Document reading device and image forming apparatus

A document reading device comprising:

• an image capturing member that captures an image of a document;
• a placement portion that is disposed below the image capturing member and that has a boundary line between a plurality of surfaces at a position at which the boundary line is covered by the document when the document has a maximum size that the image capturing member is capable of imaging and the document is placed on the placement portion;
• and
• a document reading member that reads the document that is placed on the placement portion, wherein the plurality of surfaces comprises a cover of the document reading member and a plate of the placement portion.