A method of reducing a time for switching a gate line driving signal of display device having plural gate lines from a level that is less than a full gate-on level to the gate-on level is disclosed. The method may include: during a gate line pre-charging period of a respective gate line, causing the gate line driving signal to be at the full gate-on level; during a corresponding gate line main-charging period that follows the pre-charging period, causing the gate line driving signal of to be at the full gate-on level; and during an interposed period that is interposed between the gate line pre-charging period and its corresponding gate line main-charging period, causing the gate line driving signal to be at an intermediate level that is between the full gate-on level and an opposed gate-off level.