Active matrix type liquid crystal display apparatus with conductive light shield element

• US 6,075,580 A
• Filed: 12/21/1994
• Issued: 06/13/2000
• Est. Priority Date: 12/28/1993
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kouchi, Tetsunobu
• Primary Examiner(s): Abraham, Fetsum
• Application Number:
  US08/361,182
• Time in Patent Office: 2,001 Days
• Field of Search: 349/42-44, 349/110, 349/111, 349/143, 349/116, 257/59, 257/72
• US Class Current: 349/110
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode

Abstract

An active matrix type liquid crystal display apparatus includes a liquid crystal layer disposed between a device substrate and an opposite substrate wherein the device substrate includes: a plurality of switching elements disposed at a plurality of locations determined by data signal interconnections and scanning signal interconnections; and a plurality of pixel electrodes disposed at locations corresponding to the plurality of switching elements, the plurality of pixel elements being connected to the corresponding switching elements, and wherein the opposite substrate includes an opposite electrode disposed opposite to the pixel electrodes, the active matrix type liquid crystal display apparatus being characterized in that: a light shielding layer having electrical conductivity is disposed at least partially on the data signal interconnections or the scanning signal interconnections via an insulating layer; the pixel electrodes are disposed on the light shielding layer via a second insulating layer; and a voltage is applied to the light shielding layer.

Claims

1. A method of producing a device substrate for use in an active matrix type liquid crystal display apparatus, in which the device substrate is arranged opposite a common electrode substrate with a layer of liquid crystal material therebetween, said device substrate having on a base substrate:

a plurality of switching elements disposed at a plurality of locations determined by the crossing of data signal lines and scanning signal lines;

a plurality of pixel electrodes disposed at locations corresponding to said plurality of switching elements, said plurality of pixel electrodes being connected to the corresponding switching elements, and wherein a conductive light shielding layer is disposed at least partially on said data signal lines and said scanning signal lines with an insulating layer therebetween, and wherein said pixel electrodes is disposed at least partially on said conductive light shielding layer with a second insulating layer therebetween, and means for applying a voltage to said light shielding layer, the method comprising steps of;

providing the base substrate having thereon said switching elements, said data signal lines, said scanning signal lines and said voltage applying means;

forming said insulating layer on said switching elements, said data signal lines, said scanning signal lines and said voltage applying means;

forming said light shielding layer on said insulating layer;

forming said second insulating layer on said light shielding layer and on said insulating layer;

opening contact holes in said second insulating layer and in said insulating layer to expose said voltage applying means and a contact portion of each of said switching elements;

opening a contact hole in said second insulating layer to expose said light shielding layer, and

depositing conductive material for forming said pixel electrodes in contact with the corresponding contact portion of each of the corresponding switching elements and for forming, at the same time, a connection between said light shielding layer and said voltage applying means by a conductor through the contact hole in said second insulating layer.

2. A method of producing an active matrix liquid crystal display apparatus comprising steps of:

producing a device substrate by the method of claim 1;

providing a common electrode substrate;

arranging said device substrate and said common electrode substrate with said pixel electrodes facing the common electrode of said common electrode substrate; and

sealing a layer of liquid crystal material between said device substrate and said common electrode substrate.

3. A device substrate for use in an active matrix type liquid crystal display apparatus, said device substrate comprising:

a base substrate bearing a plurality of switching elements disposed at a plurality of locations determined by the crossing of data signal lines and scanning signal lines, a plurality of pixel electrodes disposed at locations corresponding to said plurality of switching elements, said plurality of pixel electrodes being connected to the corresponding switching elements;

a conductive light shielding layer disposed at least partially on said data signal lines and said scanning signal lines with an insulating layer therebetween;

a second insulating layer disposed between said pixel electrodes and said light shielding layer, wherein said pixel electrodes are arranged to overlap said light shielding layer; and

means for applying a voltage to said light shielding layer, wherein

said voltage applying means and said light shielding layer are electrically connected by a connection member of the same material as that of said pixel electrodes.

4. An active matrix type liquid crystal display apparatus comprising:

the device substrate of claim 3;

a common electrode substrate arranged with its common electrode arranged facing the pixel electrodes of said device substrate, and

a layer of liquid crystal material sealed between said device substrate and said common electrode substrate.

5. An active matrix type liquid crystal display apparatus according to claim 4, wherein said light shielding layer comprises Al, TaN, or TiN.

6. An active matrix type liquid crystal display apparatus according to claim 4, wherein said switching elements are thin film transistors.

7. An active matrix type liquid crystal display apparatus according to claim 4, wherein said light shielding layer is maintained at a fixed potential.

8. An active matrix type liquid crystal display apparatus according to claim 4, wherein a voltage corresponding to the voltage of said plurality of pixel electrode is applied to said light shielding layer.

9. An active matrix type liquid crystal display apparatus according to claim 4, wherein said light shielding layer is disposed on the same side on which said pixel electrodes are located with respect to said switching elements.

10. An active matrix type liquid crystal display apparatus according to claim 4, wherein the voltage applied to said common electrode is varied periodically.

11. A device substrate for use in an active matrix type liquid crystal display according to claim 3, wherein said light shielding layer comprises Al, TaN, or TiN.

12. A device substrate for use in an active matrix type liquid crystal display according to claim 3, wherein said switching elements are thin film transistors.

13. A device substrate for use in an active matrix type liquid crystal display according to claim 3, wherein said light shielding layer is maintained at a fixed potential.

14. A device substrate for use in an active matrix type liquid crystal display according to claim 3, wherein a voltage corresponding to the voltage of said plurality of pixel electrode is applied to said light shielding layer.

15. A device substrate for use in an active matrix type liquid crystal display according to claim 3, wherein said light shielding layer is disposed on the same side on which said pixel electrodes are located with respect to said switching elements.