An in-line image forming apparatus that includes a plurality of photosensitive drums of respective colors arranged in line and forms a color image by successively superposing toner images of the respective colors on photosensitive drums onto each other is put into practical use, as an image forming apparatus of a plurality of colors or full colors using an electrophotographic method.
PTL 1 suggests a configuration in which a plurality of photosensitive drums are arranged below an intermediate transfer member and a first transfer surface of the intermediate transfer member is arranged in an inclined manner to decrease the distance of the intermediate transfer member from a first transfer portion to a second transfer portion and hence to decrease a period of time until a transfer material is output from an image forming apparatus. Also, since the intermediate transfer member is arranged in an inclined manner, the dimensions in the lateral direction and height direction of the image forming apparatus are decreased in a balanced manner and hence the space in the image forming apparatus is efficiently used.
A residual toner that is not second-transferred from the intermediate transfer member to a transfer material and remains on the intermediate transfer member is removed from the intermediate transfer member by a cleaning device. A conventionally known cleaning device is a configuration that scrapes the toner on the intermediate transfer member by a cleaning blade serving as a cleaning member that is pressed to the intermediate transfer member. The scraped toner is removed into a container that is provided in the image forming apparatus.
PTL 2 discloses a configuration in which an intermediate transfer member is integrally formed with a cleaning device as a transfer unit and the transfer unit is detachably mountable on an apparatus body. Further, PTL 3 discloses a configuration in which a container is attachable to and detachable from a cleaning device and the container is individually detachably mountable on an image forming apparatus.