Patent attributes
A method is described for calibrating a linear printhead including an array of light sources. A test target is printed by activating the light sources in the printhead in accordance with digital image data for the test target, wherein a current value for each light source is controlled responsive to an initial set of current control parameters. A digital image capture system is used to capture an image of the printed test target, and the captured digital image is analyzed to determine an estimated exposure gain error for each light source. An updated set of current control parameters is then determined which is adapted to compensate for the estimated exposure gain errors.