Image forming apparatus including developing device supporting structure having guide groove

An image forming apparatus comprising:

• a main casing having an opening;
• an opening-closing member configured to move between an open position for opening the opening and a closed position for closing the opening;
• a plurality of developing devices detachably attached to the main casing through the opening, each of the plurality of developing devices including a developing roller, the developing roller rotating around a shaft extending a first direction, the plurality of developing devices being arranged in a second direction perpendicular to the first direction;
• a plurality of photosensitive drums, respective developing devices forming toner images on respective photosensitive drums;
• an intermediate transfer belt configured to transfer the toner images formed on respective photosensitive drums to a sheet;
• a developing device supporting structure configured to support the plurality of developing devices and configured to move through the opening in the second direction between an inner position inside the main casing and an outer position outside the main casing such that the plurality of developing devices is attachable to and detachable from the developing device supporting structure in the outer position;
• and
• a developing device moving mechanism extending in the second direction, a plurality of spring members configured to press the plurality of developing devices being arranged in the second direction, the developing device moving mechanism being configured to move between a first position and a second position with respect to the main casing and configured such that the developing device moving mechanism in the first position presses the plurality of developing devices toward the intermediate transfer belt via the plurality of spring members,
• wherein
• in response to a movement of the opening-closing member from the closed position to the open position, the developing device moving mechanism moves from the first position to the second position which is located downstream in a direction in which the developing device supporting structure moves from the inner position to the outer position and is away from the intermediate transfer belt,
• in response to a movement of the opening-closing member from the open position to the closed position, the developing device moving mechanism moves to the first position and presses the plurality of developing devices toward the intermediate transfer belt via the plurality of spring members,
• in response to a movement of the opening-closing member from the closed position to the open position, the developing device moving mechanism moves to the second position and releases the pressure of the plurality of developing devices toward the intermediate transfer belt via the plurality of spring members,
• the developing device moving mechanism in the second position does not contact the opening-closing member, and
• the developing device moving mechanism in the first position contacts the opening-closing member.