← Back to Patent Explorer
US4728175A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid crystal display having pixels with auxiliary capacitance

Assignee: Guardian Industries Corp
•
Filing: 1986-10-09
•
Granted: 1988-03-01
•
Expires: 2006-10-09
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A light influencing display including at least one pixel having a pixel capacitance and an auxiliary capacitance in parallel with the pixel capacitance is disclosed. The pixel includes electrodes located in at least three spaced apart layers, namely a first electrode including first and second spaced apart electrode portions in a first layer, and a second electrode spaced from and facing the first electrode portions in substantially parallel relations thereto in a second layer. The second electrode is electrically insulated from all external circuit connections and from all other pixel electrodes and liquid crystal display material is disposed between the first electrode and the second electrode. The auxiliary capacitance is provided by at least a first auxiliary electrode in a third layer spaced and insulated from and facing at least the first electrode portion of the first electrode on the side of the first electrode opposite the liquid crystal material. The auxiliary electrode is electrically connected to the second electrode portion of the first electrode. Additional auxiliary capacitance can be provided by including in the pixel a second auxiliary electrode in the third layer connected to the first portion of the first electrode. A method of efficiently constructing such pixels using only one layer of insulation which performs three distinct functions is also disclosed. Further additional auxiliary capacitance may also be provided by including additional auxiliary electrodes located in additional layers.

Inventors

  • 👤 Yair Baron

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 23:08
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1345; G02F1/136; G02F1/1362; G02F1/136213; G02F1/1365; G02F1/1368

