Driving electro-optic displays

• US 9,424,797 B1
• Filed: 11/17/2015
• Issued: 08/23/2016
• Est. Priority Date: 11/17/2015
• Status: Active Grant

• Current Assignee: Dock Technologies Inc.
• Original Assignee: Dock Technologies Inc.
• Inventors: Levin, Nicholas S., Sandock, Sarah R.
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): McLoone, Peter D
• Application Number:
  US14/943,534
• Time in Patent Office: 280 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/163 Wearable computers, e.g. on a belt
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/3265 Power saving in display device
• CPC Class Codes: G06F 1/3296 by lowering the supply or operating voltage
• CPC Class Codes: G09G 2310/0243 Details of the generation of driving signals
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/19 using electrochromic devices
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/38 using electrochromic devices
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

The technology described in this document may be embodied in a method for controlling a display element. The method includes setting a first drive voltage configured to drive a first terminal of the display element such that the first drive voltage is set to a higher value than a second drive voltage configured to drive a second terminal of the display element. The first and second drive voltages can be configured to cause the display element to present a first display state. The method also includes performing adjustments to the first drive voltage and the second drive voltage such that the first drive voltage is less than the second drive voltage. The adjustments are configured in accordance with whether the display element is to present a second display state different from the first display state.

Claims

1. A method of controlling multiple display elements, the method comprising:

setting a first drive voltage on a first voltage rail configured to drive a first terminal of each of the multiple display elements;

setting a second drive voltage, less than the first drive voltage, on a second voltage rail configured to drive a second terminal of each of the multiple display elements, wherein the second terminal of each of the multiple display elements is connected to the second voltage rail via a corresponding switch;

providing a first control signal configured to activate each of a first set of one or more of the switches to connect corresponding display elements to the second voltage rail, such that the voltages on the first and second voltage rails cause the corresponding display elements to present a first display state;

performing adjustments to the first drive voltage and the second drive voltage such that the first drive voltage is less than the second drive voltage; and

providing a second control signal configured to activate each of a second set of one or more of the switches to connect corresponding display elements to the second voltage rail, wherein the second set of switches is selected in accordance with whether the corresponding display elements are to present a second display state different from the first display state.

2. The method of claim 1, wherein the second drive voltage is less than the first drive voltage during a first time period, and the adjustments are performed during a second time period following the first time period.

3. The method of claim 2, wherein the first control signal to each of the first set of one or more of the switches is provided during the first time period.

4. The method of claim 2, wherein the second control signal to each of the second set of one or more of the switches is provided during the second time period.

5. The method of claim 4, further comprising adjusting the first drive voltage and the second drive voltage such that the first drive voltage is higher than the second drive voltage during a third time period that follows the second time period.

6. The method of claim 5, further comprising providing, during the third time period, a third control signal to each of one or more of the switches, the third control signal configured to cause the one or more switches to disconnect the corresponding second terminals from the second voltage rail, wherein the third control signal is provided to each of the one or more switches responsive to determining that the corresponding display elements are to present the second display state.

7. The method of claim 1, wherein the first terminal is a common terminal, and the second terminal is a pixel terminal.

8. The method of claim 1, wherein the first display state represents a clear state.

9. The method of claim 1, wherein the second display state represents a colored state.

10. The method of claim 1, wherein the first terminal of each of the multiple display elements is connected to each other, and connected to the first voltage rail via a corresponding switch.

11. A system comprising:

a first driver configured to set a voltage on a first voltage rail connected to a first terminal of each of multiple display elements;

a second driver configured to set a voltage on a second voltage rail connected to a second terminal of each of the multiple display elements, wherein the second terminal of each of the multiple display elements is connected to the second voltage rail via a corresponding switch; and

a controller configured to;

cause the first driver to generate a first drive voltage and cause the second driver to generate a second drive voltage, wherein the first drive voltage is higher than the second drive voltage, and the first and second drive voltages are usable by the display element to present a first display state,

provide a first control signal configured to activate each of a first set of one or more of the switches to connect corresponding display elements to the second voltage rail,

cause adjustments to the first drive voltage and the second drive voltage such that the first drive voltage is less than the second drive voltage,

provide a second control signal configured to activate each of a second set of one or more of the switches to connect corresponding display elements to the second voltage rail, wherein the second set of switches is selected in accordance with whether the corresponding display elements are to present a second display state different from the first display state.

