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(11) | EP 0 890 437 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A liquid ink printing apparatus and system |
| (57) A new printing system is disclosed for drop on demand printing. This printing mechanism
divides the printing process into two stages; a drop selection means to select drops
to be printed which generates a difference in meniscus position between selected drops
and unselected drops of fluidized ink; and a drop separation means, attracting the
ink of said drops to a substrate, the attraction being insufficient to overcome the
surface tension of drops in an unselected meniscus position but being sufficient to
overcome the surface tension of drops in a selected meniscus position so as to cause
movement of the drops to the substrate. The drop selection means can produce a difference
in meniscus position in the absence of the drop separation means. The separation of drop selection means from drop separation means significantly reduces the energy required to select which ink drops are to be printed. Only the drop selection means must be driven by individual signals to each nozzle. The drop separation means can be a field or condition applied simultaneously to all nozzles. |