High-density print head
AssigneeMax Levy Autograph, Inc.
InventorDonald C. Sedberry
Life of this patent
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Abstract
The invention is a print head for a thermal or electrostatic printer, the print head being made from a high-density circuit. The high-density circuit includes conductors having a spacing less than about 0.005 inches, the conductors being disposed over a relatively large area. The circuit is defined by a pattern of grooves in a dielectric substrate, and a conductive material is deposited in the grooves, and heated so as to form a tight bond with the substrate. The resulting circuit is stable, rugged, and capable of producing an image of high resolution. The invention also includes a print head made from a multi-layered version of the circuit. The invention permits the production of black and white or color halftone images having very large numbers of grey scale levels, and exceptional resolution.
Claims15
A print head comprising at least one high-density electronic circuit, the circuit comprising a plurality of conductors, the conductors being formed in grooves in an electrically insulating substrate, each of said grooves having a width and a depth, the depth of each of said grooves being of the same order of magnitude as the width, the conductors being formed of a conductive cermet material, each of the conductors having a width which is less than about 0.005 inches, wherein there are spaces between adjacent conductors, the spaces having a width less than about 0.005 inches, the circuit extending over a total area exceeding about one square inch, the conductors having ends disposed near an image recording medium, wherein activation of selected conductors causes production of a picture element on said medium.
A print head comprising at least one high-density electronic circuit, the circuit having a plurality of conductors having a density of at least about 200 lines per inch, the circuit being made by the method comprising the steps of:
- a) coating an electrically insulating substrate with a thin layer of material which can resist an etchant,
- b) coating the etchant-resistant layer of material with a photoresist,
- c) exposing the photoresist to light, the light being directed through a phototool comprising a pattern representing the desired electronic circuit,
- d) developing the photoresist to expose the etchant-resistive layer of material in those locations corresponding to elements of the desired circuit,
- e) removing the exposed portions of said etchant-resistive layer of material,
- f) etching into the substrate, in those locations where the etchant-resistive layer of material has been removed, to form grooves in the substrate, each of said grooves having a width and a depth, the depth of each of said grooves being of the same order of magnitude as the width,
- g) filling the grooves with a cermet material capable of becoming electrically conductive and capable of bonding to the substrate upon the application of heat, and
- h) heating the substrate to a temperature sufficient to bond the cermet material to the grooves in the substrate, and to make the cermet material electrically conductive, the cermet material forming the conductors of the circuit,
- wherein the conductors have ends disposed near an image recording medium, wherein activation of selected conductors causes production of a picture element on said medium.
A print head comprising at least one high-density electronic circuit, the circuit comprising a plurality of conductors, the conductors being formed in grooves in an electrically insulating substrate, each of said grooves having a width and a depth, the depth of each of said grooves being of the same order of magnitude as the width, the conductors being formed of a conductive cermet material which substantially fills the grooves and is bonded to the grooves, each of the conductors having a width which is less than about 0.005 inches, wherein there are spaces between adjacent conductors, the spaces having a width less than about 0.005 inches, wherein the conductors have ends disposed near an image recording medium, wherein activation of selected conductors causes production of a picture element on said medium.
Dependencies are inferred from the claim text.