A controlled paper transport arrangement utilizes a flexible belt which attracts the paper to its surface by the application of a reduced air pressure on the other side. In a preferred embodiment, the belt operates in a continuous loop and in combination with a vacuum feed roller, the belt and the vacuum...http://www.google.com.hk/patents/US4792249?utm_source=gb-gplus-share專利 US4792249 - Vacuum paper transport system for printer
