Apparatus and method for executing functions related to handwritten user input on lock screen

A method of executing a function associated with a handwritten input on a lock screen, the method comprising:

• displaying a first layer of a lock screen on a touch screen;
• receiving an unlock command via the touch screen;
• displaying a second layer of the lock screen on the touch screen when the unlock command is the same as a predetermined unlock command;
• receiving a handwritten input via the touch screen;
• searching for a command corresponding to the handwritten input when the handwritten input is received within a predetermined period of time after displaying the second layer of the lock screen;
• and
• executing the command corresponding to the handwritten input.

An apparatus for executing a function associated with a handwritten input on a lock screen, the apparatus comprising:

• a touch screen configured to display a lock screen;
• and
• a controller configured to
• control the touch screen to display the lock screen,
• receive an unlock command via the touch screen,
• control the touch screen to receive a handwritten input on the displayed lock screen when the unlock command is the same as a predetermined unlock command,
• search for a command corresponding to the handwritten input when the handwritten input is received on the displayed lock screen within a predetermined period of time after determining that the unlock command is the same as the predetermined unlock command, and
• execute the command corresponding to the handwritten input.