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US5448385A Expired / Lapsed US ⏱️ 0.0 years remaining

Active matrix liquid crystal display device with interdigitated counter electrodes

Assignee: Sagem SA
•
Filing: 1993-07-01
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Granted: 1995-09-05
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Expires: 2013-07-01
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Abstract

Abstract The device comprises a thin layer (10) of liquid crystals disposed between a plane backing electrode and control electrodes each co-operating with the backing electrode to define a capacitor and a picture element such that each pixel corresponds to a row and to a column, each control electrode being connected to a control element such as a thin-film transistor enabling it either to be raised to the potential of a conductor which is common to all of the pixels in the column to which it belongs, or else to isolate it therefrom and cause it to take up a floating potential. The backing electrode is made up of two fractions (20 1 , 20 2 ) provided with means enabling, them to be taken to different potentials that are inverted on each frame or multiple of the frame frequency, and in which successive columns (or successive groups of a few columns each) of control-electrodes co-operate with different ones of the fractions.

Inventors

  • 👤 Christophe Deffontaines
  • 👤 Ambroise Parker
  • 👤 Philippe Tison

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 03:38
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3648; G09G3/3655; G09G3/3614

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 173 words
A display device having an "active matrix" liquid crystal screen comprising a thin layer (10) of liquid crystals disposed between a plane backing electrode and control electrodes each co-operating with the backing electrode to define a capacitor and a picture element such that each pixel corresponds to a row and to a column, each control electrode being connected to a control element such as a thin-film transistor enabling it either to be raised to the potential of a conductor which is common to all of the pixels in the column to which it belongs, or else to isolate it therefrom and cause it to take up a floating potential, characterized in that the backing electrode is made up of two fractions (20 1 , 20 2 ) provided with means enabling, them to be taken to different potentials that are inverted on each frame or multiple of the frame frequency, and in which successive columns (or successive groups of a few columns each) of control electrodes co-operate with different ones of the fractions.
Claim 2
Dependent Claim 173 words
A display device having an "active matrix" liquid crystal screen comprising a thin layer (10) of liquid crystals disposed between a plane backing electrode and control electrodes each co-operating with the backing electrode to define a capacitor and a picture element such that each pixel corresponds to a row and to a column, each control electrode being connected to a control element such as a thin-film transistor enabling it either to be raised to the potential of a conductor which is common to all of the pixels in the column to which it belongs, or else to isolate it therefrom and cause it to take up a floating potential, characterized in that the backing electrode is made up of two fractions (20 1 , 20 2 ) provided with means enabling, them to be taken to different potentials that are inverted on each frame or multiple of the frame frequency, and in which successive columns (or successive groups of a few columns each) of control electrodes co-operate with different ones of the fractions.
Claim 3
Dependent Claim 33 words
A device according to claim 1, characterized in that the fractions are constituted by equipotential planes of interdigitated conductors, with fingers of a width corresponding to the width of a column of pixels.
Claim 4
Dependent Claim 18 words
A device according to claim 1, characterized in that the various potentials are equal and of opposite polarities.

References Cited (Backward Citations)

US4973135A Cited
FR2590394A1 Cited
EP0224388A2 Cited
JPH02116892A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-09-04 1999-03-06 1999-09-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-09-04 2003-03-06 2003-09-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-09-04 2007-03-06 2007-09-05 $7700.00 Window Closed / Lapsed

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