Method for producing a bistable display device with low-voltage microcontroller

1. A method for producing a segmented electrophoretic display device comprising a bistable display operating at predetermined opposing voltages and an electronic circuit with a single low voltage microcontroller for controlling the display according to a control programme, comprising the following steps:

connecting input/output ports of said single low voltage microcontroller to conductive areas of the bistable display, wherein the single low voltage microcontroller is (i) different from a specific display controller for a bistable display, and (ii) configured to deliver voltages on the input/output ports that are lower in absolute value than the predetermined voltages, and

connecting a source of compensation voltage, that includes at least one hybrid charge pump and is separate from the single low voltage microcontroller, directly to at least one of said conductive areas of the bistable display, to combine with a voltage delivered by the single low voltage microcontroller and reach said predetermined opposing voltages.

2. A method according to claim 1 , wherein said source of compensation voltage is a voltage generator.

3. A method according to claim 2 , wherein said control programme controls said voltage generator to provide said compensation voltage.

4. A method according to claim 3 , wherein said voltage generator is configured to provide voltage values equal to (+5; −2) volts on a single output.

5. A method according to claim 4 , wherein said single low voltage microcontroller is configured to provide a pair of voltages equal to or within 10 percent of (+3; 0) volts on input/output ports.

6. A method according to claim 3 , wherein said control programme controls said voltage generator to provide voltage values equal to (−5V, +5V) to control a color switching of the segments or the background of the display and voltage values equal to (−2V, +2V) to maintain the colors of the segments or the background.

7. A method according to claim 1 , wherein said single low voltage microcontroller comprises GPIO input/output ports that can be individually controlled with a “0”, “1” status and high impedance.

8. A method according to claim 1 , wherein said control programme provides for a string of the following successive sequences:

homogenization in a uniform color of all the segments including a black or white background with a duration of 5 time units;

inversion of the uniform color of all the segments including the white background if previously black or black if previously white with a duration of 7 time units;

if needed, updating the segments in white if previously black or black if previously white with a duration of 5 time units.

9. A segmented electrophoretic display device comprising a bistable display operating at predetermined opposing voltages and an electronic circuit with a single low voltage microcontroller for controlling the display according to a control programme, comprising:

said single low voltage microcontroller has input/output ports connected to the conductive areas of the bistable display, wherein the single low voltage microcontroller is (i) different from a specific display controller for a bistable display, and (ii) configured to deliver voltages on the input/output ports that are lower in absolute value than the predetermined voltages, and

a compensation voltage generator, that includes at least one hybrid charge pump and is separate from the single low voltage microcontroller, configured to deliver a compensation voltage directly to at least one of said conductive areas of the bistable display, to combine with a voltage delivered by the single low voltage microcontroller and reach said predetermined opposing voltages.

10. A device according to claim 9 , characterized wherein the compensation voltage generator comprises a hybrid charge pump combining a voltage doubling circuit and a voltage inverter circuit, the respective output voltages of the doubling circuit and the inverter circuit being alternately combined on a single output of the charge pump.

11. A device according to claim 9 , wherein the single low voltage microcontroller comprises a control programme for supplying the voltages at times and for durations according to a balanced control scheme so that the average value of the voltage seen from each of the segments is within 10% of 0 volt.

12. The method according to claim 1 , wherein said at least one conductive area is associated with the background of the bistable display.

13. A device according to claim 9 , wherein said at least one conductive area is associated with the background of the bistable display.

14. The method according to claim 1 , wherein the microcontroller is powered by a supply voltage that is lower in absolute value than the predetermined voltages.

15. The device according to claim 9 , wherein the microcontroller is powered by a supply voltage that is lower in absolute value than the predetermined voltages.

16. A segmented electrophoretic display device comprising a bistable display operating at predetermined opposing voltages and an electronic circuit with a single low voltage microcontroller for controlling the display according to a control programme, comprising:

said single low voltage microcontroller which is (i) different from a specific display controller for a bistable display, and (ii) configured to deliver voltages on input/output ports, lower in absolute value than the predetermined voltages, and

a compensation voltage generator configured to compensate said voltages delivered by the single low voltage microcontroller and reach at least said predetermined opposing voltages,

wherein the compensation voltage generator comprises a hybrid charge pump combining a voltage doubling circuit and a voltage inverter circuit, the respective output voltages of the doubling circuit and the inverter circuit being alternately combined on a single output of the charge pump.

17. A method for producing a segmented electrophoretic display device comprising a bistable display operating at predetermined opposing voltages and an electronic circuit with a single low voltage microcontroller for controlling the display according to a control programme, comprising the following steps:

connecting input/output ports of said single low voltage microcontroller to conductive areas of the bistable display, wherein the single low voltage microcontroller is (i) different from a specific display controller for a bistable display, and (ii) configured to deliver voltages on the input/output ports that are lower in absolute value than the predetermined voltages, and

connecting a source of compensation voltage, separate from the single low voltage microcontroller, to at least one of said conductive areas of the bistable display, to combine with a voltage delivered by the single low voltage microcontroller and reach said predetermined opposing voltages, wherein the source of the compensation voltage comprises a hybrid charge pump combining a voltage doubling circuit and a voltage inverter circuit, the respective output voltages of the doubling circuit and the inverter circuit being alternately combined on a single output of the charge pump.

18. A segmented electrophoretic display device comprising a bistable display operating at predetermined opposing voltages and an electronic circuit with a single low voltage microcontroller for controlling the display according to a control programme, comprising:

said single low voltage microcontroller has input/output ports connected to the conductive areas of the bistable display, wherein the single low voltage microcontroller is (i) different from a specific display controller for a bistable display, and (ii) configured to deliver voltages on the input/output ports that are lower in absolute value than the predetermined voltages, and

a compensation voltage generator separate from the single low voltage microcontroller, configured to deliver a compensation voltage to at least one of said conductive areas of the bistable display, to combine with a voltage delivered by the single low voltage microcontroller and reach said predetermined opposing voltages, wherein the compensation voltage generator comprises a hybrid charge pump combining a voltage doubling circuit and a voltage inverter circuit, the respective output voltages of the doubling circuit and the inverter circuit being alternately combined on a single output of the charge pump.