CP+ 2015: Sony shows off new technology
CP+ 2015: Sony Stand Report
In contrast, here's a look at the linear motors used for electromagnetic driving of the lens focus group for contrast-detect autofocus. The lens' focus group is moved back and forth until maximum contrast is achieved at the desired focus point. Have a look at a video of the linear motor in the Sony Zeiss Sonnar T* FE 55mm F1.8 ZA lens in operation here.