US4382658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of polysilicon for smoothing of liquid crystal MOS displays
Assignee: Raytheon Co
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Filing: 1980-11-24
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Granted: 1983-05-10
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Expires: 2000-11-24
Abstract
Abstract In a liquid crystal imaging display comprising a liquid crystal layer formed over the top surface of a MOS integrated circuit, the reflectivity of the pixel control electrodes is enhanced by means of a polycrystalline silicon layer formed over the MOS integrated circuit and polished to have an optically smooth surface over which the pixel control electrodes and the liquid crystal may be placed. Contrast ratios on the order of 100 to 1 are achieved.
Inventors
- 👤 Steven E. Shields
- 👤 Bruce G. Fletcher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:57
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/136; G02F1/1362; G02F1/136277; G02F2201/00; G02F2201/12; G02F2201/123; G02F2203/00; G02F2203/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
88 words
A liquid crystal display comprising: a semiconductor integrated circuit formed on a semiconductor substrate and having a top surface; a polycrystalline silicon layer formed over the top surface of said integrated circuit and divided into islands, said polycrystalline silicon layer having a top surface which is flatter than the top surface of said integrated circuit; a plurality of reflective pixel control electrodes each formed over the top surface of an individual one of said polycrystalline silicon islands; and a liquid crystal layer formed over said pixel control electrodes.
Claim 2
Dependent Claim
88 words
A liquid crystal display comprising: a semiconductor integrated circuit formed on a semiconductor substrate and having a top surface; a polycrystalline silicon layer formed over the top surface of said integrated circuit and divided into islands, said polycrystalline silicon layer having a top surface which is flatter than the top surface of said integrated circuit; a plurality of reflective pixel control electrodes each formed over the top surface of an individual one of said polycrystalline silicon islands; and a liquid crystal layer formed over said pixel control electrodes.
Claim 3
Dependent Claim
21 words
The display of claim 1 wherein said plurality of pixel control electrodes are individually connected to elements of said integrated circuit.
Claim 4
Dependent Claim
33 words
The display of claim 1 further comprising insulating material surrounding each of said polycrystalline silicon islands, including contact hole means providing connection between said pixel control electrodes and elements of said integrated circuits.
Claim 5
Dependent Claim
50 words
The display of claim 1 wherein an element of said integrated circuit comprises a source, a drain and a channel in said substrate, an overlying gate electrode and a capacitor electrode connected to one of said source and drain, said capacitor electrode connected to one of said pixel control electrodes.
Claim 6
Dependent Claim
27 words
The display of claims 2, 3 or 4 wherein connection to each of said pixel control electrodes is made through contact openings in said polycrystalline silicon layer.
Claim 7
Dependent Claim
32 words
The display of claims 2, 3 or 4 wherein connection to each of said pixel control electrodes is made through said polycrystalline silicon layer by dopant impurities in said polycrystalline silicon layer.
Claim 8
Dependent Claim
39 words
The display of claim 4 wherein connection between said capacitor electrode and said one pixel control electrode is made by dopant impurities located at least in a region in said polycrystalline silicon layer which directly contacts said capacitor electrode.
Claim 9
Dependent Claim
12 words
The display of claim 7 wherein said dopant impurities are ion implanted.
Claim 10
Dependent Claim
29 words
The device of claim 3 wherein said insulating material has a sufficient thickness to substantially prevent light generated carriers in each of said silicon islands leaving said silicon islands.
Claim 11
Dependent Claim
12 words
The display of claim 1 wherein said polycrystalline silicon layer is undoped.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-09 | 1986-11-08 | 1987-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-09 | 1990-11-08 | 1991-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-09 | 1994-11-08 | 1995-05-10 | $7700.00 | Window Closed / Lapsed |