Patent attributes
In fixing a standing board to a main board, the standing board is held by a first and a second fixing holder and fixed at right angles to the main board. The first and the second fixing holders are identical, being formed of metal plates having the same shape. The first fixing holder holds one of two opposite edges of the standing board with a side board thereof extending from an edge of a back board face in a direction perpendicular thereto such that the back board face and one face of the standing board face each other and are substantially parallel to each other. The second fixing holder holds the other one of the two opposite edges of the standing board with a side board thereof extending from an edge of a back board face in a direction perpendicular thereto such that the back board face and the other face of the standing board face each other and are substantially parallel to each other.