US 4,233,603 AGranted

Multiplexed varistor-controlled liquid crystal display

AssigneeGeneral Electric Company

InventorDonald E. Castleberry

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Abstract

Liquid crystal displays allowing high order multiplexing, typically with a multiplexing order N of about 1,000, utilize a thin sheet of a varistor material to provide a high degree of non-linearity in the optical response of the display with respect to the multiplexed driving voltage for each cell of the display.

Claims44

Dependent claims

A multiplexible matrix reflective display, comprising:

a plurality of substantially parallel and substantially transparent elongated and continuous column electrodes arranged spaced each from the others in a first direction in a first plane, each of said column electrodes adapted for having a column driving voltage coupled thereto;
a plurality of reflective and substantially flat coplanar rear cell electrodes arranged spaced each from the others in a matrix extending in both said first direction and in a second direction, substantially transverse to said first direction, in a second plane parallel to, and spaced behind, said first plane;
a plurality of substantially parallel row electrodes arranged spaced each from the others in said second direction and with only one of the row electrodes positioned substantially parallel to an associated row of said rear cell electrodes, each of said row electrodes adapted for having a row driving voltage coupled thereto;
a layer of optically active material positioned as the only element between said first and second planes, said layer having a matrix therein of cells each defined by the registration of one of said plurality of column electrodes and one of said plurality of rear cell electrodes;
the optically active material in each cell respectively absorbing therein and transmitting therethrough light entering said cell responsive to the magnitude of the voltage between the portions of the column and rear cell electrode defining said cell being respectively less than and at least equal to a preselected voltage magnitude;
a member of an electrically non-linear resistive material, positioned substantially parallel to the plane of at least said optically active layer and substantially covering the entire area of and in registration with said optically active layer, said member having a matrix of positions defined thereon with each position forming a passive, monotonic non-linear resistance element in correspondence to one display cell of the display cell matrix, said material having a preselected break-down voltage below which break-down voltage substantially no current flows through said material and above which break-down voltage substantial amounts of current can flow therethrough and with a voltage drop across said member being substantially equal to said break-down voltage;
and
means for coupling each matrix position of said member between an associated rear cell electrode defining a matrix cell and the row electrode associated with that rear cell electrode;
each matrix cell absorbing light incident thereon if the magnitude of a total driving voltage coupled between the column and row electrodes defining that cell in the display cell matrix is less than the sum of the break-down voltage of the non-linear material and the preselected voltage magnitude for the optically active material layer;
each matrix cell always reflecting light incident thereon if the magnitude of the total driving voltage coupled between said column and row electrodes defining that cel of said display cell matrix is greater than the sum of said break-down voltage and the preselected voltage magnitude for the optically active material layer.

7 more elements

A multiplexible display, comprising:

a plurality of reflective display cells each comprised of a front electrode;
a reflective rear electrode;
a layer of optically active material positioned between said front and rear electrodes;
said layer being switchable between a dark-appearing condition and a bright-appearing condition, responsive to the magnitude of a voltage between the front and rear electrodes of that display cell being respectively less than and at least equal to a preselected voltage magnitude;
each display cell being characterized by a predetermined value of electrical capacitance between said front and rear electrodes;
a member of an electrically non-linear resistive material having a plurality of positions defined thereon each forming a passive, non-linear resistive element in correspondence to one of the plurality of display cells;
said non-linear material having a preselected break-down voltage below which breakdown voltage substantially no current flows through said material and above which break-down voltage substantial amounts of current can flow therethrough with the voltage drop across the resistance element being substantially equal to said breakdown voltage;
each resistive element having an electrical capacitance thereacross less than the predetermined value of electrical capacitance of said display cell;
a plurality of first electrodes, each associated with at least one different one of the display cells;
means for coupling each position on said member of non-linear material between the rear electrode of the display cell associated with that position and that one of the plurality of first electrodes associated with that display cell;
and
a plurality of second electrodes, each coupled to at least one different one of the front electrodes of said plurality of display cells, with only one of the display cells coupled to any particular one of the second electrodes having the front electrode thereof coupled to a particular one of the first electrodes;
each display cell appearing respectively dark and bright only if the magnitude of a total driving voltage coupled between the first and second electrodes respectively coupled to the rear and front electrodes of that display cell is, respectively, less than and greater than the sum of the break-down voltage and the preselected voltage magnitude for the optically active material layer.

