US 5,771,054 AGranted

Heated drum for ink jet printing

AssigneeXerox Corporation

InventorsLesley P. Dudek, Vaughan Louis Dewar, Dale R. Ims, Michael C. Ferringer

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Abstract

An ink jet printing system utilizes a heated rotary printing drum for mounting and carrying paper to be printed by one or more thermal ink jet printheads to achieve black or full color printing at high speed. As printing and drying are achieved prior to any transfer of the sheet from the drum, smudging of images is prevented. Such a printing system is capable of producing dried prints that can be immediately stacked and handled without smudging using slow-drying black inks and fast-drying color inks at speeds exceeding 10 pages per minute for color and 20 pages per minute for monochrome black text or images. Hold down of the sheet onto the drum can be achieved using vacuum or electrostatic forces to precisely retain the sheet on the drum until printing and drying are completed. Partial tone printing on multiple passes of the heated drum is provided to eliminate mottle on large solid areas. Heating of the drum can be performed internally or externally.

Claims27

Dependent claims

A high-speed inkjet printer comprising:

a sheet input tray for storing a sheet prior to printing, the sheet having a predetermined length;
a sheet output tray for storing printed sheets;
a heated rotary printing drum provided downstream from said sheet input tray;
a sheet input path located between said sheet input tray and said heated rotary printing drum for transporting the sheet from said sheet input tray to said heated rotary printing drum, said heated rotary printing drum acquiring and precisely registering the sheet from said sheet input path such that the sheet is in contact with an outer surface of said heated rotary printing drum, a circumferential length of said heated rotary printing drum being greater than the length of the sheet;
at least one ink jet printhead located for printing an image onto the sheet while the sheet is registered on said heated rotary printing drum;
and
an exit sheet path located downstream of the heated rotary printing drum for receiving the sheet from the heated rotary printing drum and transporting the sheet from said heated rotary printing drum to said sheet output tray,
wherein said heated rotary printing drum is rotated a plurality of complete revolutions to transport the sheet a plurality of times past said at least one ink jet printhead for printing the image onto the sheet, said heated rotary printing drum being provided with a heat source that transfers heat energy to the sheet acquired on said heated rotary printing drum as the sheet is rotated past said printhead, at least one complete revolution of said heated rotary printing drum being provided after printings thereby sufficiently drying the sheet and ink printed on the sheet prior to transfer of said sheet from said drum to said exit sheet path.

5 more elements

Dependencies are inferred from the claim text.