Patent ID: 8509659

Claim:
An image forming apparatus, comprising: an image carrier configured to carry an electrostatic latent image on a surface thereof; and a developing device, including: a first developing roller and a second developing roller each configured to carry a toner layer formed on a surface thereof, wherein the electrostatic latent image on the surface of the image carrier is developed with the toner layer; a magnetic roller which has a fixedly arranged magnetic body and a rotatable sleeve roller containing the magnetic body therein, and which is provided to be opposed to the first and second developing rollers and is configured to carry and convey developer containing toner and carrier particles on an outer circumferential surface thereof to feed the toner in the developer to the first and second developing rollers; a pair of first spacing members each of which is provided coaxially with the first developing roller at each end of the first developing roller, wherein each of the first spacing members has a larger outer diameter than the first developing roller; a pair of second spacing members each of which is provided coaxially with the second developing roller at each end of the second developing roller, wherein each of the second spacing members has a larger outer diameter than the second developing roller; a pair of first retaining members each of which is configured to rotatably retain a rotation shaft of the sleeve roller and a rotation shaft of the first developing roller, with a prescribed constant clearance between the magnetic roller and the first developing roller; a pair of second retaining members each of which is configured to rotatably retain the rotation shaft of the sleeve roller and a rotation shaft of the second developing roller, wherein the second retaining members, along with the rotation shaft of the second developing roller, are swingable around the rotation shaft of the sleeve roller; a first biasing member configured to urge the first spacing members against the image carrier; and a second biasing member configured to urge the second spacing members against the image carrier.