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US 4,903,049 AGranted
Wrong sign toner extraction for a direct electrostatic printer
AssigneeXerox Corporation
InventorJohn D. Sotack
Life of this patent
Estimating the term…
Abstract
Direct electrostatic printing (DEP) is enhanced by the provision of wrong-sign toner extraction holes or apertures provided in a printhead structure at a location which is upstream of the printing apertures. Wrong sign toner particles are extracted from a cloud of toner provided from a toner delivery device. The wrong sign toner is extracted from the powder cloud before the cloud reaches the vicinity of the printing apertures thereby minimizing print hole blockage.
Claims8
Direct electrostatic printing apparatus, said apparatus comprising:
- a supply of charged toner particles including means for creating a toner cloud;
- an apertured printhead structure through which toner particles of one polarity from said toner cloud pass in image configuration;
- an image receiving member disposed adjacent one side of said apertured printhead;
- means for supporting said image receiving member for movement past said apertured printhead;
- means for effecting the attraction of toner particles from said apertured printhead structure to said image receiving member;
- and
- means forming an integral part of said apertured printhead for removing toner particles from said toner cloud, said removed toner particles being charged oppositely to the charge of toner particles attracted to said imaging surface.
4 more elements
The method of printing images, said method including the steps of:
- supplying a cloud of toner particles to an apertured printhead structure, said toner particles including both negatively and positively charged particles;
- supporting an image receiving member to one side of said apertured printhead structure;
- attracting toner particles of one polarity through apertures in said apertured printhead structure to said image receiving member in image configuration;
- and
- attracting toner particles of the opposite polarity to said printhead structure in an area thereof which is remote from said apertures.
2 more elements
Dependencies are inferred from the claim text.