Plane display

• US 5,283,566 A
• Filed: 04/15/1992
• Issued: 02/01/1994
• Est. Priority Date: 04/06/1988
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ono, Kikuo, Mimura, Akio, Yoshimura, Masao, Suzuki, Takashi, Konishi, Nobutake, Ohwada, Jun-ichi
• Primary Examiner(s): Weldon, Ulysses
• Assistant Examiner(s): WU, XIAO MIN
• Application Number:
  US07/869,085
• Time in Patent Office: 657 Days
• Field of Search: 340/784, 340/719, 340/718, 340/811, 359/54, 359/55, 359/57, 359/58, 359/59, 359/87
• US Class Current: 345/211
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode

Abstract

A plane display includes a plurality of pixel capacitors, each of which includes first and second electrodes and a non-linear optical material disposed therebetween. A plurality of storage capacitors are respectively provided in association with the plurality of pixel capacitors, each of which includes the first electrode of the corresponding pixel capacitor, an insulating film, and a third electrode insulated from the first electrode through the insulating film and connected to an external power supply terminal. Additionally, a provided for each storage capacitor and connected between the third electrode of the associated storage capacitor and the external power supply terminal, for preventing a potential drop causable in the course of storing electric charge in the associated storage capacitor.

Claims

1. A plane display comprising:

a plurality of pixel capacitors disposed in rows and columns within a display region of said plane display, each pixel capacitor including first and second electrodes and a non-linear optical material disposed therebetween, the first electrode of each pixel capacitor having a transparent part;

a plurality of thin film transistors connected to said first electrodes of said plurality of pixel capacitors, respectively, for selectively energizing said pixel capacitors;

a plurality of storage capacitors disposed in rows and columns within the display region and respectively provided in association with said plurality of pixel capacitors and each including a third electrode having a transparent part facing to the transparent part of the first electrode of the associated pixel capacitor with an insulating film therebetween so as to provide a storage capacitance in cooperation with the transparent part of said first electrode facing thereto; and

means for applying a given electrical potential to each of the third electrodes of said plurality of storage capacitors and including an auxiliary conductive layer through display portions of selected pixels within the display region and made of a metallic material which is electrically connected and physically in direct connection with the transparent parts of the third electrodes of the storage capacitors associated with the pixel capacitors of said selected pixels.

2. A plane display according to claim 1 wherein the effective area of said first electrode excludes a laminated portion of said third electrode of the associated storage capacitor and said auxiliary conductive layer.

3. A plane display according to claim 1 wherein said auxiliary conductive layer is disposed on one side of each of the parts of the third electrodes with which said conductive layer is connected, said one side being opposite to a side of the part facing to said first electrode.

4. A plane display according to claim 3 wherein the effective area of said first electrode excludes a laminated portion of said third electrode of the associated storage capacitor and said auxiliary conductive layer.

5. A plane display according to claim 1 wherein said plurality of pixel capacitors disposed in the rows are sequentially scanned row by row in a predetermined time relationship through scanning lines respectively associated with said rows, said auxiliary conductive layer associated with each row is disposed substantially parallel to said scanning line associated with the row.

6. A plane display according to claim 5 wherein the effective area of said first electrode excludes a laminated portion of said third electrode of the associated storage capacitor and said auxiliary conductive layer.

7. A plane display according to claim 1 wherein said first and third electrodes are made of a material containing indium oxide as main constituent, and said auxiliary conductive layer is made of a material containing aluminum as main constituent.

8. A plane display according to claim 1, further comprising a substrate on which each of said pixel capacitors, the thin film transistor connected to the first electrode of the pixel capacitor, the storage capacitor associated with the pixel capacitor and the auxiliary conductive layer in direct connection with the transparent part of the third electrode of the storage capacitor are formed and said auxiliary conductive layer being disposed between said substrate and the transparent part of the third electrode of said storage capacitor.

9. A plane display comprising:

a plurality of pixel capacitors disposed in rows and columns within a display region of said plane display to be scanned in a predetermined time relationship;

a plurality of storage capacitors disposed in rows and columns within the display region and respectively provided in association with said pixel capacitors, each storage capacitor having a transparent electrode which is facing to a transparent part of one of the electrodes forming the associated pixel capacitor so as to provide a storage capacitance therebetween inside a region of the corresponding pixel capacitor; and

wiring means including a plurality of auxiliary conductive layers, each extending through display portions of selected pixels within the display region and arranged to be laminous with the transparent electrode of each of the storage capacitors associated with said selected pixels and made of a metallic material for permitting each storage capacitor to be written within an interval of time which is not longer than the scanning time for each pixel capacitor.

