A device for estimating a size of an original document.

摘要

An original document size estimating device includes a first optical sensor and a second optical sensor operable to detect an original document placed on a specified position. The first optical sensor is positioned before the second optical sensor with respect to a forward direction. The first and second optical sensors are moved in both the forward direction and a backward direction opposite to the forward direction by a driver. The driver is controlled in such a manner as to forcibly move the first and second optical sensors in the forward direction further a predetermined additional distance when the first optical sensor generates absence signal and the second optical sensor generates presence signal, and return them after both generating absence signal to measure a length of the original document for size estimation. <IMAGE>