Abstract: An image forming apparatus of the present invention includes a developing roller accommodating a magnet roller therein. The magnet roller includes a main pole forming a magnetic flux whose attenuation ratio is 40% or above in the direction normal to the developing roller. The axis A of the developer carrier, the axis B of the image carrier and the peak C of the magnetic force of the main pole in the above direction are positioned such that an angle between a line AB and a line AC is substantially zero degree.

Abstract: An image forming apparatus having a revolving type developing device including a plurality of monochrome developing members for developing a latent image formed on an image carrier with monochrome developer and a plurality of toner storing members for separately storing different toners. The apparatus includes a plurality of toner supplying members disposed in the revolving type developing device for supplying toner from one of the toner storing members to a corresponding one of the plurality of monochrome developing members. A plurality of density sensors are separately disposed in each of the monochrome developing members for sensing density of monochrome developer and generating a signal indicative of density of the monochrome developer. A light beam generating member is disposed inside the revolving type developing device for generating and irradiating a light beam with a density signal obtained by one of the density sensors.

Abstract: A developing device for image forming equipment capable of agitating and mixing a fresh toner and a developer sufficiently is disclosed. The device eliminates a change in image density among individual copies, irregularity in density corresponding to the spiral pitch of, for example, a toner transport screw, and irregularity in density in the front-and-rear direction (axial direction of a developing sleeve) ascribable to defective agitation. To replace or clean a desire part or parts built in a developing device, the device is divided into two such that the desired parts are freely accessible. This facilitates the cleaning and replacement of such parts.