Image display device and display drive method

• US 20020196207A1
• Filed: 12/14/2001
• Published: 12/26/2002
• Est. Priority Date: 06/20/2001
• Status: Active Grant

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Inventors: Machida, Yoshinori, Shigehiro, Kiyoshi, Sakamaki, Motohiko, Matsunaga, Takeshi, Suwabe, Yasufumi, Yamaguchi, Yoshiro
• Granted Patent: US 6,753,844 B2
• Time in Patent Office: Days
• US Class Current: 345/55
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2310/068 Application of pulses of alternating polarity prior to the drive pulse in electrophoretic displays
• CPC Class Codes: G09G 3/34 by control of light from an independent source

Abstract

An image display device is structured with an image display medium, a voltage applying unit and a control unit. The image display medium has black particles and white particles enclosed in a space between a transparent front substrate and a rear substrate. The front substrate is structured with a lamination having a substrate, an electrode and a surface coat layer. The rear substrate is structured with a lamination having a substrate, an electrode and a surface coat layer. The electrode on the front substrate is connected to the voltage applying unit while the voltage applying unit is connected to the control unit. The control unit controls the voltage applying unit to apply to the electrodes of the substrates an alternating voltage at a frequency of from 20 Hz to 20 kHz.

Claims

1. An image display device comprising:

an image display medium having a pair of substrates, an electrode provided on each respective substrate, and a plurality of kinds of particles which are enclosed in a space between the substrates and which are movable due to an electric field formed between the electrodes and which have different colors and electrifying properties; and

a voltage applying unit for applying to the electrodes an alternating voltage having a frequency to move the plurality of kinds of particles.

2. The image display device according to claim 1, wherein the frequency is from 20 Hz to 20 kHz.

3. The image display device according to claim 1, wherein said image display medium further comprises a gap member for maintaining a predetermined gap between the pair of substrates and dividing the space between the substrates into a plurality of cells, with said voltage applying unit applying the alternating voltage per cell.

4. The image display device according to claim 1, wherein the frequency is from 50 Hz to 10 kHz.

5. The image display device according to claim 1, wherein said voltage applying unit applies the alternating voltage to said electrodes once per a plurality of number of times of changes of image on said image display medium.

6. The image display device according to claim 1, wherein said voltage applying unit applies to said electrodes an alternating voltage lower than a display drive voltage for displaying images on said image displaying medium.

7. The image display device according to claim 1, wherein said voltage applying unit applies to said electrodes an alternating voltage higher than a display drive voltage for displaying images on said image displaying medium.

8. The image display device according to claim 1, wherein said voltage applying unit applies to said electrodes, at a predetermined ratio, an alternating voltage equal to or lower than a display drive voltage for displaying images on said image displaying medium and an alternating voltage higher than the display drive voltage.

9. The image display device according to claim 1, wherein said voltage applying unit applies simultaneously a predetermined direct current voltage and the alternating voltage to the electrodes.

10. The image display device according to claim 1, wherein said voltage applying unit includes a changing unit for changing a duty of the alternating voltage.

11. A display drive method for an image display medium having a pair of substrates, an electrode provided on each substrate respectively, and a plurality of kinds of particles which are enclosed in a space between the substrates and which are movable due to an electric field formed between the electrodes and which have different color and electrifying properties, the display drive method comprising:

applying to said electrodes an alternating voltage having a frequency to move the plurality of kinds of particles.

12. The display driving method according to claim 11, wherein the frequency is from 20 Hz to 20 kHz.

13. The display driving method according to claim 11, wherein the frequency is from 50 Hz to 10 kHz.

14. The display driving method according to claim 11, wherein the alternating voltage is applied to said electrodes once per a plurality of number of times of changes of image on said image display medium.

15. The display driving method according to claim 11, wherein the alternating voltage is lower than a display drive voltage for displaying images on said image displaying medium.

16. The display driving method according to claim 11, wherein the alternating voltage is higher than a display drive voltage for displaying images on said image displaying medium.

17. The display driving method according to claim 11, wherein an alternating voltage equal to or lower than a display drive voltage for displaying images on said image displaying medium and an alternating voltage higher than the display drive voltage are applied at a predetermined ratio to said electrodes.

18. The display driving method according to claim 11, wherein the alternating voltage and a predetermined direct current voltage are applied simultaneously to the electrodes.

19. The display driving method according to claim 11, wherein a duty of the alternating voltage is changed.