Door opening and closing assisting device and method

A door opening and closing assisting device for assisting a closing operation of a door which is connected to a main body of an apparatus through a hinge mechanism to open or close an aperture part formed in the main body of the apparatus comprising:

• a lever member which is swung in cooperation with an opening and closing operation of the door;
• a first spring member for generating an urging force which is elastically deformed by a swing motion of the lever member when the door is swung in an open direction and which urges the door by an elastic return force in a closing direction through the lever member;
• and
• a switching mechanism which mechanically connects the lever member to the first spring member in response to the door being between a completely (closed position and a half-opened position where the door is swung by a prescribed angle in an open direction from the completely closed position and which releases the mechanical connection between the lever member and the first spring member maintaining the first spring member in a state where the first spring member is forcibly urged and elastically deformed in response to the door being at a further opened position from the half-opened position;
• wherein the lever member, the first spring member and the switching mechanism are arranged on one of the door and the main body of the apparatus.