Cartridge unit and image forming apparatus

A cartridge unit configured to be detachably attached to an apparatus body of an image forming apparatus, the cartridge unit comprising:

• a first unit including
• a photosensitive drum configured to bear a developer image,
• a frame rotatably supporting the photosensitive drum,
• a developing roller configured to develop an electrostatic latent image formed on a surface of the photosensitive drum, and including a first end in an axis direction and a second end opposite to the first end in the axis direction, and
• a driving-force transmission portion disposed on a side of the first end of the developing roller and configured to transmit driving force transmitted from the image forming apparatus, to the developing roller;
• and
• a second unit including a memory disposed on the side of the first end configured to store information, and a holder holding the memory, the second unit being detachably attached to the first unit and configured to accommodate developer,
• wherein the frame includes
• a bottom surface that extends in the axis direction, and
• a first side wall that extends from the bottom surface in an intersecting direction that intersects the axis direction, and that is positioned, in the axis direction, inside with respect to the driving-force transmission portion and outside with respect to the second unit attached to the first unit, and
• wherein the memory is disposed outside with respect to the first side wall in the axis direction in a state where the second unit is attached to the first unit.