Abstract: An image forming apparatus of the type forming a toner image on a photoconductive drum or similar image carrier, transferring it to a paper or similar transfer medium via an intermediate transfer body, e.g., belt, and fixing it on the medium by a fixing device is disclosed. Just after the transfer of a toner image of the last color which is to lie over the other toner images on the intermediate transfer belt, the peripheral speed of the belt is switched to a comparatively low speed matching a fixing and paper transport speed. At this instant, the belt is moved away from the drum. The length of the transfer medium and the distance between a paper transfer position and a fixing position is compared. For a relatively short transfer medium, the peripheral speed of the belt is not switched to the low speed.

Abstract: An image forming apparatus of the type capable of forming a plurality of images in separate areas of an intermediate transfer body is disclosed. When a paper or similar recording medium to which a toner image formed on the intermediate transfer body should be transferred is absent, the transfer of a toner image from the image carrier to the intermediate transfer body is interrupted. At the same time, toner left on the intermediate transfer body is removed by a particular method different from a usual method and capable of enhancing a cleaning ability. The apparatus is therefore capable of fully removing the toner and thereby obviating defective images.

Abstract: In an image forming apparatus using dry toner, a toner replenishing device includes cleaning means for cleaning the sensing surface of remaining toner sensing means. The cleaning means is driven by the same drive source as agitating means for agitating the toner. To clean the sensing surface, the cleaning means is driven in a particular manner different from a manner for usual toner replenishment. While the cleaning means cleans the sensing surface, the output signal of the remaining toner sensing means is detected. The device achieves highly accurate toner concentration control and toner end detection at the same time.