US Patent 7813666 Process unit, image formation apparatus, and developing cartridge

When a developing cartridge is accommodated in an accommodating section of a process unit casing, an electrode of the developing cartridge for inputting a bias to a developer carrier enters an engagement portion of the process unit casing to be engaged with and fixed to the engagement portion. A joint member joins the electrode to a developing cartridge casing so that the developing cartridge casing is movable relative to the process unit casing in a state in which the electrode is engaged with and fixed to the engagement portion.