Electro-optical device and method of driving the same

• US 5,852,488 A
• Filed: 12/22/1995
• Issued: 12/22/1998
• Est. Priority Date: 04/28/1992
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Takemura, Yasuhiko
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Duong, Tai V.
• Application Number:
  US08/577,014
• Time in Patent Office: 1,096 Days
• Field of Search: 359/54, 359/57, 359/58, 359/59, 359/67, 349/38, 349/162, 349/39, 349/110, 349/42, 349/122, 349/43, 349/187, 257/59, 257/72, 430/5, 430/20, 430/311, 430/319, 430/321, 437/51, 437/54, 437/59, 437/60, 437/181, 437/228, 437/229, 437/984
• US Class Current: 349/187
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G09G 2320/0209 Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
• CPC Class Codes: G09G 2320/0219 Reducing feedthrough effects in active matrix panels, i.e. voltage changes on the scan electrode influencing the pixel voltage due to capacitive coupling
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes

Abstract

An active matrix display device for suppressing voltage variation ΔV due to off-operation of a gate pulse, including TFTs and picture-element electrodes, at least one of the TFTs being assigned to each picture element, and each of the TFTs having a gate electrode connected to a gate line (first gate line), and a source and a drain one of which is connected to a data line, wherein a picture-element electrode concerned is formed so as to be overlapped with the first gate line through an insulator, and also so as to be overlapped through an insulator with a gate line other than the first gate line or a wiring disposed in parallel to the first gate line.

Claims

1. A method of manufacturing an active-matrix device comprising the steps of:

preparing a transparent substrate;

forming a plurality of gate lines over said substrate;

forming a plurality of thin film transistors over said transparent substrate;

forming a plurality of data lines over said plurality of gate lines in an intersecting relation via an insulating layer, each of said thin film transistors being located at each intersection of said gate lines and said data lines;

forming a light transparent insulating film over said gate and data lines and said thin film transistors, said light transparent insulating film providing a leveled upper surface thereon;

forming a light transparent conductive film on said light transparent insulating film; and

patterning said light transparent conductive film to form a plurality of pixel electrodes arranged in a plurality of regions surrounded by said gate and data lines respectively, where said pixel electrodes are electrically connected to said thin film transistors, respectively,

wherein said light transparent conductive film is patterned by photolithography using said gate and data lines as a photo mask.

7. The method of claims 1, 2, 3, 4, 5, or 6 wherein said gate and data lines comprise a metal and are light non-transparent.

8. The method of claims 1, 2, 3, 4, 5, or 6 wherein said light transparent conductive film comprises indium tin oxide.

9. The method of claims 1, 2, 3, 4, 5, or 6 wherein said plurality of gate lines and said plurality of data lines orthogonally intersect with each other.

10. The method of claim 1 wherein said light transparent insulating film comprises an organic material.

11. The method of claim 1 wherein said light transparent insulating film comprises polyimide.

2. A method of manufacturing an active-matrix device comprising the steps of:

preparing a transparent substrate;

forming a plurality of gate lines over said substrate;

forming a plurality of thin film transistors over said transparent substrate;

forming a plurality of data lines over said plurality of gate lines in an intersecting relation via an insulating layer, said gate and data lines being connected to a gate and one of a source or a drain of said thin film transistors respectively;

forming a light transparent insulating film over said gate and data lines and said thin film transistors, said light transparent insulating film providing a leveled upper surface thereon;

forming a light transparent conductive film on said light transparent insulating film; and

patterning said light transparent conductive film to form a plurality of pixel electrodes arranged in a plurality of regions surrounded by said gate and data lines respectively, where said pixel electrodes are electrically connected to said thin film transistors, respectively,

wherein said light transparent conductive film is patterned by photolithography using said gate and data lines as a photo mask so that each of said plurality of transparent electrodes overlaps said gate and data lines at the periphery thereof.

