Abstract

A system and a method of printing an image represented by a frame of image data utilize a hand-held printer having optical sensors for tracking positions of the hand-held printer relative to the surface of a print medium during a printing process. The change in position of the hand-held printer during the printing process is monitored in real time using navigation information generated by the optical sensors. Each optical sensor contains an array of optoelectronic elements to capture images of the surface of a print medium at fixed time intervals. Preferably, the optical sensors can detect slight pattern variations on the print medium, such as paper fibers or illumination patterns formed by highly reflective surface features and shadowed areas between raised surface features. These features can then be used as references for determining the position and the relative movement of the hand-held printer. During the printing process, the printed portions of the image can also be used as reference positions by the hand-held printer. In the preferred embodiment, the hand-held printer contains a navigation processor and a printer driver. Using the printer driver, the navigation processor drives the hand-held printer to print segments of the image onto a print medium as the hand-held printer travels across the print medium during a printing process. Each segment of the image is printed onto a particular location on the print medium to form a composite of the image.