39.3: Single Packaged RGB LEDs with Recycling for Pocket and Pico‐Projectors

Abstract

AbstractWith the advancements in the LED development, it becomes possible to have projectors made using LEDs as the illumination light sources, that fit into shirt pockets and small enough to be integrated into cell phones. Similar to the development and commercialization of cell phone cameras, in order to have a high adoption rate, the cost has to be low, which requires low component count and simple construction. To achieve low cost, the most important factor is to use less number of components, and small imager chips, which is one of the most costly component in the system. The use of smaller imager increases the illumination requirements. The limitation of LED brightness requires light recycling to increase the system brightness, effectively matching the illumination etendue to that of the imager chips. This paper presents an integrated approach to the illumination system by recycling using RGB LEDs assembled into a single package suitable for simple optical configuration and low cost.