12. The system of claim 11, wherein the second drive voltage is less than the first drive voltage during a first time period, and the adjustments are performed during a second time period following the first time period.

13. The system of claim 12, wherein the first control signal to each of the first set of one or more of the switches is provided during the first time period.

14. The system of claim 12, wherein the second control signal to each of the second set of one or more of the switches is provided during the second time period.

15. The system of claim 14, wherein the controller is configured to adjust the first drive voltage and the second drive voltage such that the first drive voltage is higher than the second drive voltage during a third time period that follows the second time period.

16. The system of claim 15, wherein the controller is configured to provide, during the third time period, a third control signal to each of one or more of the switches, the third control signal configured to cause the one or more switches to disconnect the corresponding second terminals from the second voltage rail, wherein the third control signal is provided to each of the one or more switches responsive to determining that the corresponding display elements are to present the second display state.

17. The system of claim 11, wherein the first terminal is a common terminal, and the second terminal is a pixel terminal.

18. The system of claim 11, wherein the first display state represents a clear state.

19. The system of claim 11, wherein the second display state represents a colored state.

20. The system of claim 11, wherein the first terminal of each of the multiple display elements is connected to each other, and connected to the first voltage rail via a corresponding switch.

21. One or more non-transitory machine-readable storage devices having encoded thereon computer readable instructions for causing one or more processors to perform operations comprising:

setting a first drive voltage on a first voltage rail configured to drive a first terminal of each of multiple display elements;

setting a second drive voltage, less than the first drive voltage, on a second voltage rail configured to drive a second terminal of each of the multiple display elements, wherein the second terminal of each of the multiple display elements is connected to the second voltage rail via a corresponding switch;

providing a first control signal configured to activate each of a first set of one or more of the switches to connect corresponding display elements to the second voltage rail, such that the voltages on the first and second voltage rails cause the corresponding display elements to present a first display state;

performing adjustments to the first drive voltage and the second drive voltage such that the first drive voltage is less than the second drive voltage; and

providing a second control signal configured to activate each of a second set of one or more of the switches to connect corresponding display elements to the second voltage rail, wherein the second set of switches is selected in accordance with whether the corresponding display elements are to present a second display state different from the first display state.

22. The one or more machine-readable storage devices of claim 21, wherein the second drive voltage is less than the first drive voltage during a first time period, and the adjustments are performed during a second time period following the first time period.

23. The one or more machine-readable storage devices of claim 22, wherein the first control signal to each of the first set of one or more of the switches is provided during the first time period.

24. The one or more machine-readable storage devices of claim 22, wherein the second control signal to each of the second set of one or more of the switches is provided during the second time period.

25. The one or more machine-readable storage devices of claim 24, further comprising instructions for adjusting the first drive voltage and the second drive voltage such that the first drive voltage is higher than the second drive voltage during a third time period that follows the second time period.

26. The one or more machine-readable storage devices of claim 25, further comprising instructions for providing, during the third time period, a third control signal to each of one or more of the switches, the third control signal configured to cause the one or more switches to disconnect the corresponding second terminals from the second voltage rail, wherein the third control signal is provided to each of the one or more switches responsive to determining that the corresponding display elements are to present the second display state.

27. The one or more machine-readable storage devices of claim 21, wherein the first terminal is a common terminal, and the second terminal is a pixel terminal.

28. The one or more machine-readable storage devices of claim 21, wherein the first display state represents a clear state.

29. The one or more machine-readable storage devices of claim 21, wherein the second display state represents a colored state.

30. The one or more machine-readable storage devices of claim 21, wherein the first terminal of each of the multiple display elements is connected to each other, and connected to the first voltage rail via a corresponding switch.