Eastman-kodak Company

Donald J Hodge

Douglas W Couwenhoven

Steven A Billow

James S Newkirk

Kenneth D Stack

A method of selecting inkjet nozzle banks for assembly into an inkjet printhead. The printhead when assembled includes at least two nozzle banks and is operative for printing one particular color ink or other liquid and each nozzlebank includes plural nozzles. The printhead is operational in a printer to print raster rows so that at least one raster row is printed using ink drops deposited at respective different pixel locations on the raster row by respective different nozzles on each of the at least two nozzle banks. The method includes (a) characterizing a drop size parameter for predetermined nozzles of each of the nozzle banks; (b) identifying for each of plural raster rows the respective different nozzles on each of the at least two nozzle banks that would be used to print the respective raster row; (c) identifying a size characteristic associated with each of the plural raster rows using a predetermined computer algorithm without printing the raster rows; and (d) determining in accordance with a criterion and data derived from size characteristic identified in step (c) whether or not the at least two nozzle banks are an acceptable match.

Method of selecting inkjet nozzle banks for assembly into an inkjet printhead

A thermal printer includes motor control apparatus for variably controlling the rotational speed of a take-up spool used to wind-up an expended dye-bearing donor web after passage through a print zone. The donor web is moved through the print zone at a substantially constant velocity by a rotatably driven print drum which cooperates with a thermal print head to unwind the donor web from a supply spool. The motor control apparatus operates to rotate the take-up spool at a speed inversely proportional to the instantaneous take-up spool diameter, whereby the expended donor web is accummulated at a rate slightly slower than the rate at which it is payed-out of the print zone during the printing operation. Preferably, the desired rate of rotations of the take-up spool, which gradually decreases with the number of prints made, is determined by the use of a shaft encoder mounted on the support shaft of the supply spool. During the production of thermal prints, the output of such shaft encoder is used to control a variable speed motor which appropriately decreases the rotational velocity of the take-up spool to maintain a zero tension in the web between the print zone and take-up spool. By eliminating tension on the donor web during printing, certain tension-produced artifacts in the thermal print are avoided.

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Rochester, NY, United States of America

Donald J Hodge