Image forming device and tray assembly thereof

An image forming device comprising:

• a casing comprising an upper side and a lateral side adjacent to the upper side, a medium gateway opening being formed on the lateral side;
• and
• a tray assembly comprising:
• a tray body pivoted to the casing and pivotally switchable relative to the casing between a first used position and a first folded position, the tray body covering the upper side of the casing when the tray body is pivoted to the first folded position, a side of the tray body being adjacent to the medium gateway opening when the tray body is pivoted to the first used position;
• a cover body pivoted to the casing and pivotally switchable relative to the casing between a second used position and a second folded position, the cover body covering the lateral side of the casing to conceal the medium gateway opening when the cover body is pivoted to the second folded position, the cover body revealing the medium gateway opening when the cover body is pivoted to the second used position;
• and
• a resilient component connected to the cover body for biasing the cover body to pivot to the second folded position;
• wherein the tray body pushes the cover body to drive the cover body to pivot relative to the casing from the second folded position to the second used position in a first pivoting direction when the tray body pivots relative to the casing from the first folded position to the first used position in the first pivoting direction, and the resilient component drives the cover body to pivot relative to the casing from the second used position to the second folded position in a second pivoting direction opposite to the first pivoting direction when the tray body pivots relative to the casing from the first used position to the first folded position in the second pivoting direction;
• wherein a first guiding structure is formed on the cover body, at least one second guiding structure is formed on the tray body, the tray body drives the cover body to leave away from the second folded position by cooperation of the at least one second guiding structure and the first guiding structure during a period that the tray body pivots from the first folded position to the first used position;
• wherein the at least one second guiding structure is a slanted rib, and the first guiding structure is a slanted surface structure with an arc edge chamfer.