Imaging unit and latent image carrier unit

An image forming unit comprising: a latent image carrier unit and a developing unit which are detachably mounted to each other with the latent image carrier unit has a latent image carrier, and wherein the developing unit comprises a developing roller; and a pressing device which is operable in the sequence of at least one motion when the latent image carrier unit is mounted on the developing unit namely a mounting motion, and a drive movement in the image forming unit so as to press the developing roller of the developing unit to the latent image carrier of the latent image bearing unit, wherein the pressing device comprises a Hebeloffnungs- and closing mechanism, which is present in the latent image bearing unit a rotation mechanism, which is present in the developing unit, and is driven by a driving force which is derived from a main body of an image forming apparatus, and a rotating mechanism of the latent image carrier, which by a driving force is driven, which is derived from a main body of the image forming apparatus, and wherein the pressing device comprises a projection which is present in the latent image bearing unit, and a projection, and with which exists in the developing unit to the projection of the latent image carrier unit is engageable, which is generated by a rotational force of the latent image carrier rotating mechanism a force to the developing unit to press on the latent image carrier.