A gravure coating apparatus is provided for forming a stripe-shaped coating film by means of a gravure roll having a groove between plate cylinders. A multi-faceted star is affixed atop a telescoping support post, the bottom of which is attached to a support base housing a battery or electrical power pack. The processing circuit is configured to sequentially obtain a plurality of images through sensing the two lights by a plurality light sensors, determine the corresponding light source generator of each one image according to the predetermined sequence, and further determine position information of the corresponding light source generator according to image information of the one image.