COLOR DISPLAY DEVICE

• US 3,612,758 A
• Filed: 10/03/1969
• Issued: 10/12/1971
• Est. Priority Date: 10/03/1969
• Status: Expired due to Term

• Current Assignee: Harold D. Lees, John L. Dailey, Martin S. Maltz, Paul F. Evans
• Original Assignee: Harold D. Lees, John L. Dailey, Martin S. Maltz, Paul F. Evans
• Inventors: Evans, Paul F., Lees, Harold D., Maltz, Martin S., Dailey, John L.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Martin, John C.
• Application Number:
  US04/863,633
• Time in Patent Office: 739 Days
• Field of Search: 350/160,161,267,266,290 178/7.3D,5.4 315/169TV 204/299
• US Class Current: 348/803
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G09G 2300/06 Passive matrix structure, i.e. with direct application of both column and row voltages to the light emitting or modulating elements, other than LCD or OLED
• CPC Class Codes: G09G 2310/02 Addressing, scanning or driving the display screen or processing steps related thereto
• 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 color display device employing the electrophoretic migration of color pigment particles to form an image on a matrix addressable panel. One coordinate terminal is connected to a line reservoir containing electrophoretic ink particles of a given polarity while the other coordinate terminal is connected to a transparent conductor. The panel is viewed through the transparent conductor side in ambient illumination.

Claims

1. A visual display device comprising:

a colorless insulating fluid containing particles of at least one color pigment in suspension, a substantial amount of said particles having a charge of one polarity;

first electrodes;

second electrodes spaced from said first electrodes, said fluid disposed between said first and second electrodes; and

means for selectively applying an electrical field across individual ones of said first and second electrodes whereby said particles migrate to the electrodes having a polarity opposite to their own causing a color image to be formed on saId electrodes.

2. The apparatus of claim 1 in which said particles have the capability of adhering to said electrodes in imagewise configuration after the removal of said source of potential under the influence of Van der Waals forces.

3. The apparatus of claim 1 in which said fluid is of a contrasting color with said particles.

4. The apparatus of claim 1 further including means to reverse the polarity of the applied field whereby said particles migrate to the opposite electrodes.

5. The apparatus of claim 1 comprising pigment particles of at least two colors in said fluid substantially all of the pigment particles of one color having a negative charge and substantially all of the pigment particles of the other color having a positive charge.

6. The apparatus of claim 1 in which said particles are fluorescent and in which said electrodes are overcoated with a solid insulating layer.

7. The apparatus of claim 1 comprising pigment color particles in said fluid of yellow and blue.

8. The apparatus of claim 1 comprising means for removing said migrated particles from said electrodes by applying a source of potential to said electrodes having a polarity identical to said migrated particles thereon.

9. A visual display device comprising:

a monochromatic fluid dye, particles dispersed in said dye, substantially all of said particles having a charge of a given polarity, first electrodes;

second electrodes spaced from said first electrodes by said dye; and

means for selectively applying a source of potential to individual ones of said first and second electrodes whereby said particles migrate to the electrodes having a polarity opposite to their own in imagewise configuration.

10. A visual panel display device having a depth dimension substantially smaller than its square area dimension comprising:

a dielectric fluid containing particles in suspension, said fluid comprising means for charging triboelectrically substantially all of said particles to a first and second polarity;

first electrodes;

second electrodes spaced from said first electrodes by said fluid; and

means for applying an electrical field across selected ones of said first and second electrodes causing said particles to migrate toward the electrodes having an opposite polarity whereby an image is formed on said electrodes.

11. A visual device comprising:

a first plurality of electrodes comprising spaced conductive elements insulated from each other;

a nonconductive fluid having color pigment particles homogeneously dispersed therein overlying said first electrodes and means for restricting said fluid thereto, substantially all of said particles having a charge of a given polarity;

a second plurality of electrodes comprising spaced transparent conductors positioned angularly to said first electrodes and spaced from said first electrodes by said fluid; and

means for applying an electrical field across selected ones of said first and second electrodes whereby said pigment particles migrate in imagewise configuration to the electrodes having a polarity opposite from their own.

12. A visual panel display device comprising:

a first plurality of electrodes comprising spaced parallel conductive elements insulated from each other;

a dielectric fluid having at least two color pigment particles homogeneously dispersed therein, said pigments of differing color being oppositely charged;

means in said fluid for furnishing a charge of a first or second polarity to individual ones of said particles;

a second plurality of electrodes comprising spaced transparent conductors spaced from said first plurality of electrodes by said fluid and positioned transversely in relation to said first plurality of electrodes; and

means for applying an electrical field across selected ones of said first and second electrodes whereby said charged particles migrate electrophoretically in imagewise configuration to the electrodes having a polarity opposite to their own.

13. The apparatus of claim 12 comprising a multilayer structure on said plurality of first electrodes whereby the threshold migration of said particles is sharpened.

14. The apparatus of claim 13 wherein said multilayer structure includes a selenium layer overlying a layer of aluminum.