An electronic device comprising: a housing structure comprising a front face and a rear face facing away from the front face; a plate comprising a first face and a second face facing away from the first face and configured to be pivotally movable around a first axis between a closed state and an open state with respect to the rear face, the second face facing at least a partial region of the rear face in the closed state, and the second face forming an angle with at least the partial region of the rear face in the open state; and a hinge structure (15, 100) configured to pivotably couple the plate to the housing, wherein the hinge structure (15, 100) comprises: a first shaft comprising a first straight-toothed spur gear rotatable around a second axis parallel to the first axis; a second shaft comprising a second straight-toothed spur gear rotatable around a third axis parallel to the first axis; a third straight-toothed spur gear rotatable in engagement with the first spur gear; a fourth straight-toothed spur gear rotatable in engagement with the third spur gear and the second spur gear; a first guide structure fixed to the housing structure, the first guide structure comprising a first curved opening comprising a first straight-toothed inner gear; and a second guide structure fixed to the plate, the second guide structure comprising a second curved opening comprising a second straight-toothed inner gear, and wherein the first inner gear is engaged with the first spur gear, but is not engaged with the second spur gear, the third spur gear and the fourth spur gear, the second inner gear is engaged with the second spur gear, but is not engaged with the first spur gear, the third spur gear and the fourth spur gear, and each of the first guide structure and the second guide structure is rotatable around the first axis. a housing structure comprising a front face and a rear face facing away from the front face; a plate comprising a first face and a second face facing away from the first face and configured to be pivotally movable around a first axis between a closed state and an open state with respect to the rear face, the second face facing at least a partial region of the rear face in the closed state, and the second face forming an angle with at least the partial region of the rear face in the open state; and a hinge structure (15, 100) configured to pivotably couple the plate to the housing, wherein the hinge structure (15, 100) comprises: a first shaft comprising a first straight-toothed spur gear rotatable around a second axis parallel to the first axis; a second shaft comprising a second straight-toothed spur gear rotatable around a third axis parallel to the first axis; a third straight-toothed spur gear rotatable in engagement with the first spur gear; a fourth straight-toothed spur gear rotatable in engagement with the third spur gear and the second spur gear; a first guide structure fixed to the housing structure, the first guide structure comprising a first curved opening comprising a first straight-toothed inner gear; and a second guide structure fixed to the plate, the second guide structure comprising a second curved opening comprising a second straight-toothed inner gear, and wherein the first inner gear is engaged with the first spur gear, but is not engaged with the second spur gear, the third spur gear and the fourth spur gear, the second inner gear is engaged with the second spur gear, but is not engaged with the first spur gear, the third spur gear and the fourth spur gear, and a first shaft comprising a first straight-toothed spur gear rotatable around a second axis parallel to the first axis; a second shaft comprising a second straight-toothed spur gear rotatable around a third axis parallel to the first axis; a third straight-toothed spur gear rotatable in engagement with the first spur gear; a fourth straight-toothed spur gear rotatable in engagement with the third spur gear and the second spur gear; a first guide structure fixed to the housing structure, the first guide structure comprising a first curved opening comprising a first straight-toothed inner gear; and a second guide structure fixed to the plate, the second guide structure comprising a second curved opening comprising a second straight-toothed inner gear, and wherein the first inner gear is engaged with the first spur gear, but is not engaged with the second spur gear, the third spur gear and the fourth spur gear, the second inner gear is engaged with the second spur gear, but is not engaged with the first spur gear, the third spur gear and the fourth spur gear, and each of the first guide structure and the second guide structure is rotatable around the first axis.