BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram which shows an image forming apparatus according to an embodiment of the invention;
FIG. 2 is an external perspective view of the image forming apparatus of FIG. 1;
FIG. 3 is a block diagram which shows an electrical arrangement of the image forming apparatus of FIG. 1;
FIGS. 4A, 4B and 4C are schematic diagrams each showing a stop position of the developing unit;
FIGS. 5A and 5B are developed views each showing an arrangement of the intermediate transfer belt;
FIG. 6 is a flow chart which shows the image forming operation in this apparatus;
FIG. 7 is a flow chart which shows the quartet monochrome mode;
FIGS. 8A, 8B and 8C are drawings which show the arrangements of images on the intermediate transfer belt; and
FIGS. 9A, 9B, 9C and 9D are drawings of examples that the toner image arrangement in the quartet monochrome mode is modified.