electrode pattern is disposed in the volume on the second quarter-wave plate.
13. The display device of claim 2 , wherein the waveplate lens comprises a liquid crystal polymer layer.
14. The display device of claim 13 , wherein the adaptive lens assembly further comprises an alignment layer disposed between the waveplate lens and the first quarter-wave plate, wherein the alignment layer at least partially determines orientations of liquid crystal molecules in the liquid crystal polymer layer.
15. The display device of claim 13 , wherein the waveplate lens comprises an other liquid crystal polymer layer on the liquid crystal polymer layer.
16. The display device of claim 2 , wherein the cell wall comprises an inkjet printable material.
17. The display device of claim 2 , wherein the waveplate lens and the switchable waveplate assembly constitute an adaptive lens subassembly, wherein the adaptive lens assembly comprises a plurality of adaptive lens subassemblies, each adaptive lens subassembly comprising:
a waveplate lens; and
a switchable waveplate assembly.