Patent EP0174431A1 successfully refreshed from Google Patents.
EP0174431A1
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EP
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Liquid crystal display devices and method for production thereof
Assignee: International Business Machines Corp
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Filing: 1985-04-30
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Granted: —
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Expires: 2005-04-30
Abstract
Abstract A matrix addressable liquid crystal display includes a thin film circuit suppported on a substrate 10 having a plurality of parallel bit lines 12. A plurality of individual pixel circuits each include a two terminals thin film bi-directional gate device 18 having one terminal connected to the associated bit line. A terminal plate 30 is connected in circuit with the other terminal of the gate device. A transparent cover plate 22 is spaced above the thin film circuit with a transparent conductor structure 24 on the underside of the cover plate. The structure 24 comprises a plurality of parallel word lines orthogonally to the bit lines. The space beneath the cover plate is filled with a liquid crystal display material 26 to form individual display elements at the respective cross-overs of the bit and word lines. The pixel circuits are each operable to change the state of the associated portion of the liquid crystal display material in response to the concurrent application of voltage pulses of opposite polarities to the associated word and bit lines.
Inventors
- 👤 Donelli Joseph Dimaria
- 👤 Hans Peter Wolf
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 16:57
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/136; G02F1/1362; G02F1/1365
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
253 words
A matrix addressable liquid crystal display comprising an insulating substrate (10), a thin film circuit supported on said substrate including a plurality of bit lines (12), generally arranged in parallel thereon, a plurality of individual pixel circuits each comprising a two terminal bi-directional gate device (18) formed from at least one thin film layer with one terminal of each gate device comprising at least a part of one surface of said gate device connected in circuit with the associated bit line (12) and with the other terminal comprising the other surface of said gate device (18), a terminal plate (30) connected in circuit with said other terminal of said gate device (18), a transparent cover plate (22) spaced above said thin film circuit, the space beneath said cover plate (22) and above said terminal plate (30) being filled with a liquid crystal display material (26) to form a part of each of said individual pixel circuits of said terminal plates, a substantially transparent conductor structure positioned and arranged on the underside of said cover plate including a plurality of parallel word lines (24) arranged orthogonally to, and insulated from, said bit lines (12), said word lines (24) being connected in circuit with said individual display pixel circuits at'he respective cross-overs with said bit lines, said pixel circuits each being operable to change the state of the associated portion of said liquid crystal display material in response to the concurrent application of voltage pulses of opposite polarities to the associated word and bit lines.
Claim 2
Dependent Claim
253 words
A matrix addressable liquid crystal display comprising an insulating substrate (10), a thin film circuit supported on said substrate including a plurality of bit lines (12), generally arranged in parallel thereon, a plurality of individual pixel circuits each comprising a two terminal bi-directional gate device (18) formed from at least one thin film layer with one terminal of each gate device comprising at least a part of one surface of said gate device connected in circuit with the associated bit line (12) and with the other terminal comprising the other surface of said gate device (18), a terminal plate (30) connected in circuit with said other terminal of said gate device (18), a transparent cover plate (22) spaced above said thin film circuit, the space beneath said cover plate (22) and above said terminal plate (30) being filled with a liquid crystal display material (26) to form a part of each of said individual pixel circuits of said terminal plates, a substantially transparent conductor structure positioned and arranged on the underside of said cover plate including a plurality of parallel word lines (24) arranged orthogonally to, and insulated from, said bit lines (12), said word lines (24) being connected in circuit with said individual display pixel circuits at'he respective cross-overs with said bit lines, said pixel circuits each being operable to change the state of the associated portion of said liquid crystal display material in response to the concurrent application of voltage pulses of opposite polarities to the associated word and bit lines.
Claim 3
Dependent Claim
252 words
A matrix addressable liquid crystal display comprising an insulating substrate (10), a thin film circuit supported on said substrate including a plurality of bit lines (12X) generally arranged in parallel thereon, a plurality of individual pixel circuits each comprising a two terminal bi-directional gate device (18X and 18X1) formed from at least one thin film layer with one terminal of each gate device comprising at least a part of one surface of said gate device connected in circuit with the associated bit line (12X) and with the other terminal comprising the other end surface of said gate device, a terminal plate (30X) connected in circuit with said other terminal of said gate device, a transparent cover plate (22X) spaced above said thin film circuit, a substantially transparent conductor structure (24Y) positioned and arranged on the underside of said cover plate, the space beneath said cover plate and above said terminal plate (30X) being filled with a liquid crystal display material to form a part of each of said individual pixel circuits at said terminal plates, a plurality of parallel word lines (24X) arranged orthogonally to, and insulated from, said bit lines (12X), said word lines being connected in circuit with said individual display pixel circuits at the respective cross-overs with said bit lines, said pixel circuit each being operable to change the state of the associated portion of said liquid crystal display material in response to the concurrent application of voltage pulses of opposite polarities to the associated word and bit lines.
