Patent ID: 6076983
Filing Date: 2000-06-20
Classification: B41J

Abstract:
An apparatus for printing on a continuously advancing web of work material comprising:a frame;means for continuously advancing said web in an X coordinate direction longitudinally of itself at a velocity v.sub.wx relative to said frame;at least one print head coupled to said frame for movement relative thereto, said print head including a plurality of print elements arranged in a scanning array extending in said X coordinate direction;means for repetitively moving said scanning array relative to said frame along a path including at least one scan segment and at least one repositioning segment at such a velocity v.sub.a related to said web velocity v.sub.wx that as said scanning array traverses said scan segment of the path said scanning array has a first velocity component v.sub.ax in said X coordinate direction, and a second velocity component v.sub.ay in a Y coordinate direction perpendicular to said X coordinate direction;said means for repetitively moving said scanning array of print elements further being such that said first velocity component v.sub.ax is equal to v.sub.wx so that said scanning array in traversing said scan segment of the path scans a swath on said web parallel to said Y coordinate direction and having a swath height h.sub.s ;said means for repetitively moving said scanning array of print elements further being such that said second velocity component v.sub.ay is such that in the time required for moving said scanning array along the full extent of said scan segment of the path said web advances a distance h.sub.w in said X coordinate direction that is less than said swath height; and whereinupon traversing said scan segment said scanning array travels along said repositioning segment such that prior or equal to a time taken for said web to advance a distance d, where d=h.sub.s -h.sub.w, said print head is repositioned for immediate movement along a scan segment thereby causing successive swaths of said web scanned by said scanning array to be positioned on said continuously advancing web immediately adjacent to one another.