The present invention comprises a line scan camera and a variable focus optical element. With the line scan camera, the three dimensional imaging system of the present invention can overcome the speed problems of the area sensor and the variable focus optical element (Micromirror Array Lens) can change depth as fast as the line scan camera refreshes for the next scan so that the line scan camera and the variable focus optical element can be coupled to control optical depth and the linear scan. With help of the present invention scheme, three dimensional scan can be achieved with only one path scan of the line scan. Scheme, apparatus, and method are disclosed in the present invention.