Contact image scanner with multi focal length and multi resolution

The image scanner includes following parts: at least a first circuit board and a second circuit board; at least two sets of sensitizing element array (SEA) composed of first set of SEA and second set of SEA located on the first circuit board and the second circuit board respectively; at least one set of columnar lens composed of first and second columnar lenses; first columnar lens and second columnar lens suspended on the corresponding first set of SEA and second set of SEA; a glass is suspended on the set of columnar lens; adjusting relative position between the first circuit board and the second circuit board makes the two sets of SEA and the set of columnar lens form at least two focuses and resolutions in order to scan different objects to be scanned on the glass.