The present invention relates to a developing
cartridge detachably mounted in an image forming apparatus, the developing
cartridge comprising: a developing housing for accommodating carbon
powder; a developing roller rotatably disposed in the developing housing; the counting
assembly is arranged at one end of the developing shell and is used for interacting with the detection component; the power source is used for outputting power to the counting
assembly; the triggering piece is provided with an acting position and a non-acting position; at the acting position, the movement of the triggering piece is limited, the
power output by the power source is limited by the triggering piece, and the counting
assembly does not interact with the detection component; at the non-acting position, the trigger piece can move relative to the developing shell, the trigger piece does not limit the
power output by the power source, the trigger piece moves from the acting position to the non-acting position under the action of the
power output by the power source, and the counting assembly interacts with the detection part; according to the design, the structure of the developing box can be simplified, the production cost can be reduced, the fluidity of the carbon
powder cannot be influenced, and meanwhile, the selectable range of the material of the triggering piece is larger.