Hinge structure

A hinge structure, comprising:

• a first board comprising a first board body and a first connecting portion provided on at least one side thereof, wherein the first connecting portion extends from a portion of an edge of the first board body and bends to define a first groove;
• a second board comprising a second board body and a second connecting portion provided on at least one side thereof, wherein the second connecting portion extends from a portion of an edge of the second board body and bends to define a second groove;
• and
• a hinge shaft disposed to extend through the first groove of the first connecting portion and the second groove of the second connecting portion;
• wherein a maximum rotation angle between the first connecting portion and the second connecting portion is 90°, and throughout an original state in which the first connecting portion and the second connecting portion are not rotated relative to each other, a limiting state in which they are rotated 90° relative to each other, and an intermediate transition state between the original state and the limiting state, a first opening of the first groove of the first connecting portion and a second opening of the second groove of the second connecting portion always face different directions, and
• wherein, in the limiting state of the first connecting portion and the second connecting portion, the first board body is perpendicular to the second board body, a portion of an edge of the first board body abuts against the second connecting portion, and a portion of an edge of the second board body abuts against the first connecting portion.