1. A character input apparatus for a keyboard on which a key picture surface is displayed, said apparatus comprising: detection means for detecting a designated key position based on input coordinates where a designated character key pattern is depicted on a displayed keyboard; identification means for recognizing an input pattern which is superimposed on said designated key pattern depicted in the detected key position on said displayed keyboard and for identifying a pattern having a similar shape to said input pattern from among a plurality of predetermined patterns having different shapes, respectively; code generation means for generating a specific code based on the designated key position detected by said detection means and the input pattern identified by said identification means; and input means for inputting a pattern constituted by said specific code at a plurality of coordinates corresponding to those input on the display keyboard.