Abstract: A three-dimensional printing apparatus is provided. The three-dimensional printing apparatus includes a base, a printing head, a plurality of material-supplying spools and a switching unit. The base has a carrying surface. The printing head is disposed above the base. The material-supplying spools respectively include a plurality of construction materials. The construction materials have a plurality of characteristics, and the characteristics are different from each other. The switching unit is configured to selectively connect at least one of the spools to the printing head according to the characteristics. The construction materials of the selected material-supplying spools are dispensed on the carrying surface by the printing head.

Abstract: A data printing system and data protection method thereof are provided. The system includes a data output device and a data printing device. The data output device transfers data into a printing file that includes a plurality of file blocks. Also, the data output device sequentially classifies the file blocks into a plurality of sections with a preset number, and respectively generates a plurality of checksums according to the file blocks in each section. The data output device respectively appends the checksums to the sections and sequentially transmits the sections. The data printing device is connected to the data output device through a connecting interface, receives the sections and examines whether the file blocks in each section are correct according to the checksum of each section respectively. When the file blocks of each section are correct, the data printing device executes a printing job corresponding to the section.