Unit accommodation apparatus and image forming apparatus

An image forming apparatus comprising:

• an apparatus body having an opening;
• an image bearer unit to be installed into and removed from the apparatus body through the opening in a width direction of a recording medium, the width direction perpendicular to a recording medium conveyance direction in which the recording medium is conveyed;
• a transfer unit to be installed into and removed from the apparatus body through the opening in the width direction of the recording medium, the transfer unit to contact the image bearer unit to form a transfer nip between the image bearer unit and the transfer unit, the transfer nip through which the recording medium is conveyed;
• and
• a unit holder to hold the image bearer unit and the transfer unit,
• the unit holder including:
• a first positioner disposed opposite one lateral end of the image bearer unit and the transfer unit in the width direction of the recording medium, the one lateral end disposed opposite the opening, the first positioner detachably attached to the image bearer unit and the transfer unit, and
• a second positioner disposed opposite another lateral end of the image bearer unit and the transfer unit in the width direction of the recording medium, the second positioner to hold the image bearer unit and the transfer unit in a state in which the image bearer unit and the transfer unit are detachably attached to the second positioner in the width direction of the recording medium,
• the first positioner and the second positioner to secure a relative position of the image bearer unit relative to the transfer unit in a direction parallel to a hypothetical orthogonal plane perpendicular to the width direction of the recording medium.