22. The character input apparatus of claim 18 , wherein the touch screen enlarges and displays the characters of the key region where the press event occurs in at least two key regions of a pop-up window type under the control of the controller.
18. The character input apparatus of claim 16 , wherein the controller determines whether a key region indicated according to distance and direction of the drag event is the same as one of the key regions where the characters of the key region where the press event occurs are displayed, highlights the indicated key region if it is determined that the key region is the same as one of the key regions, and outputs a character of the key region where the release event occurs onto a predetermined input editor window of the touch screen if the release event occurs in the highlighted key region.