An image reading device of the type in which a display panel is laid over a document table and an image on an original document is input through the display panel. In the image reading device, the display panel is a liquid crystal panel of the transmission type in which liquid crystal/polymer composite material is sandwiched by electrodes, and at least one of the electrodes sandwiching the liquid crystal/polymer composite material consists of a plurality of divided electrodes. Further, a gap between the adjacent divided electrodes is shorter than a minimum resolution distance in a location of the display panel of the image reading device. Alternatively, an electrode layer may be provided covering the gap between the adjacent divided electrodes in a state that an insulating layer is layered between the electrode layer and the gap. The ends of the divided electrodes may overlap with each other, with an insulating layer being layered therebetween. In this case, no gap is present between the adjacent divided electrodes. A distance t between the display panel and the document table is preferably 3 mm.ltoreq.t.ltoreq.30 mm.