Method of driving electrophoresis display device, electrophoresis device, and electronic apparatus

1. A method of driving an electrophoresis display device having a displaying portion which includes an electrophoresis element containing electrophoresis particles and disposed between a first electrode and a second electrode opposing to one another and which consists of a plurality of pixels, comprising:

after performing an image writing step in which an image is written into the displaying portion by applying a first potential or a second potential to the first electrode separately provided for the pixel and applying a reference pulse in which the first potential and the second potential repeatedly alternate at a predetermined interval to the second electrode which is a common electrode shared by all the pixels,

performing at least one contrast maintaining step including a short term interval step in which the second electrode and all the first electrodes fall in a high impedance state for five or less seconds and an auxiliary pulse inputting step in which at least one cycle of the reference pulse is applied to the second electrode and a potential which is equivalent to the potential applied during the image writing step is applied to the first electrode while the reference pulse is applied.

2. The method of driving an electrophoresis device according to claim 1 , wherein the contrast maintaining step is performed a plurality of times.

3. The method of driving an electrophoresis device according to claim 2 , wherein a period of the short interval step is changed for every contrast maintaining step.

4. The method of driving an electrophoresis device according to claim 1 , wherein the contrast maintaining step is continued until a next image writing step begins.

5. The method of driving an electrophoresis device according to claim 1 , wherein the first electrode is applied with a potential which is equivalent to the potential applied during the image writing step and the second electrode comes to fall in a high impedance state in the short term interval step.

6. The method of driving an electrophoresis device according to claim 1 , wherein after the contrast maintaining step, a control portion performs a refresh step including:

a long term interval step in which the first electrodes and the second electrode fall in a high impedance state for 5 to 60 minutes, and

a refresh pulse input step in which a pulse which generates a potential difference between the first electrode and the second electrode, the potential difference being equivalent to that caused in the image writing operation, is applied to the first electrode.

7. An electrophoresis device having a displaying portion which includes an electrophoresis element containing electrophoresis particles and disposed between a first electrode and a second electrode opposing to one another and which consists of a plurality of pixels, wherein a control portion performs at least one contrast maintaining operation including:

a short term interval operation in which the second electrode and all the first electrodes fall in a high impedance state for five or less seconds; and

an auxiliary pulse inputting operation in which at least one cycle of a reference pulse is applied to the second electrode and a potential which is equivalent to the potential applied during the image writing step is applied to the first electrode while the reference pulse is applied, after performing an image writing operation in which an image is written into the displaying portion by applying a first potential or a second potential to the first electrode separately provided for the pixel and applying the reference pulse in which the first potential and the second potential repeatedly alternate at a predetermined interval to the second electrode which is a common electrode shared by all the pixels.

8. The electrophoresis device according to claim 7 , wherein the control portion performs a contrast maintaining operations a plurality of times.

9. The electrophoresis device according to claim 8 , wherein a period of the short term interval operations is changed for every contrast maintaining operation.

10. The electrophoresis device according to claim 7 , wherein the control portion makes the contrast maintaining operation continue until a next image writing operation begins.

11. The electrophoresis device according to claim 7 , wherein the short term interval operation is an operation for applying a potential which is equivalent to the potential applied during the image writing operation to the first electrode and making the second electrode be in a high impedance state.

12. The electrophoresis device according to claim 7 , wherein, after the contrast maintaining operation, the control portion performs a refresh operation including:

a long term interval operation in which the first electrodes and the second electrode fall in a high impedance state for 5 to 60 minutes, and

a refresh pulse inputting operation in which a pulse which causes a potential difference between the first electrode and the second electrode, the difference being equivalent to that caused in the image writing operation is applied to the first electrode.

13. The electrophoresis device according to claim 7 , wherein the pixel and the control portion are connected to one another via a pixel circuit disposed to correspond to the pixel, respectively and the pixel circuit includes a memory portion.

14. An electronic apparatus comprising the electrophoresis device according to claim 7 .