Strain sensing in foldable displays

1. A controller for an electronic display panel, comprising;

processing circuitry; and

a memory storing instructions that, when executed the processing circuitry, causes the controller to:

receive sensor signals from one or more piezoresistive sensors disposed in the electronic display panel;

determine an amount of strain in the electronic display panel based on the received sensor signals;

determine a bend angle of the electronic display panel based on the determined amount of strain; and

update a value in a strain buffer based on the determined amount of strain, the strain buffer storing one or more values indicating a history of strain in the electronic display panel.

2. The controller of claim , wherein execution of the instructions further causes the controller to:

determine that the bend angle of the electronic display panel is greater than a threshold bend angle; and

deactivate the electronic display panel based on determining that the bend angle is greater than the threshold bend angle.

3. The controller of claim 1 , wherein execution of the instructions further causes the controller to:

determine that the bend angle of the electronic display panel is less than a threshold bend angle; and

activate the electronic display panel based on determining that the bend angle does not exceed the threshold bend angle.

4. The controller of claim 1 , wherein execution of the instructions further causes the controller to:

determine that the bend angle of the electronic display panel is greater than a threshold bend angle and

operate the electronic display panel a low power mode based on determining that the bend angle is greater than the threshold bend angle.

5. The controller of claim 1 , wherein execution of the instructions further causes the controller to:

determine that the bend angle of the electronic display panel is less than a threshold bend angle; and

operate the electronic display panel in a standard power mode based on determining that the bend angle is less than the threshold bend angle.

6. The controller of claim 1 , wherein execution of the instructions for updating the value in the strain buffet causes the controller to:

detect a change in state of the electronic display panel, between a folded state and an unfolded state, based on the determined bend angle; and

increment the value responsive to detecting the change in state of the electronic display panel.

7. The controller of claim 1 , wherein execution of the instructions for updating the configuration of the electronic display panel causes the controller to:

output an indication signaling a degradation of the electronic display panel based on the history of strain.

8. A method of sensing strain in an electronic display panel, comprising:

receiving sensor signals from one or more piezoresistive sensors disposed in the electronic display panel;

determining an amount of strain on the electronic display panel based on the received sensor signals;

determining a bend angle of the electronic display panel based on the determined amount of strain; and

updating a value in a strain buffer based on the determined amount of strain, the strain buffer storing one or more values indicating a history of strain in the electronic display panel.

9. The method of claim 8 , further comprising:

determining that the bend angle of the electronic display panel is greater than a threshold bend angle; and

deactivating the electronic display panel based on determining that the bend angle is greater than the threshold bend angle.

10. The method of claim 8 , further comprising:

determining that the bend angle of the electronic display panel is less than a threshold bend angle; and

activating the electronic display panel based on determining that the bend angle does not exceed the threshold bend angle.

11. The method of claim 8 , further comprising:

determining that the bend angle of the electronic display panel is greater than a threshold bend angle;

operating the electronic display panel in a low power mode based on determining that the bend angle is greater than the threshold bend angle.

12. The method of claim 8 , further comprising:

determining that the bend angle of the electronic display panel is less than a threshold bend angle; and

operating the electronic display panel in a standard power mode based on determining that the bend angle is less than the threshold bend angle.

13. The method of claim 8 , wherein the updating of the value in the stain buffer comprises:

detecting a change in state of the electronic display panel, between a folded state and an unfolded state, based on the determined bend angle; and

incrementing the value responsive to detecting the change in state of the electronic display panel.

14. The method of claim 8 , wherein the updating of the configuration comprises:

outputting an indication signaling a degradation of the electronic display panel based on the history of strain.

15. A display device, comprising:

an electronic display panel including, a polycrystalline silicon (poly-Si) backplane disposed on a flexible substrate;

one or more piezoresistive sensors disposed in the electronic display panel, each of the one or more piezoresistive sensors including one or more strain gauges formed on the poly-Si backplane; and

a display controller coupled to the one or more piezoresistive sensors and configured to:

receive sensor signals from the one or more piezoresistive sensors;

determine an amount of strain in the electronic display panel based on the received sensor signals;

determine a bend angle of the electronic display panel based on the determined amount of strain; and

update a configuration of the electronic display panel based at least in part on the determined bend angle.

16. The display device of claim 15 , wherein the one or more strain gauges are formed by doping the poly-Si backplane.

17. The display device of claim 15 , wherein the one or more piezoresistive sensors are disposed outside an active area of the electronic display panel.