Patent ID: 7885564

Claim:
An image-forming device comprising: an image acquiring unit that acquires image data for one page; an image forming unit that forms an image based on the image data, the image forming unit including; a developing roller that carries a developer; a supply roller that supplies the developer to the developing roller; and a bias applying unit that applies a first voltage between the developing roller and the supply roller in a first mode, and applies a second voltage between the developing roller and the supply roller in a second mode; a determining unit that determines whether the image data includes a part having density greater than or equal to a prescribed density; and a controller that controls the bias applying unit to apply the first voltage when the determining unit determines that the image data does not include the part having density greater than or equal to the prescribed density, and to apply the second voltage when the determining unit determines that the image data includes the part having density greater than or equal to the prescribed density.