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US5373377A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid crystal device with shorting ring and transistors for electrostatic discharge protection

Assignee: Toshiba Corp
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Filing: 1993-02-05
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Granted: 1994-12-13
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Expires: 2013-02-05
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Abstract

Abstract An active matrix type liquid crystal display device with a short-circuiting wire for mutually short-circuiting address wires and data wires through the medium of resistors made of a thin-film transistor is formed along the periphery of a display region on an insulating substrate. The short-circuiting wire is electrically connected inside a region in which the resistors made of a thin-film transistor are formed. In one embodiment, the transistors are surrounded by a portion of the shod circuiting wire. In another embodiment, they are partially surrounded by the wire with a gate electrode which is not protruding out. In another embodiment they are formed with two source and drain regions, one which has a lower breakdown voltage than the other.

Inventors

  • 👤 Meiko Ogawa
  • 👤 Kouhei Suzuki
  • 👤 Hiroaki Kitahara
  • 👤 Shinichi Kimura
  • 👤 Yoshikazu Ichioka

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 23:55
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/136; G02F1/1362; G02F1/136259; G02F1/136204; G02F1/136286; G02F1/1333; G02F1/1335; G02F1/133509; G02F1/133512

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 200 words
A liquid crystal display device comprising: an insulating substrate manifesting an insulating property at least on a surface thereof; a plurality of address wires formed in a display region on said insulating substrate; a plurality of data wires formed to intersect said address wires; first thin-film transistors formed one each at points of intersection of said address wires and data wires and having gate electrodes electrically connected to said address wires and drain electrodes electrically connected to said data wires; picture element electrodes formed one each near said points of intersection and electrically connected to the source electrodes of said first thin-film transistors; and a short-circuiting wire formed along at least part of a periphery of the display region of said insulating substrate and adapted to short-circuit said address wires and data wires to each other through a first resistor made of a second thin-film transistor, said short-circuiting wire formed along at least part of the periphery of the display region of said insulating substrate and being electrically connected such that a portion of said short-circuiting wire surrounds the first resistor made of the second thin-film transistor, a part of the short-circuiting wire being formed inside of the first resistor.
Claim 2
Dependent Claim 200 words
A liquid crystal display device comprising: an insulating substrate manifesting an insulating property at least on a surface thereof; a plurality of address wires formed in a display region on said insulating substrate; a plurality of data wires formed to intersect said address wires; first thin-film transistors formed one each at points of intersection of said address wires and data wires and having gate electrodes electrically connected to said address wires and drain electrodes electrically connected to said data wires; picture element electrodes formed one each near said points of intersection and electrically connected to the source electrodes of said first thin-film transistors; and a short-circuiting wire formed along at least part of a periphery of the display region of said insulating substrate and adapted to short-circuit said address wires and data wires to each other through a first resistor made of a second thin-film transistor, said short-circuiting wire formed along at least part of the periphery of the display region of said insulating substrate and being electrically connected such that a portion of said short-circuiting wire surrounds the first resistor made of the second thin-film transistor, a part of the short-circuiting wire being formed inside of the first resistor.
Claim 3
Dependent Claim 48 words
A liquid crystal display device according to claim 1, wherein said short-circuiting wire is formed in a shape of a ladder along the periphery of said insulating substrate, and the first resistors made of the second thin-film transistor are formed as openings in the ladder shaped short-circuiting wire.
Claim 4
Dependent Claim 48 words
A liquid crystal display device according to claim 1, wherein a magnitude of resistance of said first resistor made of the second thin-film transistor is set in a range between 10 kΩ and 100 MΩ when a potential difference between opposite terminals of said first resistor is 20V.
Claim 5
Dependent Claim 14 words
A liquid crystal display device according to claim 1, further comprising an auxiliary capacitance.
Claim 6
Dependent Claim 34 words
A liquid crystal display device according to claim 4, wherein an auxiliary capacitance line for each auxiliary capacitance is connected to said short-circuiting wire through a second resistor made of a third thin-film transistor.
Claim 7
Dependent Claim 202 words
A liquid crystal display device comprising: an insulating substrate manifesting an insulating property at least on a surface thereof; a plurality of address wires formed in a display region on said insulating substrate; a plurality of data wires formed to intersect said address wires; first thin-film transistors formed one each at points of intersection of said address wires and data wires and having gate electrodes electrically connected to said address wires and drain electrodes electrically connected to said data wires; picture element electrodes formed one each near said points of intersection and electrically connected to the source electrodes of said first thin-film transistors; and a short-circuiting wire formed along at least part of a periphery of the display region of said insulating substrate and adapted to short-circuit said address wires and data wires to each other through a first resistor made of a second thin-film transistor; wherein said second thin-film transistor has a first part of opposite source and drain electrodes and a second part of opposite source and drain electrodes distinct from said first part, the second part of opposite source and drain electrodes being more easily broken by static electricity than the first part of opposite source and drain electrode.
Claim 8
Dependent Claim 202 words
