Abstract: A platen type scanner driving mechanism has a supporting structure which includes an upper casing and a lower casing. A fixed lever extends longitudinally with respect to the support structure between the upper casing and the lower casing. An optical module is slidable along the fixed lever and extends transversely to the fixed lever. A single pulling wire is fixed by two spaced apart locations proximal to the center of the optical module, and a driving unit which drives the single pulling wire. The single pulling wire drives the optical module which is in parallel motion with respect to the fixed lever. The relative disposition of the single pulling wire, driving unit, and the optical module, prevents the optical module from being swung during displacement, reduces loads applied to the driving mechanism and optimizes the driving unit's force.