An imaging device for producing multicolor images from image data
containing data representing an image of a first color and an image of a
second color to be registered relative to the image of the first color
onto a substrate by transferring toner of the first and second colors to
the substrate is provided. The imaging device includes a first imager, a
second imager, a photoreceptor belt, a plurality of rollers mounted to a
frame of the imaging device, an angular position sensor, an image data
source and a controller. The plurality of rollers define a process path
along which the photoreceptor belt is driven past the first and second
imagers in a process direction. The plurality of rollers includes a drive
roller that exhibits an eccentricity for which a formula relating angular
position as a function of the phase angle of the drive roller to
eccentricity is known. The angular position sensor detects the phase
angle of the drive roller. The image data source generates image data
that includes a line to be printed in the first color and in the second
color. The controller is coupled to receive signals from the angular
position sensor, ROS imager and image data source and is configured to
drive the second imager to generate an optical output. The controller
includes memory and a processor. The memory stores the formula relating
angular position as a function of the phase angle of the drive roller to
eccentricity. The processor calculates an appropriate time delay for
starting the generation of the optical output of the second imager for
printing the line to be printed in the first color and in the second
color based on the time of the starting of the optical output by the ROS
imager to print to print that line, the signal received from the angular
position sensor, and the formula relating angular position as a function
of the phase angle of the drive roller to eccentricity.