A liquid crystal display device comprising: an insulating substrate manifesting an insulating property at least on a surface thereof; a plurality of address wires formed in a display region on said insulating substrate; a plurality of data wires formed to intersect said address wires; first thin-film transistors formed one each at points of intersection of said address wires and data wires and having gate electrodes electrically connected to said address wires and drain electrodes electrically connected to said data wires; picture element electrodes formed one each near said points of intersection and electrically connected to the source electrodes of said first thin-film transistors; and a short-circuiting wire formed along at least part of a periphery of the display region of said insulating substrate and adapted to short-circuit said address wires and data wires to each other through a first resistor made of a second thin-film transistor; wherein said second thin-film transistor has a first part of opposite source and drain electrodes and a second part of opposite source and drain electrodes distinct from said first part, the second part of opposite source and drain electrodes being more easily broken by static electricity than the first part of opposite source and drain electrode.
Claim 9
Dependent Claim 42 words
A liquid crystal display device according to claim 6, wherein said second thin-film transistors are comb-shaped having the first part of opposite source and drain electrodes as fingers and said short-circuiting wire is comb-shaped and interleaved with the comb-shaped second thin-film transistor.
Claim 10
Dependent Claim 36 words
A liquid crystal display device according to claim 7, wherein the fingers of said comb-shaped source electrodes and drain electrodes are electrically connected to a bus bar formed in a lower layer through separate through holes.
Claim 11
Dependent Claim 42 words
A liquid crystal display device according to claim 8, wherein a gate electrode of the first resistor made of the second thin-film transistor has a square shape and said gate electrode covers the fingers of said comb-shaped source electrodes and drain electrodes.
Claim 12
Dependent Claim 30 words
A liquid crystal display device according to claim 6, wherein a-Si is a component element of said first resistor made of the second thin-film transistor and has a rectangular shape.
Claim 13
Dependent Claim 48 words
A liquid crystal display device according to claim 6, wherein a magnitude of resistance of the first resistor made of the second thin-film transistor is set in a range between 10 kΩ and 100 MΩ when a potential difference between opposite terminals of said first resistor is 20V.
Claim 14
Dependent Claim 14 words
A liquid crystal display device according to claim 6, further comprising an auxiliary capacitance.
Claim 15
Dependent Claim 34 words
A liquid crystal display device according to claim 12, wherein an auxiliary capacitance wire for each auxiliary capacitance is connected to said short-circuiting wire through a second resistor made of a third thin-film transistor.
Claim 16
Dependent Claim 168 words
A liquid crystal display device comprising: an insulating substrate manifesting an insulating property at least on a surface thereof; a plurality of address wires formed in a display region on said insulating substrate; a plurality of data wires formed to intersect said address wires; first thin-film transistors formed one each at points of intersection of said address wires and data wires and having gate electrodes electrically connected to said address wires and drain electrodes electrically connected to said data wires; picture element electrodes formed one each near said points of intersection and electrically connected to source electrodes of said first thin-film transistors; and a short-circuiting wire formed along at least part of a periphery of the display region of said insulating substrate and adapted to short-circuit said address wires and data wires to each other through a first resistor made of a second thin-film transistor, wherein the short-circuiting wire surrounds the second thin-film transistor except that a gate-electrode of the second thin-film transistor protrudes outside the short-circuiting wire.
Claim 17
Dependent Claim 168 words
A liquid crystal display device comprising: an insulating substrate manifesting an insulating property at least on a surface thereof; a plurality of address wires formed in a display region on said insulating substrate; a plurality of data wires formed to intersect said address wires; first thin-film transistors formed one each at points of intersection of said address wires and data wires and having gate electrodes electrically connected to said address wires and drain electrodes electrically connected to said data wires; picture element electrodes formed one each near said points of intersection and electrically connected to source electrodes of said first thin-film transistors; and a short-circuiting wire formed along at least part of a periphery of the display region of said insulating substrate and adapted to short-circuit said address wires and data wires to each other through a first resistor made of a second thin-film transistor, wherein the short-circuiting wire surrounds the second thin-film transistor except that a gate-electrode of the second thin-film transistor protrudes outside the short-circuiting wire.
Claim 18
Dependent Claim 44 words
A liquid crystal display device according to claim 14, wherein the gate electrode of the second thin-film transistor is protruded from said short-circuiting wire by causing a part of said short-circuiting wire near the gate electrode to be formed in an inwardly depressed shape.
Claim 19
Dependent Claim 23 words
A liquid crystal display device according to claim 14, wherein said gate electrode of the second thin-film transistor is possessed of a constriction.
Claim 20
Dependent Claim 20 words
A liquid crystal display device according to claim 14, wherein the gate electrode of the second thin-film transistor is tapered.
Claim 21
Dependent Claim 30 words
A liquid crystal display device according to claim 14, wherein the gate electrode of the second thin-film transistor is connected to a ring made of a-Si outside said short-circuiting wire.
Claim 22
Dependent Claim 48 words
A liquid crystal display device according to claim 14, wherein a magnitude of resistance of said first resistor made of the second thin-film transistor is set in a range between 10 kΩ and 100 MΩ when a potential difference between opposite terminals of said first resistor is 20V.
Claim 23
Dependent Claim 14 words
A liquid crystal display device according to claim 14, further comprising an auxiliary capacitance.
Claim 24
Dependent Claim 34 words
A liquid crystal display device according to claim 20, wherein an auxiliary capacitance wire for each auxiliary capacity is connected to said short-circuiting wire through a second resistor made of a third thin-film transistor.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-12-12 1998-06-13 1998-12-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-12-12 2002-06-13 2002-12-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-12-12 2006-06-13 2006-12-13 $7700.00 Window Closed / Lapsed

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