Patent ID: 7516955

Claim:
A paper feed tray comprising: a tray unit configured to accommodate a stack of recording mediums; a first aligning unit slidable in a first direction and that is configured to perform an alignment of the stack of the recording mediums in the tray unit in the first direction; a second aligning unit slidable in a second direction that is orthogonal to the first direction and that is configured to perform an alignment of the stack of the recording media in the tray unit in the second direction; a first movable member including a first corrugated portion, and configured to pivot with respect to the tray unit according to sliding motion of the first aligning unit; a second movable member including a second corrugated portion, and configured to pivot with respect to the tray unit according to sliding motion of the second aligning unit, the first corrugated portion and the second corrugated portion making a composite corrugated portion such that the first corrugated portion and the second corrugated portion overlap as seen along an axis of rotation of the first movable member such that the first corrugated portion outer diameter is congruent to the second corrugated portion outer diameter, and the composite corrugated portion is defined by both movements of the first movable member and the second movable member, which are moved by both sliding movements of the first aligning unit and sliding movements of the second aligning unit, respectively, so that the composite corrugated portion represents a size of the stack of recording mediums; and a detecting unit that has a plurality of actuatable portions configured to be selectively actuated by the composite corrugated portion so that the detecting unit detects the size of the stack of recording mediums.