Cover of image forming device

A device that uses sheets, the device comprising:

• a lower case;
• an upper case pivotably attached to the lower case so as to be pivotable about an imaginary pivot line with respect to the lower case, the upper case being formed with a sheet-supply port and a sheet-discharge port extending substantially in parallel with each other;
• a pin provided to one of the lower case and the upper case, the pin protruding in a direction substantially parallel with the imaginary pivot line and being axially centered on an imaginary circle that is centered on the imaginary pivot line;
• a resiliently deformable slide rib provided to another of the lower case and the upper case, the slide rib having an outwardly-curved surface eccentric with the imaginary circle, a one of the slide rib and the pin that is provided to the upper case following the imaginary circle when the upper case is pivoted open, so that the outwardly-curved surface and the pin pressingly slide against each other;
• and
• a sheet-supply tray disposed on the upper case at a position to sandwich the sheet-supply port between the sheet-supply tray and the sheet-discharge port, the sheet-supply tray having:
• an upper surface slanting downward toward the sheet-supply port;
• a pair of guides for guiding sheets stacked on the upper surface toward the sheet-supply port;
• and
• a pair of separation ribs provided one to each of the guides, the separation ribs together defining therebelow a sheet-supply pathway and thereabove a sheet-discharge pathway.