METHODS FOR DRIVING ELECTROPHORETIC DISPLAYS USING DIELECTROPHORETIC FORCES
First Claim
Patent Images
1. A method for operating a dielectrophoretic display, the method comprising:
- providing a dielectrophoretic medium comprising a fluid and a plurality of at least one type of particle within the fluid;
providing two electrodes, one disposed on each side of the dielectrophoretic medium;
applying to the medium by means of the two electrodes_an electric field having a first frequency, thereby causing the particles to undergo electrophoretic motion and producing a first optical state; and
applying to the medium by means of the two electrodes an electric field having a second frequency higher than the first frequency, thereby causing the particles to undergo dielectrophoretic motion and producing a second optical state different from the first optical state,wherein the application of the second frequency electric field is effected by;
applying the second frequency electric field for a first period;
thereafter applying zero electric field for a period; and
thereafter applying the second frequency electric field for a second period,and wherein, during said first and second periods and the intervening period of zero electric field, the electric field of the first frequency is not applied.
1 Assignment
0 Petitions
Accused Products
Abstract
A dielectrophoretic display has a substrate having walls defining a cavity, the cavity having a viewing surface and a side wall inclined to the viewing surface. A fluid is contained within the cavity; and a plurality of particles are present in the fluid. There is applied to the substrate an electric field effective to cause dielectrophoretic movement of the particles so that the particles occupy only a minor proportion of the viewing surface.
195 Citations
25 Claims
-
1. A method for operating a dielectrophoretic display, the method comprising:
-
providing a dielectrophoretic medium comprising a fluid and a plurality of at least one type of particle within the fluid; providing two electrodes, one disposed on each side of the dielectrophoretic medium; applying to the medium by means of the two electrodes_an electric field having a first frequency, thereby causing the particles to undergo electrophoretic motion and producing a first optical state; and applying to the medium by means of the two electrodes an electric field having a second frequency higher than the first frequency, thereby causing the particles to undergo dielectrophoretic motion and producing a second optical state different from the first optical state, wherein the application of the second frequency electric field is effected by; applying the second frequency electric field for a first period; thereafter applying zero electric field for a period; and thereafter applying the second frequency electric field for a second period, and wherein, during said first and second periods and the intervening period of zero electric field, the electric field of the first frequency is not applied. - View Dependent Claims (2, 3, 4, 7, 8, 9)
-
-
5. A method for operating a dielectrophoretic display, the method comprising:
-
providing a dielectrophoretic medium comprising a fluid and a plurality of at least one type of particle within the fluid; providing two electrodes, one disposed on each side of the dielectrophoretic medium; applying to the medium by means of the two electrodes an electric field having a first frequency, thereby causing the particles to undergo electrophoretic motion and producing a first optical state; and applying to the medium by means of the two electrodes an electric field having a second frequency higher than the first frequency, thereby causing the particles to undergo dielectrophoretic motion and producing a second optical state different from the first optical state, wherein the application of the second frequency electric field is effected by; applying the second frequency electric field for a first period at a first amplitude; thereafter applying the second frequency electric field for a period at a second amplitude less than the first amplitude; and thereafter applying the second frequency electric field for a second period at the first amplitude and wherein, during said first and second periods and the intervening period, the electric field of the first frequency is not applied.
-
-
6. A method for operating a dielectrophoretic display, the method comprising:
-
providing a dielectrophoretic medium comprising a fluid and a plurality of at least one type of particle within the fluid; providing two electrodes, one disposed on each side of the dielectrophoretic medium; applying to the medium by means of the two electrodes an electric field having a first frequency, thereby causing the particles to undergo electrophoretic motion and producing a first optical state; and applying to the medium by means of the two electrodes an electric field having a second frequency higher than the first frequency, thereby causing the particles to undergo dielectrophoretic motion and producing a second optical state different from the first optical state, wherein the application of the second frequency electric field is effected by; applying the second frequency electric field for a first period; thereafter applying for a period an electric field having a frequency less than the second frequency; and thereafter applying the second frequency electric field for a second period and wherein, during said first and second periods and the intervening period, the electric field of the first frequency is not applied.
-
-
10. A method for operating a dielectrophoretic display, the method comprising:
-
providing a dielectrophoretic medium comprising a fluid and a plurality of at least one type of particle within the fluid; applying to the medium an electric field having a first frequency, thereby causing the particles to undergo electrophoretic motion and producing a first optical state; and applying to the medium an electric field having a second frequency higher than the first frequency, thereby causing the particles to undergo dielectrophoretic motion and producing a second optical state different from the first optical state, and wherein the application of the second frequency electric field is effected by; applying the second frequency electric field for a first period; thereafter applying zero electric field for a period; and thereafter applying the second frequency electric field for a second period, and wherein, during said first and second periods and the intervening period of zero electric field, the electric field of the first frequency is not applied. - View Dependent Claims (11, 12, 13)
-
-
14. A method for operating a dielectrophoretic display, the method comprising:
-
providing a dielectrophoretic medium comprising a fluid and a plurality of at least one type of particle within the fluid; applying to the medium an electric field having a first frequency, thereby causing the particles to undergo electrophoretic motion and producing a first optical state; and applying to the medium an electric field having a second frequency higher than the first frequency, thereby causing the particles to undergo dielectrophoretic motion and producing a second optical state different from the first optical state, and wherein the application of the second frequency electric field is effected by; applying the second frequency electric field for a first period at a first amplitude; thereafter applying the second frequency electric field for a period at a second amplitude less than the first amplitude; and thereafter applying the second frequency electric field for a second period at the first amplitude and wherein, during said first and second periods and the intervening period, the electric field of the first frequency is not applied. - View Dependent Claims (15, 16, 17)
-
-
18. A method for operating a dielectrophoretic display, the method comprising:
-
providing a dielectrophoretic medium comprising a fluid and a plurality of at least one type of particle within the fluid; applying to the medium an electric field having a first frequency, thereby causing the particles to undergo electrophoretic motion and producing a first optical state; and applying to the medium an electric field having a second frequency higher than the first frequency, thereby causing the particles to undergo dielectrophoretic motion and producing a second optical state different from the first optical state, and wherein the application of the second frequency electric field is effected by; applying the second frequency electric field for a first period; thereafter applying for a period an electric field having a frequency less than the second frequency; and thereafter applying the second frequency electric field for a second period and wherein, during said first and second periods and the intervening period, the electric field of the first frequency is not applied. - View Dependent Claims (19, 20, 21)
-
-
22. A method for operating a display, the method comprising:
-
providing a medium comprising a fluid and a plurality of at least one type of electrically charged particle within the fluid; providing two electrodes, one disposed on each side of the medium, one of the two electrodes forming a viewing surface for the display; applying to the medium by means of the two electrodes an electric field having a first frequency, thereby causing the particles to undergo electrophoretic motion and producing a first optical state wherein the at least one type of electrically charged particle lies adjacent the viewing surface; and applying to the medium by means of the two electrodes an electric field having a second frequency higher than the first frequency, thereby causing the particles to undergo motion which causes the particles to occupy only a minor portion of the area of the display and producing a second optical state different from the first optical state. - View Dependent Claims (23, 24, 25)
-
Specification