Patent US5266825A successfully refreshed from Google Patents.
US5266825A
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US
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Thin-film device
Assignee: Hitachi Ltd
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Filing: 1992-04-07
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Granted: 1993-11-30
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Expires: 2012-04-07
Abstract
Abstract A thin-film transistor using hydrogenated amorphous silicon (a-Si:H), and particularly a thin-film device such as a thin-film transistor having high conductivity, large drivability and high process margin, and a display panel using the same transistors. The object of the invention is to reduce defects due to shorts between the gate and the source or between the gate and the drain, to prevent signal line defect even in case defects develop due to shorts, and to expand the design margin and process margin in the array. A capacity is connected to the gate electrode of the channel side and a voltage is applied to the gate electrode via the capacity.
Inventors
- 👤 Toshihisa Tsukada
- 👤 Yoshiyuki Kaneko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:52
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/67; H10D30/6729; H10D30/6737; H10D30/6704; H10D30/673; H10D30/674; H10D30/6741; H10D30/6743
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
155 words
A display panel comprising: a substrate, a plurality of thin-film transistors formed on the substrate, and a liquid crystal formed on the substrate, wherein each of said plurality of thin-film transistors includes: a gate electrode, a chanel region consisting of a semiconductor layer, a gate insulator formed between the gate electrode and the semiconductor layer, and a source electrode and a drain electrode formed on said semiconductor layer, wherein said gate electrode has a first gate electrode and a second gate electrode which are electrically insulated from each other, said first gate electrode being provided overlying said second gate electrode such that a coupling capacitance can be provided between the first and second gate electrodes, and a signal is applied to the second gate electrode so as to apply the signal to the first gate electrode via the coupling capacitance, the coupling capacitance being formed at least at a location away from the channel region.
Claim 2
Dependent Claim
155 words
A display panel comprising: a substrate, a plurality of thin-film transistors formed on the substrate, and a liquid crystal formed on the substrate, wherein each of said plurality of thin-film transistors includes: a gate electrode, a chanel region consisting of a semiconductor layer, a gate insulator formed between the gate electrode and the semiconductor layer, and a source electrode and a drain electrode formed on said semiconductor layer, wherein said gate electrode has a first gate electrode and a second gate electrode which are electrically insulated from each other, said first gate electrode being provided overlying said second gate electrode such that a coupling capacitance can be provided between the first and second gate electrodes, and a signal is applied to the second gate electrode so as to apply the signal to the first gate electrode via the coupling capacitance, the coupling capacitance being formed at least at a location away from the channel region.
Claim 3
Dependent Claim
37 words
A display panel according to claim 1 wherein the coupling capacitance is formed between an extension of said second gate electrode and an extension of said first gate electrode at a location away from the channel region.
Claim 4
Dependent Claim
30 words
A display panel according to claim 2, further comprising an insulator which enables the coupling capacitance to be achieved, said insulator being positioned between the first and second gate electrodes.
Claim 5
Dependent Claim
16 words
A display panel according to claim 2, wherein said channel region is composed of amorphous silicon.
Claim 6
Dependent Claim
16 words
A display panel according to claim 1, wherein said channel region is composed of amorphous silicon.
Claim 7
Dependent Claim
30 words
A display panel according to claim 1, further comprising an insulator which enables the coupling capacitance to be achieved, said insulator being positioned between the first and second gate electrodes.
Claim 8
Dependent Claim
14 words
A display panel according to claim 1, wherein said substrate is a semiconductor substrate.
Claim 9
Dependent Claim
14 words
A display panel according to claim 1, wherein said substrate is an insulating substrate.
Claim 10
Dependent Claim
30 words
A display panel according to claim 1, further comprising an insulator which enables the coupling capacitance to be achieved, the insulator being positioned between the first and second gate electrodes.
Claim 11
Dependent Claim
35 words
A display panel according to claim 9, wherein the second gate electrode is made of aluminum, and the insulator is made of an aluminum oxide formed by oxidation of aluminum of the second gate electrode.
Claim 12
Dependent Claim
16 words
A display panel according to claim 10, wherein the gate insulator is formed of silicon nitride.
Claim 13
Dependent Claim
29 words
A display panel according to claim 9, wherein the insulator which enables the coupling capacitance to be achieved is smaller in thickness than the thickness of the gate insulator.
Claim 14
Dependent Claim
39 words
A display panel according to claim 9, wherein the coupling capacitance between the first and second gate electrodes, through the insulator, is greater than a capacitance between the first gate electrode and the channel region, through the gate insulator.
Claim 15
Dependent Claim
27 words
A display panel according to claim 1, wherein the source and drain electrodes do not overlap the first gate electrode but do overlap the second gate electrode.
Claim 16
Dependent Claim
29 words
A display panel according to claim 14, wherein the second gate electrode is provided on the substrate and the first gate electrode is provided overlying the second gate electrode.
Claim 17
Dependent Claim
27 words
A display panel according to claim 1, wherein the second gate electrode is formed of aluminum and the first gate electrode is formed of doped amorphous silicon.
