The size of a paper put in a tray for manual insertion is decided according to detectors provided in the tray. When detection precision of the paper size is not so high to determine paper size, it is instructed to specify a paper size manually. In another example, a paper size selection picture ...http://www.google.com.tw/patents/US5826156?utm_source=gb-gplus-share專利 US5826156 - Image forming apparatus
