by Roman Gutierrez
CTO and VP of Engineering, Tessera Technologies
Auto focus (AF) is a common feature for digital still cameras (DSCs) to ensure that the object being photographed is in focus. However, AF has only recently been introduced into high-end cell phone cameras where the image quality, as well feature size and low cost, are critical requirements. The most common AF actuator for DSCs, the stepper motor, failed when applied to the cell phone market as it could not be miniaturized or stand up to the cell phone’s more stringent reliability testing. As a result, a variety of new technologies have emerged to fill this need, with MEMS technology leading the pack.