Feeding device and image forming apparatus

1. A feeding device comprising:

a first feeding unit configured to feed a first recording medium;

a second feeding unit located below the first feeding unit and configured to feed a second recording medium differing from the first recording medium; and

a fixing structure configured to take a first posture or a second posture differing from the first posture, the fixing structure fixing the second feeding unit to the first feeding unit when the fixing structure is in the first posture, wherein

the second feeding unit includes an insertion hole at an upper end thereof and a first frame member at the upper end thereof,

the fixing structure includes a cylindrical member inserted through the insertion hole and a first engagement member inserted through the insertion hole,

in a state where the cylindrical member and the first engagement member are inserted through the insertion hole, the first engagement member engages with the first frame member,

through rotation of the fixing structure about the cylindrical member, a posture of the fixing structure is changed between the first posture and the second posture,

the fixing structure fixes the second feeding unit to the first feeding unit by fixing the first frame member of the second feeding unit to a second frame member of the first feeding unit, and

when the fixing structure is in the second posture, the fixing structure releases linkage between the second feeding unit and the first feeding unit.

2. The feeding device according to claim 1 , wherein

the fixing structure further includes a fixing member that fixes the second feeding unit to the first feeding unit,

the fixing member is connected with the cylindrical member,

the fixing member includes a first protrusion and a second protrusion differing from the first protrusion,

the frame member of the first feeding unit is a second frame member located at a lower end of the first feeding unit,

the frame member of the second feeding unit is a third frame member located at the upper end of the second feeding unit, the third frame member differing from the first frame member,

when the fixing structure is in the first posture, the first protrusion engages with the second frame member and the second protrusion engages with the third frame member, and

when the fixing structure is in the second posture, the first protrusion is disengaged from the second frame member and the second protrusion is disengaged from the third frame member.

3. The feeding device according to claim 1 , wherein

the second feeding unit further includes a detector that detects the fixing structure taking the first posture.

4. A feeding device comprising:

a first feeding unit configured to feed a first recording medium;

a second feeding unit located below the first feeding unit and configured to feed a second recording medium differing from the first recording medium; and

a fixing structure configured to take a first posture or a second posture differing from the first posture, the fixing structure fixing the second feeding unit to the first feeding unit when the fixing structure is in the first posture, wherein

the fixing structure fixes the second feeding unit to the first feeding unit by fixing a frame member of the second feeding unit to a frame member of the first feeding unit,

when the fixing structure is in the second posture, the fixing structure releases linkage between the second feeding unit and the first feeding unit,

the second feeding unit further includes a feeding cassette in which the second recording medium is stacked,

the feeding cassette is attachable to and detachable from the second feeding unit,

the fixing structure further includes a protruding member,

when the fixing structure is in the first posture, the protruding member allows attachment of the feeding cassette to the second feeding unit, and

when the fixing structure is in the second posture, the second protruding member obstructs the feeding cassette from attaching to the second feeding unit.

5. An image forming apparatus comprising:

an image forming device configured to form an image on a recording medium, the recording medium being either a first recording medium or a second recording medium differing from the first recording medium;

a first feeding unit configured to feed the first recording medium to the image forming device;

a second feeding unit located below the first feeding unit and configured to feed the second recording medium to the image forming device; and

a fixing structure configured to take a first posture or a second posture differing from the first posture, the fixing structure fixing the second feeding unit to the first feeding unit when the fixing structure is in the first posture, wherein

the fixing structure fixes the second feeding unit to the first feeding unit by fixing a frame member of the second feeding unit to a frame member of the first feeding unit, and

when the fixing structure is in the second posture, the fixing structure releases linkage between the second feeding unit and the first feeding unit,

the image forming apparatus further comprises:

a detector configured to detect the fixing structure taking the first posture; and

a controller configured to control operation of the image forming apparatus, and

the controller gives a notification of a result of detection by the detector.

6. The image forming apparatus according to claim 5 ,

wherein

when the detector does not detect the fixing structure taking the first posture, the controller forbids operation of the image forming device.