Image forming system, image forming apparatus and image reading apparatus

An image forming system comprising an image forming apparatus and an image reading apparatus, wherein

• the image forming apparatus includes:
• a first casing including a top plate having a first opening and a second opening;
• and
• a fixing member disposed below the top plate, having a first projecting part and a second projecting part and operated such that the first projecting part is protruded and retracted through the first opening and the second projecting part is protruded and retracted through the second opening,
• the image reading apparatus includes:
• a second casing placed on the top plate of the first casing;
• a moving frame supporting an optical unit introducing reflected light reflected on a document to an imaging element, and being movable inside the second casing;
• a lock member which is engaged with the moving frame to restrict movement of the moving frame, and when pushed up by the first projecting part protruding through the first opening, is disengaged from the moving frame to release restriction of the movement of the moving frame;
• and
• a third opening formed in a bottom plate of the second casing and into which the second projecting part protruding through the second opening is inserted.