Claim 4
Dependent Claim
252 words
A matrix addressable liquid crystal display comprising an insulating substrate (10), a thin film circuit supported on said substrate including a plurality of bit lines (12X) generally arranged in parallel thereon, a plurality of individual pixel circuits each comprising a two terminal bi-directional gate device (18X and 18X1) formed from at least one thin film layer with one terminal of each gate device comprising at least a part of one surface of said gate device connected in circuit with the associated bit line (12X) and with the other terminal comprising the other end surface of said gate device, a terminal plate (30X) connected in circuit with said other terminal of said gate device, a transparent cover plate (22X) spaced above said thin film circuit, a substantially transparent conductor structure (24Y) positioned and arranged on the underside of said cover plate, the space beneath said cover plate and above said terminal plate (30X) being filled with a liquid crystal display material to form a part of each of said individual pixel circuits at said terminal plates, a plurality of parallel word lines (24X) arranged orthogonally to, and insulated from, said bit lines (12X), said word lines being connected in circuit with said individual display pixel circuits at the respective cross-overs with said bit lines, said pixel circuit each being operable to change the state of the associated portion of said liquid crystal display material in response to the concurrent application of voltage pulses of opposite polarities to the associated word and bit lines.
Claim 5
Dependent Claim
31 words
A display as claimed in claim 1 or 2 wherein a respective thin film capacitor (42) is provided in series between each of said terminal plates and its associated word line.
Claim 6
Dependent Claim
44 words
A display as claimed in claim 1 or 2 wherein said two terminal bi-directional gate device comprises at least one thin film layer of a large band gap insulating material with microscopic agglomerated islands of a material therein which is at least a semiconductor.
Claim 7
Dependent Claim
54 words
A display as claimed in claim 4 wherein said large band gap insulating material is selected from the group consisting of silicon dioxide, silicon nitride, and aluminium oxide, and wherein the material which is at least a semiconductor is selected from the group consisting of silicon, gold, copper, nickel, tungsten, titanium, tantalum and aluminum.
Claim 8
Dependent Claim
31 words
A display device as claimed in claim 4 or 5 wherein said gate device layer consists essentially of silicon dioxide or silicon nitride with an excess of silicon forming said islands.
Claim 9
Dependent Claim
39 words
A display as claimed in claim 4 or 5 wherein said thin film layer of said gate device consists essentially of aluminium oxide and wherein said islands of material which is at least a semiconductor consist essentially of aluminium.
Claim 10
Dependent Claim
68 words
A display as claimed in claim 4 wherein said bi-directional gate device is formed of two thin film layers, said thin film layers each consisting of a large band gap insulating material consisting of silicon dioxide or silicon nitride with an excess of silicon forming said islands, and said gate device further including a thin film layer of silicon dioxide positioned between the aforesaid two thin film layers.
Claim 11
Dependent Claim
250 words
A matrix addressable liquid crystal display comprising an insulating substrate (10), a thin film circuit supported on said substrate including a plurality of bit lines (12) generally arranged in parallel thereon, an insulation material (14) arranged over said bit lines, individual window openings (16) arranged in a pattern in said insulation material over said bit lines, a two terminal bi-directional gate device (18) formed from at least one thin film layer in each of said windows with one terminal of each gate device comprising at least a part of the bottom area of said gate device in touch with the associated bit line and with the other terminal comprising at least a part of the top surface of said gate device and being exposed throught Said window, a transparent cover plate (28) spaced above said thin film circuit, substantially transparent word line conductors (24) positioned and arranged substantially in parallel on the underside of said cover plate and aligned at an angle to said bit lines and substantially in alignment with said windows, the space beneath said cover plate being filled with a liquid crystal display material (26) to form individual display pixel circuits at said windows controllable by a combination of voltages on said bit lines (12) and said word lines (24), each of said pixel circuits including the gate device formed in the associated windows in series with the liquid crystal display material positioned between said exposed gate terminal of said gate device and an associated word line.
