Patent ID: 8106883

Claim:
A mobile terminal, comprising: an optical sensor navigation key adapted to sense a movement direction and a movement speed user contact and generate signals according to the sensed movement direction and the sensed movement speed; an input unit; a display; and a controller adapted to control a function of the mobile terminal in response to the signals generated by the optical sensor navigation key, wherein the controller is further adapted to: cause displaying of at least one menu item and a cursor on the display; cause moving of the displayed cursor toward a location proximate to a specific menu item of the displayed at least one menu item responsive to receiving user input via the input unit; detect the user contact relative to the optical sensor navigation key; activate the optical sensor navigation key after the user contact to the optical sensor navigation key is detected and the cursor is moved to the specific menu item, deactivate the optical sensor navigation key if the user contact to the optical sensor navigation key is not detected within a threshold amount of time after the optical sensor navigation key is activated, determine whether the sensed movement direction is a pre-defined first direction or a pre-defined second direction when the cursor is positioned at the displayed at least one menu item, determine whether the sensed movement speed is greater than a reference value with respect to the pre-defined first direction if the sensed movement direction is the pre-defined first direction, enter an upper menu of the displayed at least one menu item at which the cursor is positioned if the sensed movement speed is greater than the reference value with respect to the pre-defined first direction, cause displaying of the upper menu on the display screen, determine whether the sensed movement speed is greater than the reference value with respect to the pre-defined second direction if the sensed movement direction is the pre-defined second direction and the predetermined pre-defined second direction is opposite to the pre-defined first direction, enter a lower menu of the displayed at least one menu item at which the cursor is positioned if the sensed movement speed is greater than the reference value with respect to the pre-defined second direction, and cause displaying of the lower menu on the display, and wherein the sensed movement speed is an amount of movement per second by the cursor from a first pixel position to a second pixel position on the display.