Electroluminescent device

Claim 2

A matrix addressable electroluminescent display device comprising: a plurality of composite structures arranged in an array, each of said structures comprising a region of zero bias memory material adapted to block current below a threshold voltage and to pass current above said threshold voltage, said zero bias memory material retaining its last state under zero bias condition, each of said composite structures also comprising a region of electroluminescent material and a pair of electrodes between which said regions of zero bias memory material and electroluminescent material are disposed at least one of said pair of electrodes being transparent, and means for selectively applying an electrical field across individual pairs of electrodes whereby visual data is formed on said display device.

Claim 3

The apparatus of claim 1 wherein said zero bias memory material has variable resistance states for varying the state of luminescence of said electroluminescent material.

Claim 4

The apparatus of claim 1 including a capacitive control impedance in series with said composite structures.

Claim 5

The apparatus of claim 1 including pairs of transparent electrodes whereby said display device may be viewed from both sides.

Claim 6

Electroluminescent apparatus comprising: a pair of electrodes, at least one of which is light transparent, electroluminescent material interposed between said pair of electrodes, and zero bias memory material having a low and a high conductive state and being interposed between said pair of electrodes, said memory material switching from one of said two conductive states to the other of said two conductive states when a potential applied thereacross exceeds a threshold potential level and remaining in said one of the two conductive states, even after the potential applied thereacross is reduced to zero until said the other of said two conductive states is driven back externally to said one of said two conductive stateS wherein said memory material activates and deactivates said electroluminescent material to luminesce selectively as its conductive state changes.

Claim 7

Electroluminescent apparatus comprising: a pair of electrodes, at least one of which is light transparent, electroluminescent material interposed between said pair of electrodes, and zero bias memory material having a low and a high conductive state and being interposed between said pair of electrodes, said memory material switching from one of said two conductive states to the other of said two conductive states when a potential applied thereacross exceeds a threshold potential level and remaining in said one of the two conductive states, even after the potential applied thereacross is reduced to zero until said the other of said two conductive states is driven back externally to said one of said two conductive stateS wherein said memory material activates and deactivates said electroluminescent material to luminesce selectively as its conductive state changes.

Claim 8

The apparatus of claim 5 wherein said electroluminescent material is positioned in series with said zero bias memory material between said electrodes.

Claim 9

The apparatus of claim 5 wherein said electroluminescent material is positioned in parallel with said zero bias memory material between said electrodes.

Claim 10

The apparatus of claim 5 wherein said zero bias memory material is adapted to revert to its low conducting state when subject to a source of radio frequency radiation or high amplitude pulses.

Claim 11

The apparatus of claim 5 comprising: zero bias memory material adapted to have variable resistance states between said low and said high conducting states for varying the state of luminescence of said electroluminescent material.

Claim 12

The apparatus of claim 5 wherein said zero bias memory material and said electroluminescent material are combined in a heterogeneous mixture in an epoxy binder material whereby the background and image areas of said apparatus may be made to alternately brighten and darken with change in the voltage applied to said electrodes.

Claim 13

The apparatus of claim 5 wherein said zero bias memory material comprises an amorphous or polycrystalline film of semiconductor material selected from the group of metal oxides consisting of zinc, copper, lead, manganese, mercury and aluminum.

Claim 14

The apparatus of claim 5 wherein said zero bias memory material comprises a semiconductor material of reduced metal oxides.

Claim 15

The apparatus of claim 5 comprising a control impedance in series with said electrodes.

Claim 16

The apparatus of claim 13 wherein said control impedance comprises a layer of resistive material overlaying one of said electrodes and in electrical series with said electrode.

Claim 17

The apparatus of claim 13 wherein said control impedance comprises a capacitor in series with said electrodes.