Printable Field Emitters Limited

Emi-varian Limited

Tatung Company

Printable Fields Emitters Limited

Printable Field Emitter Limited

Richard Allan Tuck

Hugh Bishop

Tzung-Han Yang

Christopher Hood

Chi-Tsung Lo

Warren Lee

William Taylor

Rodney Vaughan Latham

Heather B Skinner

Adrian Burden

Peter Graham Adpar Jones

A substrateis provided with conductive cathode tracks and a field electron emission material on the tracks. Septaand pillarsare provided as raised elements over the emission material. An electrically insulating layer is formed over the emission material and raised elements, such that boundary walls are formed in the insulating layer where it contacts the raised elements. The raised elementsare then removed, to leave emitter cells and voids for other components, defined by the boundary walls with the insulating layer. A gate electrode is provided over the insulating layer.

Cathode planes for field emission devices

A field electron emission material is created by applying a silica precursor to graphite particles (); processing the silica precursor to produce amorphous silica () which is doped and/or is heavily defective, and disposing the graphite particles () upon an electrically conductive surface () of a substrate () such that they are at least partially coated with the amorphous silica ().

Method of creating a field electron emission material

A masking layer () is provided on selected areas of an electrode structure that is at least partly performed, to define masked areas and unmasked areas (emitter cells). A first constituent with particles () and a second constituent () are then applied to the emitter cells (), and the particles () are selectively directed towards the bottoms of the emitter cells ()&#x2014;e.g. by electrophoresis. The masking layer () is then removed from the masked areas, together with any stray quantities of the first and second constituents () on the masking layer (). The first and second constituents () are then processed (e.g. by curing) to create broad area field electron emission sites in desired locations of the electrode structure.

Field emitters and devices

A field electron emission cathode is manufactured by depositing on an insulating substrate , by low resolution means, a sequence of a first conducting layer , a field emitting layer and a second conducting layer to form at least one cathode electrode. There is then deposited on the cathode electrode by low resolution means, a sequence of an insulating layer and a third conducting layer , to form at least one gate electrode. The structure thus formed is then coated with a photoresist layer . The photoresist layer is then exposed by high resolution means to form at least one group of emitting cells, the or each such group being located in an area of overlap between a cathode electrode and gate electrode. To complete the cells, the conducting and insulating layers are etched sequentially to expose the field emitting layer in the cells, and remaining areas of the photoresist layer are removed. Thus, field emitting materials and devices can be manufactured using relatively low cost techniques.

Method of manufacturing a field electron emission cathode having at least one cathode electrode

A field electron emission material is formed by coating a substrate ( ) having an electrically conductive surface with a plurality of electrically conductive particles ( ). Each particle has a layer of electrically insulating material ( ) disposed either in a first location between the conductive surface of the substrate ( ) and the particle ( ), or in a second location between the particle ( ) and the environment ( ) in which the field electron emission material is disposed, but not in both of such first and second locations, so that at least some of the particles ( ) form electron emission sites at such first or second locations. A number of field emission devices are disclosed, utilizing such electron emission material.

Field electron emission materials with insulating material disposed in particular area and devices

A field electron emission material has a substrate with an electrically conductive surface. Electron emission sites on the conductive surface each include a layer of electrically insulating material to define a primary interface region between the conductive surface and the insulating layer, and a secondary interface region between the insulating layer and the vacuum environment,. Each primary interface region is treated or created so as to enhance the probability of electron injection form the conductive surface into the insulating layer. Each primary interface region after such treatment or creation is either an insulator or graded from conducting adjacent the conductive surface to insulating adjacent the insulating layer.

Field electron emission materials and devices

A thermionic cathode (FIG. 1) comprises a porous matrix of tungsten (4) impregnated with alkaline earth activator. A coating (5) 1 .mu.m thick is formed on the matrix (4). The coating is of .sigma. phase alloy of molybdenum and osmium. Alternative .sigma. phase alloys are disclosed, and various methods of making cathodes are disclosed.

Thermionic electron emitters and methods of making them

A thermionic electron emitter comprises a tube of wall thickness less than 0.1 mm, a body of thermionic electron emissive material compressed and sintered in the tube, and a ring, coaxial with the tube, within the body to provide constraint against cracking of the body.

Thermionic electron emitter

An electron emitter comprises field emitter zones formed by projections of field emissive material separated by regions which are not field emissive. An extractor electrode for applying an electric field to the projections and a focus electrode have openings aligned with the emitter zones and material particles aligned with the non-emissive regions. The electrodes form, when suitably energised electron focussing fields to focus electrons emitted from the zones.

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Slough, United Kingdom

Richard Allan Tuck