Developing device

A developing device, comprising:

• an image carrier, on which an electrostatic latent image is formed;
• a first roller, opposed to the image carrier with a gap in between;
• a second roller, being in contact with the first roller such that toner of a one-component type is supplied onto the image carrier by way of the first roller to develop the electrostatic latent image as a visible toner image;
• a single power source, which supplies a bias voltage in which an AC voltage is superposed on a DC bias voltage, the bias voltage being supplied to the first roller through a first path and to the second roller through a second path;
• and
• a resistor, provided on the first path between the first roller and a branching point of the first path and the second path,
• wherein the resistor has such a value that a potential difference between the first roller and the second roller converges on a reference value within a time period during which a potential difference between the first roller and the image carrier is such a value that charged toner is supplied from the first roller to the image carrier.