Patent ID: 7721968

Claim:
A method for disambiguating from among a plurality of characters associated with each of a plurality of buttons composing at least a portion of a 12-button keypad on a mobile phone, comprising: sampling mobile phone tilt along two perpendicular axes that are parallel to a front face of the mobile phone, the front face of the mobile phone having at least one of a display and the 12-button keypad, the sampling occurring at a sampling rate of at least 20 Hz; maintaining a sample stack indicative of continuously updated past mobile phone tilt samples corresponding to the mobile phone; detecting that a user has activated a button by depressing or releasing one of the plurality of buttons in the 12-button keypad on the mobile phone; calculating a tilt state of the mobile phone when the button is activated, by comparing a most recent mobile phone tilt to a floating origin that is set by continuously monitoring the sample stack to identify when a tilt gesture begins, the beginning of the tilt gesture corresponding to the floating origin; upon determining that the tilt state of the mobile phone falls within a first mobile phone tilt threshold, identifying a numeral associated with the button; upon determining that the tilt state of the mobile phone falls within a second mobile phone tilt threshold, identifying a first character associated with the button; upon determining that the tilt state of the mobile phone falls within a third mobile phone tilt threshold, identifying a second character associated with the button; upon determining that the tilt state of the mobile phone falls within a fourth mobile phone tilt threshold, identifying a third character associated with the button; displaying the identified character on the display; and repeating the steps of sampling, maintaining, detecting, calculating, and at least one of the determining steps for each button activated by the user in entering a string of characters.