The image forming apparatus is capable of changing a state between a first state in which only a first image bearing member and transfer belt contact each other, and a second state in which respective image bearing members are separated from the transfer belt. The systems utilize step-up converters or inverters, or dual-voltage batteries, to provide a voltage high enough to deice a windshield in less than thirty seconds at ambient temperatures above \u221210 C. In one embodiment, main preambles are written on a magnetic disk at a frequency of a data clock.