Claim 12
Dependent Claim
250 words
A matrix addressable liquid crystal display comprising an insulating substrate (10), a thin film circuit supported on said substrate including a plurality of bit lines (12) generally arranged in parallel thereon, an insulation material (14) arranged over said bit lines, individual window openings (16) arranged in a pattern in said insulation material over said bit lines, a two terminal bi-directional gate device (18) formed from at least one thin film layer in each of said windows with one terminal of each gate device comprising at least a part of the bottom area of said gate device in touch with the associated bit line and with the other terminal comprising at least a part of the top surface of said gate device and being exposed throught Said window, a transparent cover plate (28) spaced above said thin film circuit, substantially transparent word line conductors (24) positioned and arranged substantially in parallel on the underside of said cover plate and aligned at an angle to said bit lines and substantially in alignment with said windows, the space beneath said cover plate being filled with a liquid crystal display material (26) to form individual display pixel circuits at said windows controllable by a combination of voltages on said bit lines (12) and said word lines (24), each of said pixel circuits including the gate device formed in the associated windows in series with the liquid crystal display material positioned between said exposed gate terminal of said gate device and an associated word line.
Claim 13
Dependent Claim
57 words
A display as claimed in claim 9 wherein said word line conductors are arranged substantially perpendicular to said bit lines, and wherein said bi-directional gate device includes an additional thin film layer of conductive material overlaying and in conductive relationship with said previously mentioned thin film layer and forming the top terminal plate of said gate device.
Claim 14
Dependent Claim
51 words
A display as claimed in claim 10 wherein said top terminal plate layer of said gate device is substantially larger than the area of said window and extends over said insulation material over the associated bit line, the top terminal plate layers for adjacent gate devices being insulated from one another.
Claim 15
Dependent Claim
23 words
A display as claimed in claim 10 or 11 wherein a layer of dielectric material is provided over said top terminal plate layer.
Claim 16
Dependent Claim
52 words
A display as claimed in claim 10, 11 or 12, wherein said bit lines are comprised of polycrystalline silicon material, said insulation material arranged over said bit lines is comprised of silicon dioxide, said top terminal plate layer consists essentially of polycrystalline silicon, and said dielectric layer consists essentially of silicon dioxide.
Claim 17
Independent Claim
172 words
A method of making a high density high resolution matrix addressable liquid crystal display comprising the steps of forming a thin film of a conductive material on a glass substrate, creating a pattern of parallel bit lines in said film by lithography and etching, oxiding said bit lines to provide an insulating cover for said lines, opening a pattern of small windows in the oxide insulation of said bit lines to form small windows to provide one such window for each desired liquid crystal display pixel cell, depositing at least one thin film layer of a material in said window which is effective to form a bi-directional gate device, depositing an upper conductive plate layer over said bi-drectional gate device to form an upper terminal for said gate device, forming parallel word lines on the underside of a glass cover plate, assembling said glass cover plate over the remainder of the structure and in spaced relation thereto, and filling the remaining space beneath said cover plate with a liquid crystal display material.
Claim 18
Independent Claim
172 words
A method of making a high density high resolution matrix addressable liquid crystal display comprising the steps of forming a thin film of a conductive material on a glass substrate, creating a pattern of parallel bit lines in said film by lithography and etching, oxiding said bit lines to provide an insulating cover for said lines, opening a pattern of small windows in the oxide insulation of said bit lines to form small windows to provide one such window for each desired liquid crystal display pixel cell, depositing at least one thin film layer of a material in said window which is effective to form a bi-directional gate device, depositing an upper conductive plate layer over said bi-drectional gate device to form an upper terminal for said gate device, forming parallel word lines on the underside of a glass cover plate, assembling said glass cover plate over the remainder of the structure and in spaced relation thereto, and filling the remaining space beneath said cover plate with a liquid crystal display material.
Claim 19
Dependent Claim
67 words
A method as claimed in claim 14 wherein the thin film of a conductive material on the glass substrate consists essentially of a doped polycrystalline silicon, and wherein said thin film layer of material deposited in said window to form a bi-directional gate device consists essentially of a large band gap insulating material with microscopic agglomerated islands of a material therein which is at least a semiconductor.
Claim 20
Dependent Claim
55 words
A method as claimed in claim 15 wherein said large band gap insulating material is selected from the group consisting of silicon dioxide, silicon nitride, and aluminium oxide, and wherein the material which is at least a semiconductor is selected from the group consisting of silicon, aluminium, gold, copper, nickel, tungsten, titanium, tantalum and aluminium.
Claim 21
Dependent Claim
57 words
A method as claimed in claim 16 wherein said thin film of a conductive material on the glass substrate consists essentially of doped polycrystalline silicon, and wherein said thin film layer forming said bi-directional gate device consists essentially of a silicon-rich silicon dioxide so that the material which is at least a semiconductor consists essentially of silicon.
References Cited (Backward Citations)
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