P-126: Ultra-Compact LED based Image Projector for Portable Applications

By using a single high power Light Emitting Diode (LED) and a small size transmissive LCD very compact projectors, which can be run from batteries, can be built. Such a projector can be used in combination with or integrated into a PDA or digital camera to project images or presentations in a small size format, and would be used whenever a laptop would be unavailable or clumsy. For these types of applications the required flux can be low. We have build a very small (prototype) projector using a single, high power LED, a small LCD, and a small projection lens. The light output of such a configuration is in the range of 5 to 10 lm, which is sufficient for the projected image sizes as indicated above. In this paper we well describe the system and its performance and size, and elaborate on alternative configurations and performance.