US Patent 7393149 Compact input device for entering data

A compact input device (104), suitable for entering data in an electronic device (102), includes a cylindrical surface (202) that has a keyboard switch matrix (210) deployed on the outer body of the cylindrical surface (202) formed by a first extendable interlocking part (402) and a second extendable interlocking part (404). The first extendable interlocking part (402) includes a left half of a QWERTY keyboard (e.g., Q, W, E, R, T) while the second extendable interlocking part (404) includes a right half of a QWERTY keyboard (e.g., Y, U, I, O, P). When the compact input device (104) is in an extended and aligned configuration, the keys of the first extendable interlocking part (402) and the keys of the second extendable interlocking part (404) form a common QWERTY keyboard configuration.