Projection display has been growing up rapidly in the late 1990 ' s . this display technology integrates microelectronics , precision optical instrumentation and precision mechanical technology , and is becoming the one of the main stream in the present display field 投影显示技术是九十年代兴起的一种大屏幕显示技术,它集微电子技术、精密光学仪器技术以及精密机械技术为一体,已成为现代显示领域的主流。