Artificial nail sets are provided. In order to achieve the above object, optical beam is passed through a space surrounded by a tracking coil and a focusing coil which are adjacent to each other and fixed in a holder. Therefore, an accurate result can be obtained quickly when an existing memo or document is searched for desired content by inputting a query phrase using a digital pen. Accordingly, the present invention is advantageous in that it can reduce process steps for forming multiple metal layers, lower a step and cut manufacture cost.