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US 4,087,826 AGranted
Pulsed electrical printer with dielectrically isolated electrode
AssigneeEPP Corp.
InventorRobert W. Haeberle
Life of this patent
Estimating the term…
Abstract
A non-impact printer for transferring printing particles from a donor sheet to a recipient sheet by applying pulses to produce an electrical field between a print electrode and a base electrode. The print electrode comprises a conductive member having a field shaping surface corresponding in shape to an image to be printed. The electric field passes through dielectric material between the field shaping surface and the donor and recipient sheets, the dielectric material being chosen for its stability against breakdown in high electric fields.
Claims9
Apparatus for pulsed electrical printing having, in combination,
- a print electrode comprising a body of dielectric material having a breakdown strength substantially greater than that of air, said body having a first surface, and a conductive member having a field shaping surface spaced from and facing said first surface and a lateral surface contiguous with the field shaping surface and extending therefrom away from said first surface, said field shaping and lateral surfaces being embedded in said dielectric material,
- means to put a donor sheet bearing conductive printing particles and a recipient sheet adjacent to and facing said first surface, and
- means to establish an electrical field of short duration between the particles and said conductive member, said field having sufficient amplitude to establish a current flow which charges said particles and causes them to detach from the donor sheet and move to the recipient sheet, but insufficient magnitude to produce a breakdown of said dielectric material between said first and field shaping surfaces.
Dependencies are inferred from the claim text.