Process unit positioning device and image forming apparatus including the same

An image forming apparatus, comprising:

• an apparatus main body;
• process units individually comprising photosensitive drums corresponding to different colors of toner, which are arranged in parallel substantially in a horizontal direction so as to be detachable/attachable from/to the apparatus main body;
• developing units provided adjacent to the respective process units so as to be detachable/attachable from/to the apparatus main body, for developing electrostatic latent images, which are formed on the respective photosensitive drums, with the respective colors of toner;
• an intermediate transfer belt provided adjacent to top portions of the respective process units, for transferring and superimposing toner images formed on the respective photosensitive drums while traveling in abutment with peripheral surfaces of the respective photosensitive drums in the same direction;
• a process unit positioning device for performing mutual positioning of the respective process units with respect to the apparatus main body;
• cleaning devices provided, respectively, in the respective process units, for collecting the toner remaining on the respective photosensitive drums after the transferring of the toner images;
• and
• a waste toner conveying device for conveying the toner, which is collected by the respective cleaning devices and discharged therefrom, to a collection container, wherein:
• the process unit positioning device holds a positioning plate including a positioning portion so as to be able to rock while being supported by the apparatus main body so as to be able to pivot, and is allowed to be switched over between a positioning posture for performing positioning of the respective process units on one end side of the photosensitive drum in an axial direction thereof with respect to the apparatus main body and a releasing posture for releasing the positioning of the respective process units on the one end side with respect to the apparatus main body;
• the waste toner conveying device is supported by the apparatus main body so as to be able to pivot, and is allowed to be switched over between a collecting posture for collecting and conveying the toner, which is discharged from the respective cleaning devices and an opened posture in which the waste toner conveying device is opened from an upper side of a front surface of the apparatus main body;
• the collection container is arbitrarily detachable/attachable in the positioning posture of the process unit positioning device and in the collecting posture of the waste toner conveying device;
• the respective process units are arbitrarily detachable/attachable in the opened posture of the waste toner conveying device and in the releasing posture of the process unit positioning device;
• the waste toner conveying device has
• a plurality of connection ports attachable to/detachable from respective waste toner outlets of the process units, and
• a dischargable outlet through which the toner discharged from the cleaning devices and transported into the waste toner conveying device via the respective waste toner outlets and the respective connection ports is discharged into the collection container;
• and
• the collection container is attachable/detachable with the respective waste toner outlets of the process units connected to the respective connection ports of the waste toner conveying device.