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US 4,733,256 AGranted
Electrostatic color printer
OwnerPeter C. Salmoninventor
Life of this patent
Estimating the term…
Abstract
An electrostatic color printer incorporating an array of imaging electrodes controlled by special purpose integrated circuits, and a color drum having a charged multilayered particle screen to sequentially present color toners to the imaging array. The special purpose integrated circuits include low voltage, logic and memory circuits, high voltage circuits to drive the imaging electrodes and provide a direct path for the particles to the receiving print medium. The electrodes are arrayed to form a staggered linear array. The printer is capable of printing multiple colors with variable color density in each pixel position and the color image is printed with a single pass of the receiving print medium past the imaging head.
Claims21
An improved printhead for use with a toner delivery system capable of delivering charged toner particles, the printhead comprising:
- a baseplate;
- a multilayer conductive means attached to the baseplate;
- and
- at least one integrated circuit mounted on the conductive means, each of the integrated circuits having an array of imaging electrodes including logic, memory, and high voltage driver means associated therewith for selectively driving said electrodes between a first potential and a ground potential.
1 more element
An electrostatic color printer system comprising:
- a color drum having a plurality of toner compartments radially spaced about the drum and allowing travel of charged toner particles in a radial direction, a charged multilayered particle screen positioned about the periphery of the drum, and drive and control means for rotating the drum pursuant to control signals;
- a printhead arrayed in proximity and tangential to the drum, including a baseplate formed of a nonconductive material and including a plurality of apertures, a plurality of integrated circuits affixed to said baseplate, each integrated circuit including a plurality of imaging apertures formed therethrough with each aperture coaxial with one of said apertures of said baseplate, each of said imaging apertures further including an imaging electrode formed onto a second surface of each of said integrated circuits, and further including logic, control, and driver means for selectively switching said imaging electrodes between a first potential and a ground potential;
- a back electrode means capable of being charged to a second potential, and positioned to be in proximity to said baseplate;
- a printer control logic means for receiving inputs from an information source and delivering an output to the back electrode means and multiple outputs to said integrated circuits, whereby potentials may be delivered sequentially to said imaging electrodes and to the back electrode means to induce toner particles to migrate from each of said toner compartments on the color drum and to cluster on said common metal electrode of said multilayer particle screen, thence to be accelerated through said imaging apertures by said imaging electrodes and to impact upon said print medium under an influence of said second potential applied to the back electrode;
- and
- a fusing means to fix said toner particles onto said print medium.
3 more elements
An electrostatic color printer system comprising:
- a print media input means;
- a color drum having a plurality of toner compartments radially spaced about a periphery of the drum and allowing travel of a plurality of charged toner particles in a radial direction, said toner compartments being filled, in a repeating sequence, with toner of a first primary color, a second primary color, a third primary color and black, the color drum including drive and control means coupled thereto to rotate the drum;
- a multilayered particle screen covering said periphery of the drum, the particle screen comprising a metal screen secured adjacent to said toner compartments, a first thin dielectric sheet bonded to said metal screen, a plurality of abutting ring-shaped electrodes comprising a common metal electrode bonded to said first dielectric sheet and a second dielectric sheet covering said common metal electrode, said first and said second dielectric sheets and said metal screen including a plurality of apertures coaxial with each other and with each of said ring-shaped electrodes, said apertures arranged in staggered rows about the surface of the particle screen, said metal screen having a first potential applied thereto and said common metal electrode having a second potential of the same sign but greater magnitude than said first potential applied thereto;
- a baseplate formed of a nonconductive material and having a plurality of apertures formed therethrough and in staggered rows, each aperture in a row being separated by a distance which is less than a width of each aperture whereby overlapping pixels may be produced;
- a plurality of special purpose integrated circuits affixed to the baseplate about a first surface of each integrated circuit and including a plurality of imaging apertures formed therethrough to coincide with said baseplate apertures, each imaging aperture including an imaging electrode formed around each of said apertures and onto a second surface of each integrated circuit, the special purpose integrated circuits including logic, control and driver means associated therewith for selectively switching said imaging electrodes between a third potential and a ground potential, said third potential being of the same sign as said first and second potentials and approximately equal in magnitude thereto;
- a back electrode capable of being charged to a fourth potential opposite in sign from said first potential, the back electrode positioned to be tangential to the color drum and of approximately equal length and further positioned to be in proximity to the baseplate whereby a sheet of print medium may be inserted between the baseplate and the back electrode;
- a printer control logic means capable of receiving input data from an information source, said data including pixel data, and for delivering an output to the back electrode, to the special purpose integrated circuits, and to said metal screen and said common metal electrode of the particle screen whereby potentials may be delivered sequentially to said imaging electrodes and the back electrode to induce a plurality of charged toner particles to migrate from said toner compartments to cluster on said common metal electrode of the particle screen, thence to be accelerated through said imaging apertures by said imaging electrodes and to impact upon said print medium under an influence of said fourth potential applied to the back electrode;
- a fusing means disposed downstream from said baseplate and special purpose integrated circuits, the fusing means adapted to fix said plurality of toner particles onto said p int medium;
- and
- a print medium output means for receiving said print medium after printing.
7 more elements
An electrostatic color printer system comprising:
- a color drum having a plurality of toner compartments radially spaced about the drum and allowing travel of charged toner particles in a radial direction, a charged multilayered particle screen positioned about the periphery of the drum, and drive and control means for rotating the drum pursuant to control signals;
- a printhead arrayed in proximity and tangential to the drum including a baseplate formed of a nonconductive material and including a plurality of imaging apertures with an imaging electrode formed about each of said apertures, a plurality of electrically conductive elements affixed to said baseplate, and further including logic, control, and driver means connected to said electrically conductive elements and to said electrodes for selectively switching said imaging electrodes between a first potential and a ground potential;
- a back electrode means capable of being charged to a second potential and positioned to be in proximity to said baseplate;
- a printer control logic means for receiving inputs from an information source and delivering an output to the back electrode means and multiple outputs to said logic means, whereby potentials may be delivered sequentially to said imaging electrodes and to the back electrode means to induce toner particles to migrate from each of said toner compartments on the color drum and to cluster on the outer surface of said multilayer particle screen, thence to be accelerated through said imaging apertures by said imaging electrodes and to impact upon the print medium under an influence of said second potential applied to the back electrode;
- and
- a fusing means to fix said toner particles onto said print medium.
3 more elements
An electrostatic color printing system comprising:
- a toner delivery system having a plurality of toner compartments filled with toners of different colors, such that the colored toners are sequentially presented to the surface of the print medium for imaging by the printhead;
- a printhead arrayed in proximity to the toner delivery system including a baseplate, a multilayer conductive means, and at least one integrated circuit affixed to the conductive means, each of the integrated circuits including an array of imaging electrodes including logic, memory, and high voltage driver means associated therewith for selectively driving said electrodes between a first potential and a ground potential;
- a printer control logic means for receiving inputs from an information source and delivering multiple outputs to said intergrated circuits, whereby potentials may be delivered sequentially to said imaging electrodes to selectively induce toner particles to leave said toner compartments, accelerated by the potential on said imaging electrodes to impact on said print medium;
- and
- a fusing means to fix said toner particles onto said print medium.
2 more elements
Dependencies are inferred from the claim text.