To switch and print multivalued print data and binary print data by a small image-forming apparatus.

A light-emitting element of a light-emitting part 2 emits light by energy corresponding to a multivalued print data DA. Accordingly, printing is realized in an energy gradation method. The light-emitting element is turned on and off in accordance with a binary print data DB. Printing in an area gradation method is thus realized. The light-emitting element is driven in accordance with either of the print data by switching the multivalued and binary print data DA, DB.