12. The method of claim 2 wherein said light transparent insulating film comprises an organic material.

13. The method of claim 2 wherein said light transparent insulating film comprises polyimide.

3. A method of manufacturing an active-matrix device having a plurality of thin film transistors arranged in a matrix form, each of said transistors being a bottom gate type in which a gate electrode is located below a channel region, said method comprising the steps of:

preparing a transparent substrate;

forming a plurality of gate lines including gate electrodes of the transistors over said transparent substrate;

forming a plurality of data lines over said gate lines in an intersecting relation via an insulating layer, each of said thin film transistors being located at each intersection of said gate lines and said data lines;

forming a light transparent insulating film over said gate and data lines and said thin film transistors, said light transparent insulating film providing a leveled upper surface thereon;

forming a light transparent conductive film on said light transparent insulating film;

forming a photoresist film on said light transparent conductive film;

exposing portions of said photoresist film to a light using said gate and data lines as a photo mask, said light emitted from a rear side of said substrate opposite to the side over which said photoresist film is formed;

removing unexposed portions of said photoresist film; and

removing portions of said light transparent conductive film below said unexposed portions of the photoresist film to form a plurality of pixel electrodes arranged in a plurality of regions surrounded by said gate and data lines respectively, where said pixel electrodes are electrically connected to said thin film transistors, respectively,

wherein each of said plurality of transparent electrodes overlaps said gate and data lines at the periphery thereof.

14. The method of claim 3 wherein said light transparent insulating film comprises an organic material.

15. The method of claim 3 wherein said light transparent insulating film comprises polyimide.

4. A method of manufacturing an active-matrix device comprising the steps of:

preparing a transparent substrate;

forming a plurality of gate lines over said transparent substrate;

forming a plurality of thin film transistors over said transparent substrate;

forming a plurality of data lines over said plurality of gate lines in an intersecting relation via an insulating layer, each of said thin film transistors being located at each intersection of said gate lines and said data lines;

forming a light transparent insulating film over said gate and data lines and said thin film transistors, said light transparent insulating film providing a leveled upper surface thereon;

forming a light transparent conductive film on said light transparent insulating film; and

patterning said light transparent conductive film to form a plurality of pixel electrodes having a periphery thereof aligned with at least one of said gate or data lines respectively, where said pixel electrodes are electrically connected to said thin film transistors, respectively,

wherein said light transparent conductive film is patterned by photolithography using said at least one of said gate or data lines as a photo mask.

16. The method of claim 4 wherein said light transparent insulating film comprises an organic material.

17. The method of claim 4 wherein said light transparent insulating film comprises polyimide.

5. A method of manufacturing an active-matrix device comprising the steps of:

preparing a transparent substrate;

forming a plurality of gate lines over said substrate;

forming a plurality of thin film transistors over said transparent substrate;

forming a plurality of data lines over said plurality of gate lines in an intersecting relation via an insulating layer, said gate and data lines being connected to a gate and one of a source or a drain of said thin film transistors respectively;

forming a light transparent insulating film over said gate and data lines and said thin film transistors, said light transparent insulating film providing a leveled upper surface thereon;

forming a light transparent conductive film on said light transparent insulating film; and

patterning said light transparent conductive film to form a plurality of pixel electrodes having a periphery thereof aligned with at least one of said gate or data lines respectively, where said pixel electrodes are electrically connected to said thin film transistors, respectively,

wherein said light transparent conductive film is patterned by photolithography using said at least one of said gate or data lines as a photo mask so that each of said plurality of transparent electrodes partially overlaps said at least one of said gate or data lines.

18. The method of claim 5 wherein said light transparent insulating film comprises an organic material.

19. The method of claim 5 wherein said light transparent insulating film comprises polyimide.

6. A method of manufacturing an active-matrix device having a plurality of thin film transistors arranged in a matrix form, each of said transistors being a bottom gate type in which a gate electrode is located below a channel region, said method comprising the steps of:

preparing a transparent substrate;

forming a plurality of gate lines including gate electrodes of the transistors over said transparent substrate;

forming a plurality of data lines over said plurality of gate lines in an intersecting relation via an insulating layer;

forming a light transparent insulating film over said gate and data lines and said thin film transistors, said light transparent insulating film providing a leveled upper surface thereon;

forming a light transparent conductive film on said light transparent insulating film;

forming a photoresist film on said light transparent conductive film;

exposing portions of said photoresist film to a light using at least one of said gate or data lines used as a photo mask;

removing unexposed portions of said photoresist film; and

removing portions of said light transparent conductive film below said unexposed portions of the photoresist film to form a plurality of pixel electrodes having a periphery thereof aligned with at least one of said gate or data lines respectively, where said pixel electrodes are electrically connected to said thin film transistors, respectively,

wherein each of said plurality of transparent electrodes partially overlaps said at least one of the gate or data lines at the periphery thereof.

20. The method of claim 6 wherein said light transparent insulating film comprises an organic material.

21. The method of claim 6 wherein said light transparent insulating film comprises polyimide.