ELECTROPHORETIC DISPLAY DEVICE AND METHOD OF DRIVING SAME

• US 20090046052A1
• Filed: 08/06/2008
• Published: 02/19/2009
• Est. Priority Date: 08/14/2007
• Status: Active Grant

• Current Assignee: Hydis Technology Company Limited (E Ink Holdings Incorporated)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: KIM, Joo-Young, PARK, Cheol-Woo
• Granted Patent: US 8,624,831 B2
• Time in Patent Office: Days
• US Class Current: 345/107
• 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 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2320/0204 Compensation of DC component across the pixels in flat panels
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• 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

An electrophoretic display (“EPD”) device includes an EPD panel to display an image, and a driving circuit to drive the EPD panel. To display an individual image, the driving circuit supplies a first refresh signal to display a black gray scale, a second refresh signal to display a white gray scale, an inverse image data signal to display an inversed image of the individual image, an image data signal to display the individual image, and a reset signal to provide a direct current unbalance between the first and second refresh signals to the EPD panel.

Claims

1. An electrophoretic display device, comprising:

an electrophoretic display panel to display images; and

a driving circuit to drive the electrophoretic display panel,

wherein to display an individual image in a first signal supplying period, the driving circuit supplies a first refresh signal to display a black gray scale, a second refresh signal to display a white gray scale, an inverse image data signal to display an inversed image of the individual image, an image data signal to display the individual image, and a reset signal to provide a direct current unbalance between the first refresh signal and the second refresh signal to the electrophoretic display panel.

2. The electrophoretic display device of claim 1, wherein the reset signal displays the black gray scale.

3. The electrophoretic display device of claim 1, wherein the driving circuit further supplies a reset compensation signal to the electrophoretic display panel in a second signal supplying period to compensate for the reset signal supplied in the first signal supplying period.

4. The electrophoretic display device of claim 1, wherein the first refresh signal and the second refresh signal are supplied for the same length of time.

5. The electrophoretic display device of claim 1, wherein the reset signal is supplied for the same duration in each signal supplying period.

6. The electrophoretic display device of claim 5, wherein the reset signal is supplied for a time corresponding to about 6% to about 7% of a supplying time of the first refresh signal.

7. The electrophoretic display device of claim 3, wherein the reset compensation signal displays a white gray scale.

8. The electrophoretic display device of claim 3, wherein a supplying time of the reset compensation signal is identical to a supplying time of the reset signal.

9. The electrophoretic display device of claim 1, wherein the electrophoretic display panel comprises a thin film transistor substrate on which gate lines and data lines are arranged and an electrophoretic element to display an image by reflecting light at an upper surface of the thin film transistor substrate.

10. The electrophoretic display device of claim 9, wherein the electrophoretic element comprises a microcapsule having particles that are negatively charged and positively charged and display a white gray scale and a black gray scale.

11. The electrophoretic display device of claim 10, wherein the driving circuit comprises a gate driver to drive the gate lines, a data driver to drive the data lines, a timing controller to supply a data signal and a control signal to the data driver, and a driving voltage supply to supply a driving voltage.

13. The electrophoretic display device of claim 1, wherein the supplying time of the second refresh signal is about 6% to about 7% less than the supplying time of the first refresh signal in the first signal supplying period.

12. An electrophoretic display device, comprising:

an electrophoretic display panel to display images; and

a driving circuit to supply, to the electrophoretic display panel for signal supplying periods during which signals to display an individual image are applied, a first refresh signal and a second refresh signal that have opposite polarities, an inverse image data signal to display an inversed image of the individual image, and an image data signal to display the individual image to the electrophoretic display panel,

wherein a supplying time of the second refresh signal is shorter than a supplying time of the first refresh signal at a first signal supplying period, and the supplying time of the second refresh signal is identical to the supplying time of the first refresh signal in a second signal supplying period following the first signal supplying period.

14. A method of driving an electrophoretic display device, comprising:

supplying a first refresh signal;

supplying a reset signal to provide a direct current unbalance;

supplying a second refresh signal to compensate for the first refresh signal;

supplying an inverse image data signal to display an inversed image of an individual image; and

supplying an image data signal to display the individual image,

wherein the first refresh signal, the reset signal, the second refresh signal, the inverse image data signal, and the image data signal are supplied to the electrophoretic display panel for a signal supplying period to display the individual image on the electrophoretic display panel.

15. The method of claim 14, wherein the first refresh signal and the reset signal display a black gray scale, and the second refresh signal displays a white gray scale.

16. The method of claim 14, further comprising supplying a reset compensation signal to the electrophoretic display panel to compensate for the reset signal supplied for a previous signal supplying period.

17. The method of claim 16, wherein the reset compensation signal displays the white gray scale.

18. The method of claim 16, wherein a supplying time of the reset compensation signal is identical to a supplying time of the reset signal.

19. The method of claim 14, wherein the reset signal is supplied to the electrophoretic display panel for the same length of time in each signal supplying period.

20. The method of claim 19, wherein the reset signal is supplied to the electrophoretic display panel for a time corresponding to about 6% to about 7% of a supplying time of the first refresh signal.