Electrophoretic display and driving method thereof

• US 20080143700A1
• Filed: 05/30/2007
• Published: 06/19/2008
• Est. Priority Date: 12/13/2006
• Status: Active Grant

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Yang, Hui Eun, Shin, Sung Woo
• Granted Patent: US 8,179,387 B2
• Time in Patent Office: Days
• US Class Current: 345/208
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2310/068 Application of pulses of alternating polarity prior to the drive pulse in electrophoretic displays
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167

Abstract

A method of driving at least one cell of an electrophoretic display panel through a pixel electrode and a common electrode includes storing at least first data representative of an image currently displayed and second data representative of an image to be displayed; and applying a first AC data waveform and a first AC common waveform for initializing the at least one cell during a first number of frames, applying a second AC data waveform and a second AC common waveform for displaying the second data during a second number of frames, wherein the first number of frames depends on the first data and the second number of frames depends on the second data.

Claims

1. A display device, comprising:

an electrophoretic display panel including at least one cell displaying a first data; and

a controller for changing a state of the at least one cell to display a second data, the controller responsive to the first and second data to apply an AC common waveform and an AC data waveform to the at least one cell during an initialization time and a entry time,

wherein an initializing voltage of the AC common waveform and an initializing voltage of the AC data waveform are generated according to the first data during the initialization time,

and an entry voltage of the AC common waveform and an entry voltage of the AC data waveform are generated according to the second data during the entry time.

2. The display device of claim 1, wherein the AC data waveform supplies a reset voltage suitable for initializing the at least one cell during a data initializing number of frames in the initialization time.

3. The display device of claim 2, wherein the data initializing number of frames increases when the first data decreases.

4. The display device of claim 1, wherein the AC data waveform supplies a first stabilizing voltage suitable for stabilizing the at least one cell during a first stabilizing number of frames in a first stabilizing time following the initializing time.

5. The display device of claim 4, wherein the AC data waveform supplies a second stabilizing voltage suitable for stabilizing the at least one cell during a second stabilizing number of frames in a second stabilizing time following the first stabilizing time.

6. The display device of claim 5, wherein the first and second stabilizing numbers of frames are the same.

7. The display device of claim 1, wherein the AC data waveform supplies an entry voltage suitable for displaying the second data at the at least one cell during the data entry number of frames in the entry time.

8. The display device of claim 7, wherein the AC data waveform has a first value and the data entry number of frames increases with the second data.

9. The display device of claim 7, wherein the AC data waveform has a second value and the data entry number of frames decreases with the second data.

10. The display device of claim 1, further comprising a storage part for storing first and second bits in accordance with the first data and the second data, the first bit indicative of the AC data waveform to be applied to the pixel electrode and the second bit indicative of the AC common waveform to be applied to the common electrode.

11. A method of driving at least one cell of an electrophoretic display panel through a pixel electrode and a common electrode, the method comprising:

storing at least first data representative of an image currently displayed and second data representative of an image to be displayed; and

applying a first AC data waveform and a first AC common waveform for initializing the at least one cell during a first number of frames, applying a second AC data waveform and a second AC common waveform for displaying the second data during a second number of frames, wherein the first number of frames depends on the first data and the second number of frames depends on the second data.

12. The method of claim 11, further comprising applying a third AC data waveform and third AC common waveform for stabilizing the at least one cell during a third number of frames following the first number of frames.

13. The method of claim 12, further comprising applying a fourth AC data waveform and fourth AC common waveform for stabilizing the at least one cell during a fourth number of frames following the third number of frames.

14. The method of claim 13, wherein the third and fourth number of frames are the same.

15. The method of claim 11, wherein the first number of frames increases when the first data decreases.

16. The method of claim 11, wherein the second AC data waveform has a first value and the second number of frames increases with the second data.

17. The method of claim 16, wherein the second AC data waveform has a second value and the second number of frames decreases with the second data.

18. The method of claim 11, further comprising storing first and second bits in accordance with the first data and the second data, the first bit indicative of the AC data waveform to be applied to the pixel electrode and the second bit indicative of the AC common waveform to be applied to the common electrode.