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US4490014A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid crystal display with low capacitance zinc oxide varistor

Assignee: General Electric Co
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Filing: 1981-02-11
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Granted: 1984-12-25
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Expires: 2001-02-11
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Abstract

Abstract A highly multiplexed liquid crystal display employs nonlinear varistor elements exhibiting a particularly low capacitance value to effectively drive individual liquid crystal cells. Low varistor capacitance is achieved through controlled addition of Sb 2 O 3 during varistor manufacture.

Inventors

  • 👤 Lionel M. Levinson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 14:08
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/136; G02F1/1362; G02F1/1365

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 237 words
In a multiplexible matrix display including a plurality, N, of elongated, non-intersecting column electrodes and an N×M array of reflective display electrodes arranged behind and in registration with said column electrodes and further including a layer of optically active material display electrodes, said optically active material having a light transmissivity dependent on the voltage between said column and said display electrodes, each of said display electrodes being adjacent and connected to a first portion of a slab of nonlinear zinc oxide based varistor material comprising zinc oxide grains separated by layers of insulating intergranular material, a second portion of said slab having disposed thereon in electrical contact therewith M elongated, non-intersecting row electrodes extending in a direction substantially transverse to said column electrodes and further being in registration with said display electrodes, said varistor material exhibiting a dielectric constant ε and a breakdown field, F 1 ; the improvement in which: said varistor material consists of between 2 mole percent and 8 mole percent Sb 2 O 3 , a quantity of Bi 2 O 3 selected so that the mole percentage of Sb 2 O 3 is more than twice the mole percentage of Bi 2 O 3 , at least one other material selected from the group consisting of Co 2 O 3 , MnO 2 , NiO, Cr 2 O 3 , BaCO 3 and H 3 BO 3 and the balance being ZnO.
Claim 2
Dependent Claim 237 words
In a multiplexible matrix display including a plurality, N, of elongated, non-intersecting column electrodes and an N×M array of reflective display electrodes arranged behind and in registration with said column electrodes and further including a layer of optically active material display electrodes, said optically active material having a light transmissivity dependent on the voltage between said column and said display electrodes, each of said display electrodes being adjacent and connected to a first portion of a slab of nonlinear zinc oxide based varistor material comprising zinc oxide grains separated by layers of insulating intergranular material, a second portion of said slab having disposed thereon in electrical contact therewith M elongated, non-intersecting row electrodes extending in a direction substantially transverse to said column electrodes and further being in registration with said display electrodes, said varistor material exhibiting a dielectric constant ε and a breakdown field, F 1 ; the improvement in which: said varistor material consists of between 2 mole percent and 8 mole percent Sb 2 O 3 , a quantity of Bi 2 O 3 selected so that the mole percentage of Sb 2 O 3 is more than twice the mole percentage of Bi 2 O 3 , at least one other material selected from the group consisting of Co 2 O 3 , MnO 2 , NiO, Cr 2 O 3 , BaCO 3 and H 3 BO 3 and the balance being ZnO.
Claim 3
Dependent Claim 17 words
The matrix display of claim 1 wherein the product εF 1 is at most 1.14×10 +6 volts/cm.
Claim 4
Dependent Claim 26 words
The matrix display of claim 1 wherein said varistor material comprises Sb 2 O 3 and Bi 2 O 3 in a 4:1 mole percent ratio.
Claim 5
Dependent Claim 38 words
The matrix display of claim 1 wherein the mole percentage of each of said materials other than Sb 2 O 3 and ZnO is less than 2 mole percent of the total molar percentage of said varistor material.
Claim 6
Dependent Claim 78 words
The matrix display of claim 1 in which said varistor slab comprises approximately 0.5 mole percent Bi 2 O 3 , 0.5 mole percent Co 2 O 3 , 0.5 mole percent MnO 2 , 1 mole percent NiO, 0.5 mole percent Cr 2 O 3 , 0.1 mole percent BaCO 3 , 0.2 mole percent H 3 BO 3 , between 2 mole percent and 8 mole percent Sb 2 O 3 , the balance being ZnO.
Claim 7
Dependent Claim 265 words
In a multiplexible matrix display including a plurality, N, of elongated, non-intersecting column electrodes and an N×M array of reflective display electrodes arranged behind and in registration with said column electrodes and further including a layer of optically active mterial disposed between said column electrodes and said display electrodes, said optically active material having a light transmissivity dependent on the voltage between said column and said display electrodes, said optically active material having a light transmissivity dependent on the voltage between said column and said display electrodes, each of said display electrodes being adjacent and connected to a first portion of a slab of nonlinear zinc oxide based varistor material comprising zinc oxide grains separated by layers of insulating intergranular material, a second portion of said slab having disposed thereon in electrical contact therewith M elongated, non-intersecting row electrodes extending in a direction substantially transverse to said column electrodes and further being in registration with said display electrodes, said varistor material exhibiting a dielectric constant ε and a breakdown field, F 1 ; the improvement in which: said varistor material consisting of between 2 mole percent and 8 mole percent Sb 2 O 3 , a quantity of Bi 2 O 3 selected so that the mole percentage of Sb 2 O 3 is more than twice the mole percentage of Bi 2 O 3 , at least one other material selected from the group consisting of Co 2 O 3 , MnO 2 , NiO, Cr 2 O 3 , BaCO 3 and H 3 BO 3 and at least 88.7 mole percent ZnO.
Claim 8
Dependent Claim 265 words
In a multiplexible matrix display including a plurality, N, of elongated, non-intersecting column electrodes and an N×M array of reflective display electrodes arranged behind and in registration with said column electrodes and further including a layer of optically active mterial disposed between said column electrodes and said display electrodes, said optically active material having a light transmissivity dependent on the voltage between said column and said display electrodes, said optically active material having a light transmissivity dependent on the voltage between said column and said display electrodes, each of said display electrodes being adjacent and connected to a first portion of a slab of nonlinear zinc oxide based varistor material comprising zinc oxide grains separated by layers of insulating intergranular material, a second portion of said slab having disposed thereon in electrical contact therewith M elongated, non-intersecting row electrodes extending in a direction substantially transverse to said column electrodes and further being in registration with said display electrodes, said varistor material exhibiting a dielectric constant ε and a breakdown field, F 1 ; the improvement in which: said varistor material consisting of between 2 mole percent and 8 mole percent Sb 2 O 3 , a quantity of Bi 2 O 3 selected so that the mole percentage of Sb 2 O 3 is more than twice the mole percentage of Bi 2 O 3 , at least one other material selected from the group consisting of Co 2 O 3 , MnO 2 , NiO, Cr 2 O 3 , BaCO 3 and H 3 BO 3 and at least 88.7 mole percent ZnO.
Claim 9
Dependent Claim 36 words
The matrix display of claim 6 in which the mole percentage of each of said metal oxides other than Sb 2 O 3 and ZnO is less than 2 mole percent of the total molar percentage.
Claim 10
Dependent Claim 26 words
The matrix display of claim 6 wherein said varistor material comprises Sb 2 O 3 and Bi 2 O 3 in a 4:1 mole percent ratio.
Claim 11
Dependent Claim 17 words
The matrix display of claim 6 wherein the product εF 1 is at most 1.14×10 +6 volts/cm.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-12-25 1988-06-25 1988-12-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-12-25 1992-06-25 1992-12-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-12-25 1996-06-25 1996-12-25 $7700.00 Window Closed / Lapsed

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