Design of micro-LED pico-projection optical engine based on an image fiber

Micro light-emitting diode (Micro-LED) has the advantages of high brightness, low power consumption, and long life. It has great potential and broad application prospects. Using micro-LED as the light source and image source of the projection system can greatly reduce the size and power consumption of the system. However, the electrical module and the optical module of the micro-LED pico-projection system cannot be separated. This paper uses image fiber to effectively separate the electrical module and optical module in the optical engine, and designs a micro-LED pico-projection optical engine based on an image fiber. This optical engine is composed of a projection lens group, an image fiber and a micro-LED. The projection lens group is composed of 5 spherical lenses, with the total length of 6.752mm and the focal length of 2.8mm. The modulation transfer function (MTF) is higher than 0.8@32lp/mm, and the distortion is below 2%. The image fiber adopts a multi-core fiber with a diameter of 2mm and a resolution of 32lp/mm. Finally, the overall simulation model of the optical engine is built to prove its feasibility.