A liquid crystal lens unit is provided as follows. Lower plate electrodes are positioned on a first substrate. The lower plate electrodes are extended in a first direction and spaced apart from each other in a second direction crossing the first direction. An upper plate electrode is positioned on the lower plate electrodes. A second substrate is positioned on the upper plate electrode. A liquid crystal layer is positioned between the lower plate electrodes and the upper electrode. A first voltage is applied to at least two outermost lower plate electrodes and then, a second voltage lower than the first voltage is applied to at least two second outermost lower plate electrodes.