Fast Printing - Make Inkjet Head the same width as the paper.
I remember printing an A4 photo in the early 1990's with an Epson photo printer - these had the highest dpi available and therefore the highest assumed quality. Something the advert didn't say was that it would take over half an hour, oh and you couldn't just leave it printing in the background while you took the dog for a 10 mile walk, as the paper pick up roller wouldn't usually feed the paper through.
Move forward in time to 2007.... a new development has been made by Brother, very clever and simple; they have invented a new printing head that doesn't move! The printer's head is as wide as the media or paper, taking away a massive time and process drain, so with the new printer the paper passes through - at break kneck speed - as the ink is fired onto the paper through the printer head. In order that the paper doesn't have to pass through the printer three times there is a separate head for each colour and these all work at the same time.
This produces an amazing print speed of up to 800mm/ second and was recently demonstrated producing 150 full colour A6 pages per minute. Although the a6 size is only small - brother are working on joining the heads together side by side, to make a wider print area. They are talking about their new generation of printers being able to produce photo quality posters in the near future at incredible speeds. Let's hope that the ink tanks are upgraded to cope with the extra work :-)