Patent ID: 8643603

Claim:
A keypad comprising: a base film having button parts formed on the base film; a light guide layer into which light is guided; and electronic paper which is illuminated by light emitted from the light guide layer, and displays at least one symbol, wherein the electronic paper includes an upper electrode layer, a lower electrode layer, and an ink layer which is interposed between the upper electrode layer and the lower electrode layer and displays a symbol according to an electric field generated by application of voltage to the lower electrode layer, wherein the electronic paper further includes metal areas corresponding to the button parts and non-metal areas disposed between the metal areas so as to provide flexibility for the electronic paper, such that the metal areas and the non-metal areas are formed as a single layer directly disposed on an upper surface of the lower electrode layer, and the non-metal areas are not holes passing through the electronic paper, and wherein signal lines are directly disposed on a lower surface of the lower electrode layer, such that the signal lines pass through the lower electrode layer and are electrically connected to the metal areas disposed on the upper surface of the lower electrode layer, and a protective dummy layer is directly disposed on the lower surface of the lower electrode layer around the signal lines, such that the disposition of the protective dummy layer inhibits concentration of a force towards the signal lines by the electronic paper when the button parts are pressed.