Among original document reading devices, such as copy machines and the like, are automatic document feeders for feeding, one sheet at a time, a plurality of sheets of a document that are stacked and arranged in a document setting unit, and sequentially reading, by a scanner, images of the document.
However, in cases where a document with a plurality of sets is copied using an original document reading device of a type as described above, when it is desired to vary printing modes (for example, number of printed sheets) for each set, the repetitive task of arranging the document in the document setting unit one set at a time, and configuring the printing mode for each set by an operation of an operations unit, before starting a copying operation, must be performed, which is cumbersome.
Consequently, according to the prior art, if a separator sheet is interposed between each set in the document with the plurality of sets before reading, even in cases where a document with a plurality of sets is stacked and arranged in the document setting unit, switching of sets can be detected, and the printing mode for each set can be varied.
However, in configurations such as the abovementioned prior art, the separator sheets for interposing between each set in the document with the plurality of sets have to be expressly prepared, and, additionally, the task of interposing the prepared separator sheets between each set of the document with the plurality of sets is cumbersome.
The present invention was made in view of this background and has as an object the provision of an original document reading device that can more easily detect switching of sets in a document with a plurality of sets.