Developing cartridge having coupling and developing roller

A cartridge comprising:

• a developing roller rotatable about a developing axis extending in the first direction;
• a housing configured to accommodate developing material therein, the housing having a first end portion and a second end portion separated from the first end portion in the first direction;
• a coupling rotatable about the coupling axis extending in the first direction, the coupling being positioned at the first end portion of the housing;
• an electrode electrically connected to the developing roller, the electrode being positioned at the second end portion of the housing;
• a first gear rotatable about a first gear axis extending in the first direction in association with rotation of the coupling, the first gear being positioned at the first end portion of the housing;
• a pinion gear rotatable about a pinion gear axis extending in the first direction in association with rotation of the first gear, the pinion gear being positioned at the second end portion of the housing;
• a rack gear meshing with the pinion gear, the rack gear being positioned at the second end portion of the housing, the rack gear movable in association with rotation of the pinion gear;
• and
• a plate movable relative to the electrode in association with movement of the rack gear.