DOCUMENT DETECTING DEVICE, DOCUMENT DETECTING METHOD AND IMAGE READING DEVICE

Certain embodiments provide a document detecting device, including: a plate having an upper surface on which a document is placed; an imaging device that includes the upper surface in a photographing visual field range; and a controller that detects any one or more of a position, an angle, and a size of the document on the upper surface according to an image by the imaging device and fixed-size information of the document stored in advance.