Patent ID: 7917046

Claim:
A development device comprising: a toner carrying member that is disposed opposite an image carrying member and that adheres, by receiving a development bias composed of a first direct-current bias and a first alternating-current bias, toner to a surface of the image carrying member to develop an electrostatic latent image; and a toner supply member receiving a supply bias composed of a second direct-current bias higher on a same polarity side as a polarity of the toner than the first direct-current bias and a second alternating-current bias having a peak-to-peak value lower than a peak-to-peak value of the first alternating-current bias and forming with a magnetic brush a thin toner layer on the toner carrying member, wherein a potential difference between a peak voltage of the development bias on an opposite polarity side to the polarity of the toner and a peak voltage of the supply bias is set at a predetermined value or below, and a two-component developer including at least a carrier and the toner is used.