Developing cartridge including cam movable relative to casing between first position and second position

A developing cartridge attachable to a drum cartridge including a photosensitive drum, the developing cartridge comprising:

• a developing roller rotatable about a first axis extending in a first direction, the developing roller being configured to be positioned at a contact position where the developing roller is in contact with the photosensitive drum, and being also configured to be positioned at a separated position where the developing roller is separated from the photosensitive drum;
• a casing configured to accommodate therein developing agent;
• and
• a cam movable relative to the casing between a first position and a second position in the first direction, the second position being a position further in a direction from one side toward another side in the first direction than the first position, the cam having a sloped surface sloping with respect to the first direction;
• wherein in a state of attachment of the developing cartridge to the drum cartridge, the developing roller is positioned at the contact position at the first position of the cam, a portion of the developing cartridge is in contact with the drum cartridge and functions as a pivot center so that the casing and the developing roller are pivotally moved about the pivot center when the cam is moved from the first position to the second position, and the developing roller is positioned at the separated position at the second position of the cam.