10 more elements

A multiplexible display, comprising:

a plurality of substantially parallel and substantially transparent elongated and continuous column electrodes arranged spaced each from the other in a first direction in a first plane, each of said column electrodes adapted for having a column driving voltage coupled thereto;
a plurality of reflective and substantially flat coplanar rear cell electrodes arranged spaced each from the others and extending in both said first direction and in a second direction, substantially transverse to said first direction, in a second plane parallel to, and spaced behind, said first plane;
a plurality of substantially parallel row electrodes situated in a third plane parallel to, and spaced behind, said second plane, said row electrodes arranged spaced each from the others in said second direction and with only one of the row electrodes positioned substantially parallel to an associated one of said rear cell electrodes, each of said row electrodes adapted for having a row driving voltage coupled thereto;
a layer of optically-active material positioned as the only element between said first and second planes, said layer having a plurality of display cells therein, each defined by the registration of one of said plurality of column electrodes and one of said plurality of rear cell electrodes;
the optically-active material in each display cell respectively absorbing therein and transmitting therethrough light entering said display cell responsive to the magnitude of the voltage between the portions of the column and rear cell electrodes defining said display cell being respectively less than and at least equal to a preselected voltage magnitude;
a member of an electrically non-linear resistive material having a plurality of positions defined thereon with each position in correspondence to one of said display cells, said material having a preselected break-down voltage;
a voltage across said member below said break-down voltage causing said material to always have a relative high resistance across said member and a voltage across said member above said breakdown voltage causing said material to always have a relatively low resistance across said member;
means for coupling each of said positions of said member between an associated rear cell electrode defining a display cell and a row electrode associated therewith;
each of said display cells absorbing light incident thereon if the magnitude of a total driving voltage coupled between the column and row electrodes defining that display cell is less than the sum of the break-down voltage of the non-linear material and the preselected voltage magnitude for the optically-active material layer;
and each of said display cells always reflecting light incident thereon if the magnitude of the total driving voltage coupled between said row and column electrodes defining that display cell is greater than the sum of said break-down voltage and the preselected voltage magnitude of the optically-active material layer.

7 more elements

Dependencies are inferred from the claim text.

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Abstract

A multiplexible matrix reflective display, comprising:

a plurality of substantially parallel and substantially transparent elongated and continuous column electrodes arranged spaced each from the others in a first direction in a first plane, each of said column electrodes adapted for having a column driving voltage coupled thereto;
a plurality of reflective and substantially flat coplanar rear cell electrodes arranged spaced each from the others in a matrix extending in both said first direction and in a second direction, substantially transverse to said first direction, in a second plane parallel to, and spaced behind, said first plane;
a plurality of substantially parallel row electrodes arranged spaced each from the others in said second direction and with only one of the row electrodes positioned substantially parallel to an associated row of said rear cell electrodes, each of said row electrodes adapted for having a row driving voltage coupled thereto;
a layer of optically active material positioned as the only element between said first and second planes, said layer having a matrix therein of cells each defined by the registration of one of said plurality of column electrodes and one of said plurality of rear cell electrodes;
the optically active material in each cell respectively absorbing therein and transmitting therethrough light entering said cell responsive to the magnitude of the voltage between the portions of the column and rear cell electrode defining said cell being respectively less than and at least equal to a preselected voltage magnitude;
a member of an electrically non-linear resistive material, positioned substantially parallel to the plane of at least said optically active layer and substantially covering the entire area of and in registration with said optically active layer, said member having a matrix of positions defined thereon with each position forming a passive, monotonic non-linear resistance element in correspondence to one display cell of the display cell matrix, said material having a preselected break-down voltage below which break-down voltage substantially no current flows through said material and above which break-down voltage substantial amounts of current can flow therethrough and with a voltage drop across said member being substantially equal to said break-down voltage;
and
means for coupling each matrix position of said member between an associated rear cell electrode defining a matrix cell and the row electrode associated with that rear cell electrode;
each matrix cell absorbing light incident thereon if the magnitude of a total driving voltage coupled between the column and row electrodes defining that cell in the display cell matrix is less than the sum of the break-down voltage of the non-linear material and the preselected voltage magnitude for the optically active material layer;
each matrix cell always reflecting light incident thereon if the magnitude of the total driving voltage coupled between said column and row electrodes defining that cel of said display cell matrix is greater than the sum of said break-down voltage and the preselected voltage magnitude for the optically active material layer.

7 more elements