Liquid crystal display with a scanning line having a ring shaped redundant section and method for fabricating the same

• US 5,831,708 A
• Filed: 08/30/1996
• Issued: 11/03/1998
• Est. Priority Date: 09/28/1995
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Tagusa, Yasunobu, Hishida, Tadanori, Hiraishi, Youichi
• Primary Examiner(s): Gross, Anita Pellham
• Assistant Examiner(s): CHOWDHURY, TARIFUR RASHID
• Application Number:
  US08/705,759
• Time in Patent Office: 795 Days
• Field of Search: 349/54, 349/143, 349/55, 349/38, 349/39, 349/148
• US Class Current: 349/143
• CPC Class Codes: G02F 1/1333 Constructional arrangements; Manufacturing methodsG02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/1343 Electrodes reflective electrodes G02F1/133553
• CPC Class Codes: G02F 1/136 Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit G02F1/135 takes precedence
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136259 Repairing; Defects
• CPC Class Codes: G02F 1/136263 Line defects
• CPC Class Codes: G02F 1/136272 Auxiliary lines
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence

Abstract

On an active matrix substrate having a TFT in the vicinity of the intersection of a gate line and a source line and a pixel electrode connected to the TFT, an inter-layer insulating film is formed by an acrylic resin, for example, between the pixel electrode and the gate line, source line and TFT. The pixel electrode does not overlap a self gate line, but overlaps a gate line adjacent to the self gate line. At least one of the gate line and the source line has a redundant structure including ring-shaped sections connected in a longitudinal direction so as to provide redundancy as a measure to counter the disconnection of lines.

Claims

1. A liquid crystal display element comprising:

a switching element in a vicinity of an intersection of a scanning line and a signal line; and

a pixel electrode connected to said switching element, said pixel electrode having an extended section for covering a space between adjacent scanning lines,

wherein at least one of said scanning line and said signal line has ring-shaped redundant sections, and

an inter-layer insulating film is provided between said pixel electrode and said scanning line, signal line and switching element.

2. The liquid crystal display element according to claim 1,

wherein said inter-layer insulating film is made of an organic resin.

3. The liquid crystal display element according to claim 2,

wherein said organic resin is an acrylic resin.

4. The liquid crystal display element according to claim 1,

wherein said scanning line has a metal oxide film on a surface thereof.

5. The liquid crystal display element according to claim 1,

wherein said pixel electrode is made of ITO, and

said inter-layer insulating film is made of a material exhibiting heat resistance at 200°

C. or higher temperatures.

6. The liquid crystal display element according to claim 1,

wherein adjacent redundant sections are connected to each other with more than one connection line.

7. The liquid crystal display element according to claim 1,

wherein adjacent redundant sections are connected to each other with one connection line.

8. The liquid crystal display element according to claim 1,

wherein adjacent redundant sections have a common portion.

9. The liquid crystal display element according to claim 1,

wherein said scanning line has ring-shaped redundant sections, and

a portion of said redundant section, which is parallel to said signal line, has a line width equal to or smaller than a line width of said signal line.

10. The liquid crystal display element according to claim 1,

wherein said scanning line has ring-shaped redundant sections,

one of portions of said redundant section which portions cross said signal line at right angles is made thicker than the other portion, and

said inter-layer insulating film located on said one portion has a contact hole through which said switching element and said pixel electrode are electrically connected.

11. The liquid crystal display element according to claim 1,

wherein an insulating film for forming a storage capacitor is provided between said scanning line and a contact electrode of said switching element.

12. The liquid crystal display element according to claim 1, further comprising a light blocking film, made of the same material as said signal line, for blocking light between adjacent scanning lines.

13. The liquid crystal display element according to claim 1,

wherein a contact electrode of said switching element has an extended section for covering a space between adjacent scanning lines.

14. The liquid crystal display element according to claim 1,

wherein said scanning line has ring-shaped redundant sections, and

a portion of said redundant section, which is parallel to said signal line, lies under said signal line.

15. The liquid crystal display element according to claim 14,

wherein a gate insulating film made of SiO₂ is provided between said signal line and the portion of said redundant section, which is parallel to said signal line.

16. The liquid crystal display element according to claim 1,

wherein said scanning line has ring-shaped redundant sections, and

a capacitor line for forming a storage capacitor is provided on a portion of said redundant section, which crosses said signal line at a right angle.

17. The liquid crystal display element according to claim 16,

wherein said capacitor line is made of the same material as said signal line.

18. The liquid crystal display element according to claim 16,

wherein said capacitor line has on a surface thereof an oxide film formed by anodic oxidation.

19. The liquid crystal display element according to claim 1,

wherein one extra line is provided for each signal line to be parallel to said signal line, and said signal line and said extra line are connected to each other with a connection line.

20. The liquid crystal display element according to claim 19,

wherein said connection line is made of ITO.

21. The liquid crystal display element according to claim 19,

wherein said signal line and said extra line are arranged on both sides of said pixel electrode.

