Electrophoretic device with capacitive storage and applied fluctuating signal, method of driving the same, and electronic apparatus

• US 8,350,802 B2
• Filed: 01/24/2008
• Issued: 01/08/2013
• Est. Priority Date: 01/25/2007
• Status: Active Grant

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Hirayama, Hiroshi, Yoshida, Junpei
• Primary Examiner(s): Nguyen, Chanh
• Assistant Examiner(s): Park, Sanghyuk
• Application Number:
  US12/019,342
• Publication Number:
  US 20080277279A1
• Time in Patent Office: 1,811 Days
• Field of Search: 345/107
• US Class Current: 345/107
• CPC Class Codes: G01N 27/44713 Particularly adapted electric power supply

Abstract

Disclosed is a method of driving an electrophoretic device that includes an electrophoretic element having a first electrode, a second electrode, and an electrophoretic layer disposed between the first and second electrodes, and further includes a capacitor connected to the first electrode at one terminal. The method includes (a) applying a reference potential or a first potential higher than the reference potential to the first electrode of the electrophoretic element and the terminal of the capacitor and applying the reference potential to the second electrode of the electrophoretic element, and (b) applying a signal fluctuating between a second potential and a third potential to the second electrode subsequently to the step (a), the second potential being equal to or higher than the reference potential, the third potential being higher than the second potential and being equal to or lower than the first potential.

Claims

1. A method of driving an electrophoretic device having a plurality of scan lines, a data line crossing the plurality of scan lines, a plurality of pixels each corresponding to an intersection between one of the plurality of scan lines and the data line, each of the plurality of pixels including a first electrode, a second electrode, and an electrophoretic layer disposed between the first and second electrodes, each pixel further including a capacitor connected to the first electrode at one terminal, the plurality of pixels including a first pixel and a second pixel, the method comprising:

sequentially selecting the plurality of scan lines, applying a reference potential via the data line to the first electrode and the terminal of the capacitor in the first pixel which is connected to the selected scan line, applying the reference potential to the second electrode of the first pixel, applying a first potential higher than the reference potential via the data line to the first electrode and the terminal of the capacitor in the second pixel which is connected to the selected scan line, and applying the reference potential to the second electrode of the second pixel; and

during a first period of time, applying a signal to the second electrode after completion of the sequentially selecting,

wherein the signal alternates between a second potential and a third potential a plurality of times during the first period of time, the second potential being higher than the reference potential, the third potential being higher than the second potential and being lower than the first potential,

wherein during the first period of time, the electric potential of the first electrode of the second pixel decreases from the first potential but remains above a fourth potential,

wherein the third potential is lower than the fourth potential, and

wherein an electric potential of the second electrode does not change during selecting the plurality of scan lines.

2. The method according to claim 1, wherein the sequentially selecting and the applying the signal are repeated more than one time.

3. The method according to claim 1, wherein during sequentially selecting the plurality of scan lines, the reference potential is applied to the first electrode and the terminal of the capacitor in a first pixel, and the first potential is applied to the first electrode and the terminal of the capacitor in a second pixel.

4. The method according to claim 1,

wherein during the first period of time, the electric potential of the first electrode of the first pixel increases from the reference potential to a fifth potential, and

wherein the second potential is higher than the fifth potential.

5. An electrophoretic device comprising:

a plurality of scan lines;

a data line crossing the plurality of scan lines;

a plurality of pixels each corresponding to an intersection between one of the plurality of scan lines and the data line, the plurality of pixels including a first pixel and a second pixel; and

a drive circuit connected to the pixels, wherein

each pixel includes a first electrode, a second electrode, an electrophoretic layer disposed between the first and second electrodes, and a capacitor connected to the first electrode at one terminal, and

the drive circuit performs;

sequentially selecting the plurality of scan lines, applying a reference potential via the data line to the first electrode and the terminal of the capacitor in the first pixel which is connected to the selected scan line, and applying the reference potential to the second electrode of the first pixel, applying a first potential higher than the reference potential via the data line to the first electrode and the terminal of the capacitor in the second pixel which is connected to the selected scan line, and applying the reference potential to the second electrode of the second pixel; and

during a first period of time, applying a signal to the second electrode after completion of the sequentially selecting,

wherein the signal alternates between a second potential and a third potential a plurality of times during the first period of time, the second potential being higher than the reference potential, the third potential being higher than the second potential and being lower than the first potential,

wherein during the first period of time, the electric potential of the first electrode of the second pixel decreases from the first potential but remains above a fourth potential,

wherein the third potential is lower than the fourth potential, and

wherein an electric potential of the second electrode does not change during selecting the plurality of scan lines.

6. The electrophoretic device according to claim 5, wherein the second electrode is a common electrode shared by the pixels.

7. The electrophoretic device according to claim 5, wherein the drive circuit repeats the sequentially selecting and the applying the signal more than one time.

8. An electronic apparatus comprising the electrophoretic device according to claim 5 as a display unit.

9. The electrophoretic device according to claim 5, wherein during sequentially selecting the plurality of scan lines, the reference potential is applied to the first electrode and the terminal of the capacitor in a first pixel, and the first potential is applied to the first electrode and the terminal of the capacitor in a second pixel.

10. The electrophoretic device according to claim 5,

wherein during the first period of time, the electric potential of the first electrode of the first pixel increases from the reference potential to a fifth potential, and

wherein the second potential is higher than the fifth potential.