If you separate the two functions of scanning and printing, you can easily get much smaller by getting a portable printer and scanner designed for notebook use. Combining the functions effectively forces a flatbed scanner attached to the printer and that limits the minimum size. Separating them can make them much smaller but as you do that there are other compromises that happen. I've seen 1.5" x 2.5" x 10" printers (that print on thermal paper) and hand scanners that are only appropriate for business cards or a full page scanner similar in size to the portable printer.