Letter input method using touchscreen

A letter input method using a touch screen, comprising:

• a soft keyboard displaying step for distinguishably displaying an input window region and a soft keyboard region on the touch screen;
• a key button displaying step for displaying key buttons on which some letters corresponding to an action of a user are arranged, in the soft keyboard region;
• an action recognizing step for recognizing an input action of the user at the key buttons;
• and
• a letter inputting step for inputting a letter corresponding to any one of a touch action, a basic slip action and a consecutive slip action, or a combination thereof, in the recognized input action,
• wherein in the letter inputting step, the touch action includes an action of pressing and then releasing a key button in the soft keyboard region, an action of pressing and then releasing a key button in the soft keyboard region several times within a critical time, or an action of pressing a key button in the soft keyboard region over the critical time,
• wherein in the letter inputting step, the basic slip action includes an action of slipping at a key button in the soft keyboard region in a first direction, in a second direction opposite to the first direction, in a third direction perpendicular to the second direction or in a fourth direction opposite to the third direction, and
• wherein in the letter inputting step, the consecutive slip action includes a first consecutive slip action or an nth (n is a natural number of 2 or above) consecutive slip action for consecutively slipping at the key button in any one of three directions, which excludes the slip direction of the former basic slip action among the first to fourth directions, in a state where the key button is continuously pressed, after the basic slip action is completed, and the nth consecutive slip action includes an action of consecutively slipping at the key button in any one of three directions, which excludes the slip direction of the n−1th consecutive slip action among the first to fourth directions, in a state where the key button is continuously pressed, after the n−1th consecutive slip action is completed.