10. A plane display according to claim 9 wherein said plurality of pixel capacitors are arranged in rows and columns, the pixel capacitors lined up in each row are connected in common to a scanning line, the pixel capacitors lined up in each column are connected in common to a signal line, and at least one of said scanning and signal lines is made of the same material as that of said conductive layer.

11. A plane display according to claim 9 wherein one of the electrodes of each storage capacitor has one portion made of the same conductive material as that of one of electrodes of said pixel capacitor and another portion made of a conductive material different from that of said one electrode of said pixel capacitor.

12. A plane display according to claim 9 wherein said plurality of pixel capacitors are arranged in matrix.

13. A plane display according to claim 9, further comprising a substrate on which each of said pixel capacitors, the storage capacitor associated with the pixel capacitor and the auxiliary conductive layer which is laminous with the transparent electrode of the storage capacitor are formed and said auxiliary conductive layer being disposed between said substrate and the transparent part of the third electrode of said storage capacitor.

14. A video signal display system having a plane display comprising:

a plurality of pixel capacitors disposed in rows and columns within a display region of said plane display, each pixel capacitor including first and second electrodes and a non-linear optical material disposed therebetween, the first electrode of each pixel capacitor having a transparent part;

a plurality of thin film transistors connected to said first electrodes of said plurality of pixel capacitors, respectively, for selectively energizing said pixel capacitors;

a plurality of storage capacitors disposed in rows and columns within the display region and respectively provided in association with said plurality of pixel capacitors and each including a third electrode having a transparent part facing to the transparent part of the first electrode of the associated pixel capacitor with an insulating film therebetween so as to provide a storage capacitance in cooperation with the transparent part of said first electrode facing thereto; and

means for applying a given electrical potential to each of the third electrodes of said plurality of storage capacitors and including an auxiliary conductive layer extending through the display portions of selected pixels within the display region and made of a metallic material which is electrically connected and physically in direct connection with the transparent parts of the third electrodes of the storage capacitors associated with the pixel capacitors of said selected pixels.

15. A video signal display system according to claim 14, further comprising;

a substrate on which each of the pixel capacitors, the thin film transistor connected to the first electrode of the pixel capacitor, the storage capacitor associated with the pixel capacitor and the auxiliary conductive layer in direct connection with the transparent part of the third electrode of the storage capacitor are formed and said auxiliary conductive layer being disposed between said substrate and the transparent part of the third electrode of said storage capacitor.

16. A projection type video signal system having a plane display comprising:

a plurality of pixel capacitors disposed in rows and columns within a display region of said plane display, each pixel capacitor including first and second electrodes and a non-linear optical material disposed therebetween, the first electrode of each pixel capacitor having a transparent part;

a plurality of thin film transistors connected to said first electrodes of said plurality of pixel capacitors, respectively, for selectively energizing said pixel capacitors;

a plurality of storage capacitors disposed in rows and columns within the display region and respectively provided in association with said plurality of pixel capacitors and each including a third electrode having a transparent part facing to the transparent part of the first electrode of the associated pixel capacitor with an insulating film therebetween so as to provide a storage capacitance in cooperation with the transparent part of said first electrode facing thereto; and

means for applying a given electrical potential to each of the third electrodes of said plurality of storage capacitors and including an auxiliary conductive layer extending through display portions of selected pixels within the display region and made of a metallic material which is electrically connected and physically in direct connection with the transparent parts of the third electrodes of the storage capacitors associated with the pixel capacitors of said selected pixels.

17. A projection type video signal system according to claim 16, further comprising;

a substrate on which each of said pixel capacitors, the thin film transistor connected to the first electrode of the pixel capacitor, the storage capacitor associated with the pixel capacitor and the auxiliary conductive layer in direct connection with the transparent part of the third electrode of the storage capacitor are formed such that said auxiliary conductive layer being disposed between the transparent part of third electrode of said storage capacitor and said substrate.

18. A method of making a plane display comprising a plurality of pixel capacitors disposed within a display region, each pixel capacitor having two pixel electrodes and a plurality of storage capacitors provided to said pixel capacitors, respectively, each of said storage capacitors having two auxiliary electrodes, one of which is connected to one of said pixel electrodes, the other auxiliary electrode being connected to an auxiliary conductor to be connected to a predetermined potential, said method comprising the steps of:

forming a first layer of metallic material to extend within said display region through display portions of selected pixel capacitors, said first layer serving as the auxiliary conductor to which the other auxiliary electrodes of the storage capacitors provided to the selected pixel capacitors are to be connected; and

laminating on said first layer a transparent layer of a second conductive material and forming a third layer so as to provide a capacitance in cooperation with said second transparent layer, while connecting said first layer to a fixed potential, said second layer serving as the other auxiliary electrode and said capacitance provided by said second and third layers serving as the storage capacitor.