Rollable display device with strain reduction

1. A rollable display device comprising:

an inner housing, the inner housing having an inner slot;

a rollable display, the rollable display having a bend portion, the bend portion being disposed through the inner slot; and

a strain reducer, the strain reducer operably connected to the rollable display to reduce strain at the bend portion.

2. The device of claim 1 wherein the rollable display comprises a first layer, a second layer disposed on the first layer, and a third layer disposed on the second layer, and the strain reducer comprises a first channel formed in the third layer of the bend portion.

3. The device of claim 1 wherein the strain reducer further comprises a second channel formed in the first layer of the bend portion.

4. The device of claim 1 wherein the rollable display comprises a first layer, a second layer disposed on the first layer, and a third layer disposed on the second layer, and the strain reducer comprises an alternative material portion disposed in the third layer of the bend portion, an alternative material of the alternative material portion being selected for thickness and modulus of elasticity so that the neutral line, which is free of stress when the rollable display is bent, is at or near the third layer of the bend portion.

5. The device of claim 1 wherein the rollable display comprises a first layer, a second layer disposed on the first layer, and a third layer disposed on the second layer, and the strain reducer comprises a fourth layer disposed on the third layer of the bend portion, the material of the fourth layer being selected for thickness and modulus of elasticity so that the neutral line, which is free of stress when the rollable display is bent, is at or near the fourth layer of the bend portion.

6. The device of claim 1 further comprising an outer housing rotatable about the inner housing;

wherein the strain reducer comprises a spiral groove formed in one of the inner housing and the outer housing; and

a bolt operably connected to the other of the inner housing and the outer housing, the bolt being disposed in the spiral groove.

7. A rollable display device comprising:

an inner housing, the inner housing having an inner slot;

an outer housing, the outer housing being rotatable about the inner housing;

a rollable display, the rollable display having a bend portion, the bend portion being disposed through the inner slot; and

means for reducing strain of the bend portion.

8. The device of claim 7 wherein the means for reducing strain comprises means for increasing radius of the bend portion.

9. The device of claim 7 wherein the means for reducing strain comprises means for locating a neutral line of the rollable display at a selected layer of the bend portion.

10. The device of claim 7 wherein the means for reducing strain comprises means for reducing cycling of the bend portion.

11. The device of claim 7 further comprising means for switching, the means for switching being responsive to position of the rollable display.

12. The device of claim 1 further comprising an outer housing rotatable about the inner housing, the outer housing having an outer slot, the rollable display being disposed through the outer slot;

wherein the strain reducer comprises a first cavity formed in the outer housing at a first distance from the outer slot, a bolt located at a second distance from the inner slot and urged toward the outer housing;

wherein the bolt is received in the first cavity when the bolt is aligned with the first cavity, and the difference between the first distance and the second distance provides a desired length of the rollable display between the inner slot and the outer slot when the bolt is aligned with the first cavity.

13. The device of claim 12 further comprising a switch responsive to position of the bolt.

14. The device of claim 13 wherein the switch is used to switch a device function selected from the group consisting of drive motor power, electronics power, electronics operating mode, rollable display image power, and rollable display connection.

15. The device of claim 12 wherein the rollable display urges the bolt toward the inner housing when the bolt is not aligned with the first cavity.

16. The device of claim 12 further comprising a second cavity formed in the outer housing at a third distance from the outer slot, and a transition cavity formed in the outer housing between the first cavity and the second cavity.

17. The device of claim 16 wherein the second distance and the third distance are equal.

18. The device of claim 16 wherein the inner housing further comprises electronics, and the rollable display further comprises a connection portion connectable to the electronics, wherein the connection portion is detachable from the electronics when the inner slot is aligned with the outer slot.

19. The device of claim 16 further comprising a switch responsive to movement of the bolt, the switch having a first state when the bolt is received in the first cavity and a second state when the bolt is received in the second cavity.

20. The device of claim 12 wherein the bolt is moveable to a third distance from the inner slot, the inner slot being aligned with the outer slot when the bolt is at the third distance.

21. The device of claim 20 further comprising a foot operably connected to the bolt, a display connection adapted to receive a connection portion of the rollable display and having a latch, wherein the foot is operable to engage the latch and release the connection portion from the display connection when the inner slot is aligned with the outer slot.

22. A rollable display device comprising:

an inner housing, the inner housing having an inner slot and an opening;

an outer housing, the outer housing being rotatable about the inner housing, the outer housing having an outer slot and a cavity;

a rollable display, the rollable display being disposed through the inner slot and the outer slot;

a bolt, the bolt being slidably disposed in the opening; and

a spring, the spring urging the bolt toward the outer housing;

wherein the bolt is received in the cavity when a desired length of the rollable display is positioned between the inner slot and the outer slot.

23. The device of claim 22 further comprising a switch, the switch being responsive to position of the bolt.