ACTIVE-MATRIX DEVICE, ELECTRO-OPTICAL DISPLAY DEVICE, AND ELECTRONIC APPARATUS

• US 20090121226A1
• Filed: 10/20/2008
• Published: 05/14/2009
• Est. Priority Date: 11/09/2007
• Status: Active Grant

• Current Assignee: 138 East LCD Advancements Limited (Vector Capital Corporation)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: NAMOSE, Isamu
• Granted Patent: US 7,692,195 B2
• Time in Patent Office: Days
• US Class Current: 257/59
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• CPC Class Codes: G09G 2300/0465 Improved aperture ratio, e.g. by size reduction of the pixel circuit, e.g. for improving the pixel density or the maximum displayable luminance or brightness
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

An active-matrix device includes a substrate; a plurality of pixel electrodes provided on a first surface of the substrate; a plurality of switching elements provided to correspond to each of the pixel electrodes, each of the switching elements including a fixed electrode connected to the each pixel electrode, a movable electrode mainly made of silicon and displaceably provided so as to contact with and separate from the fixed electrode, and a driving electrode provided to oppose the movable electrode via an electrostatic gap; a first wiring connected to the movable electrode; and a second wiring connected to the driving electrode, wherein a voltage is applied between the movable electrode and the driving electrode to generate an electrostatic attraction between the movable electrode and the driving electrode so as to displace the movable electrode such that the movable electrode contacts with the fixed electrode to electrically connect the first wiring to the pixel electrode.

Claims

1. An active-matrix device, comprising:

a substrate;

a plurality of pixel electrodes provided on a first surface of the substrate;

a plurality of switching elements provided to correspond to each of the pixel electrodes, each of the switching elements including;

a fixed electrode connected to the each pixel electrode;

a movable electrode mainly made of silicon and displaceably provided so as to contact with and separate from the fixed electrode; and

a driving electrode provided to oppose the movable electrode via an electrostatic gap;

a first wiring connected to the movable electrode; and

a second wiring connected to the driving electrode,

wherein a voltage is applied between the movable electrode and the driving electrode to generate an electrostatic attraction between the movable electrode and the driving electrode so as to displace the movable electrode such that the movable electrode contacts with the fixed electrode to electrically connect the first wiring to the pixel electrode.

2. The active-matrix device according to claim 1, wherein the movable electrode includes a silicon layer made of monocrystalline silicon.

3. The active-matrix device according to claim 2, wherein the silicon layer is formed by depositing an amorphous silicon film and then annealing the film.

4. The active-matrix device according to claim 1, wherein the movable electrode is made of silicon carbide.

5. The active-matrix device according to claim 1, wherein the movable electrode is doped with an impurity that improves conductivity of the movable electrode.

6. The active-matrix device according to claim 1, wherein on the movable electrode is formed a thin film made of a material having a conductivity higher than that of silicon.

7. The active-matrix device according to claim 1, wherein the fixed electrode, the movable electrode, and the driving electrode are arranged such that the movable electrode contacts with the fixed electrode while remaining separated from the driving electrode.

8. The active-matrix device according to claim 7, wherein the movable electrode is cantilever-supported to displace a free end side of the movable electrode;

the fixed electrode is located so as to oppose an end region on the free end side of the movable electrode; and

the driving electrode is located relative to the fixed electrode so as to oppose a region on a fixed end side of the movable electrode.

9. The active-matrix device according to claim 1, wherein the pixel electrodes are located in positions different from the switching elements in a thickness direction of the substrate to allow the each pixel electrode to be arranged so as to cover the switching element corresponding to the pixel electrode when two-dimensionally viewed.

10. The active-matrix device according to claim 1, wherein the first wiring includes a plurality of first wirings provided mutually in parallel along the substrate;

the second wiring includes a plurality of second wirings intersecting with the first wirings and provided mutually in parallel along the substrate; and

the each switching element is provided near an intersection between each of the first wirings and each of the second wirings.

11. An electro-optical display device including the active-matrix device according to claim 1.

12. An electronic apparatus including the electro-optical display device according to claim 11.