Compensation for aerodynamic influences in ink jet apparatuses having ink jet chambers utilizing a plurality of orifices

Claim 1

In scanning impulse ink jet apparatus for printing bars in a bar code on a recording medium, the apparatus including a plurality of side-by-side chambers that extend along a line that is slanted with respect to the direction of scanning, each of the chambers including a plurality of grouped orifices that area arrayed along a line which extends at a right angle to the scanning direction, and means, including a plurality of transducers, for ejecting a plurality of droplets from the grouped orifices of each chamber to form dots on the recording medium, wherein a plurality of the dots overlap to form a pixel of a known height, one of the transducers being coupled to each of the chambers, a method of compensating for aerodynamic effects on the droplets ejected from the plurality of orifices for each of the chambers comprising the steps of: selecting a center-to-center distance between the dots forming a single pixel; spacing apart each orifice in the plurality of orifices for each of the chambers form the adjacent orifices in its respective plurality of grouped orifices a predetermined center-to-center distance that is greater than said center-to-center distance between the dots formed on the recording medium by said adjacent orifices such that the overall field of dots formed by droplets ejected from each of the plurality of grouped orifices prints one pixel of a bar without a gap with the overall field of dots formed by droplets ejected from another plurality of grouped orifices which print an adjacent pixel of the bar.