Electrowetting display

• US 7,167,156 B1
• Filed: 02/26/1999
• Issued: 01/23/2007
• Est. Priority Date: 02/26/1999
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Glass, Thomas R.
• Primary Examiner(s): Chang; Kent
• Application Number:
  US09/258,743
• Time in Patent Office: 2,888 Days
• Field of Search: 345/60, 345/61, 345/71, 345106-107, 359/240, 359/237, 359/238, 359/242, 359/253, 359/263
• US Class Current: 345/107
• CPC Class Codes: G02B 26/005 based on electrowetting
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 3/3433 using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38

Abstract

The present invention comprises construction of a display from display elements that are actuated using the physical principle of electrowetting. In one embodiment, pores within porous silicon are filled with an ionic and an optically reflective electronic conductor, and actuated by application of an electric potential across the pore. An image is then formed on an array of such pores by applying an appropriate voltage to each pore of the array to create an optical image in the light reflected off the electronic conductors. Such a display may be constructed to have very high resolution, making it desirable for creating real-time holographic images, or for creating high-resolution mask images for use in photolithography.

Claims

1. A display comprising:

a substrate comprised of an insulating material having a first surface, and a plurality of pores extending into the substrate from the first surface;

an electronic conductive liquid, deposited within the pores of the substrate;

an ionic conductive liquid, deposited within the pores of the substrate; and

one or more electronic conductors connected to a top or bottom of each of said pores, operable by application of electric potential to cause the electronic conductive liquid to change position within each pore.

2. The display of claim 1 wherein the substrate comprises porous silicon.

3. The display of claim 2 where an interior surface of the pores is oxidized to increase surface resistance.

4. The display of claim 1 wherein the electronic conductive liquid is mercury.

5. The display of claim 1 wherein the ionic conductive liquid is saltwater.

6. The display of claim 1 wherein the substrate is porous polysilicon.

7. A holographic display operable to display a hologram of a three-dimensional image comprising:

a substrate comprised of an insulating material having at least one flat surface, and a plurality of pores extending from the flat surface therein, such that the pores form a matrix of pores with at least 1000 lines of pores per millimeter;

an electronic conductive liquid, deposited within the pores of the substrate;

an ionic conductive liquid, deposited within the pores of the substrate; and

one or more electronic conductors connected to a top or bottom of each of said pores, operable by application of electric potential to cause the electronic conductive liquid to change position within each pore.

8. The holographic display of claim 7 wherein the substrate comprises porous silicon, and wherein an interior surface of the pores is oxidized to increase surface resistance.

9. The holographic display of claim 7 wherein the substrate comprises polysilicon.

10. The holographic display of claim 7 wherein the ionic conductive liquid is saltwater.

11. The holographic display of claim 7 wherein the electronic conductive liquid is mercury.

12. An integrated circuit comprising:

a substrate comprised of an insulating material having at least one flat surface, and a plurality of pores extending from the flat surface therein;

an electronic conductive liquid, deposited within the pores of the substrate;

an ionic conductive liquid, deposited within the pores of the substrate;

one or more electronic conductors connected to a top or bottom of each of said pores, operable by application of electric potential to cause the electronic conductive liquid to change position within each pore; and

electronic circuitry operable to apply an electric potential across a selected pore or group of pores.

13. The integrated circuit of claim 12 wherein the electronic circuitry is operable to select each of the plurality of pores sequentially and apply an electric potential to the selected pore.

14. The integrated circuit of claim 13 wherein the electronic circuitry selects a pore and applies an electric potential to the pore by:

applying voltage to a row select line from a plurality of row select lines in a matrix, such that the voltage turns a row of transistors connected to the row select line on;

applying a voltage to a column select line from a plurality of column select lines in a matrix where each column select line is connected to a column of transistors, such that each column select line is connected to at least one transistor connected to each of the row select lines; and

conducting the voltage applied to the column select line to a conductive pore seal of the selected pore through each transistor that both is connected to the column select line with voltage applied and is turned on by application of voltage to a row select line.

15. The integrated circuit of claim 13 wherein the electronic circuitry selects a pore and applies an electric potential to the pore by:

applying a voltage to a positive or a negative row select line of a pair of row select lines, where the positive row select line is connected to a row of positive transistors and the negative row select line is connected to a row of negative transistors and a voltage applied to the positive row select line turns on the connected positive transistors and a voltage applied to the negative row select line turns on the negative transistors;

applying a positive voltage to a positive column select line and a negative voltage to a negative column select line of a pair of column select lines, where the positive row select line is connected to a column of positive transistors and the negative row select line is connected to a column of negative transistors, such that each pair of column select lines are connected to at least one pair of positive and negative resistors connected to each pair of row select lines; and

conducting the voltage applied to the positive column select line through a positive transistor that both is connected to the positive column select line and is turned on by application of voltage to a positive row select line, or conducting the voltage applied to the negative column select line through a negative transistor that both is connected to the negative column select line and is turned on by application of voltage to a negative row select line, such that the applied voltage is conducted to a conductive pore seal of the selected pore.