Tray swinging mechanism and device including the same

A tray swinging mechanism provided to a device having a main body, a tray, and a pickup roller, the tray being swingably supported by the main body with a first shaft, the tray extending from the first shaft toward a downstream side in a conveying direction which is perpendicular to the first shaft, the tray having a first surface on which document sheets are stacked and a second surface which is a surface opposite to the first surface, and the pickup roller being configured to contact the document sheets stacked on the tray to feed the document sheets toward the downstream side in the conveying direction,

• wherein the tray swinging mechanism comprises:
• a lever swingably supported by the main body with a second shaft extending parallelly to the first shaft at a position different from a position of the first shaft;
• and
• a driving source configured to generate a driving force to swing the lever,
• wherein the tray includes at least one cam surface formed on the second surface, the at least one cam surface being configured to contact a tip of the lever,
• wherein the at least one cam surface is formed such that, at every swinging movement of the lever by a particular constant angle, a moving amount of a tip of the tray is constant when the lever is swung by a particular angle, the at least one cam surface being arranged within a range where the pickup roller extends in an axial direction of the first shaft, and
• wherein the at least one cam surface includes:
• a parallel part parallel to the first surface of the tray;
• and
• a curved part extending to an upstream side from the parallel part continuously in the conveying direction, the curved part being spaced from the first surface farther toward the upstream side,
• the parallel part and the curved part configured to contact the tip of the lever.