Claims Analysis

Total Claims: 33
Claim 1
Independent Claim 95 words
A light influencing display including at least one pixel having a pixel capacitance and an auxiliary capacitance, said pixel comprising: a first electrode including at least two spaced apart electrode portions; a second electrode spaced from and facing said first electrode portions in substantially parallel relation thereto, said second electrode also being electrically insulated from all external circuit connections and from all other pixel electrodes, said first and second electrodes being arranged to allow light influencing display material to be placed therebetween; and means, electrically connected to said first electrode for providing said auxiliary capacitance.
Claim 2
Dependent Claim 95 words
A light influencing display including at least one pixel having a pixel capacitance and an auxiliary capacitance, said pixel comprising: a first electrode including at least two spaced apart electrode portions; a second electrode spaced from and facing said first electrode portions in substantially parallel relation thereto, said second electrode also being electrically insulated from all external circuit connections and from all other pixel electrodes, said first and second electrodes being arranged to allow light influencing display material to be placed therebetween; and means, electrically connected to said first electrode for providing said auxiliary capacitance.
Claim 3
Dependent Claim 53 words
The display as in claim 1 wherein said means includes: a third electrode spaced and insulated from and facing at least one of said first electrode portions on the side of said first electrode opposite said second electrode, said third electrode also being electrically connected to another one of said first electrode portions.
Claim 4
Dependent Claim 25 words
The display as in claim 2 wherein said one first electrode portion and said another one of said electrode portions are immediately adjacent each other.
Claim 5
Dependent Claim 36 words
The display as in claim 3 wherein the surface area of said third electrode contributing to said auxiliary capacitance is substantially coextensive with substantially all of the active surface area of said one first electrode portion.
Claim 6
Dependent Claim 16 words
The display as defined in claim 2 wherein said third electrode is formed from a metal.
Claim 7
Dependent Claim 15 words
The display as defined in claim 5 wherein said metal is aluminum, chromium or molybdenum.
Claim 8
Dependent Claim 18 words
The display as defined in claim 2 wherein said third electrode is formed from a transparent conductive material.
Claim 9
Dependent Claim 21 words
The display as in claim 2 further including at least one isolation device coupled to one of said first electrode portions.
Claim 10
Dependent Claim 27 words
The display as in claim 8 wherein said one isolation device is coupled to said at least one of said first electrode portions through said third electrode.
Claim 11
Dependent Claim 20 words
The display as in claim 8 including at least one isolation device coupled to each of said first electrode portions.
Claim 12
Dependent Claim 25 words
The display as in claim 2 further including at least a pair of isolation devices coupled to at least one of said first electrode portions.
Claim 13
Dependent Claim 29 words
The display as in claim 11 wherein one of said isolation devices of said pair of isolation devices is coupled to said first electrode portion through said third electrode.
Claim 14
Dependent Claim 20 words
The display as in claim 11 including a pair of isolation devices coupled to each of said first electrode portions.
Claim 15
Dependent Claim 23 words
The display as in claim 11 wherein said isolation devices are diodes formed at least in part from thin film non-single-crystal semiconductor material.
Claim 16
Dependent Claim 26 words
The display as defined in claim 2 including said light influencing material placed between said first and second electrodes in the form of liquid crystal material.
Claim 17
Dependent Claim 15 words
The display as in claim 15 wherein said liquid crystal material is twisted nematic material.
Claim 18
Dependent Claim 51 words
The display as in claim 2 wherein said means further includes a fourth electrode spaced and insulated from and facing said another one of said first electrode portions on the side of said first electrode opposite said second electrode, said fourth electrode being electrically connected to said one first electrode portion.
Claim 19
Dependent Claim 39 words
The display as in claim 17 wherein the surface area of said fourth electrode contributing to said auxiliary capacitance is substantially coextensive with substantially all of the active surface area of said another one of said first electrode portions.
Claim 20
Dependent Claim 52 words
The display as in claim 17 further including a pair of isolation devices coupled to each of said two first electrode portions, and wherein at least one isolation device of each said pair of isolation devices is coupled to its respective first electrode portion through one of said third or fourth electrodes.
Claim 21
Dependent Claim 48 words
The display as in claim 17 wherein said means further includes a fifth electrode spaced and insulated from and facing said third electrode on the side of said third electrode opposite said one first electrode portion, said fifth electrode being electrically connected to said one first electrode portion.
Claim 22
Dependent Claim 48 words
The display as in claim 20 wherein said means further includes a sixth electrode spaced and insulated from and facing said fourth electrode on the side of said fourth electrode opposite said another first electrode portion, said sixth electrode being electrically connected to said another first electrode portion.
Claim 23
Dependent Claim 87 words
The display as in claim 17 wherein said third and fourth electrodes are substantially coplanar, and said display further includes a fifth electrode spaced and insulated from and facing said third electrode on the side of said third electrode opposite said one first electrode portion and at least one conductive pad physically separated from and substantially coplanar with said third and fourth electrodes, said fifth electrode being electrically connected to said one electrode portion through said conductive pad and also being electrically connected to said fourth electrode.
Claim 24
Dependent Claim 46 words
The display as in claim 2 wherein said means further includes a fourth electrode spaced and insulated from and facing said third electrode on the side of said third electrode opposite said first electrode, said fourth electrode being electrically connected to said one first electrode portion.
Claim 25
Dependent Claim 24 words
The display as in claim 23 wherein said third electrode is also spaced from and faces said another one of said first electrode portions.
Claim 26
Dependent Claim 41 words
The display as in claim 23 further including a fifth electrode spaced and insulated from and facing said fourth electrode on the side of said fourth electrode opposite said third electrode, said fifth electrode being electrically connected to said third electrode.
Claim 27
Independent Claim 215 words
A method for constructing a pixel in a light influencing display having a plurality of pixels comprising the steps of: (a) forming above a substrate a first conductor for providing current to said pixel and to at least one other pixel of said display, at least a first auxiliary capacitance electrode for said pixel, and at least one isolation device associated with said pixel; (b) providing a layer of insulating material which extends over substantial portions of said conductor and substantial portions of said electrode and which substantially protects and isolates said isolation device from unintended contact with other conductors in said display; and (c) providing on top of said layer at least a portion of a second conductor for providing current to said pixel and to at least one other pixel of said display arranged so as to cross said first conductor, and a first portion of a pixel electrode disposed at least in part above said first auxiliary electrode for forming a first auxiliary pixel capacitance therewith, whereby said layer of insulating material performs at least three distinct functions, namely insulating said first and second conductors from one another at the location where they cross, acting as the dielectric material of said auxiliary pixel capacitance, and substantially protecting and isolating said isolation device.
Claim 28
Independent Claim 215 words
A method for constructing a pixel in a light influencing display having a plurality of pixels comprising the steps of: (a) forming above a substrate a first conductor for providing current to said pixel and to at least one other pixel of said display, at least a first auxiliary capacitance electrode for said pixel, and at least one isolation device associated with said pixel; (b) providing a layer of insulating material which extends over substantial portions of said conductor and substantial portions of said electrode and which substantially protects and isolates said isolation device from unintended contact with other conductors in said display; and (c) providing on top of said layer at least a portion of a second conductor for providing current to said pixel and to at least one other pixel of said display arranged so as to cross said first conductor, and a first portion of a pixel electrode disposed at least in part above said first auxiliary electrode for forming a first auxiliary pixel capacitance therewith, whereby said layer of insulating material performs at least three distinct functions, namely insulating said first and second conductors from one another at the location where they cross, acting as the dielectric material of said auxiliary pixel capacitance, and substantially protecting and isolating said isolation device.
Claim 29
Dependent Claim 19 words
A method as in claim 26 wherein said conductors are address lines orthogonally arranged with respect to one another.
Claim 30
Dependent Claim 22 words
A method as in claim 27 wherein said second conductor is formed substantially entirely on top of said layer of insulating material.
Claim 31
Dependent Claim 55 words
A method as in claim 26 further comprising the steps of: (d) providing an opening in said layer of insulating material above said isolation device; and (e) providing a conductive interconnect disposed at least in part above said layer electrically connecting the isolation device through said opening to said first portion of said pixel electrode.
Claim 32
Dependent Claim 84 words
A method as in claim 26 further comprising the steps of: (d) providing a second auxiliary capacitance electrode in the same general plane as and horizontally separated and electrically isolated from said first auxiliary capacitance electrode; and (e) providing on top of said layer a second portion of said pixel electrode disposed in substantial part above said second auxiliary electrode for forming a second auxiliary pixel capacitance, whereby said layer of insulating material acts as the dielectric material for said second auxiliary pixel capacitance.
Claim 33
Dependent Claim 71 words
A method as in claim 30 further comprising the step of: (f) providing first and second openings in said layer of insulating material respectively above said first and second auxiliary capacitance electrodes; (g) electrically connecting said first auxiliary electrode through said first opening to said second portion of said pixel electrode; and (h) electrically connecting said second auxiliary electrode through said second opening to said second portion of said pixel electrode.

References Cited (Backward Citations)

US4523811A Cited
US4534623A Cited
US4589733A Cited
US4639087A Cited
US4676603A Cited
US4697331A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-03-01 1991-08-31 1992-03-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-03-01 1995-08-31 1996-03-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-03-01 1999-08-31 2000-03-01 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag