A method of controlling the operation of a mobile terminal, the method comprising: switching the mobile terminal to a lock mode; displaying, on a display module of the mobile terminal, a button or icon as a stereoscopic three-dimensional image using a disparity between a left-eye image and a right-eye image for releasing the mobile terminal from the lock mode; receiving, from a user input unit implemented as a capacitive touch pad, touch inputs or touch-and-drag inputs entered by a user on the displayed button or icon for releasing the mobile terminal from the lock mode; determining whether the user who has entered the touch inputs or the touch-and-drag inputs is already registered in the mobile terminal; correcting a touch-sensing area on the display module if the user is yet to be registered in the mobile terminal; and releasing the mobile terminal from the lock mode; wherein the touch-sensing area is an area within which the presence and location of a touch for selecting the stereoscopic three-dimensional image is sensed; and the determining step further comprising: obtaining capacitance measurements corresponding to each touch input or touch-and-drag input detected in the touch-sensing area of the displayed button or icon; comparing the capacitance measurements with a registered capacitance value; and determining based on the results of the comparison whether the user is registered; and the correcting step further comprising: correcting the touch-sensing area by automatically setting, as a background task, the touch-sensing area to a new touch-sensing area based on an average of the capacitance measurements according to the location of the touch inputs which are received within a first area of, a second area of, or a third area of the stereoscopic three-dimensional image and the right-eye image being displayed in the first area, the left-eye image being displayed in the second area, and the third area being an overlapping area of the left-eye and right-eye images. switching the mobile terminal to a lock mode; displaying, on a display module of the mobile terminal, a button or icon as a stereoscopic three-dimensional image using a disparity between a left-eye image and a right-eye image for releasing the mobile terminal from the lock mode; receiving, from a user input unit implemented as a capacitive touch pad, touch inputs or touch-and-drag inputs entered by a user on the displayed button or icon for releasing the mobile terminal from the lock mode; determining whether the user who has entered the touch inputs or the touch-and-drag inputs is already registered in the mobile terminal; correcting a touch-sensing area on the display module if the user is yet to be registered in the mobile terminal; and releasing the mobile terminal from the lock mode; wherein the touch-sensing area is an area within which the presence and location of a touch for selecting the stereoscopic three-dimensional image is sensed; and the determining step further comprising: obtaining capacitance measurements corresponding to each touch input or touch-and-drag input detected in the touch-sensing area of the displayed button or icon; comparing the capacitance measurements with a registered capacitance value; and determining based on the results of the comparison whether the user is registered; and obtaining capacitance measurements corresponding to each touch input or touch-and-drag input detected in the touch-sensing area of the displayed button or icon; comparing the capacitance measurements with a registered capacitance value; and determining based on the results of the comparison whether the user is registered; and the correcting step further comprising: correcting the touch-sensing area by automatically setting, as a background task, the touch-sensing area to a new touch-sensing area based on an average of the capacitance measurements according to the location of the touch inputs which are received within a first area of, a second area of, or a third area of the stereoscopic three-dimensional image and the right-eye image being displayed in the first area, the left-eye image being displayed in the second area, and the third area being an overlapping area of the left-eye and right-eye images.