22. A liquid crystal display element, comprising:

a switching element in a vicinity of an intersection of a scanning line and a signal line, said scanning line having ring-shaped redundant sections; and

a pixel electrode connected to said switching element, said pixel electrode not overlapping a self scanning line and having a portion which overlaps a scanning line adjacent said self scanning line,

an inter-layer insulating film is provided between said pixel electrode and said scanning line, signal line and switching element, and wherein

said inter-layer insulating film has a contact hole through which said switching element and said pixel electrode are electrically connected above a portion of said redundant section, which crosses said signal line at a right angle.

23. A liquid crystal display element comprising:

a switching element in a vicinity of an intersection of a scanning line and a signal line, said scanning line being formed in a layer higher than said signal line; and

a pixel electrode connected to said switching element,

wherein at least one of said scanning line and said signal line has ring-shaped redundant sections, and

an inter-layer insulating film is provided between said pixel electrode and said scanning line, signal line and switching element.

24. A liquid crystal display element comprising:

a switching element in a vicinity of an intersection of a scanning line and a signal line;

an inter-layer insulating film placed on said switching element;

a pixel electrode which is formed on said inter-layer insulating film and connected to said switching element; and

an auxiliary electrode formed on said inter-layer insulating film to cover said switching element.

25. The liquid crystal display element according to claim 24,

wherein said auxiliary electrode is made of the same material as said pixel electrode.

26. The liquid crystal display element according to claim 24,

wherein said auxiliary electrode is connected to a scanning line which is adjacent to said auxiliary electrode.

27. A liquid crystal display device comprising:

an active matrix substrate having a switching element in a vicinity of an intersection of a scanning line and a signal line, and a pixel electrode connected to said switching element, said pixel electrode having an extended section covering a space between adjacent scanning lines;

a counter substrate; and

a liquid crystal sandwiched between said active-matrix substrate and said counter substrate,

wherein said scanning line has ring-shaped redundant sections, and

an inter-layer insulating film is formed between said pixel electrode and said scanning line, signal line and switching element.

28. The liquid crystal display device according to claim 27, further comprising a signal input circuit for inputting a signal of an opposite polarity to a signal line every horizontal period.

29. The liquid crystal display device according to claim 27, further comprising a signal input circuit for inputting signals of opposite polarities to adjacent signal lines, respectively.

30. The liquid crystal display device according to claim 27, further comprising a signal input circuit for inputting signals of opposite polarities to adjacent signal lines, respectively, and for inverting the polarity of the signal every horizontal period.

31. A method for fabricating a liquid crystal display element in which at least one of a scanning line and a signal line has ring-shaped redundant sections, comprising the steps of:

forming a scanning line, a signal line, and a switching element on a substrate;

forming an inter-layer insulating film having a contact hole therein by applying a resin to cover said scanning line, said signal line, and said switching element and to form a predetermined pattern; and

forming a pixel electrode on said inter-layer insulating film and in said contact hole and covering a space between adjacent scanning lines with an extended section of the pixel electrode.

32. The method for fabricating a liquid crystal display element according to claim 31, further comprising the step of applying an ashing treatment to a surface of said inter-layer insulating film.

33. The method for fabricating a liquid crystal display element according to claim 31, further comprising the step of irradiating light on a surface of said inter-layer insulating film.

34. The method for fabricating a liquid crystal display element according to claim 31,

wherein a colored resin is used as a material of said inter-layer insulating film, and

said method further comprises the step of applying a treatment for making the resin transparent after forming said inter-layer insulating film.

35. The method for fabricating a liquid crystal display element according to claim 31, further comprising the steps of:

forming an insulating film to cover said scanning line;

removing said insulating film on a portion of said scanning line; and

forming a capacitor line on the portion of said scanning line from which said insulating film is removed using the same material as said signal line simultaneously with the formation of said signal line.

36. The method for fabricating a liquid crystal display element according to claim 35, further comprising the step of applying anodic oxidation to said capacitor line.

37. A method for fabricating a liquid crystal display element including a switching element in a vicinity of an intersection of a scanning line and a signal line, comprising the steps of:

forming said scanning line, signal line, and switching element on a substrate;

forming an inter-layer insulating film having a contact hole therein by applying a resin exhibiting heat resistance at 200°

C. or higher temperatures so as to cover said scanning line, signal line and switching element and form a predetermined pattern; and

forming a pixel electrode made of ITO on said inter-layer insulating film and in said contact hole,

wherein the step of forming said pixel electrode includes a heating treatment at 200°

C. or higher temperatures.

38. A liquid crystal display element comprising:

a switching element in a vicinity of an intersection of a scanning line and a signal line; and

a pixel electrode connected to said switching element,

wherein at least one of said scanning line and said signal line has ring-shaped redundant sections,

an inter-layer insulating film is provided between said pixel electrode and said scanning line, signal line and switching element,

one extra line is provided for each signal line to be parallel to said signal line, and said signal line and said extra line are connected to each other with a connection line, and

said connection line is extended from a connected section of said signal line and said switching element to cover a space between a scanning line on which said switching element is formed and a scanning line adjacent to said scanning line.

39. A liquid crystal display element comprising:

a switching element in a vicinity of an intersection of a scanning line and a signal line; and

a pixel electrode connected to said switching element, said pixel electrode having an extended section for covering a top of the switching element,

wherein at least one of said scanning line and said signal line has ring-shaped redundant sections, and

an inter-layer insulating film is provided between said pixel electrode and said scanning line, signal line and switching element.