DEVICE AND METHOD FOR DETERMINING RESOLUTION OF A MULTIPLE RESOLUTION SCANNER

The present invention provides a device and a method for determining the resolution of a multiple resolution scanner. The scanner comprises a housing with a transparent platform for placing a document, a scanning module movably installed in the housing, a driving device installed in the housing for driving the scanning module to scan the document, a calibration region installed in the housing with an identification mark, and a control circuit installed in the housing for controlling the operation of the scanner. The scanning module comprises a case with an opening on its top for receiving the light from the document, a sensor installed in the case for transforming the light from the document into corresponding image signals, a lens module installed in the case for converging the light from the document onto the sensor wherein the resolution of the lens module is variable, and a lens module control device installed in the case for changing the resolution of the lens module. The control circuit processes the image signals generated by the scanning module and controls the lens module control device to change the resolution of the lens module. When the control circuit determines the resolution of the lens module, it uses the driving device to move the scanning module into the calibration region, uses the scanning module to scan the calibration region to get the image signal corresponding to the identification mark, and then determines the resolution of the lens module according to the image signal corresponding to the identification mark.