Claim 18
Dependent Claim
43 words
A display panel according to claim 16, further comprising an insulator which enables the coupling capacitance to be achieved, between the first and second gate electrodes, and wherein the insulator which enables the coupling capacitance to be achieved is formed of aluminum oxide.
Claim 19
Dependent Claim
140 words
A display panel comprising: a substrate, a plurality of thin-film transistors formed on the substrate, and a liquid crystal formed on the substrate, wherein each of said plurality of thin-film transistors includes: a gate electrode, a channel region consisting of a semiconductor layer, a gate insulator formed between the gate electrode and the semiconductor layer, a source electrode and a drain electrode formed on said semiconductor layer, and a gate signal line that applies signals to said gate electrode, wherein said gate electrode and said gate signal line are electrically insulated from each other, a coupling capacitance is provided between said gate electrode and said gate signal line at a location away from said channel region, and a signal is applied to the gate signal line, such that a voltage is applied to said gate electrode via said coupling capacitance.
Claim 20
Dependent Claim
140 words
A display panel comprising: a substrate, a plurality of thin-film transistors formed on the substrate, and a liquid crystal formed on the substrate, wherein each of said plurality of thin-film transistors includes: a gate electrode, a channel region consisting of a semiconductor layer, a gate insulator formed between the gate electrode and the semiconductor layer, a source electrode and a drain electrode formed on said semiconductor layer, and a gate signal line that applies signals to said gate electrode, wherein said gate electrode and said gate signal line are electrically insulated from each other, a coupling capacitance is provided between said gate electrode and said gate signal line at a location away from said channel region, and a signal is applied to the gate signal line, such that a voltage is applied to said gate electrode via said coupling capacitance.
Claim 21
Dependent Claim
23 words
A display panel according to claim 18, wherein said substrate is an insulating substrate, and said semiconductor layer is composed of amorphous silicon.
Claim 22
Dependent Claim
92 words
A display panel according to claim 18, wherein provision is further made of a plurality of video signal lines, said gate signal line is provided in a plural number, said plurality of video signal lines and the plural number of gate signal lines are arranged in the form of a matrix, a video signal is input to either the source electrode or the drain electrode, and a pixel electrode is electrically connected to the other one of either the source electrode is electrically connected to electrode, thereby to constitute the display panel.
Claim 23
Dependent Claim
41 words
A display panel according to claim 18, further comprising an insulator provided between the gate electrode and the gate signal line, so as to enable said coupling capacitance to be achieved, said insulator being comprised of Al 2 O 3 .
Claim 24
Dependent Claim
41 words
A display panel according to claim 18, further comprising an insulator provided between the gate electrode and the gate signal line, so as to enable said coupling capacitance to be achieved, said insulator being comprised of Ta 2 O 5 .
Claim 25
Dependent Claim
14 words
A display panel according to claim 20, wherein said substrate is a semiconductor substrate.
Claim 26
Dependent Claim
23 words
A display panel according to claim 20, wherein said substrate is an insulating substrate, and said semiconductor layer is composed of amorphous silicon.
Claim 27
Dependent Claim
41 words
A display panel according to claim 20, further comprising an insulator provided between the gate electrode and the gate signal line, so as to enable said coupling capacitance to be achieved, said insulator being comprised of Ta 2 O 5 .
Claim 28
Dependent Claim
14 words
A display panel according to claim 20, wherein said substrate is a semiconductor substrate.
Claim 29
Dependent Claim
41 words
A display panel according to claim 20, further comprising an insulator provided between the gate electrode and the gate signal line, so as to enable said coupling capacitance to be achieved, said insulator being comprised of Al 2 O 3 .
Claim 30
Dependent Claim
23 words
A display panel according to claim 1, wherein said second gate electrode forms part of a gate bus line of the display panel.
Claim 31
Dependent Claim
29 words
A display panel according to claim 1, further comprising transparent pixel electrodes, with each transparent pixel electrode being electrically connected to the drain electrode of a respective thin-film transistor.
Claim 32
Dependent Claim
16 words
A display panel according to claim 3, wherein said insulator is thinner than said gate insulator.
Claim 33
Dependent Claim
21 words
A display panel according to claim 1, wherein said gate insulator is between the first gate electrode and the channel region.
Claim 34
Dependent Claim
30 words
A display panel according to claim 31, further comprising an insulator which enables the coupling capacitance to be achieved, said insulator being positioned between the first and second gate electrodes.
Claim 35
Dependent Claim
16 words
A display panel according to claim 32, wherein said insulator is thinner than said gate insulator.
Claim 36
Dependent Claim
23 words
A display panel according to claim 32, wherein the gate insulator and the insulator respectively are comprised of silicon nitride and aluminum oxide.
Claim 37
Dependent Claim
28 words
A display panel according to claim 1, wherein the source and drain electrodes overlap with the second gate electrode, but do not overlap with the first gate electrode.
References Cited (Backward Citations)
US4984041A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-29 | 1997-05-31 | 1997-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-29 | 2001-05-31 | 2001-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-29 | 2005-05-31 | 2005-11-30 | $7700.00 | Window Closed / Lapsed |