Image forming apparatus and rotary developing device

An image forming apparatus comprising:

• an image carrier that holds a toner image formed by developing an electrostatic latent image formed thereon with toner;
• a rotary developing device including a rotation shaft and a plurality of developing units supported on a revolution orbit surrounding the rotation shaft, the rotary developing device developing the electrostatic latent image on the image carrier with the toner by revolving the developing unit used for a current development operation, of the plurality of developing units, to a position opposing the image carrier and supplying the toner from the developing unit opposing the image carrier to the image carrier;
• a foreign-substance receiving plate that extends along the revolution orbit of the developing units in a lower part of the rotary developing device and receives a falling foreign substance;
• a transfer unit that transfers the toner image from the image carrier onto a recording medium;
• and
• a fixing unit that fixes the toner image transferred by the transfer unit onto the recording medium,
• wherein each of the developing units includes a developer container that stores developer containing magnetic carriers and toner electrostatically attached to the magnetic carriers, and a developing roller having a magnet therein, and the developing roller supplies the toner in the developer stored in the developer container for development of the electrostatic latent image on the image carrier by transporting the developer to the position opposing the image carrier while attracting the developer on a surface of the image carrier by the magnet, and
• wherein the rotary developing device further supports a foreign-substance collecting member on the revolution orbit on which the plurality of developing units are provided, and the foreign-substance collecting member magnetically collects a magnetic foreign substance on the foreign-substance receiving plate.