Multiple MEMS mirrors synchronization techniques, modeling, and applications

MEMS Mirrors provide a great way to spatially scan light and is being used for a wide range of applications such as raster scanning RGB light for Display Engines or scanning infra-red light for depth cameras (3D sensing) by using structured light or Time of Flight (TOF) techniques. Yet, in some cases it is required to deploy multiple MEMS Mirrors that ought to work in tandem, such as implementing a Display Engine for a binocular HMD (Head Mount Display, AR/VR/MR) generating two images, one per eye. In such a case, it is necessary to synchronize the movement of the MEMS mirrors, so that the images that are presented to the viewer, would create a homogenous and consistent image. Another possible use case is to increase the Field Of View, such as for an Automotive Lidar application, so that each Scanning Engine with a mounted MEMS Mirror would cover a subset of the scanned scene, yet collectively would provide an increased scanned FOV. The scanning of each segment by one Scanning Engine would be done sequentially and in a synchronized manner with the other Scanning Engines. This paper will present a viable synchronization mechanism for two main types of MEMS Mirror: Resonant Mirror and Quasi Static Mirrors. The paper will discuss the challenges and considerations of the System Clock, Master / Slave modes, overcoming jitter and noise and modeling by simulations the expected results. Additionally, the paper will present the actual results of such system implementation as a result of this work.