A portable electronic apparatus has user input means (7,8), for example a keyboard, disposed in back-to-back relation to a display (25,26). The apparatus may be hinged such that it can be opened and closed in the manner of a book, in which case the display may be in two parts that can be brought together...http://www.google.com.tw/patents/US6107988?utm_source=gb-gplus-share專利 US6107988 - Portable electronic apparatus
