Flat panel display system having direct monitoring and overhead projection monitoring capability

摘要

A light distributing removable door assembly (and elements thereof) for a back-lit flat panel display subsystem wherein the subsystem is for direct viewing as a monitor and having overhead projection capability. The removable door assembly provides for back- lighting via a light pipe for direct viewing when installed in the subassembly. When the door assembly is removed, the active matrix LCD is semi-transparent and can be placed over the imaging screen (viewing side down) of an overhead projector such that the LCD color image can be thus projected. The lamps that provide the back-lighting remain within the display subsystem when the door is removed and a unique optical coupling is provided between the lamps and a light pipe within the door. A specialized bi-directional light extraction pattern is used on a light pipe of the removable door to provide effective and uniform light distribution over the LCD image. A clamping mechanism is also described within the removable door for securing the layers used in the door assembly. The clamping mechanism allows a reduction in a size of a junction formed between the lighting units of the subsystem and the removable door assembly.