PURPOSE: To synthesize data and to print them by supplying and storing the document data, the graphic data and the image data independently of each other.

CONSTITUTION: The data including those data on documents, patterns, images, etc. in each group are read out of a host computer 20 by an instruction given from a keyboard 9 and the stored in a RAM 2 together with block numbers. Then the order to print those blocks on a form and the distribution data (x, y) are supplied through the keyboard 9 and used as the control data. The corresponding distribution data is read out of the control data by a synthesizing command given from the keyboard 9 and its reading output position is decided. The block data on the RAM 2 is evolved to a dot pattern if necessary and outputted with synthesization to an image buffer. When this output is through to the image buffer, the contents of the image buffer are outputted as the image data.