An aspect of the present invention is a method of forming a contact in a thin-film device. In certain embodiments, the systems and methods allow a vehicle battery sensing circuit andor other associated system to measure a compensation parameter. The optical scanning module generates plural projection points along plural scan lines on a projection surface according to a sequence signal. The printing ratios of the plurality of scanning operations are controlled to set the printing ratio of the final scanning operation lower than the average one of the remaining scanning operations in a unit area where the ink discharge amount is larger than the predetermined threshold.