US5016982A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal display having a capacitor for overvoltage protection
Assignee: Raychem Corp
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Filing: 1989-11-17
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Granted: 1991-05-21
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Expires: 2009-11-17
Abstract
Abstract A liquid crystal display (LCD) is connected in series with a capacitor having a capacitance C 0 such that C.sub.1 <C.sub.0 <C.sub.2 where C 1 is the capacitance of the LCD at its threshold voltage and C 2 is the capacitance of the LCD at its saturation voltage.
Inventors
- 👤 James L. Fergason
- 👤 Manoochehr Mohebban
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:27
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/13306; G02F1/1333; G02F1/1343; G02F1/134309; G02F1/1334; G02F1/137; G02F1/139; G02F1/1396
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
58 words
An electrical apparatus comprising (a) a liquid crystal display comprising a positive dielectric anisotropy liquid crystal and having a capacitance C 1 below its threshold voltage and a capacitance C 2 above its saturation voltage and (b) a capacitor connected in series with said display and having a substantially constant capacitance C 0 satisfying the inequality C.sub.0 <C.sub.2.
Claim 2
Dependent Claim
58 words
An electrical apparatus comprising (a) a liquid crystal display comprising a positive dielectric anisotropy liquid crystal and having a capacitance C 1 below its threshold voltage and a capacitance C 2 above its saturation voltage and (b) a capacitor connected in series with said display and having a substantially constant capacitance C 0 satisfying the inequality C.sub.0 <C.sub.2.
Claim 3
Dependent Claim
10 words
An apparatus according to claim 1 wherein C.sub.1 <C.sub.0 <C.sub.2.
Claim 4
Dependent Claim
20 words
An apparatus according to claim 1 or 2 wherein said positive dielectric anisotropy liquid crystal is encapsulated nematic liquid crystal.
Claim 5
Dependent Claim
86 words
An electrical apparatus comprising (a) a series-connected array of liquid crystal displays, each of said displays comprising a positive dielectric anisotropy liquid crystal and each of said displays having a capacitance C 1 below its threshold voltage and a capacitance C 2 above its saturation voltage, and (b) a capacitor connected in series with a display at a terminus of said array and having a substantially constant capacitance C 0 satisfying the inequality C.sub.0 <C.sub.2 /n, where n is the number of displays in said array.
Claim 6
Dependent Claim
86 words
An electrical apparatus comprising (a) a series-connected array of liquid crystal displays, each of said displays comprising a positive dielectric anisotropy liquid crystal and each of said displays having a capacitance C 1 below its threshold voltage and a capacitance C 2 above its saturation voltage, and (b) a capacitor connected in series with a display at a terminus of said array and having a substantially constant capacitance C 0 satisfying the inequality C.sub.0 <C.sub.2 /n, where n is the number of displays in said array.
Claim 7
Dependent Claim
18 words
An apparatus according to claim 4, wherein said positive dielectric anisotropy liquid crystal is encapsulated nematic liquid crystal.
Claim 8
Dependent Claim
80 words
An electrical circuit comprising: (a) a liquid crystal display comprising a positive dielectric anisotropy liquid crystal and having a capacitance C 1 below its threshold voltage and a capacitance C 2 above its threshold voltage; (b) a capacitor in series with said display, said capacitor having a substantially constant capacitance less than C 2 ; and (c) a means for applying a voltage less than the withstand voltage of said display across the combination of said display and said capacitor.
Claim 9
Dependent Claim
80 words
An electrical circuit comprising: (a) a liquid crystal display comprising a positive dielectric anisotropy liquid crystal and having a capacitance C 1 below its threshold voltage and a capacitance C 2 above its threshold voltage; (b) a capacitor in series with said display, said capacitor having a substantially constant capacitance less than C 2 ; and (c) a means for applying a voltage less than the withstand voltage of said display across the combination of said display and said capacitor.
Claim 10
Dependent Claim
20 words
A circuit in accordance with claim 6 wherein said substantially constant capacitance is between C 1 and C 2 .
Claim 11
Dependent Claim
16 words
A circuit in accordance with claim 6, further comprising at least one additional liquid crystal display.
Claim 12
Dependent Claim
25 words
A circuit in accordance with claim 8, wherein said at least one additional liquid crystal display is connected in series with said liquid crystal display.
Claim 13
Dependent Claim
26 words
A circuit in accordance with claim 6 wherein said means comprises a power supply having an output voltage less than the withstand voltage of said display.
Claim 14
Dependent Claim
33 words
A circuit in accordance with claim 6 wherein said means comprises (i) a power supply having an output voltage greater than the withstand voltage of said display and (ii) a voltage reduction means.
Claim 15
Dependent Claim
22 words
A circuit in accordance with claim 11 wherein said voltage reduction means comprises a capacitor connected in series with said power supply.
References Cited (Backward Citations)
US2969481A
Cited
US3725899A
Cited
US3979743A
Cited
US3889158A
Cited
US4040720A
Cited
US4290061A
Cited
DE2949561A1
Cited
US4405918A
Cited
US4456939A
Cited
US4523189A
Cited
US4435047A
Cited
US4529968A
Cited
US4580063A
Cited
DE3308972A1
Cited
DE3219703A1
Cited
DE3403655A1
Cited
US4639087A
Cited
US4643528A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-20 | 1994-11-19 | 1995-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-20 | 1998-11-19 | 1999-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-20 | 2002-11-19 | 2003-05-21 | $7700.00 | Window Closed / Lapsed |