Document reading device and image forming apparatus

A document reading device comprising:

• an imaging unit that images a document;
• a placing portion that includes a first placing portion and a second placing portion and that has a placing surface on which the document is placed, the placing surface being formed by the first placing portion and the second placing portion, wherein an end portion of the first placing portion adjacent to the second placing portion extends toward the second placing portion beyond an end portion of the second placing portion adjacent to the first placing portion;
• a detector that detects an edge of the document that is placed on the placing surface by using a color difference or a luminance difference between the placing surface and the document;
• a loading portion that is disposed below the placing surface and that enables a plurality of the documents to be loaded thereon;
• and a reading member that reads a document that is placed on the loading portion while transporting the document, wherein the reading member transports the document that is placed on the loading portion via an opening that is adjacent to the loading portion in a direction that intersects a vertical direction, and wherein the first placing portion is a covering that covers an upper surface of the reading member.