DEVELOPING CARTRIDGE

PROBLEM TO BE SOLVED: To provide a developing cartridge capable of achieving miniaturization thereof by reducing the moving range of a detecting protrusion thereof. SOLUTION: The developing cartridge includes: a rotating body 81 rotatably provided in a housing; the detection protrusion 81C formed at a position deviated from the rotational center of the rotating body 81 while protruding from the housing; a transmission gear 82 for transmitting a driving force input from the outside to the rotating body 81; an elastic body (torsion coil spring 83) connecting between the rotating body 81 and the transmission gear 82; and an engagement part (slide groove 74) disposed in the housing, and engaging with the rotating body 81. The engagement part is configured to engage with the rotating body 81 by an engaging force by which the transmission gear 82 can rotate relatively with the rotating body 81 before prescribed deformation of the elastic body, and by which the transmission gear 82 and the rotating body 81 can integrally rotate after the prescribed deformation of the elastic body. COPYRIGHT: (C)2010,JPO&INPIT