US4810060A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active color liquid crystal display element compensating for differing voltage-transmission curves of the primary colors
Assignee: TPO Hong Kong Holding Ltd
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Filing: 1988-01-14
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Granted: 1989-03-07
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Expires: 2008-01-14
Abstract
Abstract In an active color liquid crystal display element in which display electrodes are arranged in a matrix form within a liquid crystal cell, color filters of three primary colors are each disposed opposite one of the display electrodes, the color filters of the three colors being distributed substantially uniformly, and a thin film transistor connected to each display electrode is controlled, by switching, in accordance with an input color image signal to charge and discharge the display electrode for displaying a color image, the structures of the thin film transistors are selected corresponding to the color filters of the three primary colors so that substantially the same light transmission-voltage characteristic is provided for all the three color filter portions.
Inventors
- 👤 Yasuhiro Ukai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:47
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/136; G02F1/1362; G02F1/1368; G02F1/1333; G02F1/1335; G02F1/133509; G02F1/133514
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
122 words
An active color liquid crystal display element in which display electrodes are arranged in a matrix form within a liquid crystal cell, color filters of three primary colors are each disposed opposite one of the display electrodes, the color filters being distributed substantially uniformly, and a thin film transistor connected to each display electrode is controlled, by switching, in accordance with an input color image signal, whereby charging and discharging of the display electrode are selectively performed to thereby display a color image, characterized in that the structures of the thin film transistors are selected corresponding to the color filters of the three primary colors so that substantially the same light transmission-voltage characteristic is provided for all the three color filter portions.
Claim 2
Dependent Claim
122 words
An active color liquid crystal display element in which display electrodes are arranged in a matrix form within a liquid crystal cell, color filters of three primary colors are each disposed opposite one of the display electrodes, the color filters being distributed substantially uniformly, and a thin film transistor connected to each display electrode is controlled, by switching, in accordance with an input color image signal, whereby charging and discharging of the display electrode are selectively performed to thereby display a color image, characterized in that the structures of the thin film transistors are selected corresponding to the color filters of the three primary colors so that substantially the same light transmission-voltage characteristic is provided for all the three color filter portions.
Claim 3
Dependent Claim
30 words
The color liquid crystal display element of claim 1, wherein the configuration of the channel of each thin film transistor is selected in accordance with the color filter corresponding thereto.
Claim 4
Dependent Claim
85 words
The color liquid crystal display element of claim 2, wherein, letting the width and length of the channel be represented by W and L, respectively, a ratio W/L of the thin film transistor connected to the display electrode of the green color filter is higher than the ratio W/L of the thin film transistor connected to the display electrode of the red color filter but lower than the ratio W/L of the thin film transistor connected to the display electrode of the blue color filter.
Claim 5
Dependent Claim
32 words
The color liquid crystal display element of claim 1, wherein the thickness of a gate insulating film of each thin film transistor is selected in accordance with the color filter corresponding thereto.
Claim 6
Dependent Claim
73 words
The color liquid crystal display element of claim 4, wherein the gate insulating film of the thin film transistor connected to the display electrode of the green color filter is thinner than the gate insulating film of the thin film transistor connected to the display electrode of the red color filter but thicker than the gate insulating film of the thin film transistor connected to the display electrode of the blue color filter.
Claim 7
Dependent Claim
32 words
The color liquid crystal display element of claim 1, wherein the impurity concentration of a semiconductor layer of each thin film transistor is selected in accordance with the color filter corresponding thereto.
Claim 8
Dependent Claim
82 words
The color liquid crystal display element of claim 6, wherein the impurity concentration of the semiconductor layer of the thin film transistor connected to the display electrode of the green color filter is higher than the impurity concentration of the semiconductor layer of the thin film transistor connected to the display electrode of the red color filter but lower than the impurity concentration of the semiconductor layer of the thin film transistor connected to the display electrode of the blue color filter.
Claim 9
Dependent Claim
28 words
The color liquid crystal display element of claim 1, wherein the storage capacitance of each thin film transistor is selected in accordance with the color filter corresponding thereto.
Claim 10
Dependent Claim
70 words
The color liquid crystal display element of claim 8, wherein an auxiliary capacitor is connected in parallel to the display electrode of the green color filter to provide an increased storage capacitance for the thin film transistor corresponding thereto, and an auxiliary capacitor is connected in parallel to the display electrode of the red color filter to provide a further increased storage capacitance for the thin film transistor corresponding thereto.
Claim 11
Dependent Claim
30 words
The color liquid crystal display element of claim 9, wherein the auxiliary capacitors are each formed by an auxiliary electrode of a transparent conductive film disposed opposite each display electrode.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-06 | 1992-09-05 | 1993-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-06 | 1996-09-05 | 1997-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-06 | 2000-09-05 | 2001-03-07 | $7700.00 | Window Closed / Lapsed |