Special Aspects of Quality Control and Color Management in an Ink Jet Minilab

摘要

Recently ink jet technology has begun to enter the photo finishing business. One of the biggest challenges for ink jet systems is, however, to reach the speed of a few hundred 4 x 6" pictures per hour like the conventional minilabs do. Approaches to reach that goal are, to combine several ink jet print heads and/or to increase their speed relative to the paper. This higher speed leads to new quality and color management problems, which are not existent or less severe under desktop printing conditions. In this paper we present our investigations on the quality of printed dots in dependence on scanning speed. The higher speed reduces dot placement accuracy and it can cause degradation of dot quality. Effects like elongated dot shapes or even separation of main drop and satellite drop have been observed. These microscopic effects cause image quality problems like increased banding or large color shift compared to the prints at normal speed. Print parameters like speed of the print heads relative to the paper, waveforms to drive the print heads and the distance between print head and paper can not be considered independently and have to be adjusted properly to obtain best print quality.